Differential Expression of Nicotine Acetylcholine Receptors Associates with Human Breast Cancer and Mediates Antitumor Activity of αO-Conotoxin GeXIVA.

Zhihua Sun,Shuai Dong,Yiqiao Liu,Dongting Zhangsun,Sulan Luo,Manqi Zhangsun,Jiang Qian

doi:10.3390/md18010061

Abstract

Nicotinic acetylcholine receptors (nAChRs) are membrane receptors and play a major role in tumorigenesis and cancer progression. Here, we have investigated the differential expression of nAChR subunits in human breast cancer cell lines and breast epithelial cell lines at mRNA and protein levels and the effects of the αO-conotoxin GeXIVA, antagonist of α9α10 nAChR, on human breast cancer cells. Reverse transcription polymerase chain reaction (PCR) demonstrated that all nAChR subunits, except α6, were expressed in the 20 tested cell lines. Real time quantitative PCR (QRT-PCR) suggested that the mRNA of α5, α7, α9 and β4 nAChR subunits were overexpressed in all the breast cancer cell lines compared with the normal epithelial cell line HS578BST. α9 nAChR was highly expressed in almost all the breast cancer cell lines in comparison to normal cells. The different expression is prominent (p < 0.001) as determined by flow cytometry and Western blotting, except for MDA-MB-453 and HCC1395 cell lines. αO-conotoxin GeXIVA that targeted α9α10 nAChR were able to significantly inhibit breast cancer cell proliferation in vitro and merits further investigation as potential agents for targeted therapy.

Highlights

Cancer is one of the three principal diseases which lead to human mortality and was responsible for 9.6 million deaths worldwide in 2018 [1]
Previous studies demonstrated that Nicotinic acetylcholine receptors (nAChRs) as ligand-gated ion channels were regulated by binding with acetylcholine (ACh) or nicotinic agonists, such as nicotine and nicotine-containing products [9]
The expression of nAChR subunits has been demonstrated in many non-neuronal cells, including human breast epithelial cells and human breast cancer cells [19,33,34]

Summary

Introduction

Cancer is one of the three principal diseases which lead to human mortality and was responsible for 9.6 million deaths worldwide in 2018 [1]. Nearly 1 in 6 deaths is due to cancer (WHO, 2018) [2]. Breast cancer is the second most common carcinoma in the world following lung cancer and the highest incidence of cancer in women [1]. In China, Chinese cancer registry annual report in 2015 reported that the incidence of breast cancer is still the first vital type of women cancer with an upward trend [3]. It has been proved that nAChRs are expressed in neuronal systems and in numerous non-neuronal tissues and cells, suggesting that nAChRs may have important roles in other biological processes in addition to synaptic transmission. Further studies showed that nAChRs are related to the development of small-cell

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Conclusion