Gene expression profiles in human and mouse primary cells provide new insights into the differential actions of vitamin D3 metabolites.

1α,25-Dihydroxyvitamin D3 (1α,25(OH)2D3) had earlier been regarded as the only active hormone. The newly identified actions of 25-hydroxyvitamin D3 (25(OH)D3) and 24R,25-dihydroxyvitamin D3 (24R,25(OH)2D3) broadened the vitamin D3 endocrine system, however, the current data are fragmented and a systematic understanding is lacking. Here we performed the first systematic study of global gene expression to clarify their similarities and differences.

Progestins regulate genes that can elicit both proliferative and antiproliferative effects in breast cancer cells.

Sex steroid hormone progesterone is known to have profound effects on the growth and differentiation of the normal mammary gland and malignant breast epithelial cells. In vitro progesterone and synthetic progesterone-like compounds (progestins) inhibit breast cancer cell growth. Medroxyprogesterone acetate (MPA) is a synthetic hormone widely used in the adjuvant treatment of advanced breast cancer, hormone replacement therapy and in oral contraceptives.

Distribution of lipid nanocapsules in different cochlear cell populations after round window membrane permeation.

Hearing loss is a major public health problem, and its treatment with traditional therapy strategies is often unsuccessful due to limited drug access deep in the temporal bone. Multifunctional nanoparticles that are targeted to specified cell populations, biodegradable, traceable in vivo, and equipped with controlled drug/gene release may resolve this problem. We developed lipid core nanocapsules (LNCs) with sizes below 50 nm.

Interaction of nuclear receptors with hsp90 in living cells.

The ubiquitous heat shock protein 90 (hsp90) has been shown to participate directly in the function of a wide variety of cellular signal transduction components, including steroid receptors (SRs). However, there is still no direct evidence for an in vivo association of SRs with hsp90. This study utilizes the mammalian two-hybrid system to study the ability of hsp90 to interact with various (non)liganded nuclear receptors (NRs) in vivo in mammalian cells.

Role of 24-hydroxylase in vitamin D3 growth response of OVCAR-3 ovarian cancer cells.

Vitamin D and its analogues are potent regulators of cell growth and differentiation both in vivo and in vitro. We studied the effects of 25-hydroxyvitamin D(3) [25(OH)D(3)], 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] and vitamin D analogue, EB 1089, on the growth of a human ovarian cancer cell line, OVCAR-3. We also studied the expression of vitamin D metabolising enzymes 24-hydroxylase (24OHase) and 1alpha-hydroxylase (1alphaOHase).

Regulation of nuclear receptor and cofactor expression in breast cancer cell lines.

Objective: The aim of this study was to compare the expression profile of nuclear receptors (NRs) and cofactors in different breast cancer cell lines as well as their regulation by estradiol, insulin and progestin R5020.

Methods: Expression of NRs and cofactors were determined from MCF-7, T-47D and ZR-75-1 breast cancer cell lines. Multiprobe ribonuclease protection assay and real-time RT-PCR were used to quantitate mRNA levels of steroid receptors, vitamin D receptors (VDR) and retinoic acid receptors (RAR) and cofactors: amplified in breast cancer-1, cyclic AMP response element binding protein (CBP), p300/CBP-associated factor, p300, nuclear receptor corepressor and silencing mediator of repressed transcription.

Progestin and G protein-coupled receptor 30 inhibit mitogen-activated protein kinase activity in MCF-7 breast cancer cells.

We have previously shown that the G protein-coupled receptor (GPR)30 is critical for progestin-induced growth inhibition. In this study, we addressed signal transduction pathways involved in progestin-mediated signaling. Progestin could not provide any additional growth inhibitory effect to MCF-7 cells treated with specific MAPK kinase inhibitors, PD98059 and U0126.

G protein-coupled receptor 30 is critical for a progestin-induced growth inhibition in MCF-7 breast cancer cells.

The issue of how progesterone affects mammary gland growth is controversial, and the mechanism governing the effects of the hormone remains mostly unknown. We have previously shown that G protein-coupled receptor 30 (GPR30) is a progestin target gene whose expression correlates with progestin-induced growth inhibition in breast cancer cells. In this study, we investigate the role of GPR30 in regulating cell proliferation and mediating progestin-induced growth inhibition.