DNA Methylation profiles as predictors of recurrence in non muscle invasive bladder cancer: an MS-MLPA approach

Identification and Validation of a Prognostic Signature Based on Methylation Profiles and Methylation-Driven Gene DAB2 as a Prognostic Biomarker in Differentiated Thyroid Carcinoma

Recurrence is the major death cause of differentiated thyroid carcinoma (DTC), and a better understanding of recurrence risk at early stage may lead to make the optimal medical decision to improve patients’ prognosis. The 2015 American Thyroid Association (ATA) risk stratification system primary based on clinic-pathologic features is the most commonly used to describe the initial risk of persistent/recurrent disease. Besides, multiple prognostics models based on multigenes expression profiles have been developed to predict the recurrence risk of DTC patients. Recent evidences indicated that aberrant DNA methylation is involved in the initiation and progression of DTC and can be useful biomarkers for clinical diagnosis and prognosis prediction of DTC. Therefore, there is a need for integrating gene methylation feature to assess the recurrence risk of DTC. Gene methylation profile from The Cancer Genome Atlas (TCGA) was used to construct a recurrence risk model of DTC by successively performed univariate Cox regression, LASSO regression, and multivariate Cox regression. Two Gene Expression Omnibus (GEO) methylation cohorts of DTC were utilized to validate the predictive value of the methylation profiles model as external cohort by receiver operating characteristic (ROC) curve and survival analysis. Besides, CCK-8, colony-formation assay, transwell, and scratch-wound assay were used to investigate the biological significance of critical gene in the model. In our study, we constructed and validated a prognostic signature based on methylation profiles of SPTA1, APCS, and DAB2 and constructed a nomogram based on the methylation-related model, age, and AJCC_T stage that could provide evidence for the long-term treatment and management of DTC patients. Besides, in vitro experiments showed that DAB2 inhibited proliferation, colony-formation, and migration of BCPAP cells and the gene set enrichment analysis and immune infiltration analysis showed that DAB2 may promote antitumor immunity in DTC. In conclusion, promoter hypermethylation and loss expression of DAB2 in DTC may be a biomarker of unfavorable prognosis and poor response to immune therapy.

Matched Paired Primary and Recurrent Meningiomas Points to Cell-Death Program Contributions to Genomic and Epigenomic Instability along Tumor Progression

Meningioma (MN) is an important cause of disability, and predictive tools for estimating the risk of recurrence are still scarce. The need for objective and cost-effective techniques addressed to this purpose is well known. In this study, we present methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) as a friendly method for deepening the understanding of the mechanisms underlying meningioma progression. A large follow-up allowed us to obtain 50 samples, which included the primary tumor of 20 patients in which half of them are suffering one recurrence and the other half are suffering more than one. We histologically characterized the samples and performed MS-MLPA assays validated by FISH to assess their copy number alterations (CNA) and epigenetic status. Interestingly, we determined the increase in tumor instability with higher values of CNA during the progression accompanied by an increase in epigenetic damage. We also found a loss of HIC1 and the hypermethylation of CDKN2B and PTEN as independent prognostic markers. Comparison between grade 1 and higher primary MN's self-evolution pointed to a central role of GSTP1 in the first stages of the disease. Finally, a high rate of alterations in genes that are related to apoptosis and autophagy, such as DAPK1, PARK2, BCL2, FHIT, or VHL, underlines an important influence on cell-death programs through different pathways.

Improved urine DNA methylation panel for early bladder cancer detection

BACKGROUND

Bladder cancer is one of the most common malignancies but the corresponding diagnostic methods are either invasive or limited in specificity and/or sensitivity. This study aimed to develop a urine-based methylation panel for bladder cancer detection by improving published panels and validate performance of the new panel with clinical samples.

METHODS

Related researches were reviewed and 19 potential panels were selected. RRBS was performed on a cohort with 45 samples to reassess these panels and a new panel inherited best markers was developed. The new panel was applied with qMSP platform to 33 samples from the RRBS cohort and the results were compared to those of RRBS. Lastly, another larger cohort with 207 samples was used to validate new panel performance with qMSP.

RESULTS

Three biomarkers (PCDH17, POU4F2 and PENK) were selected to construct a new panel P3. P3 panel achieved 100% specificity and 71% sensitivity with RRBS in corresponding cohort and then showed a better performance of 100% specificity and 84% sensitivity with qMSP platforms in a balanced cohort. When validated with 207-sample cohort, P3 with qMSP showed a performance of 97% specificity and 87% sensitivity which was modestly improved compared to the panels it derided from.

CONCLUSIONS

Overall, the P3 panel achieved relatively high sensitivity and accuracy in bladder cancer detection.

Aberrant DNA Methylation in Bladder Cancer among Saudi Arabia Population

Tumor biomarkers developed based on the aberrant deoxyribonucleic acid (DNA) methylation patterns in bladder cancer (BC) hold great promise due to their stability, specificity, and known associations with the disease. No study has investigated DNA methylation patterns in BC patients from Saudi population. We analyzed DNA methylation levels of 48 tumor suppressor genes loci in 24 bladder tissues (19 BC and 5 control samples) using Human Tumour Suppressor Genes EpiTect Methyl II Complete PCR Array (Qiagen, Hilden, Germany). We identified significant difference in DNA hypermethylation levels at E2F1, ERBB2, HIC1, OPCML, SFN, SFRP1, SFRP2, SPARC, and TERT gene loci between controls and cancerous samples. SCGB3A1 was differentially methylated in nonmuscle invasive versus muscle invasive BC samples. Results suggest that these aberrant DNA methylation patterns in BC are disease and population specific and can be developed as distinct DNA methylation-based biomarkers for BC detection.

Methylation-Driven Genes Identified as Novel Prognostic Indicators for Thyroid Carcinoma

BACKGROUND

Aberrant DNA methylation plays an crucial role in tumorigenesis through regulating gene expression. Nevertheless, the exact role of methylation in the carcinogenesis of thyroid cancer and its association with prognosis remains unclear. The purpose of this study is to explore the DNA methylation-driven genes in thyroid cancer by integrative bioinformatics analysis.

