PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-25 (1218620)

Clipboard (0)
None

Related Articles

1.  Graphene oxide selectively targets cancer stem cells, across multiple tumor types: Implications for non-toxic cancer treatment, via “differentiation-based nano-therapy” 
Oncotarget  2015;6(6):3553-3562.
Tumor-initiating cells (TICs), a.k.a. cancer stem cells (CSCs), are difficult to eradicate with conventional approaches to cancer treatment, such as chemo-therapy and radiation. As a consequence, the survival of residual CSCs is thought to drive the onset of tumor recurrence, distant metastasis, and drug-resistance, which is a significant clinical problem for the effective treatment of cancer. Thus, novel approaches to cancer therapy are needed urgently, to address this clinical need. Towards this end, here we have investigated the therapeutic potential of graphene oxide to target cancer stem cells. Graphene and its derivatives are well-known, relatively inert and potentially non-toxic nano-materials that form stable dispersions in a variety of solvents. Here, we show that graphene oxide (of both big and small flake sizes) can be used to selectively inhibit the proliferative expansion of cancer stem cells, across multiple tumor types. For this purpose, we employed the tumor-sphere assay, which functionally measures the clonal expansion of single cancer stem cells under anchorage-independent conditions. More specifically, we show that graphene oxide effectively inhibits tumor-sphere formation in multiple cell lines, across 6 different cancer types, including breast, ovarian, prostate, lung and pancreatic cancers, as well as glioblastoma (brain). In striking contrast, graphene oxide is non-toxic for “bulk” cancer cells (non-stem) and normal fibroblasts. Mechanistically, we present evidence that GO exerts its striking effects on CSCs by inhibiting several key signal transduction pathways (WNT, Notch and STAT-signaling) and thereby inducing CSC differentiation. Thus, graphene oxide may be an effective non-toxic therapeutic strategy for the eradication of cancer stem cells, via differentiation-based nano-therapy.
PMCID: PMC4414136  PMID: 25708684
nanomaterials; graphene oxide; cancer stem cells; multiple cancer types: breast; ovarian
2.  Liposome-Formulated siRNA Against Msi1 and Docetaxel Treatment in an Animal Model of Advanced Gastric Adenocarcinoma Eradicates Cancer Stem Cells and Metastasis 
Introduction:
In advanced gastric adenocarcinoma, potent chemoresistant cancer stem cells (CSCs) differentiate into progenitor cells that form all of the cell types in the patient's tumor. Cancer stem cells have genetic mutations that render them resistant to chemotherapy- or radiation-induced injury due to rapid repair of DNA damage. The goal of this study was to use antisense molecular targeting to eradicate cancer stem cells, as well as docetaxel, thus eliminating tumor cells and potential recurrence and metastasis in a gastric cancer model.
Materials and Methods:
Tumor cells that overexpressed bcl-2 and CSCs were obtained from chemoresistant patients with metastatic advanced gastric adenocarcinoma. The CSCs overexpressed Msi1, which activates Notch and Wnt pathways. The tumor cells were orthotopically transplanted into genetically engineered immunodeficient mice, which developed a tumor with the same cell types as in the human tumor. The animals were treated with pegylated liposomes composed of phospholipids with high transition temperature (Tc). We entrapped docetaxel in the acyl chains, and encapsulated a 21-base pair of small interfering RNA (siRNA) strand targeted to Msi1 in the liposomes. This colloidal formulation was termed LP/AS-Msi1/TXT (under patent).
Results:
Post-treatment, the endocytosed siRNA unwound and was incorporated into RNA-induced silencing complex (RISC), which is a stable protein-RNA complex. siRNA was then directed to the targeted Msi1 messenger RNA (mRNA), which is involved in the cancer stem cell pathway. The Msi1 mRNA undergoes cleavage and degradation, interrupting the protein synthesis of the targeted Msi1 gene. This causes downregulation of Wnt-suppressing cell proliferation, migration of cancer stem cells by inhibiting angiogenesis after VEGF downregulation, and induction of apoptosis after downregulation of antiapoptotic caspase inhibitor survivin. Furthermore, siRNA against Msi1 inhibits degrading proteases of extracellular matrix, such as MMP26 and matrilysin, and cell adhesion molecules, such as neuronal cell adhesion molecule (NRCAM) and CD44, inhibiting invasion and metastasis. Also, blockage of the Wnt signaling cascade led to inhibition of cancer progenitor cells by downregulation of NRSF/REST and ENC1 with BTB-like domain genes. It also blocked tumorigenesis by downregulating claudin1, which leads to inhibition of the Ctnn-Beta-TCF/LEF signaling pathway. Downregulation of Msi1 inhibited the Notch signaling pathway, blocking nuclear transcription factors, downregulating genes, and inhibiting proteins involved in the self-renewal and regeneration of cancer stem cells (which might be considered the roots of the gastric adenocarcinoma tree), leading to their eradication by inhibiting mitotic divisions. Docetaxel treatment, via cell signaling mechanisms, eradicated tumor cells (the leaves of the gastric adenocarcinoma tree) by phosphorylating antiapoptotic oncogene bcl-2, leading to induction of apoptosis, or type I programmed cell death (PCD). Downregulation of bcl-2 led to upregulation of tumor suppressor gene Beclin-1, inducing autophagy, or type II PCD. Polymerization of microtubules led to cell cycle blockage, inhibiting mitosis. BrdU and MTT assays exhibited inhibition of DNA synthesis and metabolic activity, respectively. Polymerization of microtubules led to cell cycle blockage, inhibiting mitosis. Transmission electron microscopy demonstrated a phagocytic bystander killing effect mediated by APCs, and adjacent tumor cells. Finally, we observed morphologic and metabolic evidence of inhibition of tumor recurrence and metastasis on computed tomography and positron emission tomography scans, respectively.
Conclusion:
The novel therapy, LP/AS-Msi1/TXT, is designed to target cancer stem cells by inhibiting vital pathways, thus eradicating the “roots” of advanced gastric adenocarcinoma recurrence and metastasis, while the co-administered, conventional chemotherapeutic agent docetaxel eradicates the tumor cells (or the “leaves” of advanced gastric adenocarcinoma). LP/AS-Msi1/TXT represents a potential tailored approach to target cancer stem cells with less toxicity than observed with conventional chemotherapy.
PMCID: PMC3056302
3.  The Stemness Phenotype Model 
ISRN Oncology  2012;2012:392647.
