Expression of a new candidate tumor suppressor gene NOEY2 in pancreatic carcinoma

Objective The aim of this study was to disclose the association of NOEY2 with pancreatic carcinoma. Methods Twenty-six human pancreatic carcinoma tissue specimens (23 cases of pancreatic adenocarcinoma, 3 cases of insulinoma), 12 normal pancreatic tissues and 8 human pancreatic carcinoma cell lines (Pu-Pan-1, Miapaca-II. Panc-1 , Cfpac-1, Aapc-1 , BXPC3, HS766T, SW1990) were collected. The final diagnoses of all the cases were confirmed by a senior pathologist. The expression of NOEY2 protein in pancreatic carcinoma and normal pancreatic tissue was detected by immunohistochemistry method, and the expression of NOEY2 protein and mRNA in the cell lines were detected by immunocytochemistry and Northern blot hybridization method. Results (1) NOEY2 protein was expressed in the cytoplasm of normal pancreatic ducts cells, pancreatic acini cells and islet cells. (2) The NOEY2 protein was found in 12/23 pancreatic adenocarcinoma tissues (both carcinoma tissue and adjacent tissue). No NOEY2 protein was detected in 11/23 pancreatic adenocarcinoma tissue, which consisted of two types; NOEY2 protein was detected from 2/11 carcinoma adjacent tissue but not from pancreatic carcinoma tissues, in other 9/11, no NOEY2 protein was detected from pancreatic carcinoma tissues or carcinoma adjacent tissue. (3) The expression of NOEY2 protein was not correlated with the grade of differentiation of pancreatic adenocarcinoma. (4) NOEY2 protein was not found in 3 insulinoma tissue. (5) Neither NOEY2 protein nor mRNA was detected in any of the 8 pancreatic carcinoma cell lines. Conclusions NOEY2 is a possible tumor suppressor gene which may play a role in the pathogenesis of pancreatic carcinoma.