P53 MUTATIONS ARE COMMON IN PANCREATIC-CANCER AND ARE ABSENT IN CHRONIC-PANCREATITIS

Pancreatic expression of the p53 tumor suppressor gene was studied in pancreatic adenocarcinomas and chronic pancreatitis. By immunohistoche mistry, 16 of 34 (47%) cancers and none of the 24 chronic pancreatitis samples revealed nuclear staining. Sequence analysis indicated that 8 of 24 (33%) cancers were mutated for the p53 gene. Point substitution s occurred at codons 35, 105, 133, 213, 213, 258, and 299. A three bas e-pair in-frame insertion was identified between codons 261 and 262. N one of 8 chronic pancreatitis samples exhibited p53 gene mutations. Th ese data support a role for p53 gene alterations in human pancreatic c ancer, and suggest that loss of its regulatory functions may constitut e one of the differences between pancreatic cancer and chronic pancrea titis.