Aberrant expression of krüppel-like factor 6 protein in colorectal cancers

Aim: To investigate whether krÜppel-like factor 6 (KLF6) plays an important role in the development and/or progression of colorectal cancer. Methods: A total of 123 formalin-fixed and paraffin-embedded colorectal cancer specimens were analyzed by immunohistochemistry using tissue microarray for the expression of KLF6 protein. The specimens were collected over a 3-year period in the laboratories at our large teaching hospital in Seoul, Republic of Korea. The correlation of KLF6 expression with clinicopathologic parameters was analyzed by χ² test and Bartholomew test. Results: Normal colonic epithelium showed weak to moderate expression of KLF6, whereas reduced KLF 6 expression or loss of KLF6 expression was seen in 45 (36.6%) of the 123 colorectal carcinoma specimens. Interestingly, aberrant expression of KLF6 was detected in 25 (43.1%) of 58 cases with metastasis to regional lymph node and in 31 (47.0%) of 66 tumors more than 5 cm in size. Statistically, loss of KLF6 expression was significantly associated with tumor size (P<0.05). However, there was no significant correlation between KLF6 expression and Dukes' stage (Bartholomew test, P>0.05), tumor location and lymph node metastasis (χ² test, P> 0.05). Conclusion: Loss of KLF6 expression may be a common and early event in colorectal carcinogenesis.