Angéla Takács1, Eszter Lajkó1, Ildikó Istenes2, László Kőhidai1, Orsolya Láng1
1 Department of Genetics Cell- and Immunobiology, Semmelweis University, Budapest Hungary
2 1st Department of Internal Medicine, Semmelweis University, Budapest, Hungary
Introduction: Bortezomib is a proteasome inhibitor chemotherapeutic agent used to treat multiple myeloma; recent studies offer it as a promising drug to treat melanoma. Bortezomib-induced peripheral neuropathy (BIPN) is a dose-limiting side-effect, that can be treated with antioxidants, e.g. alpha-lipoic acid and thiamine.
Aims: The objective of our experiments was: to verify the cytotoxicity of bortezomib; to test and compare the influence of the antioxidants on the antitumor effect of bortezomib in melanoma and myeloma cells.
Method: The U266 myeloma and A2058 metastatic melanoma cell lines were treated with the following concentrations: (i) bortezomib: 20, 100 and 300 ng/mL; (ii) alpha-lipoic acid: 10 and 100 µg/mL (iii) thiamine: 150 and 300 nM. Impedimetry (xCELLigence SP) was used to evaluate the cytotoxicity. Cell cycle profile and apoptosis were analyzed by flow cytometry after propidium iodide staining, annexin-V assay and phospho-p53 immunostaining. Cell morphological changes were investigated by holographic microscopy (HoloMonitor® M4).
Results: Bortezomib was cytotoxic and triggered p53 activation in both cell lines. Alpha-lipoic acid enhanced the cytotoxicity of bortezomib (20 ng/ml) in U266 cells, but counteracted the cytotoxicity of bortezomib in melanoma cells and decreased the level of active p53. Thiamine (300 nM) antagonized the antitumor effect of bortezomib on myeloma cells. A2058 cells were arrested in G2/M phase by 300 ng/ml bortezomib and this effect was blocked by 300 nM thiamine. In both cells, bortezomib was apoptotic and drastically influenced the morphology of the cells whilst the antioxidant co-treatment inhibited the development of this activity.
Conclusion: The combination therapy of bortezomib and a low dose of antioxidants could be offered for the treatment of multiple myeloma in case of BIPN, while for the treatment of melanoma every combination should be avoided.
Doctoral School: Pharmaceutical Sciences
Program: Modern Trends in Pharmaceutical Scientific Research
Supervisor: László Kőhidai, MD, PhD, Med. Habil., Assoc. Professor; Orsolya Láng, MD, PhD; Eszter Lajkó PharmD, PhD;
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