Prostate cancer: risk assessment and diagnostic approaches

The successful treatment of prostate cancer relies on detection of the disease at its earliest stages. Although prostate-specific antigen (PSA)-based screening has been a significant advance in the early diagnosis of prostate cancer, identifying specific genetic alterations in a given family or patient will allow more appropriate screening for early disease. Mapping and identification of specific prostate cancer susceptibility genes is slowly becoming a reality. Other prostate cancer risks include a family history, race, and possibly serum markers such as insulin-like growth factor-I (IGF-I). Once a high-risk man is identified, transrectal ultrasound (TRUS)-guided biopsies are the standard to diagnose prostate cancer. Although TRUS is an advance over traditional digitally directed biopsies, it represents a random sampling of the prostate since most lesions cannot be visualized. Newer modalities such as ultrasound contrast agents, pattern recognition, and artificial neural networks (ANNs), applied to TRUS images, may improve diagnostic accuracy. If a man at risk for prostate cancer has undergone a negative TRUS biopsy, the decision for the need for additional biopsies is problematic. Use of PSA derivatives such as free and total PSA and the initial biopsy abnormalities such as atypia or high-grade prostatic intraepithelial neoplasia may define those patients in need of follow-up biopsy.     

Determination of the growth rate of human prostatic cells in primary culture by a morphometric technique

A morphometric technique, based on the measurement of the area of individual cell colonies and of its increase in time, was applied to study the rate of proliferation of human prostatic cells in vitro. The reliability of the method was checked by determination of the growth rate of cultures of the continuous cell line PC93 by the morphometrical technique as well as by counting of the cell number. No significant difference was found in the population doubling times measured by either of these methods. It was therefore concluded that the morphometrical technique could be applied also to study the growth rate of primary cultures of prostatic epithelial cells, in which counting of the cell number is generally impossible. The results showed that, with primary cultures derived from hyperplastic prostates and prostatic carcinomas as well as from the prostatic tumor line PC82, rapid growth occurred during the first two or three days of culture; measurements performed at a later time appeared to be less reliable. It was demonstrated by the effect of serum deprivation on the growth of PC82 cells that the technique described here is, in principle, suitable to monitor the effect of various agents on the growth of cells in primary culture. The method is non-destructive and requires minimal amounts of tissue; it may be applied especially to cultures that cannot be dispersed easily into single cell suspensions.     

Detection of BRAF Mutation in Urine DNA as a Molecular Diagnostic for Canine Urothelial and Prostatic Carcinoma

Urothelial carcinoma (UC) of the lower urinary tract and prostatic carcinoma (PC) are aggressive genitourinary cancers in dogs, characterized by invasion to surrounding tissues and high metastatic potential. Current diagnosis of canine UC and PC requires histopathological examination of a biopsy. Such specimens require specialized medical equipment and are invasive procedures, limiting the availability of diagnosis by histopathology for many canine patients. Access to a non-invasive means to confirm diagnosis is currently an unmet need. Recently, the canine BRAF V595E mutation was detected in ~80% of canine UCs and PCs. In this study, we developed a droplet digital PCR (ddPCR) assay for detection of the canine BRAF V595E mutation in canine urogenital tumors. The assay was evaluated in DNA samples prepared from biopsy specimens of UC (n = 48) and PC (n = 27), as well and non-neoplastic bladder epithelium (n = 38). In addition the assay was assessed for use with DNA isolated from free catch urine samples derived from canine patients with UC (n = 23), PC (n = 3), as well as from dogs with cystitis and healthy controls (n = 37). In all cases the sensitivity to detect the mutant allele was compared with conventional Sanger sequencing. ddPCR had superior sensitivity for detection of the V595E mutation: 75% of UC, 85% of PC, and 0% of control samples were mutation positive, respectively, and the V595E mutation was detected at a level as low as just 1 in 10,000 alleles (~0.01%). Furthermore, the ddPCR assay identified the mutation in free catch urine samples from 83% of canine UC and PC patients, demonstrating its utility as a non-invasive means of diagnosis. We have shown that ddPCR is a sensitive molecular technique with the potential to facilitate accurate and non-invasive means of canine UC and PC diagnosis.     

