Prostate Cancer Antigen Research Articles

Electrochemical Detection of Prostate Cancer Biomarker PCA3 Using Specific RNA-Based Aptamer Labelled with Ferrocene

This paper reports on a feasibility study of electrochemical in-vitro detection of prostate cancer biomarker PCA3 (prostate cancer antigen 3) in direct assay with specific RNA aptamer labelled with a redox group (ferrocene) and immobilized on a screen-printed gold electrode surface. The cyclic voltammograms and electrochemical impedance spectroscopy methods yield encouraging results on the detection of PCA3 in a range of concentrations from 1 μg/mL down to 0.1 ng/mL in buffer solutions. Both anodic and cathodic current values in cyclic voltammograms measurements and charge transfer resistance values in electrochemical impedance spectroscopy experiments correlate with the PCA3 concentration in the sample. Kinetics studies of the binding of the PCA3 to our aptamer demonstrated high specificity of the reaction with a characteristic affinity constant of approximately 4·10−10 molar. The results of this work provide a background for the future development of novel, highly sensitive and cost-effective diagnostic methodologies for prostate cancer detection.

PCA3 controls chromatin organization and p53 signal activation by regulating LAP2α-lamin A complexes.

Prostate cancer antigen 3 (PCA3) is a prostate cancer-specific long noncoding RNA (lncRNA). Here, we report that lncRNA PCA3 plays a role in prostate cancer progression that is mediated by nucleoplasmic lamins. PCA3 interacts with the C-terminal region of lamina-associated polypeptide (LAP) 2α. The C-terminal region of LAP2α includes tumor suppressor protein retinoblastoma (pRb)- and lamin-binding domains, and it is necessary for the regulation and stabilization of the nucleoplasmic pool of lamin A. PCA3 inhibits the interaction of LAP2α with lamin A through binding with the C-terminus of LAP2α. The level of nucleoplasmic lamin A/C is increased by knockdown of PCA3. Together, the level of LAP2α within the nucleus is increased by PCA3 knockdown. In PCA3 knockdown cells, the levels of HP1γ, trimethylation of Lys9 on histone H3 (H3K9me3), and trimethylation of Lys36 on histone H3 (H3K36me3) are upregulated. In contrast, trimethylation of Lys4 on histone H3 (H3K4me3) is downregulated. We further demonstrate that activation of the p53 signaling pathway and cell cycle arrest are promoted in the absence of PCA3. These findings support a unique mechanism in which prostate cancer-specific lncRNA controls chromatin organization via regulation of the nucleoplasmic pool of lamins. This proposed mechanism suggests that cancer progression may be mediated by nuclear lamins.

Immunotherapy of prostate cancer using novel synthetic DNA vaccines targeting multiple tumor antigens.

Prostate cancer is a prevalent cancer in men and consists of both indolent and aggressive phenotypes. While active surveillance is recommended for the former, current treatments for the latter include surgery, radiation, chemo and hormonal therapy. It has been observed that the recurrence in the treated patients is high and results in castration resistant prostate cancer for which treatment options are limited. This scenario has prompted us to consider immunotherapy with synthetic DNA vaccines, as this approach can generate antigen-specific tumor-killing immune cells. Given the multifocal and heterogeneous nature of prostate cancer, we hypothesized that synthetic DNA vaccines targeting different prostate specific antigens are likely to induce broader and improved immunity who are at high risk as well as advanced clinical stage of prostate cancer, compared to a single antigen approach. Utilizing a bioinformatics approach, synthetic enhanced DNA vaccine (SEV) constructs were generated against STEAP1, PAP, PARM1, PSCA, PCTA and PSP94. Synthetic enhanced vaccines for prostate cancer antigens were shown to elicit antigen-specific immune responses in mice and the anti-tumor activity was evident in a prostate tumor challenge mouse model. These studies support further evaluation of the DNA tools for immunotherapy of prostate cancer and perhaps other cancers.

