TIMP—2基因转染对高转移性人巨细胞肺癌细胞系生物学行为的影响

探讨金属蛋白酶组织抑制因子ＴＩＭＰ－２对肿瘤恶性表型的逆转作用及其在肿瘤基因治疗上的意义。方法利用基因重组技术构建了含全长ＴＩＭＰ－２ｃＤＮＡ的真核表达载体，用脂质体法转染高转移性人肺癌细胞（ＰＧ），检测转染后ＰＧ细胞的金属蛋白酶（ＭＭＰｓ）活性、体外侵袭、裸鼠体内成瘤性及转移能力等多项生物学行为的变化。并以ＴＩＭＰ－２基因转染前后ＰＧ细胞的裸鼠皮下移植瘤为研究对象，利用免疫组织化学和原位杂交方法，研究在整体环境下ＭＭＰ－２、ＭＭＰ－９和ＴＩＭＰ－１、ＴＩＭＰ－２的ｍＲＮＡ及蛋白表达情况。结果转染细胞较母系细胞ＴＩＭＰ－２ｍＲＮＡ表达增强，ＭＭＰ－２、ＭＭＰ－９的产生及活性无明显变化，体外增殖能力增强，但体外侵袭和软琼脂集落形成能力以及裸鼠体内成瘤性及自发转移能力下降。此外，ＭＭＰ－２、ＭＭＰ－９和ＴＩＭＰ－１、ＴＩＭＰ－２在ＰＧ细胞之裸鼠皮下移植瘤的间质细胞及肿瘤细胞均有表达，阳性的肿瘤细胞主要位于肿瘤和间质交界处。结论特异性上调ＴＩＭＰ－２基因的表达可在一定程度上逆转ＰＧ细胞的恶性表型。

Effects of TIMP 2 gene transfection on biological behaviors of a metastatic human lung carcinoma cell line

Objectives To explore the suppressive effects of tissue inhibitor of metalloproteinase 2 (TIMP 2) on malignant phenotype of human carcinoma cells and to evaluate its potential application in cancer gene therapy. Methods A mammalian expression vector containing TIMP 2 cDNA was constructed and transfected into a metastatic human lung carcinoma cell line PG. In vitro and in vivo tests such as Northern blotting, immunohistochemistry as well as x enografting in nude mice experiment were used to analyse expression levels of TIMPs and MMPs, in vitro and in vivo behaviors of the tumor cells before and after the gene transfection. Results After transfection, the TIMP 2 mRNA expression was upregulated significantly. Changes in some malignant phenotypes of the transfectants were seen. For instance, the abilities of in vitro invasion through Matrigel, colony formation on soft agar, tumorigenecity as well as spontaneous metastasis in nude mice were remarkably decreased. Immunohistochemical staining and in situ hybrydization showed that MMP2, MMP9, TIMP 1 and TIMP 2 were expressed by both tumor cells and stromal cells, with stronger staining at the site of tumor invasion. Conclusion Up regulation of TIMP 2 in tumor cells could suppress their expression of malignant phenotype and could be used for cancer therapy.