Villis R. Marshall

The effect of urine, pyrophosphate, citrate, magnesium and glycosaminoglycans on the growth and aggregation of calcium oxalate crystals in vitro

The effects of pyrophosphate, citrate, magnesium, heparin and chondroitin sulphate on the growth and aggregation of calcium oxalate crystals were measured at concentrations likely to be found in 1% urine. The degrees of inhibition of growth and of aggregation caused by these compounds were related to the effects of normal 1% urine on these processes. It was concluded that chondroitin sulphate is responsible for the major portion of the inhibitory effect of urine on crystal aggregation, but that the effect on crystal growth is probably due to the additive or synergistic effects of a number of urinary constituents.

Discovery of circulating microRNAs associated with human prostate cancer using a mouse model of disease

Circulating microRNAs (miRNAs) are emerging as useful non‐invasive markers of disease. The objective of this study was to use a mouse model of prostate cancer as a tool to discover serum miRNAs that could be assessed in a clinical setting. Global miRNA profiling identified 46 miRNAs at significantly altered levels (p ≤ 0.05) in the serum of TRansgenic Adenocarcinoma of Mouse Prostate (TRAMP) mice with advanced prostate cancer compared to healthy controls. A subset of these miRNAs with known human homologues were validated in an independent cohort of mice and then measured in serum from men with metastatic castration‐resistant prostate cancer (mCRPC; n = 25) or healthy men (n = 25). Four miRNAs altered in mice, mmu‐miR‐141, mmu‐miR‐298, mmu‐miR‐346 and mmu‐miR‐375, were also found to be at differential levels in the serum of men with mCRPC. Three of these (hsa‐miR‐141, hsa‐miR‐298 and hsa‐miR‐375) were upregulated in prostate tumors compared with normal prostate tissue, suggesting that they are released into the blood as disease progresses. Moreover, the intra‐tumoral expression of hsa‐miR‐141 and hsa‐miR‐375 were predictors of biochemical relapse after surgery. This study is the first to demonstrate that specific serum miRNAs are common between human prostate cancer and a mouse model of the disease, highlighting the potential of such models for the discovery of novel biomarkers.

Finasteride significantly reduces acute urinary retention and need for surgery in patients with symptomatic benign prostatic hyperplasia

OBJECTIVES A pooled analysis of all available randomized trials with 2-year follow-up data with finasteride and placebo was undertaken to further investigate recent observations that finasteride use may reduce the occurrence of acute urinary retention (AUR) and benign prostatic hyperplasia (BPH)-related surgical intervention. METHODS Occurrences of AUR and surgical intervention were examined by treatment group in a pooled series of 4222 men with moderately symptomatic BPH. RESULTS In total, 81 occurrences of AUR were reported, 24 (1.1%) of 2113 in the finasteride group and 57 (2.7%) of 2109 in the placebo group. The hazard ratio was consistent in all three studies, with a 57% decrease in the hazard rate for occurrence of AUR with finasteride compared with that for placebo present in the pooled data set over the 2-year study period (P < 0.001). Additionally, 227 surgical interventions were recorded over the 2-year study period, 89 (4.2%) of 2113 in the finasteride group and 138 (6.5%) of 2109 in the placebo group. The hazard ratio was consistent across the three studies, with a 34% reduction in the hazard rate for occurrence of surgery with finasteride compared with that for placebo (P < 0.002). Overall, there was 35% reduction in the two BPH-related end points (ie, AUR or surgery). CONCLUSIONS Treatment with finasteride for up to 2 years more than halves the frequency of AUR and reduces surgical intervention by over one third relative to placebo in patients with moderate BPH. This is the first demonstration that long-term medical therapy can reduce clinically significant end points such as AUR or surgery, and these data have important implications for the long-term management of patients with BPH.

