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Objectives: Due to specific physiological functions, prostatic tissues and fluids have unique metabolic profiles. In this study, proton nuclear magnetic resonance spectroscopy ((1)H-NMRS) is used to assess potential metabolic markers of prostate cancer (PCa) in human expressed prostatic secretions (EPS)., Methods: Metabolic profiles of EPS from 52 men with PCa and from 26 healthy controls were analyzed using quantitative (1)H-NMRS. The metabolites quantified included citrate, spermine, myo-inositol, lactate, alanine, phosphocholine, glutamine, acetate, and hydroxybutyrate. Logistic regression (LR) was used to model the risk of PCa based on metabolite concentrations while adjusting for age., Results: The average age of the EPS donors with PCa was 58.0+/-7.0 years and 52.2+/-12.1 for the healthy donors. The median Gleason score for the men with PCa was 7 (range 5-9). The LR models indicated that the absolute concentrations of citrate, myo-inositol, and spermine were highly predictive of PCa and inversely related to the risk of PCa. The areas under the receiver operating characteristic curves (AUROC) for citrate, myo-inositol and spermine were 0.89, 0.87, and 0.79, respectively. At 90% sensitivity, these metabolites had specificities of 74%, 51%, and 34%, respectively. The LR analysis indicated that absolute levels of these three metabolites were independent of age., Conclusions: The results indicate that citrate, myo-inositol and spermine are potentially important markers of PCa in human EPS. Further, the absolute concentrations of these metabolites in EPS appear to be independent of age, increasing the potential utility of these markers due to elimination of age as a confounding variable.

Background: Many of the available human prostate cancer (PC) cell lines have lost androgen sensitivity and no longer secrete prostate-specific proteins after serial culturing in cell monolayers. Three-dimensional spheroid cultures have been found to better mimic the in vivo phenotypes of several nonprostatic cell lines., Methods: We analyzed seven PC cell lines to determine if spheroid culturing results in greater sensitivity to androgens and 1alpha,25(OH)(2) vitamin D(3) (1,25(OH)(2) D(3)) with regards to their growth, differentiation, and apoptotic potential., Results: Only PC-3 cells showed greater sensitivity to the growth-inhibitory effects of 1, 25(OH)(2) D(3), while ALVA-31 showed a diminished response. The regulation of prostate-specific antigen and prostate-specific acid phosphatase remained unchanged. However, these studies provided several unique findings not observed in cell monolayers. First, three basic spheroid morphologies were observed with varying degrees of intercellular adhesions. Secondly, the cell lines that formed the tightest spheroids consistently grew at the slowest rates, regardless of their growth rate in monolayers. Lastly, 1,25(OH)(2) D(3) treatment of ALVA-31 and PPC-1 spheroids greatly reduced intercellular adhesions, and rendered ALVA-31 spheroids resistant to apoptotic induction by Fas ligand expressed via a recombinant adenoviral construct., Conclusions: Our results suggest that spheroid cultures of human PC cells may provide unique insights regarding cell adhesion and apoptotic potential that are diminished or absent in monolayer cultures., (Copyright 1999 Wiley-Liss, Inc.)

Background: Apoptosis, or programmed cell death, can be mediated through an endogenous signaling pathway that emanates from a cell surface receptor known as Fas. Although best recognized for its role in the immune system, recent studies have also suggested a role for Fas in mediating apoptosis in the murine prostate. Little is known, however, regarding the role of Fas-signaling in the human prostate, and if this signaling pathway is abrogated in the development of prostate cancer (PC)., Methods: In the current study, seven human PC cell lines were evaluated for their sensitivities to Fas-mediated apoptosis, using both morphologic and flow cytometric methods. Fas expression by each cell line was quantitated by immunofluorescence, and gene expression of three putative inhibitory molecules was analyzed., Results: The differential sensitivities of the cell lines to Fas-mediated apoptosis were found to correlate with the clinical stage of the parental tumors. Specifically, the three most sensitive cell lines were all derived from primary tumors, while the four most resistant cell lines were derived from distant metastases. Immunofluorescent analyses of the PC cell lines revealed that the observed resistance to apoptosis was not due to reduced expression of membrane-bound Fas. Likewise, this resistance did not correlate with increased gene expression of the inhibitory molecules FAP-1, ICE epsilon, and Ich-1S., Conclusions: Our results using established PC cell lines support previous studies with prostatic tissue specimens, and suggest that the normal, differentiated prostatic epithelium, as well as locally invasive PCs, have the potential to undergo Fas-mediated apoptosis. Conversely, these studies suggest that metastatic PCs have a reduced apoptotic potential that is mediated by a novel mechanism.

This paper describes a serum-free defined medium (Gc) that was initially designed to support growth of the human prostatic carcinoma cell line LNCaP. Our studies indicate that this medium formulation is capable of supporting short-term, long-term, and clonal growth of the LNCaP cell line. Component deletion experiments have shown that the three most critical components for LNCaP short-term growth are insulin, triiodothyronine (T3), and fetuin. Additionally, this medium was found to support short-term and clonal growth of three other human prostatic carcinoma cell lines, DU 145, PC-3, and ALVA-31. The availability of such a medium should aid in the distinction of the regulatory factors involved in growth and differentiation of malignant prostatic epithelium.