Current status of molecular markers for early detection of sporadic pancreatic cancer

Pancreatic cancer (PC) is a highly lethal malignancy with near 100% mortality. This is in part due to the fact that most patients present with metastatic or locally advanced disease at the time of diagnosis. Significantly, in nearly 95% of PC patients there is neither an associated family history of PC nor of diseases known to be associated with an increased risk of PC. These groups of patients who comprise the bulk of PC cases are termed as "sporadic PC" in contrast to the familial PC cases that comprise only about 5% of all PCs. Given the insidious onset of the malignancy and its extreme resistance to chemo and radiotherapy, an abundance of research in recent years has focused on identifying biomarkers for the early detection of PC, specifically aiming at the sporadic PC cohort. However, while several studies have established that asymptomatic individuals with a positive family history of PC and those with certain heritable syndromes are candidates for PC screening, the role of screening in identifying sporadic PC is still an unsettled question. The present review attempts to assess this critical question by investigating the recent advances made in molecular markers with potential use in the early diagnosis of sporadic PC - the largest cohort of PC cases worldwide. It also outlines a novel yet simple risk factor based stratification system that could be potentially employed by clinicians to identify those individuals who are at an elevated risk for the development of sporadic PC and therefore candidates for screening.     

Impact of the processes of testicular regression and recrudescence in the prostatic complex of the bat Myotis nigricans (Chiroptera: Vespertilionidae)

Myotis nigricans is a species of vespertilionid bat, whose males show two periods of total testicular regression during the annual reproductive cycle in the northwest São Paulo State, Brazil. Thus, the aim of this study was to investigate the impact of total testicular regression on the prostatic morphophisyology and its regulation. The prostatic complex (PC) of animals from the four periods of the reproductive cycle (active, regressing, regressed, and recrudescence) was analyzed by different histological, morphometric, and immunohistochemical procedures to characterize its variations, analyze its hormonal regulation and evaluate whether the prostate is affected by the processes of testicular regression and recrudescence. The results indicated a decrease in the prostatic parameters from the active to regressed periods, which are related to decreases in the testicular production of testosterone and in the prostatic expression of androgen receptor (AR), estrogen receptor α (ERα) and aromatase. However, in regressed‐recrudescence periods, the prostatic expression of AR, ERα and aromatase increased, indicating the reactivation of the PC. Despite this, the PC appears to have a slower reactivation and seems not to follow the testicular recrudescence in morphological and morphometric terms. With these data, we demonstrate that the prostatic physiology is directly affected by total testicular regression and conclude that it is regulated by testosterone and estrogen, via the production of testosterone by the testes, its conversion to dihydrotestosterone by 5α‐redutase and to estrogen by aromatase, and the activation/deactivation of AR and ERα in epithelial cells, which regulate cell expression and proliferation. J. Morphol. 276:721–732, 2015. © 2015 Wiley Periodicals, Inc.     

A Meta Analysis of Pancreatic Microarray Datasets Yields New Targets as Cancer Genes and Biomarkers

The lack of specific symptoms at early tumor stages, together with a high biological aggressiveness of the tumor contribute to the high mortality rate for pancreatic cancer (PC), which has a five year survival rate of less than 5%. Improved screening for earlier diagnosis, through the detection of diagnostic and prognostic biomarkers provides the best hope of increasing the rate of curatively resectable carcinomas. Though many serum markers have been reported to be elevated in patients with PC, so far, most of these markers have not been implemented into clinical routine due to low sensitivity or specificity. In this study, we have identified genes that are significantly upregulated in PC, through a meta-analysis of large number of microarray datasets. We demonstrate that the biological functions ascribed to these genes are clearly associated with PC and metastasis, and that that these genes exhibit a strong link to pathways involved with inflammation and the immune response. This investigation has yielded new targets for cancer genes, and potential biomarkers for pancreatic cancer. The candidate list of cancer genes includes protein kinase genes, new members of gene families currently associated with PC, as well as genes not previously linked to PC. In this study, we are also able to move towards developing a signature for hypomethylated genes, which could be useful for early detection of PC. We also show that the significantly upregulated 800+ genes in our analysis can serve as an enriched pool for tissue and serum protein biomarkers in pancreatic cancer.     

