Association of DSC3 mRNA down-regulation in prostate cancer with promoter hypermethylation and poor prognosis

Bioinformatic miRNA-mRNAs Analysis Revels to miR-934 as a Potential Regulator of the Epithelial-Mesenchymal Transition in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is one of the most aggressive subtypes of breast cancer and has the worst prognosis. In patients with TNBC tumors, the tumor cells have been reported to have mesenchymal features, which help them migrate and invade. Various studies on cancer have revealed the importance of microRNAs (miRNAs) in different biological processes of the cell in that aberrations, in their expression, lead to alterations and deregulations in said processes, giving rise to tumor progression and aggression. In the present work, we determined the miRNAs that are deregulated in the epithelial-mesenchymal transition process in breast cancer. We discovered that 25 miRNAs that regulate mesenchymal genes are overexpressed in patients with TNBC. We found that miRNA targets modulate different processes and pathways, such as apoptosis, FoxO signaling pathways, and Hippo. We also found that the expression level of miR-934 is specific to the molecular subtype of the triple-negative breast cancer and modulates a set of related epithelial-mesenchymal genes. We determined that miR-934 inhibition in TNBC cell lines inhibits the migratory abilities of tumor cells.

ITGA9: Potential Biomarkers and Therapeutic Targets in Different Tumors

Abstract:

Integrins are a class of a cell surface adhesion molecule which composed of α subunit (ITGA) and β subunit (ITGB). They belong to heterodimer transmembrane glycoproteins. Its main function in organisms is as the receptor of cell adhesion molecules (CAMs) and extracellular matrix (ECM). According to the current research integration analysis, integrin α9 (ITGA9) is one of the integrin subunits, and there are few studies on ITGA9 among integrins. ITGA9 can improve cell migration and regulate various cellular biological functions, such as tumor cell proliferation, adhesion, invasion, and angiogenesis. But its abnormal expression mechanism in cancer and its specific role in tumor growth and metastasis are still unknown to a great extent. This review reveals the role of ITGA9 in the complex pathogenesis of many tumors and cancers, providing a new direction for the treatment of tumors and cancers. Relevant studies were retrieved and collected through the PubMed system. After determining ITGA9 as the research object, we found the close relationship between ITGA9 and tumorigenesis through the analysis of the research articles on ITGA9 in the PubMed system in the last 15 years, and further determined the references mainly based on the influencing factors of the articles. Thus, the role of ITGA9 in tumor and cancer genesis, proliferation, and metastasis was reviewed and analyzed. ITGA9 is an integrin subunit, which has been proved to be abnormally expressed in many tumors. After sorting and analyzing the research data, it was found that the abnormal expression of ITGA9 in a variety of tumors, including glioblastoma, rhabdomyosarcoma, melanoma, hepatocellular carcinoma, nasopharyngeal carcinoma, multiple myeloma, non-small cell lung cancer, and prostate cancer, was closely related to the proliferation, metastasis, adhesion, and angiogenesis of tumor cells. These results suggest that ITGA9 plays an important role in the occurrence and development of tumors. The integrin subunit ITGA9 may serve as a biomarker for the diagnosis of tumors and a potential therapeutic target for anti-tumor therapies.

Desmosomes as Signaling Hubs in the Regulation of Cell Behavior

Desmosomes are intercellular junctions, which preserve tissue integrity during homeostatic and stress conditions. These functions rely on their unique structural properties, which enable them to respond to context-dependent signals and transmit them to change cell behavior. Desmosome composition and size vary depending on tissue specific expression and differentiation state. Their constituent proteins are highly regulated by posttranslational modifications that control their function in the desmosome itself and in addition regulate a multitude of desmosome-independent functions. This review will summarize our current knowledge how signaling pathways that control epithelial shape, polarity and function regulate desmosomes and how desmosomal proteins transduce these signals to modulate cell behavior.

DNA methylation signatures associated with prognosis of gastric cancer

Background

Few studies have examined prognostic outcomes-associated molecular signatures other than overall survival (OS) for gastric cancer (GC). We aimed to identify DNA methylation biomarkers associated with multiple prognostic outcomes of GC in an epigenome-wide association study.

