The oncogene RAS is known to induce genomic instability, leading to cancer development; the underlying mechanism, however, remains poorly understood. To better understand how RAS functions, we measured the activity of the functionally related genes Aurora-A and BRCA2 in ovarian cancer cell lines and tumor samples containing RAS mutations. We found that Aurora-A and BRCA2 inversely controlled RAS-associated genomic instability and ovarian tumorigenesis through regulation of cytokinesis and polyploidization. Over-expression of mutated RAS ablated BRCA2 expresson but induced Aurora-A accumulation at the midbody, leading to abnormal cytokinesis and ultimately chromosomal instability via polyploidy in cancer cells. RAS regulates the expression of Aurora-A and BRCA2 through dysregulated protein expression of farnesyl protein transferase β (FTβ and insulin-like growth factor binding protein 3 (IGFBP-3). Our results suggest that the imbalance in expression of Aurora-A and BRCA2 regulates RAS-induced genomic instability and tumorigensis.
RAS; Aurora-A; BRCA2; Polyploid Cancer Cells; Cytokinesis; Genomic instability
Bone marrow is generally considered the main source of erythroid cells. Here we report that a single hypoxia-mimic chemical, CoCl2, can the size of fibroblasts and cancer cells and lead to formation of polyploidy giant cells (PGCs) or polyploidy giant cancer cells (PGCCs), activation of stem cell marker expression, increased growth of normal and cancer spheroid, and lead to differentiation of the fibroblasts and epithelial cells toward erythroid lineage expressing hemoglobins both in vitro and in vivo. Immunohistochemical examination demonstrated that these cells are predominantly made of embryonic hemoglobins, with various levels of fetal and adult hemoglobins. Ectopic expression of c-Myc induced the generation of nucleated erythoid cells expressing variable levels of embryonic and fetal hemoglobins. Generation of these erythroid cells can be also observed via histological examination of other cancer cell lines and human tumor samples. These data suggest that normal and solid cancer cells can directly generate erythroid cells to obtain oxygen in response to hypoxia and may explain the ineffectiveness of conventional anti-angiogenic therapies for cancer, which are directed at endothelium-dependent vessels, and offer new targets for intervention.
Solid tumor cells; Erythroid cells; Hypoxia; Cobalt chloride; c-Myc
The majority of patients with epithelial ovarian cancer achieved a complete clinical remission with normal CA-125 will still relapse and die from their disease. The present study was to determine whether CA-125 levels before, during and after primary treatment provided prognostic information for both Type I and Type II ovarian cancer.
In this retrospective study, we identified 410 epithelial ovarian cancer patients who had achieved a CCR between 1984 and 2011. A Cox proportional hazards model and log-rank test were used to assess associations between the nadir CA-125, histotype, and prognosis.
The baseline serum CA-125 concentration was higher in patients with type II ovarian cancer than in those with type I (p < 0.001). The nadir CA-125 was an independent predictor of PFS (p < 0.001) and OS (p = 0.035) duration. The PFS and OS durations were 21.7 and 79.4 months in patients with CA-125 ≤ 10 U/ml and 13.6 and 64.6 months in those with 11-35 U/ml (p = 0.01 and 0.002, respectively). Histotype was an independent predictor of PFS (p = 0.041): the PFS and OS durations of type I patients were longer than those in type II (p < 0.001 and < 0.001, respectively).
The nadir CA-125 and the histotype are predictive of PFS and OS duration in ovarian cancers experienced a CCR. PFS and OS durations were shorter in patients with CA-125 levels of 11-35 U/ml and type II disease than in those with ≤ 10 U/ml and type I.
