Lili Ou

Small interference RNA-mediated silencing of prostate stem cell antigen attenuates growth, reduces migration and invasion of human prostate cancer PC-3M cells

OBJECTIVES Prostate stem cell antigen (PSCA), a glycosylphosphatidylinositol (GPI)-anchored cell surface glycoprotein, is highly expressed in both local and metastatic prostate cancer (CaP). Elevated PSCA expression has been shown to correlate with malignant phenotype and clinical progression. The purpose of the current study is to investigate the therapeutic potential of small interference RNA (siRNA) targeting PSCA on human CaP cells. MATERIALS AND METHODS A set of two siRNAs directed different regions of human PSCA (siRNA-PSCA) were designed and transfected into a human CaP PC-3M cell line. The silencing effect was screened by RT-PCR and Western blotting. The biological effects of siRNA-PSCA on PC-3M cells were investigated by examining the cell proliferation through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, cell cycle distribution through flow cytometry, and migration and invasion potencies through transwell invasion assay upon the PSCA silencing. RESULTS PC-3M cells had positive PSCA expression on immunocytochemical assay. PSCA expression was depleted at 48 hours after transfection with siRNA-PSCA. Silencing of PSCA significantly suppressed cell proliferation. Cell cycle assay showed that the anti-proliferation effect of siRNA-PSCA was mediated by arresting cells in the G0/G1 phase rather than apoptosis. Furthermore, PSCA knockdown resulted in a marked decrease of cell migration and invasion capabilities in PC-3M cells. CONCLUSIONS The present study provides the first evidence that silencing PSCA using siRNA can inhibit the proliferation and invasiveness properties of human CaP cells, which may provide a promising therapeutic strategy for CaP and open a novel avenue toward the investigation of the role of PSCA overexpression in cancers.

Peripheral blood reverse transcription PCR assay for prostate stem cell antigen correlates with androgen-independent progression in advanced prostate cancer

Recent studies show that prostate stem cell antigen (PSCA) mRNA positivity in peripheral blood correlates with disease progression in prostate cancer (PCa). Our study is to evaluate the association between peripheral blood PSCA status and androgen‐independent progression (AIP) in a cohort of patients with advanced PCa under androgen deprivation therapy (ADT). PSCA mRNA was measured by reverse transcriptase polymerase chain reaction (RT‐PCR) assay in peripheral blood samples from 116 patients with locally advanced or metastatic PCa who were treated with primary ADT and from 40 healthy controls. The Kaplan–Meier and the Cox proportional hazards methods were used to assess potential predictors of AIP. Pretreatment RT‐PCR‐PSCA was positive in 37 (31.9%) of 116 patients. All healthy volunteers were negative for PSCA mRNA. Although seven (14.9%) of 47 patients with Gleason score ≤7 were PSCA positive, 30 (43.5%) of 69 patients with Gleason score >7 were PSCA positive (p = 0.016). PSCA mRNA was detected in 28 (58.3%) of 48 patients with metastatic PCa, compared to nine (13.2%) of 68 patients with locally advanced disease (p = 0.012). AIP developed in 59 (50.9%) patients during a median follow‐up period of 35.4 months (range: 4–78 months). Patients with PSCA negativity experienced significantly longer remissions compared to those with PSCA positivity (log‐rank test: p < 0.001). Multivariate Cox regression analysis further demonstrated that PSCA positivity had a significantly increased risk of AIP (HR = 4.303, 95% CI: 3.761–7.482, p < 0.001). Pretreatment RT‐PCR PSCA positivity in peripheral blood independently signals the presence of AIP in patients with advanced PCa treated with ADT.

Impact of Plasmakinetic Enucleation of the Prostate (PKEP) on Sexual Function: Results of a Prospective Trial

INTRODUCTION Recent data have shown that plasmakinetic enucleation of the prostate (PKEP) is a novel and effective procedure for symptomatic benign prostatic hyperplasia (BPH); however, data on patient sexual function after PKEP remain scarce. AIMS This study aims to evaluate the impact of PKEP on sexual function in men with lower urinary tract symptoms because of BPH. METHODS One hundred eighty-six consecutive patients who underwent the PKEP procedure were prospectively enrolled in this study. The International Index of Erectile Function (IIEF-15) and the International Prostate Symptom Score with quality of life scores were completed and compared preoperatively and at 1, 3, 6, and 12 months postoperatively. At each follow-up visit, maximum urinary flow rates, transrectal ultrasound-assessed prostate volume, postvoid residual urine volume, and serum prostate-specific antigen level were also measured and compared with the baseline. MAIN OUTCOME MEASURES The IIEF global score and its five domains scores were evaluated for each patient, and the Friedman test or chi-square test was used to identify changes from the baseline. RESULTS There was a slight and nonsignificant increase in the IIEF global score and four of its five domains scores (i.e., erectile function, intercourse satisfaction, sexual desire, and overall satisfaction) at each postoperative assessment (P > 0.05 for all). However, a statistically significant reduction was observed in the orgasmic function domain score of IIEF at 3 months (P = 0.016), 6 months (P < 0.001), and 12 months (P < 0.001), respectively, along with the corresponding retrograde ejaculation rates of 48.7%, 49.4%, and 48.8%. CONCLUSIONS PKEP has no negative influence on the quality of erections measured by the self-administered IIEF questionnaire, but it significantly lowers the orgasmic function domain score, reflecting probably postoperative retrograde ejaculation. These findings are important in preoperative counseling of the patients undergoing PKEP for symptomatic BPH.

