[Study on inhibitory effect of aqueous extract of Taxus chinensis var. mairei on growth of A549 lung cancer xenografts in nude mice and its mechanism].

OBJECTIVE

To study the effect of aqueous extract of Taxus chinensis var. mairei (AETC) on the growth of A549 lung cancer xenografts in nude mice and its mechanism.

METHOD

The A549 lung cancer xenograft model was established, and then randomly divided into the control group, and low, middle and high dose AETC experiment groups. After 24 hours, they were orally administered with normal saline and drugs of the same volume for seven weeks. The length and width of the xenografts were measured every three days, and the xenograft growth curve was drawn. The nude mice were sacrificed after the administration for seven weeks, and their xenografts were collected to cultivate the anti-tumor rate. Real-time PCR and Western-blot were adopted to detect mRNA and protein levels.

RESULT

All of AETC experiment groups showed a significant anti-tumor effect (P < 0.05). Compared with the control group, each experimental group showed notable reduction in EGFR and Survivin mRNA in xenograft tissues (P < 0.05), with no significant change in VEGF mRNA level. The analysis on gray value ratio showed that EGFR mRNA were down-regulated (P < 0.05) in xenograft tissues in all experimental groups, but with no statistical significance in difference, and Survivin and p-EGFR were significantly down-regulated.

CONCLUSION

AETC has not significant effect on angiogenesis, but may have the inhibitory effect on xenograft growth by inhibiting Survivin protein and EGFR phosphorylation.