ovarian cancer; CA-125; prognosis factors; tumor marker; pathological type
Tumor microenvironment plays a major role in cancer development. Understanding how the stroma affects epithelial transformation will provide a basis for new preventive strategies. Recent evidences suggest that oxidative stress in stroma may play a role in cancer progression and loss of p53 function in the stromal cells were associated with poor prognosis and high tumor recurrence. However, the underlying mechanisms remain poorly understood. Here, we investigated the role of p53 loss in fibroblasts on epithelial transformation and the mechanistic involvement of reactive species. Using 3D-organotypic culture and other assays, we report that the stroma containing p53-deficient fibroblasts could transform the non-tumorigenic epithelial cells of oral and ovarian tissues origins to become invasive through reactive nitrogen species (RNS)-mediated release of cytokine ICAM1. The p53-deficient fibroblasts have increased RNS production and accumulation of oxidative DNA damage products associated with specific up-regulation of endothelial nitric oxide synthase (eNOS). Suppression of RNS production by siRNA of eNOS or antioxidant NAC reduced ICAM1 expression and prevented the stroma-mediated epithelial invasion. Our study uncovers the novel mechanism by which redox alteration associated with loss of p53 in stromal fibroblasts function as a key inducer of epithelial transformation and invasion via RNS-mediated-ICAM1 signaling. Thus, modulation of the redox signaling in microenvironment may serve as a new approach to prevent epithelial transformation and suppress cancer invasion.
fibroblast; ICAM1; Invasion; RNS; p53; eNOS
Immunosuppression associated with infections of nematode parasites has been documented. Cysteine protease inhibitor (CPI) released by the nematode parasites is identified as one of the major modulators of host immune response. In this report, we demonstrated that the recombinant CPI protein of Ascaris lumbricoides (Al-CPI) strongly inhibited the activities of cathepsin L, C, S, and showed weaker effect to cathepsin B. Crystal structure of Al-CPI was determined to 2.1 Å resolution. Two segments of Al-CPI, loop 1 and loop 2, were proposed as the key structure motifs responsible for Al-CPI binding with proteases and its inhibitory activity. Mutations at loop 1 and loop 2 abrogated the protease inhibition activity to various extents. These results provide the molecular insight into the interaction between the nematode parasite and its host and will facilitate the development of anthelmintic agents or design of anti-autoimmune disease drugs.
Early serous carcinoma in fallopian tube or serous tubal intraepithelial carcinoma (STIC), an early lesion limited to the epithelium of the fallopian tube and firstly identified from specimen obtained by prophylactic salpingo-oophorectomy, has provided insight into pelvic high grade serous carcinoma (HGSC). Increasing evidence indicates that STIC is a likely precursor for HGSC and several studies have focused on this lesion and its clinical significance. This review addresses recent advances in recognizing STIC and its correlation with HGSC and ovarian carcinogenesis. It also describes evidence regarding the fallopian tube as a source of some HGSCs, the protocol for optimizing histological evaluation of the tubes, the spectrum of tubal lesions from benign to noninvasive carcinoma, changes in diagnostic criteria from purely morphologic characteristics to a combination of morphologic features and molecular biomarkers, and new studies about potential biomarkers. However, the direct evidence regarding STIC as the precursor of HGSC is still tantalizing due to other possibilities that may also explain the origin of pelvic HGSC. Further molecular genetic studies are required to address this important question.
Serous tubal intraepithelial carcinoma; fallopian tube; high grade serous carcinoma; ovarian cancer; carcinogenesis
Integrated genomic analyses revealed a miRNA-regulatory network, which further defined a robust integrated mesenchymal subtype associated with poor overall survival in 459 cases of serous ovarian cancer (OvCa) from The Cancer Genome Atlas and 560 cases from independent cohorts. Eight key miRNAs, including miR-506, miR-141 and miR-200a, were predicted to regulate 89% of the targets in this network. Follow-up functional experiments illustrate that miR-506 augmented E-cadherin expression, inhibited cell migration and invasion, and prevented TGFβ-induced epithelial-mesenchymal transition (EMT) by targeting SNAI2, a transcriptional repressor of E-cadherin. In human OvCa, miR-506 expression was correlated with decreased SNAI2 and VIM, elevated E-cadherin, and beneficial prognosis. Nanoparticle delivery of miR-506 in orthotopic OvCa mouse models led to E-cadherin induction and reduced tumor growth.
