Upregulated Expression of SHMT2 Predicts Poor Survival of Lung Adenocarcinoma

Backgrounds: Serine hydroxy methyltransferase 2 (SHMT2) exerts an essential function in the cellular serine/glycine biosynthesis and one-carbon metabolism. Accumulative evidence revealed that SHMT2 was involved in cancer initiation and development in several types of carcinomas such as glioma, intrahepatic cholangiocarcinoma and colorectal cancer. However, expression and role of SHMT2 in lung adenocarcinoma (LUAD) had not been fully investigated. Methods: Transcriptional information of SHMT2 was retrieved from TCGA database. mRNA and protein expression of SHMT2 were analyzed in LUAD tissues alongside adjacent normal lung tissues using quantitative RT-PCR and immunohistochemical staining. The prognostic significance of SHMT2 in LUAD was assessed through both univariate and multivariate statistical analyses. Results: SHMT2 was higher in LUAD tissues than that in adjacent lung tissues on transcriptional level, mRNA level, and protein level. Elevated SHMT2 protein levels were associated with increased tumor size, positive lymph node metastasis, and more advanced TNM stages. LUAD patients with high SHMT2 level had worse prognosis. Conclusions: Our research indicated that elevated SHMT2 expression is strongly linked to adverse clinical characteristics and poor prognosis in LUAD patients. Consequently, SHMT2 may represent a novel prognosis marker and a promising therapeutic target regarding the treatment of LUAD.