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1.  Kinetic characterization of lactate dehydrogenase in normal and malignant human breast tissues 
Aerobic glycolysis rate is higher in breast cancer tissues than adjacent normal tissues which providethe ATP, lactate and anabolic precursors required for tumourgenesis and metastasis. Lactate dehydrogenase (LDH) is a critical enzyme during aerobic glycolysis as it is typically responsible for the production of lactate and regeneration of NAD+, which allows for the continued functioning of glycolysis even in the absence of oxygen. LDH has been found to be highly expressed in breast tumors. Enzyme kinetic characteristics is related to environmentinvolving the enzyme, and tumor microenvironment has distinct features relative to adjacent normal tissues, thus we hypothesized that LDH should have different kinetic characteristics in breast tumors compared to normal breast tissues.
LDH was partially purifiedfrom human breast tumors and normal tissues, which were obtained directly from operating room. TheMichaelis-Menten constant (Km), maximum velocity (Vmax), activation energy (Ea) and enzyme efficiency in breast tumors and normal tissueswere determined.
It was found that tumor LDH affinity in forward reaction was the same as normal LDH but Vmax of cancerous LDH was higher relative to normal LDH. In reverse reaction, affinity of tumor LDH for lactate and NAD+ was lower than normal LDH, also enzyme efficiency for lactate and NAD+ was higher in normal samples. The Ea of reverse reaction was higher in cancerous tissues.
It was concluded that thelow LDH affinity for lactate and NAD+ is a valuable tool for preserving lactate by cancer cells. We also conclude that increasing of LDH affinity may be a valid molecular target to abolish lactate dependent tumor growth and kinetic characteristics of LDH could be a novel diagnostic parameter for human breast cancer.
PMCID: PMC4334850
Breast cancer; Aerobic glycolysis; Lactate dehydrogenase; Enzyme kinetic
2.  The association between expressions of Ras and CD68 in the angiogenesis of breast cancers 
Cancer Cell International  2015;15(1):17.
Angiogenesis is a critical step of breast cancer metastasis. Oncogenic Ras promotes the remodeling of cancer microenviroment. Tumor-associated macrophages (TAMs) are a prominent inflammatory cell population emerging in the microenviroment and facilitating the angiogenesis and metastasis. In the present study, we tried to investigate the relationship between the expression of Ras and infiltration of TAM, both of which could further promote angiogenesis.
Expressions of Ras, CD68 and CD34 were assessed by immunohistochemistry. The infiltration of macrophages was evaluated by counting the number of CD68+ cells. Vessel endothelial cells were defined as CD34+ cells. Angiogenesis vascularity was defined by microvessel density (MVD) assay through counting the number of vessels per field counted in the area of highest vascular density. The Kaplan–Meier survival analysis was used to estimate the overall survival (OS). Macrophages were derived from monocytes in the presence of macrophage colony-stimulating-factor (MCSF). Breast cancer cells were treated with macrophage-conditioned medium (MCM) and tested the expressions of K-, H- and N-Ras by using realtime-PCR.
Ras positive status was correlated with ER, PR and Her-2 positivity, larger tumour size and lymph node metastasis, as well as higher TNM stages. A higher number of CD68+ cells was correlated with larger tumour size, higher TNM stages and Her-2 positivity. Both Ras positivity and infiltration of CD68+ macrophages correlated with poor OS. The number of CD68+ cells was positively correlated with the expression of Ras. Treatment with MCM did not up-regulate but repressed the expression of Ras. Both up-regulation of Ras and infiltration of TAMs correlated with increased MVD.
Expression of Ras and infiltration of TAM were positively correlated, and both participated in angiogenesis. Elevated Ras could be responsible for the infiltration of TAM.
PMCID: PMC4326448
Breast cancer; Ras; TAM; CD34; Angiogenesis
3.  Inhibition of the AKT pathway in cholangiocarcinoma by MK2206 reduces cellular viability via induction of apoptosis 
Cancer Cell International  2015;15(1):13.
Cholangiocarcinoma (CCA) is an aggressive disease with limited effective treatment options. The PI3K/Akt/mTOR pathway represents an attractive therapeutic target due to its frequent dysregulation in CCA. MK2206, an allosteric Akt inhibitor, has been shown to reduce cellular proliferation in other cancers. We hypothesized that MK2206 mediated inhibition of Akt would impact CCA cellular viability.
Study methods
Post treatment with MK2206 (0-2 μM), cellular viability was assessed in two human CCA cell lines—CCLP-1 and SG231—using an MTT assay. Lysates from the MK2206 treated CCA cells were then examined for apoptotic marker expression levels using Western blot analysis. Additionally, the effect on cellular proliferation of MK2206 treatment on survivin depleted cells was determined.
CCLP-1 and SG231 viability was significantly reduced at MK2206 concentrations of 0.5, 1, and 2 μM by approximately 44%, 53%, and 64% (CCLP-1; p = 0.01) and 32%, 32%, and 42% (SG231; p < 0.00005) respectively. Western analysis revealed a decrease in AKTSer473, while AKTThr308 expression was unchanged. In addition, cleaved PARP as well as survivin expression increased while pro-caspase 3 and 9 levels decreased with treatment. Depletion of survivin in CCLP-1 cells resulted in apoptosis as evidenced by increased cleaved PARP. In addition, survivin siRNA further enhanced the antitumor activity of MK2206.
