Paper Title
Induction of Apoptosis in Hela Cervical Cancer Cells by P. Longifolia Leaf Extract through Downregulation of MIR-221-5P

Abstract
Background: Cervical cancer is one of the most diagnosed cancers and leading cause of death among women. The evolution of microRNA and its role in the regulation of various biological activities lead to the break thorough of miRNA-based therapeutic approaches. Our recent study showed that Polyalthia longifolia methanolic leaf extract (PMLE) induced apoptosis through microRNA dysregulation in HeLa cervical cancer cells. This study would contribute to illustrate the functional analysis of miR-221-5p in relation to PMLE treatment in HeLa cells with scientific evidence. Methods: The PMLE was prepared by maceration method and MTT assay was incorporated to determine the IC50 value of the plant extract in HeLa cells. Over-expression and knock down of miR-221-5p in HeLa cells were performed by transfection of miR-221-5p mimic and anti-miR-221-5p respectively. Annexin V/Pi analysis and Caspase 3 analysis was performed to study the functional analysis of miR-221-5p in HeLa cells. Ultra-morphological study was performed through SEM and TEM. Results: Annexin V/Pi analysis and Caspase 3 analysis revealed the induction of apoptosis in anti-miR-221-5p transfected cells in relation to P. longifolia treatment. Besides, ultra-morphological studies through SEM and TEM showed significant apoptotic hallmarks in anti-miR-221-5p transfected HeLa cells as compared to that of in untreated and miR-221-5p over-expressed cells. Conclusion: Based on this study, it can be deduced that PMLE exert an excellent cytotoxicity on cancerous cells through the down-regulation of miR-221-5p, thus indicating the leaf extract of P. longifolia is a promising anti-cancer drug candidate. Acknowledgement: This project was funded by the Bridging Grant (Grant No.: 203/CIPPM/6316068) from the Universiti Sains Malaysia, Malaysia. Author is supported by Graduate Assistant Scheme, Universiti Sains Malaysia. Keywords - Polyalthia longifolia, microRNA, Cervical Cancer, Apoptosis, Anti-Cancer Drug