title: KLF4 Expression Correlates with the Degree of Differentiation in Colorectal Cancer.
abstract: OBJECTIVE
  Krüppel-like factor 4 (KLF4) is an epithelial-specific transcription factor primarily expressed in the gastrointestinal tract that mediates growth arrest in the colonic epithelium. We tried to find whether KLF4 expression is associated with the progression and differentiation of colorectal cancer.
  
  
  METHODS
  We detected KLF4 expression in 109 colorectal specimens (40 normal appearing mucosa, 7 adenomas, and 62 carcinomas) by immunohistochemistry using a tissue microarray. Western blot and RT-PCR analyses were also performed.
  
  
  RESULTS
  The upregulation of KLF4 expression in carcinoma tissue was statistically significant (p<0.05) when compared to normal appearing mucosa. The negative and weak positive staining rates in normal appearing mucosa, adenoma, and carcinoma were 42.5%, 71.4%, and 82.3%, respectively, indicating a decreased degree of KLF4 expression over the course of progressive transformation of normal cells into malignant derivatives. KLF4 protein levels showed no correlation with sex, age, or metastatic state (p>0.05), while KLF4 protein expression correlated with the diagnostic stage (p<0.05). Furthermore, strong KLF4 staining was detected in 22.9% (11/48) and 0% (0/14) of well/moderately and poorly differentiated colorectal cancers, respectively. Our results clearly indicate that KLF4 protein expression significantly correlates with the degree of differentiation in colorectal cancers (p<0.05). KLF4 expression in RKO cells is also upregulated by butyrate, an inducer of differentiation.
  
  
  CONCLUSIONS
  Downregulation of KLF4 expression may lead to more poorly differentiated tumors.
authors.affiliation: Institute of Clinical Pharmacology and Key Laboratory of Anti-Inflammatory and Immune Pharmacology, Hefei, China.
authors.forename: Ruolei
authors.initials: R
authors.lastname: Hu
authors.forename: Yan
authors.initials: Y
authors.lastname: Zuo
authors.forename: Li
authors.initials: L
authors.lastname: Zuo
authors.forename: Chao
authors.initials: C
authors.lastname: Liu
authors.forename: Sumei
authors.initials: S
authors.lastname: Zhang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wu
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhou
authors.forename: Shuyu
authors.initials: S
authors.lastname: Gui
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
authors.forename: Yuan
authors.initials: Y
authors.lastname: Wang