Long non-coding RNA PCA3 inhibits lipid accumulation and atherosclerosis through the miR-140-5p/RFX7/ABCA1 axis

ObjectiveThe purpose of this study was to explore the role of long noncoding RNA (lncRNA) prostate cancer antigen 3 (PCA3) in atherosclerosis and the underlying mechanism. MethodsThe Gene Expression Omnibus (GEO) datasets were used to divide differentially expressed lncRNAs, microRNAs (miRNAs), and mRNAs. The expression of PCA3, miR-140-5p, RFX7 and ABCA1 were determined by qPCR or Western blot in ox-LDL-treated macrophages. Macrophage lipid accumulation s was evaluated using the Oil Red O staining and high-performance liquid chromatography. Target relationships among PCA3, miR-140-5p, RFX7, and ABCA1 promoter area were validated via dual-luciferase reporter gene assay or chromatin immunoprecipitation assay. The apoE−/− mouse model in vivo was designed to evaluate the effect of PCA3 on the reverse cholesterol transport (RCT) and atherosclerosis. ResultsPCA3 was down-regulated in foam cells, whereas miR-140-5p was highly expressed. Overexpression of PCA3 promoted ABCA1-mediated cholesterol efflux and reduced lipid accumulation in macrophages. Besides, RFX7 bound to the ABCA1 promoter and increased ABCA1 expression. Targeted relationships and interactions on the expression between miR-140-5p and PCA3 or RFX7 were elucidated. PCA3 up-regulated ABCA1 expression by binding to miR-140-5p to up-regulate RFX7 and ABCA1 expression in macrophages. PCA3 promoted RCT and impeded the progression of atherosclerosis by sponging miR-140-5p in apoE−/− mice. Meanwhile, miR-140-5p also inhibit ABCA1 expression via downregulation of RFX7 to impede RCT and aggravate atherosclerosis. ConclusionslncRNA PCA3 promotes ABCA1-mediated cholesterol efflux to inhibit atherosclerosis through sponging miR-140-5p and up-regulating RFX7.

PCA3 in Prostate Cancer.

Prostate cancer antigen 3 (PCA3) is a urinary biomarker for prostate cancer and has demonstrated a good specificity and sensitivity representing a minimally invasive test.PCA3 assay could be useful in combination with PSA to suggest an eventual rebiopsy in men who have had one or more previous negative prostate biopsies.Combination of multiple tumor biomarkers will be the trend in the near future to achieve the goal of evaluate the aggressiveness of cancer and at the same time reducing the number of unnecessary biopsies.

Influence of prostate cancer status on the prevalence of medication-related osteonecrosis of the jaw

The aim of this study was to evaluate the risk of osteonecrosis of the jaw (ONJ) in patients with prostate cancer, particularly the relationship between prostate cancer progression and ONJ development. This single-center, retrospective, observational study included 113 patients who received zoledronic acid or denosumab for prostate cancer with bone metastasis between January 2012 and March 2020. The risk of ONJ was evaluated regarding age; antiresorptive drugs; duration of antiresorptive treatment; prostate cancer status, including castration-resistant prostate cancer (CRPC) and prostate-specific antigen level; chemotherapy; radium-223 treatment; corticosteroid treatment; diabetes mellitus; and dental extractions. Overall, 28 patients had ONJ; 10 patients received zoledronic acid and 18 patients received denosumab. Multiple logistic regression analysis demonstrated that CRPC (odds ratio=6.01; 95% confidence interval, 1.76-20.05; P=.004) and dental extractions (odds ratio=12.40; 95% confidence interval, 3.42-44.70; P < .001) were significantly associated with ONJ. In addition, antiresorptive treatment lasting more than 1 year partially mediated between CRPC and development of ONJ. CRPC and dental extraction are risk factors for developing ONJ, and antiresorptive treatment lasting more than 1 year is a partial mediator between CRPC and ONJ.