Methods

Based on the Cancer Genome Atlas (TCGA), DNA methylation loci associated with OS (n = 381), disease-specific survival (DSS, n = 372), and progression-free interval (PFI, n = 383) were discovered in training set subjects (false discovery rates < 0.05) randomly selected for each prognostic outcome and were then validated in remaining subjects (P-values < 0.05). Key CpGs simultaneously validated for OS, DSS, and PFI were further assessed for disease-free interval (DFI, n = 247). Gene set enrichment analyses were conducted to explore the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathways simultaneously enriched for multiple GC prognostic outcomes. Methylation correlated blocks (MCBs) were identified for co-methylation patterns associated with GC prognosis. Based on key CpGs, risk score models were established to predict four prognostic outcomes. Spearman correlation analyses were performed between key CpG sites and their host gene mRNA expression.

Results

We newly identified DNA methylation of seven CpGs significantly associated with OS, DSS, and PFI of GC, including cg10399824 (GRK5), cg05275153 (RGS12), cg24406668 (MMP9), cg14719951(DSC3), and cg25117092 (MED12L), and two in intergenic regions (cg11348188 and cg11671115). Except cg10399824 and cg24406668, five of them were also significantly associated with DFI of GC. Neuroactive ligand-receptor interaction pathway was suggested to play a key role in the effect of DNA methylation on GC prognosis. Consistent with individual CpG-level association, three MCBs involving cg11671115, cg14719951, and cg24406668 were significantly associated with multiple prognostic outcomes of GC. Integrating key CpG loci, two risk score models performed well in predicting GC prognosis. Gene body DNA methylation of cg14719951, cg10399824, and cg25117092 was associated with their host gene expression, whereas no significant associations between their host gene expression and four clinical prognostic outcomes of GC were observed.

Conclusions

We newly identified seven CpGs associated with OS, DSS, and PFI of GC, with five of them also associated with DFI, which might inform patient stratification in clinical practices.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08389-0.

Differential gene expression profile between progressive and de novo muscle invasive bladder cancer and its prognostic implication

This study aimed to ascertain gene expression profile differences between progressive muscle-invasive bladder cancer (MIBC) and de novo MIBC, and to identify prognostic biomarkers to improve patients’ treatment. Retrospective multicenter study in which 212 MIBC patients who underwent radical cystectomy between 2000 and 2019 were included. Gene expression profiles were determined in 26 samples using Illumina microarrays. The expression levels of 94 genes were studied by quantitative PCR in an independent set of 186 MIBC patients. In a median follow-up of 16 months, 46.7% patients developed tumor progression after cystectomy. In our series, progressive MIBC patients show a worse tumor progression (p = 0.024) and cancer-specific survival (CSS) (p = 0.049) than the de novo group. A total of 480 genes were found to be differently expressed between both groups. Differential expression of 24 out of the 94 selected genes was found in an independent cohort. RBPMC2 and DSC3 were found as independent prognostic biomarkers of tumor progression and CALD1 and LCOR were identified as prognostic biomarkers of CSS between both groups. In conclusion, progressive and de novo MIBC patients show different clinical outcome and gene expression profiles. Gene expression patterns may contribute to predict high-risk of progression to distant metastasis or CSS.

Label-Free Mass Spectrometry-Based Plasma Proteomics Identified LY6D, DSC3, CDSN, SERPINB12, and SLURP1 as Novel Protein Biomarkers For Pulmonary Tuberculosis

Aim:

We aimed to identify new plasma biomarkers for the diagnosis of Pulmonary Tuberculosis (PTB).

Background:

Tuberculosis is an ancient infectious disease that remains one of the major global health problems. Until now, effective, convenient, and affordable methods for diagnosis of PTB were still lacking.

Objective:

This study focused on constructing a label-free LC-MS/MS-based comparative proteomics between six tuberculosis patients and six healthy controls to identify Differentially Expressed Proteins (DEPs) in plasma.