The degree of differentiation in human cancers generally reflects the degree of malignancy, with the most undifferentiated cancer being also the highest grade and the most aggressive. High-grade serous ovarian carcinomas (HGSOC) are poorly differentiated and fast-growing malignancies. The molecular mechanisms underlying the poor differentiation of HGSOC has not been completely characterized. Evidence suggests that miRNA, miR are dysregulated in HGSOC. Therefore, we focused on those miRNAs that are relevant to tumor differentiation. Expression profiling of miRNAs in HGSOC, indicated miR-106a and its family members were significantly upregulated. Upregulation of miR-106a was further validated by real-time reverse transcriptase PCR (qRT-PCR) and miRNA in situ hybridization in a large cohort of HGSOC specimens. Overexpression of miR-106a in benign and malignant ovarian cells significantly increased the cellular proliferation rate and expanded the side-population fraction. In particular, SKOV3 cells with miR-106a overexpression had significantly higher tumor initial/stem cell population (CD24- and CD133-positive cells) than control SKOV3 cells. Among many miR-106a predicated target genes, p130 (RBL2), an retinoblastoma (Rb) tumor suppressor family member, was not only confirmed as a specific target of miR-106a but also related to tumor growth and differentiation. The importance of mir-106a and RBL2 was further demonstrated in vivo, in which, SKOV3 cells overexpressing miR-106a formed poorly differentiated carcinomas and had reduced RBL2 levels. To our knowledge, this is the first study of miR-106a mediating proliferation and tumor differentiation in HGSOC.
The current study suggests that the RB tumor suppressor pathway is a critical regulator of growth and differentiation in HGSOC.
Cancer is not only composed malignant epithelial component but also stromal components such as fibroblasts, endothelial cells, and inflammatory cells, by which an appropriate tumor microenvironment (TME) is formed to promote tumorigenesis, progression, and metastasis. As the most abundant component in the TME, cancer-associated fibroblasts (CAFs) are involved in multifaceted mechanistic details including remodeling the extracellular matrix, suppressing immune responses, and secreting growth factors and cytokines that mediate signaling pathways to extensively affect tumor cell growth and invasiveness, differentiation, angiogenesis, and chronic inflammatory milieu. Today, more and more therapeutic strategies are purposefully designed to target the TME as well as tumor cells. This review will focus on the role of CAFs in tumor development and the novel strategies to target this component to inhibit the tumor growth.
Tumor microenvironment; Cancer-associated fibroblasts; Extracellular matrix; Cancer signaling; Cancer therapy
Titanium is widely used in biomedical materials, particularly in dental implants, because of its excellent biocompatibility and mechanical characteristics. However, titanium implant failures still remain in some cases, varying with implantation sites and patients. Improving its overall performance is a major focus of dental implant research. Equal-channel angular pressing (ECAP) can result in ultrafine-grained titanium with superior mechanical properties and better biocompatibility, which significantly benefits dental implants, and without any harmful alloying elements. Lanthanum (La) can inhibit the acidogenicity of dental plaque and La-containing hydroxyapatite (La-HA) possesses a series of attractive properties, in contrast to La-free HA. Micro-arc oxidation (MAO) is a promising technology that can produce porous and firmly adherent hydroxyapatite (HA) coatings on titanium substrates. Therefore, we hypothesize that porous La-containing hydroxyapatite coatings with different La content (0.89%, 1.3% and 1.79%) can be prepared on ultrafine-grained (~200–400 nm) titanium by ECAP and MAO in electrolytic solution containing 0.2 mol/L calcium acetate, 0.02 mol/L β-glycerol phosphate disodium salt pentahydrate (β-GP), and lanthanum nitrate with different concentrations to further improve the overall performance of titanium, which are expected to have great potential in medical applications as a dental implant.
