Antioxidants Abrogate Alpha-Tocopherylquinone-Mediated Down-Regulation of the Androgen Receptor in Androgen-Responsive Prostate Cancer Cells.

Tocopherylquinone (TQ), the oxidation product of alpha-tocopherol (AT), is a bioactive molecule with distinct properties from AT. In this study, AT and TQ are investigated for their comparative effects on growth and androgenic activity in prostate cancer cells. TQ potently inhibited the growth of androgen-responsive prostate cancer cell lines (e.

The SRD5A2 V89L polymorphism is associated with severity of disease in men with early onset prostate cancer.

Background: Emerging evidence indicates that testosterone (T), and not dihydrotestosterone (DHT), is the most relevant androgen that promotes carcinogenesis in the prostate. Steroid 5-alpha reductase type II (SRD5A2) catalyzes the irreversible conversion of T to DHT in male reproductive organs. Because the SRD5A2 gene is highly polymorphic at codon 89, two SRD5A2 isoforms are expressed that differ in K(m) and V(max) values.

Estrogen receptors alpha (ESR1) and beta (ESR2) are expressed in circulating human lymphocytes.

Bone marrow thymocytes in part mediate the bone-preserving effects of estrogen by decreasing their production of osteoclast growth factors such as interleukin-1 and -6 and tumor necrosis factor alpha in the presence of physiological amounts of estradiol. Although several in vitro studies implicate the T-lymphocyte as a candidate mediator of estrogen signaling in the skeleton, whether these cells or any lymphocytes ordinarily express one or both nuclear estrogen receptors was previously unresolved. The purpose of our investigation was therefore to ascertain, by using real-time PCR, immmunoblotting, and cytometric techniques, if any of the nuclear estrogen receptors could be detected in normal peripheral blood mononuclear cells (PBMNC) collected from healthy volunteers.

Serum leptin levels, bone mineral density and osteoblast alkaline phosphatase activity in elderly men and women.

Although primarily secreted by adipose cells, leptin, a polypeptide hormone that influences body weight, satiety and lipid metabolism, and its receptor are also expressed in human osteoblasts. Leptin plays a role in the central, hypothalamic modulation of bone formation, as well as locally within the skeleton by enhancing differentiation of bone marrow stroma into osteoblasts and inhibiting its differentiation into osteoclasts and adipocytes. The purpose of this investigation was to compare serum leptin values in 100 postmenopausal women (age 62-97) and 31 men (age 72-92) to bone mineral density (BMD) measurements made by dual X-ray absorptiometry and additionally to biochemical markers of bone resorption and formation, including crosslinked collagen N-telopeptides (NTx), aminoterminal extension procollagen propeptides (PINP) and bone-specific alkaline phosphatase (bAP).