[Show abstract][Hide abstract] ABSTRACT: This study was designed to investigate whether proton pump inhibitors (PPI, V-ATPase blocker) could increase the effect of cytotoxic agents in chemoresistant epithelial ovarian cancer (EOC). Expression of V-ATPase protein was evaluated in patients with EOC using immunohistochemistry, and patient survival was compared based on expression of V-ATPase mRNA from a TCGA data set. In vitro, EOC cell lines were treated with chemotherapeutic agents with or without V-ATPase siRNA or PPI (omeprazole) pretreatment. Cell survival and apoptosis was assessed using MTT assay and ELISA, respectively. In vivo experiments were performed to confirm the synergistic effect with omeprazole and paclitaxel on tumor growth in orthotopic and patient-derived xenograft (PDX) mouse models. Expression of V-ATPase protein in ovarian cancer tissues was observed in 44 patients (44/59, 74.6%). Higher expression of V-ATPase mRNA was associated with poorer overall survival in TCGA data. Inhibition of V-ATPase by siRNA or omeprazole significantly increased cytotoxicity or apoptosis to paclitaxel in chemoresistant (HeyA8-MDR, SKOV3-TR) and clear cell carcinoma cells (ES-2, RMG-1), but not in chemosensitive cells (HeyA8, SKOV3ip1). Moreover, the combination of omeprazole and paclitaxel significantly decreased the total tumor weight compared with paclitaxel alone in a chemoresistant EOC animal model and a PDX model of clear cell carcinoma. However, this finding was not observed in chemosensitive EOC animal models. These results show that omeprazole pretreatment can increase the effect of chemotherapeutic agents in chemoresistant EOC and clear cell carcinoma via reduction of the acidic tumor microenvironment.
[Show abstract][Hide abstract] ABSTRACT: Bromodomain containing protein 7 (BRD7) which is a subunit of SWI/SNF complex has been recently suggested a novel tumor suppressor in several cancers. In this study, we investigated the tumor suppressive effect of BRD7 in epithelial ovarian cancer.
We analyzed the expression of BRD7 in human ovarian tissues with real-time PCR. To investigate the functional role of BRD7, we transfected ovarian cancer cells (A2780 and SKOV3) with BRD7 plasmid and checked the cell viability, apoptosis and invasion. The activities of BRD7 in the signaling pathways associated with carcinogenesis were also tested. In addition, we used the orthotopic mouse model for ovarian cancer to evaluate tumor growth-inhibiting effect by administration of BRD7 plasmid.
The BRD7 expression was down-regulated in the ovarian cancer tissues compared with normal (P < 0.05), high-grade serous cancer exhibited significantly decreased expression of BRD7 compared with low-grade (P < 0.01). Transfection of BRD7 plasmid to A2780 (p53-wild) or SKOV3 (p53-null) ovarian cancer cells showed the tumor suppressive effects assessed by cell viabilitiy, apoptosis and invasion assay and especially significantly decreased tumor weight in orthotopic mouse model (A2780). Moreover, we found that tumor suppressive effects of BRD7 are independent to the presence of p53 activity in ovarian cancer cells. BRD7 negatively regulated β-catenin pathway resulting in decreased its accumulation in the nucleus.
These results suggested that BRD7 acts as a tumor suppressor in epithelial ovarian cancers independently of p53 activity, via negative regulation of β-catenin pathway.
No preview · Article · Nov 2013 · Clinical Cancer Research
[Show abstract][Hide abstract] ABSTRACT: Galectin-7 (GAL-7) has been highlighted as an important marker in many types of cancers by either inhibiting or promoting tumor growth. In this novel study, we assessed the association of GAL-7 with clinicopathological variables and survival outcomes in epithelial ovarian cancer (EOC) and investigated the role of GAL-7 in proliferation of ovarian cancer cell lines.
The expression of GAL-7 was determined in 63 formalin-fixed, paraffin-embedded EOC tissues using an immunohistochemical method and we compared various associated clinicopathological factors. To evaluate the role of GAL-7 in cell proliferation, we performed proliferation assays with GAL-7 siRNA using ovarian cancer cell lines, including A2780-PAR cells.
Immunohistochemical analysis revealed that GAL-7 expression was primarily detected in nuclei and occasionally in the nucleus and cytoplasm. High GAL-7 expression was associated with greater age (p=0.016), high mortality (p=0.025), and poor overall survival outcome (p=0.029). In addition, the residual tumor volume was larger in the high-expression group compared to the low-expression group, although the difference was not statistically significant (p=0.059). Down-regulation of GAL-7 using siRNA resulted in the inhibition of cell proliferation of A2780-PAR cells.
We observed that high GAL-7 might be associated with poor survival outcome in patients with EOC, and may be functionally involved in cell proliferation.