METHODS

The transcriptome profiling data and DNA methylation data of thyroid cancer were downloaded from The Cancer Genome Atlas (TCGA) database. The methylmix R package was used to screen DNA methylation-driven genes in thyroid cancer. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were conducted to annotate the function of methylation-driven genes. Univariate Cox regression analyses was performed to distinguish prognosis-related methylation-driven genes. Multivariate Cox regression analyses was utilized to build a prognostic multi-gene signature. A survival analysis was carried out to determine the individual prognostic significance of this multi-gene signature.

RESULTS

A total of 51 methylation-driven genes were identified. The functional analysis indicated that these genes were significantly enriched in diverse biological processes (BP) and pathways related to the malignancy processes. Four of these genes (RDH5, TREM1, BIRC7, and SLC26A7) were selected to construct the risk evaluation model. Patients in the low-risk group had an conspicuously better overall survival (OS) than those in high-risk group (p < 0.001). The area under the receiver operating characteristic (ROC) curve for this model was 0.836, suggesting a good specificity and sensitivity. Subsequent survival analysis revealed that this four-gene signature served as an independent indicator for the prognosis of thyroid cancer. Moreover, the prognostic signature was well validated in a external thyroid cancer cohort.

CONCLUSION

We identified methylation-driven genes in thyroid cancer with independent prognostic value, which may offer new insight into molecular mechanisms of thyroid cancer and provide new possibility for individualized treatment of thyroid cancer patients.

Synergic effects of cancer stem cells markers, CD44 and embryonic stem cell transcription factor Nanog, on bladder cancer prognosis

Background: Therapy that targets cancer stem cells has the potential to eradicate cancer and prevent tumour recurrence. Therefore, we hypothesized the combined prognostic significance of stem cell markers CD44 (prevalent in basal layer of urothelial carcinoma) and Nanog (embryonic stem cell transcription factor) in bladder cancer.Material and Methods: CD44 and Nanog expression were determined by immunohistochemistry in 112 bladder cancer cases of which 79 were non-muscle invasive and 33 muscle invasive.Results: A significant correlation was found between CD44 and Nanog expression (r = 0.41, p < 0.001). The bladder cancer patients with high CD44 and Nanog expression had poor recurrence-free survival and poor overall survival (all p < 0.01). Multivariate Cox regression analysis identified lymph node positivity (hazard ratio; HR 3.81, 95% confidence interval; CI 1.66-8.75), CD44 (HR/95%CI 7.03 [3.04-16.22]) and Nanog (HR/95%CI 2.89 [1.23-6.77]) as independent prognostic biomarkers for recurrence-free survival, whilst a combined index of CD44 and Nanog expression (high expression group; HR/95%CI 25.45 [6.71-96.50] for recurrence-free survival) and lymph node positivity (HR/95%CI 3.68 [1.63-8.33] for recurrence-free survival) were independent prognostic biomarkers for recurrence-free survival and overall survival (all p < 0.001).Conclusions: A combined index of CD44 and Nanog expression is a promising prognostic predictor of recurrence-free survival and overall survival in bladder cancer. It may help identification of patients who will benefit from intensive treatment.

A six-gene prognostic model predicts overall survival in bladder cancer patients

Background

The fatality and recurrence rates of bladder cancer (BC) have progressively increased. DNA methylation is an influential regulator associated with gene transcription in the pathogenesis of BC. We describe a comprehensive epigenetic study performed to analyse DNA methylation-driven genes in BC.

Methods

Data related to DNA methylation, the gene transcriptome and survival in BC were downloaded from The Cancer Genome Atlas (TCGA). MethylMix was used to detect BC-specific hyper-/hypo-methylated genes. Metascape was used to carry out gene ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. A least absolute shrinkage and selection operator (LASSO)-penalized Cox regression was conducted to identify the characteristic dimension decrease and distinguish prognosis-related methylation-driven genes. Subsequently, we developed a six-gene risk evaluation model and a novel prognosis-related nomogram to predict overall survival (OS). A survival analysis was carried out to explore the individual prognostic significance of the six genes.

Results

In total, 167 methylation-driven genes were identified. Based on the LASSO Cox regression, six genes, i.e., ARHGDIB, LINC00526, IDH2, ARL14, GSTM2, and LURAP1, were selected for the development of a risk evaluation model. The Kaplan–Meier curve indicated that patients in the low-risk group had considerably better OS (P = 1.679e−05). The area under the curve (AUC) of this model was 0.698 at 3 years of OS. The verification performed in subgroups demonstrated the validity of the model. Then, we designed an OS-associated nomogram that included the risk score and clinical factors. The concordance index of the nomogram was 0.694. The methylation levels of IDH2 and ARL14 were appreciably related to the survival results. In addition, the methylation and gene expression-matched survival analysis revealed that ARHGDIB and ARL14 could be used as independent prognostic indicators. Among the six genes, 6 methylation sites in ARHGDIB, 3 in GSTM2, 1 in ARL14, 2 in LINC00526 and 2 in LURAP1 were meaningfully associated with BC prognosis. In addition, several abnormal methylated sites were identified as linked to gene expression.

Conclusion

We discovered differential methylation in BC patients with better and worse survival and provided a risk evaluation model by merging six gene markers with clinical characteristics.

GSTP1 methylation in cancer: a liquid biopsy biomarker?

The coding region of GSTP1 gene is preceded by a large CpG-rich region that is frequently affected by methylation. In many cancer types, GSTP1 is affected by hypermethylation and, as a consequence, it has a low expression. The aim of this review is to give an overview on GSTP1 methylation studies with a special focus on liquid biopsy, thus to summarize methods, results, sample types, different diseases, to have a complete information regarding this promising epigenetic biomarker. We used all the most valuable scientific search engines (PubMed, Medline, Scopus and Web of Science) searching the following keywords: GSTP1, methylation, cancer, urine, serum, plasma and blood. GSTP1 is a largely investigated tissue biomarker in several malignancies such as prostate, breast, lung and hepatocellular carcinoma with good performances especially for diagnostic purposes. As a liquid biopsy biomarker, it has been mainly investigated in prostate cancer (PCa) where it showed a high specificity but a low sensitivity; thus, it is recommended in combination with other biomarkers. Despite the large number of published papers and the promising results, GSTP1 has not yet entered the clinical practice even for PCa diagnosis. For this reason, further large and prospective studies are needed to validate this assay.