Formation of Hyaluronan- and Versican-rich Pericellular Matrix by Prostate Cancer Cells Promotes Cell Motility

Previous studies have demonstrated that high levels of hyaluronan (HA) and the chondroitin sulfate proteoglycan, versican in the peritumoral stroma are associated with metastatic spread of clinical prostate cancer. In vitro integration of HA and versican into a pericellular sheath is a prerequisite for proliferation and migration of vascular smooth muscle cells. In this study, a particle exclusion assay was used to determine whether human prostate cancer cell lines are capable of assembling a pericellular sheath following treatment with versican-containing medium and whether formation of a pericellular sheath modulated cell motility. PC3 and DU145, but not LNCaP cells formed prominent polarized pericellular sheaths following treatment with prostate fibroblast-conditioned medium. The capacity to assemble a pericellular sheath correlated with the ability to express membranous HA receptor, CD44. HA and versican histochemical staining were observed surrounding PC3 and DU145 cells following treatment with prostatic fibroblast-conditioned medium. The dependence on HA for integrity of the pericellular sheath was demonstrated by its removal following treatment with hyaluronidase. Purified versican or conditioned medium from Chinese hamster ovary K1 cells overexpressing versican V1, but not conditioned medium from parental cells, promoted pericellular sheath formation and motility of PC3 cells. Using time lapse microscopy, motile PC3 cells treated with versican but not non-motile cells exhibited a polar pericellular sheath. Polar pericellular sheath was particularly evident at the trailing edge but was excluded from the leading edge of PC3 cells. These studies indicate that prostate cancer cells recruit stromal components to remodel their pericellular environment and promote their motility.

Epidemiologic Survey of Lower Urinary Tract Symptoms in Asia and Australia Using the International Prostate Symptom Score

Background The prevalence of lower urinary tract symptoms was determined by survey as an initial step in estimating the significance of benign prostatic hyperplasia (BPH) in Asia and Australia.

The Estimation of Bladder Volume by Sonocystography

Real-time ultrasonography was used to measure bladder volumes. Volumes were calculated as the product of 3 internal bladder diameters (height, width and depth). The true bladder volume was obtained from the voided volume or by catheterization. There was a good correlation between calculated and true volumes provided a correction factor of 0.6 was applied. It also was found that a simpler method using only 2 diameters and a correction factor of 0.15 was nearly as reliable. The accuracy of this quantitative method was shown to be limited to an average error of plus or minus 25 per cent for bladder volumes between 100 and 500 ml. Smaller volumes could be assessed only qualitatively. False negative readings were common for bladder volumes less than 50 ml.

Global Levels of Specific Histone Modifications and an Epigenetic Gene Signature Predict Prostate Cancer Progression and Development

Background: Epigenetic alterations are common in prostate cancer, yet how these modifications contribute to carcinogenesis is poorly understood. We investigated whether specific histone modifications are prognostic for prostate cancer relapse, and whether the expression of epigenetic genes is altered in prostate tumorigenesis. Methods: Global levels of histone H3 lysine-18 acetylation (H3K18Ac) and histone H3 lysine-4 dimethylation (H3K4diMe) were assessed immunohistochemically in a prostate cancer cohort of 279 cases. Epigenetic gene expression was investigated in silico by analysis of microarray data from 23 primary prostate cancers (8 with biochemical recurrence and 15 without) and 7 metastatic lesions. Results: H3K18Ac and H3K4diMe are independent predictors of relapse-free survival, with high global levels associated with a 1.71-fold (P < 0.0001) and 1.80-fold (P = 0.006) increased risk of tumor recurrence, respectively. High levels of both histone modifications were associated with a 3-fold increased risk of relapse (P < 0.0001). Epigenetic gene expression profiling identified a candidate gene signature (DNMT3A, MBD4, MLL2, MLL3, NSD1, and SRCAP), which significantly discriminated nonmalignant from prostate tumor tissue (P = 0.0063) in an independent cohort. Conclusions: This study has established the importance of histone modifications in predicting prostate cancer relapse and has identified an epigenetic gene signature associated with prostate tumorigenesis. Impact: Our findings suggest that targeting the epigenetic enzymes specifically involved in a particular solid tumor may be a more effective approach. Moreover, testing for aberrant expression of epigenetic genes such as those identified in this study may be beneficial in predicting individual patient response to epigenetic therapies. Cancer Epidemiol Biomarkers Prev; 19(10); 2611–22. ©2010 AACR.