This study demonstrates that by blocking phosphorylation of Akt at serine473, CCA cellular growth is reduced. The growth suppression appears to be mediated via apoptosis. Importantly, combination of survivin siRNA transfection and MK2206 treatment significantly decreased cell viability.
PMCID: PMC4324843
Cholangiocarcinoma; MK2206; PI3K/mTOR/AKT; Apoptosis
4.  Arf6 regulates EGF-induced internalization of E-cadherin in breast cancer cells 
Cancer Cell International  2015;15(1):11.
E-cadherin internalization facilitates dissolution of adherens junctions and promotes tumor cell epithelial-mesenchymal transition (EMT) and migration. Our previous results have shown that Arf6 exerts pro-migratory action in breast cancer cells after EGF stimulation. Despite the fact that EGF signaling stimulates EMT of breast cancer cells, the effect of Arf6 on internalization of E-cadherin of breast cancer cells under EGF treatment remains to be determined. Here, we showed that EGF dose-dependently stimulated E-cadherin internalization by MCF-7 cells with the maximal effect at 50 ng/ml. Meanwhile, EGF treatment markedly increased Arf6 activation. Arf6 was involved in complexes of E-cadherin, and more E-cadherin was pulled down with Arf6 when the activity of the latter was increased. Immunoblotting and immunofluorescence assays showed that transfection breast cancer cells with Arf6-T27N or Arf6 siRNA suppressed EGF-induced E-cadherin internalization. Taken together, our study demonstrated that Arf6 activation plays a potential role in EGF-induced E-cadherin internalization, providing new mechanism underlying the effect of Arf6 on promoting breast cancer cell metastasis.
Electronic supplementary material
The online version of this article (doi:10.1186/s12935-015-0159-3) contains supplementary material, which is available to authorized users.
PMCID: PMC4326200
EGF; Arf6; E-cadherin; Internalization; Breast cancer
5.  Inhibition of miR-191 contributes to radiation-resistance of two lung cancer cell lines by altering autophagy activity 
Cancer Cell International  2015;15(1):16.
Lung cancer is the leading cause of cancer-related morbidity and mortality all over the world. Surgery resection, radiotherapy, chemotherapy, immunotherapy and combined treatments have been discovered and well established for treatments. However, low survival rate of five years after clinical treatments mainly due to recurrence of stress-resistant cancer cells calls for better understanding and new ideas. Our project aimed to understand the forming process of stress resistant lung cancer cells after radiotherapy.
Two classic non-small cell lung cancer (NSCLC) cell lines A549 and H1299 initially were radiated with a 137Cs gamma-ray source with doses ranging from 0 to 12 Gy to generate radiation-resistant cancer cells. 8 Gy of radiation was regard as a standard dosage since it provides effective killing as well as good amount of survivals. The expression levels of autophagy-related proteins including Beclin-1, LC3-II and p62 were studied and measured by both western blot and quantitative real-time polymerase chain reaction (real-time RT-PCR).
Increased Beclin-1, LC3-II and decreased p62 have been observed in radiation-resistant cells indicating elevated autophagy level. Decreased miR-191 in radiation-resistant cells performed by Taqman qRT-PCR also has been seen. Two binding sites between Beclin-1 and miR-191 suggest potential association between.
It is reasonable to speculate that inhibition of miR-191 expression in lung cancer cells would contribute to the establishment of radiation-resistant cells via mediating cellular autophagy. Therefore, miR-191 is a potential target for therapy in treating radiation-resistant lung cancer.
PMCID: PMC4326374
Lung cancer; Autophagy; miR-191; Radiation-resistant
6.  Treatment with the PARP inhibitor, niraparib, sensitizes colorectal cancer cell lines to irinotecan regardless of MSI/MSS status 
Cancer Cell International  2015;15(1):14.
Cells with homologous recombination (HR) deficiency, most notably caused by mutations in the BRCA1 or BRCA2 genes, are sensitive to PARP inhibition. Microsatellite instability (MSI) accounts for 10-15% of colorectal cancer (CRC) and is hypothesized to lead to HR defects due to altered expression of Mre11, a protein required for double strand break (DSB) repair. Indeed, others have reported that PARP inhibition is efficacious in MSI CRC.
Here we examine the response to niraparib, a potent PARP-1/PARP-2 inhibitor currently under clinical evaluation, in MSI versus microsatellite stable (MSS) CRC cell lines in vitro and in vivo. We compiled a large panel of MSI and MSS CRC cell lines and evaluated the anti-proliferative activity of niraparib. In addition to testing single agent cytotoxic activity of niraparib, we also tested irinotecan (or SN-38, the active metabolite of irinotecan) activity alone and in combination with niraparib in vitro and in vivo.
In contrast to earlier reports, MSI CRC cell lines were not more sensitive to niraparib than MSS CRC cell lines¸ suggesting that the MSI phenotype does not sensitize CRC cell lines to PARP inhibition. Moreover, even the most sensitive MSI cell lines had niraparib EC50s greater than 10 fold higher than BRCA-deficient cell lines. However, MSI lines were more sensitive to SN-38 than MSS lines, consistent with previous findings. We have also demonstrated that combination of niraparib and irinotecan was more efficacious than either agent alone in both MSI and MSS cell lines both in vitro and in vivo, and that niraparib potentiates the effect of irinotecan regardless of MSI status.
Our results support the clinical evaluation of this combination in all CRC patients, regardless of MSI status.
