Clinical significance of protocadherin-8 (PCDH8) promoter methylation in bladder cancer

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.

Protocadherin 8 (PCDH8) Inhibits Proliferation, Migration, Invasion, and Angiogenesis in Esophageal Squamous Cell Carcinoma

BACKGROUND Protocadherin 8 (PCDH8) functions as a tumor-suppressor gene in many types of cancer. This study aimed to investigate the role of PCDH8 in esophageal squamous cell carcinoma (ESCC). MATERIAL AND METHODS Cell proliferation, apoptosis, transwell assay, tube formation assays, and tumor xenograft experiment were performed to explore the role of PCDH8 in the progression of ESCC. RESULTS PCDH8 was found to be downregulated in ESCC cells. Ectopic expression of PCDH8 blocked proliferation, invasion, and migration and induced apoptosis in ESCC cells. Furthermore, vascular endothelial growth factor A (VEGFA) secretion and the AKT signaling pathway were also inhibited when PCDH8 was upregulated. PCDH8 overexpression suppressed epithelial-mesenchymal transition (EMT) and pro-angiogenic activity of ESCC cells. In a mouse model of ESCC xenograft tumors, PCDH8 overexpression remarkably restrained tumor cell growth, with the tumor inhibition rate of 75.2%. PCDH8 was the target of miR-200c and had a negative correlation with miR-200c. CONCLUSIONS PCDH8 exerts a tumor-suppressive effect against ESCC cells. However, further studies are required to elucidate the exact molecular mechanism underlying the antitumor activity of PCDH8 in ESCC.

MiR-200a-3p promoted the malignant behaviors of ovarian cancer cells through regulating PCDH9

BACKGROUND

Increasing evidence has revealed that the aberrant expression of microRNAs (miRNAs) plays vital roles in the development and progression of ovarian cancer. MiR-200a-3p was found to act as an oncogene in a variety of cancers, however, the expression and function of miR-200a-3p in ovarian cancer has not been characterized.

MATERIALS AND METHODS

The expression of miR-200a-3p in ovarian cancer tissues and cell lines was detected by the RT-qPCR. The influence of miR-200a-3p on the growth of ovarian cancer cells was determined with the Cell Counting Kit-8 assay, colony formation and cell invasion assay. The binding of miR-200a-3p with the 3'-untranslated region (UTR) of PDCH9 was detected by luciferase reporter assay. The expression of PCDH9 was investigated by RT-qPCR and Western blot analysis.

RESULTS

miR-200a-3p was up-regulated in ovarian cancer tissues and cell lines. Highly expressed miR-200a-3p was significantly associated with the tumor size, tumor metastasis and TNM stage. Overexpression of miR-200a-3p markedly promoted the proliferation, colony formation and invasion of ovarian cancer cells. Functional study uncovered that miR-200a-3p bound the 3'-untranslated region (UTR) of PCDH9 and decreased the expression of PCDH9 in ovarian cancer cells. The expression of miR-200a-3p in ovarian cancer tissues was significantly negatively correlated with that of PCDH9. Restored PCDH9 inhibited the promoting effect of miR-200a-3p on the proliferation of ovarian cancer cells.

CONCLUSION

Our results suggested the potential oncogenic function of miR-200a-3p via modulating PCDH9 in ovarian cancer.

Retracted Article: Overexpression of PCDH8 inhibits proliferation and invasion, and induces apoptosis in papillary thyroid cancer cells

Protocadherin8 (PCDH8), a member of the protocadherin (PCDH) family, is involved in the progression of several types of cancers. However, the expression and biological roles of PCDH8 in papillary thyroid carcinoma (PTC) remain largely unknown. Therefore, in the present study, we detected the expression of PCDH8 in human PTC tissues and cell lines, and evaluated its role in PTC cells. Our results demonstrated that PCDH8 was lowly expressed in human PTC tissues and cell lines. In addition, ectopic expression of PCDH8 efficiently inhibited the proliferation, migration and invasion of PTC cells, as well as prevented the epithelial-mesenchymal transition (EMT) phenotype in PTC cells. Furthermore, PCDH8 efficiently induced apoptosis and autophagy in PTC cells. Mechanistically, overexpression of PCDH8 significantly prevented the activation of the Wnt/β-catenin pathway in PTC cells. Taken together, these findings showed that overexpression of PCDH8 inhibits proliferation and migration/invasion, and induces apoptosis of PTC cells through the Wnt/β-catenin signaling pathway.

Protocadherin8 (PCDH8), a member of the protocadherin (PCDH) family, is involved in the progression of several types of cancers.

