肾上腺髓质素对786-0肾细胞癌裸鼠移植肿瘤生长及肿瘤血管生成中的作用

Effects of adrenomedullin on growth and angiogenesis of transplanted 786-0 renal cell carcinoma in nude mice

目的 观察肾上腺髓质素（ADM）在786-0肾癌裸鼠移植肿瘤生长及血管生成方面的作用.方法 建立裸鼠人786-0肾癌移植瘤模型,实验分为对照组、ADM诱导组、ADM特异性受体抑制剂ADM22-52干预组.记录成瘤率,通过测量皮下移植瘤体积记录肿瘤生长,苏木素-伊红（HE）染色观察病理形态,免疫组织化学（IHC）染色法检测血管内皮细胞生长因子（VEGF-A）的表达,Western blot法检测ADM受体和VEGF-A蛋白的表达水平.结果 HE染色结果显示移植瘤呈典型的肾透明细胞癌生长特征,其中在ADM22-52干预组中有较多的坏死区域;与对照组比较,ADM诱导组肿瘤体积更大,16d后肿瘤体积为（2 123.50±349.61） mm3,且各组差异有统计学意义（P＜0.05）;免疫组织化学染色结果显示对照组、ADM诱导组、ADM22-52干预组中VEGF-A染色分数分别为4.0、7.5和0.0分,差异均有统计学意义（P＜0.05）;Western blot结果显示ADM受体（ADMR）在对照组、ADM组、ADM22-52组中表达量分别为0.22±0.03、0.28±0.03、0.06±0.01;VEGF-A蛋白在对照组、ADM组、ADM22-52组中表达量分别为0.35±0.11、0.51 ±0.04、0.09±0.01：可见ADM22-52组可显著下调ADMR和VEGF-A蛋白水平的表达,差异均有统计学意义（P＜0.05）.结论 ADM有可能通过激活其自身受体促进786-0肾癌移植肿瘤的生长,并可能参与肾肿瘤血管生成的调节.

Objective To observe the effects of adrenomedullin （ADM） on the growth and angiogenesis of transplanted 786-0 renal cell carcinoma in nude mice.Methods The mouse model of renal cancer was made by transplanting human 786-0 renal tumor cells into the nude mice subcutaneously.The subjects were divided into three groups：control group,ADM group,ADM22-52 group.Tumor formation rate was recorded and the size of tumors was measured.The pathological changes were assessed by hematoxylin and eosin （HE） staining,the expression of vascular endothelial growth factor （VEGF-A） was detected by immunohistochemistry assay in tissues,and the expression of ADM receptor and VEGF-A by Western blotting.Results HE staining showed that transplanted tumors were characterized by clear renal cell carcinoma infiltrating adenocarcinoma,and there were more necrotic areas in the tumor issues in ADM22-52 group.The size of tumors in ADM group was （2 123.50 ± 349.61）mm3 after 16 days,larger than control group and ADM22-52 group （P 〈 0.05）.Immunohistochemistry showed that the expression levels of VEGF-A in control group,ADM group and ADM22-52 group were 4.0,7.5,0.0,respectively （P 〈 0.05）.Western blotting showed that ADM receptor （ADMR） expression levels in control group,ADM group and ADM22-52 group were 0.22 ± O.03,0.28 ± 0.03,and 0.06 ± 0.01 respectively,and VEGF-A expression levels in control group,ADM group and ADM22-52 group were 0.35 ± 0.11,0.51 ± 0.04 and 0.09 ± 0.01 respectively.The expression of ADMR and VEGF-A in ADM22-52 group was significantly down-regulated （P 〈 0.05）.Conclusion ADM may promote the growth of transplanted 786-0 renal cell carcinoma in nude mice by activating the autoreceptors and also may participate the angiogenesis of renal cell carcinoma.