【摘要】

摘要 目的：探讨EGCG衍生物Y6联合柔红霉素（Daunorubicin，DNR）对HepG2细胞裸鼠移植瘤生长及血管生成的影响。
方法：建立人肝癌HepG2细胞移植瘤模型，随机分为空白组、EGCG组、Y6-M组、DNR组、DNR+Y6-H组、DNR+Y6-M组、DNR+Y6-L组和DNR+EGCG组，DNR每4天腹腔注射给药，EGCG和Y6每天灌胃给药。观察各组裸鼠肿瘤生长状况，称取瘤体质量并计算抑瘤率；HE染色观察肿瘤组织形态结构改变，用TUNEL法观察肿瘤组织细胞凋亡状况，通过检测CD34表达标记血管，计数测定组织血管密度（MVD），RT-PCR及蛋白免疫印迹法分别检测瘤组织中HIF-1α和VEGF的mRNA及蛋白的表达。
结果：Y6单独或联合DNR对移植瘤生长有抑制作用，并随着Y6联用剂量的增加，抑瘤率显著增加，Y6高剂量时可达（61.1±2.17）%，瘤组织间隙增加、坏死程度加重、凋亡细胞数量明显增多。金正均法计算q值，Y6-M联合DNR给药，q值均大于1.15，药物联用表现为协同效应。Y6单独或联合DNR给药显著抑制瘤体内血管生成，且显著强于EGCG（MVD，p<0.01或p<0.05；显著下调HIF-1α和VEGF等血管生成相关基因的表达)。
结论：Y6可能通过下调HIF-1a和VEGF的表达抑制肿瘤的生长及肿瘤血管的生成并提高人肝癌细胞对DNR的敏感性，使二者联用具有明显的协同作用。

【Abstract】

Abstract Objective: To investigate the effects of epigallocatechin gallate (EGCG) ethyl derivative, Y6 combined with daunorubicin (DNR) on the growth and angiogenesis of HepG2 transplanted tumor tissue.
Methods: The subcutaneously transplanted tumor model of human HepG2 cells in nude mice was estabished. Mice bearing HepG2 hepatoma cells were randomly assigned into 8 groups: Control, EGCG, Y6-M, DNR, DNR+Y6-H, DNR+Y6-M, DNR+Y6-L and DNR+EGCG group. DNR administered intraperitoneally every 4 days, besides, EGCG and Y6 administered orally daily. Nude mice were administered intraperitoneally until day 21. The tumor growth of nude mice in each group was observed.The tumor tissues were weighed and the tumor inhibition rate was calculated. The morphological changes of tumor were observed by hematoxylin-eosin (HE) staining and the apoptosis of tumor cells was detected by a terminal deoxynucletidyl transferase-mediated dUTP neck end labeling (TUNEL) method. The microvessel density (MVD) was markled by CD34. The mRNA and protein expression of HIF-1α and VEGF in tumor tissue were detected by RT-PCR and Western blot, respectively.
Results:Y6 or combined with DNR could significantly inhibit the growth of xenograft tumor. With the increase of Y6 combined dose, the tumor inhibition rate increased significantly and the inhibition rate of Y6 at high dose was (61.1±2.17)%, the tumor tissue space increased, the degree of necrosis increased, and the number of apoptotic cells increased significantly. The combined treatments with DNR+Y6-M resulted in q values exceeding 1.2 and showed an obvious synergistic effect of the drugs. The inhibitory effect of Y6 or combined with DNR on tumor tissue angiogenesis is significantly stronger than that of EGCG (MVD, p<0.01 or p<0.05); Y6 or combined with DNR significantly downregulated the expression of HIF-1α and VEGF, genes associated with tumor angiogenesis, in a dose-dependent manner.
Conclusion  : Y6 may inhibit tumor growth and tumor angiogenesis and increase their sensitivity to DNR by down-regulating the expression of HIF-1a and VEGF and when they combined, Y6 combined with DNR shows a synergistic effect on tumor growth inhibition.