Fluorescence self-assembled DNA hydrogel for the determination of prostate specific antigen by aggregation induced emission

In this study, an aptamer-based, functionalized-DNA hydrogel system is developed for prostate-specific antigen (PSA) detection. A pure DNA hydrogel is constructed using specific DNA building blocks and an aptamer as a cross-linker. Firstly, silver nanoclusters (AgNCs) are constructed on the Y-shaped DNA (Y-DNA) building blocks. Then, the DNA hydrogel was formed via the addition of the cross-linker to the Y-DNA solution. In this case, the fluorescence emission of silver nanoclusters that have accumulated in the hydrogel increases due to aggregation-induced emission (AIE). The presence of PSA and its subsequent interaction with its specific aptamer dissolve the hydrogel structures, which leads to a low emission intensity. A great linear relationship was attained in this assay in the range of 0.05 to 8 ng mL-1 with a detection limit of 4.4 pg mL-1 for the detection of PSA. Additionally, the proposed aptasensor was successfully used to detect PSA in human serum samples. The recovery for different concentrations of PSA was in the range of 96.1% to 99.3%, and the RSD range was from 2.3% to 4.5%. Comparing our method to current ones in the field of PSA detection proves that our platform benefits from a simpler procedure, lower cost, and better efficiency, providing high potential for future clinical applications.

Antifouling zwitterionic peptide hydrogel based electrochemical biosensor for reliable detection of prostate specific antigen in human serum

An electrochemical biosensor based on the antifouling zwitterionic peptide hydrogel (CFEFKFC) and the poly(3,4-ethylenedioxythiophene) (PEDOT) was fabricated to accurately detect prostate specific antigen (PSA) in complex human serum. The electrode was modified with the conducting polymer PEDOT and gold nanoparticles (AuNPs) in sequence through electrodeposition, and then the designed zwitterionic peptide hydrogel prepared through self-assembly was immobilized onto the modified electrode surface via the Au-S bond. The zwitterionic peptide hydrogel with cysteine terminal is easy for immobilization onto the gold surface, and it is also suitable for the immobilization of biomolecules such as PSA antibody in this work, through the formation of covalent amide bonds. The peptide hydrogel possessed excellent antifouling property, and it was able to effectively prevent the adsorption of nonspecific proteins, cells and other biomolecules. The developed antifouling biosensor showed a linear response range from 0.1 ng mL^-1 to 100 ng mL^-1, with a low limit of detection down to 5.6 pg mL^-1. These results encourage the wide use of zwitterionic peptide hydrogels as antifouling materials in various sensing and bio-sensing devices.

Induction of IDO1 and Kynurenine by Serine Proteases Subtilisin, Prostate Specific Antigen, CD26 and HtrA: A New Form of Immunosuppression?

Several serine proteases have been linked to autoimmune disorders and tumour initiation although the mechanisms are not fully understood. Activation of the kynurenine pathway enzyme indoleamine-2,3-dioxygenase (IDO1) modulates cellular activity in the brain, tolerogenesis in the immune system and is a major checkpoint in cancer development. We now report that IDO1 mRNA and IDO1 protein expression (generating kynurenine) are induced in human monocyte-derived macrophages by several chymotryptic serine proteases with direct links to tumorigenesis, including Prostate Specific Antigen (PSA), CD26 (Dipeptidyl-peptidase-4, CD26/DPP-4), High Temperature Requirement protein-A (HtrA), and the bacterial virulence factor subtilisin. These proteases also induce expression of the pro-inflammatory cytokine genes IL1B and IL6. Other serine proteases tested: bacterial glu-C endopeptidase and mammalian Pro-protein Convertase Subtilase-Kexin-3 (PCSK3, furin), urokinase plasminogen activator (uPA), cathepsin G or neutrophil elastase, did not induce IDO1, indicating that the reported effects are not a general property of all serine proteases. The results represent a novel mechanism of activating immunosuppressive IDO1 and inducing kynurenine generation which, together with the production of inflammatory cytokines, would contribute to tumour initiation and progression, providing a new target for drug development. In addition, the proteasomal S20 serine protease inhibitor carfilzomib, used in the treatment of myeloma, prevented the induction of IDO1 and cytokine gene expression, potentially contributing to its clinical anti-cancer activity.

