The Expression And Significance Of H2-calponin In Gastric Carcinoma

【Background】Gastric carcinoma is one of the most common cancers in our country. Calponin is a family of actin-associated proteins first found in smooth muscle cells. Three calponin isoforms (h1-, h2-, and acidic calponins) are encoded by three homologous genes. h1-calponin is specifically expressed in differentiated smooth muscle cells and has been extensively studied for its role in the regulation of smooth muscle contractility. h2-calponin is found in both smooth muscle and non-muscle cells such as human epidermal keratinocytes. The acidic calponin is found in nervous tissues and implicates in neuronal regeneration and growth. h2-calponin mRNA has been also detected in endothelial cells and fibroblasts . The generegulation and function of h2-calponin are largely unknown.some data show : Calponin binds actin and tropomyosin and is proposed to be an analog of striated muscle troponin and, therefore, may regulate the actin-myosin II-based cytoskeleton function.【Objective】: To identify the expression and distribution of H2-calponin in gastric carcinoma tissues, adjacent tumor tissues(chronic gastritis) and normal gastric mucosa tissues, and to study the relationship of H2-calponin to the biological behavior of gastric carcinoma..【Methods】:1. The H2-calponin expression was examined by immunohistochemistry SP method in 70 gastric carcinoma tissues, 30 adjacent tumor tissues (chronic gastritis) and 30 normal gastric mucosa tissues.2. The H2-calponin expression was examined by western-blot in gastric carcinoma tissue protein and normal gastric mucosa tissue protein 3. The H2-calponin expression was examined by western-blot in GES,GC7901,MKN-28,MKN45,GC9811,9811-P,AGS,SGC7901/VCR cell systems.【Results】:1. The positive rates of H2-calponin in gastric carcinoma tissues, adjacent tumor tissues (chronic gastritis) and normal gastric mucosa tissues were 56.7%, 66.7% and 58.6% respectively. The difference was not statistically significant among gastric carcinoma tissues, adjacent tumor tissues (chronic gastritis) and normal gastric mucosa tissues (P >0.05). It was showed that the expression of H2-calponin protein was positively correlated with the depth of tumor infiltration, lymph node metastasis (P<0.05), but not related to the degree of histological differentiation and the age, sex of patients. 2. H2-calponin protein is highly expressed in GC9811 cell and 9811-P cell systems. There are some relations between H2-calponin and gastric carcinoma metastasis. 3. H2-calponin protein is highly expressed in SGC7901/VCR cell systems. Maybe there are some correlations between H2-calponin and gastric carcinoma multidrug resistance.【Conclusion】: The expression of H2-calponin protein was positively correlated with the depth of tumor infiltration, lymph node metastasis, and the expressions of H2-calponin are correlated with metastasis of gastric carcinoma . there are also some correlations between H2-calponin and gastric carcinoma multidrug resistance.The mechanisms that H2-calponin are involved in the metastasis of gastric carcinoma and MDR are unknown. We need continue to work for the study, hoping to give some clues on the development, progression and treatment of gastric carcinoma.