Primary Study On The Influence Of β 3GnTs Expression Induced By As₂O₃ In Breast Cancer Cells And The Relationship Between β 3Gnt8 And Transcription Factor C-jun

Object Observe the inhibition of As₂O₃ (arsenic trioxide) with different concentrations on breast cancer cells growth, the apoptosis inducing function on the cell and the effect onβ3GnT2 andβ3GnT8 expression with different concentrations arsenic trioxide. Initially discuss the mechanism of As₂O₃ inducing apoptosis. It is also reported that there have been some relationships between glycosyltransferases and the transcription factor c-jun. This thesis also aims to study the relationship of them in breast cancer cells.Methods: The effect of As₂O₃ on the growth of breast cancer cell line MDA-MB-231 and MCF-7 was observed after applying different concentrations As₂O₃ in vitro. The inhibitory effect of As₂O₃ on the cell proliferation was investigated with 3-(4,5-dimethyl2thizazol-2-yl)-2,5-diphenyl tetrazolium bromide(MTT) and Hoechst33258; RT-PCR was adopted to detect mRNA expression ofβ3GnT2 andβ3GnT8. Western Blot was used to detect express status of related protein. Chromatin Immunoprecipitation was used to detect the relationships ofβ3GnT2 gene,β3GnT8 gene and transcription factor c-jun. Immunoprecipitation was used to detect the orientational expression of transcription factor c-jun, andβ3GnT2 andβ3GnT8 in breast cancer cells.Results: Compared to control group,different concentration As₂O₃ could induce the breast cancer cells apoptosis, and its inhibition strengthened along with dosage increasing, assuming the dose dependence. There was a significant difference of mRNA expression among anyβ3GnT2,β3GnT8 group and the negative control. The protein express status detected by Western Blot was in accordance with the level of mRNA.β3GnT2 andβ3GnT8 gene can be amplified in the product of Chromatin Immunoprecipitation. As immunofluorescence assay indicated, andβ3GnT2,β3GnT8 are expressed in the breast cancer cells and had the overlapped part.Conclusion: As₂O₃ can exert obvious inhibitory effect on MDA-MB-231 and MCF-7 cell growth in vitro.The inhibitory effect increases with dosage escalation and shows dosage dependence.As₂O₃ can induce the MDA-MB-231 and MCF-7 cell apoptosis,also the apoptosis effect and the dosage assume the positive correlation. As₂O₃ regulatsβ3GnT2 andβ3GnT8 expression down. We suggested transcription factor c-jun may have influence on the expression ofβ3GnT8. Transcription factor c-jun may have influence on the expression ofβ3GnT8.