Manganese antagonizes iron blocking mitochondrial aconitase expression in human prostate carcinoma cells

Aim： To investigate the possible role of manganese in the regulation of mitochondrial aconitase （mACON） activity human prostate carcinoma cell line PC-3 cells. Methods： The mACON enzymatic activities of human prostate carcinoma cell line PC-3 cells were determined using a reduced nicotinamide adenine dinucleotide-coupled assay. Immunoblot and transient gene expression assays were used to study gene expression of the mACON. The putative response element for gene expression was identified using reporter assays with site-directed mutagenesis and electrophoretic mobility-shift assays. Results： In vitro study revealed that manganese chloride （MnCI2） treatment for 16 h inhibited the enzymatic activity of mACON, which induced the inhibition of citrate utility and cell proliferation of PC- 3 cells. Although results from transient gene expression assays showed that MnCI2 treatment upregulated gene translation by approximately 5-fold through the iron response element pathway, immunoblot and reporter assays showed that MnCl2 treatments inhibited protein and gene expression of mACON. This effect was reversed by cotreatment with ferric ammonium citrate. Additional reporter assays with site-directed mutagenesis and electrophoretic mobility-shift assays suggested that a putative metal response element in the promoter of the mACON gene was involved in the regulation of MnCh on the gene expression of mACON. Conclusion： These findings suggest that manganese acts as an antagonist of iron, disrupting the enzymatic activity and gene expression of mACON and citrate metabolism in the prostate.

Detection of androgen receptor (AR) and AR-V7 in small cell prostate carcinoma: Diagnostic and therapeutic implications

Objective:Small cell prostate carcinoma(SCPC)is a rare and highly malignant subtype of prostate cancer.SCPC frequently lacks androgen receptor(AR)and prostate-specific antigen(PSA)expression,and often responds poorly to androgen deprivation therapy(ADT).AR splice variant-7(AR-V7)is a truncated AR protein implicated in resistance to AR-targeting therapies.AR-V7 expression in castration-resistant prostate cancers has been evaluated extensively,and blood-based detection of AR-V7 has been associated with lack of response to abiraterone and enzalutamide.However,whether AR-V7 is expressed in SCPC is not known.Methods:Using validated antibodies,we performed immunohistochemistry(IHC)assay for the full-length AR(AR-FL)and(AR-V7)on post-ADT surgical SCPC specimens.Results:Seventy-five percent(9/12)of the specimens showed positive staining for the AR-FL with various intensities.Thirty-three percent(4/12)of the specimens showed positive staining for AR-V7.Among the specimens with positive AR-V7 staining,two samples displayed very weak staining,one sample showed weak-to-moderate staining,and one sample showed strong staining.All positive specimens displayed a heterogeneous pattern of AR-FL/AR-V7 staining.All specimens positive for AR-V7 were also positive for AR-FL.Conclusion:The study findings support the existence of measurable AR-FL and AR-V7 proteins in SCPC specimens.The results also have implications in detection of AR-V7 in specimens obtained through systemic sampling approaches such as circulating tumor cells.A positive AR-V7 finding by blood-based tests is not impossible in patients with SCPC who often demonstrate low PSA values.

The Inhibitory Effects of an Antisense u-PAR Vector on Invasion of Highly Invasive Human Prostate Carcinoma PC-3M Cell Subclones

To observe the inhibitory effects of an antisense u-PAR vector on invasion of highly invasive PC-3M cell subclones, the effects of the antisense u-PAR on activity of MMP-9 in those highly invasive cell subclones were detected by a quantitative RT-PCR and zymography. The monolayer invasion assay and colony formation assay in soft agar were used. And tumorigenesis rate and invasions by the cell subclones with or without the antisense u-PAR were observed in nude mice. It was found that in vitro growth of highly invasive PC-3M cell subclones transfected with the antisense u-PAR was declined, and the ability of anchorage-independent growth of those cell subclones was found decreased sharply, with the inhibiting rate becoming 79%and 60% , respectively. Although the anti-sense u-PAR didn't change MMP-9 gene transcription, they could inhibit the activation of MMP-9 of highly invasive PC-3M cell subclones. Moreover, the tumorigenesis rate of the cell subclones with the antisense u-PAR decreased and the growth of a neoplasm also slowed down. The t tests showed the difference between experimental and control groups was statistically significant (P<0.01). The anti-sense u-PAR vector could not only inhibit the invasion ability of highly invasive PC-3M cell subclones in vitro but also restrain the growth of those cell subclones in vivo.

