Study On The Mechanism Of ITGB2 Influencing MHC-I Expression Through Calreticulin In Triple Negative Breast Cancer

Objective: to explore the mechanism of the effect of integrin β-2 on the expression of MHC-I in triple negative breast cancer through calreticulin.Methods: MDA-MB-231 cell lines stabilized by ITGB2 overexpression and silencing lentivirus were constructed.The expression of calreticulin mRNA was detected by qRT-PCR,the localization and expression of calreticulin was observed by immunofluorescence,and the expression of calreticulin was detected by Western blotting(WB).Results:(1)qRT-PCR results showed that the expression level of calreticulin mRNA in ITGB2 overexpression group(1.688 ±0.101)was significantly higher than that in blank control group(1.007 ±0.148).(2)Immunofluorescence results showed that the expression level of calreticulin in ITGB2 overexpression group(54.117 ±4.047)was significantly higher than that in blank control group(42.407 ±3.863).(3)Immunofluorescence assay showed that calreticulin was mainly distributed in the cytoplasm and cell membrane in the ITGB2 overexpression group,while in the blank control group,calreticulin was mainly distributed in the cytoplasm in clusters,and the difference was statistically significant.(4)WB assay showed that the expression level of calreticulin in ITGB2 overexpression group(0.662±0.038)was significantly higher than that in blank control group(0.410±0.022).Conclusion: the high expression of ITGB2 in TNBC can affect the translocation of calcium reticulum from endoplasmic reticulum to the cell membrane,thus hinder the assembly and processing of MHC-I molecules,and then affect the expression of MHC-I on the cell membrane.