Canstatin high level expression system and its biology effects on lung cancer / 中国癌症杂志

ABSTRACT

Purpose:To study the biological effects of high secreted canstatin on human umbilical vein endothelial cells (HUVEC) and tumor model. Methods:Hypoxic responsive elements (HREs) were inserted in the upper stream of canstatin cDNA of a recombinant vector we constructed in a former research. The new recombinant vector named pCMV-3HRE-CEAS-Cans was transferred into A549 cells by cationic liposome; canstatin mRNA expression in the transformed cells under oxic and anoxic condition was detected by Taqman PCR. Then we designed a co-cultured assay HUVECs were co-cultured with recombinant vector transformed A549 cells with Transwell plates, and the proliferation and apoptosis of co-cultured HUVECs were evaluated with 3H-thymidine incorporation method, TUNEL method respectively. Finally the vector was introduced into tumor tissues of lung cancer-bearing nude mice, and the biological activity in the tumor tissues was tested by micro-vessel count (MVC). A vector of canstatin we constructed before was used as controls in above experiments.Results:The pCMV-3HRE-CEAS-Cans vector was successfully constructed and transferred into A549 cells. canstatin mRNA was detected both in the recombinant vector transformed A549 cells and the pCMV-CEAS-Cans transformed A549 cells, moreover the expression of canstatin in the new vector transformed A549 was significantly higher than that of the controls under hypoxic condition. ~(3)H-TdR intake rate of HUVECs was decreased markedly, and a large amount of them underwent apoptosis when they were co-cultured with recombinant vector transformed A549 cells. Significant differences of ~(3)H-TdR intake rate and apoptotic rate of co-cultured HUVEC were found between pCMV-3HRE-CEAS-Cans group and any of the controls (P