INFREQUENT ALTERATIONS OF THE P16(MTS-1) GENE IN HUMAN GASTRIC-CANCER

p16 (MTS-1, multiple tumor suppressor gene 1), a putative tumor suppre ssor gene, is one of the cyclin-dependent kinase inhibitors (CDI) and it regulates the G1/S transition of the cell cycle. To clarify the rol e of p16 in primary gastric cancer, we have investigated somatic mutat ions of this gene by using the polymerase chain reaction/single strand conformation polymorphism (PCR-SSCP) method. In 23 surgical specimens of primary gastric cancer, none were detected in exon 1 and exon 2. A mong the 6 human gastric cancer cell lines examined, PCR products were not found in 2, MKN28 and MKN45, suggesting the presence of homozygou s deletions. No mutation was found in the other 4 cell lines. Furtherm ore, decreased expression levels were not observed in 13 gastric cance r tissues by reverse transcription PCR (RT-PCR). Considering the above results of PCR-SSCP and RT-PCR, genetic alterations of the p16 gene a re rarely implicated in human gastric cancer tumorigenesis.