METTL7B (methyltransferase-like 7B) identification as a novel biomarker for lung adenocarcinoma

Jawad Ali; Wenwen Liu; Wenzhe Duan; Chang Liu; Jing Song; Sameen Ali; Encheng Li; Qi Wang

doi:10.21037/atm-20-4574

METTL7B (methyltransferase-like 7B) identification as a novel biomarker for lung adenocarcinoma

Ann Transl Med. 2020 Sep;8(18):1130. doi: 10.21037/atm-20-4574.

Authors

Jawad Ali¹, Wenwen Liu¹, Wenzhe Duan¹, Chang Liu¹, Jing Song¹, Sameen Ali², Encheng Li¹, Qi Wang¹

Affiliations

¹ Department of Respiratory Medicine, The Second Hospital, Dalian Medical University, Dalian, China.
² Dalian Medical University, Dalian, China.

Abstract

Background: Lung adenocarcinoma (LUAD) is still one of the major causes of cancer-related mortality across the globe. Therefore, there is a dire need to identify early specific and sensitive biomarkers or drug targets of LUAD for developing improved diagnosis and clinical management. We aimed to investigate the role of methyltransferase-like 7B (METTL7B) on LUAD tumor development and progression in this study.

Methods: METTL7B's expression was confirmed in two independent clinical cohort samples, including LUAD tissues microarray (TMA) via immunohistochemistry (IHC) and serum samples via enzyme-linked immunosorbent assay (ELISA). The correlation between METTL7B expression with clinicopathological features and overall survival rate in LUAD patients was then further analyzed. Meanwhile, the messenger ribonucleic acid (mRNA) and protein levels of METTL7B were verified in cell lines and in vitro experiments, including cell proliferation assay, and migration. Invasion assays were conducted to explore the effects of METTL7B on LUAD by silencing the protein expression.

Results: METTL7B was remarkably overexpressed in clinical LUAD tumor tissues and serum compared to the normal control group and in LUAD cell lines. The expression level of METTL7B was significantly correlated with tumor size, advanced tumor node and metastases (TNM) stages, and lymph node metastasis. The Kaplan-Meier survival curves proved that high METTL7B expression was significantly associated with a reduced survival rate in LUAD patients (P<0.05), and univariate analysis showed that high METTL7B expression was significantly associated with poor overall survival [hazard ratio (HR) =2.220, 95% confidence interval (CI): 1.211-4.086; P=0.010]. In vitro assays showed that METTL7B overexpression augmented cell proliferation, migration, and the invasion in LUAD.

Conclusions: METTL7B was overexpressed in LUAD and significantly associated with the poor progression, showing that METTL7B may serve as a potential novel biomarker for the diagnosis and prognosis of LUAD. Moreover, METTL7B plays a role in promoting tumor proliferation, migration, and invasion in LUAD.

Keywords: Biomarkers; lung adenocarcinoma (LUAD); metastasis; methyltransferase-like 7B (METTL7B).