PMCID: PMC4326439
7.  Variant RONΔ160 of the RON receptor tyrosine kinase promotes the growth and invasion in vitro and in vivo in gastric cancer cell lines 
Recepteur d’origine nantais (RON) is a receptor tyrosine kinase whose overexpression has been observed in human gastric cancers. This study aimed to determine whether overexpression of the variant RONΔ160 could induce tumorigenicity of gastric cancer cells in vitro or in vivo, and whether its specific small molecule inhibitor (Compound I) could inhibit the effect of RONΔ160.
We constructed human gastric cancer cell line MGC-803 that was stably transfected with a recombinant plasmid expressing RONΔ160, and the effect of RONΔ160 overexpression and macrophage-stimulating protein (MSP) activation on proliferation, migration and invasion abilities of MGC-803 cells were evaluated. Tumor-bearing mice with gastric cancer cells were used to analyze the effects of RONΔ160 overexpression and Compound I on implanted tumor growth.
In vitro, overexpression of RONΔ160 in MGC-803 cells resulted changes to their cell morphology, and promoted cell proliferation, migration and invasion. In addition, overexpression of RONΔ160 increased the proportion of cells in the S phase. The effect of RONΔ160 was significantly enhanced by induction of MSP inducing (p < 0.05). In vivo, RONΔ160 promoted the growth of MGC-803 cells in nude mice, including increased tumor size and weight, and lower tumor incubation period. The Compound I inhibited the tumorigenic abilities of RONΔ160 (p <0.05).
The results indicate that overexpression of the variant RONΔ160 altered the phenotype and tumorigenicity of MGC-803 cells. Its specific small molecule inhibitor could inhibit the effect of RONΔ160. Therefore, the variant RONΔ160 may become a potential therapeutic target for gastric cancer.
PMCID: PMC4326440
Gastric cancer; RON; RONΔ160; MSP; Tumorigenicity
8.  Antiproliferative and apoptosis-inducing activity of schisandrin B against human glioma cells 
Cancer Cell International  2015;15(1):12.
Malignant glioma is the most devastating and aggressive tumour in the brain and is characterised by high morbidity, high mortality and extremely poor prognosis. The main purpose of the present study was to investigate the effects of schisandrin B (Sch B) on glioma cells both in vitro and in vivo and to explore the possible anticancer mechanism underlying Sch B-induced apoptosis and cell cycle arrest.
The anti-proliferative ability of Sch B on glioma cells were assessed by MTT and clony formation assays. Flow cytometric analysis was used to detect cell cycle changes. Apoptosis was determined by Hoechst 33342 staining and annexin V/PI double-staining assays. The mitochondrial membrane potential was detected by Rhodamine 123 staining. The in vivo efficacy of Sch B was measured using a U87 xenograft model in nude mice. The expressions of the apoptosis-related and cell cycle-related proteins were analysed by western blot. Student’s t-test was used to compare differences between treated groups and their controls.
We found that Sch B inhibited growth in a dose- and time-dependent manner as assessed by MTT assay. In U87 and U251 cells, the number of clones was strongly suppressed by Sch B. Flow cytometric analysis revealed that Sch B induced cell cycle arrest in glioma cells at the G0/G1 phase. In addition, Sch B induced glioma cell apoptosis and reduced mitochondrial membrane potential (ΔΨm) in a dose-dependent manner. Mechanically, western blot analysis indicated that Sch B induced apoptosis by caspase-3, caspase-9, PARP, and Bcl-2 activation. Moreover, Sch B significantly inhibited tumour growth in vivo following the subcutaneous inoculation of U87 cells in athymic nude mice.
In summary, Sch B can reduce cell proliferation and induce apoptosis in glioma cells and has potential as a novel anti-tumour therapy to treat gliomas.
PMCID: PMC4326453
Glioma cells; Schisandrin B; Proliferation; Cell cycle; Apoptosis
9.  The multifaceted role of CD146/MCAM in the promotion of melanoma progression 
Human malignant melanoma is a common primary malignant cutaneous tumour derived from transformed epidermal melanocytes. Patients with melanoma have a high rate of mortality due to resistance to chemotherapeutic drugs, a major obstacle to a successful treatment. Several reports have suggested that CD146 plays an important role as a signalling molecule in human melanoma. This role includes CD146 as a participant in inflammation, differentiation, adhesion, tumourigenicity, metastasis, invasion and angiogenesis among other processes, which suggests that this molecule promotes the progression of human melanoma as a multifaceted regulator. In this article, we explore the effects and corresponding mechanisms with respect to the role of CD146/MUC18 in the promotion of human melanoma progression. Collectively, the studies indicated that targeting CD146, because it is a suitable marker of poor patient outcome, might be useful in the design of future strategies for the prevention and treatment of human melanoma.
PMCID: PMC4326486
CD146/MCAM; Melanoma; Structure; Mechanism; Metastasis; Angiogenesis
10.  Antihelminthic benzimidazoles potentiate navitoclax (ABT-263) activity by inducing Noxa-dependent apoptosis in non-small cell lung cancer (NSCLC) cell lines 
Evasion of apoptosis is a hallmark of cancer cells. One mechanism to deregulate the apoptotic pathway is by upregulation of the anti-apoptotic Bcl-2 family members. Navitoclax (ABT-263) is a Bcl-2/Bcl-xL inhibitor that restores the ability of cancer cells to undergo apoptosis.
