应激对小鼠乳腺癌生长转移的作用及机制  

Effect of stress on growth and metastasis of breast cancer and its mechanism

作　　者：芦婷婷 胡颖芸 张提 秦君芳[1] LU Ting-ting;HU Ying-yun;ZHANG Ti;QIN Jun-fang(Department of Immunology,School of Medicine,Nankai University,Tianjin 300071,China)

机构地区：[1]南开大学医学院免疫学教研室

出　　处：《解放军医学杂志》2019年第6期459-465,共7页Medical Journal of Chinese People's Liberation Army

基　　金：国家自然科学基金(31800661);天津市自然科学基金(16JCQNJC11700);天津市大学生创新训练计划百项工程(201710055336)~~

摘　　要：目的 探讨应激对小鼠乳腺癌生长转移的作用及机制。方法 6~8周龄BALB/c小鼠接种4T1细胞制备乳腺癌移植瘤模型,分为对照组、慢性应激组、Iso[异丙肾上腺素,10mg/(kg.d)]组、慢性应激+DMSO(二甲基亚砜)组和慢性应激+Rapa[雷帕霉素,15mg/(kg.d)]组。记录癌组织体积变化,并于造模第21天处死小鼠,检测瘤内Beclin1、微管相关蛋白1轻链3-Ⅱ(LC3-Ⅱ)和p62表达变化;同时进行肺墨汁染色,计数小鼠肺内转移结节。采用去甲肾上腺素(NE)处理4T1细胞,观察自噬相关分子Beclin1、LC3-Ⅱ、p62mRNA和蛋白表达的变化。结果 与对照组[(1359.7±173.9)mm^3]相比,应激刺激[(2119.7±130.0)mm^3]和Iso注射[(1947.0±102.8)mm^3]可促进乳腺瘤体的生长(P<0.05),同时,肺内转移结节数也呈现同样的变化趋势[慢性应激组(10.3±1.1)个,Iso组(8.8±0.5)个vs.对照组(4.3±0.3)个,P<0.05];慢性应激组瘤内Beclin1、LC3-Ⅱ表达减少,而自噬的抑制性分子标志物p62表达增加(P<0.05);自噬诱导剂Rapa可逆转应激的促瘤效果[(2275.477±187.397)mm^3vs.(1360.097±213.938)mm^3,P<0.05]。与生理盐水组相比,NE处理后4T1细胞内Beclin1表达减少约60%(100%vs.39.8%±2.0%,P<0.05),绿色荧光蛋白(GFP)-LC3的点状聚集也明显减少(P<0.05)。生物信息学分析显示高表达Beclin1的乳腺癌患者生存预后更好,高表达p62者则正相反(P<0.001)。结论 应激通过抑制细胞自噬促进乳腺癌的生长和转移。Objective To investigate the potential mechanisms of chronic stress-induced breast cancer progression.Methods Mouse breast cancer xenograft model was established by injecting 4T1 cells into 6-week-old BALB/c mice,followed by randomized into the control group(no induced stress or drug treatment),chronic stress group,Iso injection group[10 mg/(kg.d),served as positive control],chronic stress+DMSO group(served as control for drug treatment),and chronic stress+Rapa group[15 mg/(kg.d)].The tumor size was monitored up to 21 days.The intratumor expression levels of Beclin1,LC3-Ⅱ,and p62 were detected.The pulmonary metastatic nodules were visualized and counted using lung ink staining.The expression of autophagyrelated molecules in 4T1 cells after NE treatment was also examined in vitro.Results Compared with the control group[(1359.7±173.9)mm^3],chronic stress[(2119.7±130.0)mm^3],and Iso[(1947.0±102.8)mm^3]promoted the growth of breast cancer cells(P<0.05).Consistently,the lung nodules numbers were significantly increased in the chronic stress group(10.3±1.1)and the Iso group(8.8±0.5),compared to control group(4.3±0.3,P<0.05).In addition,compared to the control group,Beclin1 expression from samples of the stress group were decreased while p62 expression increased(P<0.05).Interestingly,the autophagy inducer Rapa reversed the pro-tumorigenic effect of chronic stress[(2275.477±187.397)mm^3 vs.(1360.097±213.938)mm^3,P<0.05].We further confirmed that 4T1 cells treated with NE resulted in 60%decreased of Beclin1 expression in 4T1(100%vs.39.8%±2.0%,P<0.05)the fluorescence intensity of LC3 decreased as well(P<0.05).Bioinformatics analysis showed that breast cancer patients with high expression of Beclin1 had better survival prognosis,while those with high expression of p62 showed worse outcome(P<0.001).Conclusion Stress promotes the growth and metastasis of breast cancer through suppressing cell autophagy.

关 键 词：应激 乳腺癌 自噬 去甲肾上腺素 

分 类 号：R737.9[医药卫生—肿瘤]