Degradation of gelsolin in pancreatic cancer cell lines by ubiquitin-proteasome pathway / 基础医学与临床

ABSTRACT

Objective To explore the role of ubiquitin-proteasome pathway for the gelsolin protein degradation in pancreatic cancer.Methods Pancreatic cancer cell lines BxPC-3 and PANC-1 were first treated with specific 26s proteasome inhibitor lactacystin.Immunoblots of cell lysates were probed for gelsolin expression.To determine whether gelsolin was conjugated to ubiquitin,proteins extracted from the cells with or without lactacystin were immunoprecipitated with anti-gelsolin antibody,followed by Western blot analysis.Results The expression of gelsolin protein increased obviously after treatment with lactacystin in BxPC-3 cells for 12 h.Using anti-gelsolin antibody to immunoprecipitate gelsolin protein and followed by Western blot using anti-ubiquitin monoclonal antibody,it was found that inhibition of proteasome pathway by lactacystin resulted in accumulation of ubiquitylated forms of gelsolin protein.In PANC-1 cell line,there was no significant changes of gelsolin after treatment with lactacystin.Conclusion Ubiquitin-proteasome dependent degradation may be an important regulatory mechanism for gelsolin down-regulation in pancreatic cancer cells.