Identification of SHMT2 as a Potential Prognostic Biomarker and Correlating with Immune Infiltrates in Lung Adenocarcinoma.

Zhiping Lin,Xiaodi Li,Lianxiang Luo,Hui Luo,Liao Cui,Zhipeng Xu,Xiaoling Li,Mingyue Li,Yushi Zheng

doi:10.1155/2021/6647122

Abstract

It has attracted growing attention that the role of serine hydroxy methyl transferase 2 (SHMT2) in various types of cancers. However, the prognostic role of SHMT2 in lung adenocarcinoma (LUAD) and its relationship with immune cell infiltration is not clear. In this study, the information of mRNA expression and clinic data in LUAD were, respectively, downloaded from the GEO and TCGA database. We conducted a biological analysis to select the signature gene SHMT2. Online databases including Oncomine, GEPIA, TISIDB, TIMER, and HPA were applied to analyze the characterization of SHMT2 expression, prognosis, and the correlation with immune infiltration in LUAD. The mRNA expression and protein expression of SHMT2 in LUAD tissues were higher than in normal tissue. A Kaplan-Meier analysis showed that patients with lower expression level of SHMT2 had a better overall survival rate. Multivariate analysis and the Cox proportional hazard regression model revealed that SHMT2 expression was an independent prognostic factor in patients with LUAD. Meanwhile, the gene SHMT2 was highly associated with tumor-infiltrating lymphocytes in LUAD. These results suggest that the SHMT2 gene is a promising candidate as a potential prognostic biomarker and highly associated with different types of immune cell infiltration in LUAD.

Highlights

Lung cancer is the most common cancer and the main reason of cancer-related death, leading to a rising public concern worldwide
0.0 0.0 0.2 0.4 0.6 0.8 1.0 1 – specificity (b) including 624 upregulated and 1244 downregulated genes; 2570 different expression genes (DEGs) screened from the GSE21933 data set, including 1193 upregulated and 1377 downregulated genes; and 7220 DEGs selected from the GSE31210 data set, including 4107 upregulated and 3013 downregulated genes
The P value of the abovementioned cells is all less than 0.001. These results suggested that the serine hydroxy methyl transferase 2 (SHMT2) and its associated genes were important for immune cell infiltration in the lung adenocarcinoma (LUAD) microenvironment and possibly have a more significant effect on the prognosis of LUAD

Summary

Introduction

Lung cancer is the most common cancer and the main reason of cancer-related death, leading to a rising public concern worldwide. Lung cancer is divided into nonsmall cell lung cancer (NSCLC) and small cell lung cancer (SCLC). NSCLC accounts for approximately 85% of all lung cancers [1], which contain two main types: lung squamous cell carcinoma (LUSC) and lung adenocarcinoma (LUAD). LUAD is the most common histological subtype of NSCLC diagnosed, followed by LUSC. As the most common histological subtype, LUAD frequently occurs in females and nonsmoking people, with no obvious clinical symptoms in the early stage, but shared some common symptoms with other respiratory diseases, resulting in difficulty in identification of lung cancer. LUAD has an average 5-year survival rate of less than 20% [2] due to its metastasis at early stages. There is an urgent need to identify new diagnostic and prognostic biomarkers for LUAD to increase the efficacy of early diagnosis

Results

Discussion

Conclusion