Altered methylation of glucosylceramide synthase promoter regulates its expression and associates with acquired multidrug resistance in invasive ductal breast cancer

Overexpression of glucosylceramide synthase (GCS) increases multidrug resistance (MDR) in many cancer cells. However, its mechanism is unknown. The aim of the present study is to detect the association of methylation at the GCS gene promoter with its expression and MDR in invasive ductal breast cancer. 40 cases GCS-positive and 40 cases GCS-negative primary breast carcinoma samples, three drug-sensitive breast cancer cell lines and one multidrug-resistant breast cancer cell line were used. Immunohistochemistry, methylation-specific PCR (MSP), quantitative real-time (qPCR), westernblot and cytotoxicity assay techniques were employed. Thwe results revealed that there was a statistically negative correlation between GCS CpG islands methylation and GCS phenotype in patients with breast cancer. GCS CpG islands methylation was negatively associated with high ER, meanwhile positively with high HER-2 status. Similar results were obtained from the analysis of breast cancer cell lines. Treatment with the demethylating agent 5-aza-2′-deoxycytidine (5-Aza-dc) changed the GCS promoter methylation pattern in three sensitive cells and also caused increased drug resistance of them. These results suggested that the changes of DNA methylation status of the GCS promoter correlates with multidrug resistance in breast cancer.

The prognostic role of epigenetic dysregulation in bladder cancer: A systematic review

BACKGROUND

Despite adequate treatment and follow-up, around one fifth of patients with localized bladder cancer will present with disease progression. Adequate prognostic biomarkers are lacking to define patients who are at risk. Mutations in chromatin remodeling genes are more frequently found in bladder cancer than in any other solid tumor. However, the prognostic relevance of epigenetic dysregulation has not been established and may offer an opportunity for biomarker discovery.

METHODS

Looking for prognostic epigenetic factors, we performed a comprehensive PubMed search using keywords such as "bladder cancer", "chromatin remodeling", "gene methylation" and "epigenetics". We only included studies reporting on the association of epigenetic markers with prognostic outcomes such as recurrence, progression or survival.

RESULTS

Of 1113 results, 87 studies met the inclusion criteria, which represented a total of 85 epigenetic markers with potential prognostic relevance. No prospective studies were identified. Seventy-three percent (64/87) of the studies involved mixed cohorts of muscle invasive and non-muscle invasive bladder cancer. Promoter methylation of genes with putative prognostic value affected cellular processes such as cell cycle, apoptosis, cell-adhesion or migration, as well as critical pathways such as MAP-kinase or Wnt. Alteration of chromatin regulatory elements suggest a prognostic relevance alterations leading to a predominantly silenced chromatin state.

CONCLUSIONS

The prognostic impact of epigenetic alterations in bladder cancer is still unclear. Prospective evaluation of methylation marks and chromatin remodeling gene alterations using consistent methods and criteria is warranted.

PCDH8 inhibits glioma cell proliferation by negatively regulating the AKT/GSK3β/β-catenin signaling pathway

Protocadherin-8 (PCDH8), a member of the protocadherin superfamily of proteins, is frequently lost in numerous types of cancer. However, the role that PCDH8 serves in human glioma, and the molecular mechanisms underlying this, remain unclear. Data from the present study demonstrated that the expression levels of PCDH8 mRNA and protein were significantly decreased in human glioma tissue compared with normal brain tissue. This suggested that PCDH8 is associated with the development of glioma. Thus, the role of PCDH8 in glioma cell proliferation was investigated by silencing and overexpressing PCDH8 in U251 glioma cells. Overexpression of PCDH8 significantly inhibited glioma cell proliferation, while silencing of PCDH8 using small interfering RNA promoted glioma cell proliferation. Restoration of PCDH8 decreased phosphorylated (p)-Rac-α serine/threonine-protein kinase (AKT) [Threonine (T)308/Serine (S)473] and p-glycogen synthase kinase-3β (p-GSK3β) (S9) protein expression, thereby reducing the level of β-catenin when compared with the control. By contrast, silencing of PCDH8 increased levels of p-AKT (T308/S473) and p-GSK3β (S9), thereby increasing the level of β-catenin. In conclusion, the results of the present study suggested that PCDH8 suppressed glioma cell proliferation, and that the loss of PCDH8 may stimulate the proto-oncogene Wnt/β-catenin signaling pathway and therefore promote glioma cell proliferation.

