Hypomethylation of the thymosin β(10) gene is not associated with its overexpression in non-small cell lung cancer.
Lung cancer is the leading cause of cancer-related deaths worldwide and is usually associated with a late diagnosis and a poor prognosis. Thymosin β(10) (TMSB10) is a monomeric actin sequestering protein that regulates 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 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 the TMSB10 promoter was already unmethylated in most tumor tissues and became demethylated in 20 (14.4%) of the 139 NSCLCs. TMSB10 hypomethylation was not significantly correlated with the clinicopathological features. IHC showed that the TMSB10 protein was strongly expressed in the cytoplasm of malignant cells and its overexpression was detected in 50.0% of the tumor tissues compared to normal tissues. TMSB10 overexpression was frequently observed in sqaumous cell carcinomas compared to adenocarcinomas with border line significance (P = 0.072). However, TMSB10 methylation status was not linked to its overexpression. Collectively, these results suggest that TMSB10 hypomethylation may be a frequent event in NSCLCs, but it may not be a common mechanism underlying TMSB10 overexpression. However, further studies with large numbers of patients are needed to confirm our findings.
Department of Anatomy, School of Medicine, Kyungpook National University, Daegu 702-422, Korea.
Su Man
SM
Lee
Yeon Kyung
YK
Na
Hae Sook
HS
Hong
Eun Jeong
EJ
Jang
Ghil Suk
GS
Yoon
Jae Yong
JY
Park
Dong Sun
DS
Kim
D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics / Q000378:metabolism* / Q000401:mortality / Q000473:pathology / Q000503:physiopathology; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic; D019175:DNA Methylation; D018450:Disease Progression; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000401:mortality / Q000473:pathology / Q000503:physiopathology; D008297:Male; D009367:Neoplasm Staging; D011401:Promoter Regions, Genetic / Q000235:genetics; D016019:Survival Analysis; D013947:Thymosin / Q000494:pharmacology*; D015854:Up-Regulation / Q000187:drug effects
D013947:Thymosin; C039302:thymosin beta(10)