Abstract 3753: miR-567 modulates the progression of melanoma cells and functions of macrophages

Abstract

Abstract Purpose: Target therapy and immunotherapy are advancements in the treatment of melanoma; unfortunately, a subset of patients does not benefit or produces drug resistance. Therefore, an alternative strategy should be investigated to further improve clinical benefits. Macrophages are the abundant immune cells related to the progression of melanoma and resistance to drugs. In this study, we explored the novel roles of miR-567 in the progression of melanoma and effects of macrophages. Methods: miR-567 expression in nevus and melanoma tissues was analyzed by in situ hybridization. miR-567 was transfected into melanoma cells to investigate its biological effects through functional assays such as proliferation, colony formation, soft agar, and migration assays. In addition, miR-567-related signal transduction pathways in the melanoma cells were studied by western blot and next-generation sequencing analyses. Different phenotypes of macrophages polarized from THP-1 monocyte cells were used as in vitro model to investigate the effects of miR-567 on macrophages. Results: Our results showed that miR-567 expression levels were decreased in melanoma cells compared to melanocyte cells. Consistently, expression of miR-567 was 0.403-fold lower in melanoma tissues (n=118) as compared to nevus tissues (n=40). In addition, the receiver operating characteristic presented that the area under the curve value of miR-567 is 0.9495. Importantly, higher expression of miR-567 enhanced the overall survival of melanoma patients. Overexpression of miR-567 significantly reduced proliferation, survival, anchorage-independent growth, migratory, and invasive abilities of melanoma cells and BRAF-inhibitor resistant cells. Furthermore, our results demonstrated that IGF1R, E2F1, and Cyclin B2 are direct targets of miR-567 and knockdown of these genes attenuated proliferation and survival of melanoma cells. Interestingly, introduction of miR-567 downregulated MAPK/ERK and PI3K/AKT pathways in melanoma cells and regulated multiple pathways related to immune response. Of note, overexpression of miR-567 reduced the promoting melanoma growth induced by M2 or melanoma-associated macrophages, indicating the involvement of miR-567 in regulation of macrophages. Conclusion: miR-567 could be served not only as biomarkers but also as potential molecular target for prevention of melanoma progression. Citation Format: Mai-Huong Thi Nguyen, Chen-Huan Lin, Yu-Chi Huang, Mu-Shiun Tsai, Ming-Hong Chen, Azusa Miyashita, Satoshi Fukushima, Nianhan Ma. miR-567 modulates the progression of melanoma cells and functions of macrophages. [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 3753.