腺病毒介导的mda-7／IL-24抑制肝癌VEGF和MMP-9的表达

Adenovirus - mediated MDA - 7/IL - 24 down - regulates the expression of VEGF and MMP -9 in highly metastatic human liver cancer cells in vitro and in vivo

目的 观察mda-7/IL-24基因对高转移性人肝癌细胞HCCLM6中VEGF和MMP-9的作用,从而探讨mda-7/IL-24基因在抑制肿瘤转移方面的作用.方法 构建Ad.Mda-7并转染至HCCLM6;transwell实验检测侵袭能力的变化;通过RT-PCR和Western Blot分别检测转染mda-7/IL-24基因前后VEGF和MMP-9表达mRNA和蛋白的变化;构建HCCLM6高转移型裸鼠模型,采用Ad.Mda-7肿瘤内注射法干预,观察mda-7/IL-24对裸鼠生存状况的影响和肿瘤内VEGF和MMP-9 的变化.结果 复制缺陷型腺病毒能介导外源基因mda-7/IL-24在肝癌细胞中高效表达;mda-7/IL-24能显著下调肝癌细胞中VEGF和MMP-9的表达.Ad.mda-7能延长裸鼠的生存时间,抑制肿瘤的生长,瘤体内VEGF和MMP-9表达明显降低（P〈0.05）.结论 mda-7/IL-24基因能明显抑制肝癌细胞的侵袭力,其机制可能与下调VEGF和MMP-9的表达有关.

Objective To observe the effects of melanoma differentiation - associated gene -7 （mda -7/IL -24） on the expression of VEGF and MMP -9 in HCCLM6 cells in vitro and in vivo and investigate its role in metastasis of tumor. Methods The mda - 7/IL - 24 gene was transfected into HCCLM6 cells with a replication - incompetent adenovirus vector. The ability of invasion was measured by Transwell chamber assay. The mRNA and protein expression of mda - 7/IL - 24, VEGF and MMP - 9 in HCCLM6 cells was detected by RT - PCR and Western blot, separately. Ad. mda - 7 was injected into the tumor - bearing mice, and its effects on the growth of the tumor and the survival rate of the mice were observed. The protein expression of VEGF and MMP - 9 in tumor tissue was examined by immunohistochemistry. Results Both RT - PCR and Western blot revealed that the exogenous mda - 7/IL - 24 gene was expressed in HCCLM6 cells. After transfeetion of mda - 7/IL - 24 gene into HCCLM6 cells, the ability of invasion was decreased. Compared with the blank control group, the expression levels of both VEGF and MMP -9 in mda -7/IL -24 gene transfected were inhibited. After Ad. mda -7 administration, the tumor grew slower and the mice survived longer. Compared with the blank group, the mice treated with Ad. mda - 7 had a longer average survival time （ 61.4 ± 1.67 days, P 〈 0.05 ）, and the average size of tumor treated with Ad. mda - 7 was diminished significantly （ P 〈 0.05 ）. Ad. mda - 7 blocked the expression of VEGF and MMP - 9 in vivo. Conclusion mda - 7/IL - 24 down - regulates the expression of VEGF and MMP - 9 in vitro and in vivo. mda - 7/IL - 24 may have a great contribution to anti - metastatic potential through the down - regulation of VEGF and MMP - 9 expression.