Auro-Liposome miR-195 delivery system impedes ovarian cancer progression and enhances cisplatin-sensitivity

Background: Ovarian cancer (OvCa) accounts for the highest mortality rate among all gynecological malignancy. This is mainly due to late-stage detection, early metastasis and drug-resistance. While most patients initially respond to chemotherapy, Cancer Stem-like Cells (CSCs) facilitate chemoresistance and tumor relapse. WNT7A, a key activator of beta-catenin signaling, is overexpressed in OvCa and promotes CSC characteristics, epithelial-mesenchymal transition (EMT), chemoresistance, whereas the tumor-suppressive miR-195 is downregulated. In this study, we investigated whether restoring miR-195 expression could inhibit cancer progression and improve drug-sensitivity by targeting WNT7A mediated beta-catenin signaling. Methods: CSCs were enriched using anchorage-independent spheroid culture conditions. miR-195 expression levels were assessed by qRT-PCR. Functional assays were performed to determine the effect of miR-195 on CSC markers, EMT, drug-sensitivity. A luciferase reporter assay was utilized to validate the direct miR-195 binding within the WNT7A 3'UTR. beta-catenin activation and nuclear localization were analyzed by immunoblot, immunofluorescence. To mimic tumor microenvironment, multicellular aggregate model was generated using OvCa cell line (A2780-CP20), cancer-associated fibroblast (CAF19) and human microvascular endothelial cells (HMEC1) and for assessing AuLPs's potential as a miR-195 delivery system. Results: Spheroid-derived CSCs displayed enhanced expression of stem cell markers NANOG, OCT4, cMYC, KLF4, accompanied by a significant reduction in miR-195 levels. Restoration of miR-195 expression inhibited spheroid growth, caused downregulation of stemness markers and enhanced cisplatin-sensitivity. miR-195 directly targeted WNT7A, leading to decreased nuclear localization of active beta-catenin and inhibition of WNT/beta-catenin signaling, EMT pathway. Furthermore, in vivo homing assay revealed that stable miR-195 re-expression significantly reduced A2780-CP20 adhesion to the mice omentum, highlighting its anti-metastatic role. Noticeably, our novel AuLPs system conferred superior intracellular delivery of miR-195 compared to commercial agents and more striking inhibition of oncogenic WNT7A/beta-catenin pathway and profound anti-tumor effect against multicellular aggregate. Conclusions: miR-195 suppress OvCa progression by targeting cancer stemness, EMT and enhance cisplatin-sensitivity via directly modulating WNT7A/beta-catenin pathway and formulations of novel AuLPs delivery system offers a promising miRNA-based therapeutic strategy. Acknowledgments: PHF and DOD'S Ovarian Cancer Academy grant (HT94252310772) to SKD.