Lost expression of cell adhesion molecule 1 is associated with bladder cancer progression and recurrence and its overexpression inhibited tumor cell malignant behaviors

Cell adhesion molecule 1 (CADM1) regulates cell-cell adhesion and an altered expression level is associated with tumorigenesis and progression. The present study assessed CADM1 expression level in 84 bladder tissues to investigate the association with clinicopathological parameters from bladder cancer patients and then investigated the effects of CADM1 overexpression on T24 bladder cancer cells in vitro. The results demonstrated that expression level of CADM1 protein was significantly reduced in bladder cancer tissues (0.26±0.14) compared with in normal bladder mucosa (0.69±0.092; P<0.01), and methylation of CADM1 promoter was responsible for silencing of CADM1 protein expression and significantly associated with tumor size, recurrence, pathology classification and clinical stage (P<0.05). Overexpression of CADM1 protein inhibited tumor cell proliferation, reduced tumor cell invasion capacity and induced tumor cell apoptosis in vitro. At the gene level, CADM1 expression level upregulated caspase-3 activity and expression of Bax and p27 protein and downregulated levels of B cell lymphoma-2, cyclinD1, cyclinE1 and cyclin dependent kinase 2 proteins. Furthermore, overexpression of CADM1 regulated the expression level of epithelial to mesenchymal transition markers, including increased expression level of E-cadherin and β-catenin, whereas it decreased the levels of Vimentin. The present study demonstrated that lost expression of CADM1 protein may exert an essential role in the development and progression of bladder cancer and suggested that CADM1 may be a novel molecular target for the control of this disease in clinical practice.

NOTCH1 regulates the proliferation and migration of bladder cancer cells by cooperating with long non-coding RNA HCG18 and microRNA-34c-5p

In recent years, the NOTCH signaling pathway has been gradually studied in human malignancies. Inactivation of the NOTCH signaling pathway was uncovered to be correlated with the carcinogenesis of bladder cancer (BCa). Nevertheless, the specific molecular mechanism of NOTCH1 (one of the core factors of the NOTCH signaling pathway) is not well elucidated in BCa. This study focused on the mechanism by which NOTCH1 affects the biological behaviors of BCa cells. According to the experimental results of quantitative real-time polymerase chain reaction, NOTCH1 was dysregulated in BCa tissues and cell lines. The prognostic value of NOTCH1 for the patients with BCa was determined using the Kaplan-Meier method. Mechanism investigations revealed that NOTCH1 is a target of miR-34c-5p in BCa. Furthermore, microarray analysis was used to find the dysregulated long noncoding RNAs (lncRNA), which can bind with miR-34c-5p. Mechanism experiments further demonstrated the rationality of the HCG18-miR-34c-5p-NOTCH1 pathway. Functional assays were then applied to validate the inhibitory influences of NOTCH1 on the proliferation and migration of BCa cells. Furthermore, the inhibitory effects of NOTCH1 could be affected by miR-34c-5p or lncRNA HCG18. All findings in this study revealed that NOTCH1 suppresses the BCa progression by cooperating with lncRNA HCG18 and miR-34c-5p.

Long non-coding RNA ARAP1-AS1 promotes the progression of bladder cancer by regulating miR-4735-3p/NOTCH2 axis

Accumulative reports have documented the critical functions of long non-coding RNAs (lncRNAs) in the progression of malignant tumors, including bladder cancer (BCa). LncRNA ARAP1-AS1 was chosen to be the object of this study due to it was significantly upregulated in the BCa samples of TCGA database. qRT-PCR further validated the dysregulation of ARAP1-AS1 in 88 pairs of BCa tissues and six BCa cells. Kaplan Meier analysis was utilized to analyze the prognostic value of ARAP1-AS1 for patients with BCa. To evaluate the oncogenic property of ARAP1-AS1 in bladder cancer, loss-of-function assays were conducted in two BCa cells in which ARAP1-AS1 was expressed highest. Mechanically, ARAP1-AS1 was enriched in the cytoplasm of BCa cells, suggesting that ARAP1-AS1 might act as a ceRNA to regulate gene expression and biological processes in bladder cancer. It was certified that ARAP1-AS1 can bind with miR-4735-3p in BCa cells. Moreover, functional assays supported the hypothesis that miR-4735-3p is a tumor suppressor in BCa. Additionally, NOTCH2 mRNA could be targeted by miR-4735-3p in BCa cells. The results of all mechanism experiments indicated that ARAP1-AS1 regulated miR-4735-3p/NOTCH2 axis in BCa by acting as a ceRNA. All our research findings may bring novel insights into the treatment of bladder cancer.

Epigenetic changes underlie the aggressiveness of histologically benign meningiomas that recur

Meningiomas are the most frequent primary brain tumor. Usually, they are curable by surgery, but even after seemingly complete resection, some low-grade lesions recur. Despite recent improvements, signatures having prognostic value in grade I tumors remain poorly characterized. The frequency and delicate location of these tumors suggest that the risk of recurrence might be more accurately predicted. Herein, we show an easy way to evaluate the methylation status of meningiomas and its correlation with the prognosis of the disease. A series of 120 meningiomas, including primary tumors and recurrences, were analyzed histopathologically, and 24 tumor suppressor genes (TSGs) were studied by methylation-specific multiple ligation probe amplification. Long-term follow-up was conducted to classify patients with grade I primary tumors according to their outcomes. We found that hypermethylation in at least one TSG is frequent. The number of hypermethylated TSG per case was significantly higher in recurrences than in primary tumors and in primary benign meningiomas that recurred than in tumors from patients who showed no evidence of disease during follow-up. Finally, hypermethylation in RASSF1A, MLH1, and CDKN2B was an independent prognostic factor associated with the time to recurrence of these benign tumors that were biologically aggressive. To our knowledge, this is one of the widest studies of primary grade I tumors of patients who developed a tumor recurrence. The frequency of epigenetic changes suggests that hypermethylation is an early event in meningiomas, whereas the accumulation of epigenetic changes is related to greater biological aggressiveness and may be a signature of potential clinical relevance.

Evaluation of glutathione S-transferase pi 1 expression and gene promoter methylation in Moroccan patients with urothelial bladder cancer

BACKGROUND

Glutathione S-transferase pi 1 (GSTP1) is a cytosolic detoxifying enzyme that protects cells against deleterious effects of oxidative stress. Deregulated expression of GSTP1 protein and aberrant promoter methylation of GSTP1 gene were reported in various human tumors and were shown to be involved in the molecular pathway for cancer development.

