Full Length Research Paper

Refined mapping of loss of heterozygosity in Chinese sporadic gastric carcinoma

Quan Wang¹, Yu-Gang Wen¹, Da-Peng Li¹, Fei Huang¹, Chong-Zhi Zhou¹, Guo-Qiang Qiu¹, Hua-Mei Tang² and Zhi-Hai Peng¹*

¹Department of General Surgery, Shanghai First People's Hospital, College of Medicine, Shanghai Jiao Tong University, China.

²Department of Pathology, Shanghai First People's Hospital, College of Medicine, Shanghai Jiao Tong University, China.

*Corresponding author. Email: pengpzh@hotmail.com.Tel: +86-21-63240090-3132.

Fax: +86-21-63241377.

Abbreviations: TSGs, Tumor suppression genes; PCR, polymerase chain reaction; NCBI, national centre for biotechnology information; LOH, loss of heterozygosity; GDB, genome database.

Accepted 27 July, 2010

   Abstract

The aim of this study is to explore precise deleted regions where the candidate tumor suppressor genes might be located in Chinese sporadic gastric carcinoma. By searching in Genothon, NCBI and GDB databases, 145 polymorphic microsatellite markers were chosen, at a mean density of approximately one marker every 2 - 4 cM, covering 15 chromosomes. These polymorphic microsatellite markers in gastric carcinoma and adjacent tissue were analyzed via PCR. PCR products were submitted to electrophoresis on an ABI 3730 DNA sequencer. Genemapper3.2 software was used for LOH (Loss of Heterozygosity) scanning and analysis. Comparison between LOH frequency and clinicopathological factors was performed by Fisher’s exact test. 26 refined regions were mapped as candidate regions for TSGs (Tumor suppression genes) in Chinese sporadic gastric cancer. Associations between LOH and clinical information indicated that 6 loci was associated with pTNM stage, 5 with Lauren's type, 4 with lymph nodes metastasis and another 2 with distant metastasis. Through refined deletion mapping, 26 candidate regions, where TSGs may be located, were found and 17 loci were proposed to be used as clinical markers in Chinese sporadic gastric cancer.

Key words: Gastric carcinoma, refined mapping, loss of heterozygosity (LOH), tumor suppressor genes (TSGs), tumor markers.