Biomarkers in prostate cancer: new era and prospective

Elevated PSPC1 and KDM5C expression indicates poor prognosis in prostate cancer

Prostate cancer (PCa) remains the most commonly diagnosed cancer in men worldwide and is still the second leading cause of cancer-related death. One major cause of PCa development is epigenetic aberration, including histone modification. We have previously demonstrated that Lysine Demethylase 5C (KDM5C) plays an essential role in the development of PCa and drives PCa progression by promoting epithelial-mesenchymal transition. Epigenetic regulators often work in concert, for example, to regulate transcription. We identified Paraspeckle Component 1 (PSPC1) as an interacting protein of KDM5C, suggesting that these proteins might function together in PCa. Here, we systematically investigate the expression patterns of KDM5C and PSPC1 in 2 independent prostate cohorts (432 and 205 prostate tumors in total for PSPC1 and KDM5C, respectively) by immunohistochemistry. We demonstrate that the expression of PSPC1 correlates with that of KDM5C. In addition, PSPC1 is up-regulated in primary and metastatic PCa. Elevated PSPC1 expression correlates with a higher-grade group and an advanced T-stage. Patients with high PSPC1 expression have a worse biochemical recurrence-free survival. In addition, PSPC1 expression is an independent prognostic parameter. Our data indicate that KDM5C and PSPC1 are involved in PCa progression, and therapeutic inhibition of KDM5C and PSPC1 by selective compounds might be a promising approach for the treatment of PCa.

Multiplexed Prostate Cancer Companion Diagnostic Devices

Prostate cancer (PCa) remains one of the most prominent forms of cancer for men. Since the early 1990s, Prostate-Specific Antigen (PSA) has been a commonly recognized PCa-associated protein biomarker. However, PSA testing has been shown to lack in specificity and sensitivity when needed to diagnose, monitor and/or treat PCa patients successfully. One enhancement could include the simultaneous detection of multiple PCa-associated protein biomarkers alongside PSA, also known as multiplexing. If conventional methods such as the enzyme-linked immunosorbent assay (ELISA) are used, multiplexed detection of such protein biomarkers can result in an increase in the required sample volume, in the complexity of the analytical procedures, and in adding to the cost. Using companion diagnostic devices such as biosensors, which can be portable and cost-effective with multiplexing capacities, may address these limitations. This review explores recent research for multiplexed PCa protein biomarker detection using optical and electrochemical biosensor platforms. Some of the novel and potential serum-based PCa protein biomarkers will be discussed in this review. In addition, this review discusses the importance of converting research protocols into multiplex point-of-care testing (xPOCT) devices to be used in near-patient settings, providing a more personalized approach to PCa patients’ diagnostic, surveillance and treatment management.

Urinary microRNA-1913 to microRNA-3659 expression ratio as a non-invasive diagnostic biomarker for prostate cancer

PURPOSE

MicroRNAs (miRNAs) are small non-coding RNAs and are involved in the development, proliferation, and pathogenesis of prostate cancer (PCa). Urinary miRNAs are promising non-invasive biomarkers for PCa diagnosis because of their stability in urine. Here, we evaluated the diagnostic value of urinary miR-1913 to miR-3659 ratio in PCa patients and benign prostate hyperplasia (BPH) controls.

MATERIALS AND METHODS

Candidate miRNAs were identified from urinary microarray data and tested by real-time PCR. The urinary miR-1913 to miR-3659 expression ratio was selected and tested in 83 urine samples (44 PCa and 39 BPH) to confirm its validity as a non-invasive diagnostic biomarker for PCa.

RESULTS

The expression ratio of urinary miR-1913 to miR-3659 was significantly higher in PCa than in BPH (p=0.002) and showed a higher area under the receiver operating characteristic curve than prostate-specific antigen (PSA; 0.821 vs. 0.518) in patients within the PSA gray zone (tPSA: 3-10 ng/mL), with sensitivity of 75.0% and specificity of 78.6% (p=0.003).

