Background: Triple-negative breast cancer (TNBC) is an aggressive form of breast cancer that disproportionately affects women with darker skin. Epidemiological studies indicate that higher vitamin D levels prevent incidence of TNBC and translate to higher survival rates in those that have TNBC.
Materials and methods: The growth inhibition effects of two forms of vitamin D were assessed in MCF-7 and three TNBC lines using CellTiter-Glo. Expression of vitamin D-metabolizing enzymes was measured after vitamin D treatment by quantitative reverse transcription polymerase chain reaction (RT-qPCR).
Results: MCF-7 was growth inhibited by vitamin D at high concentrations but the TNBC lines were not. All cell lines demonstrated large increases in CYP24A1 mRNA levels under vitamin D treatment but there was little change in CYP27B1 or VDR mRNA levels.
Conclusion: These TNBC cell lines are resistant to growth inhibition by vitamin D. This could be due to large inactivation of vitamin D by CYP24A1 or by another mechanism.
Keywords: 25-hydroxyvitamin D; Breast cancer; CYP24A1; CYP27B1; triple-negative breast cancer; vitamin D; vitamin D receptor.
Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.