AIMS AND METHODS

In this study, we aimed to determine the expression status of GSTP1 in relation to its gene promoter methylation in Moroccan population of 30 bladder cancer (BC) patients and in two noncancerous bladder tissues used as controls. GSTP1 expression was assessed by immunohistochemistry and GSTP1 gene promoter methylation status was studied by methylation-specific PCR (MS-PCR).

RESULTS

Glutathione S-transferase pi 1 was expressed in the two normal tissues. In BC cases, GSTP1 expression was strong in 23.33% (7/30), moderate in 60% (18/30), and weak in 13.33% (4/30) of cases, while GSTP1 was not expressed in one cancer case (3.33%). Variability of GSTP1 expression does not correlate with high-grade cancer or invasive-stage (p > 0.05). No GSTP1 gene promoter methylation was detected in all control and cancer cases.

CONCLUSION

Our data suggest that GSTP1 expression is not associated with BC development, limiting its use as a biomarker for BC management in Morocco. Moreover, difference in GSTP1 expression among BC cases is not due to GSTP1 promoter methylation.

Methylation Profiles of BRCA1, RASSF1A and GSTP1 in Vietnamese Women with Breast Cancer

Objective: This study investigated the DNA promoter methylation profiles of BRCA1, RASSF1A and GSTP1 genes, both individually and in an integrative manner in order to clarify their correlation with clinicopathological parameters of breast cancer from Vietnamese patients, and establish new potential integrative methylation biomarkers for breast cancer detection. Material and methods: The methylation frequencies of BRCA1, RASSF1A and GSTP1 were analyzed by methylation specific polymerase chain reaction (MSP) in 70 specimens of breast carcinomas and 79 pairs of tumor and matched adjacent normal tissues from breast cancer patients. Results: All the three analyzed genes showed a concordance concerning their promoter methylation in tumor and adjacent normal tissue. The methylation of BRCA1, RASSF1A and GSTP1 was found in 58.23 %, 74.68 % and 59.49 % of tumor tissues and 51.90 %, 63.29 % and 35.44 % of corresponding adjacent tissues, respectively. When each gene was assessed individually, only the methylation of GSTP1 was significantly associated with tumor tissues (p=0.003). However, the methylation frequency of at least one of the three genes and the methylation frequency of all the three genes both showed significant association with tumor (p=0.008 and p=0.04, respectively). The methylation of BRCA1 was found to be significantly associated with tumor grade (p=0.01). Conclusion: This study emphasized that the panel of the three genes BRCA1, RASSF1A and GSTP1 can be further developed as potential biomarkers in diagnosis and classification of breast cancer in Vietnamese women.

Methylation profiles of miR34 gene family in Vietnamese patients suffering from breast and lung cancers

The three genes encoding small non‑coding microRNA (miR)34a, MIR34b and MIR34c act as tumor‑suppressor genes. Their aberrant expressions regulated by DNA methylation have been frequently found in various types of cancer. In the present study, the DNA promoter methylation profiles of the MIR34 gene family were analyzed using the methylation specific polymerase chain reaction in order to clarify their association with breast and lung cancer, non‑cancerous or normal adjacent tissues. The methylation frequency of MIR34a was significantly higher in breast cancer (49.37%) compared with normal adjacent tissues (30.38%). The methylation frequency of MIR34b/c was 59.49 and 62.03% in breast cancer and normal adjacent tissues, respectively. MIR34a methylation showed a significant concordance with that of MIR34b/c only in breast cancer tissue. MIR34a methylation was significantly associated with cancer and the invasive ductal carcinoma type of breast cancer (P=0.015 and P=0.02, respectively). Methylation frequency of MIR34a and MIR34b/c was 48.42 and 56.84% in lung cancer, and 47.22 and 51.39% in pulmonary diseases, respectively. No significant association was observed between the methylation status of MIR34a and MIR34b/c, and the clinicopathological features of lung cancer or with those of non‑cancerous pulmonary diseases. Promoter methylation of MIR34a and MIR34b/c occurs frequently and concomitantly in breast and lung cancer, as well as in pulmonary diseases tissues, but not in breast normal tissues adjacent to tumor. These results of the present study emphasize the involvement of MIR34 methylation in human diseases, including cancer. Furthermore, MIR34a methylation may be a promising marker for a subtype of breast cancer.

Predictive value of gene methylation for second recurrence following surgical treatment of first bladder recurrence of a primary upper-tract urothelial carcinoma

The clinical relevance of aberrant DNA promoter methylation is being increasingly recognized in urothelial carcinoma. The present study was conducted to explore the methylation status of patients with upper-tract urothelial carcinoma (UTUC) who experienced bladder recurrence, and to evaluate the predictive value of gene methylation for second bladder recurrence and tumor progression. A total of 85 patients with primary UTUC, who experienced bladder recurrence after radical nephroureterectomy, were enrolled between January 2001 and December 2013. Using methylation-sensitive polymerase chain reaction, the promoter methylation statuses of 10 genes were analyzed in the bladder tumor specimens. Among the patient group, 32 patients experienced second bladder recurrence, and bladder progression was detected in 16. With the exception of BRCA1, the methylation rate of the majority of genes tended to gradually increase to varying extents with the number of recurrences; a smaller proportion of primary tumors exhibited gene methylation when compared with the first recurrent tumors and second recurrent tumors. Univariate and multivariate Cox regression analyses revealed that unmethylated GDF15 [hazard ratio (HR)=0.36; 95% confidence interval (CI), 0.14-0.92] and methylated VIM (HR=2.91; 95% CI, 1.11-7.61) in the first recurrent bladder tumor, as well as male gender (HR=2.28; 95% CI, 1.06-4.87), first recurrence interval <8 months (HR=2.34; 95% CI, 1.15-4.78) and primary UTUC tumor size ≥5 cm (HR=3.48; 95% CI, 1.43-8.45) were independent risk factors for a second bladder recurrence after surgery for the first bladder recurrence; the Harrell's concordance index (c-index) for the related nomogram was 0.71 (95% CI: 0.61-0.81). Furthermore, methylated CDH1 (HR=2.91; 95% CI, 1.08-7.77) and VIM (HR=4.91; 95% CI, 1.11-21.7) in the first recurrent bladder tumor, male gender (HR=3.6; 95% CI, 1.1-11.73), and primary tumor stage T2-T4 (HR=4.57; 95% CI, 1.22-17.13), multifocality (HR=3.64; 95% CI, 1.19-11.16) and size ≥5 cm (HR=3.1; 95% CI, 1.91-10.54) for the primary UTUC were considered to be predictors of tumor progression; the c-index for the nomogram was 0.88 (95% CI, 0.69-0.92). The present findings demonstrated that promoter methylation of cancer-related genes was frequently observed in patients with urothelial carcinoma, and that the gene methylation rate of certain genes tended to gradually increase with the number of bladder recurrences. This may be used as a predictive factor for a second bladder recurrence and tumor progression after the surgical treatment of the first bladder recurrence.

