Abstract 4816: Overexpression of thymosin β10 gene is not mediated by DNA methylation in non-small cell lung cancer

Proceedings: AACR 102nd Annual Meeting 2011‐‐ Apr 2‐6, 2011; Orlando, FL Lung cancer is the leading cause of cancer-related deaths worldwide and is usually associated with a late diagnosis and a poor prognosis. Thymosin β10 (TMSB10) is monomeric actin sequestering protein to regulate actin cytoskeleton organization. The aberrant TMSB10 expression has been implicated in the pathogenesis of human cancers. However, its role in carcinogenesis is still controversial. To better understand the role of TMSB10 in lung tumorigenesis and its regulatory mechanism, we have examined the methylation status and expression of the TMSB10 gene in non-small cell lung cancers (NSCLCs) using methylation-specific PCR (MSP) and immunohistochemistry (IHC), respectively. MSP analysis showed that TMSB10 promoter was almost unmethylated in tumor tissues and became to be hypomethylated in 7 out of 139 (5.0%) NSCLCs. However, there is no significant association of TB10 demethylation with clinicopathologic features. IHC showed that TMSB10 protein was strongly expressed in the cytoplasm of malignant cells and its overexpression was detected in 15 of 30 (50.0%) the tumor tissues compared to normal tissues. Moreover, TMSB10 overexpression was frequently observed in sqaumous cell carcinomas compared to adenocarcinomas with border line significance (P = 0.072), but its overexpression was not associated with the methylation status of TMSB10 gene. Collectively, these results suggest that TMSB10 overexpression may be a frequent event in the progression of NSCLC, but DNA methylation may not involve in TMSB10 overexpression. However, further studies with a large number of cases are needed to confirm our findings. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4816. doi:10.1158/1538-7445.AM2011-4816