[Detection of H-ras and K-ras in tumors of gastrointestinal-pancreatic system].

The Gastro-Entero-Pancreatic System (GEP) defined a group of highly differentiated neuroendocrine tumors (Insulinomas, Gastrinomas, PP-omas, Somatostatinomas, Carcinoids). In this kind of tumors the multistage carcinogenesis is really unknown. Activated ras oncogenes could play an important role in initiation or process of carcinogenesis in different human cancers. The purpose of our study was to determe if H-ras or K-ras play a role in the carcinogenesis of GEP tumors. 20 paraffin embedded tumor tissues (1 Vipom, 1 Somatostatinom, 10 Carcinoids, 1 Gastrinoma, 4 livermetastasis of a Carcinoid, 3 Insulinomas) were analysed immunohistologic of H-ras and K-ras oncogene protein expression. Immunohistologic investigations showed a H-ras expression in 65% (13/20). K-ras protein could detected in 10% (2/20). On the basis of these data H-ras oncogene expression could play a role in the multistage carcinogenesis of GEP tumors.