Research Of Low-level Laser Activated Death Receptor Pathway To Promote Apoptosis Of Colon Cancer RKO Cells

Objective:To study whether the expression of apoptotic factors in the RKO cell death receptor pathway of colon cancer was up-regulated under the condition of low-level laser,and to investigate the relationship of low-level laser therapy on apoptosis pathway of death receptor in RKO cells in colon cancer,To explore the effect of low-level laser therapy on apoptosis of rko cells in colon cancer and the possible mechanism,to provide the basis for the clinical treatment of low-level laser in colon cancer.Methods:Culture of RKO cells in colon cancer and selection of suitable cell concentrations:under the same conditions,RKO cells in colon cancer were cultured according to the beta-dilution method,and the activity of the cells was measured by MTS at the same time point,A significant statistically significant group of cells was selected as the suitable cell concentration for the experiment.Modelling of RKO cells in colon cancer with different doses of low-level lasers:the suitable cell concentrations were divided into five experimental groups:control group(0J/cm~2),experimental group(1J/cm~2,5J/cm~2,10J/cm~2,15J/cm~2),Grouped colon cancer RKO cells were respectively given low-level laser irradiation,regular observation and photo recording,At the same time node,the cells were treated by MTS,the cell activity of the group was measured and statistically analyzed.Detection of apoptosis genes in apoptosis pathway of death receptor in colon cancer RKO cells:After the constructed experimental model cells were cultured,total RNA was extracted.the expression of apoptotic genes tnfr1,tradd,caspase-8 at RNA level was determined by RT-PCR.the expression of apoptotic genes tnf-?,caspase-3at RNA level was determined by RT-q PCR.Results:Through the MTS experiment,the optimal experimental concentration of RKO cells in human colon cancer was12500 cells/well(P<0.01).Low-level laser energy density in different experiment group,control group(Con group:0J/cm~2)and experimental group(1J/cm~2,5J/cm~2,10J/cm~2,15J/cm~2),the MTS experimental test shows,RKO colon cancer cells with the increase of the energy density,measured the OD value also drops,at 15J/cm~2,RKO colon cancer cell survival than the control group significantly decreased(P<0.01);The control group and experimental group by RT-PCR test,detection of apoptosis pathway of TNFR1,TRADD,Caspase-8 three genes,the results suggest that with the increase of low-level laser energy density,three genes are raising trend,at 15J/cm~2,TNFR1,TRADD,Caspase-8 three genes in comparison with the control group have significantly higher(P<0.01);RT-q PCR test was used to detect two genes in the apoptosis pathway,TNF-?and Caspase-3.With the increase of low-level laser energy density,both genes showed up-regulation trend.At 15J/cm~2,both genes of TNF-?and caspase-3 were significantly up-regulated compared with the control group(P<0.01).The up-regulation trend of 5 genes was correlated with the down-regulation of OD value in MTS experiment.Conclusion:There is a tendency to promote apoptosis in colon cancer rko cells under low-level laser conditions,which may be related to the upregulation of gene expression related to death receptor apoptosis pathway after low-level laser irradiation,It is suggested that low-level laser therapy can activate the apoptosis pathway of death receptor and promote the apoptosis of colon cancer RKO cells.