Ruitao Zhang

Effects of metastasis-associated in colon cancer 1 inhibition by small hairpin RNA on ovarian carcinoma OVCAR-3 cells

BackgroundMetastasis-associated in colon cancer 1 (MACC1) is demonstrated to be up-regulated in several types of cancer, and can serve as biomarker for cancer invasion and metastasis. To investigate the relations between MACC1 and biological processes of ovarian cancer, MACC1 specific small hairpin RNA (shRNA) expression plasmids were used to investigate the effects of MACC1 inhibition on ovarian carcinoma OVCAR-3 cells.MethodsExpressions of MACC1 were detected in different ovarian tissues by immunohistochemistry. MACC1 specific shRNA expression plasmids were constructed and transfected into OVCAR-3 cells. Then, expressions of MACC1 were examined by reverse transcription polymerase chain reaction (RT-PCR) and Western blot. Cell proliferation was observed by MTT and monoplast colony formation assay. Flow cytometry and TUNEL assay were used to measure cell apoptosis. Cell migration was assessed by wound healing and transwell migration assay. Matrigel invasion and xenograft model assay were performed to analyze the potential of cell invasion. Activities of Met, MEK1/2, ERK1/2, Akt, cyclinD1, caspase3 and MMP2 protein were measured by Western blot.ResultsOverexpressions of MACC1 were detected in ovarian cancer tissues. Expression of MACC1 in OVCAR-3 cells was significantly down-regulated by MACC1 specific small hairpin RNA. In OVCAR-3 cells, down-regulation of MACC1 resulted in significant inhibition of cell proliferation, migration and invasion, meanwhile obvious enhancement of apoptosis. As a consequence of MACC1 knockdown, expressions of Met, p-MEK1/2, p-ERK1/2, cyclinD1 and MMP2 protein decreased, level of cleaved capase3 was increased.ConclusionsRNA interference (RNAi) against MACC1 could serve as a promising intervention strategy for gene therapy of ovarian carcinoma, and the antitumor effects of MACC1 knockdown might involve in the inhibition of HGF/Met and MEK/ERK pathways.

Misregulation of polo-like protein kinase 1, P53 and P21WAF1 in epithelial ovarian cancer suggests poor prognosis.

Polo-like protein kinase 1 (PLK1), P53 and P21WAF1 are relevant to cell cycle checkpoints and cancer biology. Misregulation of PLK1, P53 and P21WAF1 has been detected in several types of malignant tumors. The present study aimed to clarify the role of PLK1, P53 and P21WAF1 in the prognosis of ovarian cancer. PLK1 and P53 shRNA lentiviral plasmids were transfected into SK-OV-3 cells, respectively. Cell proliferation, apoptosis and invasion were examined by MTT assay, flow cytometry and Matrigel assay, respectively. Survival time of the animals was observed in a xenograft model. Expression levels of PLK1, P53 and P21WAF1 were detected in different ovarian tissues by immunohistochemistry and western blot analysis. Their correlations to the clinicopathologic characteristics of the epithelial ovarian cancer (EOC) cases and their interrelationships were analyzed. Risk factors of prognosis for EOC were determined by logistic regression analysis. The survival time of EOC patients was measured by Kaplan-Meier analysis. After PLK1 or P53 knockdown, proliferation of the SK-OV-3 cells was inhibited, the apoptosis rate was increased, and cell invasion was suppressed in vitro, and the survival time was prolonged in the animals. Expression levels of P53, p-P53 (Ser15), P21WAF1, growth arrest and DNA damage‑inducible gene 45 (GADD45) and 14-3-3σ were upregulated in the SK-OV-3 cells after PLK1 knockdown, but downregulated after P53 knockdown. Higher expression levels of PLK1 and P53 were observed in patients with a higher FIGO stage and worse histological differentiation, but lower P21WAF1 was noted at a higher FIGO stage. Negative correlations were observed between expression of PLK1 and P53 and P53 and P21WAF1 in the EOC cases. PLK1, P53 and P21WAF1 could be used to assess the prognosis of EOC, respectively, but only PLK1 was found to be an independent prognostic factor. The overall survival time of subjects exhibiting PLK1-positive/P53-positive expression and PLK1-positive/P21WAF1-negative expression was obviously shorter than the other patient groups at the end of the follow-up. These results indicate that PLK1 is implicated in ovarian carcinogenesis and may owe its ability to inhibition of the activity of P53. In addition, misregulation of PLK1 coincident with P53 and P21WAF1 in EOC suggests poor prognosis.