Methods:

To reduce the influences of high-abundant proteins, albumin and globulin were removed from plasma samples using affinity gels. Then DEPs from the plasma samples were identified using a label-free Quadrupole-Orbitrap LC-MS/MS system. The results were analyzed by the protein database search algorithm SEQUEST-HT to identify mass spectra to peptides. The predictive abilities of combinations of host markers were investigated by General Discriminant Analysis (GDA), with Leave-One-Out Cross- Validation (LOOCV).

Results:

A total of 572 proteins were identified and 549 proteins were quantified. The threshold for DEPs was set as adjusted p-value < 0.05 and fold change ≥1.5 or ≤0.6667, 32 DEPs were found. ClusterVis, TBtools, and STRING were used to find new potential biomarkers of PTB. Six proteins, LY6D, DSC3, CDSN, FABP5, SERPINB12, and SLURP1, which performed well in the LOOCV method validation, were termed as potential biomarkers. The percentage of cross-validated grouped cases correctly classified and original grouped cases correctly classified is greater than or equal to 91.7%.

Conclusion:

We successfully identified five candidate biomarkers for immunodiagnosis of PTB in plasma, LY6D, DSC3, CDSN, SERPINB12, and SLURP1. Our work supported this group of proteins as potential biomarkers for PTB, and be worthy of further validation.

Desmocollin 3 has a tumor suppressive activity through inhibition of AKT pathway in colorectal cancer

Desmocollin 3 (DSC3) is a transmembrane adhesion protein of desmosomes and involved in carcinogenesis in various cancer types. Downregulation of DSC3 has been reported in colorectal cancer (CRC). However, the function of DSC3 in CRC has not yet been elucidated. In this study, we performed cell-based functional analysis after DSC3 overexpression by stable transfection and knockdown by siRNA in CRC cells. It turned out that overexpression of DSC3 reduced cell proliferation, colony forming ability, induced G0/G1 cell cycle arrest and promoted apoptosis. Further pathway analysis showed that overexpression of DSC3 significantly inhibited the activity of AKT pathway and increased the expression of E-cadherin as well as p53 and p21. In contrast, siRNA-mediated knockdown of DSC3 increased cell proliferation and colony formation, activated the AKT pathway and decreased the expression of E-cadherin as well as p53 and p21. Additionally, in primary CRC patient samples, the expression of DSC3 protein was significantly related to the expression of desmocollin 1 (DSC1) and desmocollin 2 (DSC2) as well as E-cadherin (p < 0.001 respectively). Taken together, our data reveal that DSC3 suppresses CRC cell growth through inhibition of AKT pathway and regulation of E-cadherin. DSC3 may serve as a novel therapeutic target for CRC.

Integrated analysis of genome-wide DNA methylation and gene expression profiles identifies potential novel biomarkers of rectal cancer

DNA methylation was regarded as the promising biomarker for rectal cancer diagnosis. However, the optimal methylation biomarkers with ideal diagnostic performance for rectal cancer are still limited. To identify new molecular markers for rectal cancer, we mapped DNA methylation and transcriptomic profiles in the six rectal cancer and paired normal samples. Further analysis revealed the hypermethylated probes in cancer prone to be located in gene promoter. Meanwhile, transcriptome analysis presented 773 low-expressed and 1,161 over-expressed genes in rectal cancer. Correction analysis identified a panel of 36 genes with an inverse correlation between methylation and gene expression levels, including 10 known colorectal cancer related genes. From the other 26 novel marker genes, GFRA1 and GSTM2 were selected for further analysis on the basis of their biological functions. Further experiment analysis confirmed their methylation and expression status in a larger number (44) of rectal cancer samples, and ROC curves showed higher AUC than SEPT9, which has been used as a biomarker in rectal cancer. Our data suggests that aberrant DNA methylation of contiguous CpG sites in methylation array may be potential diagnostic markers of rectal cancer.