Comparison of clinicopathologic characteristics, epigenetic biomarkers and prognosis between renal pelvic and ureteral tumors in upper tract urothelial carcinoma

Background

There's no consensus about the difference between renal pelvic and ureteral tumors in terms of clinical features, pathological outcomes, epigenetic biomarkers and prognosis.

Methods

The data of 341 patients with renal pelvic tumors and 271 patients with ureteral tumors who underwent radical nephroureterectomy between 1999 and 2011 were retrospectively reviewed. The clinicopathologic features, gene promoters methylation status and oncologic outcomes were compared. Regression analysis was performed to identify oncologic prognosticators.

Results

Patients with ureteral tumors were relatively older (p = 0.002), and had higher likelihood of pre-operative renal insufficiency (p < 0.001), hypertension (p = 0.038) and hydronephrosis (P < 0.001), while in patients with renal pelvic tumors gross hematuria was more prevalent (p < 0.001). Renal pelvic tumors tended to exhibit non-organ-confined disease (p = 0.004) and larger tumor diameter (p = 0.001), while ureteral tumors had a higher likelihood of exhibiting high grade (p < 0.001) and sessile architecture (p = 0.023). Hypermethylated gene promoters were significantly more prevalent in renal pelvic tumors (p < 0.001), specifically for TMEFF2, GDF15, RASSF1A, SALL3 and ABCC6 (all p < 0.05). Tumor location failed to independently predict cancer-specific survival, overall survival, intravesical or contralateral recurrence (all p > 0.05), while gene methylation status was demonstrated to be an independent prognostic factor.

Conclusion

Renal pelvic tumors and ureteral tumors exhibited significant differences in clinicopathologic characteristics and epigenetic biomarkers. Gene promoter methylation might be an important mechanism in explaining distinct tumor patterns and behaviors in UTUC.

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.

DNA Methylation and Urological Cancer, a Step Towards Personalized Medicine: Current and Future Prospects

Urologic malignancies are some of the commonest tumors often curable when diagnosed at early stage. However, accurate diagnostic markers and faithful predictors of prognosis are needed to avoid over-diagnosis leading to overtreatment. Many promising exploratory studies have identified epigenetic markers in urinary malignancies based on DNA methylation, histone modification and non-coding ribonucleic acid (ncRNA) expression that epigenetically regulate gene expression. We review and discuss the current state of development and the future potential of epigenetic biomarkers for more accurate and less invasive detection of urological cancer, tumor recurrence and progression of disease serving to establish diagnosis and monitor treatment efficacies. The specific clinical implications of such methylation tests on therapeutic decisions and patient outcome and current limitations are also discussed.

Long non-coding RNA HNF1A-AS1 promotes proliferation and suppresses apoptosis of bladder cancer cells through upregulating Bcl-2

Emerging evidences have indicated that long non-coding RNAs (lncRNAs) are pivotal regulators of tumor development and progression. HNF1A-AS1 (HNF1A antisense RNA 1, C12 or f27) is a novel long non-coding RNA that acts as a potential biomarker and is involved in development and progression of several cancers. Nevertheless, we know nothing about the clinical significance and molecular mechanism of HNF1A-AS1 in bladder cancer. In this study, we found that HNF1A-AS1 is significantly up-regulated in bladder cancer. Further experiments had demonstrated that silencing HNF1A-AS1 in bladder cancer cells could inhibit the proliferation and induce apoptosis. Mechanistically, we found down-regulated of HNF1A-AS1 increased the expression of miR-30b-5p and subsequently inhibited the expression of Bcl-2, in a ceRNA-dependent way. Moreover, knockdown of miR-30b-5p reversed cell proliferation inhibition and cell apoptosis induced by silencing HNF1A-AS1. In conclusions, we demonstrated that HNF1A-AS1 plays an important regulatory role in bladder cancer and shed new light on lncRNA-directed diagnostic and therapeutics in bladder cancer.

Methylation pattern analysis in prostate cancer tissue: identification of biomarkers using an MS-MLPA approach

Background

Epigenetic silencing mediated by CpG island methylation is a common feature of many cancers. Characterizing aberrant DNA methylation changes associated with prostate carcinogenesis could potentially identify a tumour-specific methylation pattern, facilitating the early diagnosis of prostate cancer. The objective of the study was to assess the methylation status of 40 tumour suppressor genes in prostate cancer and healthy prostatic tissues.

Methods

We used methylation specific-multiplex ligation probe amplification (MS-MLPA) assay in two independent case series (training and validation set). The training set comprised samples of prostate cancer tissue (n = 40), healthy prostatic tissue adjacent to the tumor (n = 26), and healthy non prostatic tissue (n = 23), for a total of 89 DNA samples; the validation set was composed of 40 prostate cancer tissue samples and their adjacent healthy prostatic tissue, for a total of 80 DNA samples. Methylation specific-polymerase chain reaction (MSP) was used to confirm the results obtained in the validation set.

Results

We identified five highly methylated genes in prostate cancer: GSTP1, RARB, RASSF1, SCGB3A1, CCND2 (P < 0.0001), with an area under the ROC curve varying between 0.89 (95 % CI 0.82–0.97) and 0.95 (95 % CI 0.90–1.00). Diagnostic accuracy ranged from 80 % (95 % CI 70–88) to 90 % (95 % CI 81–96). Moreover, a concordance rate ranging from 83 % (95 % CI 72–90) to 89 % (95 % CI 80–95) was observed between MS-MLPA and MSP.