Dental Implants; Dentistry; Hydroxyapatites; Titanium
We report the design, synthesis, and biological evaluation
new series of largazole analogues in which a 4-methylthiazoline moiety
was replaced with a triazole and tetrazole ring, respectively. Compound 7 bearing a tetrazole ring was identified to show much better
selectivity for HDAC1 over HDAC9 than largazole (10-fold). This work
could serve as a foundation for further exploration of selective HDAC
inhibitors using a largazole molecular scaffold.
HDAC inhibitor; peptides; macrocycles; largazole; click chemistry
Paclitaxel is commonly used to treat multiple human malignancies, but its mechanism of action is still poorly defined. Human ovarian cancer SKOV3 cells (parental SKOV3) were treated with paclitaxel (1 μM) for 2 days, and the morphologic changes in the cells were monitored for more than 4 months. Parental SKOV3 underwent a markedly morphologic transition from the epithelial to fibroblast-like phenotype following treatment with paclitaxel; the resulting cells were designated as SKOV3-P. The SKOV3-P cells’ proliferative ability was assessed via a 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay. The molecular characteristics of these cells were assessed via immunocytochemical staining and Western blot analysis. Their invasiveness and tumor formation ability was evaluated via wound-scratch and colony formation assays. The tumorigenicity of SKOV3-P cells was assessed in vivo after subcutaneous injection of tumor cells between injections of parental and paclitaxel-treated cells in nude mice. SKOV3-P cells have decreased the proliferation and invasion ability, decreased colony-forming ability when cultured in Matrigel and lost their tumor formation as compared with parental SKOV3 cells when injected in nude mice. SKOV3-P cells have decreased expression of E-cadherin, cytokeratin, Snail, PI3K, and P-Akt-Ser473, and increased expression of fibronectin, vimentin, Slug, P27, and PTEN. These results demonstrated that paclitaxel can inhibit tumor growth by inducing ovarian cancer epithelial cells toward a benign fibroblast-like phenotype through dysregulation of previously known pathways involved in the regulation of epithelial to mesenchymal transition (EMT), which may represent a novel mechanism for paclitaxel-induced tumor suppression.
Ovarian Cancer; Paclitaxel; Epithelial to Mesenchymal Transition; Fibronectin
As a putative marker for cancer stem cells in human malignant tumors, including ovarian cancer, CD133 expression may define a tumor-initiating subpopulation of cells and is associated with the clinical outcome of patients. However, at this time its clinical significance in ovarian cancer remains uncertain. The aim of this study was to clarify the clinical role of CD133 expression in human ovarian cancer. Immunohistochemical staining of CD133 expression was performed in 400 ovarian carcinoma samples using tissue microarray. The associations among CD133 expression and clinical factors (diagnosis, tumor grade, cancer stage, and clinical response to chemotherapy), overall survival and disease-free survival time were analyzed. CD133 expression was found in 31% of ovarian carcinoma samples. Fisher’s exact test and one-way analysis of variance suggested that CD133 expression was associated with high-grade serous carcinoma (P = 0.035), late-stage disease (P < 0.001), ascites level (P = 0.010), and non-response to chemotherapy (P = 0.023). CD133 expression was also associated with shorter overall survival time (P = 0.007) and shorter disease-free survival time (P < 0.001) by log-rank test. Moreover, CD133 expression was an independent predictor of shorter disease-free survival time in an unconditional logistic regression analysis with multiple covariates (P = 0.024). Our results thus show that CD133 expression is a predictor of poor clinical outcome for patients with ovarian cancer, supporting the proposed link between CD133 and cancer stem cells.