CONCLUSIONS

The urinary miR-1913 to miR-3659 expression ratio was increased in PCa and may serve as a useful supplemental biomarker to PSA for the diagnosis of PCa, particularly in patients within the PSA gray zone.

Impact of cyclin D1 and DJ-1 on diagnosis, clinico-pathological features and outcome in prostate cancer and benign prostatic hyperplasia

Background

Disturbance in cell cycle regulatory genes is a common finding among many types of cancers. The aim of this study is to evaluate the role of cyclin D1 and DJ-1 in benign prostatic hyperplasia (BPH) and prostate cancer (PC).

Method

The current study enclosed 40 patients diagnosed with PC and 40 cases of BPH. The expression level of cyclin D1 and DJ-1 were evaluated by immunohistochemistry (IHC). Cyclin D1 scored depending on the percentage of stained nuclear tumor cells. While scoring of DJ-1 was based on intensity. The results were correlated with clinicopathological features and outcome.

Results

In the PC group, cyclin D1 was detected in 95% and overexpressed in 42.5%, DJ-1 was positively stained in 85% and overexpressed in 47.5%. Meanwhile, in the BPH group, cyclin D1 was not detected and DJ-1 stained in only 2.5%. There was a statistically significant difference in Gleason score (GS), tumor stage, size, and treatment failure (p =< 0.001). In the terms of PC diagnosis prediction, although cyclin D1 was more specific (100%), DJ-1 is more sensitive than cyclin D1 (80%, 70%, respectively) (p = 0.000).

Conclusions

Cyclin D1 and DJ-1 may emerge as a promising way for diagnosis of PC in certain circumstances, as the presence of insufficient tissue sampling, small foci of carcinoma or benign lesions mimic PC. This is in addition to the known role of cyclin D1 and DJ-1 in PC prognosis.

The use of serum zinc to prostate-specific antigen ratio as a biomarker in the prediction of prostate biopsy outcomes

AIM

To generate a combination of serum zinc (Zn) and prostate-specific antigen (PSA) in an attempt to provide better prediction of prostate biopsy outcomes with Zn/PSA ratios.

MATERIALS & METHODS

Diagnostic performances of PSA and Zn/PSA were investigated using receiver operating characteristic and the area under the curve analysis and McNemar test in 480 men. Decision curve analysis was also used to determine the net clinical benefits of the two parameters.

RESULTS

The receiver operating characteristic-area under the curve analysis established a similar diagnostic performance for both parameters. Although Zn/PSA had a higher diagnostic sensitivity, PSA was superior in terms of specificity and net clinical benefits.

CONCLUSION

Zn/PSA has no substantial superiority in the prediction of prostate biopsy outcomes.

Specific and reliable detection of Myosin 1C isoform A by RTqPCR in prostate cancer cells

Background

Prostate cancer (PC) diagnostics and treatment often present a challenging task due to cancer subtype heterogeneity and differential disease progression in patient subgroups. Hence, the critical issue is finding a reliable and sensitive diagnostic and prognostic PC marker, especially for cases of biopsies with low percentages of cancer cells. Isoform A of myosin 1C was shown to be expressed in PC cells and responsible for their invasive properties, however, its feasibility for diagnostic purposes remains to be elucidated.

Methods

To verify the role of myosin 1C isoform A mRNA expression as a putative prostate cancer marker we performed RT qPCR normalized by three reference genes (GAPDH, YWHAZ, HPRT1) on PC3, RWPE-1, LNCaP and 22Rv1 cell lines. Myosin 1C isoform A detection specificity was confirmed by immunofluorescence staining, cancer and non-cancer prostate cell lines were immunophenotyped by flow cytometry.

