雷帕霉素激活M2巨噬细胞自噬影响大肠癌放射敏感性的研究  

Rapamycin affects radiosensitivity of colorectal cancer by activating the autophagy of M2 macrophage

作　　者：邵乐宁 朱宝松 杨晓东[1] 曹建平[3] 邢春根[1] Shao Lening;Zhu Baosong;Yang Xiaodong;Cao Jianping;Xing Chungen(Department of Gastrointestinal Surgery,Second Affiliated Hospital of Soochow University,Suzhou 215004,China;Suzhou Hospital of Traditional Chinese Medicine,Suzhou 215007,China;School of Radiation Medicine and Protection,State Key Laboratory of Radiation Medicine and Protection,Soochow University,Suzhou 215123,China)

机构地区：[1]苏州大学附属第二医院胃肠外科,苏州215004 [2]苏州市中医医院,苏州215007 [3]苏州大学放射医学与防护学院放射医学与辐射防护国家重点实验室,苏州215123

出　　处：《中华放射医学与防护杂志》2022年第9期657-663,共7页Chinese Journal of Radiological Medicine and Protection

基　　金：省部共建放射医学与辐射防护国家重点实验室开放课题(GZK1202010,GZK1202021)。

摘　　要：目的探讨雷帕霉素(RAP)激活M2巨噬细胞(type-Ⅱmacrophage)自噬对大肠癌移植瘤放射敏感性的影响。方法经佛波酯(PMA)单独及联合人重组白介素4(IL-4)诱导人单核白血病细胞THP-1分化为M0和M2型巨噬细胞。使用RAP激活M2自噬,设置巴弗洛霉素(bafilomycin A1)下调M2已被激活的自噬作为对照。将大肠癌LoVo细胞接种于BALB/c-nu/nu裸鼠,待形成直径10 mm瘤体后,利用随机数表法,将18只裸鼠分为M2自噬未激活组、激活组和激活后下调组,LoVo细胞单独成瘤为阴性对照组,每组6只。对荷瘤鼠行2次8 Gy X射线局部照射,分析各组间移植瘤放射敏感性的变化。结果M2巨噬细胞标志物Arg-1、CCL-22的相对表达量显著高于M0巨噬细胞(t=78.77、60.02,P<0.05)。M2自噬未激活组瘤体质量、体积和微血管密度(MVD)[(1.93±0.05)g、(2.14±0.06)cm^(3)、36.37±1.04]较阴性对照组[(1.35±0.05)g、(1.77±0.02)cm^(3)、25.69±1.34]显著提高(t=20.07、14.56、10.92,P<0.05);激活M2自噬后,瘤体重量、体积和微血管密度均显著下降[(0.89±0.03)g、(1.24±0.01)cm^(3)、13.60±1.52](t=44.37、40.32、21.43,P<0.05)。利用巴弗洛霉素下调M2自噬后,瘤体质量、体积和微血管密度有所回升[(1.02±0.07)g、(1.37±0.02)cm^(3)、21.06±1.41](t=4.67、13.79、6.23,P<0.05)。与阴性对照组相比,自噬未激活的M2能够抑制Livin和Survivin在瘤体组织中的表达(t=2.64、7.90,P<0.05);RAP激活M2自噬后,可进一步下调上述蛋白的表达(t=5.43、9.39,P<0.05)。利用巴弗洛霉素下调M2自噬后,Livin、Survivin表达量均有所回升(t=2.80、3.17,P<0.05)。结论利用RAP激活M2自噬,可抑制M2促进肿瘤微血管形成的能力,从而抑制移植瘤生长;同时,通过下调大肠癌移植瘤中抗凋亡基因Livin与Survivin的表达,诱导大肠癌移植瘤放疗后凋亡的发生,提高大肠癌的放射敏感性。Objective To investigate the effects of rapamycin on the autophagy activation of M2 macrophages and the radiosensitivity in colorectal cancer xenograft.Methods THP-1 cells were induced into Type-Ⅱmacrophages with PMA and/or IL-4.Rapamycin and Bafilomycin A1 were uesd to activate and suppress autophagy of M2 macrophage,respectively.Colorectal cancer LoVo cells were inoculated on BALB/c-nu/nu nude mice.After the xenograft tumor size approached to 10 mm in diameter,the nude mice were divided into the following groups randomly:M2 macrophage autophagy inactive group and active group,autophagy downregulation of the activated group,and nontreatment control group.The tumors in mice were irradiated with 8 Gy X-rays in two fractions,and the radiosensitivity of colorectal cancer xenograft in each group was analyzed.Results The expression levels of M2 macrophage markers Arg-1 and CCL-22 were significantly higher than those in M0 macrophage.The tumor weight,volume[(1.93±0.05)g,(2.14±0.06)cm^(3)]and micro-vessel density(36.37±1.04)in M2 autophagy inactive group were higher than those in control group[(1.35±0.05)g,(1.77±0.02)cm^(3),25.69±1.34](t=20.07,14.56,10.92,P<0.05).After activation of M2 autophagy,the tumor weight,volume and micro-vessel density were significantly decreased to(0.89±0.03)g,(1.24±0.01)cm^(3),and 13.60±1.52(t=44.37,40.32,21.43,P<0.05).After down-regulation of M2 autophagy with bafilomycin A1,the tumor weight,volume and micro-vessel density were increased to(1.02±0.07)g,(1.37±0.02)cm^(3),and 21.06±1.41(t=4.67,13.79,6.23,P<0.05).Autophagy inaction suppressed the expression of Livin and Survivin in tumor(t=2.64,7.90,P<0.05),and the activation of M2 autophagy further down-regulated the expression of Livin,Survivin(t=5.43,9.39,P<0.05).The expression levels of Livin and Survivin were increased after the treatment with bafilomycin A1(t=2.80,3.17,P<0.05).Conclusions M2 macrophagy promoted the growth of colorectal cancer xenograft by inducing the formation of micro-vessels in the tumor,which is one of t

关 键 词：雷帕霉素 M2巨噬细胞 自噬 大肠癌 放射敏感性 

分 类 号：R96[医药卫生—药理学]