Experimental study on forskolin combined with bortezomib inducing apoptosis in bortezomib-resistant multiple myeloma cells / 中国癌症杂志

ABSTRACT

Background and purpose:Although bortezomib has become one of the major therapeutic agents against newly diagnosed or relapsed multiple myeloma (MM), there are some patients who become resistant to bor-tezomib and then relapse, emerging as a major obstacle to long-term survival of MM patients. It has been found that elevation of intracellular cyclic adenosine monophosphate (cAMP) levels could induce cell cycle arrest and apoptosis in MM cells,which has become an interesting approach to MM therapy. This study aimed to investigate possible effects of forskolin combined with bortezomib on bortezomib-resistant myeloma cells and further explore its mechanisms. Methods:The bortezomib-resistant MM cell lines H929-R and primary cells from patients who do not respond to bortezomib were used asin vitro models. The inlfuences of bortezomib and/or forskolin on MM cells were evaluated through cellular morphology, changes of cell distribution and apoptotic rate. Meanwhile, lfow cytometry analysis was used to detect mitochondrial transmembrane potential (ΔΨm) and the expression levels of apoptosis regulators in these cells before and after the treatment were detected by Western blot.Results:Bortezomib (20 nmol/L) synergized with forskolin (50nmol/L) to induce apoptosis of H929-R cells and bortezomib-resistant primary cells. In addition, borte-zomib synergized with forskolin to induce collapse of mitochondrial transmembrane and facilitate the degradation of anti-apoptosis proteins including Bcl-2 and Mcl-1.Conclusion:Bortezomib could synergize with forskolin to induce apoptosis in bortezomib-resistant MM cells.