Tropomyosin 2 exerts anti-tumor effects in lung adenocarcinoma and is a novel prognostic biomarker

Abstract

Background. Tropomyosin 2 (TPM2), a member of the actin filament binding protein family, plays distinct roles in the progression of different cancer types. Until now, there has been no study reporting TPM2 expression nor its function in lung adenocarcinoma (LUAD). Methods. In the present study, we examined the expression profile of TPM2 by immunohistochemistry (IHC). The clinical significance of TPM2 was assessed by univariate and multivariate analyses. Function of TPM2 in LUAD was evaluated by knockdown and overexpression strategies in three LUAD cell lines, followed by proliferation and invasion assays. Xenografts were conducted in nude mice to further validate the tumor-related role of TPM2. Results. Our results showed that TPM2 was downregulated in LUAD specimens and the low expression of TPM2 was associated with poor outcomes of LUAD patients. Overexpressing TPM2 inhibited cell proliferation and invasion of LUAD cell lines, while silencing TPM2 exerted the opposite effects. The effects of TPM2 in LUAD were further confirmed by xenograft assays. Conclusions. Our results indicated that TPM2 exerted an anti-oncogenic role in LUAD via inhibiting tumor progression, thus providing a novel dire