Results

Median normalized mRNA expression level of myosin 1C isoform A in PC cells (PC3 and 22Rv1) is two orders of magnitude higher compared to RWPE-1 cells, which functionally correspond to benign prostate cells. Myosin 1C isoform A expression allows PC cell detection even at a dilution ratio of 1:1000 cancer to non-cancer cells. At the protein level, the mean fluorescence intensity of myosin 1C isoform A staining in PC3 nuclei was only twice as high as in RWPE-1, while the immunophenotypes of both cell lines were similar (CD44+/CD90-/CD133-/CD57-/CD24+-).

Conclusions

We report a distinct difference in myosin 1C isoform A mRNA levels in malignant (PC3) and benign (RWPE-1) prostate cell lines and suggest a combination of three reference genes for accurate data normalization. For the first time we provide an immunophenotype comparison of RWPE-1 and PC3 cells and demonstrate that RT qPCR analysis of MYO 1C A using appropriate reference genes is sufficient for PC detection even in low-abundance cancer specimens.

Retrospective Study of the Significant Predictive Role of Inflammatory Degree in Initial and Repeat Prostate Biopsy Specimens for Detecting Prostate Cancer

Purpose

The purpose of this study was to determine whether histologic inflammation (HI) in initial and repeat prostate biopsy specimens was significantly associated with the detection of prostate cancer.

Materials and Methods

Between 2005 and 2017, the clinicopathological records of patients with high prostatespecific antigen (PSA) levels who underwent initial and repeat prostate biopsies were retrospectively reviewed. The presence of HI and its degree in each biopsied specimen were interpreted by one uropathologist with 20 years of experience. The association between HI and cancer diagnosis was statistically assessed, with p < 0.05 considered significant, and the cancer and non-cancer groups were compared.

Results

Among the 522 patients with a median PSA levels of 6.5 ng/dL, including 258 (49.4%) whose cancer was diagnosed following repeat biopsy, the median degrees of HI in the initial and repeat biopsies were 25.0% and 41.7%, respectively. Furthermore, 211 (40.4%) and 247 (47.3%) patients had HI (> 0%) on biopsied specimens, respectively. Comparison of the cancer and noncancer groups revealed that a greater rate of HI specimens in the initial biopsy was associated with fewer prostate cancer diagnoses following repeat biopsy (p < 0.001). Other comparisons between the cancer and non-cancer groups showed that the cancer group had a significantly higher rate of hypertension, whereas those non-cancer group had a significantly higher rate of benign prostatic hyperplasia and prostatitis (p < 0.05).

Conclusion

A finding of a lesser degree of HI in the initial and a greater degree of HI in the repeat biopsied specimens was associated with the higher probability of cancer diagnosis in patients with high PSA levels.

Focal Ablation of Prostate Cancer

The challenge to the urology community is to reduce the risks of screening and treatment by reducing the number of men undergoing unnecessary biopsy and whole-gland curative treatment of low-risk disease. There is compelling evidence that focal ablation of prostate cancer is truly minimally invasive and offers major functional advantages over whole-gland treatment.

Full-length antibodies versus single-chain antibody fragments for a selective impedimetric lectin-based glycoprofiling of prostate specific antigen

The main aim of the research was to design a functional impedimetric biosensor able to glycoprofile prostate specific antigen (PSA), a biomarker for prostate cancer (PCa), with high specificity using lectins as glycan recognising proteins. Traditionally, full-length antibody is immobilised on the biosensor interface for specific capture of PSA with subsequent glycoprofiling of PSA by addition of lectins. Since full-length antibodies contain glycans in the Fc domain, particular attention has to be paid to suppress direct binding of lectins to immobilised full-length antibodies, which would compromise accurate glycoprofiling. This issue is addressed here using a recombinant single-chain antibody fragments (scAb), which do not contain any carbohydrate moiety. Surface plasmon resonance was applied to prove negligible interaction of lectins with immobilised scAb fragments, while substantial binding of lectins to full length antibodies was observed. Eight different biosensor designs were tested for their ability to detect PSA. The biosensor device based on scAb fragments covalently immobilised on the gold electrode surface, patterned by a mixed SAM using standard amine coupling chemistry, proved to be the most sensitive. The scAb fragment-based biosensor exhibited sensitivity of 15.9 ± 0.8% decade^-1 (R² = 0.991 with an average RSD of 4.9%), while the full antibody-based biosensor offered sensitivity towards PSA of 4.2 ± 0.1% decade^-1 (R² = 0.999 with an average RSD of 4.8%). Moreover, the selectivity of the scAb-based biosensor was tested using a kallikrein 2 protein, a protein structurally similar to PSA, and the results indicated high selectivity for PSA detection.