Long non-coding RNA CCAT1 promotes metastasis and poor prognosis in epithelial ovarian cancer

&NA; In this study, we reported that long non‐coding RNA (lncRNA) CCAT1 was upregulated in epithelial ovarian cancer (EOC) tissues, and was associated with FIGO stage, histological grade, lymph node metastasis and poor survival of EOC patients. Multivariate Cox regression analysis showed that CCAT1 was an independent prognostic indicator. While CCAT1 downregulation inhibited EOC cell epithelial‐mesenchymal transition (EMT), migration and invasion, CCAT1 upregulation promoted EOC cell EMT, migration and invasion. We further identified and confirmed that miR‐152 and miR‐130b were the targets of CCAT1, and CCAT1 functioned by targeting miR‐152 and miR‐130b. Subsequently, ADAM17 and WNT1, and STAT3 and ZEB1 were confirmed to be the targets of miR‐152 and miR‐130b, respectively, and could be regulated by CCAT1 in EOC cells. Knockdown of anyone of these four proteins inhibited EOC cell EMT, migration and invasion. Taken together, our study first revealed a critical role of CCAT1‐miR‐152/miR‐130b‐ADAM17/WNT1/STAT3/ZEB1 regulatory network in EOC cell metastasis. These findings provide great insights into EOC initiation and progression, and novel potential therapeutic targets and biomarkers for diagnosis and prognosis for EOC. HighlightsCCAT1 is upregulated in EOC and associated with the prognosis of EOC patients.CCAT1 promotes EOC cell EMT, migration and invasion.miR‐152 and miR‐130b are the targets of CCAT1.ADAM17 and WNT1, and STAT3 and ZEB1 are separately targets of miR‐152 and miR‐130.CCAT1 functions via regulation of ADAM17, WNT1, STAT3 and ZEB1 expression.

Knockdown of MACC1 expression increases cisplatin sensitivity in cisplatin-resistant epithelial ovarian cancer cells

Abnormal expression of metastasis-associated in colon cancer 1 (MACC1) was found to be closely associated with several types of malignant tumors. The present study aimed to verify the relationship between MACC1 and cisplatin resistance in ovarian cancer cells and the possible mechanisms, which was implemented by inhibition of the expression of MACC1 in cisplatin-resistant human ovarian cancer cell lines A2780/DDP and COC1/DDP. MACC1 shRNA eukaryotic plasmids and negative control plasmids were transfected into A2780/DDP and COC1/DDP cells, respectively, while A2780/DDP and COC1/DDP cells were used as blank controls. Western blotting and sqRT-PCR were used to detect the expression of MACC1 in the different cell groups. Different concentrations of cispaltin (0, 10, 20, 30, 40, 50 and 60 µmol/l) were used to treat the cell groups, respectively, and then the chemosensitivity of cisplatin and cell apoptosis were examined by MTT and flow cytometry, respectively. The activity of caspase-3 was determined by spectrophotometry. Expression levels of p-ERK1/2, permeability glycoprotein (P-gp), B-cell lymphoma 2 (Bcl-2), Bcl-XL, Bax and Bad protein were detected in the different ovarian cancer cells by western blotting. After MACC1 knockdown, the chemosensitivity of cisplatin in the ovarian cancer cells was enhanced, and the cell growth inhibition and apoptosis rates were increased. The expression levels of Bax and Bad were upregulated, the activity of caspase-3 was increased, while the expression levels of p-ERK1/2, P-gp, Bcl-2 and Bcl-XL were downregulated as a result of MACC1 inhibition. These results indicate that inhibition of MACC1 improves the chemosensitivity of cisplatin in epithelial ovarian cancer cells, through the regulation of the ERK1/2 signaling pathway on P-gp and its downstream apoptosis proteins.

Expression of deleted in liver cancer 1 and plasminogen activator inhibitor 1 protein in ovarian carcinoma and their clinical significance

BackgroundThe deleted in liver cancer 1 (DLC1) and plasminogen activator inhibitor 1 (PAI-1) are known to be closely associated with tumor growth and metastasis in several kinds of human tumors. The aim of this study was to investigate the expression of DLC1 and PAI-1 in ovarian carcinoma, and evaluate their relations with the prognosis of ovarian carcinoma.MethodsImmunohistochemical staining and Western blot were used to examine the expressions of DLC1 and PAI-1 protein in 25 specimens normal ovarian tissues, 52 specimens of serous cystadenocarcinoma tissues and 23 specimens of mucinous cystadenocarcinoma tissues. Chi-square test, Logistic regression and Partial Correlate analysis were performed to evaluate the association between DLC1 and PAI-1 with clinicopathological characteristics. Overall survival was estimated by Kaplan-Meier curves and multivariate Cox analysis. The relationships between DLC1 and PAI-1 protein expression were analyzed by Pearson’s correlation coefficient.ResultsThe expression of DLC1 protein in ovarian carcinoma tissues was significantly lower than that in normal ovarian tissues, but it was converse for PAI-1. In ovarian carcinoma, the expression of DLC1 was significantly associated with advanced FIGO stage, ascites and positive lymph node metastasis, whereas PAI-1 protein was closely related with advanced FIGO stage, poor histological differentiation and lymph node metastasis. The expression of DLC1 was negatively correlated with PAI-1 in ovarian carcinoma. Ovarian cancer patients with negative expression of DLC1 and positive expression of PAI-1 had the worst overall survival time compared to other patients.ConclusionsThe expression of DLC1 and PAI-1 were closely related with the metastasis and invasion of ovarian carcinoma, only the combination of DLC1 and PAI-1 could serve as an independent prognostic factor of ovarian carcinoma.

