microRNA 31 functions as an endometrial cancer oncogene by suppressing Hippo tumor suppressor pathway.

BACKGROUND: We aimed to investigate whether MIR31 is an oncogene in human endometrial cancer and identify the target molecules associated with the malignant phenotype. METHODS: We investigated the growth potentials of MIR31-overexpressing HEC-50B cells in vitro and in vivo. In order to identify the target molecule of MIR31, a luciferase reporter assay was performed, and the corresponding downstream signaling pathway was examined using immunohistochemistry of human endometrial cancer tissues. We also investigated the MIR31 expression in 34 patients according to the postoperative risk of recurrence. RESULTS: The overexpression of MIR31 significantly promoted anchorage-independent growth in vitro and significantly increased the tumor forming potential in vivo. MIR31 significantly suppressed the luciferase activity of mRNA combined with the LATS2 3'-UTR and consequently promoted the translocation of YAP1, a key molecule in the Hippo pathway, into the nucleus. Meanwhile, the nuclear localization of YAP1 increased the transcription of CCND1. Furthermore, the expression levels of MIR31 were significantly increased (10.7-fold) in the patients (n = 27) with a high risk of recurrence compared to that observed in the low-risk patients (n = 7), and this higher expression correlated with a poor survival. CONCLUSIONS: MIR31 functions as an oncogene in endometrial cancer by repressing the Hippo pathway. MIR31 is a potential new molecular marker for predicting the risk of recurrence and prognosis of endometrial cancer.

Evaluation of the role of kefir in management of non-alcoholic steatohepatitis rat model via modulation of NASH linked mRNA-miRNA panel.

Non-alcoholic steatohepatitis (NASH) is the clinically aggressive variant of non-alcoholic fatty liver disease. Hippo pathway dysregulation can contribute to NASH development and progression. The use of probiotics is effective in NASH management. Our aim is to investigate the efficacy of kefir Milk in NASH management via modulation of hepatic mRNA-miRNA based panel linked to NAFLD/NASH Hippo signaling and gut microbita regulated genes which was identified using bioinformatics tools. Firstly, we analyzed mRNAs (SOX11, SMAD4 and AMOTL2), and their epigenetic regulator (miR-6807) followed by validation of target effector proteins (TGFB1, IL6 and HepPar1). Molecular, biochemical, and histopathological, analyses were used to evaluate the effects of kefir on high sucrose high fat (HSHF) diet -induced NASH in rats. We found that administration of Kefir proved to prevent steatosis and development of the inflammatory component of NASH. Moreover, Kefir improved liver function and lipid panel. At the molecular level, kefir down-regulated the expression of miR 6807-5p with subsequent increase in the expression of SOX 11, AMOTL2 associated with downregulated SMAD4, resulting in reduction in the expression of the inflammatory and fibrotic markers, IL6 and TGF-ß1 in the treated and prophylactic groups compared to the untreated rats. In conclusion, Kefir suppressed NASH progression and improved both fibrosis and hepatic inflammation. The produced effect was correlated with modulation of SOX11, SMAD4 and AMOTL2 mRNAs) - (miR-6807-5p) - (TGFB, IL6 and, HepPar1) expression.

Intracellular clusterin negatively regulates ovarian chemoresistance: compromised expression sensitizes ovarian cancer cells to paclitaxel.

Understanding the molecular events that lead to paclitaxel (TX) resistance is necessary to identify effective means to prevent chemoresistance. Previously, results from our lab revealed that secretory clusterin (CLU) form positively mediates TX response in ovarian cancer cells. Thus, we had interest to study the role of another non-secreted form (intracellular clusterin (i-CLU)) in chemo-response. Here, we provide evidences that i-CLU form localizes mainly in the nucleus and differentially expressed in the TX-responsive KF cells, versus TX-resistant, KF-TX, ovarian cancer cells and negatively regulate cellular chemo-response. I-CLU was cloned, by deleting the secretion-leading signaling peptide from full-length CLU cDNA, and transiently over-expressed in OVK-18 cells. Forced expression of truncated i-CLU was mainly detectable in the nuclei and significantly reduced cellular growth, accumulating cells in G1 phase which finally died through apoptosis. Importantly, compromised expression of i-CLU under an inducible promoter was tolerated and did not induce apoptosis but sensitized ovarian cancer cells to TX. We then demonstrated that this sensitization mechanism was cell cycle independent and relied on i-CLU/Ku70 binding probably due to controlling the free amount of Ku70 available for DNA repair in the nucleus. Results from CLU immunohistochemistry in ovarian tumor tissues verified the retardation of nuclear CLU staining in the recurrent tumor even though their primary counterparts showed nuclear CLU staining. Thus, the controversial data on CLU function in chemo-response/resistance may be explained by a shift in the pattern of CLU expression and intracellular localization as well when tumor acquires chemoresistance.

