Protocadherin-17 promoter methylation in serum-derived DNA is associated with poor prognosis of bladder cancer

Epigenetic changes associated with Bacillus Calmette-Guerin (BCG) treatment in bladder cancer

Bacillus Calmette-Guérin (BCG) treatment for non-muscle invasive bladder cancer (NMIBC) is an established immunotherapeutic, however, a significant portion of patients do not respond to treatment. Despite extensive research into the therapeutic mechanism of BCG, gaps remain in our understanding. This review specifically focuses on the epigenomic contributions in the immune microenvironment, in the context of BCG treatment for NMIBC. We also summarise the current understanding of NMIBC epigenetic characteristics, and discuss how future targeted strategies for BCG therapy should incorporate epigenomic biomarkers in conjunction with genomic biomarkers.

Liquid biopsy in urothelial carcinoma: Detection techniques and clinical applications

The types of urothelial carcinoma (UC) include urothelial bladder cancer and upper tract urothelial carcinoma. Current diagnostic techniques cannot meet the needs of patients. Liquid biopsy is an accurate method of determining the molecular profile of UC and is a cutting-edge and popular technique that is expected to complement existing detection techniques and benefit patients with UC. Circulating tumor cells, cell-free DNA, cell-free RNA, extracellular vesicles, proteins, and metabolites can be found in the blood, urine, or other bodily fluids and are examined during liquid biopsies. This article focuses on the components of liquid biopsies and their clinical applications in UC. Liquid biopsies have tremendous potential in multiple aspects of precision oncology, from early diagnosis and treatment monitoring to predicting prognoses. They may therefore play an important role in the management of UC and precision medicine.

Hypermethylation-Mediated Silencing of CIDEA, MAL and PCDH17 Tumour Suppressor Genes in Canine DLBCL: From Multi-Omics Analyses to Mechanistic Studies

Gene expression is controlled by epigenetic deregulation, a hallmark of cancer. The DNA methylome of canine diffuse large B-cell lymphoma (cDLBCL), the most frequent malignancy of B-lymphocytes in dog, has recently been investigated, suggesting that aberrant hypermethylation of CpG loci is associated with gene silencing. Here, we used a multi-omics approach (DNA methylome, transcriptome and copy number variations) combined with functional in vitro assays, to identify putative tumour suppressor genes subjected to DNA methylation in cDLBCL. Using four cDLBCL primary cell cultures and CLBL-1 cells, we found that CiDEA, MAL and PCDH17, which were significantly suppressed in DLBCL samples, were hypermethylated and also responsive (at the DNA, mRNA and protein level) to pharmacological unmasking with hypomethylating drugs and histone deacetylase inhibitors. The regulatory mechanism underneath the methylation-dependent inhibition of those target genes expression was then investigated through luciferase and in vitro methylation assays. In the most responsive CpG-rich regions, an in silico analysis allowed the prediction of putative transcription factor binding sites influenced by DNA methylation. Interestingly, regulatory elements for AP2, MZF1, NF-kB, PAX5 and SP1 were commonly identified in all three genes. This study provides a foundation for characterisation and experimental validation of novel epigenetically-dysregulated pathways in cDLBCL.

A Novel CpG Methylation Risk Indicator for Predicting Prognosis in Bladder Cancer

Purpose

Bladder cancer (BLCA) is one of the most common cancers worldwide. In a large proportion of BLCA patients, disease recurs and/or progress after resection, which remains a major clinical issue in BLCA management. Therefore, it is vital to identify prognostic biomarkers for treatment stratification. We investigated the efficiency of CpG methylation for the potential to be a prognostic biomarker for patients with BLCA.

Patients and Methods

Overall, 357 BLCA patients from The Cancer Genome Atlas (TCGA) were randomly separated into the training and internal validation cohorts. Least absolute shrinkage and selector operation (LASSO) and support vector machine-recursive feature elimination (SVM-RFE) were used to select candidate CpGs and build the methylation risk score model, which was validated for its prognostic value in the validation cohort by Kaplan–Meier analysis. Hazard curves were generated to reveal the risk nodes throughout the follow-up. Gene Set Enrichment Analysis (GSEA) was used to reveal the potential biological pathways associated with the methylation model. Quantitative real-time polymerase chain reaction (PCR) and western blotting were performed to verify the expression level of the methylated genes.