CD133; immunohistochemistry; ovarian cancer; prognosis
Polyploid giant cancer cells (PGCCs) are a morphologically distinct subgroup of human tumor cells with increased nuclear size or multiple nuclei, but they are generally considered unimportant because they are presumed to be nondividing and thus nonviable. We have recently shown that these large cancer cells are not only viable but also can divide asymmetrically and yield progeny cancer cells with cancer stem-like properties via budding division. To further understand the molecular events involved in the regulation of PGCCs and the generation of their progeny cancer cells, we comparatively analyzed the proteomic profiles of PGCCs, PGCCs with budding daughter cells, and regular control cancer cells from the HEY and SKOv3 human ovarian cancer cell lines with and without CoCl2. We used a high-throughput iTRAQ-based proteomic methodology coupled with liquid chromatography-electrospray ionization tandem mass spectroscopy to determine the differentiated regulated proteins. We performed Western blotting and immunohistochemical analyses to validate the differences in the expression patterns of a variety of proteins between PGCCs or budding PGCCs and regular cancer cells identified by iTRAQ approach and also a selected group of proteins from the literature. The differentially regulated proteins included proteins involved in response to hypoxia, stem cell generation, chromatin remodeling, cell-cycle regulation, and invasion and metastasis. In particular, we found that HIF-1alpha and its known target STC1 are upregulated in PGCCs. In addition, we found that a panel of stem cell-regulating factors and epithelial-to-mesenchymal transition regulatory transcription factors were upregulated in budding PGCCs, whereas expression of the histone 1 family of nucleosomal linker proteins was consistently lower in PGCCs than in control cells. Thus, proteomic expression patterns provide valuable insight into the underlying mechanisms of PGCC formation and the relationship between PGCCs and cancer stem cells in patients with ovarian cancers.
Ect2, a Rho guanine nucleotide exchange factor (RhoGEF), is atypical among RhoGEFs in its predominantly nuclear localization in interphase cells. One current model suggests that Ect2 mislocalization drives cellular transformation by promoting aberrant activation of cytoplasmic Rho family GTPase substrates. However, in ovarian cancers, where Ect2 is both amplified and overexpressed at the mRNA level, we observed that the protein is highly expressed and predominantly nuclear and that nuclear but not cytoplasmic Ect2 increases with advanced disease. Knockdown of Ect2 in ovarian cancer cell lines impaired their anchorage-independent growth without affecting their growth on plastic. Restoration of Ect2 expression rescued the anchorage-independent growth defect, but not if either the DH catalytic domain or the nuclear localization sequences of Ect2 were mutated. These results suggested a novel mechanism whereby Ect2 could drive transformation in ovarian cancer cells by acting as a RhoGEF specifically within the nucleus. Interestingly, Ect2 had an intrinsically distinct GTPase specificity profile in the nucleus versus the cytoplasm. Nuclear Ect2 bound preferentially to Rac1, while cytoplasmic Ect2 bound to RhoA but not Rac. Consistent with nuclear activation of endogenous Rac, Ect2 overexpression was sufficient to recruit Rac effectors to the nucleus, a process that required a functional Ect2 catalytic domain. Furthermore, expression of active nuclearly targeted Rac1 rescued the defect in transformed growth caused by Ect2 knockdown. Our work suggests a novel mechanism of Ect2-driven transformation, identifies subcellular localization as a regulator of GEF specificity, and implicates activation of nuclear Rac1 in cellular transformation.
Ect2; RhoGEF; Rac; ovarian cancer
Elevated Aurora kinase-A expression is correlated with abrogation of DNA damage induced apoptotic response and mitotic spindle assembly checkpoint (SAC) override in human tumor cells. We report that Aurora-A phosphorylation of p73 at serine235 abrogates its transactivation function and causes cytoplasmic sequestration in a complex with the chaperon protein mortalin. Aurora-A phosphorylated p73 also facilitates inactivation of SAC through dissociation of the MAD2-CDC20 complex in cells undergoing mitosis. Cells expressing phosphor-mimetic mutant (S235D) of p73 manifest altered growth properties, resistance to cisplatin induced apoptosis, as well as premature dissociation of the MAD2-CDC20 complex, and accelerated mitotic exit with SAC override in the presence of spindle damage. Elevated cytoplasmic p73 in Aurora-A overexpressing primary human tumors corroborates the experimental findings.