Influence of the Molecular Orientation and Ionization of Self-Assembled Monolayers in Biosensors: Application to Genosensors of Prostate Cancer Antigen 3

Electrochemical sensing depends on the immobilization of biorecognition elements and charge transfer to the electrode, which can be tuned and sometimes controlled using self-assembled monolayers (SAMs) as matrices. In this study, we show that an efficient immobilization of an ssDNA probe to detect the prostate cancer antigen 3 biomarker is achieved even for less organized SAMs provided that the terminal groups were ionized. These conclusions were reached by comparing the biosensors made with 11-mercaptoundecanoic acid (11-MUA) prepared in ethanol and thioglycolic acid (mercaptoacetic acid: MAA) prepared in ethanolic and aqueous solvents. The highest sensitivity with electrochemical impedance spectroscopy was observed for sensors assembled over MAA monolayers on gold prepared in ethanol and water (at pH 12.5), with limits of detection of 1.2 × 10–9 and 1.7 × 10–9 mol L–1, respectively. The biosensors made on MAA films prepared in water at pH 7.0 and 2.5 were not efficient because they are mostly terminated by protonated carboxylic acid groups, according to sum-frequency generation vibrational and polarization modulation-infrared reflection-absorption (PM-IRRAS) spectroscopies, which prevent an adequate attachment of the biomarker. Well-organized SAMs of 11-MUA also showed good detection performance, but the limit of detection was not as low, 2.1 × 10–9 mol L–1, probably due to its long chains that decrease the charge transfer. Therefore, the matrix fabrication method can control the molecular assembly of biosensors and hence their performance.

Diagnostic performance of prostate cancer antigen 3 and the Prostate Health Index in detecting overall and clinically significant prostate cancer in men at first biopsy: A meta-analysis.

To evaluate the diagnostic value of prostate cancer antigen 3 and the Prostate Health Index for the detection of overall and clinically significant prostate cancer at initial biopsy. A search was conducted in the online databases PubMed, Embase and the Cochrane database, and relevant articles published up to 23 February 2020 were extracted. Twenty studies including 10376 patients were included in the meta-analysis. The pooled sensitivity and specificity were 0.55 (95% confidence interval 0.53-0.57) and 0.74 (95% confidence interval 0.72-0.75) for prostate cancer antigen 3 and 0.88 (95% confidence interval 0.86-0.90) and 0.36 (95% confidence interval 0.34-0.38) for the Prostate Health Index. The area under the curve was 0.72 for prostate cancer antigen 3 and 0.76 for the Prostate Health Index. The combination of prostate cancer antigen 3 and the Prostate Health Index had a higher area under the curve (0.79) and diagnostic odds ratio (5.83) than the use of Prostate Health Index (area under the curve 0.75, diagnostic odds ratio 4.69) or prostate cancer antigen 3 (area under the curve 0.77, diagnostic odds ratio 4.84) alone. For clinically significant prostate cancer detection, the pooled sensitivity and specificity were 0.80 (95% confidence interval 0.76-0.84) and 0.53 (95% confidence interval 0.50-0.55), respectively, for prostate cancer antigen 3, and 0.77 (95% confidence interval 0.71-0.82) and 0.64 (95% confidence interval 0.61-0.67), respectively, for the Prostate Health Index. The area under the curve was 0.71 for prostate cancer antigen 3 and 0.77 for the Prostate Health Index. Both the Prostate Health Index and prostate cancer antigen 3 showed acceptable and similar results for the detection of overall and clinically significant prostate cancer at first biopsy. A combination of these two diagnostic tests may be more helpful than the use of either test alone in prostate cancer management.

Use of the MyProstateScore Test to Rule Out Clinically Significant Cancer: Validation of a Straightforward Clinical Testing Approach.