Results

After incorporating the CpGs obtained by the two algorithms, CpG methylation of eight genes corresponding to TNFAIP8L3, KRTDAP, APC, ZC3H3, COL9A2, SLCO4A1, POU3F3, and ADARB2 were prominent candidate predictors in establishing a methylation risk score for BLCA (MRSB), which was used to divide the patients into high- and low-risk progression groups (p < 0.001). The effectiveness of the MRSB was validated in the internal cohort (p < 0.001). In the MRSB high-risk group, the hazard curve exhibited an initial wide, high peak within 10 months after treatment, whereas some gentle peaks around 2 years were noted. Furthermore, a nomogram comprising MRSB, age, sex, and tumor clinical stage was developed to predict the individual progression risk, and it performed well. Survival analysis implicated the effectiveness of MRSB, which remains significant in all the subgroup analysis based on the clinical features. A functional analysis of MRSB and the corresponding genes revealed potential pathways affecting tumor progression. Validation of quantitative real-time PCR and western blotting revealed that TNFAIP8L3 was upregulated in the BLCA tissues.

Conclusion

We developed the MRSB, an eight-gene-based methylation signature, which has great potential to be used to predict the post-surgery progression risk of BLCA.

Identification of a four-gene methylation biomarker panel in high-grade serous ovarian carcinoma

Background The lack of effective biomarkers for the screening and early detection of ovarian cancer (OC) is one of the most pressing problems in oncogynecology. Because epigenetic alterations occur early in the cancer development, they provide great potential to serve as such biomarkers. In our study, we investigated a potential of a four-gene methylation panel (including CDH13, HNF1B, PCDH17 and GATA4 genes) for the early detection of high-grade serous ovarian carcinoma (HGSOC). Methods For methylation detection we used methylation sensitive high-resolution melting analysis and real-time methylation specific analysis. We also investigated the relation between gene hypermethylation and gene relative expression using the 2-ΔΔCt method. Results The sensitivity of the examined panel reached 88.5%. We were able to detect methylation in 85.7% (12/14) of early stage tumors and in 89.4% (42/47) of late stage tumors. The total efficiency of the panel was 94.4% and negative predictive value reached 90.0%. The specificity and positive predictive value achieved 100% rates. Our results showed lower gene expression in the tumor samples in comparison to control samples. The more pronounced downregulation was measured in the group of samples with detected methylation. Conclusions In our study we designed the four-gene panel for HGSOC detection in ovarian tissue with 100% specificity and sensitivity of 88.5%. The next challenge is translation of the findings to the less invasive source for biomarker examination, such as plasma. Our results indicate that combination of examined genes deserve consideration for further testing in clinical molecular diagnosis of HGSOC.

Cancer Epigenetic Biomarkers in Liquid Biopsy for High Incidence Malignancies

Early alterations in cancer include the deregulation of epigenetic events such as changes in DNA methylation and abnormal levels of non-coding (nc)RNAs. Although these changes can be identified in tumors, alternative sources of samples may offer advantages over tissue biopsies. Because tumors shed DNA, RNA, and proteins, biological fluids containing these molecules can accurately reflect alterations found in cancer cells, not only coming from the primary tumor, but also from metastasis and from the tumor microenvironment (TME). Depending on the type of cancer, biological fluids encompass blood, urine, cerebrospinal fluid, and saliva, among others. Such samples are named with the general term "liquid biopsy" (LB). With the advent of ultrasensitive technologies during the last decade, the identification of actionable genetic alterations (i.e., mutations) in LB is a common practice to decide whether or not targeted therapy should be applied. Likewise, the analysis of global or specific epigenetic alterations may also be important as biomarkers for diagnosis, prognosis, and even for cancer drug response. Several commercial kits that assess the DNA promoter methylation of single genes or gene sets are available, with some of them being tested as biomarkers for diagnosis in clinical trials. From the tumors with highest incidence, we can stress the relevance of DNA methylation changes in the following genes found in LB: SHOX2 (for lung cancer); RASSF1A, RARB2, and GSTP1 (for lung, breast, genitourinary and colon cancers); and SEPT9 (for colon cancer). Moreover, multi-cancer high-throughput methylation-based tests are now commercially available. Increased levels of the microRNA miR21 and several miRNA- and long ncRNA-signatures can also be indicative biomarkers in LB. Therefore, epigenetic biomarkers are attractive and may have a clinical value in cancer. Nonetheless, validation, standardization, and demonstration of an added value over the common clinical practice are issues needed to be addressed in the transfer of this knowledge from "bench to bedside".

