BACKGROUNDLung cancer is one of the most malignant cancers which is hazarding the people's health and life in the world. At present, it is a highlight to exploit antitumor drug from plant at home and abroad. The aim of this study is to observe the effects of polysaccharid (PS-T) on expression of angiogenic-related gene mRNA in human high-metastatic large cell lung cancer cell line L9981, and to explore its possible molecular mechanism.

METHODSL9981 in vitro was cultured, and the growth data were obtained by trypan blue staining. The mRNA transcript expression of β-catenin, E-cadherin, TIMP-1, CD44V6, MMP-2, endostatin, VEGF was detected in L9981 by RT-PCR before and after treating with PS-T. The ability of invasion of L9981 was determined by Boyden chamber method.

RESULTS(1)PS-T had remarkably inhibitive effects on the growth of L9981 in vitro. The inhibitive rate of PS-T on L9981 was concentration-dependent. No significant difference of inhibitive rate was found among the PS-T (1g/L), cisplatin (3mg/L) and PS-T (0.05g/L) + cisplatin (1.5mg/L)(P > 0.05). (2)The mRNA expression level of β-catenin, E-cadherin, TIMP-1, endostatin and MMP-2 was upregulated, while that of VEGF and CD44V6 was downregulated. Out of them the mRNA expression level of TIMP-1 and endostatin was remarkably upregulated, the expression level of CD44V6 was significanyly downregulated. (3)The in vitro invasive abilities of L9981 was significantly decreased in the PS-T, DDP and PS-T+DDP groups compared with that in blank control group.

CONCLUSIONS(1)PT-S could inhibit the growth of human high-metastatic large cell lung cancer cell line L9981 in vitro, the effect is dose-dependent. (2)PS-T can down- or up-regulate the mRNA transcript expression of some angiogenic-related gene mRNA. (3)PS-T has remarkably coordinating effects with cisplatin in the L9981 lung cancer cell line.