The MyProstateScore test was validated for improved detection of clinically significant (grade group ≥2) prostate cancer relative to prostate specific antigen based risk calculators. We sought to validate an optimal MyProstateScore threshold for clinical use in ruling out grade group ≥2 cancer in men referred for biopsy. Biopsy naïve men provided post-digital rectal examination urine prior to biopsy. MyProstateScore was calculated using the validated, locked multivariable model including only serum prostate specific antigen, urinary prostate cancer antigen 3 and urinary TMPRSS2:ERG. The MyProstateScore threshold approximating 95% sensitivity for grade group ≥2 cancer was identified in a training cohort, and performance was measured in 2 external validation cohorts. We assessed the 1) overall biopsy referral population and 2) population meeting guideline based testing criteria (ie, prostate specific antigen 3-10, or <3 with suspicious digital rectal examination). Validation cohorts were prospectively enrolled from academic (977 patients, median prostate specific antigen 4.5, IQR 3.1-6.0) and community (548, median prostate specific antigen 4.9, IQR 3.7-6.8) settings. In the overall validation population (1,525 patients), 338 men (22%) had grade group ≥2 cancer on biopsy. The MyProstateScore threshold of 10 provided 97% sensitivity and 98% negative predictive value for grade group ≥2 cancer. MyProstateScore testing would have prevented 387 unnecessary biopsies (33%), while missing only 10 grade group ≥2 cancers (3.0%). In 1,242 patients meeting guideline based criteria, MyProstateScore ≤10 provided 96% sensitivity and 97% negative predictive value, and would have prevented 32% of unnecessary biopsies, missing 3.7% of grade group ≥2 cancers. In a large, clinically pertinent biopsy referral population, MyProstateScore ≤10 provided exceptional sensitivity and negative predictive value for ruling out grade group ≥2 cancer. This straightforward secondary testing approach would reduce the use of more costly and invasive procedures after screening with prostate specific antigen.

Diagnosis accuracy of PCA3 level in patients with prostate cancer: a systematic review with meta-analysis.

ABSTRACTBackground:The diagnostic value and suitability of prostate cancer antigen 3 (PCA3) for the detection of prostate cancer (PCa) have been inconsistent in previous studies. Thus, the aim of the present meta-analysis was performed to systematically evaluate the diagnostic value of PCA3 for PCa.Materials and Methods:A meta-analysis was performed to search relevant studies using online databases EMBASE, PubMed and Web of Science published until February 1st, 2019. Ultimately, 65 studies met the inclusion criteria for this meta-analysis with 8.139 cases and 14.116 controls. The sensitivity, specificity, positive likelihood ratios (LR+), negative likelihood ratios (LR−), and other measures of PCA3 were pooled and determined to evaluate the diagnostic rate of PCa by the random-effect model.Results:With PCA3, the pooled overall diagnostic sensitivity, specificity, LR+, LR−, and 95% confidence intervals (CIs) for predicting significant PCa were 0.68 (0.64-0.72), 0.72 (0.68-0.75), 2.41 (2.16-2.69), 0.44 (0.40-0.49), respectively. Besides, the summary diagnostic odds ratio (DOR) and 95% CIs for PCA3 was 5.44 (4.53-6.53). In addition, the area under summary receiver operating characteristic (sROC) curves and 95% CIs was 0.76 (0.72-0.79). The major design deficiencies of included studies were differential verification bias, and a lack of clear inclusion and exclusion criteria.Conclusions:The results of this meta-analysis suggested that PCA3 was a non-invasive method with the acceptable sensitivity and specificity in the diagnosis of PCa, to distinguish between patients and healthy individuals. To validate the potential applicability of PCA3 in the diagnosis of PCa, more rigorous studies were needed to confirm these conclusions.

A Lateral Flow Immunoassay for Prostate‐Specific Antigen Detection Using Silica‐Coated CdSe@ZnS Quantum Dots

Protein detection technologies are important for early disease diagnosis because of their advantages over biopsy testing. Considering the diagnostic potential of prostate‐specific antigen (PSA) in prostate cancer, in this study, we present a lateral flow immunoassay (LFIA) for successful detection of PSA by using silica‐coated CdSe@ZnS quantum dots (QD@SiO2). The QD@SiO2 were synthesized using a reverse microemulsion method. The average size of the synthesized nanoparticles (NPs) was 51.76 nm, and their quantum yield (QY) was relatively high (36.5%). PSA detection was performed using LFIA on a strip. The QD@SiO2 surface was modified by conjugating the anti‐PSA antibody to detect the PSA. At concentrations above 1.0754 ng/mL, PSA was detected using the designed LFIA system without any nonspecific binding. The proposed QD@SiO2 has other bioapplications as well.

11C-choline positron emission tomography/computed tomography for detection of disease relapse in patients with history of biochemically recurrent prostate cancer and prostate-specific antigen ≤0.1 ng/ml.