Misdiagnosis of Left Supraclavicular Lymph Node Metastasis of Prostate Carcinoma: One Case Report and Literatures Review

IntroductionChina is a country with a low morbidity of prostate carcinoma. The incidence of prostate carcinoma in China is 1.6/100,000, which is much lower than the rate in the United States, i.e., 119.9/100,000. Due to changes of lifestyle and improved measurement of serum prostate specific antigen （PSA） over the past decades, the incidence of prostate carcinoma in China also showed a yearly increase. However, the misdiagnosis and mistreatment of this disease commonly occur. The aim of this study is to report the case of a patient with prostate carcinoma presenting asymptomatic but with left supraclavicular lymphadenopathy, and analyze the reasons of misdiagnosis and mistreatment.

Effect of Intermittent Androgen Blockade on the Quality of Life of Patients with Advanced Prostate Carcinoma

OBJECTIVE To investigate the effect of intermittent androgen blockade （IAB） on the quality of life （QOL） of patients with advanced prostatic carcinoma （APC）. METHODS Investigations on the QOL of 51 APC patients receiving lAB treatment, totaling 3 times, i.e. 6 months before and after, and 12 months after treatment, were perform using the EORTC QLQ-C30 measuring scale and QLQ-PR25 scale. RESULTS Although lAB became an economic burden for the families, it was lessened during the intermission （P〈0.05）. The overall health status significantly improved 6 months after lAB treatment （P〈0.01）, especially during the intermission （P〈0.05）, with a total or local easement of pain （P〈0.01） and an improvement of urinary function （P〈0.01）. Although there was impairment, to various degrees, in many functions of the patients on the 6th month of treatment, such as the physical function （P〈0.05）, role function （P〈0.05）, the emotional （P〈0.01） and the social functions （P〈0.01）, with an enhancement of fatigue （P〈0.01）, these functions gradually recovered by the 12th month as the intermission started. Treatment-related symptoms such as flushing and mammary swelling significantly emerged on the 6th treatment month （P〈0.01）, and lessened on the 12th （P〈0.01）. During the treatment period, there was an notable drop in sexual interest （P〈0.01）, with a deprivation of sex life, but revived to various degrees during the intermission （P〈0.01）. CONCLUSION Although lAB treatment of APC patients did impair the physiologic and psychologic status of patients to varying degrees, these were improved and restored during the intermission.

Preliminary Study of Selenium (Se) Toxicity in Human Prostate Carcinoma (PC3) Cells with the Overexpression of Selenocysteine Synthase (SecS) Gene

Selenium (Se) is a trace element required for normal body function. Its supplementation of human diet at standard optimum amount prevents oxidative damages in cells and could be a viable method in the prevention of diseases related to DNA damage, including cancer, neurodegenerative diseases and aging. While Se anticancer properties have been linked to its ability to remove excess Reactive Oxygen Species (ROS) in cells, the underlying molecular mechanism remains unknown. Recent studies have shown that the removal of ROS alone cannot account for Se anticancer properties. To really comprehend the molecular basis of Se anticancer properties, current researches now focus on the metabolism of Se in the cell, especially Se-containing amino acids. Selenocysteine (Sec) is a novel amino acid and one of the selenium-containing compounds in the cell. It is essential in the maintenance of the integrity of its parent proteins, some of which include enzymes such as Glutathione Peroxidases (GPXs) and Thioredoxin Reductases (TrXs). We propose in this study that the overproduction of Sec via the overexpression of Selenocysteine synthase (SecS) gene and Se supplementation induced cell death in Prostate Carcinoma (PC-3) cells. Although the mechanism underlying the cell death induction is unknown, we propose it could be due to the random incorporation of Sec into proteins at high concentration, causing premature protein degradation and cell death. The outcome of this study showed that increasing the concentration of intracellular Se-containing amino acids may provide important clinical implications for the treatment of cancer.