Comparative Study of Blood-Based Biomarkers, α2,3-Sialic Acid PSA and PHI, for High-Risk Prostate Cancer Detection

Prostate Specific Antigen (PSA) is the most commonly used serum marker for prostate cancer (PCa), although it is not specific and sensitive enough to allow the differential diagnosis of the more aggressive tumors. For that, new diagnostic methods are being developed, such as PCA-3, PSA isoforms that have resulted in the 4K score or the Prostate Health Index (PHI), and PSA glycoforms. In the present study, we have compared the PHI with our recently developed PSA glycoform assay, based on the determination of the α2,3-sialic acid percentage of serum PSA (% α2,3-SA), in a cohort of 79 patients, which include 50 PCa of different grades and 29 benign prostate hyperplasia (BPH) patients. The % α2,3-SA could distinguish high-risk PCa patients from the rest of patients better than the PHI (area under the curve (AUC) of 0.971 vs. 0.840), although the PHI correlated better with the Gleason score than the % α2,3-SA. The combination of both markers increased the AUC up to 0.985 resulting in 100% sensitivity and 94.7% specificity to differentiate high-risk PCa from the other low and intermediate-risk PCa and BPH patients. These results suggest that both serum markers complement each other and offer an improved diagnostic tool to identify high-risk PCa, which is an important requirement for guiding treatment decisions.

LINE-1 methylation status in prostate cancer and non-neoplastic tissue adjacent to tumor in association with mortality

Aberrant DNA methylation seems to be associated with prostate cancer behavior. We investigated LINE-1 methylation in prostate cancer and non-neoplastic tissue adjacent to tumor (NTAT) in association with mortality from prostate cancer. We selected 157 prostate cancer patients with available NTAT from 2 cohorts of patients diagnosed between 1982-1988 and 1993-1996, followed up until 2010. An association between LINE-1 hypomethylation and prostate cancer mortality in tumor was suggested [hazard ratio per 5% decrease in LINE-1 methylation levels: 1.40, 95% confidence interval (CI): 0.95-2.01]. After stratification of the patients for Gleason score, the association was present only for those with a Gleason score of at least 8. Among these, low (<75%) vs. high (>80%) LINE-1 methylation was associated with a hazard ratio of 4.68 (95% CI: 1.03-21.34). LINE-1 methylation in the NTAT was not associated with prostate cancer mortality. Our results are consistent with the hypothesis that tumor tissue global hypomethylation may be a late event in prostate cancerogenesis and is associated with tumor progression.

Biomarkers for evaluation of prostate cancer prognosis

Prostate cancer, with a lifetime prevalence of one in six men, is the second cause of malignancy-related death and the most prevalent cancer in men in many countries. Nowadays, prostate cancer diagnosis is often based on the use of biomarkers, especially prostate-specific antigen (PSA) which can result in enhanced detection at earlier stage and decreasing in the number of metastatic patients. However, because of the low specificity of PSA, unnecessary biopsies and mistaken diagnoses frequently occur. Prostate cancer has various features so prognosis following diagnosis is greatly variable. There is a requirement for new prognostic biomarkers, particularly to differentiate between inactive and aggressive forms of disease, to improve clinical management of prostate cancer. Research continues into finding additional markers that may allow this goal to be attained. We here selected a group of candidate biomarkers including PSA, PSA velocity, percentage free PSA, TGFβ1, AMACR, chromogranin A, IL-6, IGFBPs, PSCA, biomarkers related to cell cycle regulation, apoptosis, PTEN, androgen receptor, cellular adhesion and angiogenesis, and also prognostic biomarkers with Genomic tests for discussion. This provides an outline of biomarkers that are presently of prognostic interest in prostate cancer investigation.