The objective was to evaluate the diagnostic performance of surveillance11 C-choline positron emission tomography/computed tomography (PET/CT) for the detection of disease relapse in patients with a history of biochemically recurrent (BCR) prostate cancer (PCa) and prostate-specific antigen (PSA) ≤0.1 ng/ml. We included patients who had been treated for BCR PCa and had a surveillance11 C-choline PET/CT at serum PSA ≤0.1 ng/ml. Positive surveillance PET/CT was defined as a study that identified a new tracer-avid lesion or new tracer uptake in a previously treated lesion or both. Findings were confirmed against a composite radiologic-pathologic gold standard. Time to recurrence association analyses were performed for disease relapse risk with the use of Cox proportional hazards regression. In total, 13 (12.1%) of the 107 patients had positive surveillance PET/CT scans, confirmed on pathologic assessment (n = 5) and subsequent imaging (n = 8). Among these 13 patients, ten had distant metastases, two had local recurrence, and one had both. Nine of the ten patients with metastases had oligometastatic disease defined as the presence of ≤3 metastases. Serum PSA became detectable again in only seven patients with positive surveillance PET/CT, after a mean interval from surveillance PET/CT of 292 days (range: 105-543 days). We identified an association of N stage with increased risk of recurrence (hazard ratio = 3.85; P = 0.036) although this was not significant after accounting for multiple testing. Surveillance11 C-choline PET/CT can detect early disease relapse at serum PSA ≤0.1 ng/ml in patients with a history of BCR PCa.

Apalutamide and Overall Survival in Prostate Cancer

BackgroundThe phase 3 SPARTAN study evaluated apalutamide versus placebo in patients with nonmetastatic castration-resistant prostate cancer (nmCRPC) and prostate-specific antigen doubling time of ≤10 mo. At primary analysis, apalutamide improved median metastasis-free survival (MFS) by 2 yr and overall survival (OS) data were immature. ObjectiveWe report the prespecified event-driven final analysis for OS. Design, setting, and participantsA total of 1207 patients with nmCRPC (diagnosed by conventional imaging) were randomised 2:1 to apalutamide (240mg/d) or placebo, plus on-going androgen deprivation therapy. After MFS was met and the study was unblinded, 76 (19%) patients still receiving placebo crossed over to apalutamide. Outcome measurements and statistical analysisOS and time to cytotoxic chemotherapy (TTChemo) were analysed by group-sequential testing with O’Brien-Fleming-type alpha spending function. Results and limitationsAt median 52-mo follow-up, 428 deaths had occurred. The median treatment duration was 32.9 mo for apalutamide group and 11.5 mo for placebo group. Median OS was markedly longer with apalutamide versus placebo, reaching prespecified statistical significance (73.9 vs 59.9 mo, hazard ratio [HR]: 0.78 [95% confidence interval {CI}, 0.64–0.96]; p=0.016). Apalutamide also lengthened TTChemo versus placebo (HR: 0.63 [95% CI, 0.49–0.81]; p=0.0002). Discontinuation rates in apalutamide and placebo groups due to progressive disease were 43% and 74%, and due to adverse events 15% and 8.4%, respectively. Subsequent life-prolonging therapy was received by 371 (46%) patients in the apalutamide arm and by 338 (84%) patients in the placebo arm including 59 patients who received apalutamide after crossover. Safety was consistent with previous reports; when adverse events were adjusted for treatment exposure, rash had the greatest difference of incidence between the apalutamide and placebo groups. ConclusionsExtension of OS with apalutamide compared with placebo conferred impactful benefit in patients with nmCRPC. There was a 22% reduction in the hazard of death in the apalutamide group despite 19% crossover (placebo to apalutamide) and higher rates of subsequent therapy in the placebo group. Patient summaryWith data presented herein, all primary and secondary study end points of SPARTAN were met; findings demonstrate the value of apalutamide as a treatment option for nonmetastatic castration-resistant prostate cancer.

Advances in Precision Oncology: Targeted Thorium-227 Conjugates As a New Modality in Targeted Alpha Therapy.

