Coexistence of K-ras mutations and HPV infection in colon cancer

BMC Cancer. 2006 May 4;6:115. doi: 10.1186/1471-2407-6-115.

Abstract

Background: Activation of the ras genes or association with human papillomavirus infection have been extensively studied in colorectal cancer. However, the correlation between K-ras mutations and HPV in colorectal cancer has not been investigated yet. In this study we aimed to investigate the presence of K-ras mutations and their correlation with HPV infection in colon cancer.

Methods: K-ras mutations were analyzed by a mutagenic PCR assay and digestion with specific restriction enzymes to distinguish the wild-type and mutant codons. HPV infection was analyzed by PCR amplification and hybridization with specific probes by Southern blotting. Statistical analyses were performed by the chi-square and Fisher's exact tests

Results: HPV gene fragments were detected in 43 tumors and 17 normal tissue samples. HPV 18 was the prevalent type in the tumor tissue. A mutation at codon 12 of the K-ras gene was present in 31 patients. 56% of the HPV-positive tumors also harbored a K-ras mutation. Codon 13 mutations were not observed. These data indicate that infection with high risk HPV types and mutational activation of the K-ras gene are frequent events in colorectal carcinogenesis.

Conclusion: Our findings suggest that mutational activation of the K-ras gene is a common event in colon carcinogenesis and that HPV infection may represent an important factor in the development of the premalignant lesions leading to the neoplastic phenotype.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Colonic Neoplasms / genetics*
  • Colonic Neoplasms / virology*
  • Genes, ras*
  • Humans
  • Mutation*
  • Papillomaviridae
  • Papillomavirus Infections / complications*