Original Article
Copyright ©2009 The WJG Press and Baishideng. All rights reserved.
World J Gastroenterol. Oct 28, 2009; 15(40): 5035-5043
Published online Oct 28, 2009. doi: 10.3748/wjg.15.5035
Expression of γ-synuclein in colorectal cancer tissues and its role on colorectal cancer cell line HCT116
Qing Ye, Bo Feng, Yuan-Fei Peng, Xue-Hua Chen, Qu Cai, Bei-Qin Yu, Liang-Hui Li, Ming-Yuan Qiu, Bing-Ya Liu, Min-Hua Zheng
Qing Ye, Bo Feng, Yuan-Fei Peng, Liang-Hui Li, Ming-Yuan Qiu, Min-Hua Zheng, Department of General Surgery, Ruijin Hospital, Shanghai Jiaotong University School of Medicine; Shanghai Minimally Invasive Surgery Center, Shanghai 200025, China
Qing Ye, Bo Feng, Yuan-Fei Peng, Xue-Hua Chen, Qu Cai, Bei-Qin Yu, Liang-Hui Li, Ming-Yuan Qiu, Bing-Ya Liu, Min-Hua Zheng, Shanghai Institute of Digestive Surgery, Shanghai 200025, China
Author contributions: Ye Q designed and performed the research, including performance of colony formation assay, cell migration and invasion assay and writing the paper; Feng B participated in designing the research and carried out immunohistochemistry; Peng YF performed isolation of RNA and protein, and carried out western blotting and CCK8 assay; Chen XH cultured cells, and carried out selection of stable transfectants; Cai Q carried out real-time quantitative RT-PCR; Yu BQ carried out plasmid construction; Li LH and Qiu MY collected tissue samples and clinicopathological data used in the study; Liu BY contributed vital reagents and analytical tools; Zheng MH took responsibility for financial support, and obtaining permission from all coauthors for the submission of any version of the paper and for any changes in authorship.
Correspondence to: Min-Hua Zheng, Professor, Shanghai Institute of Digestive Surgery, No. 197 Ruijin Second Road, Shanghai 200025, China. yqbobo@163.com
Telephone: +86-21-64458887 Fax: +86-21-64333548
Received: August 7, 2009
Revised: September 9, 2009
Accepted: September 15, 2009
Published online: October 28, 2009

AIM: To investigate the expression pattern of γ-synuclein in colorectal cancer (CRC) tissues, and to study the effects of γ-synuclein on CRC cell line HCT116 biological features in vitro.

METHODS: The expression pattern of γ-synuclein was determined in 54 CRC tissues and 30 tumor-matched nonneoplastic adjacent tissues (NNAT) 5 cm away from the tumor via real-time quantitative reverse transcription PCR (RT-PCR) and immunohistochemistry. The relationship between γ-synuclein protein expression and clinicopathological factors of CRC tissues was analyzed. Three small interfering RNA (siRNA) targeting γ-synuclein mRNA plasmids were constructed and transfected into the CRC cell line HCT116. The stable cell lines were selected with G-418 for 28 d, and the biological features of these cells were examined by cell growth curve, soft agar assay, and cell migration and invasion assays in vitro.

RESULTS: The expression of γ-synuclein mRNA and protein was much higher in CRC tissue samples than in NNAT samples (P = 0.02, P = 0.036). There was a significant correlation between the γ-synuclein protein expression and clinical stage and lymph node involvement of CRC (P = 0.02, P = 0.033). In functional analysis we found that down-regulation of γ-synuclein expression in HCT116 cells could inhibit the growth, colony formation rate, and migration and invasion ability of HCT116 cells.

CONCLUSION: Increased expression of γ-synuclein in CRC tissues and the biological effects of reduced γ-synuclein expression on HCT116 cells suggest that γ-synuclein may play a positive role in the progression of CRC.

Keywords: γ-synuclein, Colorectal cancer, Expression, Cell proliferation, Colony formation, Migration, Invasion