| Chemotherapy is an important treatment in tumor medical therapy. Many curative effects come from the general therapy including chemotherapy. Cell proliferation and carcinogenesis depend on the interaction of host and environment factors. Proliferous and carcinous cells . are multiclonal. The difference between their genotypes and phenotypes accounts for the failure of single chemotherapeutic strategies clinically. It is importunate to develop new anticancer drug and find the proper chemotherapeutic strategies. Although the curative effect of the sensitive tumors has been developed with high-dose chemotherapy, drug resistance and toxicity are considered to be the major impediment to successful cancer chemotherapy. So it is the primary method to increase the general effect by resuming or enhancing the sensitivity of chemotherapeutic drug. It has been demonstrated that the tumors with well differentiation have lower drug sensitivitythan those with poor differentiation. One of the reasons is that those infantile cells have active metabolism and are subject to be attacked. Will the chemotherapeutic effect be improved by treating chemotherapy after increasing the metabolic level? Based on this consideration, we investigated the effect of insulin on chemotherapeutic drug sensitivity from the aspects of cell metabolism, cycle and apoptosis in human esophageal cancer cell line NEC and human liver cancer cell line BEL-7402.Materials and Methods:(1)materials: human esophageal cancer cell line NEC (induced by nitrosamine on human embryo esophageal epithelium);human liver cancer cell line BEL-7402; Insulin; 5-fluorouracil (5HFU);adriamycin (ADM);(2)Cell activity and cell metabolism were assessed by MTT assay. (3)Cell cycle and cell apoptosis were examined by PI fluorescence flow cytometry (FCM). (4) genomic DNA purification was made by phenol/ chloroform assay. DNA ladder was checked by DNA agarose gel electronphores. (5)Morphological changes of apoptosis were observed with transmission electron microscope. (6)All experimental data were analyzed with one-way ANOVA, chi-square and linear correlation and processed by SPSS 10. 0. There was a statistical significance when P<0. 05.Results:(1) 5-FU and ADM 50% concentration are 50.00ug/ml, 6.25 u g/ml respectively, measured by MTT assay . The analysis showedthat inhibitory rate had a linear correlation with chemotherapeutic drug concentration ( 5~FU:r=-0. 893, ADM:r= -0. 707, P<0. 05) .(2) In the test of finding the best inducement time of insulin, the inhibitory rates of 24h, 12h, 8h, 4h, oh before chemotherapy and 4h, 8h, 12h, 24h after chemotherapy were 48. 86%, 48.81%, 74.81%, 73.70%, 59.86%, 48.81%, 41.48%, 48.66%, 48.14% respectively. The inhibitory rate of 5-FU and insulin control groups were 46. 88% and 1. 68% respectively. The 8h and 4h before chemotherapy groups had significant differences compared with 5-FU control group in the three tests (P<0.01). ADM-BEL7402 group had the same result that the inhibitory rates of the 8h and 4h before chemotherapy groups were the highest. In the test of finding the best revulsive concentration of insulin, the inhibitory rates of 0.20mu/ml, 0.60mu/ml, 1.50mu/ml, 5. 00mu/ml, 15.00mu/ml, 45.00mu/ml, 135.00mu/ml, 405. OOmu/ml concentration groups were 48. 49%, 50. 95%, 56. 18%, 65.29%, 66.09%, 67.09%, 66.65%, 66.92% respectively. Concentration groups of 1.50 mu/ml, 5.00 mu/ml, 15.00 mu/ml, 45.00mu/ml, 135.00mu/ml, 405.00mu/ml had significant differences compared with 5-FU and insulin control in the three tests(P<0.01). ADM-BEL7402 groups drew the similar conclusion.(3)The percents of S phase of Insulin 4h, 8h, 12h, 24h, 48h were 60.30%, 58.50%, 56.30%, 47.00%, 46.00% respectively. Compared with control group x 2 = 2551.789 , P=0.000. The7percents of apoptosis of above time groups were 0. 00%, 0. 40%, 5. 10%, 10. 10%, 10. 50% respectively. Compared with the control group, P=0. 000. The percents of S phase of 0. 067mu/ml, 0. 67 mu/ml, 6. 70mu/ml, 67. OOmu/ml, 670. OOmu/ml were 43. 10%,... |
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