Targeted α therapy (TAT) offers the potential for the targeted delivery of potent α-particle-emitting radionuclides that emit high linear energy transfer radiation. This leads to a densely ionizing radiation track over a short path. Localized radiation induces cytotoxic, difficult-to-repair, clustered DNA double-strand breaks (DSBs). To date, radium-223 (223Ra) is the only TAT approved for the treatment of patients with metastatic castration-resistant prostate cancer. Thorium-227 (227Th), the progenitor nuclide of 223Ra, offers promise as a wider-ranging alternative due to the availability of efficient chelators, such as octadentate 3,2-hydroxypyridinone (3,2-HOPO). The 3,2-HOPO chelator can be readily conjugated to a range of targeting moieties, enabling the generation of new targeted thorium-227 conjugates (TTCs). This review provides a comprehensive overview of the advances in the preclinical development of TTCs for hematological cancers, including CD22-positive B cell cancers and CD33-positive leukemia, as well as for solid tumors overexpressing renal cell cancer antigen CD70, membrane-anchored glycoprotein mesothelin in mesothelioma, prostate-specific membrane antigen in prostate cancer, and fibroblast growth factor receptor 2. As the mechanism of action for TTCs is linked to the formation of DSBs, the authors also report data supporting combinations of TTCs with inhibitors of the DNA damage response pathways, including those of the ataxia telangiectasia and Rad3-related protein, and poly-ADP ribose polymerase. Finally, emerging evidence suggests that TTCs induce immunogenic cell death through the release of danger-associated molecular patterns. Based on encouraging preclinical data, clinical studies have been initiated to investigate the safety and tolerability of TTCs in patients with various cancers.

Abstract LB-382: Engineered NK92MICD64 cell docking platform as a combination therapy approach for prostate cancer

Abstract Natural killer (NK) cells are cytotoxic lymphocytes that detect and kill virally infected or malignant cells. Targeting NK cells to solid tumors can be improved by engineering NK cells to express CD64 (FcγR1), a high affinity receptor for human IgG Fc, in combination with therapeutic monoclonal antibodies (mAbs). CD64 can capture soluble mAbs with two to three orders of magnitude higher affinity than CD16A (FcγIIIA) and mediates tumor cell killing when anti-tumor mAb is bound. This docking platform allows for switchable targeting elements to effectively direct the NK cells to multiple tumor antigens. We are targeting several relevant prostate cancer (PCa) antigens including TROP2, a transmembrane glycoprotein that is overexpressed in metastatic PCa, and FAP, a membrane bound serine protease expressed by cancer-associated fibroblasts in the tumor microenvironment. For all cytotoxicity experiments, we used an immortalized human PCa stromal cell line that highly expresses FAP (hPrCSC-44) and a human PCa cell line that highly expresses TROP2 (DU145). Cell killing was measured using the Delfia EuTDA cytotoxicity assay. First, we tested for mediation of NK92MICD64 cell antibody dependent cell cytotoxicity (ADCC) using a titration of anti-FAP or anti-TROP2 mAb (5 to 0 µg/mL) and saw a concentration dependent effect on cell killing. Next, CD64 capture of soluble anti-FAP or anti-TROP2 mAb was tested by flow cytometry. Over 98% of the NK92MICD64 cells incubated with the therapeutic mAbs were positively stained, indicating that the mAbs dock to CD64 and could direct tumor cell killing. Therapeutic efficacy of anti-FAP or anti-TROP2 mAb bound to NK92MICD64 cells (αFAP-NK92MICD64 and αTROP2-NK92MICD64) was tested by incubating the effector cells with hPrCSC-44 or DU145 cells at several effector:target (E:T) ratios. Potent cytotoxicity was observed and the % specific release was significantly higher than the NK92MICD64 cells alone. Cytotoxicity dropped to baseline levels when the anti-tumor mAb was switched to an isotype control, indicating that the mAb-directed cell killing occurs by an antigen-selective mechanism. After seeing the success of the monotherapies, we wanted to evaluate αFAP-NK92MICD64 and αTROP2-NK92MICD64 cells as a combination therapy. Previous studies have reported a synergistic effect of combination therapies that target both the tumor stroma and malignant cells. To test our approach, hPrCSC-44 and DU145 cells were co-incubated with αFAP-NK92MICD64 and αTROP2-NK92MICD64 cells at several E:T ratios. We observed potent cytotoxicity and % specific release was significantly higher than the NK92MICD64 cells alone. In conclusion, CD64 on NK92MI cells facilitated ADCC and cytokine production demonstrating functional activity in our prostate cancer models. The use of CD64 as a docking platform for therapeutic mAbs was shown to effectively mediate tumor cell killing. Together, these data suggest the potential for our combination cell therapy to be developed as a new therapeutic approach for PCa. Citation Format: Hallie M. Hintz, Aaron M. LeBeau. Engineered NK92MICD64 cell docking platform as a combination therapy approach for prostate cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr LB-382.