The identification of a fraction of cancer stem cells (CSCs) associated with resistance to chemotherapy in most solid tumors leads to the dogma that eliminating this fraction will cure cancer. Experimental data has challenged this simplistic and optimistic model. Opposite to the classical cancer stem cell model, we introduced the stemness phenotype model (SPM), which proposed that all glioma cells possess stem cell properties and that the stemness is modulated by the microenvironment. A key prediction of the SPM is that to cure gliomas all gliomas cells (CSCs and non-CSCs) should be eliminated at once. Other theories closely resembling the SPM and its predictions have recently been proposed, suggesting that the SPM may be a useful model for other type of tumors. Here, we review data from other tumors that strongly support the concepts of the SPM applied to gliomas. We include data related to: (1) the presence of a rare but constant fraction of CSCs in established cancer cell lines, (2) the clonal origin of cancer, (3) the symmetrical division, (4) the ability of “non-CSCs” to generate “CSCs,” and (5) the effect of the microenvironment on cancer stemness. The aforenamed issues that decisively supported the SPM proposed for gliomas can also be applied to breast, lung, prostate cancer, and melanoma and perhaps other tumors in general. If the glioma SPM is correct and can be extrapolated to other types of cancer, it will have profound implications in the development of novel modalities for cancer treatment.
doi:10.5402/2012/392647
PMCID: PMC3423925  PMID: 22928120
4.  Antibiotics that target mitochondria effectively eradicate cancer stem cells, across multiple tumor types: Treating cancer like an infectious disease 
Oncotarget  2015;6(7):4569-4584.
Here, we propose a new strategy for the treatment of early cancerous lesions and advanced metastatic disease, via the selective targeting of cancer stem cells (CSCs), a.k.a., tumor-initiating cells (TICs). We searched for a global phenotypic characteristic that was highly conserved among cancer stem cells, across multiple tumor types, to provide a mutation-independent approach to cancer therapy. This would allow us to target cancer stem cells, effectively treating cancer as a single disease of “stemness”, independently of the tumor tissue type. Using this approach, we identified a conserved phenotypic weak point – a strict dependence on mitochondrial biogenesis for the clonal expansion and survival of cancer stem cells. Interestingly, several classes of FDA-approved antibiotics inhibit mitochondrial biogenesis as a known “side-effect”, which could be harnessed instead as a “therapeutic effect”. Based on this analysis, we now show that 4-to-5 different classes of FDA-approved drugs can be used to eradicate cancer stem cells, in 12 different cancer cell lines, across 8 different tumor types (breast, DCIS, ovarian, prostate, lung, pancreatic, melanoma, and glioblastoma (brain)). These five classes of mitochondrially-targeted antibiotics include: the erythromycins, the tetracyclines, the glycylcyclines, an anti-parasitic drug, and chloramphenicol. Functional data are presented for one antibiotic in each drug class: azithromycin, doxycycline, tigecycline, pyrvinium pamoate, as well as chloramphenicol, as proof-of-concept. Importantly, many of these drugs are non-toxic for normal cells, likely reducing the side effects of anti-cancer therapy. Thus, we now propose to treat cancer like an infectious disease, by repurposing FDA-approved antibiotics for anti-cancer therapy, across multiple tumor types. These drug classes should also be considered for prevention studies, specifically focused on the prevention of tumor recurrence and distant metastasis. Finally, recent clinical trials with doxycycline and azithromycin (intended to target cancer-associated infections, but not cancer cells) have already shown positive therapeutic effects in cancer patients, although their ability to eradicate cancer stem cells was not yet appreciated.
PMCID: PMC4467100  PMID: 25625193
mitochondria; mitochondrial biogenesis; cancer stem cells; tumor initiating cells; antibiotics
5.  Oncolytic vaccinia virus GLV-1h68 strain shows enhanced replication in human breast cancer stem-like cells in comparison to breast cancer cells 
Background
Recent data suggest that cancer stem cells (CSCs) play an important role in cancer, as these cells possess enhanced tumor-forming capabilities and are responsible for relapses after apparently curative therapies have been undertaken. Hence, novel cancer therapies will be needed to test for both tumor regression and CSC targeting. The use of oncolytic vaccinia virus (VACV) represents an attractive anti-tumor approach and is currently under evaluation in clinical trials. The purpose of this study was to demonstrate whether VACV does kill CSCs that are resistant to irradiation and chemotherapy.
Methods
Cancer stem-like cells were identified and separated from the human breast cancer cell line GI-101A by virtue of increased aldehyde dehydrogenase 1 (ALDH1) activity as assessed by the ALDEFLUOR assay and cancer stem cell-like features such as chemo-resistance, irradiation-resistance and tumor-initiating were confirmed in cell culture and in animal models. VACV treatments were applied to both ALDEFLUOR-positive cells in cell culture and in xenograft tumors derived from these cells. Moreover, we identified and isolated CD44+CD24+ESA+ cells from GI-101A upon an epithelial-mesenchymal transition (EMT). These cells were similarly characterized both in cell culture and in animal models.
Results
We demonstrated for the first time that the oncolytic VACV GLV-1h68 strain replicated more efficiently in cells with higher ALDH1 activity that possessed stem cell-like features than in cells with lower ALDH1 activity. GLV-1h68 selectively colonized and eventually eradicated xenograft tumors originating from cells with higher ALDH1 activity. Furthermore, GLV-1h68 also showed preferential replication in CD44+CD24+ESA+ cells derived from GI-101A upon an EMT induction as well as in xenograft tumors originating from these cells that were more tumorigenic than CD44+CD24-ESA+ cells.
Conclusions
Taken together, our findings indicate that GLV-1h68 efficiently replicates and kills cancer stem-like cells. Thus, GLV-1h68 may become a promising agent for eradicating both primary and metastatic tumors, especially tumors harboring cancer stem-like cells that are resistant to chemo and/or radiotherapy and may be responsible for recurrence of tumors.
doi:10.1186/1479-5876-10-167
PMCID: PMC3478222  PMID: 22901246
Aldehyde dehydrogenase 1; Cancer stem cells; Oncolytic virotherapy; Vaccinia virus; EMT
6.  Berberis libanotica Ehrenb Extract Shows Anti-Neoplastic Effects on Prostate Cancer Stem/Progenitor Cells 
PLoS ONE  2014;9(11):e112453.