Conclusions

Our preliminary results highlighted that hypermethylation of GSTP1, RARB, RASSF1, SCGB3A1 and CCND2 was highly tumour-specific in prostate cancer tissue.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-016-1014-6) contains supplementary material, which is available to authorized users.

GSTP1 Methylation and Protein Expression in Prostate Cancer: Diagnostic Implications

GSTP1 belongs to the GSTs family, a group of enzymes involved in detoxification of exogenous substances and it also plays an important role in cell cycle regulation. Its dysregulation correlates with a large variety of tumors, in particular with prostate cancer. We investigated GSTP1 methylation status with methylation specific PCR (MS-PCR) in prostate cancer (PCa) and in benign tissue of 56 prostatectomies. We also performed immunohistochemistry (IHC) so as to correlate gene methylation with gene silencing. GSTP1 appears methylated in PCa and not in healthy tissue; IHC confirmed that methylation leads to protein underexpression (p < 0.001). GSTP1 is highly expressed in basal cell layer and luminal cells in benign glands while in prostatic intraepithelial neoplasia (PIN) it stains only basal cell layer, whereas PCa glands are completely negative. We demonstrated that methylation leads to underexpression of GSTP1. The progressive loss of GSTP1 expression from healthy glands to PIN and to PCa glands underlines its involvement in early carcinogenesis.

Tumor Suppressor in Lung Cancer-1 Is a Prognostic Predictor for the Recurrence and Progression of Non-Muscle-Invasive Bladder Cancer

OBJECTIVE

To investigate the relationship between the expression of tumor suppressor in lung cancer-1 (TSLC1) and clinicopathological characteristics of patients with non-muscle-invasive bladder cancer (NMIBC) and evaluate the prognostic significance of TSLC1.

METHODS

TSLC1 expression in 241 specimens of NMIBC was examined by immunohistochemistry. The correlation between TSLC1 expression and clinicopathological characteristics was evaluated using the chi-square test. The prognostic significance of TSLC1 was analyzed by univariate, multivariate analysis and Kaplan-Meier survival curves.

RESULTS

The total negative rate of TSLC1 expression was 47.3% in NMIBC. Decreased expression of TSLC1 was correlated with a higher clinical stage, higher pathological grade, the number of tumors, lager tumor size, tumor recurrence and progression. TSLC1 expression was an independent risk factor for predicting tumor recurrence (p = 0.005) and progression (p < 0.001).

CONCLUSION

Decreased expression of TSLC1 is correlated with the malignancy of NMIBC tissues and low TSLC1 expression may serve as a predictor for bladder cancer recurrence and progression.

Prognostic and predictive value of epigenetic biomarkers and clinical factors in upper tract urothelial carcinoma

Aim: We conducted this study to identify gene promoter methylation status and clinical predictors for upper tract urothelial carcinoma (UTUC) patients. Materials & methods: Using methylation-sensitive PCR, we examined ten genes promoter methylation status in 687 UTUC patients. Results: A methylated promoter of three genes to predict higher tumor stage (T3 and T4), five genes to predict higher tumor grade (G3) and one gene to predict pN+ were certified in this study. Nine factors were significantly associated with poor cancer-specific survival. Six factors were considered as predictors to develop bladder recurrence after surgery. Conclusion: Methylation occurs commonly in UTUCs, may affect carcinogenic mechanisms, and is a well predictive factor for cancer-specific survival and bladder recurrence in UTUCs.

Differential role of gene hypermethylation in adenocarcinomas, squamous cell carcinomas and cervical intraepithelial lesions of the uterine cervix

Cervical cancer is the third most common cancer in women worldwide. The hypermethylation of P16, TSLC-1 and TSP-1 genes was analyzed in squamous cell carcinomas (SCC), cervical intraepithelial lesions (CIN) and adenocarcinomas (ADC) of the uterine cervix (total 181 lesions). Additionally human papillomavirus (HPV) type, EPB41L3, RASSF1 and RASSF2 hypermethylation were tested in ADC and the results were compared with those obtained previously by our group in SCC. P16, TSLC-1 and TSP-1 hypermethylation was more frequent in SCCs than in CINs. These percentages and the corresponding ones for EPB41L3, RASSF1 and RASSF2 genes were also higher in SCCs than in ADCs, except for P16. The presence of HPV in ADCs was lower than reported previously in SCC and CIN. Patients with RASSF1A hypermethylation showed significantly longer disease-free survival (P = 0.015) and overall survival periods (P = 0.009) in ADC patients. To our knowledge, this is the first description of the EPB41L3 and RASSF2 hypermethylation in ADCs. These results suggest that the involvement of DNA hypermethylation in cervical cancer varies depending on the histological type, which might contribute to explaining the different prognosis of patients with these types of tumors.

Molecular markers in bladder cancer: Novel research frontiers

Bladder cancer (BC) is a heterogeneous disease encompassing distinct biologic features that lead to extremely different clinical behaviors. In the last 20 years, great efforts have been made to predict disease outcome and response to treatment by developing risk assessment calculators based on multiple standard clinical-pathological factors, as well as by testing several molecular markers. Unfortunately, risk assessment calculators alone fail to accurately assess a single patient's prognosis and response to different treatment options. Several molecular markers easily assessable by routine immunohistochemical techniques hold promise for becoming widely available and cost-effective tools for a more reliable risk assessment, but none have yet entered routine clinical practice. Current research is therefore moving towards (i) identifying novel molecular markers; (ii) testing old and new markers in homogeneous patients' populations receiving homogeneous treatments; (iii) generating a multimarker panel that could be easily, and thus routinely, used in clinical practice; (iv) developing novel risk assessment tools, possibly combining standard clinical-pathological factors with molecular markers. This review analyses the emerging body of literature concerning novel biomarkers, ranging from genetic changes to altered expression of a huge variety of molecules, potentially involved in BC outcome and response to treatment. Findings suggest that some of these indicators, such as serum circulating tumor cells and tissue mitochondrial DNA, seem to be easily assessable and provide reliable information. Other markers, such as the phosphoinositide-3-kinase (PI3K)/AKT (serine-threonine kinase)/mTOR (mammalian target of rapamycin) pathway and epigenetic changes in DNA methylation seem to not only have prognostic/predictive value but also, most importantly, represent valuable therapeutic targets. Finally, there is increasing evidence that the development of novel risk assessment tools combining standard clinical-pathological factors with molecular markers represents a major quest in managing this poorly predictable disease.