Clusterin expression predicts survival of invasive cervical cancer patients treated with radical hysterectomy and systematic lymphadenectomy.

OBJECTIVES: The aim of this study was to evaluate the prognostic significance of clusterin expression in invasive cervical cancer patients treated with radical hysterectomy and systematic lymphadenectomy. METHODS: Invasive cervical cancer specimens were obtained from 52 patients who underwent radical hysterectomy and systematic lymphadenectomy at Hokkaido University Hospital from 1997 to 2004. The expression of clusterin protein was analyzed by immunohistochemical staining. Findings were evaluated in relation to several clinicopathological factors. Survival analyses were performed by the Kaplan-Meier curves and the log-rank test. Independent prognostic factors were determined by multivariate Cox regression analysis. RESULTS: Clusterin protein was present in the cytoplasm of cervical cancer cells. The expression of clusterin protein in invasive cervical cancer tissues was not related to any clinicopathologic factors analyzed. Patients with positive clusterin expression showed significantly worse prognosis than those with negative clusterin expression (p=0.017). Multivariate analysis including clusterin expression revealed that clusterin expression (p=0.006) and the number of positive node groups (p=0.002) were independent prognostic factors for survival. Survival of patients with invasive cervical cancer could be stratified into three groups by combination of clusterin expression and number of positive node groups with an estimated 5-year survival rate of 100.0% for no or one positive node group irrespective of clusterin expression (group A), 78.7% for multiple node groups with negative clusterin expression (group B), and 14.3% for multiple node groups with positive clusterin expression (group C) (p=0.03 for group A vs. group B, p=0.004 for group B vs. group C, and p<0.0001 for group A vs. group C). CONCLUSIONS: Clusterin expression and the number of positive node groups were independent prognostic factors for invasive cervical cancer patients treated with radical hysterectomy and systematic lymphadenectomy. Clusterin might be a new molecular marker to predict the survival of cervical cancer patients with multiple positive node groups.

miR-363 confers taxane resistance in ovarian cancer by targeting the Hippo pathway member, LATS2.

Ovarian cancer is the most aggressive female reproductive tract tumours. Taxane (paclitaxel; TX) is widely used for ovarian cancer treatment. However, ovarian cancers often acquire chemoresistance. MicroRNAs (miR) have been reported to mediate many tumours'chemoresistance. We investigated the role of miR-363 in the chemoresistance of the ovarian cancer cell line, KF, and its TX-resistant derivative (KF-TX) cells. QRT-PCR indicated that miR-363 was upregulated in KF-TX cells, and introduction of miR-363 into sensitive ovarian cancer cells confers TX-resistance and significantly inhibited the expression of the Hippo member, LATS2, as indicated by viability, clonogenic assay and expression analysis. Furthermore, we validated the role of LATS2 in TX-response by sh-based silencing, which also confers TX-resistance to the ovarian cancer cells. On the other hand, specific inhibitor against miR-363 restored the response to TX in the resistant cells. In addition, miR-363 was found to bind to the 3'-UTR of LATS2 mRNA, confirming that miR-363 directly targets LATS2 as indicated by dual luciferase assay. RT-PCR-based evaluation of miR-363 in a panel of human ovarian tumours revealed its upregulation in most of the tumour tissues identified as resistant while it was downregulated in most of the tissues identified as sensitive ones. Moreover, higher levels of miR-363 in human ovarian cancer specimens were significantly correlated with TX chemoresistance. Taken together, our study reveals the involvement of miR-363 in chemoresistance by targeting LATS2 in ovarian cancers, raising the possibility that combination therapy with a miR-363 inhibitor and TX may increase TX efficacy and reduce the chance of TX-resistance.

Canagliflozin prevents scopolamine-induced memory impairment in rats: Comparison with galantamine hydrobromide action.

