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ACTA2

actin, alpha 2, smooth muscle, aorta;ACTA2;actin, alpha 2, smooth muscle, aorta

actin, aortic smooth muscle|alpha-cardiac actin|cell growth-inhibiting gene 46 protein

10q23.3

protein-coding

In this study, we analyzed the microvessel density (MVD) for CD105+ and alpha-SMA+ vessels and the VEGF immunoexpression in 38 gastric carcinomas. CD105+ MVD had superior values at the advancing edge compared with the intratumoral area, no matter of the analyzed clinico-pathological parameters, the difference being significant only in intestinal type, moderate differentiated carcinomas as well as in T2-T3 carcinomas, without lymph node metastases (p<0.05). Intratumoral expression of CD105+ MVD indicated significant differences related to histological type (p=0.006), depth of invasion (p=0.027) and lymph node metastases (p=0.009), but without statistical association in case of the advancing edge or metastases. The assesses of alpha-SMA+ MVD indicated no differences between intratumoral and advancing edge areas, no matter of the analyzed parameters, excepting intestinal type carcinomas, which presented significant high values (p=0.003) at the advancing edge. VEGF score revealed significant differences related to histological type (p=0.020), differentiation degree of the intestinal type carcinomas (p=0.036) and depth of invasion (p=0.049). In case of metastases, the levels of VEGF expression were higher in the primary tumor, without statistically significant differences (p>0.05). It were significant differences of intratumoral VEGF expression depending on CD105+ MVD values (p=0.019), but not with alpha-SMA+ MVD (p>0.05). Angiogenesis evaluated through the VEGF and MVD (CD105+ and alpha-SMA+) expression is correlated with the progression and metastasis of gastric cancer and could be considered a prognostic marker of these tumors.

PURPOSE: metastatic relapse of primary lung cancer leads to therapeutic resistance and unfavorable clinical prognosis; therefore, identification of key molecules associated with metastatic conversion has significant clinical implications. We previously identified a link between early brain metastasis of lung adenocarcinoma and amplification of the alpha-smooth muscle actin (ACTA2) gene. The aim of present study was to investigate the prognostic and functional significance of ACTA2 expression in cancer cells for the metastatic potential of lung adenocarcinomas. EXPERIMENTAL DESIGN: ACTA2 expression was analyzed in tumor cells from 263 patients with primary lung adenocarcinomas by immunohistochemistry, and was correlated with clinicopathologic parameters. The expression of ACTA2 in human lung adenocarcinoma cells was modulated with short hairpin RNAs (shRNA) and siRNAs specifically targeting ACTA2. RESULTS: The patients with lung adenocarcinomas with high ACTA2 expression in tumor cells showed significantly enhanced distant metastasis and unfavorable prognosis. ACTA2 downregulation remarkably impaired in vitro migration, invasion, clonogenicity, and transendothelial penetration of lung adenocarcinoma cells without affecting proliferation. Consistent with the in vitro results, depletion of ACTA2 in human lung adenocarcinoma PC14PE6 cells significantly reduced their metastatic potential without altering their tumorigenic potential. expression of c-MET and FAK in lung adenocarcinoma cells was also reduced by ACTA2-targeting siRNAs and shRNAs, and was accompanied by a loss of mesenchymal characteristics. CONCLUSIONS: These findings indicate that ACTA2 regulates c-MET and FAK expression in lung adenocarcinoma cells, which positively and selectively influence metastatic potential. Therefore, ACTA2 could be a promising prognostic biomarker and/or therapeutic target for metastatic lung adenocarcinoma.