DPC4 GENE IN VARIOUS TUMOR TYPES

We recently identified a novel tumor-suppressor gene, DPC4, at chromos ome 18q21.1 and found that both alleles of DPC4 were inactivated in ne arly one-half of the pancreatic carcinomas, Here, we analyzed 338 tumo rs, originating from 12 distinct anatomic sites, for alterations in th e DPC4 gene, Sixty-four specimens were selected for the presence of th e allelic loss of 18q and were further analyzed for DPC4 sequence alte rations, An alteration of the DPC4 gene sequence was identified in one of eight breast carcinomas and one of eight ovarian carcinomas, These results indicate that whereas DPC4 inactivation is prevalent in pancr eatic carcinoma (48%), it is distinctly uncommon (<10%) in the other t umor types examined, The tissue restriction of alterations in DPC4, as in many other tumor-suppressor genes, emphasizes the complexity of ra te-limiting checkpoints in human tumorigenesis.