Interferon-gamma and its functional receptors overexpression in benign prostatic hyperplasia and prostatic carcinoma: parallelism with c-myc and p53 expression

The therapeutic potential of IFN-gamma in prostatic cancer has been documented in several reports, although no immunohistochemical studies of this factor and its receptors in the prostate have been reported. The aim of the present study was to investigate the expression of IFN-gamma and its receptor components (IFN-gamma-Ralpha and IFN-gamma-Rbeta) in normal prostate, benign prostatic hyperplasia (BPH) and prostatic cancer (PC), as well as the possible relationship between this factor and the products of the p53 gene (the wild and mutant forms) and the oncogene c-myc, by means of immunochemical techniques (Western blot, ELISA, and quantification of immunostaining in histological sections). In normal prostate, IFN-gamma and its two receptors were expressed in the basal cells of the epithelium and some stromal cells. In BPH specimens, immunostaining of basal epithelial cells was significantly increased for IFN-gamma and its a receptor, whereas stromal cell immunostaining was significantly increased for IFN-gamma and its b receptor. In addition, columnar epithelial cells immunostained for IFNbeta-Rbeta. PC specimens differed from BPH specimens in the significantly increased immunostaining of epithelial cells for IFN-gamma and its two receptors, and the immunostaining of columnar epithelial cells for IFN-gamma-Ralpha. Immunodetection of wild-p53 was weak and limited to some stromal cells in the three types of specimens. Immunostainings for both mutant-p53 and c-myc were negative in normal prostate, and positive in the epithelium and stromal cells of both BPH and PC specimens. Immunostaining intensity in PC was significantly higher than in BPH. These observations suggest that the expression of both mutant-p53 and c-myc, together with other factors, might be involved in the development of prostatic hyperplasia and neoplasia, while the increased expression of IFN-gamma and its receptors could be regarded as an attempt, although insufficient, to inhibit the uncontrolled cell proliferation.     

Prostate growth and inflammation

INTRODUCTION: There is emerging evidence that prostatic inflammation may contribute to prostate growth either in terms of hyperplastic (BPH) or neoplastic (PC) changes. Inflammation is thought to incite carcinogenesis by causing cell and genome damage, promoting cellular turnover. METHODS: We reviewed our personal experience and the international recent literature on the clinical data supporting a role of inflammation on BPH and PC growth and progression. RESULTS: BPH: Among those patients with self-reported prostatitis, 57% had a history of BPH. MTOPS study showed that men with inflammation had a significantly higher risk of BPH progression and acute urinary retention. We showed that the use of a COX-2 inhibitor in combination with a 5 alpha reductase inhibitor could increase the apoptotic index in BPH tissue. Prostate cancer: A PCR-based analysis of bacterial colonization in PC specimens and normal prostate tissue showed highly suggestive correlation of bacterial colonization and chronic inflammation with a diagnosis of PC. Evidence from genetic studies support the hypothesis that prostate inflammation may be a cause of prostate cancer. De Marzo proposed that proliferative inflammatory atrophy (PIA) is a precursor to PIN and cancer. CONCLUSION: The concept that inflammation can promote prostate growth either in terms of BPH and PC risk remains highly suggestive.     

Proprotein convertases modulate budding and branching morphogenesis of rat ventral prostate

The onset of prostate morphogenesis is involved in the interaction between mesenchyme and epithelium. Proprotein convertases (PCs) activate a variety of growth and differentiation factors including mesenchymal and epithelial factors, such as insulin-like growth factor (IGF) and transforming growth factor-beta (TGF-beta), which induce ductal budding and branching. In this study, we provide evidence that PCs play a critical role in prostatic budding from the urogenital sinus (UGS) and ductal branching morphogenesis of the neonatal rat ventral prostate. PCs were expressed only in the epithelial cells of neonatal rat prostate. PC activity in the ventral prostate was modulated by endogenous androgen. PC inhibition suppressed prostatic budding and branching. Taken together, our data indicates that androgen-induced PCs initiate the development of the prostate.     

