褪黑素体内外对小鼠前胃癌细胞的增殖抑制与凋亡诱导作用

Effect of melatonin on proliferation inhibition and apoptosis induction in the murine foregastric carcinoma cell in vivo and in vitro

目的探讨褪黑素(MLT)在体内外对小鼠前胃癌(MFC)细胞的增殖抑制与凋亡诱导作用。方法体内实验:建立荷胃癌小鼠模型,随机分为5组:A.正常对照组;B.荷瘤空白对照组:每日注射生理盐水100 mg/kg;C.小剂量褪黑素组:荷瘤成功后(接种第6天起)每日腹腔注射MLT 25 mg/kg;D.中剂量MLT组:每日腹腔注射MLT 50 mg/kg;E.大剂量MLT组:每日腹腔注射MLT 100 mg/kg。褪黑素连续注射1周后完整剥离小鼠瘤体并测量其重量体积。体外实验:建立不同浓度褪黑素对胃癌细胞干预模型,运用荧光双标染色,流式细胞术、CCK-8等方法检测褪黑素对小鼠前胃癌细胞增殖抑制和凋亡诱导作用。结果与荷瘤空白对照组相比,褪黑素体内明显下调瘤体的重量体积;与空白对照组相比,褪黑素体外明显抑制胃癌细胞增殖活性,细胞凋亡率增加,并使细胞周期阻滞在G2/M期,并呈剂量依赖性。结论褪黑素在体内外均能抑制小鼠前胃癌细胞的增殖活性,并呈时间-剂量依赖性,该作用与促细胞凋亡和细胞周期G2/M期阻滞有关。

Objective To investigate the effect of melatonin （MLT） on proliferation inhibition and apoptosis induction in the murine foregastric carcinoma （MFC） cell in vivo and in vitro. Methods We performed an in vivo study by inoculating MFC cell line in mice. The mice models were successfully established as follows： Group A. Normal control mice; Group B, Tumor-bearing control mice with daily intraperitoneal injection of 100 mg/kg saline water; Group C, Tumor-bearing mice with low dosage of 25 mg/kg MLT via intraperitoneal injection; Group D, Tumor-bearing mice with medium dosage of 50 mg/kg MLT; Group E, Tumor-bearing mice with high dosage of 100 mg/kg MLT. One week after MLT injection, tumor samples were collected and weighted. In vitro experiment, we performed a cell model by MFC cells treatment with different concentrations of melatonin, and then the effect of MLT on MFC cell proliferation and cycle change was detected by using double immunofluorescence staining, flow cytometry, CCK-8 and other methods. Results Compared with the tumor-bearing control mice, the tumor weights and volumes of the melatonin treated tumor-bearing mice group were significantly reduced. Compared with the blank control, melatonin had inhibitory effect on gastric cancer cell proliferation in vitro, increased cell apoptosis and arrested of the cell cycle at the G2/M phase, which exhibited a dose dependent. Conclusion Melatonin has a potent anti-gastric cancer proliferation effect in vivo and in vitro, and the mechanism is associated with concentration and time-dependent effect of melatonin-induced cell apoptosis. This apoptosis was also related to the arrest of the cell cycle at the G2/M phase in vitro.