Effects of kallikrein-related peptidase 14 gene inhibition by small interfering RNA in ovarian carcinoma cells

Kallikrein-related peptidase 14 (KLK14) is a member of the tissue kallikrein family of proteases, which are associated with the pathogenesis of malignant tumors and are over-expressed in ovarian carcinoma. However, the mechanism through which KLK14 is implicated in ovarian cancer remains unclear. The aim of the present study was to investigate the effects of KLK14 gene inhibition by small interfering RNA (siRNA) on the growth, apoptosis and invasion of ovarian carcinoma cells in vitro. KLK14 siRNA was transiently transfected into SK-OV-3 and OVCAR-3 ovarian carcinoma cells for 48 h. The expression of KLK14 was determined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. Cell proliferation, apoptosis and invasion were examined by MTT, flow cytometry and Matrigel assay, respectively. The expression of survivin, caspase 9, cleaved caspase 3 and MMP2 protein was measured by Western blot analysis. The expression of KLK14 was significantly downregulated by siRNA in SK-OV-3 and OVCAR-3 cells at both the mRNA and protein levels. Following transfection with KLK14 siRNA, cell growth and invasion were significantly suppressed, and cell apoptosis was markedly induced. The expression of survivin and MMP2 was decreased, while the espression of caspase 9 and cleaved caspase 3 was increased. These results indicate that KLK14 is implicated in the malignant behavior of ovarian carcinoma cells in vitro, and that KLK14 may serve as a target for therapy of ovarian carcinoma.

The aberrant upstream pathway regulations of CDK1 protein were implicated in the proliferation and apoptosis of ovarian cancer cells

BackgroundUpregulation of Cyclin dependent kinase 1 (CDK1) protein is closely related with the prognosis of several malignant tumors. Chk1-CDC25C-CDK1 signaling and P53-P21WAF1-CDK1 signaling pathways are closely related with the cell cycle G2/M phase regulation. The present study aimed to analyze the relationship between CDK1 and the proliferation and apoptosis of ovarian cancer cells, investigate its molecular mechanism preliminarily.MethodsThe specific short-hair RNA (shRNA) plasmids and negative control plasmid of CDK1, checkpoint kinase 1 (CHK1) and p53 genes were transfected into ovarian cancer SK-OV-3 and OVCAR-3 cells respectively. The expressions of CDK1, CHK1 and p53 mRNA and CDK1, Chk1 and P53 protein were detected by sqRT-PCR and Western blot, levels of phospho-CDK1(Thr14/Tyr15), CyclinB1, phospho-Chk1(ser345), cell division cycle 25C (CDC25C), phospho-CDC25C(ser216), P21WAF1, phospho-P53(ser15), proliferating cell nuclear antigen (PCNA), Ki-67, Bcl-2, Bax, Caspase8, Cleaved-caspase3 and Cytochrome C were examined by Western blot. The cell proliferation was measured by MTT and Trypan blue exclusion assay respectively, the cell cycle phase distribution and cell apoptosis rate were detected by flow cytometry (FCM) assay.ResultsAs results of CDK1 inhibition by shRNA, the cell proliferation was repressed, the cell numbers of G2/M phase and cell apoptosis rate were increased in both SK-OV-3 and OVCAR-3 cells. After knockdown of CDK1, expressions of PCNA, Ki-67 and Bcl-2 protein were downregulated, expressions of Bax, Caspase8, Cleaved-caspase3 and Cytochrome C were upregulated. While knockdown the CHK1 and p53 by shRNA respectively, the similar effects were observed on the cell proliferation, cell cycle phase distribution and apoptosis in both SK-OV-3 and OVCAR-3 cells, as well as the expressions of the proliferation and apoptosis related proteins mentioned above. Moreover, the levels of p-CDK1(Thr14/Tyr15) were increased after either CHK1 inhibition or p53 inhibition.ConclusionsAbnormal activation of CDK1 was implicated in the proliferation and apoptosis regulation of ovarian cancer cells, which might be due to the aberrant regulations of the upstream Chk1-CDC25C and P53-P21WAF1 signaling pathway.