In this study we performed a high-throughput screen with 640 FDA-approved drugs to identify potential therapeutic combinations with navitoclax in a non-small cell lung cancer (NSCLC) cell line.
Other than a panel of cancer compounds such as doxorubicin, camptothecin, and docetaxel, four antihelminthic compounds (benzimidazoles) potentiated navitoclax activity. Treatment with benzimidazoles led to induction of the pro-apoptotic protein Noxa at the mRNA and protein level. Noxa binds and antagonizes antiapoptotic protein Mcl-1. siRNA-mediated knock-down of Noxa completely rescued benzimidazole-potentiated navitoclax activity. In addition, inhibiting caspase 3 and 9 partially rescued benzimidazole-potentiated navitoclax activity.
We have identified compounds and mechanisms which potentiate navitoclax activity in lung cancer cell lines. Further validation of the benzimidazole-potentiated navitoclax effect in vivo is required to evaluate the potential for translating this observation into clinical benefit.
Electronic supplementary material
The online version of this article (doi:10.1186/s12935-014-0151-3) contains supplementary material, which is available to authorized users.
PMCID: PMC4326508
Benzimidazoles; Navitoclax; Caspase; Apoptosis
11.  EHMT2 inhibitor BIX-01294 induces apoptosis through PMAIP1-USP9X-MCL1 axis in human bladder cancer cells 
BIX-01294, an euchromatic histone-lysine N-methyltransferase 2 (EHMT2) inhibitor, has been reported to induce apoptosis in human neuroblastoma cells and inhibit the proliferation of bladder cancer cells. However, the definite mechanism of the apoptosis mediated by BIX-01294 in bladder cancer cells remains unclear. In the present study, we found that BIX-01294 induced caspase-dependent apoptosis in human bladder cancer cells. Moreover, our data show BIX-01294 stimulates endoplasmic reticulum stress (ER stress) and up-regulated expression of PMAIP1 through DDIT3 up-regulation. Furthermore, down-regulation of the deubiquitinase USP9X by BIX-01294 results in downstream reduction of MCL1 expression, leading to apoptosis eventually. Thus, our findings demonstrate PMAIP1-USP9X-MCL1 axis may contribute to BIX-01294-induced apoptosis in human bladder cancer cells.
PMCID: PMC4326523
Apoptosis; PMAIP1; MCL1; USP9X; DDIT3; ER stress; EHMT2; BIX-01294
12.  The role of individual caspases in cell death induction by taxanes in breast cancer cells 
In previous study we showed that caspase-2 plays the role of an apical caspase in cell death induction by taxanes in breast cancer cells. This study deals with the role of other caspases. We tested breast cancer cell lines SK-BR-3 (functional caspase-3) and MCF-7 (nonfunctional caspase-3).
Methods and results
Using western blot analysis we demonstrated the activation of initiator caspase-8 and -9 as well as executioner caspase-6 and -7 in both tested cell lines after application of taxanes (paclitaxel, SB-T-1216) at death-inducing concentrations. Caspase-3 activation was also found in SK-BR-3 cells. Employing specific siRNAs after taxane application, suppression of caspase-3 expression significantly increased the number of surviving SK-BR-3 cells. Inhibition of caspase-7 expression also increased the number of surviving SK-BR-3 and MCF-7 cells. On the other hand, suppression of caspase-8 and caspase-9 expression had no significant effect on cell survival. However, caspase-9 seemed to be involved in the activation of caspase-3 and caspase-7. Caspase-3 and caspase-7 appeared to activate mutually. Furthermore, we observed a significant decrease in mitochondrial membrane potential (flow cytometric analysis) and cytochrome c release (confocal microscopy, western blot after cell fractionation) from mitochondria in SK-BR-3 cells. No such changes were observed in MCF-7 cells after taxane treatment.
We conclude that the activation of apical caspase-2 results in the activation of caspase-3 and -7 without the involvement of mitochondria. Caspase-9 can be activated directly via caspase-2 or alternatively after cytochrome c release from mitochondria. Subsequently, caspase-9 activation can also lead to caspase-3 and -7 activations. Caspase-3 and caspase-7 activate mutually. It seems that there is also a parallel pathway involving mitochondria that can cooperate in taxane-induced cell death in breast cancer cells.
PMCID: PMC4329194
Taxanes; Breast cancer; Caspases; Cell death
13.  Galangin, a novel dietary flavonoid, attenuates metastatic feature via PKC/ERK signaling pathway in TPA-treated liver cancer HepG2 cells 
Galangin (3,5,7-trihydroxyflavone) is a flavonoid compound found in high concentration in lesser galangal. The objective of this study was to investigate the ability of galangin to inhibit 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced the invasion and metastasis of HepG2 liver cancer cells.
First, using a cell-matrix adhesion assay, immunofluorescence assay, transwell-chamber invasion/migration assay, and wound healing assay, we observed that galangin exerted an inhibitory effect on TPA-induced cell adhesion, morphology/actin cytoskeleton arrangement, invasion and migration. Furthermore, the results of gelatin zymography and reverse transcriptase polymerase chain reaction (RT-PCR) assays showed that galangin reduced the TPA-induced enzyme activity of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) in HepG2 cells; moreover, the messenger RNA level was downregulated. We also observed through a Western blotting assay that galangin strongly inhibited the TPA-induced protein expressions of protein kinase Cα (PKCα), protein kinase Cδ (PKCδ), phosphorylated extracellular signal-regulated kinase 1/2 (ERK1/2), the phospho-inhibitor of kappaBα (phospho-IκBα), c-Fos, c-Jun, and nuclear factor kappa B (NF-κB). Next, galangin dose-dependently inhibited the binding ability of NF-κB and activator protein 1 (AP-1) to MMP-2/MMP-9 promoters, respectively, resulting in the suppression of MMP-2/MMP-9 enzyme activity.