Preoperative serum levels of early prostate cancer antigen (EPCA) predict prostate cancer progression in patients undergoing radical prostatectomy.

Early prostate cancer antigen (EPCA) has been shown a prostate cancer (PCa)‐associated nuclear matrix protein, however, its serum status and prognostic power in patients with PCa are unknown. The goals of this study are to measure preoperative serum EPCA levels in a cohort of PCa patients who were treated with radical prostatectomy (RP), and to investigate whether serum EPCA levels would independently predict cancer prognosis after the surgery.

Collection and storage of urine specimens for measurement of urolithiasis risk factors.

OBJECTIVE To evaluate how different methods for storage and preservation of urine samples affected the outcome of analysis of risk factors for stone formation. METHODS Spot urine samples were collected from 21 healthy volunteers. Each fresh urine sample was divided into ten 10-mL aliquots: 2 without preservative, 2 with thymol, 2 with toluene, 2 with hydrochloric acid (HCl), and 2 with sodium azide. One sample of each pair was stored at 4 °C and the other at room temperature. The concentrations of calcium, magnesium, sodium, phosphate, urate, oxalate, citrate, and pH in each urine sample were analyzed immediately after collection (0 hour) and after 24 and 48 hours. RESULTS There were no significant differences in calcium, oxalate, magnesium, phosphate, sodium, urate or pH (without acidification) between samples with different preservation methods (P >.05). Urinary citrate, however, was significantly lower in the urine collected with HCl than when other preservatives were used, both at room temperature and at 4 °C. Urine pH was significantly higher after 48 hours than after 24 hours, whether the samples were stored at room temperature or at 4 °C. CONCLUSION Antibacterial preservatives (eg, thymol or toluene) can be recommended as preservatives for 24-hour urine collections. Ideally, the samples should be stored at 4 °C. When HCl is used as a preservative, it seems essential to neutralize the samples before analysis. This is particularly obvious with the chromatographic method used for analysis of citrate that was used in this study.

Serum early prostate cancer antigen (EPCA) level and its association with disease progression in prostate cancer in a Chinese population.

Background Early prostate cancer antigen (EPCA) has been shown a prostate cancer (PCa)-associated nuclear matrix protein, however, its serum status and prognostic power in PCa are unknown. The goals of this study are to measure serum EPCA levels in a cohort of patients with PCa prior to the treatment, and to evaluate the clinical value of serum EPCA. Methods Pretreatment serum EPCA levels were determined with an ELISA in 77 patients with clinically localized PCa who underwent radical prostatectomy and 51 patients with locally advanced or metastatic disease who received primary androgen deprivation therapy, and were correlated with clinicopathological variables and disease progression. Serum EPCA levels were also examined in 40 healthy controls. Results Pretreatment mean serum EPCA levels were significantly higher in PCa patients than in controls (16.84±7.60 ng/ml vs. 4.12±2.05 ng/ml, P<0.001). Patients with locally advanced and metastatic PCa had significantly higher serum EPCA level than those with clinically localized PCa (22.93±5.28 ng/ml and 29.41±8.47 ng/ml vs. 15.17±6.03 ng/ml, P = 0.014 and P<0.001, respectively). Significantly elevated EPCA level was also found in metastatic PCa compared with locally advanced disease (P<0.001). Increased serum EPCA levels were significantly and positively correlated with Gleason score and clinical stage, but not with PSA levels and age. On multivariate analysis, pretreatment serum EPCA level held the most significantly predictive value for the biochemical recurrence and androgen-independent progression among pretreatment variables (HR = 4.860, P<0.001 and HR = 5.418, P<0.001, respectively). Conclusions Serum EPCA level is markedly elevated in PCa. Pretreatment serum EPCA level correlates significantly with the poor prognosis, showing prediction potential for PCa progression.

Serum estradiol and testosterone levels in kidney stones disease with and without calcium oxalate components in naturally postmenopausal women.

