YBX2 modulates mRNA stability via interaction with YTHDF2 in endometrial cancer cells

Abstract

RNA-binding proteins (RBPs) fine-tune gene expression by modulating RNA stability, translation, and degradation. RBPs are involved in the development of endometrial cancer. In particular, Y-box-binding protein 2 (YBX2), a germ cell-specific member of the YBX family, has been reported to maintain cancer stem cell-like phenotypes in endometrial cancer. However, the mechanism by which YBX2 modulates mRNA stability in endometrial cancer cells remains unknown. In this study, we examined the effects of the ectopic expression of YBX2 in endometrial adenocarcinoma-derived Ishikawa cells. We found that elevated levels of YBX2 delayed cell proliferation, without increasing cell apoptosis. Transcriptomic analysis revealed disturbances in gene expression caused by YBX2. Interestingly, heat shock protein family A (Hsp70) member 6 (HSPA6) levels were downregulated due to the reduced mRNA stability after YBX2 binding. YBX2 facilitated the formation of relatively stable cytoplasmic granules in tumor cells via its mRNA binding domain. Moreover, N6-methyladenosine (m6A) reader proteins are recruited by YBX2 granules via the cold-shock domain. Notably, knockdown of YTH N6-methyladenosine RNA-binding protein F2 (YTHDF2), an m6A reader, ameliorated the reduction in HSPA6 mRNA levels induced by YBX2, indicating the synergistic effects of YBX2 and YTHDF2 on mRNA stability. Therefore, YBX2 regulates RNA stability by interacting with the m6A reader proteins.