Canagliflozin (CAN) is a sodium-glucose co-transporter 2 (SGLT2) inhibitor indicated to improve glycemic control in adults with type 2 diabetes mellitus. There is a little information about its effect on the cholinergic system that proposed mechanism for memory improvement occurring by SGLT2 drugs. This study aimed to estimate the effect of CAN as compared to galantamine (GAL) treatments for two weeks on scopolamine hydrobromide (SCO)-induced memory dysfunction in experimental rats. Animals divided into six groups; control (CON), CAN, GAL, SCO, SCO + CAN and SCO + GAL. Results indicated significant decrease in body weights of the CAN groups as compared to control values. Moreover, in the SCO + CAN and SCO + GAL the number of arm entry and number of correct alternation in Y maze task increased and showed improvement in the water maze task, acetylcholinesterase (AChE) activities decreased significantly, while monoamines levels significantly increased compared with the SCO group values. Results also recorded acetylcholine M1 receptor (M1 mAChR) in SCO + CAN or SCO + GAL groups in comparison with the SCO group. The study suggested that canagliflozin might improve memory dysfunction induced by scopolamine hydrobromide via cholinergic and monoamines system.

P18/Stathmin1 is regulated by miR-31 in ovarian cancer in response to taxane.

MicroRNAs (miRNAs) have been reported to regulate the development of chemoresistance in many tumors. Stathmin 1 (STMN1) is a microtubule-depolymerizing molecule, involved in chemo-response; however, the mechanism of its regulation is unknown. Herein, the immunohistochemical study indicated significant upregulation of the STMN1 in the ovarian cancer tissues defined as resistant tumors compared with those defined as responsive tumors. STMN1 level elevated in the chemoresistant ovarian cancer cells, KF-TX, compared with the parental, KF, ones. Targeting STMN1 by siRNA restored taxane-sensitivity of KF-TX cells. Screening miRNA profiles from KF/KF-TX cellular set followed by bioinformatics-based prediction, revealed that miR-31 could be a possible regulator of STMN1. Down-modulation of miR-31 was verified by quantitative RT-PCR in the cellular set used. Overexpression of miR-31 in KF-TX cells (KF-TX-miR-31) significantly restored chemo-response and reduced STMN1 expression as well. STMN1 reduction-associated cellular characteristics such as enhanced microtubule polymerization and stability, as indicated by acetylated tubulin quantification, confocal visualization, and G2 phase delay, were observed in KF-TX-miR-31 cells, indicating the functional reduction of STMN1. miR-31 suppressed the luciferase activity in reporter construct containing the STMN1 3'-untranslated region (3'-UTR), confirming that miR-31 directly targets STMN1. miR-31 has therapeutic potency when introduced into ovarian cancer, in combination with taxane.

Clusterin expression inversely correlates with chemosensitivity and predicts poor survival in patients with locally advanced cervical cancer treated with cisplatin-based neoadjuvant chemotherapy and radical hysterectomy.

Overexpression of clusterin, an antiapoptotic molecule, has been reported to induce resistance to chemotherapy in a variety of cancer cell types. The aim of this study was to evaluate the significance of clusterin expression to predict response to platinum-based neoadjuvant chemotherapy and survival of patients with invasive cervical cancer who subsequently underwent radical hysterectomy. Biopsy specimens of invasive cervical cancer before neoadjuvant chemotherapy were obtained from 46 patients who subsequently underwent radical hysterectomy at Hokkaido University Hospital and Gunma University Hospital from 1994 to 2007. The expression of clusterin protein was analyzed by immunohistochemistry. Findings were evaluated in relation to several clinicopathological factors. Survival analyses were performed by the Kaplan-Meier curves and the log-rank test. Independent prognostic factors were determined by multivariate Cox regression analysis. Clusterin protein was mainly present in the cytoplasm of cervical cancer cells. The expression of clusterin protein in cervical cancer tissues before neoadjuvant chemotherapy was significantly related to poor response to chemotherapy among factors analyzed. Univariate analysis on prognostic factors showed that response to chemotherapy (p = 0.01), lymph node metastasis (p = 0.02), and clusterin expression (p = 0.02) were related to survival. Multivariate analysis revealed that lymph node metastasis (p = 0.03), and clusterin expression (p = 0.03) were independent prognostic factors for survival of cervical cancer patients. We conclude that clusterin expression could be a new molecular marker to predict response to platinum-based chemotherapy and survival of patients with cervical cancer treated with neoadjuvant chemotherapy and radical hysterectomy.