透過表觀遺傳重塑克服尿路上皮癌對自然殺手細胞之免疫逃避

              沈正煌¹ 、陳永恩²、希瑪尼·庫瑪麗²、林冠伶²

嘉義基督教醫院泌尿科¹國立中正大學生物醫學系²

Overcoming NK cell evasion in urothelial carcinoma through epigenetic reprogramming

Cheng-Huang Shen¹，Michael W. Y. Chan²，Himani Kumari²，Guan-Ling Lin²

Department of Urology, Ditmanson Medical Foundation Chiayi Christian

Hospital, Chiayi, Taiwan¹ ，Department of Biomedical Sciences, National Chung Cheng University,Min-Hsiung, Chia-Yi, Taiwan²

Background: Urothelial carcinoma (UC), the second most prevalent cancer of the urothelial system, has demonstrated a well-developed ability to evade natural killer (NK) cell-mediated killing via various pathways, highlighting the need for innovative therapeutic approaches. Our study examines the role of cyproheptadine (CPH) and entinostat (ENT) as epigenetic modifiers in enhancing NK cell-mediated cytotoxicity against UC.

Methods: Through our in vitro experiments, UC cells were pre-treated with CPH or ENT and co-cultured with both NK-92 and human primary NK cells in NK cytotoxicity assays to evaluate the NK cell-mediated elimination of UC cells. We also analyzed the epigenetic activation of NKG2D ligands at the promoter region in UC cells and assessed the effects of ectopic expression of ULBP2. Additionally, a syngeneic mouse model using MB49 tumor cells was established to evaluate tumor growth reduction and NK cell infiltration into the tumor microenvironment following CPH or ENT treatments in vivo.

Results:

1. Enhanced NK cell-mediated cytotoxicity: Pre-treatment with CPH or ENT significantly increased NK cell-mediated elimination of UC cells in vitro.
2. Epigenetic activation of NKG2D ligands: This enhancement is attributed to the epigenetic activation of NKG2D ligands, notably through increased H3K27ac enrichment and reduced enrichment of H3K27me3 at the ULBP2 promoter region in UC cells. Furthermore, ectopic expression of ULBP2 in UC cells further augmented their susceptibility to NK cell-mediated killing.
3. In vivo tumor suppression and NK cell infiltration: Our syngeneic mouse model showed that CPH or ENT treatments significantly reduced tumor growth by promoting NK cell infiltration into the tumor microenvironment. This increased infiltration is likely due to elevated levels of the NK-recruiting chemokine CCL3 in drug-treated UC cells.

Conclusion: Collectively, these results underscore the potential of CPH and ENT to suppress tumor growth and enhance immune surveillance by modulating epigenetic pathways that boost NK cell activity, offering promising insights into new strategies for UC treatment.