KLF4 inhibits colorectal cancer cell proliferation dependent on NDRG2 signaling.

Krüppel-like factor 4 (KLF4) is a zinc finger transcription factor, which was confirmed as a tumor suppressor gene in colorectal cancers. KLF4 inhibits colorectal cancer cells proliferation through upregulating p21WAF1/Cip1 and downregulating cyclin D1. We firstly reported that N-Myc downstream regulated gene 2 (NDRG2) was a novel tumor suppressor gene in multiple cancers, such as glioma, breast cancer and colorectal cancer. Herein, we provide novel evidence that KLF4 can transcriptionally activate NDRG2 by binding with NDRG2 promoter. With MTT assay, EdU staining, colony formation assay and xenograft mouse model, we confirmed that KLF4 inhibited colorectal cancer cell proliferation and tumorigenesis dependent on NDRG2. Finally, with tissue array analysis, we found a positive correlation of combined detection of KLF4/NDRG2 co-expression with TNM grades and differentiation levels of colorectal cancer. Lower expression of KLF4 and NDRG2 in colorectal cancer patients was correlated with poor overall survival. Thus, KLF4 inhibited the proliferation of colorectal cancer cells dependent on NDRG2 signaling, which provides a novel strategy for therapy and early diagnosis of colorectal cancer.