Do Protocadherins Show Prognostic Value in the Carcinogenesis of Human Malignant Neoplasms? Systematic Review and Meta-Analysis

Background:

Protocadherins (PCDHs) have been reported as tumor suppressor genes, implying that these genes may be involved in tumor suppression in a variety of cancers. However, a thorough understanding of the functions and mechanisms of PCDHs remains limited. Our aim was to investigate the methylation profile of PCDHs in human malignant neoplasms.

Methods:

This systematic review has been recorded in PROSPERO (#42019117844) and conducted according to PRISMA’s checklist; search was conducted in LILACS, PubMed, Science Direct, Scopus, and Web of Science databases, manually, with search queries and without date or language restrictions.

Results:

We found 91 articles, of which 26 were used for this meta-analysis and categorized according to the origin of the neoplasia. In total, 3,377 cases were compiled, with PCDH10, PCDH17, and PCDH8 being the most studied; males were 2.22 times more affected than females. Studies have shown significant heterogeneity (p <0.001), with the odds ratio varying between cases and controls [2.20 (95% CI = 1.11– 4.35) to 209.05 (95% CI = 12.64– 2,457.18)], and the value of association between methylation and cancers studied was 26.08 (95% CI = 15.42–44.13).

Conclusion:

In this systematic review, we have demonstrated using meta-analysis that PCDHs could emerge as potential tumor suppressor genes and that a significant increase in methylation may be useful for early detection of different cancers. This work may help in the identification of new prognostic biomarkers in malignant neoplasms.

Epigenetics of Bladder Cancer: Where Biomarkers and Therapeutic Targets Meet

Bladder cancer (BC) is the most common neoplasia of the urothelial tract. Due to its high incidence, prevalence, recurrence and mortality, it remains an unsolved clinical and social problem. The treatment of BC is challenging and, although immunotherapies have revealed potential benefit in a percentage of patients, it remains mostly an incurable disease at its advanced state. Epigenetic alterations, including aberrant DNA methylation, altered chromatin remodeling and deregulated expression of non-coding RNAs are common events in BC and can be driver events in BC pathogenesis. Accordingly, these epigenetic alterations are now being used as potential biomarkers for these disorders and are being envisioned as potential therapeutic targets for the future management of BC. In this review, we summarize the recent findings in these emerging and exciting new aspects paving the way for future clinical treatment of this disease.

The current role of circulating biomarkers in non-muscle invasive bladder cancer

Non-muscle invasive bladder cancer (NMIBC) is characterized by its high rate of disease recurrence and relevant disease progression rates. Up to today clinical models are insufficiently predicting outcomes for reliable patient counseling and treatment decision-making. This particularly is a serious problem in patients with high-risk NMIBC who are at high risk for failure of local treatment and thus candidates for early radical cystectomy or even systemic (neoadjuvant) chemotherapy. Next to its clinical variability, bladder cancer is genetically a highly heterogeneous disease. There is an essential need of biomarkers for improving clinical staging, real-time monitoring of disease with or without active treatment, as well as improved outcome prognostication. Liquid biopsies of circulating biomarkers in the blood and urine are promising non-invasive diagnostics that hold the potential facilitating these needs. In this review we report the latest data and evidence on cell-free circulating tumor desoxyribonucleic acid (ctDNA) and circulating tumor cells (CTC) in NMIBC. We summarize their current status in clinical diagnostics, discuss limitations and address future needs.

Prognostic DNA Methylation Biomarkers in High-risk Non-muscle-invasive Bladder Cancer: A Systematic Review to Identify Loci for Prospective Validation

CONTEXT

High-risk non-muscle-invasive bladder cancer (HR-NMIBC) represents over 30% of all incident urothelial bladder cancers (BCs); patients are at risk of progression, and 20-30% will die from BC within 5 yr. Current guidelines recommend induction and maintenance of intravesical bacillus Calmette-Guérin (BCG) or upfront radical cystectomy for highest-risk disease, treatments with markedly different morbidity, mortality, and patient burden. There are no validated biomarkers to facilitate such treatment decisions. Alterations in DNA methylation are commonplace in BC; hence, measurable changes in DNA methylation represent an opportunity for the discovery of such biomarkers.

