Down-expression pattern of Ku70 and p53 coexisted in colorectal cancer.

To address the relationship of altered expression of double-strand break repair proteins Ku70 and p53 in clinical colorectal cancer (CRC), we examined the expression pattern of Ku70 and p53 by using fluorescent immunohistochemistry and real-time PCR assays in CRC and pericancerous samples from 152 Chinese patients. The results showed that down-expression pattern of both Ku70 and p53 coexisted in the CRC samples with significant correlating rate (R (2) = 0.9103; P < 0.001), and the down-expression of Ku70 and p53 was significantly associated with the advanced tumor node metastasis stage (Ku70: HR 3.453 in recurrence and 4.182 in survival, P < 0.001; P53: HR 3.114 in recurrence and 4.113 in survival, P < 0.001). The down-regulated Ku70 and p53 were associated with poor disease-free survival. Loss of Ku70 and p53 expression might serve as a biomarker of poor prognosis in CRC patients.