Prostate Cancer From a Sex and Gender Perspective: A Review

INTRODUCTION

Factors influencing patient behavior regarding risk of prostate cancer (PCa) and outcomes of PCa treatments are poorly understood. Similarly, how PCa treatments affect patient sexual function and sense of their masculinity has not been fully investigated. A better understanding of the relationship between sex and gender for patients with PCa could significantly improve their care and quality of life.

OBJECTIVES

To review how concerns about sex and gender influence men's attitudes toward PCa screening, diagnosis, and treatment. To explore how PCa influences sexual function and self-perceived masculine identity. To examine contexts for PSA screening for transgender individuals.

METHODS

We reviewed biomedical and sociological literature exploring the impact of PCa on patient sexual function and self-perceived masculinity using OVID, PubMed, and other databases. We similarly reviewed how masculine gender norms influence patient willingness to engage with PCa screening, diagnoses, and treatment.

RESULTS

Gender norms and sexual function concerns influence patient engagement in all aspects of PCa care. This includes PSA screening, digital rectal examinations, active surveillance, and androgen deprivation therapy (ADT) amongst others. ADT is particularly challenging to sexual function, self-esteem, and masculine identity. Our research suggests that sex and gender are not separate concepts, but rather tightly intertwined, particularly when dealing with the realities experienced by patients with PCa.

CONCLUSION

Interventions to help patients deal with the challenges of PCa and its treatment are likely to be most effective if they concurrently address patients' sexual needs and understanding of gender norms. PSA screening should be considered for transgender individuals who are at greater risk of cancer and on long-term hormone therapy. More research is needed on how concerns over sex and gender influence PCa screening, diagnosis, and treatment. There is also a need for long term data on the oncological outcomes of prolonged exposure to hormone therapy for patients who are transgender. Muermann MM, Wassersug RJ. Prostate Cancer From a Sex and Gender Perspective: A Review. Sex Med Rev 2021;XX:XXX-XXX.

Undetectable PSA after radical prostatectomy is more likely in low burden N+ prostate cancer patients when an extended lymph node dissection is performed

OBJECTIVES

To analyze the likelihood of undetectable PSA (< 0.01 ng/mL) after extended (ePLND) versus standard pelvic lymph-nodes dissection (sPLND) in pN+ patients.

MATERIALS AND METHODS

The institutional prospectively maintained Prostate Cancer Database was queried for patients who underwent radical prostatectomy with PLND and were found with 3or less lymph-nodal metastases between 2007 and 2017. The extension of the PLND was defined according to the number of lymph-nodes (LN) removed. Patients in the 75th or higher percentile of lymph-nodes removed were considered as the ePLND group; patients in the 25th or lower percentile in the sPLND group. Groups were compared in clinical and pathological variables. Student T-test was used for comparing continuous variables; chi-square test was used for categorical variables. Multivariable logistic regression assessed the probability of undetectable PSA at 3^rd month postoperatively. Kaplan-Meier method estimated the probability of biochemical recurrence. Differences between the groups were compared by Log-rank test.

RESULTS

1478 patients were treated within the time span considered. 95 with 1 to 3 lymph-nodal metastases were extracted. After accounting for inclusion criteria, 23 patients with a median of 11 LN removed were included in the sPLND group (25th percentile); 23 patients with > 27 LN were included in ePLND group (75th percentile). Surgical time was longer for ePLND. Sixteen patients (69.6%) who underwent ePLND had undetectable PSA postoperatively. At multivariable analysis, the probability of undetectable PSA at 3^rd month was higher in patients who received an ePLND (HR=5.18; IC 95%=1.16-23.11; P=.03).

CONCLUSIONS

ePLND is more likely to predict undetectable PSA at third month after radical prostatectomy, irrespective of disease characteristics.

Prostate Cancer Screening Trends After United States Preventative Services Task Force Guidelines in an Underserved Population

Purpose: Prostate cancer screening is a controversial topic. We examined trends in Prostate Specific Antigen (PSA) testing in an underserved population before and after the United States Preventative Services Task Force (USPSTF) recommendation against screening.

Methods: Data were collected on all PSA and cholesterol screening tests from 2008 to 2014. We examined the trend of these tests and prostate biopsies while comparing this data to lipid panel data to adjust for changes in patient population.