Electroporation-Based Treatments in Urology.

The observation that an application of a pulsed electric field (PEF) resulted in an increased permeability of the cell membrane has led to the discovery of the phenomenon called electroporation (EP). Depending on the parameters of the electric current and cell features, electroporation can be either reversible or irreversible. The irreversible electroporation (IRE) found its use in urology as a non-thermal ablative method of prostate and renal cancer. As its mechanism is based on the permeabilization of cell membrane phospholipids, IRE (as well as other treatments based on EP) provides selectivity sparing extracellular proteins and matrix. Reversible EP enables the transfer of genes, drugs, and small exogenous proteins. In clinical practice, reversible EP can locally increase the uptake of cytotoxic drugs such as cisplatin and bleomycin. This approach is known as electrochemotherapy (ECT). Few in vivo and in vitro trials of ECT have been performed on urological cancers. EP provides the possibility of transmission of genes across the cell membrane. As the protocols of gene electrotransfer (GET) over the last few years have improved, EP has become a well-known technique for non-viral cell transfection. GET involves DNA transfection directly to the cancer or the host skin and muscle tissue. Among urological cancers, the GET of several plasmids encoding prostate cancer antigens has been investigated in clinical trials. This review brings into discussion the underlying mechanism of EP and an overview of the latest progress and development perspectives of EP-based treatments in urology.

Effect of upregulation of DD3 on early detection and prognosis in prostate cancer

BackgroundExpression of prostate cancer antigen 3 (PCA3 OR DD3) in the blood has been reported to be significantly higher in prostate cancer (PCa) than in benign prostate hyperplasia (BPH). To confirm whether DD3 expression is significantly different between PCa and BPH tissues, DD3 expression was tested in the blood both preoperatively and postoperatively and in the paired tissues of PCa patients.MethodsExpression levels of DD3 mRNA in the blood of patients who did not undergo surgery (PCa, n=102; BPH, n=53), those underwent surgery (preoperative, n=35; postoperative, n=35), and in PCa tissue specimens (tumor, n=41; adjacent normal, n=21) were determined by real-time quantitative PCR. Sensitivity and specificity for DD3 in PCa patients were validated by receiver operating characteristic (ROC) curve analysis.ResultsOur data suggest that expression level of DD3 in blood samples was significantly higher in PCa patients than in BPH patients (P=0.005). Expression of DD3 mRNA was also significantly elevated in PCa tissues compared with adjacent normal tissues (P=0.013). The increase in DD3 expression in PCa patients was further validated using a dataset from The Cancer Genome Atlas (n=549). Postoperative DD3 expression decreased following surgical intervention (P<0.001). Moreover, low DD3 expression was associated with improved overall survival (OS). Using gene set enrichment analysis, DD3 expression was correlated with specific PCa target genes including carcinogenesis-related and cancer proliferation-related genes.ConclusionsThis study demonstrated that expression of DD3 was upregulated in blood and PCa tumor tissues and was associated with prognosis. The oncogenic role of DD3 was further validated in the TCGA database, indicating that DD3 is a potential therapeutic target for PCa. Furthermore, this study suggests that DD3 expression could be considered as a prognostic biomarker for PCa.

Prostate cancer early diagnosis: circulating microRNA pairs potentially beyond single microRNAs upon 1231 serum samples.