Cancer stem cells (CSCs), including those of advanced prostate cancer, are a suggested reason for tumor resistance toward conventional tumor therapy. Therefore, new therapeutic agents are urgently needed for targeting CSCs. Despite the minimal understanding of their modes of action, natural products and herbal therapies have been commonly used in the prevention and treatment of many cancers. Berberis libanotica Ehrenb (BLE) is a plant rich in alkaloids which may possess anti-cancer activity and a high potential for eliminating CSCs. We tested the effect of BLE on prostate cancer cells and our data indicated that this extract induced significant reduction in cell viability and inhibited the proliferation of human prostate cancer cell lines (DU145, PC3 and 22Rv1) in a dose- and time-dependent manner. BLE extract induced a perturbation of the cell cycle, leading to a G0-G1 arrest. Furthermore, we noted 50% cell death, characterized by the production of high levels of reactive oxidative species (ROS). Inhibition of cellular migration and invasion was also achieved upon treatment with BLE extract, suggesting a role in inhibiting metastasis. Interestingly, BLE extract had a major effect on CSCs. Cells were grown in a 3D sphere-formation assay to enrich for a population of cancer stem/progenitor cells. Our results showed a significant reduction in sphere formation ability. Three rounds of treatment with BLE extract were sufficient to eradicate the self-renewal ability of highly resistant CSCs. In conclusion, our results suggest a high therapeutic potential of BLE extract in targeting prostate cancer and its CSCs.
doi:10.1371/journal.pone.0112453
PMCID: PMC4224486  PMID: 25380390
7.  Combination of dasatinib and curcumin eliminates chemo-resistant colon cancer cells 
Metastatic colorectal cancer remains a serious health concern with poor patient survival. Although 5-Fluorouracil (5-FU) or 5-FU plus oxaliplatin (FOLFOX) is the standard therapy for colorectal cancer, it has met with limited success. Recurrence of the tumor after chemotherapy could partly be explained by the enrichment of the chemo-resistant sub-population of cancer stem cells (CSCs) that possess the ability for self-renewal and differentiation into different lineages in the tumor. Therefore development of therapeutic strategies that target CSCs for successful treatment of this malignancy is warranted. The current investigation was undertaken to examine the effectiveness of the combination therapy of dasatinib (a Src inhibitor) and curcumin (a dietary agent with pleiotropic effect) in inhibiting the growth and other properties of carcinogenesis of chemo-resistant colon cancer cells that are enriched in CSCs sub-population. Remnants of spontaneous adenomas from APCMin +/- mice treated with dasatinib and/or curcumin were analyzed for several cancer stem cell markers (ALDH, CD44, CD133 and CD166). Human colon cancer cells HCT-116 (p53 wild type; K-ras mutant) and HT-29 (p53 mutant; K-ras wild type) were used to generate FOLFOX resistant (referred to as CR) cells. The effectiveness of the combination therapy in inhibiting growth, invasive potential and stemness was examined in colon cancer CR cells. The residual tumors from APCMin +/- mice treated with dasatinib and/or curcumin showed 80-90% decrease in the expression of the CSC markers ALDH, CD44, CD133, CD166. The colon cancer CR cells showed a higher expression of CSCs markers, cell invasion potential and ability to form colonospheres, compared to the corresponding parental cells. The combination therapy of dasatinib and curcumin demonstrated synergistic interactions in CR HCT-116 and CR HT-29 cells, as determined by Calcusyn analysis. The combinatorial therapy inhibited cellular growth, invasion and colonosphere formation and also reduced CSC population as evidenced by the decreased expression of CSC specific markers: CD133, CD44, CD166 and ALDH. Our data suggest that the combination therapy of dasatinib and curcumin may be a therapeutic strategy for re-emergence of chemo-resistant colon cancer by targeting CSC sub-population.
doi:10.1186/1750-2187-6-7
PMCID: PMC3162943  PMID: 21774804
8.  In vitro and in vivo antiproliferative activity of metformin on stem-like cells isolated from spontaneous canine mammary carcinomas: translational implications for human tumors 
BMC Cancer  2015;15:228.
Background
Cancer stem cells (CSCs) are considered the cell subpopulation responsible for breast cancer (BC) initiation, growth, and relapse. CSCs are identified as self-renewing and tumor-initiating cells, conferring resistance to chemo- and radio-therapy to several neoplasias. Nowadays, th (about 10mM)e pharmacological targeting of CSCs is considered an ineludible therapeutic goal. The antidiabetic drug metformin was reported to suppress in vitro and in vivo CSC survival in different tumors and, in particular, in BC preclinical models. However, few studies are available on primary CSC cultures derived from human postsurgical BC samples, likely because of the limited amount of tissue available after surgery. In this context, comparative oncology is acquiring a relevant role in cancer research, allowing the analysis of larger samples from spontaneous pet tumors that represent optimal models for human cancer.
Methods
Isolation of primary canine mammary carcinoma (CMC) cells and enrichment in stem-like cell was carried out from fresh tumor specimens by culturing cells in stem-permissive conditions. Phenotypic and functional characterization of CMC-derived stem cells was performed in vitro, by assessment of self-renewal, long-lasting proliferation, marker expression, and drug sensitivity, and in vivo, by tumorigenicity experiments. Corresponding cultures of differentiated CMC cells were used as internal reference. Metformin efficacy on CMC stem cell viability was analyzed both in vitro and in vivo.
Results
We identified a subpopulation of CMC cells showing human breast CSC features, including expression of specific markers (i.e. CD44, CXCR4), growth as mammospheres, and tumor-initiation in mice. These cells show resistance to doxorubicin but were highly sensitive to metformin in vitro. Finally, in vivo metformin administration significantly impaired CMC growth in NOD-SCID mice, associated with a significant depletion of CSCs.
Conclusions
Similarly to the human counterpart, CMCs contain stem-like subpopulations representing, in a comparative oncology context, a valuable translational model for human BC, and, in particular, to predict the efficacy of antitumor drugs. Moreover, metformin represents a potential CSC-selective drug for BC, as effective (neo-)adjuvant therapy to eradicate CSC in mammary carcinomas of humans and animals.
Electronic supplementary material
The online version of this article (doi:10.1186/s12885-015-1235-8) contains supplementary material, which is available to authorized users.
doi:10.1186/s12885-015-1235-8
PMCID: PMC4397725  PMID: 25884842
Breast cancer; Cancer stem cells; Metformin; Comparative oncology
9.  Targeting CD133 in an in vivo ovarian cancer model reduces ovarian cancer progression 
Gynecologic oncology  2013;130(3):579-587.
