A Study Of Pancreatic Cancer PANC-1 Cells Apoptosis Induced By DRE Combined With NaHCO₃

Objective:Pancreatic cancer is a kind of digestive tract malignant tumor with very poor therapeutic effect and prognosis.Dandelion root extract（DRE）has a good inhibitory effect on various cancer cells.At present,there are few reports about DRE in the treatment of pancreatic cancer,and the specific mechanism of DRE induced pancreatic cancer apoptosis is still unclear.In addition,as a basic compound,NaHCO₃ can reduce lactic acid content in tumor microenvironment and improve the sensitivity of tumor cells to glucose.Therefore,we studied the effects of DRE,DRE combined with NaHCO₃ on PANC-1 cells and explored the corresponding mechanism.Methods:DRE was obtained by soxhlet extractor.PANC-1 cells were treated with DRE,DRE+NaHCO₃ respectively.Cytotoxicity was detected by CCK-8 assay;Cell proliferation was detected by cell counting assay;Cell cycle,the apoptosis rate,MMP（mitochondrial membrane potential）and ROS（reactive oxygen species）level were detected by flow cytometry;Extracellular lactic acid concentration was detected by ultraviolet spectrophotometer;Caspase-3 activity was detected by Western blot and colorimetry method;The expression levels of Bax,Bcl-2,Cytochrome C,Caspase-9 and PARP were detected by Western blot and ELISA methods;DNA fragmentation and DNA concentration were detected by agarose gel electrophoresis and Qubit^TM 4fluorescence spectrometer respectively;The changes of cellular biomacromolecules were detected by FTIR microspectroscopy.Results:DRE had cytotoxicity to PANC-1 cells.It blocked cell cycle,inhibited cell proliferation,induced the opening of mitochondrial membrane pore and the release of Cytochrome C by changing the expression levels of Bcl-2 and Bax proteins,which led to the decrease of MMP and the activation of Caspase family proteins,and eventually led to apoptosis.In addition,the addition of NaHCO₃ could neutralize intracellular lactic acid and reduce the glucose tolerance of cancer cells,which enhanced the effect of DRE on pancreatic cancer cells.IR spectra showed that DRE mainly caused the damage to intracellular proteins and nucleic acids,and the damage was more serious in the combined treatment group.Conclusion:DRE may damage mitochondria and eventually lead to apoptosis by affecting the expression of related proteins in mitochondrial pathway.In addition,the combination of NaHCO₃ and DRE can induce apoptosis in the same way as DRE action and improve the effect of DRE.IR spectra reveals biochemical changes in apoptosis at molecular level,which provides a powerful supplement for the further study of the apoptosis mechanism.