No preview · Article · Apr 2013 · Anticancer research
[Show abstract][Hide abstract] ABSTRACT: Galectin 1 is a 14-kd laminin-binding lectin involved in important biologic mechanisms of tumors, including neoplastic transformation, cell survival, angiogenesis, cell proliferation, and metastasis. In this study, we investigated the role of galectin 1 in cell survival and metastasis in cervical cancer. The expression of galectin 1 was determined in 73 formalin-fixed, paraffin-embedded cervical cancer tissues using an immunohistochemical method and compared with clinicopathologic risk factors for recurrence after surgery. To evaluate the role of galectin 1 in cell proliferation and invasion, we performed proliferation and invasion assays with galectin 1 small interfering RNA (siRNA) using cervical cancer cell lines, including HeLa and SiHa cells. Immunohistochemical analysis revealed that galectin 1 expression was found in most peritumoral stroma samples (72/73; 98.6%). Galectin 1 expression was significantly correlated with the depth of invasion in the cervix (P=.015) and lymph node metastasis (P=.045) on univariate analysis. When progression-free survival of all of the patients studied was analyzed based upon galectin 1 expression, galectin 1 expression was not correlated with progression-free survival (P=.32). Down-regulation of galectin 1 using small interfering RNA resulted in the inhibition of cell growth and proliferation of HeLa and SiHa cells. Moreover, the ability of cells to invade was significantly reduced by galectin 1 small interfering RNA. Our results revealed that high galectin 1 expression in peritumoral stroma was significantly correlated with depth of invasion in cervical lesions and lymph node metastasis of cervical cancer and that galectin 1 may be functionally involved in cell proliferation and invasion.
[Show abstract][Hide abstract] ABSTRACT: Epidemiological studies suggest that selenium protects against the development of several cancers. Selenium (sodium selenite) has been reported to interfere with cell growth and proliferation, and to induce cell death. In this study, we tested whether selenium could have growth-inhibiting effect in ovarian cancer cells and an orthotopic animal model.
Cell growth in selenium-treated cells was determined in human ovarian cancer cells, A2780, HeyA8, and SKOV3ip1 using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) assay. Animal experiment of selenium with paclitaxel was performed using SKOV3ip1 cells in nude mice to evaluate their inhibiting effect for tumor growth. In addition, another animal experiment of paclitaxel with or without selenium was performed to assess the effect of survival and food intake in mice.
The in vitro growth of selenium-treated cells was significantly decreased dose-dependently in A2780, HeyA8, and SKOV3ip1 cells. Therapy experiment in mice was started 1 week after injection of the SKOV3ip1 cells. Treatment with selenium (1.5 mg/kg, 3 times/week) and paclitaxel injection showed no addictive effect of the inhibition of tumor growth. However, combination of selenium and paclitaxel showed the slightly increased food intake compared with paclitaxel alone.
Although selenium has growth-inhibiting effect in ovarian carcinoma cells in vitro, there is no additive effect on tumor growth in mice treated with combination of paclitaxel and selenium. However, food intake is slightly higher in selenium-treated mice during chemotherapy.
[Show abstract][Hide abstract] ABSTRACT: Chemoresistance is a main cause for the failure of cancer management and intensive investigation is on-going to control chemoresistant (CR) cancers. Although NF-κB has been suggested as one of the potential targets to alleviate chemoresistance of epithelial ovarian cancer (EOC), direct targeting of NF-κB may result in an unexpected effect due to the complex regulatory network via NF-κB. Here we show that AIMP2-DX2, a splicing variant of tumor suppressor AIMP2, can be a therapeutic target to control CR EOC. AIMP2-DX2 was often highly expressed in CR EOC both in vitro and in vivo. AIMP2-DX2 compromised the tumor necrosis factor alpha-dependent pro-apoptotic activity of AIMP2 via the competitive inhibition of AIMP2 binding to TRAF2 that plays a pivotal role in the regulation of NF-κB. The direct delivery of siRNA against AIMP2-DX2 into abdominal metastatic tumors of ovarian cancer using a microneedle converged on microendoscopy significantly suppressed the growth rate of tumors. The treated cancer tissues showed an enhanced apoptosis and the decreased TRAF2 level. Thus, we suggest that the downregulation of AIMP2-DX2 can be a potent adjuvant therapeutic approach for CR EOC that resulted from an aberrant activity of NF-κB.
[Show abstract][Hide abstract] ABSTRACT: Galectin-1 (Gal-1) is a 14-kDa laminin-binding galectin involved in several biological events including regulation of tumour proliferation and metastasis. In this study, we investigated the clinical significance of Gal-1 expression and its functional role in cell proliferation and invasion in epithelial ovarian cancer (EOC).
We evaluated the expression of Gal-1 in 52 serous, 11 endometrioid, and 3 mucinous type EOC tumour samples from 66 patients by immunohistochemistry. In vitro experiments were performed to determine the function of Gal-1 in cell survival, proliferation, and invasion in EOC cells using siRNA and anginex, a Gal-1 inhibitor, as well as recombinant Gal-1 protein.
Patients with strong Gal-1 peritumoural staining had poorer progression-free survival (PFS) than patients with weak peritumoural staining (p=0.03). Inhibition of Gal-1 by siRNA or anginex resulted in the inhibition of cell growth and proliferation of HeyA8 and SKOV3ip1 cells. Moreover, the ability of cells to migrate was significantly reduced by treatment of cells with Gal-1 siRNA but was increased by treatment of cells with recombinant Gal-1. When we evaluated the interaction between fibroblasts (T HESCs) and cancer cells (A2780-CP20), we found that MMP-2 expression in cancer cells was affected by Gal-1 secreted by fibroblast cells, which suggests that Gal-1 in human fibroblasts might affect the invasive abilities of tumour cells.