Manganese antagonizes iron blocking mitochondrial aconitase expression in human prostate carcinoma cells

Aim:To investigate the possible role of manganese in the regulation of mitochondrial aconitase(mACON)activity human prostate carcinoma cell line PC-3 cells.Methods:The mACON enzymatic activities of human prostate carcinoma cell line PC-3 cells were determined using a reduced nicotinamide adenine dmucleotide-coupled assay. Immunoblot and transient gene expression assays were used to study gene expression of the mACON.The putative response element for gene expression was identified using reporter assays with site-directed mutagenesis and electro- phoretic mobility-shift assays.Results:In vitro study revealed that manganese chloride(MnCl2)treatment for 16h inhibited the enzymatic activity of mACON,which induced the inhibition of citrate utility and cell proliferation of PC- 3 cells.Although results from transient gene expression assays showed that MnCl_2,treatment upregulated gene translation by approximately 5-fold through the iron response element pathway,immunoblot and reporter assays showed that MnCl_2 treatments inhibited protein and gene expression of mACON.This effect was reversed by co- treatment with fenic ammonium citrate.Additional reporter assays with site-directed mutagenesis and electrophoretic mobility-shift assays suggested that a putative metal response element in the promoter of the mACON gene was involved in the regulation of MnCl_2 on the gene expression of mACON.Conclusion:These findings suggest that manganese acts as an antagonist of iron,disrupting the enzymatic activity and gene expression of mACON and citrate metabolism in the prostate.

Mass screening of 12027 elderly men for prostate carcinoma by measuring serum prostate specific antigen

Background The incidence of prostate carcinoma (Pca) has been increasing in China. We detected Pca in elderly men in Changchun,north China and the significance of prostate specific antigen (PSA) in mass screening and clinical staging of Pca. Methods Serum PSA from 12 027 men over 50 years old from Changchun was analyzed. In case of serum PSA greater than 4.0 ng/ml,the patient was suspected of potentially suffering from Pca,and transrectal six-point puncture prostate biopsies were performed under ultrasound guidance. Pathological examinations were performed on the biopsy tissue,and ABCD and TNM clinical stagings were used in accordance with international standards. Correlations between serum PSA level and clinical stage were analyzed. Results PSA was greater than 4.0 ng/ml in 813 patients (6.8% of the 12 027 men). Transrectal six-point prostate puncture biopsies guided by ultrasound were performed in 273 patients (33.6% of the 813 patients who were tested positive in the initial mass screening). Of these 273 patients,69 cases of Pca (25.3% of 273) were confirmed by biopsy in the second screening,with an overall detection rate for Pca of 0.57% (69/12 027). The total number of patients in stages A,B,T1,or T2 was 57.9%,and over 20% of them suffered from late stage Pca with lymph node and bone metastasis. An obvious positive correlation was observed between ABCD staging,TNM staging,and serum PSA level. Conclusions Serum PSA level is not only the golden standard for mass screening of Pca,but also the predictor for clinical stage of Pca. PSA testing revealed asymptomatic Pca cases in early,middle,and later stages in the elderly,suggesting that mass screening is of paramount importance.

Intraductal carcinoma of prostate(IDC-P): from obscure to significant

The concept of intraductal carcinoma of prostate （IDC-P） has evolved over the years and its clinieopathologic significance has come to be more clearly appreciated. In contrast to morphologically malignant intraductal lesions that represent earlier stages of the malignant process in other anatomic sites such as the breast, IDC-P has now been generally recognized as a prognostically unfavorable manifestation of later stage spreading of its invasive counterpart. We here briefly review the evolution of the IDC-P concept, the histological diagnostic criteria and differential diagnosis, the clinical significance, as well as recent molecular data of IDC-P.

