17-DMAG抑制津白Ⅱ小鼠乳腺癌肝脾转移的实验研究及其相关机制

The Inhibitory Effect of 17-DMAG on Liver and Spleen Metastasis of TA2 Mouse Mammary Cancer and Its Mechanisms

目的：动态观察HSP90抑制剂17-dimethylamjnoethylamino-17-demethoxygeldanamycin hydrochloride对津白Ⅱ小鼠高转移性乳腺癌生长及肝脾转移的抑制作用，并初步探讨其相关机制。方法：TA2小鼠40只，随机分为实验组和对照组，20只/组，自小鼠鼠鼷部接种TA2小鼠高转移性乳腺癌细胞，1×10^5/只。接种肿瘤后第4天于小鼠腹腔给予17-DMAG，1mg/（只·次），2次，周，于接种后17天和24天实验组和对照组各处死10只小鼠，收集小鼠移植瘤、肝和脾组织，留取部分新鲜组织进行Real-time PCR，检测实验组和对照组肿瘤组织中MMP-7、MMP-9 mRNA的表达差别。剩余组织10％福尔马林固定后HE染色及基质金属蛋白酶-7的免疫组织化学染色。结果：接种肿瘤后第17天实验组的肿瘤体积明显低于对照组，差异具有统计学意义（P〈0．05）；实验组16只小鼠中肝转移5例，脾脏转移13例，对照组13只小鼠中肝转移13例，脾脏转移12例；实验组小鼠肝转移例数较对照组明显下降（P〈0．01），而脾转移例数差别无统计学意义（P〉0．05）。HE染色下观察实验组肿瘤出现明显的坏死。实验组中MMP-7蛋白和MMP-9 mRNA的表达较对照组明显减弱（分别为3．049±2．726和21．933±14．304；1．034±0.784和2．318±1．294），差异均具有统计学意义（P〈0．05）。结论：17-DMAG可明显抑制TA2小鼠乳腺癌的生长，尤其是在肿瘤生长的早期，并可能通过降低MMP-7、MMP-9的表达来抑制TA2小鼠乳腺癌肝脾的转移。

Objective： To study the inhibitory effect of 17-DMAG on the growth of TA2 mouse mammary cancer and metastasis to the liver and spleen and to investigate the corresponding mechanisms. Methods： Forty TA2 mice were randomly divided into the experimental group and the control group, with 20 in each group. The mammary cancer cells with high metastasis potential were transplanted to mouse groin （1×10^5/ each mouse）. Each mouse was given 17-DMAG （lmg） by intraperitoneal injection from the fourth day after tumor transplantation twice a week. In each group, 10 TA2 mice were sacrificed on the 17th and 24th day after tumor transplantation, respectively. We collected the tissues of transplanted tumor, liver and spleen. Some fresh tissues were freozen for real-time PCR. We detected the expression of MMP-7 and MMP-9 mRNA in the experimental and control groups. Immunohistochemistry staining was used to detect the expression of MMP7. Results： The gross tumor volume of the experimental group was lower than that of the control group on the 17th day after tumor transplantation, with a significant difference （P〈0.05）. Of the 16 mice in the experimental group, 5 had liver metastasis and 13 had spleen metastasis. Of the 13 mice in the control group, 13 had liver metastasis and 12 mice had spleen metastasis. The tumors in the experimental group showed obvious necrosis. The expression of MMP-7 proteins and MMP-9 mRNA in the experimental group was lower than that in the control group （3.049±2.726 and 21.933±14.304; 1.034±0.784 and 2.3182±1.294, respectively）, with a statistical significance （P〈0.05）. Conclusion： 17-DMAG can obviously inhibit the growth of TA2 mouse mammary cancer, especially in the early period after tumor transplantation. 17-DMAG can possibly inhibit the metastasis of TA2 mouse mammary cancer by decreasing the expression of MMP-7 and MMP-9.