Mir-29b Regulates Oxidative Stress by Targeting SIRT1 in Ovarian Cancer Cells

Abstract

Background: Metabolic abnormalities are frequently observed in multiple malignancies including epithelial ovarian cancer (EOC), among which imbalance between generation and elimination of reactive oxygen species (ROS) plays a critical role in EOC onset and progression. Here we investigated the role of miR-29b, a well-established tumor-suppressor miRNA in metabolic regulation of EOC cells. Methods: cell viability and apoptosis in miR-29b inhibited and over-expressed EOC cells were evaluated by CCK8 and Annexin V–FITC/PI assays. Change in miR-29b was detected in EOC cells incubated in H₂O₂ culture by q-PCR. Relative ROS levels were also detected in different EOC cultures, including modified miR-29b and SIRT1 levels as well as H₂O₂ incubation. A luciferase reporter assay was employed to detect the direct binding of miR-29b to SIRT1 3’ UTR. Changes in cell viability and ROS levels were assessed in SIRT1-knocked down EOC cells. Results: miR-29b expression correlates with decreased EOC cell viability and increased apoptosis. H₂O₂ downregulated miR-29b in a time and dose-dependent manner. miR-29b expression negatively correlated with ROS levels, whereas SIRT1 significantly stimulated ROS formation. Luciferase reporter assays confirmed miR-29b downregulation of SIRT1by directly targeting its mRNA 3’-UTR. SIRT1 silencing rescues cell viability of H₂O₂ treated cells. Also, SIRT1 inhibition blocked cell apoptosis induced by H₂O₂ as well as reduced intracellular ROS levels. Conclusion: Together, our findings indicated that the miR-29b/SIRT1 axis has a protective effect against H₂O₂-induced damage of cell viability and oxidative stress and may provide novel options for miR-29b-based therapeutic approaches for EOC treatment.

C5a induces A549 cell proliferation of non-small cell lung cancer via GDF15 gene activation mediated by GCN5-dependent KLF5 acetylation

“…The pGL3-GDF15-FL and truncated 1 to 4 plasmids were transfected into A549 cells. The promoter activity was measured by dual-luciferase reporter reagent [47]. …”

A new SIRT1 inhibitor, MHY2245, induces autophagy and inhibits energy metabolism via PKM2/mTOR pathway in human ovarian cancer cells

“…SIRT1 is over-expressed in a majority of ovarian cancers [13,14], implying a role of SIRTs in ovarian tumorigenesis. HighexpressionofSIRT1isalso associated with malignant transformation of human ovarian tissue [15] and with ovarian carcinoma with poor prognosis [16]. Therefore, SIRT1 inhibition appears to be a good strategy to overcome cancer drug resistance and improve therapy.…”

miRNAs, oxidative stress, and cancer: A comprehensive and updated review

“…In addition, in the ovarian cancer cells treated with H 2 O 2 , miR‐29b levels are decreased, which confirms the involvement of this miRNA in oxidative stress‐dependent activities. The expression level of miR‐29b is negatively correlated with the ROS level, while the SIRT1 strongly stimulates the ROS production (Hou, Zuo, Li, Zhang, & Teng, 2017). The miR‐200 family (miR‐200a and miR‐141) is another category of miRNAs involved in the oxidative condition that modulate oxidative stress responses by targeting the P38α gene (Mateescu et al, 2011).…”