Resveratrol is a naturally occurring trihydroxyl-diphenylethylene compound that has been shown experimentally to have beneficial effects in the treatment of cancer and cardiovascular disease. Resveratrol induces programmed cell death (apoptosis) in these cells and activates important signal transducing proteins including extracellular signal-regulated kinases (ERKs) 1 and 2 in cancer cells. Resveratrol also causes nuclear accumulation of the enzyme cyclooxygenase (COX)-2 and of the oncogene suppressor protein, p53. We have studied the molecular basis of the anticancer actions of resveratrol using human ovarian carcinoma (OVCAR-3) cells. Our findings include the following: (i) nuclear accumulation of COX-2 in resveratrol-treated cells is blocked by the ERK1/2 inhibitor, PD98059; (ii) an inhibitor of COX-2 activity, NS398, prevents accumulation of ERK1/2, COX-2, activated p53 and small ubiquitin-like modifier (SUMO-1) in the nucleus; (iii) apoptosis, quantitated by nucleosome enzyme-linked immunosorbent assay and the nuclear abundance of the pro-apoptotic protein, BcL-xs, were inhibited by NS398. This finding implicates nuclear COX-2 in p53-mediated apoptosis induced by resveratrol. Sumoylation is important to stabilization of p53 and a COX-2-SUMO-1 interaction suggests sumoylation of COX-2 in resveratrol-treated cells and (iv) chromatin immunoprecipitation studies showed binding of induced nuclear COX-2 to the promoter region of PIG3 and Bax, pro-apoptotic gene targets of transcriptionally active p53. Nuclear accumulation of activated ERK1/2 and sumolyated COX-2 are essential to resveratrol-induced pSer-15-p53-mediated apoptosis in human ovarian cancer cells.

Ovarian cancer (OC) is a severe malignancy featuring a poor prognosis due to rapid metastasis and chemotherapy resistance. In this study, we extensively investigated the upstream and downstream mechanisms of miR-548e in regulating OC progression and cisplatin resistance. Our results indicated that ZFAS1 was highly expressed and promoted OC cell proliferation, migration, invasion, and cisplatin resistance by directly suppressing miR-548e expression. ZFAS1 co-localized with miR-548e in the cytosols of OC cells. miR-548e repressed CXCR4 expression, and elevated CXCR4 expression promoted OC cell proliferation, migration, invasion, and cisplatin resistance. Cisplatin resistance induced by ZFAS1 and CXCR4 overexpression in OC cells was mediated by their suppression on let-7a and elevation of BCL-XL/S expression. ZFAS1 knockdown and miR-548e and let-7a overexpression impaired cisplatin resistance and suppressed lung metastatic nodule formation in nude mice. In conclusion, ZFAS1 binds with miR-548e to enhance CXCR4 expression to promote OC cell proliferation and metastasis, which also enhances cisplatin resistance by suppressing let-7a and elevating BCL-XL/S protein expression.

This study manifested that placental HIF-1α and its downstream glucose metabolism effectors can effectively react to hypoxia in EE-induced cholestasis rats. However, hypoxia-induced REDD1 and mTOR alternation, which responds efficiently in normal placentas, was impaired in EE-induced cholestasis placentas.

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