Gastric Cancer
Copyright ©The Author(s) 2003. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Aug 15, 2003; 9(8): 1662-1666
Published online Aug 15, 2003. doi: 10.3748/wjg.v9.i8.1662
Growth, invasion, metastasis, differentiation, angiogenesis and apoptosis of gastric cancer regulated by expression of PTEN encoding products
Hua-Chuan Zheng, Yi-Ling Li, Jin-Min Sun, Xue-Fei Yang, Xiao-Han Li, Wei-Guo Jiang, Yin-Chang Zhang, Yan Xin
Hua-Chuan Zheng, Jin-Min Sun, Xue-Fei Yang, Yin-Chang Zhang, Yan Xin, Lab. 4, Cancer Institute, The First Affiliated Hospital of China Medical University, Shenyang 110001, Liaoning Province, China
Yi-Ling Li, Department of Digestive Diseases, The First Affiliated Hospital of China Medical University, Shenyang 110001, Liaoning Province, China
Xiao-Han Li, Wei-Guo Jiang, Department of Pathology, The Second Affiliated Hospital of China Medical University, Shenyang 110004, Liaoning Province, China
Author contributions: All authors contributed equally to the work.
Correspondence to: Hua-Chuan Zheng, Lab. 4, Cancer Institute, The First Affiliated Hospital of China Medical University, Shenyang 110001, Liaoning Province, China. zheng_huachuan@hotmail.com
Telephone: +86-24-23256666 Ext 6351 Fax: +86-24-23253443
Received: March 5, 2003
Revised: March 12, 2003
Accepted: March 29, 2003
Published online: August 15, 2003
Abstract

AIM: To investigate expression of PTEN in gastric cancer and to explore its roles in tumorigenesis and progression of gastric cancer.

METHODS: Formalin-fixed and paraffin-embedded tissues of adjacent non-tumor mucosa and primary foci from 113 cases of gastric cancers were studied for the expression of PTEN and Caspase-3 and microvessel density (MVD) by streptavidin-peroxidase (S-P) immunohistochemistry with antibodies against PTEN, Caspase-3, and CD34. The relationship between PTEN and Caspase 3 expression and clinicopathological parameters of tumors was compared.

RESULTS: Primary gastric cancer cells expressed PTEN less frequently than adjacent epithelial cells of primary foci (54.9% vs 89.4%; P = 0.000, χ2 = 33.474). PTEN expression was significantly associated with invasive depth (P = 0.003, rs = 0.274), metastasis (P = 0.036, rs = 0.197), growth pattern (P=0.008, rs = 0.282), Lauren’s classification (P = 0.000, rs = 0.345), and histological classification (P = 0.005, rs = 0.262) of tumors, but not with tumor size (P = 0.639, rs = 0.045), Borrmann’s classification (P = 0.544, rs = 0.070) or TNM staging (P = 0.172, rs = 0.129). PTEN expression was negatively correlated with MDV in primary gastric cancer (P = 0.020, F = 5.558). Primary gastric cancer cells showed less frequent immunoreactivity to Caspase-3 than adjacent epithelial cells of primary foci (32.7% vs 50.4%; P = 0.007, χ2 = 7.286). Caspase-3 expression was dependent of PTEN expression in primary gastric cancer cells (P = 0.000, χ2 = 15.266).

CONCLUSION: Down-regulated expression of PTEN plays an important role in tumorigenesis, progression, growth, differentiation and angiogenesis of gastric cancer. Low expression of PTEN can decrease expression of Caspase-3 to disorder apoptosis of tumor cells, which might explain the molecular mechanisms of PTEN contributions to tumorigenesis and progression of gastric cancer.

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