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AIM: To analyze the apoptosis promoting effect of breviscapine on NSCLC cells and the growth of transplanted tumor and investigate the mechanism. METHODS: The apoptosis, Caspase-3 activity, Bax and Bcl-2 expression of A549 cells treated with 25, 50 and 100 μmol/L breviscapine were detected. The subcutaneous transplanted tumor model was constructed with A549 cells. The mice were intraperitoneally injected with 10 mg/kg and 20 mg/kg breviscapine every day. The size and weight of the tumor were observed every week. On the 21st day, the mice were killed and the tumor was obtained. The expression of Bax and Bcl-2 was detected by Western blot. Bax/Bcl-2 ratio was analyzed. Caspase-3 expression was detected by immunohistochemistry and apoptosis in the tumor was detected by TUNEL staining. RESULTS: Breviscapine increased the apoptosis rate of A549 cells. The results of enzyme labeling showed that Caspase-3 activity increased significantly after breviscapine treatment compared with the control group. Western blot showed that breviscapine could significantly inhibit the expression of anti-apoptosis protein Bcl-2, increase the expression of pro-apoptosis protein Bax, and increase the ratio of Bax/Bcl-2. In vivo, on the 14th and 21st day, the tumor size of the treatment group was significantly smaller than that of the control group, while the weight of nude mice was not significantly reduced. Western blot showed that breviscapine could upregulate the expression of Bax and down regulate the expression of Bcl-2 in the transplanted tumor, while the expression of Caspase-3 was significantly increased. TUNEL staining showed that the proportion of apoptosis increased significantly compared with the control after breviscapine treatment. CONCLUSION: Breviscapine can induce the apoptosis of A549 cells in vitro and in vivo. The mechanism may be that breviscapine upregulates Bax expression and downregulates Bcl-2 expression, increases Bax/Bcl-2 ratio, activates Caspase-3, resulting in A549 cell apoptosis.
ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the enhanced effect of gemcitabine by emodin and the possible mechanisms of the enhancement.</p><p><b>METHOD</b>Based on the model of SW1990 cell xenograft on athymic mouse, the mice were randomized to four groups with intraperitoneal (IP) injections of different drugs: group N (injecting 0.9% sodium chloride), group E (emodin, 40 mg x kg(-1)), group G (gemcitabine, 125 mg x kg(-1)), and group E + G (emodin 40 mg x kg(-1) and gemcitabine 80 mg x kg(-1) in combination). The tumor volume, tumor weight and body weight of mice were measured during the drug therapy. The mice were sacrificed one week after last injection of drug. Tunel assay were used used to detect the apoptosis of tumor cells. And immunohistochemistry (IHC) and Western blot (WB) were used to detect the variance of the apoptosis relative protein expression of Bax, Bcl-2, and Cytochrome C .</p><p><b>RESULT</b>One week after the last administration, the mean tumor volume and tumor weight in group E + G were significantly decreased compared to the other groups. Tunel assay showed group E + G presented apparently more apoptosis than the other groups. Immunohistochemistry (IHC) and Western blot (WB) analysis showed the expression of Cytochrome C in cytoplasmin and Bax in group E + G was apparently upregulated while the expression of Bcl-2 was apparently downregulated compared to the other groups. As a result, Bcl-2/Bax ratio was significantly decreased in group E + G.</p><p><b>CONCLUSION</b>Emodin can significantly improve the antitumor effect of gemcitabine on transplanted tumor of SW1990 cell line through apparently enhancing the tumor cell apoptosis by gemcitabine. Downregulation of Bcl-2/Bax ratio and promoting release of Cytochrome C from mitochondria is possibly one of the mechanisms of the augmented apoptosis.</p>