Aggressive rat prostate tumors reprogram the benign parts of the prostate and regional lymph nodes prior to metastasis

In order to grow and spread tumors need to interact with adjacent tissues. We therefore hypothesized that small but aggressive prostate cancers influence the rest of the prostate and regional lymph nodes differently than tumors that are more indolent. Poorly metastatic (Dunning AT1) or highly metastatic (Dunning MLL) rat prostate tumor cells were injected into the ventral prostate lobe of immunocompetent rats. After 10 days—when the tumors occupied about 30% of the prostate lobe and lymph node metastases were undetectable—the global gene expression in tumors, benign parts of the prostate, and regional iliac lymph nodes were examined to define tumor-induced changes related to preparation for future metastasis. The tumors induced profound effects on the gene expression profiles in the benign parts of the prostate and these were strikingly different in the two tumor models. Gene ontology enrichment analysis suggested that tumors with high metastatic capacity were more successful than less metastatic tumors in inducing tumor-promoting changes and suppressing anti-tumor immune responses in the entire prostate. Some of these differences such as altered angiogenesis, nerve density, accumulation of T-cells and macrophages were verified by immunohistochemistry. Gene expression alterations in the regional lymph nodes suggested decreased quantity and activation of immune cells in MLL-lymph nodes that were also verified by immunostaining. In summary, even when small highly metastatic prostate tumors can affect the entire tumor-bearing organ and pre-metastatic lymph nodes differently than less metastatic tumors. When the kinetics of these extratumoral influences (by us named TINT = tumor instructed normal tissue) are more precisely defined they could potentially be used as markers of disease aggressiveness and become therapeutic targets.

Characterization of long noncoding RNA and messenger RNA signatures in melanoma tumorigenesis and metastasis

The incidence of melanoma, the most aggressive and life-threatening form of skin cancer, has significantly risen over recent decades. Therefore, it is essential to identify the mechanisms that underlie melanoma tumorigenesis and metastasis and to explore novel and effective melanoma treatment strategies. Accumulating evidence s uggests that aberrantly expressed long noncoding RNAs (lncRNAs) have vital functions in multiple cancers. However, lncRNA functions in melanoma tumorigenesis and metastasis remain unclear. In this study, we investigated lncRNA and messenger RNA (mRNA) expression profiles in primary melanomas, metastatic melanomas and normal skin samples from the Gene Expression Omnibus database. We used GSE15605 as the training set (n = 74) and GSE7553 as the validation set (n = 58). In three comparisons (primary melanoma versus normal skin, metastatic melanoma versus normal skin, and metastatic melanoma versus primary melanoma), 178, 295 and 48 lncRNAs and 847, 1758, and 295 mRNAs were aberrantly expressed, respectively. We performed Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses to examine the differentially expressed mRNAs, and potential core lncRNAs were predicted by lncRNA-mRNA co-expression networks. Based on our results, 15 lncRNAs and 144 mRNAs were significantly associated with melanoma tumorigenesis and metastasis. A subsequent analysis suggested a critical role for a five-lncRNA signature during melanoma tumorigenesis and metastasis. Low expression of U47924.27 was significantly associated with decreased survival of patients with melanoma. To the best of our knowledge, this study is the first to explore the expression patterns of lncRNAs and mRNAs during melanoma tumorigenesis and metastasis by re-annotating microarray data from the Gene Expression Omnibus (GEO) microarray dataset. These findings reveal potential roles for lncRNAs during melanoma tumorigenesis and metastasis and provide a rich candidate reservoir for future studies.

Pathophysiology of the Desmo-Adhesome

Advances in our understanding of desmosomal diseases have provided a clear demonstration of the key role played by desmosomes in tissue and organ physiology, highlighting the importance of their dynamic and finely regulated structure. In this context, non-desmosomal regulatory molecules have acquired increasing relevance in the study of this organelle resulting in extending the desmosomal interactome, named the "desmo-adhesome." Spatiotemporal changes in the expression and regulation of the desmo-adhesome underlie a number of genetic, infectious, autoimmune, and malignant conditions. The aim of the present article was to examine the structural and functional relationship of the desmosome, by providing a comprehensive, yet focused overview of the constituents targeted in human disease. The inclusion of the novel regulatory network in the desmo-adhesome pathophysiology opens new avenues to a deeper understanding of desmosomal diseases, potentially unveiling pathogenic mechanisms waiting to be explored. J. Cell. Physiol. 232: 496-505, 2017. © 2016 Wiley Periodicals, Inc.