Objectives
While most women with ovarian cancer will achieve complete remission after treatment, the majority will relapse within two years, highlighting the need for novel therapies. Cancer stem cells (CSC) have been identified in ovarian cancer and most other carcinomas as a small population of cells that can self-renew. CSC are more chemoresistant and radio-resistant than the bulk tumor cells; it is likely that CSC are responsible for relapse, the major problem in cancer treatment. CD133 has emerged as one of the most promising markers for CSC in ovarian cancer. The hypothesis driving this study is that despite their low numbers in ovarian cancer tumors, CSC can be eradicated using CD133 targeted therapy and tumor growth can be inhibited.
Methods
Ovarian cancer cell lines were evaluated using flow cytometry for expression of CD133. In vitro viability studies with an anti-CD133 targeted toxin were performed on one of the cell lines, NIH:OVCAR5. The drug was tested in vivo using a stably transfected luciferase-expressing NIH:OVCAR5 subline in nude mice, so that tumor growth could be monitored by digital imaging in real time.
Results
Ovarian cancer cell lines showed 5.6% to 16.0% CD133 expression. dCD133KDEL inhibited the in vitro growth of NIH:OVCAR5 cells. Despite low numbers of CD133-expressing cells in the tumor population, intraperitoneal drug therapy caused a selective decrease in tumor progression in intraperitoneal NIH: OVCAR5-luc tumors.
Conclusions
Directly targeting CSC that are a major cause of drug resistant tumor relapse with an anti-CD133 targeted toxin shows promise for ovarian cancer therapy.
doi:10.1016/j.ygyno.2013.05.027
PMCID: PMC3906852  PMID: 23721800
Ovarian cancer; CD133; Xenograft model; Cancer stem cells; Targeted toxin
10.  Cancer stem cells and human malignant melanoma 
Summary
Cancer stem cells (CSC) have been identified in hematological malignancies and several solid cancers. Similar to physiological stem cells, CSC are capable of self-renewal and differentiation and have the potential for indefinite proliferation, a function through which they may cause tumor growth. Although conventional anti-cancer treatments might eradicate most malignant cells in a tumor, they are potentially ineffective against chemoresistant CSC, which may ultimately be responsible for recurrence and progression. Human malignant melanoma is a highly aggressive and drug-resistant cancer. Detection of tumor heterogeneity, undifferentiated molecular signatures, and increased tumorigenicity of melanoma subsets with embryonic-like differentiation plasticity strongly suggest the presence and involvement of malignant melanoma stem cells (MMSC) in the initiation and propagation of this malignancy. Here, we review these findings in the context of functional properties ascribed to melanocyte stem cells and CSC in other cancers. We discuss the association of deregulated signaling pathways, genomic instability, and vasculogenic mimicry phenomena observed in melanoma subpopulations in light of the CSC concept. We propose that a subset of MMSC may be responsible for melanoma therapy-resistance, tumor invasiveness, and neoplastic progression and that targeted abrogation of a MMSC compartment could therefore ultimately lead to stable remissions and perhaps cures of metastatic melanoma.
doi:10.1111/j.1755-148X.2007.00427.x
PMCID: PMC2885609  PMID: 18353142
melanoma; cancer stem cells; tumorigenicity; self-renewal; differentiation; progression; chemoresistance
11.  Adenovirus adenine nucleotide translocator-2 shRNA effectively induces apoptosis and enhances chemosensitivity by the down-regulation of ABCG2 in breast cancer stem-like cells 
Experimental & Molecular Medicine  2011;44(4):251-259.
Cancer stem cells (CSCs) are resistant to chemo- and radio-therapy, and can survive to regenerate new tumors. This is an important reason why various anti-cancer therapies often fail to completely control tumors, although they kill and eliminate the bulk of cancer cells. In this study, we determined whether or not adenine nucleotide translocator-2 (ANT2) suppression could also be effective in inducing cell death of breast cancer stem-like cells. A sub-population (SP; CD44+/CD24-) of breast cancer cells has been reported to have stem/progenitor cell properties. We utilized the adeno-ANT2 shRNA virus to inhibit ANT2 expression and then observed the treatment effect in a SP of breast cancer cell line. In this study, MCF7, MDA-MB-231 cells, and breast epithelial cells (MCF10A) mesenchymally-transdifferentiated through E-cadherin knockdown were used. ANT2 expression was high in both stem-like cells and non-stem-like cells of MCF7 and MDA-MB-231 cells, and was induced and up-regulated by mesenchymal transdifferentiation in MCF10A cells (MCF10AEMT). Knockdown of ANT2 by adeno-shRNA virus efficiently induced apoptotic cell death in the stem-like cells of MCF7 and MDA-MB-231 cells, and MCF10AEMT. Stem-like cells of MCF7 and MDA-MB-231, and MCF10AEMT cells exhibited increased drug (doxorubicin) resistance, and expressed a multi-drug resistant related molecule, ABCG2, at a high level. Adeno-ANT2 shRNA virus markedly sensitized the stem-like cells of MCF7 and MDA-MB-231, and the MCF10AEMT cells to doxorubicin, which was accompanied by down-regulation of ABCG2. Our results suggest that ANT2 suppression by adeno-shRNA virus is an effective strategy to induce cell death and increase the chemosensitivity of stem-like cells in breast cancer.
doi:10.3858/emm.2012.44.4.019
PMCID: PMC3349907  PMID: 22198296
ABCG2 protein, human; adenine nucleotide translocator 2; drug therapy, combination; gene therapy; neoplastic stem cells; RNA, small interfering
12.  Human Pancreatic Cancer Stem Cells: Implications for How We Treat Pancreatic Cancer 
Translational Oncology  2008;1(1):14-18.
Pancreatic cancer has the worst prognosis of any major malignancy, with an annual death rate that approximates the annual incidence rate. Delayed diagnosis, relative chemotherapy and radiation resistance and an intrinsic biologic aggressiveness all contribute to the abysmal prognosis associated with pancreatic cancer. Answers to the frustrating effort to find effective therapies for pancreatic cancer may be gained through a renewed perspective on tumorigenesis as a process governed by a select population of cells, termed cancer stem cells (CSCs). Cancer stem cells, like their normal counterparts, have the properties of self-renewal and multilineage differentiation and possess inherently heightened DNA damage response and repair mechanisms that make them difficult to eradicate. Initially discovered in leukemias, researchers have identified CSCs in several solid-organ malignancies including breast, brain, prostate, and colon cancers. We have recently identified a CSC population in human pancreatic cancers. These pancreatic CSC represent 0.5% to 1.0% of all pancreatic cancer cells and express the cell surface markers CD44, CD24, and epithelial-specific antigen. Pancreatic CSCs have been shown to be resistant to standard chemotherapy and radiation, and devising specific therapies to target this distinct cell population is likely needed to identify effective therapies to treat this dismal disease.