Differential gene expression of the key signalling pathway in para‐carcinoma,carcinoma and relapse human pancreatic cancer

Pancreatic cancer (PC) has a high rate of mortality and a poorly understood mechanism of progression. Investigation of the molecular mechanism of PC and exploration of the specific markers for early diagnosis and specific targets of therapy are key points to prevent and treat PC effectively and to improve their prognosis. In our study, expression profiles experiment of para‐carcinoma, carcinoma and relapse human PC was performed using Agilent human whole genomic oligonucleotide microarrays with 45 000 probes. Differentially expressed genes related with PC were screened and analysed further by Gene Ontology term analysis and Kyoto encyclopaedia of genes and genomes pathway analysis. Our results showed that there were 3853 differentially expressed genes associated with pancreatic carcinogenesis and relapse. In addition, our study found that PC was related to the Jak–STAT signalling pathway, PPAR signalling pathway and Calcium signalling pathway, indicating their potential roles in pancreatic carcinogenesis and progress. Copyright © 2013 John Wiley & Sons, Ltd.     

经直肠B 超诊断前列腺增生的图像特征及其临床意义

目的:探讨前列腺增生(BPH)经直肠B超检查的图像特征及其对治疗的指导作用。方法:回顾性分析103例经术后病理组织学诊断确诊的BPH患者临床资料,总结其经直肠B超图像特征,并根据B超诊断结果选择适宜治疗方法。结果:经直肠B超检出BHP 98例,2例误诊,3例漏诊,诊断符合率、误诊率、漏诊率分别为95.14%、1.94%、2.91%;B超图像显示BPH病灶呈细小均匀光点,前列腺变圆、增大,内腺以低回声为主,外腺以低回声及中、低混合回声为主;包膜清晰占62.92%;98例确诊为BPH的患者当中,66例行经尿道电切术、16例在B超引导下行无水乙醇注射,16例行开放性手术。结论:直肠B超通过观察回声、内外腺前后径比例、有无包膜、分界情况等准确诊断前列腺增生,同时可通过测量前列腺重量指导临床治疗。     

Grey-Scale Ultrasound in the Imaging of Urinary Tract Disease

Grey-scale ultrasound defines smaller renal lesions that had previously been appreciated and is able to define associated lesions of the liver such as metastases and cysts. The appropriate technique to delineate the normal anatomy of the kidney is described. Ultrasound plays a central role in the identification and characterization of renal mass lesions thus leading to appropriate further work up. In renal transplant evaluation ultrasound is useful as a complementary modality to other imaging studies permitting the recognition of pelvic fluid collections, rejection, and hydronephrosis. Specific findings are present in renal abscess, perirenal abscess, and in several of the renal cystic diseases. Adrenal lesions can be identified and clarified. In the lower urinary tract, ultrasound can identify bladder and prostatic tumors.Ultrasound provides a rapid, safe and non-invasive modality which is complementary to other imaging techniques in the diagnosis of urinary tract disease.     

Growth factor involvement and oncogene expression in prostatic tumours

The effects of EGF, TGF alpha and 5 alpha-dihydrotestosterone on the growth of a prostatic epithelial cell line have been evaluated in clonal growth assays. Similar bioassay systems have been used to identify tumour-associated growth promoters derived from a human prostatic carcinoma cell line (PC3). Growth factor activity was associated with proteins of Mr 20-30 kDa. In a separate study, EGF receptor concentration and cellular proto-oncogene expression was assessed in prostatic tumour samples. In prostatic carcinoma samples, strong correlation was observed between EGF receptor concentration and c-myc expression. There were no significant correlations between EGF receptor concentration and tumour grade or androgen receptor content in carcinoma samples. EGF receptor concentration was significantly higher in prostatic carcinoma specimens than in BPH.     

Theoretical and experimental analysis of analyte transport in a fiber-optic, protein C immuno-biosensor