OBJECTIVE

To systematically assess the evidence regarding DNA methylation markers as prognosticators for HR-NMIBC.

EVIDENCE ACQUISITION

Standard systematic review methods were employed with searches undertaken in MEDLINE, EMBASE, and PubMed up to January 2019. Studies that included patients with HR-NMIBC and investigated the utility of DNA methylation biomarkers as prognostic tools were included.

EVIDENCE SYNTHESIS

Of 63 prognostic biomarker studies identified, 21 met the protocol-driven inclusion criteria and were directly relevant to HR-NMIBC patient outcomes: tumour recurrence (TR), tumour progression (TP), disease-specific survival (DSS), and overall survival (OS). These studies described 140 methylation markers; of these, the most promising were cadherin-13 (CDH13; hazard ratios [HRs]: 5.1 for TR, 6.6 for TP, 3.8-8.0 for OS), protocadherins (PCDHs; HRs: 4.7 for TR, 2.5 for TP, 3.0-4.8 for OS), Runt domain transcription factor 3 (RUNX3; HR: 5.1 for TP), Homeobox 9 (HOXA9; HR: 1.9 for TR), Islet-1 (ISL1; HRs: 1.7 for TR, 3.3 for TP), and PAX6 (HR: 2.2 for TR).

CONCLUSIONS

This systematic review identifies a number of potentially useful prognostic methylation markers for HR-NMIBC. These loci (CDH13, PCDHs, RUNX3, HOXA9, ISL1, and PAX6) should be validated in prospective studies in order to translate benefit to patients.

PATIENT SUMMARY

Early bladder cancer represents a more complex spectrum of disease than can be assessed by conventional methods Emerging studies on molecular markers will improve our understanding of this disease, and may enable more precise and personalised treatment.

MiR-196b affects the progression and prognosis of human LSCC through targeting PCDH-17

OBJECTIVE

To explore the effect of miR-196bon the biological features of human laryngeal squamous cell carcinoma (LSCC) through targeting PCDH-17.

METHODS

miR-196b and PCDH-17 expressions were determined in tissues, and the targeting relation of miR-196b and PCDH-17 was verified through dual-luciferase reporter system. In vitro, Hep-2 cells were divided into the Control, miR-196b inhibitors, miR-NC, PCDH-17, and miR-196b mimics+PCDH-17 groups. The miR-196b and PCDH-17 expressions were determined by qRT-PCR or/and Western blot, and the biological features by MTT, Annexin V-FITC/PI, wound-healing and Transwell assays.

RESULTS

MiR-196b was found to be up-regulated, while PCDH-17 was down-regulated in a negative correlation in LSCC patients, which was related to histological grade and TNM stage. And low expression of miR-196b and high expression of PCDH-17 contributed to an increase in the 5-year-survival rate of LSCC patients. Besides, miR-196b directly targeted PCDH-17, while miR-196b inhibitors could up-regulate the PCDH-17 in Hep-2 cells. Moreover, miR-196b inhibitors and PCDH-17 curbed Hep-2 cell proliferation but facilitated the apoptosis, with decreases in cell invasion and migration. In addition, no statistical significance was found in cell proliferation, apoptosis, invasion and migration between Control group and miR-196b mimics+PCDH-17 group.

CONCLUSION

LSCC patients exhibited the up-regulated miR-196b and down-regulated PCDH-17, which are correlated with the major clinical features and prognosis. Inhibiting miR-196b may suppress proliferation, migration and invasion abilities, and promote apoptosis of Hep-2 cells via targeting PCDH-17.

Aberrant methylation of PCDH17 gene in high-grade serous ovarian carcinoma

BACKGROUND

Aberrant DNA methylation of protocadherins (PCDHs) has been associated with development and progression of various types of cancer. It could represent possible direction in the search for critically needed tumor biomarkers for ovarian cancer.

OBJECTIVE

To investigate methylation of δ2 group of non-clustered PCDHs in high-grade serous ovarian carcinoma (HGSOC) tissue in comparison with control tissue.

METHODS

We used next-generation sequencing for detecting regions with the most altered methylation. For further confirmation of discovered alterations we used methylation-sensitive high-resolution melting analysis.

