MOLECULAR DIAGNOSIS OF P53 MUTATIONS IN GASTRIC-CARCINOMA BY TOUCH PREPARATION

Thirty-one tumor samples from selected cases of gastric carcinoma were analyzed for mutations of the p53 tumor suppressor gene. Template DNA was prepared according to the touch preparation procedure, which allo wed us to isolate clusters of neoplastic cells out of a stromal cellul ar background to be used as a template in the amplification of target exons of the p53 locus. In our present study, by polymerase chain reac tion/single strand conformation polymorphism analysis we give evidence of p53 mutations occurring in the DNA-binding core domain of the prot ein (exons 5 through 9), which are clustered in stages III and IV of t he disease (six mutations out of seventeen samples; 35%). No p53 mutat ions were detected in fourteen gastric cancer samples at I and II stag es. Beside the use of conventional molecular scanning procedures, our study proposes the application of the touch preparation method to incr ease the detection of genetic alterations in human solid tumors.