Study Of PANC-1 Cells Apoptosis Of Pancreatic Cancer Induced By Epigallocatechin-3-gallate Via PI3K-Akt Signaling Pathway

ObjectiveWe study apoptosis of the PANC-1 cells of the pancreatic cancer (PCPC) and the effect on PI3K-Akt signaling pathway induced by Epigallocatechin- 3-gallate(EGCG) in order to explore the mechanism of apoptosis of pancreatic cancer cells induced by the EGCG via PI3K-Akt signaling pathway.Methods1. PCPC was cultivated in vitro and was inhibited by different concentrations of EGCG(0μg/mL, 25μg/mL, 50μg/mL, 75μg/mL, 100μg/mL), respectively. PCPC was divided into different groups based on different concentrations of EGCG .The growth of PCPC was observed by inverted phase contrast microscope after the treatment was completed at 12, 24, 36 and 48hours, respectively.2. The survival rate of pancreatic cancer cells was detected by MTT assay under the different concentrations of EGCG(0μg/mL, 25μg/mL, 50μg/mL, 75μg/mL, 100μg/mL) and intervention time was 12, 24, 36 and 48 hours respectively.3. Applying the flow-cytometry analysis, the extent of apoptosis of pancreatic cancer cells was quantified with annexin V and PI under the treatment with different concentrations of EGCG after 24 hours of intervention.4. The expression of Akt, p-Akt, Caspase-3, Bcl-2 and Bax was analyzed by Western blotting respectively.Results1. The observation with inverted phase contrast microscope was showed that the inhibitory effect of EGCG on the proliferation of pancreatic cancer cells was found significantly when the concentration of EGCG was more than 25μg/mL and when the intervention time achieved at 24 hours.2. With the increase in concentration of EGCG and extension of the intervention time, the effect of EGCG inhibition on the growth of PANC-1 cells becomes gradually stronger and has a clearly time-dose dependent. The survival rate of pancreatic cancer cells was(73.162.82)%(P<0.05)when the concentration of EGCG was more than 50μg/mL at 24 hours. However, the inhibition of the survival rate of pancreatic cancer cells was maximum when the concentration of EGCG is 100μg/mL at 48 hours.3. As shown by the flow cytometer, the apoptosis rate of pancreatic cancer cells could be induced by EGCG in a dose-dependent manner. And the most of apoptosis changes occurred in earlier period of the apoptosis.4. The result of Western blotting indicated that after 24hours of the EGCG intervention, with the increase in concentration of EGCG , the expression of p-Akt and Bcl-2 proteins was gradually reducing and was down-regulated in a dose-dependent manner(P<0.05). The expression of Akt protein didn't change(P>0.05). The expression of Caspase-3 and Bax proteins was up-regulated(P<0.05). The ratio of Bax/Bcl-2 increased in a dose- dependent manner(P<0.05).Conclusion1. The proliferation of PCPC can be inhibited by EGCG in a dose-dependent manner.2. The apoptosis of PCPC can be induced by EGCG.3. In the PI3K-Akt signaling pathway of PCPC, phosphorylation of Akt had been inhibited. The expression of p-Akt and Bcl-2 proteins was down-regulated. The expression of Caspase-3 and Bax proteins was up-regulated.