P18 - The effect of resveratrol on signal transduction pathways and the role of pro-apoptotic Bax protein on apoptosis in HCT- 116 colon carcinoma cell lines

Abstract

Colon carcinoma is the third among the cancer related deaths. The role of pro-apoptotic Bax protein on the resveratrol related apoptosis, mitochondrial membrane potential and signal pathways has not been identified in colon carcinoma cells. In this direction, HCT-116 bax positive and HCT-116 negative cell lines were utilized to detect the apoptotic effect and I?B, MEK1 and STAT 3 signal transduction pathways of resveratrol. The impact on the cell viability and IC50 value of resveratrol has been determined via WST-1 viability assay. The ratio of apoptosis has been evaluated via flow cytometry following Annexin V/Propidium iodide (PI) double staining. Changes in the mitochondrial membrane potential have been analyzed by flow cytometry and JC-1 fluorometric staining. IkB, MEK1 and STAT3 molecules were measured by Enspire device. Data showed the IC50 value for resveratrol as 50M. According to the flow cytometry, apoptosis ratio has been determined as 29.65% in the experimental group of bax positive cells, as 13.98% in the experimental group of bax negative cells. Changes in the membrane potential has been established as 8.62% in the experimental group of bax positive cells, as 97.98% in the experimental group of bax negative cells. When the obtained data from Enspire device was reviewed; bax positive cells I?B phosphorylations were found as as 5.22 for experimental groups; MEK1 phosphorylations were found as and as 1.15 for experimental groups; STAT 3 phosphorylations were found as and as 2.52 for experimental groups. In HCT-116 bax negative cells, I?B phosphorylation were and 2.71 in experimental groups; MEK1 phosphorylation were 1.18 in experimental groups; STAT 3 phosphorylation were 1.54 in experimental groups. Our data show that Bax protein plays role in the apoptotic effect of resveratrol by altering mitochondrial membrane potential and mitochondrial membrane permeability, signal transduction and the absence of Bax increase the sensitivity of HCT-116 colon carcinoma cells to apoptosis.