Management about intravesical histological transformation of prostatic mucinous carcinoma after radical prostatectomy:A case report

BACKGROUND Prostatic mucinous carcinoma(MC)and prostatic signet ring cell carcinoma are two variants of prostate cancer.MC has a higher overall survival time among all variants,while signet ring cell carcinoma is associated with lower survival time relative to other carcinomas.Only a small proportion of prostatic MC may contain signet ring cells.Over the last several decades there were only 12 patients that were documented in two studies.CASE SUMMARY We report on a 64-year-old man who was diagnosed with prostatic MC after he received a robotic-assisted laparoscopic radical prostatectomy in the West China Hospital.After robotic-assisted laparoscopic radical prostatectomy,the patient underwent three successive transurethral resections of bladder tumors.Pathological examination of the first transurethral resection of bladder tumors specimen indicated that the neoplasm was prostatic MC that had metastasized to the urinary bladder.The subsequent two transurethral resections of bladder tumors indicated the presence of prostatic mucinous carcinoma with signet ring cells.CONCLUSION This case report aimed to share the management experience,raise awareness,and highlight the importance of multidisciplinary cooperation of prostatic mucinous carcinoma with signet ring cells.

Primary signet ring cell carcinoma of prostate (report of 2 cases)

Objective To study the clinical features of primary signet ring cell carcinoma of prostate. Methods 2 cases of primary signet ring cell carcinoma of the prostate were studied and reviewed. Results The age of the 2 patients was 64 and 73. The clinical symptoms were dysuria, vesical irritability and perineum discomfort. Histologically, signet ring cell carcinoma was composed of round cells with abundant clear cytoplasm and crescent-shaped nuclei on one side. Mitosis were frequently observed. Immunohistochemical testing showed the cancer cell was positive for prostate specific antigen (PSA.), prostate acid phosphatase ( PAP ), AR, cytokeratin and negative for caicinoernbryonic antigen (CEA), alcian blue/ periodic arid-schiff (AB/PAS). One case (stage D) died 6 months after bilateral orchiectomy and flutamide therapy because of wide-spead metastasis; the other (stage B2) has been surviving 25 months after radical prostatectomy, bilateral orchiectomy, endocrine therapy and local irradiation ministration.

Diagnosis and treatment of small cell carcinoma of prostate and a review of literature

Objective To investigate histological features, clinical presentation,treatment and prognosis of small cell carcinoma of prostate. Methods Clinical,pathological and follow-up data of two cases of small cell carcinoma of prostate were respectively analyzed,and trlated literature was reviewed. Results Two cases of small

Diagnostic strategies and the incidence of prostate cancer： reasons for the low reported incidence of prostate cancer in China

We have analysed the reasons for the low reported incidence of prostate cancer in China and argue for early diagnosis and treatment of this disease. According to the 2002 database of the International Agency for Research on Cancer （IARC）, the age-standardized incidence of prostate cancer in China is 1.6/105 person years （PY）, with a mortality rate of 1.0/105 PY and mortality-to-incidence rate ratio （MR/IR） = 0.63. The MR/IR ratio of prostate cancer in China was found to be higher than the average in Asia （MR/IR = 0.57） and much higher than that in North America （MR/IR = 0.13）. These data indicate that in China most prostate cancers were in the advanced stages at the time of diagnosis, and that patients had a short survival time thereafter. In 2004, Stamey et al. reported a retrospective American study of prostate cancer for the years 1983-2003. It was shown that most cases of prostate cancer detected by prostate-specific antigen （PSA） screening were in the advanced stage at the start of this 20-year period. These early follow-up data are quite similar to the results obtained from mass PSA screening of elderly men in Changchun, China. However, after the American programmes for early diagnosis and treatment of prostate cancer were accepted, tumours were diagnosed at earlier stages. On the basis of these findings, mass screening should be performed in the whole of China using serum PSA to facilitate early diagnosis and treatment of prostate cancer.

miR-21, miR-221 and miR-222 expression and prostate cancer recurrence among obese and non-obese cases

Recent evidence shows that certain microRNAs （miRNAs） play a role in both obesity and prostate cancer recurrence, but the association between the expression of these miRNAs and obesity in prostate cancer recurrence is unknown. In this study, we examined the effect of the interaction between obesity and miR-21, miR-221 or miR-222 expression on prostate cancer recurrence among 28 recurrent and 37 non-recurrent prostate cancer cases, miRNA expression was determined using quantitative real-time polymerase chain reaction. Cox proportional hazard models adjusting for age at diagnosis, clinical stage and Gleason score were used to estimate hazard ratios （HR） and 95% confidence intervals （95% CI） for recurrence free survival. A significantly （P=0.014） higher proportion of recurrent cases （78,6%） than non-recurrent cases （48.6%） had a low expression of miR-21 and the difference was more prominent in obese than non-obese patients. Multivariate analysis showed that the expression of miR-21 was an independent risk factor for recurrence in obese （HR=6.15, 95% CI= 1.04-36.48, P=-0.045）, but not in non-obese （HR= 1.28, 95% C1=0.30-5.49, P=0.74） cases. A significant association with recurrence was not observed for the expression of miR-221 and miR-222. In summary, our findings show that miR-21 is associated with prostate cancer recurrence after radical prostatectomy and suggest that the differential expression of miR-21 is more prominent in obese than in non-obese cases. Future larger studies are warranted to confirm these initial findings and to elucidate the mechanisms involved.