Aberrant expression of the CHFR prophase checkpoint gene in human B-cell non-Hodgkin lymphoma

Checkpoint with FHA and Ring Finger (CHFR) is a checkpoint protein that reportedly initiates a cell cycle delay in response to microtubule stress during prophase in mitosis, which has become an interesting target for understanding cancer pathogenesis. Recently, aberrant methylation of the CHFR gene associated with gene silencing has been reported in several cancers. In the present study, we examined the expression of CHFR in B-cell non-Hodgkin lymphoma (B-NHL) in vitro and in vivo. Our results showed that the expression level of CHFR mRNA and protein was reduced in B-NHL tissue samples and B cell lines. Furthermore, CHFR methylation was detected in 39 of 122 B-NHL patients, which was not found in noncancerous reactive hyperplasia of lymph node (RH) tissues. CHFR methylation correlated with the reduced expression of CHFR, high International Prognostic Index (IPI) scores and later pathologic Ann Arbor stages of B-NHL. Treatment with demethylation reagent, 5-Aza-dC, could eliminate the hypermethylation of CHFR, enhance CHFR expression and cell apoptosis and inhibit the cell proliferation of Raji cells, which could be induced by high expression of CHFR in Raji cells. Our results indicated that aberrant methylation of CHFR may be associated with the pathogenesis, progression for B-NHL, which might be a novel molecular marker as prognosis and treatment for B-NHL.

Contralateral upper tract urothelial carcinoma after nephroureterectomy: the predictive role of DNA methylation

Background

Aberrant methylation of genes is one of the most common epigenetic modifications involved in the development of urothelial carcinoma. However, it is unknown the predictive role of methylation to contralateral new upper tract urothelial carcinoma (UTUC) after radical nephroureterectomy (RNU). We retrospectively investigated the predictive role of DNA methylation and other clinicopathological factors in the contralateral upper tract urothelial carcinoma (UTUC) recurrence after radical nephroureterectomy (RNU) in a large single-center cohort of patients.

Methods

In a retrospective design, methylation of 10 genes was analyzed on tumor specimens belonging to 664 consecutive patients treated by RNU for primary UTUC. Median follow-up was 48 mo (range: 3–144 mo). Gene methylation was accessed by methylation-sensitive polymerase chain reaction, and we calculated the methylation index (MI), a reflection of the extent of methylation. The log-rank test and Cox regression were used to identify the predictor of contralateral UTUC recurrence.

Results

Thirty (4.5%) patients developed a subsequent contralateral UTUC after a median follow-up time of 27.5 (range: 2–139) months. Promoter methylation for at least one gene promoter locus was present in 88.9% of UTUC. Fewer methylation and lower MI (P = 0.001) were seen in the tumors with contralateral UTUC recurrence than the tumors without contralateral recurrence. High MI (P = 0.007) was significantly correlated with poor cancer-specific survival. Multivariate analysis indicated that unmethylated RASSF1A (P = 0.039), lack of bladder recurrence prior to contralateral UTUC (P = 0.009), history of renal transplantation (P < 0.001), and preoperative renal insufficiency (P = 0.002) are independent risk factors for contralateral UTUC recurrence after RNU.

Conclusions

Our data suggest a potential role of DNA methylation in predicting contralateral UTUC recurrence after RNU. Such information could help identify patients at high risk of new contralateral UTUC recurrence after RNU who need close surveillance during follow up.

The functional role of long non-coding RNAs and epigenetics

Long non-coding RNAs (lncRNAs) are non-protein coding transcripts longer than 200 nucleotides. The post-transcriptional regulation is influenced by these lncRNAs by interfering with the microRNA pathways, involving in diverse cellular processes. The regulation of gene expression by lncRNAs at the epigenetic level, transcriptional and post-transcriptional level have been well known and widely studied. Recent recognition that lncRNAs make effects in many biological and pathological processes such as stem cell pluripotency, neurogenesis, oncogenesis and etc. This review will focus on the functional roles of lncRNAs in epigenetics and related research progress will be summarized.

MicroRNA-320c inhibits tumorous behaviors of bladder cancer by targeting Cyclin-dependent kinase 6

Background

Increasing evidence has suggested that dysregulation of microRNAs (miRNAs) could contribute to human disease including cancer. Previous miRNA microarray analysis illustrated that miR-320c is down-regulated in various cancers. However, the roles of miR-320c in human bladder cancer have not been well elucidated. Therefore, this study was performed to investigate the biological functions and molecular mechanisms of miR-320c in human bladder cancer cell lines, discussing whether it could be a therapeutic biomarker of bladder cancer in the future.

Methods

Two human bladder cancer cell lines and samples from thirteen patients with bladder cancer were analyzed for the expression of miR-320c by quantitative RT-PCR. Over-expression of miR-320c was established by transfecting mimics into T24 and UM-UC-3. Cell proliferation and cell cycle were assessed by cell viability assay, flow cytometry and colony formation assay. Cell motility ability was evaluated by transwell assay. The target gene of miR-320c was determined by luciferase assay, quantitative RT-PCR and western blot. The regulation of cell cycle and mobility by miR-320c was analyzed by western blot.

Results

We observed that miR-320c was down-regulated in human bladder cancer tissues and bladder cancer cell lines T24 and UM-UC-3. Over-expression of miR-320c could induce G1 phase arrest in UM-UC-3 and T24 cells, and subsequently inhibited cell growth. We also indentified miR-320c could impair UM-UC-3 and T24 cell motility. In addition, we identified CDK6, a cell cycle regulator, as a novel target of miR-320c. Moreover, we demonstrated miR-320c could induce bladder cancer cell cycle arrest and mobility via regulating CDK6. We also observed that inhibition of miR-320c or restoration of CDK6 in miR-320c-over-expressed bladder cancer cells partly reversed the suppressive effects of miR-320c.

Conclusions

miR-320c could inhibit the proliferation, migration and invasion of bladder cancer cells via regulating CDK6. Our study revealed that miR-320c could be a therapeutic biomarker of bladder cancer in the future.

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.