Our results suggest that Gal-1 expression is a potential prognostic factor for PFS and that Gal-1 could be a novel treatment target in EOC patients.
No preview · Article · Mar 2012 · European journal of cancer (Oxford, England: 1990)
[Show abstract][Hide abstract] ABSTRACT: Increased expression of miR-200c was recently reported in endometrial carcinoma compared with normal tissues. In this study, we evaluated the role of miR-200c in cell growth and drug sensitivity in endometrial carcinoma and investigated the underlying mechanisms.
The expression of miR-200c in human endometrial tissues was detected by quantitative RT-PCR. The transfection with anti-miRNA (anti-miR) or the premature form of miRNA (pre-miR) was performed to regulate the level of expression of miRNA-200c in endometrial carcinoma cells, HEC-1A and Ishikawa. To identify the target genes for miR-200c, we performed mRNA microarray after pre-miR-200c transfection in HEC-1A cells.
We found that miR-200c expression was increased in endometrial carcinoma compared with normal endometrial tissues. Anti-miR or pre-miR-200c could regulate cell survival, proliferation, and apoptosis and affect cytotoxicity in endometrial cancer cells. Through mRNA microarray analysis, we found that miR-200c inhibits the expression of BRD7, which was recently reported as a potential tumor suppressor gene. MiR-200c regulated the translocation of β-catenin from the cytoplasm to the nucleus via inhibition of BRD7, resulting in increased expression of its transcriptional target genes, cyclinD1 and c-myc.
The interaction between miR-200c and BRD7 might have important roles in controlling growth of endometrial of cancer cells and suggest a novel target pathway for treatment of this cancer.
No preview · Article · Jan 2012 · Gynecologic Oncology
[Show abstract][Hide abstract] ABSTRACT: Galectin-3 (Gal-3) is a β-galactoside-binding lectin involved in regulating cell growth, angiogenesis, and tumor progression. We investigated the clinical significance of Gal-3 expression including its possible use as a prognostic marker or therapeutic target in epithelial ovarian carcinoma (EOC).
Gal-3 expression was evaluated by immunohistochemistry in 71 patients with 54 serous, 13 endometrioid, and 4 mucinous ovarian carcinomas. We assessed the correlation of Gal-3 expression with clinical characteristics including histology, optimal debulking, chemosensitivity, and survival. In vitro, Gal-3 was inhibited using siRNA to evaluate its role in cell growth and sensitivity to chemotherapeutic agents in ovarian carcinoma cell lines.
Gal-3 protein, which was mainly cytoplasmic in location, was observed in a majority (63/71, 88.7%) of the EOCs but not in normal ovarian tissues (P < 0.001). High Gal-3 expression in EOCs correlated with shorter progression-free survival (PFS) of patients (P = 0.039; 43.1 and 49.5 months, respectively). Moreover, cotreatment with Gal-3 siRNA and paclitaxel showed an enhanced cytotoxic effect compared with control siRNA in SKOV3 cells.
These findings suggest that Gal-3 expression can be a prognostic factor for PFS and may be involved in regulating the response to paclitaxel-based chemotherapy in the treatment of EOC.
No preview · Article · Feb 2011 · International Journal of Clinical Oncology
[Show abstract][Hide abstract] ABSTRACT: Claudin-7 (CLDN-7) is a tight junction protein that has been shown overexpressed in several human cancers. We investigated prognostic significance of CLDN-7 overexpression in patients with epithelial ovarian carcinoma (EOC) and its functional role on cell proliferation in ovarian carcinoma cell lines.
CLDN-7 expression was evaluated by real-time RT-PCR and immunohistochemical analysis in 71 patients with EOC. We assessed the association of CLDN-7 expressions with prognosis of the patients including sensitivity to platinum-based chemotherapy. In vitro experiment was performed with and without inhibition of CLDN-7 by its siRNA to evaluate the sensitivity of the human ovarian cancer cells to cisplatin chemotherapy.
CLDN-7 transcripts in EOCs were significantly up-regulated compared with normal ovarian tissues (P<0.001). The expression of CLDN-7 protein was observed in majority (69/71, 97.1%) of the EOCs but not in normal ovarian tissues (P<0.001). High CLDN-7 expression in primary tumour correlated with shorter progression-free survival (PFS) of the patients (P=0.005) and poor sensitivity to platinum-based chemotherapy (P=0.024). Moreover, CLDN-7 was highly expressed in 2774 and HeyA8 human ovarian cancer cells and inhibition of CLDN-7 by its siRNA significantly enhanced the sensitivity of 2774 and HeyA8 cells to cisplatin treatment.
These findings suggest CLDN-7 expression is an independent prognostic factor for PFS and it may play a role in regulating response to platinum-based chemotherapy in the treatment of EOC.
No preview · Article · Dec 2010 · European journal of cancer (Oxford, England: 1990)