Absence of p16 gene (CDKN2) deletions in microdissected primary breast carcinoma specimens

Background: The p16 gene (CDKN2), a tumor suppressor gene located on chromosome 9p21, has been demonstrated to be mutated or deleted with high frequency in a variety of tumor cell lines, including breast. While previous studies have not demonstrated CDKN2 mutations in primary breast carcinomas, it is possible that gene deletion in neoplastic DNA was masked by the presence of contaminating normal stromal DNA in breast carcinoma specimens, Methods: We investigated the incidence of homozygous deletion of CDKN2 by analyzing 20 microdissected pure populations of primary breast carcinoma cells. Using polymerase chain reaction (PCR) techniques, the entire coding region and intervening introns of CDKN2 were amplified, The PCR products were resolved by agarose gel electrophoresis and single-strand conformation polymorphism (SSCP) analysis. Results: We detected no deletions or mutations of the p16 gene. Conclusions: CDKN2 is not deleted with high frequency in primary breast carcinomas, and the p16 gene does not play a role in breast carcinogenesis via this mechanism.