Association between protocadherin 8 promoter hypermethylation and the pathological status of prostate cancer

Promoter hypermethylation of tumor suppressor genes has been confirmed to serve a pivotal role in tumorigenesis. Protocadherin 8 (PCDH8), a novel tumor suppressor gene, has been reported to be inactivated by promoter hypermethylation a number of cancer types, including bladder cancer and renal cell carcinoma. The aim of the present study was to investigate the occurrence of PCDH8 hypermethylation in prostate cancer and its potential as a novel biomarker of prostate cancer. The transcriptional levels of PCDH8 were examined by quantitative polymerase chain reaction (PCR) in 82 prostate cancer tissues as well as 30 prostate hyperplasia tissues, and verified the protein level by western blot analysis of representative samples. PCDH8 expression levels were found to be reduced to 0.30±0.10 in 70.7% (58/82) of prostate cancer tissues. To identify the possible reason for mRNA downregulation, the methylation status of the PCDH8 promoter was assessed in prostate cancer tissues and prostate hyperplasia tissues by methylation-specific PCR (MSP). A total of 47 prostate cancer patients who exhibited reduced PCDH8 expression (57.3%; 47/82) also showed promoter hypermethylation (47/58). None of the samples (0/30) in the benign prostate hyperplasia group were positive on MSP. Furthermore, the associations between the methylation status of the PCDH8 promoter and various clinicopathological features of prostate cancer were analyzed, revealing that the methylation status of PCDH8 was closely associated with tumor size, tumor shape (papillary/non-papillary), tumor stage and tumor grade (all P<0.05), while there were no correlations with the age of the patients or the number of tumors (P>0.05). Additionally, patients with hypermethylation of the PCDH8 gene promoter had a relapse rate of 36.17% and a mortality rate of 29.79%, which were significantly higher than the hypermethylation-negative patients (P<0.05), indicating a poorer prognosis. Therefore, the methylation status of the PCDH8 gene in prostate cancer may be an important marker for use in the early diagnosis and prediction of prognosis in prostate cancer.

Nemo-like kinase 1 (Nlk1) and paraxial protocadherin (PAPC) cooperatively control Xenopus gastrulation through regulation of Wnt/planar cell polarity (PCP) signaling

The Wnt/planar cell polarity (PCP) pathway directs cell migration during vertebrate gastrulation and is essential for proper embryonic development. Paraxial protocadherin (PAPC, Gene Symbol pcdh8.2) is an important activator of Wnt/PCP signaling during Xenopus gastrulation, but how PAPC activity is controlled is incompletely understood. Here we show that Nemo-like kinase 1 (Nlk1), an atypical mitogen-activated protein (MAP) kinase, physically associates with the C-terminus of PAPC. This interaction mutually stabilizes both proteins by inhibiting polyubiquitination. The Nlk1 mediated stabilization of PAPC is essential for Wnt/PCP signaling, tissue separation and gastrulation movements. We identified two conserved putative phosphorylation sites in the PAPC C-terminus that are critical for Nlk1 mediated PAPC stabilization and Wnt/PCP regulation. Intriguingly, the kinase activity of Nlk1 itself was not essential for its cooperation with PAPC, suggesting an indirect regulation for example by impeding a different kinase that promotes protein degradation. Overall these results outline a novel, kinase independent role of Nlk1, wherein Nlk1 regulates PAPC stabilization and thereby controls gastrulation movements and Wnt/PCP signaling during development.

Epigenome-wide analysis of DNA methylation reveals a rectal cancer-specific epigenomic signature

Aim: The aim of the present study is to address a genome-wide search for novel methylation biomarkers in the rectal cancer (RC), as only scarce information on methylation profile is available. Materials & methods: We analyzed methylation status in 25 pairs of RC and adjacent healthy mucosa using the Illumina Human Methylation 450 BeadChip. Results: We found significantly aberrant methylation in 33 genes. After validation of our results by pyrosequencing, we found a good agreement with our findings. The BPIL3 and HBBP1 genes resulted hypomethylated in RC, whereas TIFPI2, ADHFE1, FLI1 and TLX1 were hypermethylated. An external validation by TCGA datasets confirmed the results. Conclusion: Our study, with external validation, has demonstrated the feasibility of using specific methylated DNA signatures for developing biomarkers in RC.

PCDH8 is Frequently Inactivated by Promoter Hypermethylation in Liver Cancer: Diagnostic and Clinical Significance

AIM: Protocadherin-8 (PCDH8) plays an important role in signaling pathways of cell adhesin, proliferation, and migration. It has been reported that PCDH8 is mutated or methylated in several human cancers. However, little is known about PCDH8 in liver cancer. The aim of this study was to investigate the protein expression and promoter methylation status of PCDH8 in liver cancer and evaluate the association between PCDH8 methylation and the clinicopathological features.