The results revealed that galangin effectively inhibited the TPA-induced invasion and migration of HepG2 cells through a protein kinase C/extracellular signal-regulated kinase (PKC/ERK) pathway. Thus, galangin may have widespread applications in clinical therapy as an anti-metastatic medicament.
PMCID: PMC4332891
Galangin; TPA; Invasion; Migration; PKC-α; ERK; MMP-2; MMP-9
14.  The effect of nilotinib plus arsenic trioxide on the proliferation and differentiation of primary leukemic cells from patients with chronic myoloid leukemia in blast crisis 
To determine the effects of arsenic trioxide (ATO) and nilotinib (AMN107, Tasigna) alone or in combination on the proliferation and differentiation of primary leukemic cells from patients with chronic myeloid leukemia in the blast crisis phase (CML-BC).
Cells were isolated from the bone marrow of CML-BC patients and were treated with 1 μM ATO and 5 nM nilotinib, either alone or in combination. Cell proliferation was evaluated using a MTT assay. Cell morphology and the content of hemoglobin were examined with Wright-Giemsa staining and benzidine staining, respectively. The expression of cell surface markers was determined using flow cytometric analysis. The levels of mRNA and protein were analyzed using RT-PCR and Western blotting, respectively.
ATO and nilotinib alone or in combination suppressed cell proliferation in a dose- and time-dependent pattern (P < 0.01 vs. control). Drug treatments promoted erythroid differentiation of CML-BC cells, with a decreased nuclei/cytoplasm ratio but increased hemoglobin content and glycophorin A (GPA) expression (P < 0.01 compared with control). In addition, macrophage and granulocyte lineage differentiation was also induced after drug treatment. The mRNA and protein levels of basic helix-loop-helix (bHLH) transcription factor T-cell acute lymphocytic leukemia protein 1 (TAL1) and B cell translocation gene 1 (BTG1) were both upregulated after 3 days of ATO and Nilotinib treatment.
Our findings indicated that ATO and nilotinib treatment alone or in combination greatly suppressed cell proliferation but promoted the differentiation of CML-BC cells towards multiple-lineages. Nilotinib alone preferentially induced erythroid differentiation while combined treatment with ATO preferentially induced macrophage and granulocyte lineage differentiation.
PMCID: PMC4334604
Arsenic trioxide; Nilotinib; AMN107; CML-BC; Proliferation; Differentiation
15.  Overview on the complexity of androgen receptor-targeted therapy for prostate cancer 
In the past decades, the field of prostate cancer (PCa) biology has developed exponentially and paralleled with that has been the growing interest in translation of laboratory findings into clinical practice. Based on overwhelming evidence of high impact research findings which support the underlying cause of insufficient drug efficacy in patients progressing on standard androgen deprivation therapy (ADT) is due to persistent activation of the androgen receptor (AR) signaling axis. Therefore, newer agents must be discovered especially because newer ADT such as abiraterone and enzalutamide are becoming ineffective due to rapid development of resistance to these agents. High-throughput technologies are generating massive and highly dimensional genetic variation data that has helped in developing a better understanding of the dynamic repertoire of AR and AR variants. Full length AR protein and its variants modulate a sophisticated regulatory system to orchestrate cellular responses. We partition this multicomponent review into subsections addressing the underlying mechanisms of resistance to recent therapeutics, positive and negative regulators of AR signaling cascade, and how SUMOylation modulates AR induced transcriptional activity. Experimentally verified findings obtained from cell culture and preclinical studies focusing on the potential of natural agents in inhibiting mRNA/protein levels of AR, nuclear accumulation and enhanced nuclear export of AR are also discussed. We also provide spotlight on molecular basis of enzalutamide resistance with an overview of the strategies opted to overcome such resistance. AR variants are comprehensively described and different mechanisms that regulate AR variant expression are also discussed. Reconceptualization of phenotype- and genotype-driven studies have convincingly revealed that drug induced resistance is a major stumbling block in standardization of therapy. Therefore, we summarize succinctly the knowledge of drug resistance especially to ADT and potential avenues to overcome such resistance for improving the treatment outcome of PCa patients.
PMCID: PMC4336517
Prostate cancer; Intracellular signaling; Apoptosis
16.  Understanding the colon cancer stem cells and perspectives on treatment 
An area of research that has been recently gaining attention is the relationship between cancer stem cell (CSC) biology and chemo-resistance in colon cancer patients. It is well recognized that tumor initiation, growth, invasion and metastasis are promoted by CSCs. An important reason for the widespread interest in the CSC model is that it can comprehensibly explain essential and poorly understood clinical events, such as therapy resistance, minimal residual disease, and tumor recurrence. This review discusses the recent advances in colon cancer stem cell research, the genes responsible for CSC chemoresistance, and new therapies against CSCs.