Sex-determining region Y-box 2 (SOX2) is proposed to be a key transcription factor in embryonic stem cells. The known roles of SOX2 in development and cell differentiation suggest that it is relevant to the aberrant growth of tumor cells. Thus, SOX2 may play an important role in tumor progression. However, its clinical significance in human ovarian carcinoma has been uncertain until recently. The aim of the present study was to clarify the clinical role of SOX2 expression in ovarian carcinoma. Immunohistochemical staining of 540 human ovarian carcinoma samples for SOX2 was performed using tissue microarray. The associations among SOX2 expression and clinical factors (diagnosis, tumor grade, International Federation of Gynecology and Obstetrics stage, and response to chemotherapy), overall survival, and disease-free survival were analyzed. We observed SOX2 expression in 15% of the ovarian carcinoma samples. Use of the Fisher exact test suggested that SOX2 expression was associated with high-grade carcinoma (P = .009), especially high-grade serous carcinoma (P = .048); International Federation of Gynecology and Obstetrics stage (II-IV, P = .005); and malignant mixed müllerian tumors (P = .048). SOX2 expression was also associated with decreased disease-free survival durations (P = .035; log-rank test). Our results showed that SOX2 expression may be a potential marker of related to tumor recurrence, as implicated to its role in cancer stem cells.
Sex-determining region Y-box 2 (SOX2); Immunohistochemistry; Ovarian carcinoma; Prognosis
Objective: A prospective, observational study was undertaken to investigate the epidemiology of oral infection among the patients with advanced malignancies, and to investigate the effects of therapy strategies and risk factors on the incidence of oral infection.
Methods: The patients with advanced malignancies were enrolled into the study. The incidence of oral infection with different malignant tumor groups or different treatment methods and the diagnoses of oral infection were confirmed. Demographic data on age, gender, bed rest time, nutritional status, smoking habit and the presence of oral prosthesis were also recorded.
Results: Oral infection was prevalent in 46% (391/850) of all cancer patients, with the highest rate in oral and maxillofacial cancer group (67%), followed by Hematological malignancy group (58.6%) and other groups (ranging from 43.3% to 35.3%). Oral candidiasis, oral herpes simplex, and oral mucositis were the popular infectious diseases in the patients. Chemotherapy and radiotherapy, especially combined radio- and chemotherapy, resulted in more oral infections compared with palliative care and surgery. Poor nutritional status and oral prosthesis were identified as independent risk factors associated with oral infection.
Conclusion: Oral infection is prevalent among advanced cancer patients and associated with therapy methods and risk factors. More oral health care should be carried out for the patients with advanced malignant tumor.
Oral infection; Advanced cancer; Treatment strategy; Oral health
Mixed lineage kinase 3 (MLK3) is a mitogen-activated protein kinase kinase kinase (MAP3K) that activates MAPK signaling pathways and regulates cellular responses such as proliferation, migration and apoptosis. Here we report high levels of total and phospho-MLK3 in ovarian cancer cell lines in comparison to immortalized nontumorigenic ovarian epithelial cell lines. Using small interfering RNA (siRNA)-mediated gene silencing, we determined that MLK3 is required for the invasion of SKOV3 and HEY1B ovarian cancer cells. Furthermore, mlk3 silencing substantially reduced matrix metalloproteinase (MMP) -1, -2, -9 and -12 gene expression and MMP-2 and -9 activities in SKOV3 and HEY1B ovarian cancer cells. MMP-1, -2, -9 and-12 expression, and MLK3-induced activation of MMP-2 and MMP-9 requires both extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase activities. In addition, inhibition of activator protein-1 (AP-1) reduced MMP-1, MMP-9 and MMP-12 gene expression. Collectively, these findings establish MLK3 as an important regulator of MMP expression and invasion in ovarian cancer cells.
