Abstract 3774: MiR-34b promotes cellular senescence and ROS generation in human cervical cancer cells

Abstract

Background: Cervical cancer is one of the most common cancers in women worldwide, particularly in low- and middle-income countries. Due to low surveillance and late detection, it is one of the major health issues leading to high mortality rates. MicroRNA-34 family (miR-34a, b, c) is thought to be tumor suppressive in several cancers but the mechanistic basis is not clear. Methods: Stable cell lines were generated with inducible hsa-miR-34b lentiviral vector from Dharmacon and maximal time and dose for induction of miR-34b with doxycycline were determined. Cell viability studies on HeLa, SiHa and C33A were investigated by MTT assay. Acridine orange/Ethidium bromide (AO/EB), senescence associated β-galactosidase (SA- β gal) assays for apoptosis and senescence and assessment of DNA damage (γH2AX) were performed. Total reactive oxygen species (ROS), superoxide, hydroxyl and peroxynitrite and H2O2 radicals were quantitated by DCFDA, DHE, HPF dyes and pHyper-dMito plasmid, respectively. Results: Overexpression of miR-34b reduced cell viability in cervical cancer cell lines except SiHa. Further investigation by AO/EB staining revealed no significant increase in the proportion of apoptotic cells on overexpression of miR-34b. Analysis of SA- β gal on overexpression of miR-34b revealed an increase in the proportion of senescent population in all 3 cell lines. Increased DNA damage is also observed in agreement with an increase in cellular senescence. In addition, an increase in oxidative stress was observed in miR-34b overexpressing cell lines as total ROS was elevated in all 3 cell lines with increased superoxide, hydroxyl and peroxynitrite and H2O2 radicals in HeLa and C33A while SiHa showed increased levels of H2O2 radicals with no significant change in other radicals. Conclusions: Overexpression of miR-34b can promote an increase in cellular senescence and oxidative stress in cervical cancer. The differential action in different cell lines may be due to the difference in expression of miR-34b in these cell lines. Our results highlight the potential of miR-34b to be used for therapeutic intervention in cervical cancer. Citation Format: K J Sindhu, Devarajan Karunagaran. MiR-34b promotes cellular senescence and ROS generation in human cervical cancer cells. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3774.