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Objective: To observe the antitumor effect of triptolide in the human pancreatic cancer tumor-bearing nude mice, and to explore its molecular mechanism. Methods: The healthy BALB/ c nude mice were selected and transplanted with the human pancreatic cancer SW1990 cells into the skin of the right hind limb to establish the tumor-bearing model of nude mice. The successful modeling nude mice were divided into model group, gemcitabine group and triptolide group, 10 in each group; another 10 healthy nude mice were selected as control group. The tumor tissue of SW1990 pancreatic cancer tumor-bearing nude mice were weighed and the inhibitory rate of tumor was calculated. The expressions of apoptosis-related proteins Bax and bcl-2 in the pancreas tissue of the nude mice in each group were detected by rmmunohistochemistry. The expression levels of Bax, bcl-2, Caspase-9 and Caspase-3 in the pancreas tissue of the nude mice in each group were detected by Western blotting method. Results: Compared with gemcitabine group, the inhibitory rate of tumor of SW1990 pancreatic cancer in triptolide group was significantly increased (P < 0. 05). The HE staining results showed that compared with model group, the proliferation of pancreatic cancer tumor cells in triptolide group was inhibited. The immunohistochemistry results showed that the expression level of Bcl-2 in the pancreas tissue and the Bcl-2 /Bax ratio of the nude mice in tripptolide group were lower than those in model group (P < 0 . 05). The Western blotting results showed that compared with model group, the expression levels of Bax, Caspase-9 and Caspase-3 in the pancreas tissue of the nude mice in triptolide group were significantly increased (P < 0 . 05), while the expression level of Bcl-2 was significantly decreased (P < 0 . 05). Conclusion: Triptolide can inhibit the growth of tumor tissue in the nude mice; its mechanism may be related to inhibiting the activation of Bcl-2 in pancreatic tumor tissue, promoting the expression of Bax, reducing the ratio of Bcl-2 /Bax, promoting the activation of Caspase-9 and Caspase-3, and inducing the apoptosis of pancreatic cancer transplanted tumor cells.
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@#Objective: To investigate the relationship between drug resistance and expression of ABC-binding cassette subfamily B member 1 (ABCB1) as well as its promoter methylation in pancreatic cancer. Methods: Fifteen pairs of pancreatic cancerous tissues and corresponding para-cancerous tissues, which were pathologically verified in Fujian Cancer Hospital from August 2015 to August 2018, were collected for this study; in addition, 3 cases of normal pancreatic tissues and pancreatic cancer cell line SW1990 were also collected. Gemcitabine (GEM)-resistant human pancreatic cancer cell line SW1990/GZ was induced by intermittent concentration gradient multiplication method. The expression level ofABCB1 in SW1990 cells, SW1990/GZ cells, pancreatic cancer tissues and apara-cancerous tissues was detected by qPCR. Methylation of ABCB1 promoter region in SW1990 cells, SW1990/GZ cells and pancreatic cancerous tissues was determined by MSP-PCR. Results: Compared with SW1990 cells, the morphology of SW1990/GZ cells showed more vacuoles, more mitotic images, clumpy growth and increased drug resistance (P<0.05). ABCB1 expression in pancreatic cancer tissues was significantly higher than that in para-cancerous tissues (P<0.01). The expression of ABCB1 in SW1990 and SW1990/GZ cells was significantly higher than that in normal pancreatic tissues (P<0.05 or P<0.01), and the expression of ABCB1 in SW1990/GZ cells was higher than that in SW1990 cells (P<0.05). ABCB1 promoters in SW1990, SW1990/GZ cells and normal pancreatic tissues were hypomethylated. Rate of methylation in pancreatic can cerous tissues and normalpancreatic tissues was 6.7%(1/15) and 0.00%(0/3) respectively,and the difference was statistically insignificant (all P>0.05). Conclusion: Increased ABCB1 expression in pancreatic cancer tissues and cells is associated with drug resistance, but its gene expression does not depend on promoter methylation regulation.
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Aim To study the inhibitory effects and its mechanisms of oridonin on human pancreas adenocarcinoma SW1990 cells.Methods Cell growth inhibition mediated by oridonin on SW1990cells was measured by MTT assay.The morphological changes were observed by Hoechst33258 fluorochrome staining and electron microscope.Cell cycle and apoptosis rate were analyzed by flow cytometry. The molecular mechanisms involved in the effects of oridonin on SW1990 cells were studied by RT-PCR.Results The growth of humen pancreas adenocarcinoma SW1990 cells was significantly inhibited by oridonin.Apoptosis morphological changes about chromatic agglutination and nuclear condensation were detected by Hoechst 33258 fluorochrome staining and electron microscope in oridonin treated SW1990 cells."Sub-G_1" phase peak and G_2/M growth arrest werer found with flow cytometry.The upregulating mRNA expression of p21 and downregulating mRNA expression of survivin were detected by RT-PCR.Conclusion The inhibitory effect of oridonin on human pancreas adenocarcinoma SW1990 cells through induced apoptosis and G_2/M growth arrest and the mechanisms may be through surviving-p21 co-regluation pathway.