Elevated limb-bud and heart development (LBH) expression indicates poor prognosis and promotes gastric cancer cell proliferation and invasion via upregulating Integrin/FAK/Akt pathway

Ruoxi Yu,Zhi Li,Huicong Song,Mingming Deng,Xiaofang Che,Xiujuan Qu,Ling Xu,Xuejun Hu,Chuang Zhang,Yunpeng Liu,Ye Zhang,Liping Sun

doi:10.7717/peerj.6885

Abstract

The limb-bud and heart development (LBH) gene is a highly conserved, tissue-specific transcription cofactor in vertebrates that regulates multiple key genes in embryonic development. The role of LBH in various cancer types is still controversial, and its specific role and molecular mechanism in the oncogenesis of gastric cancer (GC) remains largely unexplored. In the present study, the prognostic significance and clinicopathological characteristics of LBH in GC was determined. The LBH mRNA expression was first investigated in four independent public datasets (TCGA-STAD, GSE15459, GSE29272, and GSE62254) and then validated with our samples at the protein level. LBH was overexpressed at both the mRNA and protein levels in cancer compared with normal tissues. High LBH expression was correlated with advanced T, N, and M stages. Kaplan–Meier analysis and log-rank test indicated that higher LBH expression was statistically correlated with shorter overall survival (OS) in the public datasets and our study samples. Univariate and multivariate Cox regression analysis showed that LBH was an independent prognostic biomarker for survival in TCGA-STAD, GSE15459, GSE62254 cohorts, and our GC patients. In vitro experiments showed that knockdown of LBH can significantly inhibit the proliferation and invasion of HGC-27 cells, while overexpression of LBH can significantly enhance the proliferation and invasion of BGC-823 cells. Gene Set Enrichment Analysis (GSEA), Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomics (KEGG) indicated that high LBH expression is associated with the PI3K-Akt pathway, focal adhesion, and extracellular matrix (ECM)-receptor interaction. Western blot analysis showed that knockdown of LBH significantly inhibited the expression of integrin α5, integrin β1, p-FAK, and p-Akt. Therefore, results from the present study indicate that LBH is a potential independent prognostic biomarker and promotes proliferation and invasion of GC cells by activating the integrin/FAK/Akt pathway.

Highlights

Gastric cancer (GC) is the most common and lethal type of malignancy worldwide (Katona & Rustgi, 2017)
The limb-bud and heart development (LBH) mRNA expression levels were predicted in GC and adjacent tissues using the online datasets TCGA-STAD and GSE29272
The samples were divided into LBH high expression group and LBH low expression group based on LBH median expression level and the overall survival (OS) was compared between groups

Summary

Introduction

Gastric cancer (GC) is the most common and lethal type of malignancy worldwide (Katona & Rustgi, 2017). Rieger et al first discovered the role of LBH in cancer in 2010 (Rieger et al, 2010). They observed that LBH acts as a target gene for the Wnt pathway to inhibit mammary epithelial differentiation and promote Wnt-induced tumorigenesis (Lindley et al, 2015). LBH has received attention as a new tumor-associated gene, and its role in nasopharyngeal carcinoma (Liu et al, 2015), hepatocellular carcinoma (Chen et al, 2018), prostate cancer (Liu et al, 2018), and lung adenocarcinoma (Deng et al, 2018) has been studied. The expression and biological functions of LBH in GC remain unclear

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Results

Conclusion