纳米材料碘油混悬液栓塞后兔VX2肿瘤组织MT1-MMP表达改变的意义

Expression of MT1-MMP and its significance in rabbit VX2 tumor tissues after transarterial embolization with hydroxyapatite nanopartides

目的观察应用羟基磷灰石纳米粒子和超液化碘油混悬液栓塞后，兔VX2肿瘤组织膜型基质金属蛋白酶-1（MT1-MMP）表达变化的意义。方法60只接种VX2肿瘤细胞的荷瘤兔随机分为3组：肿瘤组、超液化碘油组、羟基磷灰石纳米超液化碘油混悬液组。通过胃十二指肠动脉插管分别给予：生理盐水（1ml／只）、超液化碘油（0．3ml／kg）、纳米超液化碘油混悬液（0．3ml／kg）。术后3dCT检查确认插管成功。两周后，应用免疫组织化学三步法（S-P）测定肿瘤组织MT1-MMP的表达定位，以及治疗干预后表达量的改变。RT—PCR检测MT1-MMP mRNA的表达差异，Western blot法分析MT1-MMP蛋白表达变化。结果MT1-MMP在肿瘤细胞膜和肿瘤组织间质都有表达。肿瘤组与碘油组、纳米碘油组的阳性表达相比，差异有统计学意义（P〈0．05），而碘油组和纳米碘油组则无明显差异（P〉0．05）。Western blot法检测各组蛋白量的表达也支持此结果。RT-PCR检测3组mRNA表达值的对比无明显差异（P〉0．05）。结论MT1-MMP主要表达于肿瘤细胞膜和间质。超液化碘油和（或）羟基磷灰石纳米粒子栓塞后，肿瘤组织及间质的MT1-MMP的表达上调，可能是造成栓塞后肿瘤转移复发率高的分子机制之一。

Objective To study location of MT1-MMP and effect of its change in expression on rabbit VX2 tumor tissues after transarterial embolization with hydroxyapatite nanoparticles loaded with lipiodol. Methods Sixty rabbits implanted with tumor tissue of cell line VX2 were divided into three groups （control group, lipiodol group, hydroxyapatite nanoparticles loaded with lipiodol group ）. The transarterial embolization was performed superselectively via gastro- duodenal artery of rabbits, each rabbit in control group was inserted with 1 ml normal saline, that in lipiodol group was inserted with 0.3 lipiodol ml/kg, also 0.3 ml hydroxyapatite nanoparticles loaded with lipiodol per kg for that in the last group. Results of embolization were detected by using CT scanning 3 days after operation. After two weeks, all tumors were took out as specimens to investigate location of MT1-MMP in VX2 tumor tissues, and also to determine the change of its expression in tumor tissues after embolization with different medicines, with three-step immunohistochemical technique（S-P）. MT1-MMP mRNA was measured by RT-PCR to determine whether there were differences in three groups. Western blot technique was performed to determine difference of MT1- MMP protein expression of in three groups. Results Immunohistochemical results exposed that MT1-MMP was expressed on membrane of tumor cells and in extracellular matrix of tumor cells. Comparison of MT1- MMP expression in control group with that in other two groups, showed a significant lower level in control group（ P 〈 0.05 ）. There was no difference in MT1-MMP expression between lipiodol group, hydroxyapatite nanoparticles loaded with lipiodol group （ P 〉 0. 05 ）. Western blot supported this conclusion. RT-PCR detecting MT1-MMP mRNA was found no differences among three groups （P 〉 0.05 ）. Conclusions MT1- MMP was mainly expressed on membrane of tumor cells and in extracellular matrix of tumor cells. There was an increasing tendency on expression of MT1-MMP in tumor tissues and extracellular matrix after transarterial embolization with hydroxyapatite nanoparticles loaded with lipiodol,it might be one of important mechanisms provoking high recurrence rate for hepatocellular carcinoma after treatment embolization.