The accuracy of prostate-specific antigen or clinical examination in prostate cancer (PCa) screening is in question, and circulating microRNAs (miRNAs) can be alternatives to PCa diagnosis. However, recent circulating miRNA biomarkers either are identified upon small sample sizes or cannot have robust diagnostic performance in every aspect of performance indicators. These may decrease applicability of potential biomarkers for the early detection of PCa. We reviewed recent studies on blood-derived miRNAs for prostate cancer diagnosis and carried out a large case study to understand whether circulating miRNA pairs, rather than single circulating miRNAs, could contribute to a more robust diagnostic model to significantly improve PCa diagnosis. We used 1231 high-throughput miRNA-profiled serum samples from two cohorts to design and verify a model based on class separability miRNA pairs (cs-miRPs). The pairwise model was composed of five circulating miRNAs coupled to miR-5100 and miR-1290 (i.e. five miRNA pairs, 5-cs-miRPs), reaching approximately 99% diagnostic performance in almost all indicators (sensitivity = 98.96%, specificity = 100%, accuracy = 99.17%, PPV = 100%, NPV = 96.15%) shown by a test set (n = 484: PCa = 384, negative prostate biopsies = 100). The nearly 99% diagnostic performance was also verified by an additional validation set (n = 140: PCa = 40, healthy controls = 100). Overall, the 5-cs-miRP model had 1 false positive and 7 false negatives among the 1231 serum samples and was superior to a recent 2-miRNA model (so far the best for PCa diagnosis) with 18 false positives and 80 false negatives. The present large case study demonstrated that circulating miRNA pairs could potentially bring more benefits to PCa early diagnosis for clinical practice.

The expression and functional analysis of the sialyl-T antigen in prostate cancer.

Aberrant glycosylation is a featured characteristic of cancer and plays a role in cancer pathology; thus an understanding of the compositions and functions of glycans is critical for discovering diagnostic biomarkers and therapeutic targets for cancer. In this study, we used MALDI-TOF-MS analysis to determine the O-glycan profiles of prostate cancer cells metastasized to bone (PC-3), brain (DU145), lymph node (LNCaP), and vertebra (VCaP) in comparison to immortalized RWPE-1 cells derived from normal prostatic tissue. Prostate cancer (CaP) cells exhibited an elevation of simple/short O-glycans, with a reduction of complex O-glycans, increased O-glycan sialylation and decreased fucosylation. Core 1 sialylation was increased dramatically in all CaP cells, and especially in PC-3 cells. The expression of Neu5Acα2-3Galβ1-3GalNAc- (sialyl-3T antigen) which is the product of α2,3-sialyltransferase-I (ST3Gal-I) was substantially increased. We therefore focused on exploring the possible function of ST3Gal-I in PC-3 cells. ST3Gal-I silencing studies showed that ST3Gal-I was associated with PC-3 cell proliferation, migration and apoptosis. Further in vivo studies demonstrated that down regulation of ST3Gal-I reduced the tumor size in xenograft mouse model, indicating that sialyl-3T can serve as a biomarker for metastatic prostate cancer prognosis, and that ST3Gal-I could be a target for therapeutic intervention in cancer treatment.

In Pursuit of Stability Enhancement of a Prostate Cancer Targeting Antibody Derived from a Transgenic Animal Platform

Accelerated timelines necessitate the discovery of fully human antibodies as biotherapeutics using transgenic animals with a notion that such mAbs bypass humanization. A transgenic animal derived mAb (PCa75) targeted against a prostate cancer antigen had several ‘unusual residues’ (rare somatic hypermutations, rSHM, with positional frequency of <1%) that resulted in compromised biophysical properties (Tm = 61 °C and intrinsic stability ΔGu = 24.3 kJ/mol) and a sub-optimal immunogenicity profile. In our quest for quality medicine, we pursued antibody engineering strategies to enhance the stability of PCa75. PCa62, an engineered variant of PCa75, retained function while significantly improving the drug-like attributes of the molecule (Tm = 75 °C and intrinsic stability ΔGu = 63.5 kJ/mol). rSHM is rather prevalent, 18 out the 21 approved transgenic animal-derived antibodies have at least one ‘unusual residue’. Thus, engineering of rSHM remains critical to enhance the stability and minimize immunogenicity risk of biotherapeutics.