Mechanisms of CRLF3-targeted binding to ACTR2 to promote hepatocellular carcinoma progression and effects on the immune microenvironment.

This study aimed to delve deeper into the effects of CRLF3 on the immune microenvironment and the interaction between CRLF3 and ACTR2 in hepatocellular carcinoma (HCC). CRLF3 and ACTR2 in mouse tumor tissues and HepG2 cells were measured by RT-qPCR and Western Blot. The proliferative ability of HepG2 cells was assessed by MTT and colony formation assays, with apoptosis determined by flow cytometry, and migration and invasion quantified by Transwell assay. The apoptosis rate of CD8⁺ T cells was calculated by flow cytometry, as well as TNF-α and IFN-γ positivity in CD8⁺ T cells. TNF-α, IFN-γ, and IL-2 were assayed by ELISA. The interaction between CRLF3 and ACTR2 was examined using immunoprecipitation and Western Blot experiments. CRLF3 targeted binding to ACTR2 promoted the proliferative and migratory capacities of HepG2 cells and inhibited apoptosis. Lowering CRLF3 inhibited HCC cell immune escape, with a significant increase in TNF-α and IFN-γ-positive populations in CD8⁺ T cells, and enhancing ACTR2 significantly mitigated this effect. Lowering CRLF3 inhibited HCC xenografted tumor growth in nude mice. Through its targeted binding to ACTR2, CRLF3 aids in the growth and immune escape of HCC cells.