外源p53基因和抗血管生成小肽F56联合对小鼠乳腺癌移植瘤生长和转移的抑制作用

目的:观察腺病毒介导的野生型p53基因联合抗血管生成小肽 F56对乳腺癌移植瘤及其肺转移灶的抑制作用.方法:将人乳腺癌BICR-H1细胞接种于裸鼠或NOD/SCID小鼠乳垫内.成瘤后,裸鼠随机分成Adp53 F56组、 Adp53组、F56组和空白对照组,NOD/SCID小鼠则随机分成Adp53 F56组、Adp53组、F56组、Adlacz组和空白对照组,分别采用腺病毒p53、F56或二者联合治疗,以小肽溶剂作对照,NOD/SCID小鼠还加用腺病毒空载体(Adlacz)作对照.观察裸鼠移植肿瘤体积、组织病理学改变,用免疫组织化学方法检测肿瘤p53、血管内皮生长因子(vascular endothelial growth factor, VEGF)的表达及微血管密度(microrascular density, MVD);观察NOD/SCID小鼠移植瘤的肺转移情况.结果:p53基因、F56及二者联合治疗均能明显抑制裸鼠移植瘤生长,但以联合治疗组最显著,Adp53 F56组、Adp53组、F56组和空白对照组肿瘤最终的相对生长体积分别为2.47、4.37、4.69和12.49 ;免疫组织化学检测发现,Adp53 F56组和Adp53组肿瘤内p53表达增高,P53阳性率分别增高了9.4%、6.3%,但与空白对照组比较,差异无统计学意义(P=0.693);Adp53 F56组、Adp53组、F56组VEGF表达下降, VEGF阳性率分别下降21.9%、9.4%和3.1%,但与空白对照组比较,差异亦无统计学意义(P=0.284);Adp53 F56组、Adp53组、F56组MVD分别为14.50±2.54、16.28±3.44和18.06±7.66,与空白对照组(24.93±6.53)比较,差异有统计学意义(P=0.000), 且Adp53 F56组、Adp53组、F56组瘤内出现坏死,并以Adp53 F56组最为明显.NOD/SCID小鼠Adp53 F56组、Adp53组、F56组肺转移灶平均数目分别为1.143±0.378, 2.750±0.886, 3.375±0.518,较Adlacz组(5.000±0.816)和空白对照组(5.670±0.817 )都显著减少(P=0.000),尤以Adp53 F56组最少.结论:p53基因联合抗肿瘤血管生成小肽F56可显著抑制肿瘤的生长和转移.p53基因影响肿瘤生长与转移的因素之一可能与p53对VEGF的抑制作用有一定关系.

Inhibitory effect of Adp53 and F56 on growth and metastasis of transplantation of the breast tumor in mice

OBJECTIVE: To investigate the effects of Adp53 and F56 on the growth and lung metastasis of breast cancer. METHODS: The BICR-H1 cells were inoculated into the mammary fatty pad of BALB/C nude mice and NOD/SCID mice to establish breast cancer model. Then the nude mice with xenograft tumor were randomized into group Adp53+F56, Adp53, F56 and control. The NOD/SCID mice with xenograft tumor were randomized into group Adp53+F56, Adp53, F56, Adlacz and control. They were treated for 3 weeks according to the plan, diversity of the volume and histopathology of xenograft tumor of nude mice was observed and the expressions of p53 and VEGF gene, and microvessel density (MVD) were detected by immunohistochemistry. Lung metastasis of breast cancer in NOD/SCID mice was observed. RESULTS: (1) Intratumoral injections of Adp53, F56, and their combination resulted in an inhibition on the growth of xenograft tumor of BICR-H1 cells. The ultimate relative growth volumes of groups Adp53+F56, Adp53, F56 and control were 2.47,4.37,4.69 and 12.49 respectively. (2) After treatment, P53 positive rate of group Adp53+F56, Adp53 increased 9.4%, 6.3% than before respectively, but compared with control group, the difference is not significant (P=0.693); VEGF protein of group Adp53+F56, Adp53 and F56 decreased 21.9%, 9.4% and 3.1% than before respectively, but compared with control group, the difference was not significant (P=0.284). Necrosis and decrease of vessel in the tumor and morphological change of endothelium were observed under light microscope in the groups Adp53+F56, Adp53 and F56. MVD estimated by FVIII-RA staining of group Adp53+F56, Adp53 and F56 were 14.50+/-2.54, 16.28+/-3.44 and 18.06+/-7.66, compared with control group(24.93+/-6.53), the difference is significant (P=0.000). (3) The average number of lung metastasis of NOD/SCID mice in group Adp53+F56, Adp53 and F56 were 1.143+/-0.378, 2.750+/-0.886 and 3.375+/-0.518 respectively, lower than Adlacz group(5.000+/-0.816) and control group (5.670+/-0.817) obviously (P=0.000). CONCLUSION: Adp53 combined with F56 can greatly inhibit growth and metastasis of breast cancer in vivo. The mechanism of anti-tumor effects of Adp53 and F56 may be related to the anti-angiogenesis effect on malignant tumor through inhibiting the expression and activity of VEGF.