MLK3; MMP; invasion; ovarian cancer; MAPK; AP-1
The transition from the closed to open state greatly alters the intra- and inter-subunit interactions of the P2X receptor (P2XR). The interactions that occur in the transmembrane domain of the P2X2R remain unclear. We used substituted cysteine mutagenesis disulfide mapping to identify pairs of residues that are in close proximity within the transmembrane domain of rP2X2R and compared our results to the predicted positions of these amino acids obtained from a rat P2X2R homology model of the available open and closed zebrafish P2X4R structures. Alternations in channel function were measured as a change in the ATP-gated current before and after exposure to dithiothreitol. Thirty-six pairs of double mutants of rP2X2R expressed in HEK293 cells produced normal functioning channels. Thirty-five pairs of these mutants did not exhibit a functionally detectable disulfide bond. The double mutant H33C/S345C formed redox-dependent cross-links in the absence of ATP. Dithiothreitol ruptured the disulfide bond of H33C/S345C and induced a 2 to 3-fold increase in current. The EC50 for H33C/S345C before dithiothreitol treatment was ∼2-fold higher than that after dithiothreitol treatment. Dithiothreitol reduced the EC50 to wild-type levels. Furthermore, expression of trimeric concatamer receptors with Cys mutations at some but not all six positions showed that the more disulfide bond formation sites within the concatamer, the greater current potentiation after dithiothreitol incubation. Immunoblot analysis of H33C/S345C revealed one monomer band under nonreducing conditions strongly suggesting that disulfide bonds are formed within single subunits (intra-subunit) and not between two subunits (inter-subunit). Taken together, these data indicate that His33 and Ser345 are proximal to each other across an intra-subunit interface. The relative movement between the first transmembrane and the second transmembrane in the intra-subunit is likely important for transmitting the action of ATP binding to the opening of the channel.
Recent studies have suggested that some ovarian and pelvic serous carcinomas could originate from the fimbriated end of the distal fallopian tube. To test this hypothesis, we immortalized a normal human fallopian tube epithelial (FTE) cell line by using retrovirus-mediated overexpression of the early region of the SV40 T/t antigens and the human telomerase reverse transcriptase subunit (hTERT). These immortalized FTEs were then transformed by ectopic expression of oncogenic human HRASV12. Tumorigenicity of the immortalized and/or transformed cells was subsequently tested by anchorage-independence growth assay and inoculation into nude mice via subcutaneous and intraperitoneal injection. As expected, the HRASV12-transformed FTEs produced tumors through both subcutaneous and intraperitoneal injections, whereas no tumor growth was observed in immortalized FTEs. Unexpectedly, histopathological examination of tumors resulting from subcutaneous as well as intraperitoneal injections revealed largely poorly differentiated mucinous adenocarcinoma mixed with undifferentiated carcinoma. The tumor implants invaded extensively to the liver, colon, spleen, omentum, adrenal gland and renal capsule. Immunohistochemical staining of tumor cells showed positive staining for the epithelial cell markers cytokeratin AE1/AE3 and Müllerian lineage marker PAX8. Our study demonstrates that FTEs can generate poorly differentiated mucinous adenocarcinoma mixed with undifferentiated carcinoma through genetic modifications. Thus, we provide the first experimental evidence that fimbrial epithelial cells of the fallopian tube could be a potential source of ovarian mucinous adenocarcinoma.
fallopian tube epithelial cells; mucinous adenocarcinoma; oncogene; retrovirus; transformation
High expression of vascular cell adhesion molecule 1 (VCAM1) has been shown to be associated with several cancers although its role in ovarian cancer development is largely undefined. The purpose of this study is to investigate its role in ovarian cancer using the epithelial cells and ovarian cancer cell lines and correlate its expression with clinicopathologic parameters in ovarian cancer patients. VCAM1 expression was examined via immunohistochemical staining of 251 high grade serous carcinoma samples using tissue microarray. The expression of VCAM1 was silenced in RAS-transformed ovarian epithelial cell lines and two high grade ovarian cancer cell lines. Cell migration was analyzed in vitro and effect on tumor growth was analyzed in nude mice. High VCAM1 expression was found to be was related with response to surgery and chemotherapy drugs (P = 0.025) and elder age at diagnosis (P = 0.008). Cox regression multivariable analysis showed that VCAM1 expression in tumor cells was an independent prognostic factor. Ovarian cancer cells with VCAM1 overexpression, compared with corresponding control cells, had increased cell migration and enhanced growth of xenograft tumors in mice. Our data provide strong evidence that VCAM1 plays an important role in ovarian tumor growth, and it may be used as a prognostic factor and novel therapeutic target for ovarian cancer.
