Cell-type specificity of β-actin expression and its clinicopathological correlation in gastric adenocarcinoma

AIM: To investigate cell type specific distribution of β-actin expression in gastric adenocarcinoma and its correlation with clinicopathological parameters. METHODS: β-actin is a housekeeping gene, frequently used as loading control, but, differentially expresses in cancer. In gastric cancer, an overall increased expression of β-actin has been reported using tissue disruptive techniques. At present, no histological data is available to indicate its cell type-specific expression and distribution pattern. In the present study, we analyzed β-actin expression and distribution in paired normal and tumor tissue samples of gastric adenocarcinoma patients using immunohistochemistry (IHC), a tissue non-disruptive technique as well as tissue disruptive techniques like reverse transcriptase-polymerase chain reaction (RT-PCR) and western blotting. Correlation of β-actin level with clinicopathological parameters was done using univariate analysis. RESULTS: The results of this study showed significant overexpression, at both mRNA and protein level in tumor tissues as confirmed by RT-PCR (1.47 ± 0.13 vs 2.36 ± 0.16; P 0.05). CONCLUSION: In gastric cancer, β-actin showed an overall higher expression predominantly contributed by inflammatory or tumor infiltrating immune cells of the tissue microenvironment and correlates with tumor grade.