Expression and clinical significance of hedgehog signaling pathway related components in colorectal cancer.

AIM To investigate the expression of three components of the Hedgehog (Hh) signaling pathway (SHH, SMO and GLI1) in human colorectal cancer (CRC) tissues and evaluate their association with clinicopathologic characteristics of the patients. METHODS Fresh tumor tissues and matched tissues adjacent to the tumor were collected from 43 CRC patients undergoing surgery. Normal colorectal tissues from 20 non-CRC cases were also sampled as normal controls. The expression of SHH, SMO, GLI1 mRNAs was assessed by RT-PCR and proteins were detected by immunohistochemical staining. Associations with clinicopathological characteristics of patients were analyzed. RESULTS SHH mRNA was expressed more frequently in tumor tissues than in normal tissues, but the difference did not reach significance in comparison to that in the adjacent tissues. SMO and GLI1 mRNAs were expressed more frequently in tumor tissues than in both adjacent andnormal tissues. The expression intensities of SHH, SMO, GLI1 mRNA in tumor tissues were significantly higher than those in adjacent tissues and normal tissues. Proteins were also detected more frequently in tumors than other tissues. No significant links were apparent with gender, age, location, degree of infiltration or Dukes stage. CONCLUSION Positive rates and intensities of mRNA and protein expression of Hh signaling pathway related genes SHH, SMO, GLI1 were found to be significantly increased in CRC tissues. However, over-expression did not appear to be associated with particular clinicopathological characteristics.