Stage at presentation and survival outcomes of patients with Gleason 8-10 prostate cancer and low prostate-specific antigen

OBJECTIVE

To evaluate outcomes for men with high Gleason score and low prostate-specific antigen (PSA) prostate cancer. Low PSA levels among men with Gleason 8-10 prostate cancer may be owing to cellular dedifferentiation rather than low disease burden. We hypothesized that men with Gleason 8-10 prostate cancer and low PSA levels have increased risk for advanced disease and worse survival.

MATERIALS AND METHODS

Men diagnosed from 2004 to 2007 with Gleason 8-10 prostate adenocarcinoma in the National Cancer Data Base were included. Patients were stratified by PSA levels at diagnosis: 0.1 to 3.9, 4.0 to 9.9, 10.0 to 19.9, and≥20.0ng/ml. Outcomes were clinical TNM category, pathologic stage (for prostatectomy patients), and overall survival (OS). Kaplan-Meier analysis and Cox proportional hazards models were used.

RESULTS

A total of 37,283 patients were included. Men with PSA levels of<4.0ng/ml were more likely than those with PSA levels of 4 to 9.9ng/ml to present with clinical T3-4 disease (15% vs. 10%, P<0.001), nodal (4% vs. 2%, P<0.001) and distant (5% vs. 3%, P<0.001) metastasis. However, among patients treated with prostatectomy, lower PSA levels were not associated with increased likelihood of pathologic T3-4 disease or nodal metastasis. Six-year OS was 89.1% (PSA: 0.1-3.9ng/ml) vs. 91.0% (PSA: 4.0-9.9ng/ml) for prostatectomy (log-rank P<0.001), and 75.8% vs. 81.0% for radiotherapy (P<0.001). Multivariable analyses showed OS of patients with PSA levels of 0.1 to 3.9ng/ml to be similar to those with PSA levels of 10 to 19.9ng/ml.

CONCLUSIONS

Patients with Gleason 8-10 cancer and PSA levels of<4.0ng/ml have more aggressive disease than those with PSA levels of 4 to 9.9ng/ml; these low PSA cancers behave more like those with PSA levels of 10 to 19.9ng/ml. Further study is needed to evaluate potential biological differences in these patients with low PSA-producing cancers.

Identification of Novel Epigenetic Markers of Prostate Cancer by NotI-Microarray Analysis

A significant need for reliable and accurate cancer diagnostics and prognosis compels the search for novel biomarkers that would be able to discriminate between indolent and aggressive tumors at the early stages of disease. The aim of this work was identification of potential diagnostic biomarkers for characterization of different types of prostate tumors. NotI-microarrays with 180 clones associated with chromosome 3 genes/loci were applied to determine genetic and epigenetic alterations in 33 prostate tumors. For 88 clones, aberrations were detected in more than 10% of tumors. The major types of alterations were DNA methylation and/or deletions. Frequent methylation of the discovered loci was confirmed by bisulfite sequencing on selective sampling of genes: FGF12, GATA2, and LMCD1. Three genes (BHLHE40, BCL6, and ITGA9) were tested for expression level alterations using qPCR, and downregulation associated with hypermethylation was shown in the majority of tumors. Based on these data, we proposed the set of potential biomarkers for detection of prostate cancer and discrimination between prostate tumors with different malignancy and aggressiveness: BHLHE40, FOXP1, LOC285205, ITGA9, CTDSPL, FGF12, LOC440944/SETD5, VHL, CLCN2, OSBPL10/ZNF860, LMCD1, FAM19A4, CAND2, MAP4, KY, and LRRC58. Moreover, we probabilistically estimated putative functional relations between the genes within each set using the network enrichment analysis.

