Identification and functional validation of caldesmon as a potential gastric cancer metastasis-associated protein.

Abstract

In this study, we aim to identify biomarkers for gastric cancer metastasis using a quantitative proteomics approach. The proteins extracted from a panel of 4 gastric cancer cell lines, two derived from primary cancer (AGS, FU97) and two from lymph node metastasis (AZ521, MKN7), were labeled with iTRAQ (8-plex) reagents and analyzed by 2D-LC-MALDI-TOF/TOF MS. In total, 641 proteins were identified with at least a 95% confidence. Using cutoff values of >1.5 and <0.67, 19 proteins were found to be up-regulated and 34 were down-regulated in the metastatic versus primary gastric cancer cell lines respectively. Several of these dysregulated proteins, including caldesmon, were verified using Western blotting. It was found that caldesmon expression was decreased in the two metastasis-derived cell lines, and this was confirmed by further analysis of 7 gastric cancer cell lines. Furthermore, immunohistochemical staining of 9 pairs of primary gastric cancer and the matched lymph node metastasis tissue also corroborated this observation. Finally, knockdown of caldesmon using siRNA in AGS and FU97 gastric cancer cells resulted in an increase in cell migration and invasion, while the overexpression of caldesmon in AZ521 cells led to a decrease in cell migration and invasion. This study has thus established the potential role of caldesmon in gastric cancer metastasis, and further functional studies are underway to delineate the underlying mechanism of action of this protein.

• Authors: Qian Hou, Hwee Tong Tan, Kiat Hon Lim, Teck Kwang Lim, Avery Khoo, Iain B H Tan, Khay Guan Yeoh, Maxey C M Chung
• Journal: Journal of proteome research (J Proteome Res) Vol. 12 Issue 2 Pg. 980-90 (Feb 01 2013) ISSN: 1535-3907 [Electronic] United States
• PMID: 23265641 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Biomarkers, Tumor
• Calmodulin-Binding Proteins
• Neoplasm Proteins
• RNA, Small Interfering

Topics

• Biomarkers, Tumor (antagonists & inhibitors, genetics, metabolism)
• Blotting, Western
• Calmodulin-Binding Proteins (antagonists & inhibitors, genetics, metabolism)
• Cell Line, Tumor
• Cell Movement
• Gene Expression Profiling
• Gene Expression Regulation, Neoplastic
• Gene Knockdown Techniques
• Humans
• Immunohistochemistry
• Lymphatic Metastasis (diagnosis, genetics)
• Neoplasm Proteins (genetics, metabolism)
• RNA, Small Interfering (genetics)
• Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
• Stomach Neoplasms (diagnosis, genetics, metabolism)