Wen Jing, Zhao Yuyan, Shen Yang, Guo Lei
Department of Endocrinology, First Affiliated Hospital, China Medical University, Shenyang, Liaoning 110001, P.R. China.
Department of Orthopedic Surgery, First Affiliated Hospital, China Medical University, Shenyang, Liaoning 110001, P.R. China.
Mol Med Rep. 2015 May;11(5):3439-44. doi: 10.3892/mmr.2015.3190. Epub 2015 Jan 13.
Orexins are a class of peptides involved in the regulation of food intake, energy homeostasis, the sleep‑wake cycle and gastrointestinal function. Recent studies have demonstrated that orexin A may influence apoptosis and proliferation in numerous types of cancer cells. However, the effect of orexin A on gastric cancer cells and its mechanisms of action remain elusive. In the present study, BGC‑823 gastric cancer cells were treated with orexin A (10‑10‑10‑6 M) in vitro and the expression levels of orexin receptor 1 (OX1R) protein in cells was then determined. The proliferation, viability and apoptosis of BGC‑823 cells were detected. In addition, BGC‑823 cells were treated with AKT inhibitor PF‑04691502 or OX1R‑specific antagonist SB334867 in combination with orexin A, in order to examine the activation of AKT and caspase‑3. The results showed that orexin A (10‑10‑10‑6 M) stimulated the OX1R protein expression in BGC‑823 cells, which improved the proliferation and viability of the cells as well as protected them from apoptosis. Phosphorylated AKT protein was significantly increased in BGC‑823 cells following treatment with orexin A. Moreover, 10‑8 M orexin A reduced the proapoptotic activity of caspase‑3 (by ≤30%). The OX1R antagonist SB334867 (10‑6 M) and AKT antagonist PF‑04691502 (10‑6 M), when used individually or in combination, abolished the effect of orexin A (10‑8 M) on BGC-823 cells. In conclusion, the results of the present study demonstrated that orexin A inhibited gastric cancer cell apoptosis via OX1R through the AKT signaling pathway.
食欲素是一类参与调节食物摄入、能量平衡、睡眠-觉醒周期和胃肠功能的肽。最近的研究表明，食欲素A可能影响多种类型癌细胞的凋亡和增殖。然而，食欲素A对胃癌细胞的作用及其作用机制仍不清楚。在本研究中，体外使用食欲素A（10⁻¹⁰⁻¹⁰⁻⁶ M）处理BGC-823胃癌细胞，然后测定细胞中食欲素受体1（OX1R）蛋白的表达水平。检测BGC-823细胞的增殖、活力和凋亡情况。此外，用AKT抑制剂PF-04691502或OX1R特异性拮抗剂SB334867与食欲素A联合处理BGC-823细胞，以检测AKT和半胱天冬酶-3的激活情况。结果显示，食欲素A（10⁻¹⁰⁻¹⁰⁻⁶ M）刺激BGC-823细胞中OX1R蛋白表达，提高细胞的增殖和活力，并保护细胞免于凋亡。用食欲素A处理后，BGC-823细胞中磷酸化AKT蛋白显著增加。此外，10⁻⁸ M食欲素A降低了半胱天冬酶-3的促凋亡活性（降低≤30%）。OX1R拮抗剂SB334867（10⁻⁶ M）和AKT拮抗剂PF-04691502（10⁻⁶ M）单独或联合使用时，均可消除食欲素A（10⁻⁸ M）对BGC-823细胞的作用。总之，本研究结果表明，食欲素A通过AKT信号通路经OX1R抑制胃癌细胞凋亡。
