Water-soluble variant of human Lynx1 induces cell cycle arrest and apoptosis in lung cancer cells via modulation of α7 nicotinic acetylcholine receptors
Water-soluble variant of human Lynx1 induces cell cycle arrest and apoptosis in lung cancer cells via modulation of α7 nicotinic acetylcholine receptors
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DOI：
10.1371/journal.pone.0217339
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发表时间：
2019-05-31
期刊：
影响因子：
3.7
通讯作者：
Lyukmanova, Ekaterina
中科院分区：
文献类型：
--
作者：
Bychkov, Maxim;Shenkarev, Zakhar;Lyukmanova, Ekaterina
Lynx 1是第一个在哺乳动物中枢神经系统中发现的三指原毒素。它是一种GPI锚定蛋白，调节脑中的烟碱乙酰胆碱受体（nAChR）。除大脑外，Lynx 1蛋白还存在于肺和肾中。内源性Lynx 1调控尼古丁诱导的肺腺癌A549细胞α 7型nAChRs表达上调及细胞生长在这里，我们分析了Lynx 1在人类上皮细胞中的表达。Lynx 1在mRNA和蛋白水平的表达在正常口腔角质形成细胞，肺，结肠，表皮和乳腺癌细胞中检测到，但在胚胎肾细胞中没有。Lynx 1与α 7-nAChR共定位于肺腺癌A549和结肠癌HT-29细胞的细胞膜中，但不用于乳腺癌MCF-7和表皮样癌A431细胞。不含GPI锚的Lynx 1的重组水溶性变体（wsLynx 1）抑制A549细胞的生长，通过调节α 7-nAChR和激活不同的细胞内信号级联，包括PKC/IP 3，MAP/ERK，p38和JNK途径，导致细胞周期停滞。用ws-Lynx 1处理A549细胞导致促凋亡肿瘤抑制蛋白p53的磷酸化，并且不同激酶参与基因转录、细胞生长、粘附和分化的调节。通过流式细胞术观察到的磷脂酰丝氨酸（一种早期凋亡标志物）的外化证实了ws-Lynx 1处理后A549细胞中的凋亡诱导。我们的数据揭示了ws-Lynx 1调节上皮癌细胞稳态的能力。
Lynx1 is the first three-finger prototoxin found in the mammalian central nervous system. It is a GPI-anchored protein modulating nicotinic acetylcholine receptors (nAChRs) in the brain. Besides the brain, the Lynx1 protein was found in the lung and kidney. Endogenous Lynx1 controls the nicotine-induced up-regulation of the expression of alpha 7 type nAChRs in lung adenocarcinoma A549 cells as well as the cell growth. Here, we analyzed the Lynx1 expression in the set of human epithelial cells. The Lynx1 expression both at the mRNA and protein level was detected in normal oral keratinocytes, and lung, colon, epidermal, and breast cancer cells, but not in embryonic kidney cells. Co-localization of Lynx1 with alpha 7-nAChRs was revealed in a cell membrane for lung adenocarcinoma A549 and colon carcinoma HT-29 cells, but not for breast adenocarcinoma MCF-7 and epidermoid carcinoma A431 cells. The recombinant water-soluble variant of Lynx1 without a GPI-anchor (wsLynx1) inhibited the growth of A549 cells causing cell cycle arrest via modulation of alpha 7-nAChRs and activation of different intracellular signaling cascades, including PKC/IP3, MAP/ERK, p38, and JNK pathways. A549 cells treatment with ws-Lynx1 resulted in phosphorylation of the proapoptotic tumor suppressor protein p53 and different kinases participated in the regulation of gene transcription, cell growth, adhesion, and differentiation. Externalization of phosphatidylserine, an early apoptosis marker, observed by flow cytometry, confirmed the induction of apoptosis in A549 cells upon the ws-Lynx1 treatment. Our data revealed the ability of ws-Lynx1 to regulate homeostasis of epithelial cancer cells.