Ovarian cancer; VCAM1; overall survival; tumor growth
Cancer has long been considered a disease that mimics an “unhealed wound,” with oncogene-induced secretory activation signals from epithelial cancer cells facilitating stromal fibroblast, endothelial, and inflammatory cell participation in tumor progression. However, the underlying mechanisms that orchestrate cooperative interaction between malignant epithelium and the stroma remain largely unknown. Here, we identified interleukin-1β (IL-1β) as a stromal-acting chemokine secreted by ovarian cancer cells, which suppresses p53 protein expression in cancer-associated fibroblasts (CAFs). Elevated expression of IL-1β and cognate receptor IL-1R1 in ovarian cancer epithelial cells and CAFs independently predicted reduced overall patient survival, as did repressed nuclear p53 in ovarian CAFs. Knockdown of p53 expression in ovarian fibroblasts significantly enhanced the expression and secretion of chemokines IL-8, growth regulated oncogene-alpha (GRO-α), IL-6, IL-1β, and vascular endothelial growth factor (VEGF), significantly increased in vivo mouse xenograft ovarian cancer tumor growth, and was entirely dependent on interaction with, and transcriptional up-regulation of, nuclear factor-kappaB (NF-κB) p65. Our results have uncovered a previously unrecognized circuit whereby epithelial cancer cells use IL-1β as a communication factor instructing stromal fibroblasts through p53 to generate a protumorigenic inflammatory microenvironment. Attenuation of p53 protein expression in stromal fibroblasts generates critical protumorigenic functionality, reminiscent of the role that oncogenic p53 mutations play in cancer cells. These findings implicate CAFs as an important target for blocking inflammation in the tumor microenvironment and reducing tumor growth.
Although the potent anti-tumor activity of nitric oxide (NO) supports its promise as an anti-neoplastic agent, effective and selective delivery and action on tumor and not normal cells remains a limiting factor. Nanoparticle-based delivery of NO has been considered as one approach to overcome these limitations. Therefore, we determined the utility of NO delivery using silica nanoparticles and evaluated their anti-tumor efficacy against human ovarian tumor and nontumor cells. The NO-releasing nanoparticles exhibited enhanced growth inhibition of ovarian tumor cells when compared to both control nanoparticles and a previously reported small molecule NO donor, PYRRO/NO. In addition, the NO-releasing nanoparticles showed greater inhibition of the anchorage-independent growth of tumor-derived and Ras-transformed ovarian cells. Confocal microscopy analysis revealed that fluorescently-labeled NO-releasing nanoparticles entered the cytosol of the cell and localized to late endosomes and lysosomes. Furthermore, we observed a nanoparticle size dependency on efficacy against normal versus transformed ovarian cells. Our study provides the first application of nanoparticle-derived NO as an antitumor therapy and supports the merit for future studies examining nanoparticle formulation for in vivo applications.
Nanoparticle; silica; nitric oxide; ovarian cancer; Ras
A recombinant cysteine protease inhibitor from the human nematode parasite A. lumbricoides has been overexpressed in E. coli, purified and crystallized. Diffraction data were collected to 2.1 Å resolution.
The cysteine protease inhibitor from Ascaris lumbricoides, a roundworm that lives in the human intestine, may be involved in the suppression of human immune responses. Here, the molecular cloning, protein expression and purification, preliminary crystallization and crystallographic characterization of the cysteine protease inhibitor from A. lumbricoides are reported. The rod-shaped crystal belonged to space group C2, with unit-cell parameters a = 99.40, b = 37.52, c = 62.92 Å, β = 118.26°. The crystal diffracted to 2.1 Å resolution and contained two molecules in the asymmetric unit.
cysteine protease inhibitors; nematode parasites; Ascaris lumbricoides