RESULTS

PCDH17 methylation was detected in almost 70% of HGSOC patients without any methylation in the group of control samples and was found both in the late stage tumors as well as in the early stage ones. Other selected PCDHs did not show any relevant changes in methylation. Subsequent gene expression analysis of PCDH17 revealed decreased expression in all of the tumor samples in comparison to the control ones. Statistically significant negative correlation was found between methylation and levels of expression suggesting potentially methylation-based silencing.

CONCLUSIONS

Methylation of PCDH17 could play an important role in development and progression of HGSOC and has potential to become a target in the search for new clinical biomarkers.

Aberrant promoter methylation reduced the expression of protocadherin 17 in nasopharyngeal cancer

This study aimed to explore the underlying mechanism of protocadherin 17 (PCDH17) downregulated in nasopharyngeal cancer (NPC). NPC tumor and adjacent tissue samples were collected from NPC patients who received therapy in the Chinese PLA General Hospital. Meanwhile, a normal epithelial cell lines NP96 and 6 NPC and cell lines C666-1, CEN1, CEN2, HNE1, HEN2, and HONE1 were prepared. Then, the expression level of PCDH17 and the methylation level of PCDH17 promoter in both tissues samples and cell lines were determined using the PCR method. Moreover, PCDH17 was overexpressed in CNE2 and HONE1 using Lipo2000. Following this, the proliferation and apoptosis of CNE2 and HONE1 were assessed using MTT and flow cytometry. The expression of PCDH17 was significantly downregulated in NPC tissues compared with the adjacent tissues as well as in the NPC cell lines compared with the normal NP96 cells. Overexpressed PCDH17 could significantly inhibit the proliferation of CNE2 and HONE1 cells but obviously promote the apoptosis of these two cell lines. Aberrant hypermethylation in the promoter might be the explanation of PCDH17 downregulated in PCDH17 and promoted the development of NPC.

Methylation and expression of PTPN22 in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is a fatal disease contributed by both genetic and epigenetic factors. The epigenetic alteration of protein tyrosine phosphatase non-receptor type 22 (PTPN22) and its clinical significance in ESCC were still not yet clarified. A quantitative methylation study of PTPN22 and its expression were conducted in 121 and 31 paired tumor and adjacent normal tissue (ANT), respectively. Moreover, the association between PTPN22 methylation and clinicopathological parameters was evaluated. We found that the methylation level of PTPN22 was significantly elevated in tumor tissues (66.3%) relative to ANT (62.1%) (p=0.005). The methylation level of non-smoking ANT (59.1%) was significant lower than smoking ESCC tissue (65.8%) (p=0.03); similarly, the methylation levels in ANT with no lymph node invasion (57.6%) were significant lower than tumor tissues with lymph node invasion (67.5%) (p=0.001). PTPN22 expression in ESCC was lower than normal tissues, however the difference was not statistically significant (p=0.55). Lower expression was more frequently occurred in N_1-3 and III stage patients, while higher expression was more likely to occur in N₀ and I-II stage patients. Lower expression of PTPN22 was associated with poor overall survival (p=0.04). Taken together, PTPN22 was hypermethylationed in ESCC. Hypermethylation was associated with lymph node invasion. The PTPN22 expression may act as a prognostic biomarker to identify patients at risk of high grade.

The current status and clinical value of circulating tumor cells and circulating cell-free tumor DNA in bladder cancer

Urothelial carcinoma of the bladder (UCB) is a complex disease, which is associated with highly aggressive tumor biologic behavior, especially in patients with muscle-invasive and advanced tumors. Despite multimodal therapy options including surgery, radiotherapy and chemotherapy, UCB patients frequently suffer from poor clinical outcome. Indeed, the potential of diverse opportunities for modern targeted therapies is not sufficiently elucidated in UCB yet. To improve the suboptimal treatment situation in UCB, biomarkers are urgently needed that help detecting minimal residual disease (MRD), predicting therapy response and subsequently prognosis as well as enabling patient stratification for further therapies and therapy monitoring, respectively. To date, decision making regarding treatment planning is mainly based on histopathologic evaluation of biopsies predominantly derived from the primary tumors and on clinical staging. However, both methods are imperfect for sufficient outcome prediction. During disease progression, individual disseminated tumor cells and consecutively metastases can acquire characteristics that do not match those of the corresponding primary tumors, and often are only hardly assessable for further evaluation. Therefore, during recent years, strong efforts were directed to establish non-invasive biomarkers from liquid biopsies. Urine cytology and serum tumor markers have been established for diagnostic purposes, but are still insufficient as universal biomarkers for decision-making and treatment of UCB patients. To date, the clinical relevance of various newly established blood-based biomarkers comprising circulating tumor cells (CTCs), circulating cell-free nucleic acids or tumor-educated platelets is being tested in cancer patients. In this review we summarize the current state and clinical application of CTCs and circulating cell-free tumor DNA originating from blood as biomarkers in patients with different UCB stages.

