Combined treatment of menadione and calcitriol increases the antiproliferative effect by promoting oxidative/nitrosative stress, mitochondrial dysfunction and autophagy in breast cancer MCF-7 cells

GUIZZARDI S; PICOTTO G; RODRÍGUEZ V; WELSH J.E; NARVÁEZ C; BOHL L; TOLOSA DE TALAMONI N

CANADIAN JOURNAL OF PHYSIOLOGY AND PHARMACOLOGY

NATL RESEARCH COUNCIL CANADA-N R C RESEARCH PRESS

Lugar: Otawa; Año: 2020

0008-4212

The aim of this study was to determine new insights into the molecular mechanisms involved in the antiproliferative action of menadione + calcitriol (MEN+D) on MCF-7 cells. MCF-7 cells were treated with either MEN, D or MEN+D. Cell cycle and mitochondrial membrane potential (ΔΨm) were measured by flow cytometry. Superoxide anion (O2-) and nitric oxide (NO?) contents were determined using spectrophotometry. Mitochondrial respiration was analyzed by directly measuring the oxygen consumption rate of live cells. Acidic vesicular organelles (AVOs) were detected with acridine orange. Cell migration was evaluated by the wound healing assay. MEN+D inhibited the cell growth after 24 h of treatment, which was not observed with each single treatment. The combined drugs reduced the mitochondrial respiration at that time, as judged by an increase in the proton leak and a decrease in the ATP generation and coupling efficiency. At longer times, 48 or 96 h, either D or MEN reduced the proliferation, but the effect was higher when both drugs were used together. The combined treatment increased the O2- and NO? contents as well as AVOs formation. The percentage of cells showing the lower ΔΨm was highly increased by the combined therapy. Cell migration was delayed by any treatment. In conclusion, the antiproliferative action of MEN+D involves oxidative/nitrosative stress, mitochondrial alteration and autophagy. This combined therapy could be useful to treat breast cancer cells because it inhibits multiple oncogenic pathways more effectively than each single agent.