孟鲁司特和扎鲁司特,半胱氨酰白三烯受体拮抗剂(LTRAs),引发三阴性乳腺癌MDA-MB-231细胞凋亡并抑制细胞增殖。相比之下,只有扎鲁司特诱导G0/G1细胞周期阻滞。本研究比较了这些药物对调节细胞增殖的蛋白质的作用,凋亡,自噬,使用逆转录定量PCR,内质网(ER)和氧化应激,蛋白质印迹和流式细胞术。增殖标志物的表达,Ki-67和增殖细胞核抗原,这两种药物都减少了。扎鲁克斯特,但不是孟鲁司特,细胞周期蛋白D1和CDK4的表达降低,从而中断从G1到S期的进展。扎鲁司特还增加了细胞周期抑制剂p27的表达。两种药物均降低了抗凋亡蛋白Bcl-2和ERK1/2磷酸化的表达,自噬标记LC3-II和DNA损伤标记的水平升高,包括裂解的PARP-1,磷酸化(p)-ATM和p-组蛋白H2AX。与扎鲁司特处理的细胞相比,孟鲁司特处理的细胞中caspase3/7阳性细胞的数量更多。与扎鲁司特相比,孟鲁司特诱导更高水平的ER应激标志物CHOP。孟鲁司特激活PERK,激活转录因子6(ATF6)和需要肌醇的酶1型(IRE1)途径,而扎鲁司特仅刺激ATF6和IRE1途径。GSK2606414,一种PERK抑制剂,孟鲁司特介导的细胞凋亡减少,但不影响扎鲁司特诱导的细胞死亡。小干扰RNA对CHOP的敲除减少了孟鲁司特和扎鲁司特引发的凋亡。总之,对细胞周期调节蛋白的影响可能有助于扎鲁司特引起的细胞周期停滞。孟鲁司特的更大的凋亡效应可能是由更高水平的激活的caspase酶和三个途径的内质网应激的激活引起的:PERK,ATF6和IRE1。
Montelukast and zafirlukast, cysteinyl leukotriene receptor antagonists (LTRAs), trigger apoptosis and inhibit cell proliferation of triple‑negative breast cancer MDA‑MB‑231 cells. By contrast, only zafirlukast induces G0/G1 cell cycle arrest. The present study compared the effects of these drugs on proteins regulating cell proliferation, apoptosis, autophagy, and endoplasmic reticulum (ER) and oxidative stress using reverse transcription‑quantitative PCR, western blotting and flow cytometry. The expression of proliferating markers, Ki‑67 and proliferating cell nuclear antigen, was decreased by both drugs. Zafirlukast, but not montelukast, decreased the expression of cyclin D1 and CDK4, disrupting progression from G1 to S phase. Zafirlukast also increased the expression of p27, a cell cycle inhibitor. Both drugs decreased the expression of anti‑apoptotic protein Bcl‑2 and ERK1/2 phosphorylation, and increased levels of the autophagy marker LC3‑II and DNA damage markers, including cleaved PARP‑1, phosphorylated (p)‑ATM and p‑histone H2AX. The number of caspase 3/7‑positive cells was greater in montelukast‑treated cells compared with zafirlukast‑treated cells. Montelukast induced higher levels of the ER stress marker CHOP compared with zafirlukast. Montelukast activated PERK, activating transcription factor 6 (ATF6) and inositol‑requiring enzyme type 1 (IRE1) pathways, while zafirlukast only stimulated ATF6 and IRE1 pathways. GSK2606414, a PERK inhibitor, decreased apoptosis mediated by montelukast, but did not affect zafirlukast‑induced cell death. The knockdown of CHOP by small interfering RNA reduced apoptosis triggered by montelukast and zafirlukast. In conclusion, the effects on cell cycle regulator proteins may contribute to cell cycle arrest caused by zafirlukast. The greater apoptotic effects of montelukast may be caused by the higher levels of activated caspase enzymes and the activation of three pathways of ER stress: PERK, ATF6, and IRE1.