PMCID: PMC4328053
Cancer stem cells; Chemoresistance; Colon cancer
17.  Evaluating the evidence for targeting FOXO3a in breast cancer: a systematic review 
Tumour cells show greater dependency on glycolysis so providing a sufficient and rapid energy supply for fast growth. In many breast cancers, estrogen, progesterone and epidermal growth factor receptor-positive cells proliferate in response to growth factors and growth factor antagonists are a mainstay of treatment. However, triple negative breast cancer (TNBC) cells lack receptor expression, are frequently more aggressive and are resistant to growth factor inhibition. Downstream of growth factor receptors, signal transduction proceeds via phosphatidylinositol 3-kinase (PI3k), Akt and FOXO3a inhibition, the latter being partly responsible for coordinated increases in glycolysis and apoptosis resistance. FOXO3a may be an attractive therapeutic target for TNBC. Therefore we have undertaken a systematic review of FOXO3a as a target for breast cancer therapeutics.
Articles from NCBI were retrieved systematically when reporting primary data about FOXO3a expression in breast cancer cells after cytotoxic drug treatment.
Increased FOXO3a expression is common following cytotoxic drug treatment and is associated with apoptosis and cell cycle arrest. There is some evidence that metabolic enzyme expression is also altered and that this effect is also elicited in TNBC cells. FOXO3a expression serves as a positive prognostic marker, especially in estrogen (ER) receptor positive cells.
FOXO3a is upregulated by a number of receptor-dependent and -independent anti-cancer drugs and associates with apoptosis. The identification of microRNA that regulate FOXO3a directly suggest that it offers a tangible therapeutic target that merits wider evaluation.
PMCID: PMC4325954
Triple negative breast cancer; Phosphatidylinositol 3-kinase; Metabolism; Glycolysis; Oxidative stress; Apoptosis
18.  Clinical and laboratory features of seven patients with acute myeloid leukemia (AML)-M2/M3 and elevated myeloblasts and abnormal promyelocytes 
Cancer Cell International  2014;14(1):111.
There is limited information on a special subtype of Acute myeloid leukemia (AML) characterized by >20% myeloblasts and >20% abnormal promyelocytes in bone marrow and peripheral blood.
The objective of the present investigation was to explore the clinical and laboratory features of seven patients with AML-M2/M3.
We retrospectively assessed cell morphology, cytochemistry, immunophenotype, cytogenetics, and clinical features of seven patients with this rare subtype of AML.
All seven cases had thrombocytopenia, coagulation abnormalities, >20% myeloblasts and abnormal promyelocytes. The PML/RARα fusion gene was present in six patients and two patients presented a mixed PML/RARα and AML1/ETO genotype. Five cases achieved CR and two cases did not achieve remission and one case transform into AML-M2 after CR1.
The clinical and laboratory features of seven patients with AML-M2/M3 are demonstrated in the present study, providing information on the FAB sub-classification.
PMCID: PMC4325959
Acute myeloid leukemia (AML); AML-M2/M3 subtype; Mixed phenotype; Myeloblasts; Abnormal promyelocytes
19.  Changes of T-lymphocyte subpopulation and differential expression pattern of the T-bet and GATA-3 genes in diffuse large B-cell lymphoma patients after chemotherapy 
Background and objective
T cell-mediated immunity plays an important role in enhancing antitumor response.This study aimed to investigate the changes in the T-lymphocyte subpopulation and to characterize the differential expression pattern of corresponding regulatory genes in peripheral blood mononuclear cells (PBMCs) from diffuse large B cell lymphoma (DLBCL) patients before and after chemotherapy.
A total of 56 DLBCL patients were recruited for analysis of T-cell subset distribution in the peripheral blood using flow cytometry; serum interferon (IFN)-γ and interleukin (IL)-4 levels using enzyme-linked immunosorbent assays; and early growth response protein 1 (EGR-1), T-bet, GATA-binding protein 3 (GATA-3), and transforming growth factor (TGF)-β mRNA levels using quantitative reverse-transcription polymerase chain reaction. Twenty-six healthy subjects served as controls.
The percentage of CD3+CD4+T lymphocytes in peripheral blood from DLBCL patients was significantly decreased, whereas the percentages of CD3+CD8+T and CD4+CD25+T cells were significantly increased compared to those in controls (p < 0.05). Serum levels of IFN-γ and IL-4 were also significantly lower in DLBCL patients than those in controls (p < 0.05), and the levels of EGR-1, T-bet, and GATA-3 mRNA in PBMCs were lower (2.69 ± 1.48, 9.43 ± 2.14, and 20.83 ± 9.05 fold, respectively) in DLBCL patients than those in controls. Furthermore, there was a positive association between the levels of EGR-1 and T-bet mRNA (p = 0.001). However, the level of TGF-β mRNA was significantly increased in DLBCL patients, which was inversely associated with the T-bet mRNA level (p = 0.008), but positively associated with the percentage of T regulatory cells in PBMCs (p = 0.011). After three cycles of chemotherapy, the distribution of T-lymphocyte subsets in DLBCL patients were changed, and the levels of EGR-1, T-bet, and GATA-3 mRNA were significantly increased (p < 0.05) compared to those before chemotherapy.
These results demonstrate the changes in T-lymphocyte subpopulations and the altered expression 34 pattern of the corresponding regulatory genes in PBMCs from DLBCL patients after chemotherapy, which are associated with the response of patients to treatment. The preferential expression of the T-bet gene after chemotherapy was closely correlated with the increased expression of the EGR-1 gene and decreased expression of the TGF-β gene.