Results: A decrease in PSA screening was observed from 2010 through 2014, with the greatest decline in 2012. The age group most affected was patients aged 55–69 years. The amount of prostate biopsies during this period decreased as well.

Conclusions: Decreased rates of PSA screening were observed in our urban hospital population that preceded the publication of the USPSTF guidelines. The incidence of prostate biopsies decreased in this timeframe. It now remains to be demonstrated whether decreased PSA screening rates impact the diagnosis of and ultimately the survival from prostate cancer.

The Advantages of Transurethral Resection of the Prostate in Patients with an Elevated or Rising Prostate Specific Antigen, Mild or Moderate Lower Urinary Tract Symptoms, Bladder Outlet Obstruction and Negative Prostate Cancer Imaging or Prostate Biopsies: A Prospective Analysis in 105 Consecutive Patients

OBJECTIVE

To investigate elevated or rising prostate specific antigen (PSA) as a marker for bladder outlet obstruction (BOO) in patients with minor lower urinary tract symptoms (LUTS) and without prostate cancer.

MATERIALS AND METHODS

One hundred and five consecutive patients were prospectively analyzed between 2005 and 2013. All patients were referred to the principal investigator by their general practitioner as a result of an elevated and/or rising PSA. Only patients with minor LUTS [International Prostate Symptom Score (I-PSS) 0-19] and without suspicion for prostate cancer were included. All patients had BOO, shown by full urodynamics, and underwent transurethral resection of the prostate. The resected tissue was histologically examined and PSA and I-PSS were evaluated after 3, 6 and 12 months and later on yearly.

RESULTS

Mean pre-operative PSA and I-PSS values were 8.8 ng/ml and 11.1, respectively. The mean detrusor pressure at maximum flow was 93.6 cmH₂O. The mean resected volume was 52 g and the mean prostate biopsy rate was 1.8. Eighty-three of 105 patients (79%) had no malignancy and were diagnosed with BOO due to benign prostate hyperplasia (subgroup 1). Their mean PSA decreased from 9.2 to 0.7 ng/ml and 0.9 ng/ml after 6 and 12 months post-operation, respectively. The mean I-PSS declined from 11 to 3 after 6 and 12 months. Sixteen of 105 patients (15%) were treated for prostate cancer (subgroup 2). Radical prostatectomy was performed in 11 patients, brachytherapy in 3 patients and external beam radiotherapy in 2 patients. Six of 105 patients (5.7%) had active surveillance (subgroup 3).

CONCLUSION

BOO can cause an elevated or rising PSA in patients with minor LUTS and negative screening for prostate cancer. Transurethral resection of the prostate is an adequate treatment for these patients.

Sensitive prostate specific antigen quantification using dihydrolipoic acid surface-functionalized phosphorescent quantum dots

Herein, high-quality Mn-doped ZnS quantum dots (QDs) have been synthesized using a facile approach directly in aqueous media. The surface of the obtained QDs was further modified by cap-exchange of the native cysteine shell with dihydrolipoic acid (DHLA) ligands resulting in nanocrystals with high water-stability having an intense phosphorescent signal. Covalent bioconjugation of the DHLA-coated nanoparticles with an anti-IgG antibody was then carried out. Interestingly the QD immunoprobe (QD-labelled antibodies) maintained an intense phosphorescence emission, without any significant spectral-shift (as compared to the free QDs). Coupling of an asymmetric flow field flow fractionation technique to an elemental mass spectrometry detection enabled the accurate determination of the efficiency of the bioconjugation reaction. The obtained nanoparticle-antibody bioconjugate was then applied to develop a quantitative sandwich-type phosphorescent immunoassay for Prostate Specific Antigen (PSA), and a limit of detection (LOD) of 17 pg mL^-1 of PSA was achieved and allow to quantify such biomarker in samples within clinically relevant levels. Finally, the assay was validated for the quantification of PSA in the cellular media of prostate cancer cells. Obtained results proved the robustness of the proposed immunoassay based on long-lived phosphorescence measurements against eventual photoluminescent interferences significantly affecting the conventional short-lived fluorescence detection.