Protein C (PC) is an important anticoagulant in human blood plasma, and early diagnosis of PC deficiency is critical for preventing dangerous thromboembolic complications. A fiber-optic PC immuno-biosensor has been under development in our research group for real-time PC-deficiency diagnosis. The sensor has demonstrated a good sensitivity and specificity for quantifying PC in buffered solutions. However, for plasma samples, with a limited sample reaction time, the sensor produced only 30% of the signal intensity of PC in buffer. The high plasma viscosity (1.9 cP) was speculated as the major reason for signal intensity reduction. In this investigation, the sensing performance of the fiber-optic PC biosensor is systematically characterized in terms of physical and chemical properties of the sample media. Theoretical and experimental analyses indicate that the reduced diffusion rate of PC molecules in viscous samples caused the sensing system to be more mass-transfer-limited. Convective flow of sample/reagent solutions during immunoreactions can increase the rate of the analyte mass transport from the bulk solution to the sensor surface, with reaction kinetics changing from mass-transfer-limited to reaction-limited as flow velocity increases. It was shown that PC sensor performance was significantly improved for plasma samples with convection. The effect of the flow velocity and incubation times for samples and reagents on the sensor performance was also systematically analyzed to optimize the assay protocol for PC sensing. Currently, a 6-cm-long immuno-biosensor is capable of quantifying PC in plasma (1 mL) in the heterozygous PC deficiency range (0.5 to 2.5 microg/mL) within 5 minutes, at an average signal-to-noise ratio of 50.     

Immunoexpression of tumour necrosis factor-alpha and its receptors 1 and 2 correlates with proliferation/apoptosis equilibrium in normal, hyperplasic and carcinomatous human prostate

Immunohistochemical and semiquantitative study of TNF-alpha, its receptors types 1 (TNFR1) and 2 (TNFR2), cell proliferation (Ki-67 nuclear antigen), and apoptosis (Tunel method) was carried out in human prostates, in normal healthy conditions, as well as in benign prostatic hyperplasia (BPH) and prostatic carcinoma (PC). Cell proliferation was higher in BPH than in normal prostates, and even higher in PC, mainly in neoformations showing a microglandular pattern. The apoptotic index was similar in BPH and normal prostates, and increased significantly in PC with independence of the pattern. In BPH, immunoreaction to TNF-alpha decreased as compared with that of normal prostates, while immunoreactions to both TNF-alpha receptors increased. This suggests a feedback downregulation of the factor, and that the low TNF-alpha activity in BPH are compensated by the increased amount of receptors. In PC, immunoreaction to TNF-alpha and its two receptors increased markedly, suggesting that the TNF-induced effects are also increased. Contrarily to cell proliferation immunoexpression, PC reaction to TNFR2 was stronger in the papillar pattern than in the micrograndular pattern, and this suggests an inverse correlation between TNFR2 expression and cell proliferation.     

超声在糖尿病肾病诊断中的应用价值

由于快速变化的生活方式,我国糖尿病的患病率呈逐年上升趋势。糖尿病肾病(diabetic nephropathy,DN)是糖尿病最常见、最严重的微血管病变并发症之一,并且已经成为全球终末期肾病的最常见病因。因此,早期诊断、早期治疗是延缓DN进展的重点。超声是临床评价肾脏形态、功能常用的检查方法,与血、尿实验室检查相比,具有方便、快捷、无创、经济的优势。随着科学技术的发展,越来越多的超声新技术应用于临床,极大的丰富了诊断信息。本文就各项超声检查技术在检测DN患者肾脏体积、实质回声、血流动力学改变中的应用价值作一综述。得出结论:在DN早期血、尿实验室检查正常时超声已经可以发现肾脏体积、血流动力学发生了变化。因此,超声在DN的早期诊断、动态监测病程进展方面所发挥的作用是其他检查方法所不可替代的。三维超声技术和超声弹性成像在DN患者肾脏功能评价方面有着广泛研究空间及临床应用前景。     

Inhibition of experimentally induced mouse prostatic hyperplasia by castration or steroid antagonist administration.

Mouse prostatic hyperplasia has been induced experimentally by implanting fetal urogenital sinus tissue into the prostate gland of syngeneic mice. We compared the effects of castration and steroid antagonist administration on the growth of the prostate gland during both the early (15 days) and late (30 days) phases of prostatic enlargement. Castration at the time of induction of prostatic hyperplasia is by far the most effective method of inhibiting prostatic overgrowth. A comparison of castration for 7 days with the short-term (7 days) administration of steroid antagonists showed that during the early phase of prostatic enlargement castration is more effective than antiandrogen, which is more effective than 5 alpha-reductase inhibitors. In the late phase of mouse prostatic enlargement, castration for 7 days is less effective than treatment with either antiandrogen or a 5 alpha-reductase inhibitor. Our data indicate that treatment with a combination of an antiestrogen (keoxifene) with a 5 alpha-reductase inhibitor (in particular, 6-methylene progesterone) is the most effective combination for reducing prostatic overgrowth. The antiestrogen (keoxifene) treatment alone was ineffective in both the early and late phases of prostatic overgrowth.     

