Tissue-Selective Regulation of Aromatase Expression by Calcitriol: Implications for Breast Cancer Therapy

Efficacy of a combined alendronate and calcitriol agent (Maxmarvil^®) in Korean postmenopausal women with early breast cancer receiving aromatase inhibitor: a double-blind, randomized, placebo-controlled study

“…also results in enhanced tumor inhibition [11]. This makes calcitriol a favorable choice for combination with alendronate considering the status of our patients with respect to the recurrence of breast cancer.…”

“…For the estimation of the number of subjects, the diftumor inhibition [11]. We have previously shown that the combinative alendronate (5 mg) and calcitriol (0.5 µg) agent (Maxmarvil ® , Yuyu Co., Seoul, Korea) is quite effective in maintaining bone mass in Asian osteoporotic postmenopausal women, even though the daily dosage of alendronate approved by the USA Food and Drug Administration is 10 mg [12].…”

Tissue-Specific Regulation of Sex Hormone Biosynthesis and Metabolism: Novel Aspects on Hormonal Signalling and Maintenance of Cellular Steroid Levels

“…Interestingly, it was recently reported that 1,25-dihydroxyvitamin D 3 regulates the expression of aromatase in a tissue-selective manner. Thus, calcitriol significantly decreased aromatase expression in human breast cancer cells and adipocytes but caused increased aromatase expression in human osteosarcoma cells and ovarian cancer cells (Krishnan et al, 2010). Calcitriol exerts cell line-specific effects on both estrogen and androgen metabolism, including the production of estrogens and androgens .…”

“…1), were found to be altered by 1,25-dihydroxyvitamin D 3 treatment . Accumulated data have revealed that sex hormone biosynthesis and metabolism may be regulated by vitamin D (Barrera et al, 2007;Krishnan et al, 2010;Lou et al, 2005;Tanaka et al, 1996). Important reactions in the metabolism of androgens and estrogens are catalyzed by 5-reductase and aromatase (CYP19A1) (Fig.…”

“…Vitamin D seems to be involved in the control also of prostate cancer cell growth (Flanagan et al, 2010;Tuohimaa et al, 2005). Analysis of effects of 1,25-dihydroxyvitamin D 3 on aromatase promoter activities revealed differences between NCI-H295R cells and MCF-7 cells, where promoter I.3 and promoter I.4 were stimulated and promoter II were down regulated in NCI-H295R cells while all three promoters are down regulated in breast cancer MCF-7 cells (Krishnan et al, 2010). The findings that 1,25-dihydroxyvitamin D 3 specifically down regulates aromatase gene expression and activity and decreases production of estradiol in breast cancer cells are interesting in the context of 1,25-dihydroxyvitamin D 3 as an anti cancer agent (Krishnan et al, 2010 .…”