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 a...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 113cases of gastric cancers were studied for the expression of PTEN and Caspase-3 andmicrovessel 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％ vs89.4％; 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-3to disorder apoptosis of tumor cells, which might explain the molecular mechanisms of PTEN contributions to tumorigenesis and progression of gastric cancer.展开更多
AIM: To investigate the loss of heterozygosity (LOH) and mutation of tumor suppressor gene PTEN in gastric cancer and precancerous lesions. METHODS: Thirty cases of normal gastric mucosa, advanced and early stage gast...AIM: To investigate the loss of heterozygosity (LOH) and mutation of tumor suppressor gene PTEN in gastric cancer and precancerous lesions. METHODS: Thirty cases of normal gastric mucosa, advanced and early stage gastric cancer, intestinal metaplasia, atrophic gastritis, and atypical hyperplasia were analyzed for PTEN LOH and mutations within the entire coding region of PTEN gene by PCR-SSCP denaturing PAGE gel electrophoresis, and PTEN mutation was detected by PCR-SSCP sequencing followed by silver staining. RESULTS: LOH rate found in respectively atrophic gastritis was 10% (3/30), intestinal metaplasia 10% (3/30), atypical hyperplasia 13.3% (4/30), early stage gastric cancer 20% (6/30), and advanced stage gastric cancer 33.3% (9/30), None of the precancerous lesions and early stage gastric cancer showed PTEN mutations, but 10% (3/30) of the advanced stage gastric cancers, which were all positive for LOH, showed PTEN mutation. CONCLUSION: LOH of PTEN gene appears in precancerous lesions, and PTEN mutations are restricted to advanced gastric cancer, LOH and mutation of PTEN gene are closely related to the infiltration and metastasis of gastric cancer.展开更多
文摘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 113cases of gastric cancers were studied for the expression of PTEN and Caspase-3 andmicrovessel 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％ vs89.4％; 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-3to disorder apoptosis of tumor cells, which might explain the molecular mechanisms of PTEN contributions to tumorigenesis and progression of gastric cancer.
基金Supported by the National Natural Science Foundation of China,No. 30070845
文摘AIM: To investigate the loss of heterozygosity (LOH) and mutation of tumor suppressor gene PTEN in gastric cancer and precancerous lesions. METHODS: Thirty cases of normal gastric mucosa, advanced and early stage gastric cancer, intestinal metaplasia, atrophic gastritis, and atypical hyperplasia were analyzed for PTEN LOH and mutations within the entire coding region of PTEN gene by PCR-SSCP denaturing PAGE gel electrophoresis, and PTEN mutation was detected by PCR-SSCP sequencing followed by silver staining. RESULTS: LOH rate found in respectively atrophic gastritis was 10% (3/30), intestinal metaplasia 10% (3/30), atypical hyperplasia 13.3% (4/30), early stage gastric cancer 20% (6/30), and advanced stage gastric cancer 33.3% (9/30), None of the precancerous lesions and early stage gastric cancer showed PTEN mutations, but 10% (3/30) of the advanced stage gastric cancers, which were all positive for LOH, showed PTEN mutation. CONCLUSION: LOH of PTEN gene appears in precancerous lesions, and PTEN mutations are restricted to advanced gastric cancer, LOH and mutation of PTEN gene are closely related to the infiltration and metastasis of gastric cancer.