PMCID: PMC2510763  PMID: 18607507
13.  Regulation of Ovarian Cancer Stem Cells or Tumor-Initiating Cells 
Cancer stem cells or tumor-initiating cells (CSC/TICs), which can undergo self-renewal and differentiation, are thought to play critical roles in tumorigenesis, therapy resistance, tumor recurrence and metastasis. Tumor recurrence and chemoresistance are major causes of poor survival rates of ovarian cancer patients, which may be due in part to the existence of CSC/TICs. Therefore, elucidating the molecular mechanisms responsible for the ovarian CSC/TICs is required to develop a cure for this malignancy. Recent studies have indicated that the properties of CSC/TICs can be regulated by microRNAs, genes and signaling pathways which also function in normal stem cells. Moreover, emerging evidence suggests that the tumor microenvironments surrounding CSC/TICs are crucial for the maintenance of these cells. Similarly, efforts are now being made to unravel the mechanism involved in the regulation of ovarian CSC/TICs, although much work is still needed. This review considers recent advances in identifying the genes and pathways involved in the regulation of ovarian CSC/TICs. Furthermore, current approaches targeting ovarian CSC/TICs are described. Targeting both CSC/TICs and bulk tumor cells is suggested as a more effective approach to eliminating ovarian tumors. Better understanding of the regulation of ovarian CSC/TICs might facilitate the development of improved therapeutic strategies for recurrent ovarian cancer.
doi:10.3390/ijms14046624
PMCID: PMC3645658  PMID: 23528891
cancer stem cell or tumor-initiating cells (CSC/TICs); chemoresistance; microRNA; ovarian cancer; recurrence; tumor microenvironment
14.  Protein kinase C-delta inactivation inhibits the proliferation and survival of cancer stem cells in culture and in vivo 
BMC Cancer  2014;14:90.
Background
A subpopulation of tumor cells with distinct stem-like properties (cancer stem-like cells, CSCs) may be responsible for tumor initiation, invasive growth, and possibly dissemination to distant organ sites. CSCs exhibit a spectrum of biological, biochemical, and molecular features that are consistent with a stem-like phenotype, including growth as non-adherent spheres (clonogenic potential), ability to form a new tumor in xenograft assays, unlimited self-renewal, and the capacity for multipotency and lineage-specific differentiation. PKCδ is a novel class serine/threonine kinase of the PKC family, and functions in a number of cellular activities including cell proliferation, survival or apoptosis. PKCδ has previously been validated as a synthetic lethal target in cancer cells of multiple types with aberrant activation of Ras signaling, using both genetic (shRNA and dominant-negative PKCδ mutants) and small molecule inhibitors. In contrast, PKCδ is not required for the proliferation or survival of normal cells, suggesting the potential tumor-specificity of a PKCδ-targeted approach.
Methods
shRNA knockdown was used validate PKCδ as a target in primary cancer stem cell lines and stem-like cells derived from human tumor cell lines, including breast, pancreatic, prostate and melanoma tumor cells. Novel and potent small molecule PKCδ inhibitors were employed in assays monitoring apoptosis, proliferation and clonogenic capacity of these cancer stem-like populations. Significant differences among data sets were determined using two-tailed Student’s t tests or ANOVA.
Results
We demonstrate that CSC-like populations derived from multiple types of human primary tumors, from human cancer cell lines, and from transformed human cells, require PKCδ activity and are susceptible to agents which deplete PKCδ protein or activity. Inhibition of PKCδ by specific genetic strategies (shRNA) or by novel small molecule inhibitors is growth inhibitory and cytotoxic to multiple types of human CSCs in culture. PKCδ inhibition efficiently prevents tumor sphere outgrowth from tumor cell cultures, with exposure times as short as six hours. Small-molecule PKCδ inhibitors also inhibit human CSC growth in vivo in a mouse xenograft model.
Conclusions
These findings suggest that the novel PKC isozyme PKCδ may represent a new molecular target for cancer stem cell populations.
doi:10.1186/1471-2407-14-90
PMCID: PMC3927586  PMID: 24528676
Protein Kinase C isozymes; Synthetic lethal interaction; Cancer-initiating cell; Xenograft tumor model
15.  Krüppel-Like Factor 4 Acts as an Oncogene in Colon Cancer Stem Cell-Enriched Spheroid Cells 
PLoS ONE  2013;8(2):e56082.
Cancer stem cells (CSCs), a rare population in any type of cancers, including colon cancer, are tumorigenic. It has been thought that CSCs are responsible for cancer recurrence, metastasis, and drug resistance. Isolating CSCs in colon cancers is challenging, and thus the molecular mechanism regulating the self-renewing and differentiation of CSCs remains unknown. We cultured DLD-1 cells, one of types of cells derived from colon cancers, in serum-free medium to obtain spheroid cells. These cells possessed the characteristics of CSCs, with the expression of CD133, CD166, Lgr5, and ALDH1, higher capacities of chemo-resistance, migration, invasion, and tumorigenicity in vitro and in vivo than the adherent DLD-1 cells. Krüppel-like factor 4 (KLF4) is essential factor for maintaining self-renewal of adult and embryonic stem cells. It has been used to induce pluripotent stem cells (iPS) from somatic cells. Since KLF4 is expressed in colon cancer cells, we investigated its role in spheroid cells isolated from DLD-1 cells and found that KLF4 was overexpressed only in spheroid cells and reducing the expression of KLF4 by short-hairpin RNA significantly decreased the capacities of these cells to resist the chemicals, migrate, invade, and generate tumors in vitro and in vivo. The spheroid cells with reduced KLF4 expression also had decreased expression of CSCs markers and mesenchymal markers. Taken together, culturing DLD-1 cells in serum-free medium enriches CSCs and the expression of KLF4 is essential for the characteristics of CSCs in DLD-1; thus KLF4 can be a potential therapeutic target for treating colon cancer.
doi:10.1371/journal.pone.0056082
PMCID: PMC3572033  PMID: 23418515
16.  The dietary bioflavonoid quercetin synergizes with epigallocathechin gallate (EGCG) to inhibit prostate cancer stem cell characteristics, invasion, migration and epithelial-mesenchymal transition 
Background
Much attention has been recently focused on the role of cancer stem cells (CSCs) in the initiation and progression of solid malignancies. Since CSCs are able to proliferate and self-renew extensively due to their ability to express anti-apoptotic and drug resistant proteins, thus sustaining tumor growth. Therefore, the strategy to eradicate CSCs might have significant clinical implications. The objectives of this study were to examine the molecular mechanisms by which epigallocathechin gallate (EGCG) inhibits stem cell characteristics of prostate CSCs, and synergizes with quercetin, a major polyphenol and flavonoid commonly detected in many fruits and vegetables.
