The Anti-cancer Effect And Preliminary Mechanism Of Purple Bacillus And Deoxy Violet Bacillus On Colon Cancer HT29 Cells

Research Background:Colorectal cancer(CRC)is one of the most common malignancy.In recent years,the morbidity and death rate of CRC have been in the rising trend.In CRC is the second and third most common malignancies among the global woman and man.In China,with the changes in people's diet and lifestyle,the incidence of CRC increased year by year,and tend to younger.At present,the main treatment for CRC is exairesis,supplemented with radiotherapy and chemotherapy and biological therapy.But the treatment effect.is usually not ideal.The adjuvant therapy can produces side effects.The patients have poor prognosis.The violacein and deoxyviolacein are blue-purple secondary metabolites of microorganisms,which have a strong ability to tint.The violacein and deoxyviolacein have anti-tumor activity,also can inhibit gram-positive bacteria and plant pathogen.In addition,violacein and deoxyviolacein are low-genotoxic substance,which can be used as colorant and preservative in food manufacture.Similarly,violacein and deoxyviolacein have a wide application prospect in the pharmaceutical industry.Objective:To evaluate the effect of violacein or deoxyviolacein on the apoptosis in HT29 cells and its possible mechanisms of anticancer effects.And to provide a theoretical basis for the clinical application of violacein and deoxyviolacein in the future.Methods:In vitro,human colon cancer HT29 cells were treated by violacein or deoxyviolacein in a series of concertrations.The absorbance value was detected by means of MTT assay and growth inhibition rate was calculate.The cellular morphology was observed under an inverted phase contrast microscope and transmission electron microscope.Cell cycle and apoptosis was assessed by flow cytometry.The expression of Bax,Bcl-2 and Caspase9 were analyzed by Western blotting.In addition,we examined whether the proteins of Beclin-land p62 are involved in the regulation of violacein-induced or deoxyviolacein-induced autophagy.Result:Both violacein and deoxyviolacein could inhibit the growth of human colon cancer HT29 cells in a dose-dependent manner.The morphological changes of the cells were observed in the cytoplasm after the intervertebral phase contrast microscope.A large number of different sizes of vacuoles,cell vacuoles with the increase in drug concentration gradually increased and increased.With the increase of drug concentration,the proportion of cells in G0/G1 phase increased significantly,and the proportion of S phase was significantly decreased.Both violacein and deoxyviolacein could increase the percentage of apoptosis in HT29 cells,and the expression of apoptotic protein Caspase9 and Bax And the expression of Bcl-2 was up-regulated,and the expression of Bcl-2 was up-regulated by transmission electron microscopy.The expression of autophagy protein Beclinl increased in the HT29 cells after the treatment with violacein or deoxyviolacein.Conclusion:Both violacein and deoxyviolacein could inhibit the growth of human colon cancer HT29 cells and induce apoptpsis and autophagy.The mechanism may be associated with mitochondria mediated endogenous pathway.The proteins of Beclin-1 was involved in the regulation of violacein-induced and deoxyviolacein-induced autophagy.