27-hydroxycholesterol and DNA damage repair: implication in prostate cancer.

Introduction: We previously reported that cholesterol homeostasis in prostate cancer (PC) is regulated by 27-hydroxycholesterol (27HC) and that CYP27A1, the enzyme that converts cholesterol to 27HC, is frequently lost in PCs. We observed that restoring the CYP27A1/27HC axis inhibited PC growth. In this study, we investigated the mechanism of 27HC-mediated anti-PC effects.

27-Hydroxycholesterol Impairs Plasma Membrane Lipid Raft Signaling as Evidenced by Inhibition of IL6-JAK-STAT3 Signaling in Prostate Cancer Cells.

We recently reported that restoring the CYP27A1-27hydroxycholesterol axis had antitumor properties. Thus, we sought to determine the mechanism by which 27HC exerts its anti-prostate cancer effects. As cholesterol is a major component of membrane microdomains known as lipid rafts, which localize receptors and facilitate cellular signaling, we hypothesized 27HC would impair lipid rafts, using the IL6-JAK-STAT3 axis as a model given its prominent role in prostate cancer.

Serum Lipids prior to Starting Androgen Deprivation Therapy and Risk of Castration Resistant Prostate Cancer and Metastasis: Results from the SEARCH Database.

Purpose: We tested the association of serum lipid levels prior to androgen deprivation therapy with the risk of castration resistant prostate cancer and metastasis.

Materials And Methods: We identified 302 men in the SEARCH (Shared Equal Access Regional Cancer Hospital) database who received androgen deprivation therapy after radical prostatectomy for nonmetastatic disease, had never received statins before androgen deprivation therapy and had available serum lipid data within 2 years prior to androgen deprivation therapy. Cox proportional hazards models were used to test associations between total cholesterol (less than 200 vs 200 mg/dl or greater), low density lipoprotein (less than 130 vs 130 mg/dl or greater), high density lipoprotein (40 or greater vs less than 40 mg/dl) and triglycerides (less than 150 vs 150 mg/dl or greater) and the risk of castration resistant prostate cancer and metastasis after androgen deprivation therapy while adjusting for potential confounders.

The miR-183 family cluster alters zinc homeostasis in benign prostate cells, organoids and prostate cancer xenografts.

The miR-183 cluster, which is comprised of paralogous miRs-183, -96 and -182, is overexpressed in many cancers, including prostate adenocarcinoma (PCa). Prior studies showed that overexpression of individual pre-miRs-182, -96 and -183 in prostate cells decreased zinc import, which is a characteristic feature of PCa tumours. Zinc is concentrated in healthy prostate 10-fold higher than any other tissue, and an >80% decrease in zinc is observed in PCa specimens.

microRNAs and DICER1 are regulated by 1,25-dihydroxyvitamin D in prostate stroma.

Vitamin D deficiency increases the risk of lethal prostate adenocarcinomas (PCa) and the majority of older men are deficient. Although PCa arises from the epithelium, the surrounding stroma has hormonal regulatory control over the epithelium and contributes to carcinogenesis. Herein, we describe regulation of microRNAs (miRs) by the active hormone dihydroxyvitamin D (1,25(OH)D) in human prostate stroma.

Evidence for Feedback Regulation Following Cholesterol Lowering Therapy in a Prostate Cancer Xenograft Model.

Background: Epidemiologic data suggest cholesterol-lowering drugs may prevent the progression of prostate cancer, but not the incidence of the disease. However, the association of combination therapy in cholesterol reduction on prostate or any cancer is unclear. In this study, we compared the effects of the cholesterol lowering drugs simvastatin and ezetimibe alone or in combination on the growth of LAPC-4 prostate cancer in vivo xenografts.

miR-182, of the miR-183 cluster family, is packaged in exosomes and is detected in human exosomes from serum, breast cells and prostate cells.

Members of the microRNA (miR)-183 family are expressed at high levels in the majority of cancer types, including breast and prostate, and are considered 'oncomiRs'. The purpose of the present study was to investigate the role of exosomes in cell-to-cell transfer of the miR-183 family, which includes miRs-96, -182 and -183. Despite highly detectable levels of these three miRs within prostate and breast cells , only miR-182 was detectable in exosomes isolated from cell culture supernatant.

The microRNA-183 cluster: the family that plays together stays together.

The microRNA (miR)183 cluster, which is comprised of miRs-183, -96 and -182, is also a miR family with sequence homology. Despite the strong similarity in the sequences of these miRs, minute differences in their seed sequences result in both overlapping and distinct messenger RNA targets, which are often within the same pathway. These miRs have tightly synchronized expression during development and are required for maturation of sensory organs.

Differential expression and regulation of vitamin D hydroxylases and inflammatory genes in prostate stroma and epithelium by 1,25-dihydroxyvitamin D in men with prostate cancer and an in vitro model.

Previous work on vitamin D in the prostate has focused on the prostatic epithelium, from which prostate cancer arises. Prostatic epithelial cells are surrounded by stroma, which has well-established regulatory control over epithelial proliferation, differentiation, and the inflammatory response. Here we examined the regulation of vitamin D-related genes and inflammatory genes by 1α,25-dihydroxyvitamin D3 (1,25(OH)2D) in laser-capture microdissected prostate tissue from a vitamin D3 clinical trial and in an in vitro model that facilitates stromal-epithelial crosstalk.