PMCID: PMC4336681
Diffuse large B cell lymphoma; Th1/Th2; T-bet; GATA-3; Immunoregulation
20.  Differential drug resistance acquisition to doxorubicin and paclitaxel in breast cancer cells 
Cancer Cell International  2014;14(1):538.
Several signal transduction pathways have been reported being involved in the acquisition of P-glycoprotein (P-gp) mediated multi-drug resistance (MDR) upon exposure to anti-cancer drugs, whereas there is evidence indicating that the expression and activity of P-gp were not equally or even reversely modulated by different drugs.
To further illustrate this drug-specific effect, possible mechanisms that enable breast cancer cells MCF-7 to acquire MDR to either paclitaxel (PTX) or doxorubicin (DOX) were investigated in a time-dependent manner.
The results suggested that at least two pathways participated in this process. One was the short and transient activation of NF-κB, the second one was the relatively prolonged induction of PXR. Both PXR and NF-κB pathways took part in the PTX drug resistance acquisition, whereas DOX did not exert a significant effect on the PXR-mediated induction of P-gp. Furthermore, the property of NF-κB activation shared by DOX and PTX was not identical. An attempt made in the present study demonstrated that the acquired resistance to DOX was via or partially via NF-κB activation but not its upstream receptor TLR4, while PTX can induce the drug resistance via TLR4-NF-κB pathway.
To our knowledge, this report is among the first to directly compare the time dependence of NF-κB and PXR pathways. The current study provides useful insight into the distinct ability of DOX and PTX to induce P-gp mediated MDR in breast cancer. Different strategies may be required to circumvent MDR in the presence of different anti-cancer drugs.
Electronic supplementary material
The online version of this article (doi:10.1186/s12935-014-0142-4) contains supplementary material, which is available to authorized users.
PMCID: PMC4279688  PMID: 25550688
Multi-drug Resistance Acquisition (MDR); P-glycoprotein (P-gp); Drug-specific; Doxorubicin (DOX); Paclitaxel (PTX)
21.  A novel GFP nude rat model to investigate tumor-stroma interactions 
Cancer Cell International  2014;14(1):541.
A key strategy for the study of the tumor microenvironment is to implant human tumor cells in an immunodeficient rodent strain ubiquitously expressing a fluorescent marker. Here, a novel nude rat expressing a green fluorescent protein (GFP) transgene was established and engrafted with primary human tumor tissue in order to separate tumor from stromal cell populations for subsequent molecular analysis.
SD-TG (GFP) 2BalRrrc transgenic rats were crossed with HsdHan™: rnu/rnu Rowett nude rats to develop a GFP expressing immunocompromised rat. PCR and flow cytometry were used to follow the GFP genotype and phenotype in newborns. After three to four generations, animals were implanted with 4 T1 dsRed murine breast cancer cells or primary human glioblastoma (GBM) biopsies to generate xenografts for subsequent separation by fluorescence-activated cell sorting (FACS).
Fluorecence microscopy and reverse transcription-PCR demonstrated that GFP, under the control of the human ubiquitin C promoter, was stably maintained and expressed in diverse organs over several generations. Immunophenotyping of blood samples by flow cytometry confirmed that the immunodeficient features of the parental rat strain, HsdHan™: rnu/rnu, were retained in the GFP nude rat. Both the murine cell line and human GBM biopsies engrafted, and stromal cell populations were isolated from dissociated xenografts by FACS to > 95% purity.
A GFP transgene was stably introduced into a nude rat background in which human and murine cancer cells successfully engrafted. This animal strain provides a novel in vivo system for detailed cellular and molecular characterization of tumor-stroma interactions.
PMCID: PMC4319225  PMID: 25663822
Xenograft; Tumor-stroma interaction; Glioblastoma; Breast cancer; Tumor biology
22.  Patterns of cancer cell sphere formation in primary cultures of human oral tongue squamous cell carcinoma and neck nodes 
Cancer Cell International  2014;14(1):542.
Recently a sub-population of cells with stem cell characteristics, reported to be associated with initiation, growth, spread and recurrence, has been identified in several solid tumors including oral tongue squamous cell carcinoma (OTSCC). The aim of our pilot study was to isolate CD44+ cancer stem cells from primary cultures of OTSCC and neck node Level I (node-I) biopsies, grow cell spheres and observe their characteristics in primary cultures. Parallel cultures of hyperplastic lesions of tongue (non-cancer) were set up as a control. Immunohistochemistry was used to detect CD44/CD24 expression and magnetic activated cell sorting to isolate CD44+ cell populations followed by primary cell culturing. Both OTSCC and node-I biopsies produced floating spheres in suspension, however those grown in hyperplastic and node-I primary cultures did not exhibit self-renewal properties. Lymph node metastatic OTSCC, express higher CD44/CD24 levels, produce cancer cell spheres in larger number and rapidly (24 hours) compared to node negative OTSCC (1 week) and non-cancer specimens (3 weeks). In addition, metastatic OTSCC have the capacity for proliferation for up to three generations in primary culture. This in vitro system will be used to study cancer stem cell behavior, therapeutic drug screening and optimization of radiation dose for elimination of resistant cancer cells.
Electronic supplementary material
The online version of this article (doi:10.1186/s12935-014-0143-3) contains supplementary material, which is available to authorized users.
