Effects of Yiqi Chutan Decoction on the growth of cisolatin-resistant cells of lung cancer and apoptosis of UPR-induced cells

Objective: To observe the effects of Yiqi Chutan Decoction(YQCT) on the growth of subcutaneous xenografts with cisolatin-resistant lung cancer and endoplasmic reticulum stress related proteins. Methods: The model of lung cancer subcutaneous xenografts was established in nude mice using cisolatin-resistant lung cancer line A549/DDP. The mice were randomly divided into three groups: control group, low dosage group and high dosage group of YQCT. Xenografs growth curves was drawed and tumor weight ratio and inhibition rate were calculated. The histomorphology changes of tumor tissue were observed by HE staining and electron microscope. The apoptosis rate of cancer cells were detected by flow cytometry, and the expression levels of GRP78/Bip, PDI, PERK, p-PERK, e IF2α, p-e IF2α were measured by using western bloting. Results: Compared with the control group, the high dosage of YQCT could inhibit tumor growth and promote apoptosis of tumor cells significantly(P<0.05, P<0.01). YQCT also could reduce the expression levels of GRP78/Bip, PDI, p-PERK, p-e IF2α(P<0.01), but the expression level of PERK and e IF2α of each group had no statistical significance. Conclusion: There is concentration dependent of YQCT in inhibiting of tumor cell growth in nude mouse by transplanting of cancer cells with cisplatin resistance, and the mechanism is related to the down-regulating the expressions of GRP78/Bip, PDI, p-PERK and p-e IF2α, weakening the expression of unfolded protein response(UPR), and the initiating of endoplasmic reticulum apoptotic pathways.