RESUMO
Objective:To explore the mechanism by which GSDME promoter methylation regulates the chemotherapy sensitivity of breast cancer (BC) cells through pyrolysis.Methods:Tissues of 54 cases with BC treated with chemotherapy were collected and divided into chemotherapy resistant group and sensitive group. Docetaxel (DTX) was used to treat BC cells to establish drug-resistant BC cells. CCK8 was used to detect cell resistance.qRT-PCR was used to detect the expression of GSDME in tissues and cells. Then sulfite sequencing method was utilized to determine the methylation level of the GSDME promoter methylation site. The expression level of GSDME in DTX-treated BC cells was intervened, and qRT-PCR was used to detect the expression level of Caspase-1, Caspase-4, IL-1β, and IL-18 in cells to assess the degree of cell pyrolysis.Results:Compared with the chemotherapy sensitive group, the expression of GSDME was down-regulated in the chemotherapy resistant group ( t=6.54, P<0.001) . Compared with MCF-10A cells, Caspase-1 ( t=9.14, P<0.001) , Caspase-4 ( t=9.35, P<0.001) , IL-1β ( t=6.13, P=0.004) , and IL-18 ( t=5.49, P=0.005) expression level in MCF-10A/DTX cells were decreased, however, the above indicators were up-regulated after overexpression of GSDME in MCF-10A/DTX cells. Hypermethylation in GSDME promoter region led to a decrease in mRNA expression ( t=12.56, P<0.001) . In tolerance tissues, the methylation level in the GSDME promoter region was negatively correlated with the mRNA level ( r=-0.57, P=0.010) . After treating MCF-10A/DTX cells with 5-azacytidine, a methylation inhibitor,Caspase-1, Caspase-4, IL-1β, IL-18 levels were significantly increased, and GSDME level were up-regulated. Conclusion:Hypermethylation in the promoter region of GSDME leads to decreased mRNA expression, inhibits pyrolysis of BC cells, and reduces the sensitivity of DTX chemotherapy.
RESUMO
Objective To investigate effect to kill primary breast cancer cells by dendritic cell (DC)with self-freeze thawing antigens of primary breast cancer cells co-cultured with cytokine induced killer cell (CIK). Methods Self-neoplasm antigen by primary cells of breast cancer in log phase growth was prepared and DC and CIK cells was cultured from peripheral blood. The CIK of co-cultured DC loaded self-neoplasm antigen was compared to PBMC, CIK cells with self-neoplasm antigen and the single CIK cells. Results Killing efficiency of PBMC, CIK, Ag-CIK and Ag-DC-CIK were (34.35±3.28) %, (45.91±2.78) %, (50.88±3.22) %, (62.10±5.94) %. There were significant difference between Ag-DC-CIK group and CIK-Ag and CIK group to primary cells of breast cancer (P <0.01). Conclusion The CIK induced from cocultured DC loaded with self-neoplasm antigen show a special killing activity to self-primary tumor cells.