METHODS: The methylation status of PCDH8 in 42 hepatocellular carcinoma (HCC), 8 Cholangiocarcinoma (CC) and 50 normal liver tissues were examined using methylation-specific PCR (MSP) and the protein expression of PCDH8 was detected by immunohistochemistry. The relationships between PCDH8 methylation and clinicopathological features as well as overall survival of patients were evaluated.

RESULTS: The PCDH8 methylation was more frequent in liver cancer tissues than that in the normal liver tissues (88% vs. 32%, P < 0.001), and is significantly associated with loss of its protein expression (P = 0.004). Moreover, there is a significant correlation between PCDH8 methylation and the alpha-fetoprotein (AFP) level (P = 0.008). Kaplan-Meier survival analysis revealed that patients with PCDH8 methylation have shorter OS and PFS than those without PCDH8 methylation (P = 0.041 and P = 0.028, respectively).

CONCLUSION: PCDH8 is often inactivated by promoter methylation in liver cancer. PCDH8 methylation can serve as a valuable diagnostic biomarker for early detection of liver cancer and might be useful to predict an unfavorable clinical feature.

Urothelial cancer gene regulatory networks inferred from large-scale RNAseq, Bead and Oligo gene expression data

BACKGROUND

Urothelial pathogenesis is a complex process driven by an underlying network of interconnected genes. The identification of novel genomic target regions and gene targets that drive urothelial carcinogenesis is crucial in order to improve our current limited understanding of urothelial cancer (UC) on the molecular level. The inference of genome-wide gene regulatory networks (GRN) from large-scale gene expression data provides a promising approach for a detailed investigation of the underlying network structure associated to urothelial carcinogenesis.

METHODS

In our study we inferred and compared three GRNs by the application of the BC3Net inference algorithm to large-scale transitional cell carcinoma gene expression data sets from Illumina RNAseq (179 samples), Illumina Bead arrays (165 samples) and Affymetrix Oligo microarrays (188 samples). We investigated the structural and functional properties of GRNs for the identification of molecular targets associated to urothelial cancer.

RESULTS

We found that the urothelial cancer (UC) GRNs show a significant enrichment of subnetworks that are associated with known cancer hallmarks including cell cycle, immune response, signaling, differentiation and translation. Interestingly, the most prominent subnetworks of co-located genes were found on chromosome regions 5q31.3 (RNAseq), 8q24.3 (Oligo) and 1q23.3 (Bead), which all represent known genomic regions frequently deregulated or aberated in urothelial cancer and other cancer types. Furthermore, the identified hub genes of the individual GRNs, e.g., HID1/DMC1 (tumor development), RNF17/TDRD4 (cancer antigen) and CYP4A11 (angiogenesis/ metastasis) are known cancer associated markers. The GRNs were highly dataset specific on the interaction level between individual genes, but showed large similarities on the biological function level represented by subnetworks. Remarkably, the RNAseq UC GRN showed twice the proportion of significant functional subnetworks. Based on our analysis of inferential and experimental networks the Bead UC GRN showed the lowest performance compared to the RNAseq and Oligo UC GRNs.

CONCLUSION

To our knowledge, this is the first study investigating genome-scale UC GRNs. RNAseq based gene expression data is the data platform of choice for a GRN inference. Our study offers new avenues for the identification of novel putative diagnostic targets for subsequent studies in bladder tumors.

Promoter methylation of protocadherin8 is an independent prognostic factor for biochemical recurrence of early-stage prostate cancer

BACKGROUND

Protocadherin8 has been demonstrated to play critical roles in initiation and progression of several human cancers. It is frequently inactivated by promoter methylation in cancers and may be used as a potential biomarker. However, the methylation status of protocadherin8 and its clinical significance in prostate cancer remains largely unknown. The purpose of this study was to evaluate the clinical significance of protocadherin8 methylation in early-stage prostate cancer.

MATERIAL AND METHODS

The promoter methylation status of protocadherin8 in 162 prostate cancer tissues and 47 normal prostate tissues was examined using methylation-specific PCR (MSP). Subsequently, the relationships between protocadherin8 methylation and clinicopathological features of prostate cancer patients and biochemical recurrence-free survival of patients were analyzed.

RESULTS

We found that protocadherin8 methylation occurred frequently in prostate cancer tissues but not in normal prostate tissues. Moreover, protocadherin8 methylation was significantly associated with advanced pathologic stage, higher level of preoperative prostate specific antigen (PSA), higher Gleason score, positive lymph node metastasis, and biochemical recurrence. In addition, patients with protocadherin8 methylated have shorter biochemical recurrence-free survival time than patients without. Multivariate Cox regression analysis revealed that protocadherin8 methylation was an independent predictor of biochemical recurrence-free survival in prostate cancer patients.

