Objective:To analyze the expression of BTK and PKCβ in tumor cells of patients with multiple myeloma(MM) and normal human bone marrow lymphocytes. To explore the regulatory relationship between BTK and PKCβ and its influence on NF-kappa B. Methods:qRT-PCR and Western blotting was performed to detected the expression of BTK and PKCβ. Using the RNA interference, BTK's expression was reduced; using PCI-32765 BTK was inhibited; while overexpressing BTK in multiple myeloma cancer cells, PKCβ was inhibited. The changes of PKCβ was detected by qRT-PCR and Western blotting, and p65 nuclear distribution was detected by Western blot. Results:In 30 patients with multiple myeloma, BTK's positive rate was 30%, and compared with normal human bone marrow blood samples (positive rate was 5%), the difference was statistically significant. In addition, PKCβ's positive rate was 46.67%, compared with the normal bone marrow blood samples (positive rate was 15%), the difference was statistically significant. The expression of BTK were reduced or inhibited in human multiple myeloma cell line 8226, correspondingly, mRNA and protein expression of PKCβ were decreased. While the total protein expression of p65 did not change, p65 decreased in the nucleus. Overexpression of BTK could increase the expression of PKCβ and increase the distribution of p65 in nucleus, However, PKCβ inhibitor, LY333531, could reverse the over activation of NF-kappa B caused by overexpression of BTK. Conclusion:BTK and PKCβ are highly expressed in tumor cells of patients with multiple myeloma, BTK activates NF-kappa B by regulating PKCβ.
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