Epigenetic dysregulation of protocadherins in human disease

Protocadherins (Pcdhs) are a group of cell-cell adhesion molecules that are highly expressed in the nervous system and have a major function in dendrite development and neural circuit formation. However, the role protocadherins play in human health and disease remains unclear. Several recent studies have associated epigenetic dysregulation of protocadherins with possible implications for disease pathogenesis. In this review, we briefly recap the various epigenetic mechanisms regulating protocadherin genes, particularly the clustered Pcdhs. We further outline research describing altered epigenetic regulation of protocadherins in neurological and psychiatric disorders, as well as in cancer and during aging. We additionally present preliminary data on DNA methylation dynamics of clustered protocadherins during fetal brain development, as well as the epigenetic differences distinguishing adult neuronal and glial cells. A deeper understanding of the role of protocadherins in disease is crucial for designing novel diagnostic tools and therapies targeting brain disorders.

Aberrant Promoter Methylation of PCDH17 (Protocadherin 17) in Serum and its Clinical Significance in Renal Cell Carcinoma

Background

Current studies indicated that PCDH17 functions as a tumor suppressor, which is frequently inactivated by aberrant promoter methylation in urologic tumors. The main purpose of this study was to investigate the methylation status of PCDH17 in serum and its clinical significance in renal cell carcinoma (RCC).

Material/Methods

The methylation status of PCDH17 in serum samples of 142 RCC patients and 34 controls was evaluated by methylation-specific PCR (MSP). Then we correlated PCDH17 methylation status with the clinicopathologic features of RCC patients and patient outcomes.

Results

We found that PCDH17 was more frequently methylated in RCC patients than in controls. Moreover, PCDH17 methylation in serum was significantly correlated with advanced stage (p=0.044), higher grade (p=0.019), lymph node metastasis (p=0.008) and tumor progression (p<0.001). In addition, patients with methylated PCDH17 had shorter progression-free survival (p<0.001) and overall survival (p=0.017) than patients without, and PCDH17 methylation in serum was an independent prognostic factor for worse progression-free survival (HR: 4.215, 95% CI: 1.376–9.032, p<0.001) and overall survival (HR: 5.092, 95% CI: 1.149–12.357, p=0.046) of patients with RCC.

Conclusions

The present study indicates that PCDH17 methylation in serum is a frequent event in RCC and associated with risk factors of poor outcomes. Moreover, PCDH17 methylation in serum is a potential prognostic biomarker for patients with RCC after surgery.

Circulating Biomarkers in Bladder Cancer

Bladder cancer is a molecularly heterogeneous disease characterized by multiple unmet needs in the realm of diagnosis, clinical staging, monitoring and therapy. There is an urgent need to develop precision medicine for advanced urothelial carcinoma. Given the difficulty of serial analyses of metastatic tumor tissue to identify resistance and new therapeutic targets, development of non-invasive monitoring using circulating molecular biomarkers is critically important. Although the development of circulating biomarkers for the management of bladder cancer is in its infancy and may currently suffer from lower sensitivity of detection, they have inherent advantages owing to non-invasiveness. Additionally, circulating molecular alterations may capture tumor heterogeneity without the sampling bias of tissue biopsy. This review describes the accumulating data to support further development of circulating biomarkers including circulating tumor cells, cell-free circulating tumor (ct)-DNA, RNA, micro-RNA and proteomics to improve the management of bladder cancer.

New Progress of Epigenetic Biomarkers in Urological Cancer

Urological cancers consist of bladder, kidney, prostate, and testis cancers and they are generally silenced at their early stage, which leads to the loss of the best opportunity for early diagnosis and treatment. Desired biomarkers are scarce for urological cancers and current biomarkers are lack of specificity and sensitivity. Epigenetic alterations are characteristic of nearly all kinds of human malignances including DNA methylation, histone modification, and miRNA regulation. Besides, the detection of these epigenetic conditions is easily accessible especially for urine, best target for monitoring the diseases of urinary system. Here, we summarize some new progress about epigenetic biomarkers in urological cancers, hoping to provide new thoughts for the diagnosis, treatment, and prognosis of urological cancers.