Objective Epidemiological data reveal that the overall risk for kidney stones disease is lower for women compared to age-matched men. However, the beneficial effect for the female sex is lost upon menopause, a time corresponding to the onset of fall in estrogen levels. The aim of this study was to describe the serum estradiol (E2) and testosterone (T) characteristics of naturally postmenopausal women with kidney stones. Methods 113 naturally postmenopausal women with newly diagnosed kidney stones (aged 57.4±4.98 years) and 84 age frequency matched stone-free controls (56.9±4.56 years) were validly recruited in the case-control study. The odds ratios (ORs) for the associations between sex hormones and kidney stones were estimated with logistic regression models, adjusting for demographic data and medical history. Patients were also stratified analyzed according to stone components (calcium oxalate stones [COS]; non-calcium oxalate stones [NCOS]). Results Serum E2 (21.1 vs. 31.1 pg/ml) was significantly lower in kidney stones patients compared to controls. Post-hoc analysis demonstrated that this effect was driven by COS patients (p<0.001). According to tertiles of the E2 levels, a significant higher frequency of COS was seen in the lowest E2 group (p <0.001). Multiple logistic regression analysis identified E2 level as a strong factor that was independently associated with the risk for COS (per 1 SD increase, OR=0.951, 95% confidence interval [CI] = 0.919-0.985; highest: lowest tertile, OR=0.214, 95%CI = 0.069-0.665). However, serum T levels did not significantly differ among the groups. Conclusions Naturally postmenopausal women with higher remaining estradiol levels appear less likely to suffer from kidney calcium oxalate stones. However, no correlation was found between serum T level and kidney stones. These findings support the hypothesis that higher postmenopausal endogenous estrogens may protect against kidney stones with ageing.

Interconversion of stone composition profiles from two recurrent stone episodes in stone formers

Abstract Background: The aim of the study was to investigate the interconversion of the stone chemical composition of two recurrent stone episodes in stone formers. Methods: The data of 1098 stones analyses from 549 patients with a history of two renal stone episodes were selected and reviewed. The stone composition between the two recurrent episodes of stones was compared. Results: The percent occurrences of stones caused by infection, known as infection stones, in new episodes of stones significantly increased by 7% and uric acid stones increased by 3.8% while the calcium oxalate stones decreased by 13.1% (each p<0.05). The mean recurrent interval of new episodes of stones was 34.2 months. Infection stones had a significant shorter interval time compared to calcium oxalate stones (p<0.001). On a patient-by-patient investigation, 32.9% of patients underwent conversions of stone compositions, with 31.9% and 34.1% in men and female, respectively (p=0.590). The mutual conversion of infection stones to calcium oxalate stones was most common. The 61.1% of patients with uric acid recurrent stones were composed of calcium oxalate in the previous episode of stones, and 5% and 51.7% of patients with infection stones developed stones of uric acid or calcium oxalate in the new episode, respectively. Conclusions: Alterations of stone components during follow-up were found in as high as 32.9% of patients with no gender difference. The impetus of these shifts is not readily apparent. Accurate and repeated stone analyses throughout the course of recurrent stone disease are highly warranted, which may be useful to prevent recurrence of composition-specific stones.

Reference intervals for stone risk factors in 24-h urine among healthy adults of the Han population in China

Abstract Background: The aim of the study was to establish reference intervals for 24-h urinary stone risk factors in the healthy Chinese Han population. Methods: From May 2013 to July 2014, we collected and analyzed 24-h urine samples from healthy adult Han population during a cross-sectional study across China. The protocol for analysis of 24-h urine included volume, pH, oxalate, citrate, sodium, potassium, chloride, calcium, phosphorous, creatinine, urate, magnesium, the ion activity products of calcium oxalate (AP(CaOx) indexs) and calcium phosphate (AP(CaP) indexs). We calculated the reference intervals according to the Clinical and Laboratory Standards Institute (CLSI) 2008 guidelines and compared them with those recorded in other studies. Results: A total of 132 male and 123 female healthy subjects with a mean (SD, range) age of 52.4 (15.2, 19–89) years were eligible in the final analysis. Men had higher 24-h excretion of creatinine, calcium, urate and phosphorus and lower levels of citrate, magnesium, chloride, sodium and potassium than women. AP(CaOx) indexs and AP(CaP) indexs were significantly higher among men than women. When urinary findings were compared with the reference intervals, most of our data showed a high abnormality rate, especially for creatinine, calcium, citrate, magnesium, chloride, sodium and potassium. Conclusions: The present study revealed the normal metabolic status for stone risk factors of the Chinese Han population. It is therefore necessary for each country or region to define their own reference intervals for comparison of stone risk factors between patients and healthy subjects.