Anticancer Effect Of Myxobacteria Metabolite On H₂₂ Tumor Bearing Mice And Its Correlation With Bcl-2, P53and Apoptosis

In this paper, a total of100strains preserved by the Key Lab of Microbial Diversity Researchand Application of Hebei Province were used to screen anticancer drugs with tumor cell lines byMTT high throughout method.82%strains could produce high anticancer bioactive metaboliteagainst MCF-7tumor cell line. And six strains metabolite had good inhibition effect on MCF-7tumor cell and inhibited human embryo lung cells growth lightly at the same time.For A549and HeLa cells, strain15had more inhibitive activity. The IC50of72h for A549and HeLa cells were6.66μg/mL and14.70μg/mL respectively. So it was selected for futherinvestigation.The chromatography method had been studied and the suitable conditions had beendetermined and established. In the method, we used the Thermo ODS-2,5μm,250mm×4.6mmas HPLC column, acetonitrile: water=49:51as mobile phase.5components had been isolatedfrom the fermentation of strain15.Compound15-1had significant inhibition on breast cancer MCF-7cells. The inhibition ratesof compound15-1on breast cancer MCF-7cells was71.73%, which the concentration was100μg/mL and there was good dose-effect relationship The inhibition rates of the other compoundswere not obvious.91018-1had been isolated from the fermentation of strain91018which had anticanceractivity. The inhibition rates of compound91018-1on HeLa and MCF-7cells was69.19%and22.59%respectively when the concentration was100μg/mL. Compound91018-1had significantinhibition on breast cancer MCF-7cells.The H₂₂tumor bearing mice was collected and the anticancer rate was calculated. Resultsshowed the inhibition rate of compound91018-1was48.7%when the dosage was1.25mg/kg.More or less was not better for the inhibition rate. The inhibition rate of positive control whichwas cyclophosphamide was81.3%. But characteristic features of mice were worse. One mousewas dead on the8th day. The1.25mg/kg group had better characteristic features such as behavioractivity, hair and mental status.The expression of Bcl-2protein and p53protein in the tumor tissue were studied by theflow cytometry method. Results showed91018-1could induce tumor apoptosis by prevention ofcell cycle progression; Cells of S and G₂/M phase decreased. Cells were impeded at G₀/G₁phaseand thus affected DNA synthesis. The apoptosis was conducted by p53protein. We had utilized modern spectroscopy testing technology such as ESI, GCT-MS,¹H-NMR,¹³C-NMR and DEPT in order to confirm the structure of91018-1. After analyzing, we knew thatthe molecular weight of91018-1was487.68and the molecular formula was C₂₅H₃₃O₃N₃S₂. Thename of the compound is myxothiazol.