Can we use methylation markers as diagnostic and prognostic indicators for bladder cancer?

Urothelial carcinomas of the urinary bladder have diverse biological and functional characteristics, and numerous factors are likely to be involved in recurrence, progression, and patient survival. While several molecular markers used to evaluate the development and prognosis of bladder cancer have been studied, they are of limited value; therefore, new molecular parameters useful for predicting the prognosis of bladder cancer patients (particularly patients at high risk of progression and recurrence) are required. Recent progress in the understanding of epigenetic modification and gene silencing has provided new opportunities for the detection, treatment, and prevention of cancer. Methylation is an important molecular mechanism in bladder cancer and may have utility as a prognostic and/or diagnostic marker. This review discusses the epigenetic issues involved in the detection and prediction of bladder cancer.

Aberrant Protocadherin17 (PCDH17) Methylation in Serum is a Potential Predictor for Recurrence of Early-Stage Prostate Cancer Patients After Radical Prostatectomy

Background

Prostate cancer is a one of the most common malignant diseases in men worldwide. Now it is a challenge to identify patients at higher risk for relapse and progression after surgery, and more novel prognostic biomarkers are needed. The aim of this study was to investigate the clinical significance of protocadherin17 (PCDH17) methylation in serum and its predictive value for biochemical recurrence (BCR) after radical prostatectomy.

Material/Methods

We evaluated the methylation status of PCDH17 in serum samples of 167 early-stage prostate cancer patients and 44 patients with benign prostatic hyperplasia (BPH) using methylation-specific PCR (MSP), and then evaluated the relationship between PCDH17 methylation and clinicopathologic features. Kaplan-Meier survival analysis and Cox analysis were used to evaluate its predictive value for BCR.

Results

The ratio of PCDH17 methylation in prostate cancer patients was higher than in patients with BPH. Moreover, PCDH17 methylation was significantly associated with advanced pathological stage, higher Gleason score, higher preoperative PSA levels, and BCR. Kaplan-Meier survival analysis indicated that patients with methylated PCDH17 had shorter BCR-free survival time compared to patients with unmethylated PCDH17. Cox regression analysis indicated that PCDH17 methylation was an independent predictive factor for the BCR of patients after radical prostatectomy.

Conclusions

PCDH17 methylation in serum is a frequent event in early-stage prostate cancer, and it is an independent predictor of BCR after radical prostatectomy.

Aberrant methylation of protocadherin 17 and its clinical significance in patients with prostate cancer after radical prostatectomy

Background

Aberrant methylation of protocadherin 17 (PCDH17) has been reported in several human cancers. However, the methylation status of PCDH17 in prostate cancer and its clinical significance remains unclear. The aim of this study was to investigate the methylation status of PCDH17 and its clinical significance in patients with prostate cancer after radical prostatectomy.

Material/Methods

The methylation status of PCDH17 in 152 prostate cancer tissues and 51 non-tumoral prostate tissues was examined by methylation-specific PCR (MSP). Then the association between PCDH17 methylation and clinicopathologic parameters was analyzed. Kaplan-Meier survival analysis, log-rank test and multivariate Cox proportional hazard model analysis were used to analyze the correlation between PCDH17 methylation and prognosis of patients with prostate cancer.

Results

Our data demonstrated that PCDH17 methylation occurred frequently in prostate cancer. PCDH17 methylation was significantly associated with higher pathological Gleason score (P=0.0315), advanced pathological stage (P=0.0260), higher level of preoperative PSA (P=0.0354), positive angiolymphatic invasion (P=0.0461), positive lymph node metastasis (P=0.0362), and biochemical recurrence (BCR) (P=0.0018). In addition, PCDH17 methylation was an independent predictor of poor biochemical recurrence-free (BCR-free) survival and overall survival for patients with prostate cancer.

Conclusions

PCDH17 methylation is a frequent tumor-specific event in prostate cancer, and is significantly correlated with shorter BCR-free survival and overall survival of patients with prostate cancer after radical prostatectomy. PCDH17 methylation in tumor samples after radical prostatectomy may be used as an independent prognostic biomarker.