Results
Our data indicate that human prostate cancer cell lines contain a small population of CD44+CD133+ cancer stem cells and their self-renewal capacity is inhibited by EGCG. Furthermore, EGCG inhibits the self-renewal capacity of CD44+α2β1+CD133+ CSCs isolated from human primary prostate tumors, as measured by spheroid formation in suspension. EGCG induces apoptosis by activating capase-3/7 and inhibiting the expression of Bcl-2, survivin and XIAP in CSCs. Furthermore, EGCG inhibits epithelial-mesenchymal transition by inhibiting the expression of vimentin, slug, snail and nuclear β-catenin, and the activity of LEF-1/TCF responsive reporter, and also retards CSC's migration and invasion, suggesting the blockade of signaling involved in early metastasis. Interestingly, quercetin synergizes with EGCG in inhibiting the self-renewal properties of prostate CSCs, inducing apoptosis, and blocking CSC's migration and invasion. These data suggest that EGCG either alone or in combination with quercetin can eliminate cancer stem cell-characteristics.
Conclusion
Since carcinogenesis is a complex process, combination of bioactive dietary agents with complementary activities will be beneficial for prostate cancer prevention and/ortreatment.
doi:10.1186/1750-2187-5-14
PMCID: PMC2933702  PMID: 20718984
17.  Survival of the Fittest: Cancer Stem Cells in Therapeutic Resistance and Angiogenesis 
In an increasing number of cancers, tumor populations called cancer stem cells (CSCs) or tumor initiating cells have been defined in functional assays of self-renewal and tumor initiation. Moreover, recent work in several different cancers has suggested the CSC population as a source of chemo- and radiation-therapy resistance within tumors. Work in glioblastoma and breast cancers supports the idea that CSCs may possess innate resistance mechanisms against radiation- and chemotherapy-induced cancer cell death, allowing them to survive and initiate tumor recurrence. Several resistance mechanisms have been proposed, including amplified checkpoint activation and DNA damage repair as well as increased Wnt/β-Catenin and Notch signalling. Novel targeted therapies against the DNA damage checkpoint or stem cell maintenance pathways may sensitize CSCs to radiation or other therapies. Another important category of cancer therapies are anti-angiogenic and vascular targeting agents which are also becoming integrated in the treatment paradigm of an increasing number of cancers. Recent results from our laboratory and others support a role for CSCs in the angiogenic drive as well as the mechanism of anti-angiogenic agents. Identifying and targeting the molecular mechanisms responsible for CSC therapeutic resistance may improve the efficacy of current cancer therapies.
doi:10.1200/JCO.2007.15.1829
PMCID: PMC2739000  PMID: 18539962
18.  Quiescent, Slow-Cycling Stem Cell Populations in Cancer: A Review of the Evidence and Discussion of Significance 
Journal of Oncology  2010;2011:396076.
Long-lived cancer stem cells (CSCs) with indefinite proliferative potential have been identified in multiple epithelial cancer types. These cells are likely derived from transformed adult stem cells and are thought to share many characteristics with their parental population, including a quiescent slow-cycling phenotype. Various label-retaining techniques have been used to identify normal slow cycling adult stem cell populations and offer a unique methodology to functionally identify and isolate cancer stem cells. The quiescent nature of CSCs represents an inherent mechanism that at least partially explains chemotherapy resistance and recurrence in posttherapy cancer patients. Isolating and understanding the cell cycle regulatory mechanisms of quiescent cancer cells will be a key component to creation of future therapies that better target CSCs and totally eradicate tumors. Here we review the evidence for quiescent CSC populations and explore potential cell cycle regulators that may serve as future targets for elimination of these cells.
doi:10.1155/2011/396076
PMCID: PMC2948913  PMID: 20936110
19.  Salinomycin as a Drug for Targeting Human Cancer Stem Cells 
Cancer stem cells (CSCs) represent a subpopulation of tumor cells that possess self-renewal and tumor initiation capacity and the ability to give rise to the heterogenous lineages of malignant cells that comprise a tumor. CSCs possess multiple intrinsic mechanisms of resistance to chemotherapeutic drugs, novel tumor-targeted drugs, and radiation therapy, allowing them to survive standard cancer therapies and to initiate tumor recurrence and metastasis. Various molecular complexes and pathways that confer resistance and survival of CSCs, including expression of ATP-binding cassette (ABC) drug transporters, activation of the Wnt/β-catenin, Hedgehog, Notch and PI3K/Akt/mTOR signaling pathways, and acquisition of epithelial-mesenchymal transition (EMT), have been identified recently. Salinomycin, a polyether ionophore antibiotic isolated from Streptomyces albus, has been shown to kill CSCs in different types of human cancers, most likely by interfering with ABC drug transporters, the Wnt/β-catenin signaling pathway, and other CSC pathways. Promising results from preclinical trials in human xenograft mice and a few clinical pilote studies reveal that salinomycin is able to effectively eliminate CSCs and to induce partial clinical regression of heavily pretreated and therapy-resistant cancers. The ability of salinomycin to kill both CSCs and therapy-resistant cancer cells may define the compound as a novel and an effective anticancer drug.
doi:10.1155/2012/950658
PMCID: PMC3516046  PMID: 23251084
20.  Cancer stem cells in surgery 
Il Giornale di Chirurgia  2015;35(11-12):257-259.
The Cancer Stem Cells (CSC) hypothesis is based on three fundamental ideas: 1) the similarities in the mechanisms that regulate self-renewal of normal stem cells and cancer cells; 2) the possibility that tumour cells might arise from normal stem cells; 3) the notion that tumours might contain ‘cancer stem cells’ - rare cells with indefinite proliferative potential that drive the formation and growth of tumours.
The roles for cancer stem cells have been demonstrated for some cancers, such as cancers of the hematopoietic system, breast, brain, prostate, pancreas and liver.