Alternatively activated macrophages are associated with metastasis and poor prognosis in prostate adenocarcinoma

Recent studies have revealed that alternatively activated macrophages (AAMs) are involved in tumor progression. However, the effect of AAMs on the metastasis of prostate cancer is poorly understood. In the present study, the prostate tissues of 42 patients with prostate adenocarcinoma (PCa) were used in the analysis of tumor associated macrophages (TAMs) and AAMs by immunofluorescence. The patients were followed up for 5 years. The associations of TAMs and AAMs with the clinicopathological features and outcome in these cases were evaluated. Immunofluorescent analysis indicated that the mean number of TAMs (CD68-positive cells) in the prostate tissues of PCa patients with metastasis [45.29±7.25 cells/high-power field (HPF)] was significantly higher compared with that of PCa patients without metastasis (33.57±5.25 cells/HPF; P<0.01). The mean numbers of AAMs (CD68- and CD206-positive cells) in the tissues of PCa patients with and without metastasis were 29.43±5.68 and 9.14±5.29 cells/HPF, respectively. In addition, the percentage of AAMs (number of AAMs/number of TAMs) was 65.11±9.68 and 27.32±7.85% in patients with and without metastasis, respectively. The differences in the number and percentage of AAMs between the two groups were statistically significant (P<0.01). The number and percentage of AAMs was positively correlated with tumor grade and serum prostate-specific antigen (PSA) level. Univariate analysis indicated that the level of PSA, Gleason score, metastatic status, T grade, number of TAMs, number of AAMs and percentage of AAMs were predictors of the overall survival. Furthermore, multivariate analyses revealed that Gleason score, level of PSA and number of TAMs were predictors for overall survival rate. These results indicate that TAMs and AAMs may be important in the metastasis of PCa, and that TAMs and AAMs may be used as potential biomarkers of poor prognosis in late-stage PCa patients.

Glycogen synthase kinase-3: a potential preventive target for prostate cancer management

OBJECTIVES

Prostate cancers are the frequently diagnosed cancers in men, and patients with metastatic disease only have 28% chance for 5-year survival. Patients with low-risk tumors are subjected to active surveillance, whereas high-risk cases are actively treated. Unfortunately, there is no cure for patients with late-stage disease. Glycogen synthase kinase-3 (GSK-3, α and β) is a protein serine/threonine kinase and has diverse cellular functions and numerous substrates. We sought to summarize all the studies done with GSK-3 in prostate cancers and to provide a prospective direction for future work.

METHODS AND MATERIALS

A comprehensive search of the literature on the electronic databases PubMed was conducted for the subject terms of GSK-3 and prostate cancer. Gene mutation and expression information was extracted from Oncomine and COSMIC databases. Case reports were not included.

RESULTS

Accumulating evidence indicates that GSK-3α is mainly expressed in low-risk prostate cancers and is related to hormone-dependent androgen receptor (AR)-mediated gene expression, whereas GSK-3β is mainly expressed in high-risk prostate cancers and is related to hormone-independent AR-mediated gene expression. GSK-3 has been demonstrated as a positive regulator in AR transactivation and prostate cancer growth independent of the Wnt/β-catenin pathway. Different types of GSK-3inhibitors including lithium show promising results in suppressing tumor growth in different animal models of prostate cancer. Importantly, clinical use of lithium is associated with reduced cancer incidence in psychiatric patients.

CONCLUSIONS

Taken together, GSK-3 inhibition might be implicated in prostate cancer management as a preventive treatment.