Mitotane Inhibits Proliferation and Affects Mitochondrial Metabolism in Human Breast, Lung and Colon Cancer Cell Lines _ Tumorigenesis, Metastasis, and Therapies for Cancer.pdf (523.27 kB)
Mitotane Inhibits Proliferation and Affects Mitochondrial Metabolism in Human Breast, Lung and Colon Cancer Cell Lines _ Tumorigenesis, Metastasis, and Therapies for Cancer.pdf
posted on 2016-11-27, 12:37authored bySalvador J. Diaz-CanoSalvador J. Diaz-Cano, Dorota Dworakowska, Paulina Szyszka, Urszula Waszut, Gregory Weitsman, Melvyn Smith, Salvador J Diaz-Cano, Jane Moorhead, Simon J B Aylwin, Krzysztof Sworczak, Stefan Richard Bornstein and Tony Ng
Mitotane
acts specifically on adrenocortical tissue and is used as a standard
treatment in adrenocortical cancer. The exact mechanism of its action
remains unknown, despite its clinical use for more than 60 years.
Recently it has been suggested that in human adrenocortical cancer
cells, mitotane alters mitochondrial respiratory chain activity by
inducing cytochrome c oxidase defect.
The
aim of the study was to assess the effect of Mitotane on proliferation,
apoptosis and mitochondrial metabolism in human breast (MCF7), lung
(H1975) and colon (HKe-3) cancer cell lines and compare it with our
previous results in human adrenocortical cancer (H295R).
The
proliferation rate of cells was assessed by the resazurin assay. The
apoptosis induction was determined by the caspase-3-like activity assay.
Changes in expression of the 84 genes involved in mitochondrial
metabolism (Complex I: NADH-Coenzyme Q Reductase; Complex II:
Succinate-Coenzyme Q Reductase; Complex III: Coenzyme Q-Cytochrome c
Reductase; Complex IV: Cytochrome c Oxidase; Complex V: ATP Synthase)
were assessed using Mitochondrial Energy Metabolism Plus PCR Arrays,
Qiagen.
Optimum cytotoxic effects of
Mitotane were observed after 24 and 48 hours incubation for H295R cells
and HKe-3, MCF7, H1975; respectively. In the H295R cell line a 10uM
concentration of Mitotane resulted in 27.0±0.9% cytotoxicity, whereas in
HKe-3, MCF7 and H1975 cell lines concentration of 40uM caused
cytotoxicity of 48.5±5.2%; 40.2±2.5% and 28.6±2.1%, respectively. 100%
cytotoxicity was achieved at a concentration of 20uM for H295R and 100uM
for HKe-3, MCF7, and H1975. Cytotoxic effects were negatively
influenced by the number of cells/well in H295R, HKe-3, and H1975 but
not in MCF7. Although Mitotane had a strong cytotoxic effect on all
tested cell lines, caspase-3 activity was induced only in H295R cell
line. Expression levels of several genes involved in mitochondrial
metabolism were changed by Mitotane; however, different genes were
affected in different cell lines. Of 84 genes investigated, mRNA levels
were decreased/increased by >2 folds in 18/4; 10/29; 6/7 and 28/2 in
H295R, HKe-3, MCF7, and H1975, respectively.
Mitotane
exhibits antiproliferative activity in breast, colon and lung cancer
cell lines. It affects mitochondrial metabolism regardless of the type
of cancer and hence his cytotoxic effect is not only accurate to the
adrenal cortex.