The attractive idea about cancer stem cell hypothesis is that it could partially explain the concept of minimal residual disease. After surgical macroscopically zero residual (R0) resections, even the persistence of one single cell nestling in one of the so called “CSCs niches” could give rise to distant relapse.
Furthermore the metastatic cells can remain in a “dormant status” and give rise to disease after long period of apparent disease free. These cells in many cases have acquired resistance traits to chemo and radiotherapy making adjuvant treatment vain.
Clarifying the role of the cancer stem cells and their implications in the oncogenesis will play an important role in the management of cancer patient by identifying new prospective for drugs and specific markers to prevent and monitoring relapse and metastasis.
The identification of the niche where the CSCs reside in a dormant status might represent a valid instrument to follow-up patients also after having obtained a R0 surgical resection. What we believe is that if new diagnostic instruments were developed specifically to identify the localization and status of activity of the CSCs during tumor dormancy, this would lead to impressive improvement in the early detection and management of relapse and metastasis.
PMCID: PMC4321502  PMID: 25644725
Cancer stem cells (CSC); Relapse; Metastasis; CSCs niches; R0 surgical resection
21.  Basal/HER2 breast carcinomas 
Cell Cycle  2013;12(2):225-245.
High rates of inherent primary resistance to the humanized monoclonal antibody trastuzumab (Herceptin) are frequent among HER2 gene-amplified breast carcinomas in both metastatic and adjuvant settings. The clinical efficacy of trastuzumab is highly correlated with its ability to specifically and efficiently target HER2-driven populations of breast cancer stem cells (CSCs). Intriguingly, many of the possible mechanisms by which cancer cells escape trastuzumab involve many of the same biomarkers that have been implicated in the biology of CS-like tumor-initiating cells. In the traditional, one-way hierarchy of CSCs in which all cancer cells descend from special self-renewing CSCs, HER2-positive CSCs can occur solely by self-renewal. Therefore, by targeting CSC self-renewal and resistance, trastuzumab is expected to induce tumor shrinkage and further reduce breast cancer recurrence rates when used alongside traditional therapies. In a new, alternate model, more differentiated non-stem cancer cells can revert to trastuzumab-refractory, CS-like cells via the activation of intrinsic or microenvironmental paths-to-stemness, such as the epithelial-to-mesenchymal transition (EMT). Alternatively, stochastic transitions of trastuzumab-responsive CSCs might also give rise to non-CSC cellular states that lack major attributes of CSCs and, therefore, can remain “hidden” from trastuzumab activity. Here, we hypothesize that a better understanding of the CSC/non-CSC social structure within HER2-overexpressing breast carcinomas is critical for trastuzumab-based treatment decisions in the clinic. First, we decipher the biological significance of CSC features and the EMT on the molecular effects and efficacy of trastuzumab in HER2-positive breast cancer cells. Second, we reinterpret the genetic heterogeneity that differentiates trastuzumab-responders from non-responders in terms of CSC cellular states. Finally, we propose that novel predictive approaches aimed at better forecasting early tumor responses to trastuzumab should identify biological determinants that causally underlie the intrinsic flexibility of HER2-positive CSCs to “enter” into or “exit” from trastuzumab-sensitive states. An accurate integration of CSC cellular states and EMT-related biomarkers with the currently available breast cancer molecular taxonomy may significantly improve our ability to make a priori decisions about whether patients belonging to HER2 subtypes differentially enriched with a “mesenchymal transition signature” (e.g., luminal/HER2 vs. basal/HER2) would distinctly benefit from trastuzumab-based therapy ab initio.
doi:10.4161/cc.23274
PMCID: PMC3575452  PMID: 23255137
basal-like; cancer stem cells; EMT; HER2; trastuzumab; breast cancer; reprogramming
22.  ALDH Activity Selectively Defines an Enhanced Tumor-Initiating Cell Population Relative to CD133 Expression in Human Pancreatic Adenocarcinoma 
PLoS ONE  2011;6(6):e20636.
Background
Multiple studies in recent years have identified highly tumorigenic populations of cells that drive tumor formation. These cancer stem cells (CSCs), or tumor-initiating cells (TICs), exhibit properties of normal stem cells and are associated with resistance to current therapies. As pancreatic adenocarcinoma is among the most resistant human cancers to chemo-radiation therapy, we sought to evaluate the presence of cell populations with tumor-initiating capacities in human pancreatic tumors. Understanding which pancreatic cancer cell populations possess tumor-initiating capabilities is critical to characterizing and understanding the biology of pancreatic CSCs towards therapeutic ends.
Methodology/Principal Findings
We have isolated populations of cells with high ALDH activity (ALDHhigh) and/or CD133 cell surface expression from human xenograft tumors established from multiple patient tumors with pancreatic adenocarcinoma (direct xenograft tumors) and from the pancreatic cancer cell line L3.6pl. Through fluorescent activated cell sorting (FACs)-mediated enrichment and depletion of selected pancreatic cancer cell populations, we sought to discriminate the relative tumorigenicity of cell populations that express the pancreatic CSC markers CD133 and aldehyde dehydrogenase (ALDH). ALDHhigh and ALDHlow cell populations were further examined for co-expression of CD44 and/or CD24. We demonstrate that unlike cell populations demonstrating low ALDH activity, as few as 100 cells enriched for high ALDH activity were capable of tumor formation, irrespective of CD133 expression. In direct xenograft tumors, the proportions of total tumor cells expressing ALDH and/or CD133 in xenograft tumors were unchanged through a minimum of two passages. We further demonstrate that ALDH expression among patients with pancreatic adenocarcinoma is heterogeneous, but the expression is constant in serial generations of individual direct xenograft tumors established from bulk human pancreatic tumors in NOD/SCID mice.
Conclusions/Significance
We conclude that, in contrast to some previous studies, cell populations enriched for high ALDH activity alone are sufficient for efficient tumor-initiation with enhanced tumorigenic potential relative to CD133+ and ALDHlow cell populations in some direct xenograft tumors. Although cell populations enriched for CD133 expression may alone possess tumorigenic potential, they are significantly less tumorigenic than ALDHhigh cell populations. ALDHhigh/CD44+/CD24+ or ALDHlow/CD44+/CD24+ phenotypes do not appear to significantly contribute to tumor formation at low numbers of inoculated tumor cells. ALDH expression broadly varies among patients with pancreatic adenocarcinoma and the apparent expression is recapitulated in serial generations of direct xenograft tumors in NOD/SCID. We have thus identified a distinct population of TICs that should lead to identification of novel targets for pancreatic cancer therapy.
doi:10.1371/journal.pone.0020636
PMCID: PMC3113804  PMID: 21695188
23.  PC3 prostate tumor-initiating cells with molecular profile FAM65Bhigh/MFI2low/LEF1low increase tumor angiogenesis 
Molecular Cancer  2010;9:319.
