DDX18 influences chemotherapy sensitivity in colorectal cancer by regulating genomic stability.

Chromosomal Instability (CIN) encompasses approximately 65% to 70% of colorectal cancer (CRC) patients, playing a pivotal role in tumor progression. However, controversies persist regarding the molecular characteristics and treatment strategies associated with these patients. Integrative colorectal cancer proteogenomic analysis identified DDX18 in colorectal cancer. We investigated the molecular mechanisms underlying the regulation of colorectal cancer by the R-loop binding protein DDX18 using colon cancer tissues, cell lines and patient-derived organoids. Our findings revealed that DDX18 expression positively correlates with the expression of genomic instability marker R-loops. Moreover, heightened DDX18 expression delays the completion of DNA damage repair, leading to an increase in double-strand DNA breaks, thereby promoting genomic instability. Notably, the upregulation of DDX18 enhances sensitivity to DNA-damaging. This study elucidated DDX18 beyond participating in fundamental physiological functions, may play a crucial role in the regulation of genomic stability, and also provides a powerful resource for further functional exploration of DDX18 in cancer progression and therapeutic application.