Abrogation of heat-shock protein (HSP)70 expression induced cell growth inhibition and apoptosis in human androgen-independent prostate cancer cell line PC-3m

Aim: To investigate the effect of abrogating heat shock protein (HSP) 70 expression by antisense HSP70 oligonucleotides treatment on human androgen-independent prostate cancer cell line PC-3m growth. Methods: PC-3m cells were treated with 0-16 μmol/L antisense HSP70 oligomers for 0-100 hr. Cell growth inhibition was analyzed using a trypan blue dye exclusion test. Apoptotic cells were detected and confirmed by flow cytometric analysis and DNA fragmentation analysis. The protein expression of HSP70 and bcl-2 affected by antisense HSP70 oligomers were determined using Western blot. Results: Antisense HSP70 oligomer induced apoptosis and then inhibited proliferation of PC-3m cells in a dose- and time-dependent manner. Ladder-like patterns of DNA fragments were observed in PC-3m cells treated with 10 μmol/L antisense HSP70 oligomer for 48 hr or 8 μmol/L for 72 hr on agarose gel electrophoresis. Antisense HSP70 oligomer pretreatment enhanced the subsequent induction of apoptosis by heat shock in PC-3m cells. In addition, undetectable HSP70 expression was observed at a concentration of 10 μmol/L antisense HSP70 oligomer treatment for 48 hr or 8 μmol/L for 72 hr in Western blot, which was paralleled by decreased expression levels of anti-apoptotic protein bcl-2. Conclusion: HSP70 antisense oligomer treatment abrogates the expression of HSP70, which may disrupt HSP70-bcl-2-interactions and further down-regulate bcl-2 expression, in turn inducing apoptosis and inhibiting cell growth in PC-3m cells.

Cancer/testis antigens： novel tools for discerning aggressive and non-aggressive prostate cancer

The introduction of serum prostate-specific antigen （PSA） in the 1980s has dramatically altered and benefited the initial diagnosis of prostate cancer. However, the widespread use of PSA testing has resulted in overdetection and overtreatment of potentially indolent disease. Thus, a clinical dilemma today in the management of prostate cancer is to discern men with aggressive disease who need definitive treatment from men whose disease are not lethal. Although several serum and tissue biomarkers have been evaluated during the past decade, improved markers are still needed to enhance the accuracy, with which patients at risk can be discerned and treated more aggressively. The cancer/testis antigens （CTAs） are a group of proteins that are restricted to the testis in the normal adult, but are aberrantly expressed in several types of cancers. Because of their restricted expression pattern, the CTAs represent attractive biomarker candidates for cancer diagnosis/prognosis. Furthermore, several studies to date have reported the differential expression of CTAs in prostate cancer. Here, we review recent developments that demonstrate the potential of the CTAs as biomarkers to discern the a^ressive Dhenotvoe of orostate cancer.

The pathology of unusual subtypes of prostate cancer

There are some current literatures describing the morphologic change of prostate carcinoma variants. Some subtypes do not respond to hormone deprivation therapy, for example adenosquamous and squamous cell carcinoma （SQCC）, basaloid and adenoid cystic carcinoma （ACC）, small cell carcinoma （SmCC）, sarcomatoid carcinoma, urothelial carcinoma; some are defined in special Gleason grade, some develop different prognosis. So, it is very important to identify these rare subtypes to avoid misdiagnosis. In this review, we aim to describe the typical clinicopathological features of the rare variants of prostate cancer, including prostate acinar adenocarcinoma morphologic variants.