PMCID: PMC4326435
Oral tongue squamous cell carcinoma; Lymph node metastasis; Primary culture; Cancer cell sphere; Cancer stem cells; in vitro assay
23.  Estrogen mediated expression of nucleophosmin 1 in human endometrial carcinoma clinical stages through estrogen receptor-α signaling 
Cancer Cell International  2014;14(1):540.
Endometrial carcinoma is one of the most common gynecologic malignancies. Estrogen plays a critical role in its pathogenesis, but the underlying mechanism is not clear. Nucleophosmin 1 (NPM1), a multifunctional protein involved in many cellular activities, has been implicated in the tumorigenesis processes. However, the role of NPM1 in endometrial carcinogenesis remains to be elucidated. The present study was aimed to elucidate the role of NPM1 in different clinical stages of human endometrial carcinoma and the underlying mechanism of NPM1 action.
The distribution and expression of NPM1 in normal endometrium, FIGO stages I to IV endometrial carcinoma tissues was analyzed using immunohistochemistry, RT-qPCR and Western blotting. The association between NPM1 expression and estrogen and estrogen receptor signaling was investigated in primary-cultured FIGO stage I endometrial adenocarcinoma cells.
A strong positive correlation between NPM1 level and the clinical stage and histological grade of endometrial carcinomas was observed. Expression of NPM1 was up-regulated by estrogen in primary-cultured human endometrial adenocarcinoma cells. Furthermore, estrogen increased NPM1 level via estrogen receptor-α (ERα) signaling, nor estrogen receptor-β signaling.
Expression of NPM1 was gradually increased with the increase of clinical stages of endometrial carcinomas. Overexpression of NPM1 may play a role in the effects of estrogen on the malignant progression of endometrioid adenocarcinoma via ERα signaling. These findings may extend our understanding of the oncogenesis of steroid hormone-related cancers and have significance for the diagnosis and treatment of this carcinoma.
PMCID: PMC4319226  PMID: 25663821
Endometrial carcinomas; Nucleophosmin 1(NPM1); Estrogen; Estrogen receptor-α(ERα)
24.  Altered expression of T cell Immunoglobulin-Mucin (Tim) molecules in peripheral blood mononuclear cells in aplastic anemia 
Cancer Cell International  2014;14(1):144.
To evaluate the balance between T-cell immunoglobulin and mucin domain (Tim) molecules(Tim)-1 and Tim-3 in patients with aplastic anemia (AA), plasma IFN-γ and IL-4 levels were measured in patients with active AA (n = 41), AA in remission (n = 29) and in healthy subjects (n = 40) by enzyme linked immunosorbent assay (ELISA). Using real-time quantitative polymerase chain reaction (RT-PCR), the mRNA expression of IFN-γ, IL-4, Tim-1 and Tim-3 were studied in all subjects. The results showed that the expression of Tim-3 in newly diagnosed patients was significantly deceased, compared with the controls. Meanwhile, Tim-1 mRNA expression in the active AA group was not significantly reduced, which resulted in a declined ratio of Tim-3/Tim-1 in patients with active disease. During the remission stages, the levels of these transcription factors were comparable with those observed in the healthy controls. These findings are the first data on the expression of the Tim-1 and Tim-3 molecules in AA. The reduced levels of Tim-3/Tim-1 in PBMCs during the active stages of disease suggest that they may play a possible role in the pathogenesis and course of AA.
PMCID: PMC4278261  PMID: 25548541
Aplastic anemia; T-cell immunoglobulin and mucin domain; IFN-γ; Interleukin 4; Cytokines; RT-PCR
25.  Induction of H2AX phosphorylation in tumor cells by gossypol acetic acid is mediated by phosphatidylinositol 3-kinase (PI3K) family 
Cancer Cell International  2014;14(1):141.
H2AX is phosphorylated (γH2AX) by members of the phosphatidylinositol 3-kinase (PI3K) family, including Ataxia telangiectasia-mutated (ATM), ATM- and Rad3-related (ATR) and DNA-PK in response to DNA damage. Our study shows that gossypol acetic acid (GAA) alone can induce γH2AX in Human mucoepidermoid carcinoma cell line (MEC-1) in vitro. Thus, we further examined the possible mechanisms of GAA to induce γH2AX in tumor cells.
Materials and methods
The PI3K inhibitors caffeine and wortmannin were used in an effort to identify the kinase(s) responsible for GAA -induced γH2AX in MEC-1 cells. DNA dependent protein kinase (DNA-PK) - proficient and –deficient cells, human glioma cell lines M059K and M059J, were also used to evaluate the kinases responsible for GAA induced H2AX phosphorylation. γH2AX expression was detected by immunofluorescent microscopy. Flow cytometry assay was used to assay γH2AX and cell cycle.
GAA induced H2AX phosphorylation in a cell cycle-dependent manner and a significant G0/G1 phase arrest in MEC-1 cells was shown. Caffeine and wortmannin significantly inhibited GAA-induced H2AX phosphorylation in MEC-1 cells. GAA induced H2AX phosphorylation in M059K, but not in M059J. Taken together, these data suggested that GAA treatment alone could induce H2AX phosphorylation in a cell cycle dependent manner in MEC-1 and M059K, but not in M059J cells. A significant G0/G1 phase arrest was shown in MEC-1.
The member of PI3K family, DNA-PK, ATM and ATR are involved in the H2AX phosphorylation of MEC-1 cells.
PMCID: PMC4272777  PMID: 25530717
Gossypol acetic acid; H2AX phosphorylation; DNA-PK; ATM; ATR

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