Prostate-based biofluids for the detection of prostate cancer: A comparative study of the diagnostic performance of cell-sourced RNA biomarkers

BACKGROUND

Prostate cancer (PCa) diagnosis requires improvement with the aid of more accurate biomarkers. Postejaculate urethral washings (PEUW) could be a physiological equivalent to urine obtained following rectal prostatic massage, the current basis for the prostate cancer antigen 3 (PCA3) test. The aim of this study was to investigate if PEUW contained prostate-based material, evidenced by the presence of prostate specific antigen (PSA), and to evaluate the diagnostic performance of PEUW-based biomarkers.

METHODS

Male patients referred for elevated serum PSA or abnormal digital rectal examination provided ejaculate and PEUW samples. PSA, PCA3, and β2-microglobulin (β2M) were quantified in ejaculate and PEUW and compared with absolute and clinically significant (according to D'Amico criteria) PCa presence, as determined by biopsies. Diagnostic performance was determined and compared with serum PSA using receiver operating characteristic analysis.

RESULTS

From 83 patients who provided PEUW samples, paired analysis with ejaculate samples was possible for 38 patients, while analysis in an unpaired, extended cohort was possible for 62 patients. PSA and PCA3 were detected in PEUW, normalized to β2M, and PCA3:PSA was calculated. In predicting absolute PCa status, PCA3:β2M in ejaculate [area under the curve (AUC) 0.717] and PEUW (AUC 0.569) were insignificantly better than PCA3:PSA (AUC 0.668 and 0.431, respectively) and comparable with serum PSA (AUC 0.617) with similar trends observed for the extended cohort. When considering clinically significant PCa presence, serum PSA in the comparison (AUC 0.640) and extended cohorts (AUC 0.665) was comparable with PCA3: β2M (AUC 0.667) and PCA3:PSA (AUC 0.605) in ejaculate, with lower estimates for PEUW in the comparison (PCA3: β2M AUC 0.496; PCA3:PSA AUC 0.342) and extended (PCA3: β2M AUC 0.497; PCA3:PSA AUC 0.469) cohorts. The statistical analysis was limited by sample size.

CONCLUSION

PEUW contains prostatic material, but has limited diagnostic accuracy when considering cell-derived DNA analysis. PCA3-based markers in ejaculate are comparable to serum PSA and digital rectal examination-urine markers.

Evolution of the patient characteristics of candidates for radical prostatectomy and the results obtained with the technique

OBJECTIVES

To evaluate the oncological profile and risk of biochemical recurrence of patients with prostate cancer who underwent radical prostatectomy based on the time period in which the patients were operated. To evaluate the differences in prostate-specific antigen (PSA) at diagnosis of patients with or without biochemical recurrence based on these time periods.

MATERIAL AND METHODS

Observation carried forward study of a cohort of 972 radical prostatectomies performed during 3 time periods (1994-2000, 2001-2006, 2007-2011). The importance of PSA at diagnosis on the time periods and on biochemical recurrence was assessed using a generalized linear model. The independent predictive behavior of biochemical recurrence was analyzed using Cox regression.

RESULTS

The median follow-up was 38 (16-76) months. PSA levels at diagnosis were higher in the period 1994-2000 (12.97ng/mL, P<.001). Seventy-two percent of the patients from the period 2007-2011 were diagnosed as clinical stage T1c (P<.001), compared with 55% from the period 1994-2000. The percentage of extracapsular extension in the specimen decreased from 27% to 18% from the period 1994-2000 to the period 2007-2011 (p<.001). The percentage of patients with biochemical recurrence went from 38% to 14% from the first to the third period (P>.001). The difference between PSA levels at diagnosis for the patients with or without biochemical recurrence was independent of the period (P=.84). The period during which surgery was performed was not an independent predictive factor for biochemical recurrence (P=.09).

CONCLUSIONS

Patients from the 2007-2011 period had less extracapsular disease in the radical prostatectomy. The period was not an independent predictive factor for biochemical recurrence.

The efficiency of the serum prostate specific antigen levels in diagnosing prostatic enlargements

BACKGROUND

The objective of this study was to evaluate the serum PSA levels in patients presenting with enlarged prostate and to evaluate the efficiency of serum PSA to diagnose and differentiate benign and malignant enlargements.

METHODS

The authors evaluated the patients coming in surgical OPD with enlarged prostate and were advised to undergo serum PSA testing.

RESULTS

The efficiency of serum PSA to differentiate Benign and malignant lesions was 97.18% and 83.33% respectively.