拉曼光谱技术在肿瘤检测中的应用

癌症是威胁人类健康和生命的严重疾病之一,早期诊断与及时治疗是提高癌症患者生存率的最有效途径。激光拉曼光谱技术作为一种非侵入性的检测技术,可以无损伤地提供丰富的分子结构特征和物质成分信息,从分子水平上反映癌变组织与正常组织之间的结构差异,从而可用于癌症的早期诊断。综述了激光拉曼光谱技术在皮肤癌、鼻咽癌、肺癌、胃癌、结肠癌、乳腺癌及前列腺癌诊断中的研究进展,并对拉曼光谱技术在癌症诊断中的发展方向和应用前景作了进一步的展望,为癌症的早期检测和诊断技术的应用研究提供参考依据。     

Independent signals determine the subcellular localization of NEP in prostate cancer cells

NEP (Neutral endopeptidase 24.11) is a cell surface enzyme that hydrolyzes bioactive neuropeptides implicated in the transition from androgen-dependent prostate cancer (PC) to androgen-independent PC. We report the cloning and sequence analyses of NEP cDNAs from human androgen-responsive LNCaP PC cells and prostatic stromal cells. To investigate the functional role of a nuclear localization sequence (NLS) detected within the N-terminus and of an endoplasmic reticulum retention signal within the C-terminus, NEP-GFP expression vectors were constructed containing the whole NEP gene, fragments encoding the N-terminus/C-terminus of the protein (5(')NEP-GFP/3(')NEP-GFP), and 5(')NEP-GFP constructs lacking the NLS. 3(')NEP-GFP transfected cells showed plasma membrane/cytoplasmic fluorescence whereas the 5(')NEP-GFP fusion protein was also detected in the nucleus. The omission of the NLS resulted in no reduction in nuclear and an increase in cytoplasmic staining. The results suggest that the analyzed structural motifs determine the subcellular distribution of NEP in epithelial LNCaP PC cells and stromal prostatic cells and therefore could be responsible for the altered cellular localization of NEP observed in PC.     

Assessment of fine needle aspiration as a screening test for occult prostatic carcinoma

As part of an ongoing study of objective parameters of prognostic value in prostatic carcinoma, a routine procedure was developed to aspirate all prostates prior to surgery. These targets were different from those of other workers in the field of prostatic fine needle aspiration (FNA), who generally advocate that FNA be confined to suspicious nodules. The aspirations were performed by a large group of practicing urologists who had no special training in prostatic FNA except for guidelines provided by their peers and information available in the literature. This approach permitted an assessment of the performance of FNA as a screening test rather than as a diagnostic procedure. During the period from January 1983 to February 1987, 1,683 patients had prostatic FNAs performed (plus subsequent histologic study). The following diagnoses were rendered: "inadequate/scanty specimen" in 625 cases (37%), "negative/atypical" in 844 cases (50%) and "suspicious/positive" in 214 cases (13%). Histologic examination showed stage A1 prostatic adenocarcinoma in 18 patients. The cytologic diagnoses on these 18 patients were inadequate/scanty in 3 (17%), negative/atypical in 13 (72%) and suspicious/positive in 2 (11%). Of the 214 patients with a positive/suspicious diagnosis by FNA, the diagnosis of prostatic carcinoma was confirmed by tissue evidence in 200; the other 14 patients had either no evidence of prostatic carcinoma on surgical biopsy (needle biopsy/transurethral resection/suprapubic prostatectomy) or had no surgical biopsy. Eight of the 14 patients developed clinical evidence of carcinoma, 1 died of urinary bladder carcinoma and 1 was lost to follow-up. In the remaining four patients, there is still no evidence of prostatic carcinoma after about one-and-one-half years of follow-up. These results indicate that (1) specialized training is required in order to obtain adequate smears by prostatic FNA; (2) prostatic FNA is not a good screening technique for detecting stage A1 prostatic carcinoma; and (3) a positive diagnosis by prostatic FNA, even when not confirmed by tissue biopsy, is still an indication of disease.