Protein Expression Profiles in Pancreatic Adenocarcinoma Compared with Normal Pancreatic Tissue and Tissue Affected by Pancreatitis as Detected by Two-Dimensional Gel Electrophoresis and Mass Spectrometry

Abstract

Pancreatic cancer is a rapidly fatal disease, and there is an urgent need for early detection markers and novel therapeutic targets. The current study has used a proteomic approach of two-dimensional (2D) gel electrophoresis and mass spectrometry (MS) to identify differentially expressed proteins in six cases of pancreatic adenocarcinoma, two normal adjacent tissues, seven cases of pancreatitis, and six normal pancreatic tissues. Protein extracts of individual sample and pooled samples of each type of tissues were separated on 2D gels using two different pH ranges. Differentially expressed protein spots were in-gel digested and identified by MS. Forty proteins were identified, of which five [i.e., ␣-amylase; copper zinc superoxide dismutase; protein disulfide isomerase, pancreatic; tropomyosin 2 (TM2); and galectin-1] had been associated previously with pancreatic disease in gene expression studies. The identified proteins include antioxidant enzymes, chaperones and/or chaperone-like proteins, calcium-binding proteins, proteases, signal transduction proteins, and extracellular matrix proteins. Among these proteins, annexin A4, cyclophilin A, cathepsin D, galectin-1, 14 -3-3, ␣-enolase, peroxiredoxin I, TM2, and S100A8 were specifically overexpressed in tumors compared with normal and pancreatitis tissues. Differential expression of some of the identified proteins was further confirmed by Western blot analyses and/or immunohistochemical analysis. These results show the value of a proteomic approach in identifying potential markers for early diagnosis and therapeutic manipulation. The newly identified proteins in pancreatic tumors may eventually serve as diagnostic markers or therapeutic targets.

Protein Expression Profiling Identifies Cyclophilin A as a Molecular Target in Fhit-Mediated Tumor Suppression

“…On the other hand, cyclophilin A is ubiquitously distributed in tissue, and the cyclophilin A/ cyclosporine A complex has numerous known activities in cell growth, differentiation, transcriptional control, and cell signaling (28). In particular, the cyclophilin A/cyclosporine A complex is known to inhibit calcineurin activity and block cell proliferation; cyclosporine A treatment alone has been reported to inhibit cell proliferation (28,31), but overexpression of cyclophilin A has been reported in human cancers by proteome analyses (32)(33)(34)(35). Indeed, cyclosporine A is unable to inhibit calcineurin activity at high concentrations of cyclophilin A; cyclosporine A treatment induced a G 1 arrest in pancreatic acinar cells, but excess cellular cyclophilin A activates calcineurin (36 *A Z score is estimated when the search result is compared against an estimated random match population.…”

Comparative Proteomics Analysis of Colorectal Cancer

“…Annexins A4 is a member of the annexin superfamily, which can promote membrane fusion and exocytosis, and inhibit phospholipase activity after binding with Ca 2+ , involving in cell signaling, antiapoptotic and other important physiological processes (Miao et al, 2009). It is reported in literature that the expression of AnnexinA4 in pancreatic cancer tissues was significantly higher than that in normal and pancreatitis tissues, indicating AnnexinA4 was related to the development and occurrence of pancreatic cancer (Shen et al, 2004). Annexin A4 is overexpressed in renal cell carcinoma, and immunohistochemical analysis showed altered location Annexin A4 in tumor cells, which is found in the cell membrane and in the cytoplasm, revealing AnnexinA4 may be involved in development and progression (Zimmermann et al, 2004).…”

Cyclophilins contribute to Stat3 signaling and survival of multiple myeloma cells

“…CypA was found to be overexpressed in many cancer cells, including the pancreas (Shen et al, 2004) and non-small cell lung carcinomas, (Howard et al, 2004) and to render cancer cells resistant to hypoxia-induced cell death (Choi et al, 2007). CypA knockdown by siRNAs reduced non-small cell lung tumor growth in vivo (Howard et al, 2005).…”