Neoadjuvant hormonal deprivation for patients undergoing radical prostatectomy

The purpose of this study is to evaluate the therapeutic effect of radical prostatectomy combined with preoperative neoadjuvant hormonal ablation therapy for prostate cancer （PCa）. In this study, a total of 31 patients with local PCa underwent radical prostatectomy; of these, 12 patients underwent preoperative hormonal deprivation with a combination of goserelin and flutamide for a period of 5.6 months. Data regarding clinical characteristics were compared between the neoadjuvant therapy and radical prostatectomy groups. A total of 31 patients received pelvic lymph node clearance, and the rate of positive lymph nodes was 12.9% （4/31）. Serum prostate-specific antigen （PSA） was 8.9 ± 1.2μg L^-1 after the neoadjuvant therapy and 0.4±0.3μg L^-1 one month after the radical prostatectomy. There were significant differences in the positive surgical margins, seminal vesicle invasion and lymph node metastasis between the neoadjuvant therapy group （n = 12） and the radical prostatectomy group （n = 19, P 〈 0.01）. The resulsts indicates that preoperative hormonal deprivation induced by goserelin and flutamide can decrease clinical and pathological staging, but assessment of its influence on long-term prognosis requires further study.

Effect of Smac on TRAIL-induced Apoptosis of Prostate Cancer Cell Line PC-3 and the Molecular Mechanism

The effect of Smac gene on the TRAIL-induced apoptosis of the prostate cancer cell line PC-3 and the molecular mechanism were investigated. The Smac gene was transfected into PC-3 cells under the induction of liposome. The intrinsic Smac gene expression was detected by Western blotting. After treatment with TRAIL as an apoptosis inducer, in vitro cell growth activity was assayed by MTT colorimetry. The apoptosis rate of PC-3 cells was determined by annexin Ⅴ-FITC and propidium iodide staining flow cytometry. The expression of cellular XIAP and caspase-3 genes was examined by Western blotting. Smac-transfected cells (PC-3/Smac group) had significantly increased Smac protein level as compared with PC-3 controls (P<0.01). After induction with 100–200 ng/mL TRAIL for 12–36 h, cellular proliferation rate in PC-3/Smac group was significantly lower than in PC-3 controls (P<0.05). After induction with 100 ng/mL TRAIL for 24 h, the apoptosis rate in PC-3/Smac group was significantly enhanced as compared with that of PC-3 controls (P<0.05). Accordingly, the XIAP expression level was down-regulated significantly (P<0.05) and caspase-3 subunit P20 was up-regulated significantly (P<0.05). It is suggested that the over-expression of cellular Smac can inhibit inhibitor of apoptosis proteins (IAPs), enhance caspases activity and the apoptosis rate of PC-3 cells induced by TRAIL, which may provide a useful experimental basis for prostate cancer therapy.

Ectopic expression of neurotrophic peptide derived from saposin C increases proliferation and upregulates androgen receptor expression and transcriptional activity in human prostate cancer cells

Aim： To determine the effects of the functional domain of saposin C （neurotrophic peptide [NP]） on androgen receptor （AR） expression and transcriptional activity. Methods： We constructed DNA vectors expressing NP or a chimeric peptide of the viral TAT transduction domain and NP （TAT-NP） using gene cloning technology. The effects of ectopic expression of NP or TAT-NP on cell growth were examined by 3-（4, 5-dimethylthiazol-2-yl）-2, 5-diphenyl-2H-tetrazolium bromide （MTT） assay. Reverse transcription-polymerase chain reaction （RT-PCR）, Western blot, transient transfection and reporter gene assays were used to determine the effects of NP on AR expression and activation. Results： NP stimulated proliferation of androgen responsive LNCaP cells in the absence of androgens. RT-PCR and Western blot analyses showed that ectopic expression of NP resulted in induction of AR gene expression, and that the NP-stimulated expression of AR could be synergistically enhanced in the presence of androgens. Furthermore, reporter gene assay results showed that NP could enhance AR transactivation by increasing androgen-inducible gene reporter activity. Conclusion： We provided evidence that ectopic expression of saposin C-originated NP could upregulate AR gene expression and activate the AR transcriptional function in an androgen-independent manner in prostate cancer cells.