Tumor-suppressive role of Kruppel-like factor 4 (KLF-4) in colorectal cancer.
Kruppel-like factors (KLFs) are a group of transcriptional regulators that have recently been identified to exhibit tumor-suppressive function against various gastrointestinal cancers. The present study aims to investigate the expression patterns and prognostic value of KLF-4 in colorectal cancers (CRCs). KLF-4 levels in CRC tissues were examined via immunohistochemistry analysis, real-time quantitative polymerase chain reaction, and western blotting. The chi-square test was performed to evaluate the correlation between KLF-4 expression and the clinicopathological characteristics. Kaplan-Meier analysis was performed to assess the prognostic value of KLF-4 in CRC patients. In addition, we evaluated the effect of KLF-4 knockdown on the proliferation of CRC HT-29 cells. Our results showed significant downregulation of KLF-4 in 31 CRC samples, collected from CRC patients showing more malignant characteristics such as lymphatic metastasis, low tumor cell differentiation, and tumor recurrence. CRC patients in the low KLF-4 group were found to have reduced overall survival and decreased disease-free survival time. Moreover, HT-29 cells transfected with siRNA-KLF-4 showed increased proliferation compared to those transfected with control siRNA. In summary, lower KLF-4 expression was correlated with malignant CRC status and poor prognosis in CRC patients. Moreover, KLF-4 suppression promoted the proliferation of CRC cells in vitro. These results provide novel insights into the tumor suppressive role of KLF-4 in CRC.