Identification of immunohistochemical markers for distinguishing lung adenocarcinoma from squamous cell carcinoma

BACKGROUND

Immunohistochemical staining has been widely used in distinguishing lung adenocarcinoma (LUAD) from lung squamous cell carcinoma (LUSC), which is of vital importance for the diagnosis and treatment of lung cancer. Due to the lack of a comprehensive analysis of different lung cancer subtypes, there may still be undiscovered markers with higher diagnostic accuracy.

METHODS

Herein first, we systematically analyzed high-throughput data obtained from The Cancer Genome Atlas (TCGA) database. Combining differently expressed gene screening and receiver operating characteristic (ROC) curve analysis, we attempted to identify the genes which might be suitable as immunohistochemical markers in distinguishing LUAD from LUSC. Then we detected the expression of six of these genes (MLPH, TMC5, SFTA3, DSG3, DSC3 and CALML3) in lung cancer sections using immunohistochemical staining.

RESULTS

A number of genes were identified as candidate immunohistochemical markers with high sensitivity and specificity in distinguishing LUAD from LUSC. Then the staining results confirmed the potentials of the six genes (MLPH, TMC5, SFTA3, DSG3, DSC3 and CALML3) in distinguishing LUAD from LUSC, and their sensitivity and specificity were not less than many commonly used markers.

CONCLUSIONS

The results revealed that the six genes (MLPH, TMC5, SFTA3, DSG3, DSC3 and CALML3) might be suitable markers in distinguishing LUAD from LUSC, and also validated the feasibility of our methods for identification of candidate markers from high-throughput data.

Integrated analysis of epigenomic and genomic changes by DNA methylation dependent mechanisms provides potential novel biomarkers for prostate cancer

Epigenetic silencing mediated by CpG methylation is a common feature of many cancers. Characterizing aberrant DNA methylation changes associated with tumor progression may identify potential prognostic markers for prostate cancer (PCa). We treated two PCa cell lines, 22Rv1 and DU-145 with the demethylating agent 5-Aza 2’–deoxycitidine (DAC) and global methylation status was analyzed by performing methylation-sensitive restriction enzyme based differential methylation hybridization strategy followed by genome-wide CpG methylation array profiling. In addition, we examined gene expression changes using a custom microarray. Gene Set Enrichment Analysis (GSEA) identified the most significantly dysregulated pathways. In addition, we assessed methylation status of candidate genes that showed reduced CpG methylation and increased gene expression after DAC treatment, in Gleason score (GS) 8 vs. GS6 patients using three independent cohorts of patients; the publically available The Cancer Genome Atlas (TCGA) dataset, and two separate patient cohorts. Our analysis, by integrating methylation and gene expression in PCa cell lines, combined with patient tumor data, identified novel potential biomarkers for PCa patients. These markers may help elucidate the pathogenesis of PCa and represent potential prognostic markers for PCa patients.

150th Anniversary Series: Desmosomes and the Hallmarks of Cancer

Desmosomes represent adhesive, spot-like intercellular junctions that in association with intermediate filaments mechanically link neighboring cells and stabilize tissue architecture. In addition to this structural function, desmosomes also act as signaling platforms involved in the regulation of cell proliferation, differentiation, migration, morphogenesis, and apoptosis. Thus, deregulation of desmosomal proteins has to be considered to contribute to tumorigenesis. Proteolytic fragmentation and downregulation of desmosomal cadherins and plaque proteins by transcriptional or epigenetic mechanisms were observed in different cancer entities suggesting a tumor-suppressive role. However, discrepant data in the literature indicate that context-dependent differences based on alternative intracellular, signal transduction lead to altered outcome. Here, modulation of Wnt/β-catenin signaling by plakoglobin or desmoplakin and of epidermal growth factor receptor signaling appears to be of special relevance. This review summarizes current evidence on how desmosomal proteins participate in carcinogenesis, and depicts the molecular mechanisms involved.

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.