YTHDC1 affects the ubiquitination level of RAD51 by negatively regulating UBE3A expression and inhibits colorectal cancer cells apoptosis

Understanding the role of YTHDC1 in colorectal cancer development and DNA damage repair is crucial for advancing treatment strategies. In our study, we found that YTHDC1 is expressed at significantly higher levels in high-malignancy tissues compared to low-malignancy tissues. Silencing YTHDC1 effectively inhibits the proliferation of colorectal cancer cell lines and significantly increases cell apoptosis. We identified RAD51 as a key downstream target of YTHDC1. Knockdown of YTHDC1 reduced RAD51 protein levels, while silencing RAD51 also inhibited cancer cell proliferation. Interestingly, RNA sequencing indicated that YTHDC1 deletion did not affect RAD51 transcription but increased its ubiquitination through WB experiment. Our analysis revealed that reducing YTHDC1 raised E3 ligase UBE3A levels, which is involved in RAD51 ubiquitination and ubiquitination experiments confirmed that RAD51 is one of the ubiquitination substrates of UBE3A. Co-immunoprecipitation experiments confirmed interactions among YTHDC1, UBE3A, and RAD51, suggesting they form a complex that regulates homologous repair processes. Our study provides new insights into how YTHDC1 modulates RAD51 ubiquitin levels through post-translational modifications, offering valuable information for developing effective colorectal cancer therapies. Overall design: In order to investigate the role of YTHDC1 in colorectal cancer, we utilized siRNA to knock down YTHDC1 in two different colorectal cancer cell lines in vitro, HCT116 and SW480.