Co-expression analysis of pancreatic cancer proteome reveals biology and prognostic biomarkers
CELLULAR ONCOLOGY
Authors: Mantini, G.; Valles, A. M.; Le Large, T. Y. S.; Capula, M.; Funel, N.; Pham, T., V; Piersma, S. R.; Kazemier, G.; Bijlsma, M. F.; Giovannetti, E.; Jimenez, C. R.
Abstract
Purpose Despite extensive biological and clinical studies, including comprehensive genomic and transcriptomic profiling efforts, pancreatic ductal adenocarcinoma (PDAC) remains a devastating disease, with a poor survival and limited therapeutic options. The goal of this study was to assess co-expressed PDAC proteins and their associations with biological pathways and clinical parameters. Methods Correlation network analysis is emerging as a powerful approach to infer tumor biology from omics data and to prioritize candidate genes as biomarkers or drug targets. In this study, we applied a weighted gene co-expression network analysis (WGCNA) to the proteome of 20 surgically resected PDAC specimens (PXD015744) and confirmed its clinical value in 82 independent primary cases. Results Using WGCNA, we obtained twelve co-expressed clusters with a distinct biology. Notably, we found that one module enriched for metabolic processes and epithelial-mesenchymal-transition (EMT) was significantly associated with overall survival (p = 0.01) and disease-free survival (p = 0.03). The prognostic value of three proteins (SPTBN1, KHSRP and PYGL) belonging to this module was confirmed using immunohistochemistry in a cohort of 82 independent resected patients. Risk score evaluation of the prognostic signature confirmed its association with overall survival in multivariate analyses. Finally, immunofluorescence analysis confirmed co-expression of SPTBN1 and KHSRP in Hs766t PDAC cells. Conclusions Our WGCNA analysis revealed a PDAC module enriched for metabolic and EMT-associated processes. In addition, we found that three of the proteins involved were associated with PDAC survival.
Altered expression of HSPA5, HSPA8 and PARK7 in spinocerebellar ataxia type 17 identified by 2-dimensional fluorescence difference in gel electrophoresis
CLINICA CHIMICA ACTA
Authors: Lee, Li-Ching; Chen, Chiung-Mei; Chen, Fen-Lin; Lin, Pei-Ying; Hsiao, Ya-Chin; Wang, Pin-Rong; Su, Ming-Tsan; Hsieh-Li, Hsiu-Mei; Hwang, Ji-Chuu; Wu, Chung-Hsin; Lee, Guan-Chiun; Singh, Sher; Lin, Yenshou; Hsieh, Sen-Yung; Lee-Chen, Guey-Jen; Lin, Jung-Yaw
Abstract
Background: Expansion of the CAG repeat of the TATA-box binding protein (TBP) gene has been identified as the causative mutations in spinocerebellar ataxia 17 (SCA17). TBP is ubiquitously expressed in both central nervous system and peripheral tissues. The underlying molecular changes of SCA17 are rarely explored. Methods: To study the molecular mechanisms underlying SCA17. we generated stably induced isogenic 293 cells expressing normal TBP-Q(36) and expanded TBP-Q(61) and analyzed the expressed proteins using two dimensional difference in gel electrophoresis (2D-DIGE), followed by mass spectrometry and immunoblotting. Results: Upon induction with doxycycline, the expanded TBP-Q61 formed aggregates with significant increase in the cell population at subG1 phase and cleaved caspase-3. Proteomics study identified a total of 16 proteins with expression changes greater than 1.5 fold. Among the 16 proteins. PARK7, GLRX3, HNRNPA1, GINS1, ENO1, HNRPK and NPM1 are increased. and SERPINA5, HSPA5, VCL, KHSRP, HSPA8, HNRPH1, IMMT, VCP and HNRNPL are decreased in cells expressing TBP-Q61 compared with those expressing TBP-Q(36),. The altered expression of HSPA5, HSPA8 and PARK7 were further validated by 2D and Western immunoblot analyses. Conclusions: The results illustrate the utility of proteomics to identify alterations of proteins which underlie pathogenesis of SCA17, and may serve as potential therapeutic targets. (C) 2008 Elsevier B.V. All rights reserved.