Expression, Clinical Significance, and Functional Prediction of MNX1 in Breast Cancer

Tian Tian,Meng Wang,Yuyao Zhu,Wenge Zhu,Tielin Yang,Hongtao Li,Shuai Lin,Cong Dai,Yujiao Deng,Dingli Song,Na Li,Zhen Zhai,Zhi-Jun Dai

doi:10.1016/j.omtn.2018.09.014

Abstract

Motor neuron and pancreas homeobox 1 (MNX1) is a key developmental gene. Previous studies found that it was upregulated in several tumors, but its role in breast cancer (BC) remains unclear. In order to have a better understanding of this gene in BC, we examined the expression of MNX1 in BC tissues and normal breast tissues by qRT-PCR and by analyzing data from The Cancer Genome Atlas (TCGA) database. We also assessed the association of MNX1 expression with BC clinicopathological features and investigated the impact of MNX1 on BC survival. Potential molecular function of MNX1 was predicted through protein-protein interactions and functional enrichment. The results showed that the expression of MNX1 was significantly increased in BC tissues, especially in the HER2-positive subtype, and MNX1 expression was associated with several clinical characteristics, including menopause status, receptor status, subtypes, tumor size, lymph node metastasis, and race. In addition, patients with higher MNX1 expression had poorer survival. Enrichment analysis suggested that MNX1 is probably involved in biological processes and pathways related to nuclear division, cell cycle, and p53 signaling. In conclusion, our study suggests that MNX1 may act as a tumor promoter in BC. We hope these findings will draw more attention to MNX1 in future cancer studies.

Highlights

Breast cancer (BC) is the most common cancer type and the leading cause of global cancer death among females.[1]
In order to have a better understanding of MNX1in BC, we investigated its expression profile and clinical significance in BC and the impact of its expression on BC survival while exploring the potential molecular function through bioinformatic analysis and experimental method
motor neuron and pancreas homeobox 1 (MNX1) Expression Is Upregulated in BC Tissues We explored the expression profile of MNX1 in BC tissues using The Cancer Genome Atlas (TCGA) dataset

Summary

Introduction

Breast cancer (BC) is the most common cancer type and the leading cause of global cancer death among females.[1]. MNX1, located on human chromosome 7q36.3, belongs to the family of homeobox genes It encodes a nuclear protein named motor neuron and pancreas homeobox 1 (MNX1), known as HLXB9 or HB9, which is a transcription factor.[3] MNX1 is a key developmental gene that is normally expressed in neurons as well as pancreatic and lymphoid cells. It is involved in both motor neuronal differentiation and pancreatic beta cell development.[4,5,6] Defects in this gene result in hereditary sacral agenesis, which is called Currarino syndrome.[7,8] The function of MNX1 in cancer biology has not been clarified. The expression of MNX1 has been reported to be upregulated in several tumors, including prostate cancer, hepatocellular carcinoma (HCC), acute myeloid leukemia (AML), and neuroblastoma.[3,9,10,11] it has been demonstrated to be oncogenic in prostate cancer and insulinoma.[12,13]

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Results

Conclusion