Promoter methylation of tumor suppressor genes in pre-neoplastic lesions; potential marker of disease recurrence

BACKGROUND

Epigenetic alterations of specific genes have been reported to be related to colorectal cancer (CRC) transformation and would also appear to be involved in the early stages of colorectal carcinogenesis. Little data are available on the role of these alterations in determining a different risk of colorectal lesion recurrence. The aim of the present study was to verify whether epigenetic alterations present in pre-neoplastic colorectal lesions detected by colonoscopy can predict disease recurrence.

METHODS

A retrospective series of 78 adenomas were collected and classified as low (35) or high-risk (43) for recurrence according to National Comprehensive Cancer Network guidelines. Methylation alterations were analyzed by the methylation-specific multiplex ligation probe assay (MS-MLPA) which is capable of quantifying methylation levels simultaneously in 24 different gene promoters. MS-MLPA results were confirmed by pyrosequencing and immunohistochemistry.

RESULTS

Higher levels of methylation were associated with disease recurrence. In particular, MLH1, ATM and FHIT gene promoters were found to be significantly hypermethylated in recurring adenomas. Unconditional logistic regression analysis used to evaluate the relative risk (RR) of recurrence showed that FHIT and MLH1 were independent variables with an RR of 35.30 (95% CI 4.15-300.06, P = 0.001) and 17.68 (95% CI 1.91-163.54, P = 0.011), respectively.

CONCLUSIONS

Histopathological classification does not permit an accurate evaluation of the risk of recurrence of colorectal lesions. Conversely, results from our methylation analysis suggest that a classification based on molecular parameters could help to define the mechanisms involved in carcinogenesis and prove an effective method for identifying patients at high risk of recurrence.

Copy number analysis of 24 oncogenes: MDM4 identified as a putative marker for low recurrence risk in non muscle invasive bladder cancer

Patients with non-muscle invasive bladder cancer (NMIBC) generally have a high risk of relapsing locally after primary tumor resection. The search for new predictive markers of local recurrence thus represents an important goal for the management of this disease. We studied the copy number variations (CNVs) of 24 oncogenes (MDM4, MYCN, ALK, PDGFRA, KIT, KDR, DHFR, EGFR, MET, SMO, FGFR1, MYC, ABL1, RET, CCND1, CCND2, CDK4, MDM2, AURKB, ERBB2, TOP2A, AURKA, AR and BRAF) using multiplex ligation probe amplification technique to verify their role as predictive markers of recurrence. Formalin-fixed paraffin-embedded tissue samples from 43 patients who underwent transurethral resection of the bladder (TURB) were used; 23 patients had relapsed and 20 were disease-free after 5 years. Amplification frequencies were analyzed for all genes and MDM4 was the only gene that showed significantly higher amplification in non recurrent patients than in recurrent ones (0.65 vs. 0.3; Fisher’s test p = 0.023). Recurrence-free survival analysis confirmed the predictive role of MDM4 (log-rank test p = 0.041). Our preliminary results indicate a putative role for the MDM4 gene in predicting local recurrence of bladder cancer. Confirmation of this hypothesis is needed in a larger cohort of NMIBC patients.

Urotensin II receptor determines prognosis of bladder cancer regulating cell motility/invasion

Background

Non Muscle Invasive Bladder Transitional Cancer (NMIBC) and Muscle Invasive Bladder Transitional Cancer (MIBC)/invasive have different gene profile and clinical course. NMIBC prognosis is not completely predictable, since the relapse rate is higher than 20%, even in the form of MIBC. The aim of this study is to evaluate if UTR expression can discriminate between NMIBC and MIBC and predict the risk of relapses in NMIBCs.

Methods

We have investigated upon urotensin-II (UII) receptor (UTR) expression in vivo in 159 patients affected by NMIBC. The biological role of UTR was also investigated in vitro. UTR expression was evaluated in a tissue-micro-array, consisting of normal, NMIBC and invasive bTCC samples.

Results

UTR discriminated between NMIBC and MIBC and showed a significant correlation between low UTR expression and shorter disease free survival in NMIBC. The superagonist UPG84 induced growth suppression at nM concentrations on 3/4 cell lines. Bladder cancer cell treatment with the antagonist urantide or the knock-down of UTR with a specific shRNA significantly blocked both the motility and invasion of bladder cancer cells.

Conclusions

The evaluation of UTR expression can discriminate between NMIBC at high and low risk of relapse. Moreover, our data suggest that UTR is involved in the regulation of motility, invasion and proliferation of bladder cancer cells. High UTR expression is an independent prognostic factor of good prognosis for NMIBC regulating motility and invasion of bladder cancer cells.

Inactivation of miR-34a by aberrant CpG methylation in Kazakh patients with esophageal carcinoma

Background

Esophageal squamous cell carcinoma (ESCC) is an aggressive tumor with dismal prognosis and high incidence and mortality in Kazakh population. MiR-34a, a direct p53 target gene, possesses tumor-suppressive properties as they mediate apoptosis, cell cycle arrest, and senescence. The reduced expression of miR-34a by methylation in various cancers has been reported.

Methods

To determine whether aberrant miR-34a methylation occurs in esophageal cancer, the DNA methylation of 23 CpGs sites in the miR-34a promoter was quantitatively analyzed in relation to the translation initiation site by MALDI -TOF mass spectrometry in 59 ESCC tissues and 34 normal tissues from the Kazakh population. Real-time PCR was used to detect the inhibition of miR-34a expression levels and to evaluate their association with methylation.

Results

We found that miR-34a is more frequently methylated in ESCC (0.133 ± 0.040) than in controls (0.066 ± 0.045, P < 0.01). A nearly two-fold increase in miR-34a expression for the hypomethylated promoter was found in normal esophageal tissues than ESCC with hypermethylation (P <0.0001), pointing to a negative relationship between miR-34a CpG sites methylation and expression(r = −0.594, P = 0.042). The hypermethylation of miR-34a CpG_8.9 was associated with the advanced UICC stage III/IV of the esophageal cancers, and the hypermethylation of CpG_8.9 and CpG_5 of miR-34a was significantly correlated with lymph node metastasis.

Conclusions

Our findings suggest that miR-34a is involved in the etiology of ESCC and that hypermethylated miR-34a is a potential biomarker for ESCC diagnosis and prognosis. Moreover, targeting miR-34a methylation by demethylating agents may offer a novel strategy for anticancer therapy of ESCC.