Control of Androgen Receptor Signaling in Prostate Cancer by the Cochaperone Small Glutamine–Rich Tetratricopeptide Repeat Containing Protein α

Although the androgen receptor (AR) is accepted as the major determinant of prostate cancer cell survival throughout disease progression, it is currently unclear how the receptor sustains genomic signaling under conditions of systemic androgen ablation. Here, we show that the evolutionarily conserved Hsp70/Hsp90 cochaperone, small glutamine-rich tetratricopeptide repeat containing protein alpha (alphaSGT), interacts with the hinge region of the human AR in yeast and mammalian cells. Overexpression and RNA interference revealed that alphaSGT acts to (a) promote cytoplasmic compartmentalization of the AR, thereby silencing the receptors basal/ligand-independent transcriptional activity, (b) regulate the sensitivity of receptor signaling by androgens, and (c) limit the capacity of noncanonical ligands to induce AR agonist activity. Immunofluorescence, coactivator, and chromatin immunoprecipitation analyses strongly suggest that these effects of alphaSGT on AR function are mediated by interaction in the cytoplasm and are distinct from the receptors response to classic coregulators. Quantitative immunohistochemical analysis of alphaSGT and AR levels in a cohort of 32 primary and 64 metastatic human prostate cancers revealed dysregulation in the level of both proteins during disease progression. The significantly higher AR/alphaSGT ratio in metastatic samples is consistent with the sensitization of prostate tumor cells to androgen signaling with disease progression, particularly in a low-hormone environment. These findings implicate alphaSGT as a molecular rheostat of in vivo signaling competence by the AR, and provide new insight into the determinants of androgen sensitivity during prostate cancer progression.

Effects of chondroitin sulphate, human serum albumin and Tamm-Horsfall mucoprotein on calcium oxalate crystallization in undiluted human urine

SummaryThe effects of physiological concentrations of chondroitin sulphate, human serum albumin and Tamm-Horsfall mucoprotein on the crystallization of calcium oxalate in undiluted, ultrafiltered human urine were investigated using particle size analysis and scanning electron microscopy. Neither the amount of oxalate required to induce detectable calcium oxalate crystal nucleation nor crystal morphology was affected by the presence of any of these macromolecules. Chondroitin sulphate had no effect on the amount of crystalline material deposited or on the size of the particles precipitated in response to a standard oxalate load. Human serum albumin slightly reduced the size of the crystal aggregates and caused a small increase in the amount of crystal matter precipitated. By contrast, Tamm-Horsfall mucoprotein significantly inhibited crystal aggregation and markedly increased the volume of matter deposited, although this could not be attributed to a promotion of solute precipitation. It was concluded that chondroitin sulphate, human serum albumin and Tamm-Horsfall mucoprotein cannot account for the inhibitory effects of macromolecules with a relative mass greater than 10 kDa in spun and filtered urine. Nonetheless, Tamm-Horsfall mucoprotein is likely to inhibit crystal aggregation in whole urine in vivo and may therefore be instrumental in preventing calcium oxalate stone formation.

Fine Needle Aspiration Cytology in the Diagnosis of Solid Renal and Adrenal Masses

In the eight-year period 1977-1984, 83 renal and adrenal mass lesions which were not clearly simple cysts by ultrasonographic examination (US) were investigated by percutaneous fine needle aspiration (FNA) biopsy. Initially, biopsy was often guided by fluoroscopy, later US was by far the most commonly used modality. There were 77 renal and 6 adrenal masses; 69 lesions were malignant and 14 were benign. A positive cytological diagnosis of malignancy was given in 62 cases, a diagnostic sensitivity of 90%. One false positive diagnosis occurred, an angiomyolipoma was misinterpreted as a low grade renal cell tumour. One significant complication was recorded, post biopsy haemorrhage into a large, extensively necrotic renal adenocarcinoma causing severe pain. The place of FNA in the preoperative investigation of solid renal tumours is discussed on the basis of this experience and results reported in the literature.