Background
Cancer stem-like cells are proposed to sustain solid tumors by virtue of their capacity for self-renewal and differentiation to cells that comprise the bulk of the tumor, and have been identified for a variety of cancers based on characteristic clonal morphologies and patterns of marker gene expression.
Methods
Single cell cloning and spheroid culture studies were used to identify a population of cancer stem-like cells in the androgen-independent human prostate cancer cell line PC3.
Results
We demonstrate that, under standard culture conditions, ~10% of PC3 cells form holoclones with cancer stem cell characteristics. These holoclones display high self-renewal capability in spheroid formation assays under low attachment and serum-free culture conditions, retain their holoclone morphology when passaged at high cell density, exhibit moderate drug resistance, and show high tumorigenicity in scid immunodeficient mice. PC3 holoclones readily form spheres, and PC3-derived spheres yield a high percentage of holoclones, further supporting their cancer stem cell-like nature. We identified one gene, FAM65B, whose expression is consistently up regulated in PC3 holoclones compared to paraclones, the major cell morphology in the parental PC3 cell population, and two genes, MFI2 and LEF1, that are consistently down regulated. This molecular profile, FAM65Bhigh/MFI2low/LEF1low, also characterizes spheres generated from parental PC3 cells. The PC3 holoclones did not show significant enriched expression of the putative prostate cancer stem cell markers CD44 and integrin α2β1. PC3 tumors seeded with holoclones showed dramatic down regulation of FAM65B and dramatic up regulation of MFI2 and LEF1, and unexpectedly, a marked increase in tumor vascularity compared to parental PC3 tumors, suggesting a role of cancer stem cells in tumor angiogenesis.
Conclusions
These findings support the proposal that PC3 tumors are sustained by a small number of tumor-initiating cells with stem-like characteristics, including strong self-renewal and pro-angiogenic capability and marked by the expression pattern FAM65Bhigh/MFI2low/LEF1low. These markers may serve as targets for therapies designed to eliminate cancer stem cell populations associated with aggressive, androgen-independent prostate tumors such as PC3.
doi:10.1186/1476-4598-9-319
PMCID: PMC3024252  PMID: 21190562
24.  Sonic Hedgehog Signaling Inhibition Provides Opportunities for Targeted Therapy by Sulforaphane in Regulating Pancreatic Cancer Stem Cell Self-Renewal 
PLoS ONE  2012;7(9):e46083.
Dysregulation of the sonic hedgehog (Shh) signaling pathway has been associated with cancer stem cells (CSC) and implicated in the initiation of pancreatic cancer. Pancreatic CSCs are rare tumor cells characterized by their ability to self-renew, and are responsible for tumor recurrence accompanied by resistance to current therapies. The lethality of these incurable, aggressive and invasive pancreatic tumors remains a daunting clinical challenge. Thus, the objective of this study was to investigate the role of Shh pathway in pancreatic cancer and to examine the molecular mechanisms by which sulforaphane (SFN), an active compound in cruciferous vegetables, inhibits self-renewal capacity of human pancreatic CSCs. Interestingly, we demonstrate here that Shh pathway is highly activated in pancreatic CSCs and plays important role in maintaining stemness by regulating the expression of stemness genes. Given the requirement for Hedgehog in pancreatic cancer, we investigated whether hedgehog blockade by SFN could target the stem cell population in pancreatic cancer. In an in vitro model, human pancreatic CSCs derived spheres were significantly inhibited on treatment with SFN, suggesting the clonogenic depletion of the CSCs. Interestingly, SFN inhibited the components of Shh pathway and Gli transcriptional activity. Interference of Shh-Gli signaling significantly blocked SFN-induced inhibitory effects demonstrating the requirement of an active pathway for the growth of pancreatic CSCs. SFN also inhibited downstream targets of Gli transcription by suppressing the expression of pluripotency maintaining factors (Nanog and Oct-4) as well as PDGFRα and Cyclin D1. Furthermore, SFN induced apoptosis by inhibition of BCL-2 and activation of caspases. Our data reveal the essential role of Shh-Gli signaling in controlling the characteristics of pancreatic CSCs. We propose that pancreatic cancer preventative effects of SFN may result from inhibition of the Shh pathway. Thus Sulforaphane potentially represents an inexpensive, safe and effective alternative for the management of pancreatic cancer.
doi:10.1371/journal.pone.0046083
PMCID: PMC3461003  PMID: 23029396
25.  MAGE-A3 is highly expressed in a cancer stem cell-like side population of bladder cancer cells 
Cancer stem cells (CSCs), which have the abilities of tumor-initiating, self-renewal and differentiation, are thought to cause post-therapeutic recurrence and the progression of cancer. However, CSCs are commonly resistant to current cancer therapies including chemotherapy and radiotherapy. In this study, we isolated cancer stem celllike side population (SP) cells from human bladder cancer cell line SW780 by a flow cytometry-based SP technique. SP cells were only about 3.6% of SW780 cells and showed higher expression of ATP-binding cassette sub-family G member 2 (ABCG2) and CD133. In vitro assay of tumor sphere growth as well as in vivo assay of xenograft transplantation confirmed the higher tumorigenicity of isolated SP cells. These data indicated that SP cells were enriched with CSCs of bladder cancer. Furthermore, we determined the expression of melanoma antigen family A, 3 (MAGEA3), one of the most studied cancer testis (CT) antigens, in these SP and main population (MP) cells derived from SW780 cells. SW780 SP cells representing CSCs of bladder cancer showed an up-regulated expression of MAGE-A3 and a positive coexpression of MAGE-A3 and CD133, indicating that MAGE-A3 was a novel CT antigen preferentially expressed in the CSCs of bladder cancer. In summary, our findings confirmed the existence of cancer stem cell-like SP cells in bladder cancer cells, and further indicated that MAGE-A3 is a novel CSC antigen and therefore may serve as an immunotherapeutic target for CSCs of bladder cancer.
PMCID: PMC4097252  PMID: 25031712
Melanoma antigen family A; 3 (MAGE-A3); bladder cancer; cancer stem cells; side population; cancertestis; immunotherapy

Results 1-25 (1218620)