AbstractBACKGROUNDCurrently, pancreatic adenocarcinoma is the fourth leading cause of cancer‐related death in the United States. Despite the advances in pancreatic carcinoma research, patients with this devastating disease have a very poor prognosis. To identify the gene expression profile of pancreatic carcinoma, an important step in the process of developing new diagnostic and therapeutic strategies, the authors investigated the alteration of gene expression in this disease.METHODSThe authors analyzed a public serial analysis of gene expression (SAGE) database and examined in greater detail the expression of synuclein‐γ mRNA in several pancreatic carcinoma cell lines and tumor tissue samples by reverse transcriptase–polymerase chain reaction (RT‐PCR) analysis and Northern blot analysis. The expression of synuclein‐γ protein was investigated further by immunohistochemical and Western blot analyses using tumor cell lines, tumor tissue, and serum samples.RESULTSSynuclein‐γ mRNA was overexpressed in 11 of 12 pancreatic carcinoma cell lines, including AsPc‐1, MDAPanc28, Capan‐1, Capan‐2, PANC‐1, HS766T, MDAPanc3, MDAPanc48, Colo357FG, MiaPaCa2, CFPac1, and BxPc3. The expression of synuclein‐γ protein was detectable in 8 of 12 pancreatic carcinoma cell lines (67%) and in 22 of 32 pancreatic tumor tissue samples (69%) by Western blot analysis. On immunohistochemical staining, synuclein‐γ protein was present in 61% of the tumor tissue samples examined from patients with Stage I and II pancreatic carcinoma. The overexpression of synuclein‐γ is correlated with perineural and lymph node invasion. Synuclein‐γ protein also was detectable by Western blot in serum samples from 21 of 56 patients (38%) with pancreatic carcinoma.CONCLUSIONSSynuclein‐γ, which initially was described as a breast carcinoma–specific gene involved in invasion, metastasis, and chemotherapy resistance, was frequently overexpressed in pancreatic carcinoma. Overexpression of synuclein‐γ may play a role in pancreatic carcinoma invasion. Further studies will be necessary to determine the role of synuclein‐γ in pancreatic carcinoma. Cancer 2004. © 2004 American Cancer Society.