Deletion of the FHIT gene in human colorectal cancer is independent of high-risk HPV infection.

Abstract

The fragile histidine triad (FHIT) gene, which is frequently lost in many cancers, has been identified as a candidate tumor suppressor gene at chromosome 3p locus 14.2. Human papillomaviruses (HPVs) are the major cause of cervical carcinoma and have been found to be able to integrate its genes into the chromosome 3 fragile site of cultured cells, deleting a piece of DNA which includes the FHIT gene. We used nested reverse transcriptase PCR and DNA sequencing to evaluate 32 cases of colorectal adenocarcinoma and matched nearby normal tissues for aberrant transcripts of FHIT and infection of high-risk HPVs. Aberrant transcripts of the FHIT gene were observed in 34.4% of colorectal adenocarcinoma and in 6.3% of matched nearby normal tissues. The HPV(16) DNA was detected in 21.9% of colorectal adenocarcinomas and 3.1% of matched nearby normal tissues using PCR. Only two cases of colorectal adenocarcinoma contained both aberrant transcripts of FHIT and HPV(16) infection. No HPV(18) infection was detected in the present study. Our results indicate that alteration of the FHIT gene and HPV(16) infection are important genetic events associated with colorectal adenocarcinoma. However, there is no correlation between FHIT abnormalities, clinicopathological features, and HPV(16) infection in colorectal adenocarcinoma.