CONCLUSIONS

Promoter methylation of protocadherin8 is a frequent event in prostate cancer, and might be used as an independent prognostic factor for biochemical recurrence-free survival in patients with prostate cancer.

Aberrant methylation of PCDH8 is a potential prognostic biomarker for patients with clear cell renal cell carcinoma

BACKGROUND

PCDH8 is a tumor suppressor that regulates cell adhesin, proliferation, and migration. It is often inactivated by aberrant promoter methylation in several human cancers, including clear cell renal cell carcinoma (CCRCC). The clinical significance of PCDH8 methylation in CCRCC remains unclear. The aim of this study was to investigate the relationship between PCDH8 methylation and clinicopathological characteristics as well as outcome of patients with CCRCC.

MATERIAL/METHODS

The methylation status of PCDH8 in 153 CCRCC tissues and 97 paired adjacent normal renal tissues were examined using methylation-specific PCR (MSP). Then the relationships between PCDH8 methylation and clinicopathological features as well as progression-free survival of CCRCC patients were evaluated.

RESULTS

PCDH8 methylation was significantly more frequent in CCRCC tissues compared with normal renal tissues. Moreover, PCDH8 methylation was significantly correlated with advanced clinical stage (P=0.0141), higher grade (P=0.0190), and lymph node metastasis (P=0.0098). In addition, multivariate analysis showed that PCDH8 methylation was independently associated with poor progression-free survival (P=0.0316).

CONCLUSIONS

PCDH8 methylation is a frequent event in CCRCC and is correlated with unfavorable clinicopathological features. Moreover, PCDH8 methylation may be a useful biomarker to predict the progression of CCRCC.

Clinical significance of protocadherin 8 (PCDH8) promoter methylation in non-muscle invasive bladder cancer

Background

PCDH8 is a novel tumor suppressor gene, and frequently inactivated by promoter methylation in human cancers. However, there is little information regarding PCDH8 methylation in non-muscle invasive bladder cancer (NMIBC). The aim of this study was to investigate the methylation status of PCDH8 in NMIBC and its clinical significance.

Methods

The methylation status of PCDH8 in 233 NMIBC tissues and 43 normal bladder epithelial tissues was examined by methylation-specific PCR (MSP), and then analyzed the correlations between PCDH8 methylation and clinicopatholocial features. Subsequently, Kaplan-Meier survival analysis and Multivariate Cox proportional hazard model analysis was used to investigate the correlation between PCDH8 methylation and prognosis of patients with NMIBC.

Results

PCDH8 methylation occurred frequently in NMIBC tissues than those in normal bladder epithelial tissues. In addition, PCDH8 methylation significantly correlated with advanced stage, high grade, larger tumor size, tumor recurrence and progression in NMIBC. Kaplan-Meier survival analysis revealed that patients with PCDH8 methylated have shorter recurrence-free survival, progression-free survival and five-year overall survival than patients with PCDH8 unmethylated. Multivariate analysis suggested that PCDH8 methylation was an independent prognostic biomarker for recurrence-free survival, progression-free survival and five-year overall survival simultaneously.

Conclusions

PCDH8 methylation may be associated with tumor progression and poor prognosis in NMIBC and may be used as a potential biomarker to predict the prognosis of patients with NMIBC.

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.

Protocadherin 17 promoter methylation in tumour tissue from patients with bladder transitional cell carcinoma

OBJECTIVE

To investigate the clinical significance of protocadherin 17 (PCDH17) promoter methylation in bladder cancer.

METHODS

Methylation-specific polymerase chain reaction was used to examine the promoter methylation status of PCDH17 in tumour tissue specimens obtained from patients with bladder cancer, and in normal bladder epithelial tissue specimens obtained from age- and sex-matched controls. The correlations between methylation status and demographic and clinicopathological parameters, and disease outcome, were assessed.

RESULTS

Methylation of the PCDH17 promoter was detected in 77/115 (67.0%) patients with bladder cancer and 0/43 (0%) of the controls. Methylation was significantly associated with high cancer grade (G3), advanced cancer stage (T2-T4), large tumour diameter (> 3 cm) and tumour recurrence. Methylation was also associated with significantly shorter survival time compared with unmethylated PCDH17 in patients with bladder cancer, and was an independent predictor of overall survival.

CONCLUSIONS

PCDH17 promoter methylation is closely associated with bladder cancer malignancy and may be used as an independent predictor of clinical outcomes in patients with bladder cancer.