European genome-wide association study identifies SLC14A1 as a new urinary bladder cancer susceptibility gene

SLC14A1 and TGF-β signaling: a feedback loop driving EMT and colorectal cancer metachronous liver metastasis

BACKGROUND

Colorectal cancer (CRC) metachronous liver metastasis is a significant clinical challenge, largely attributable to the late detection and the intricate molecular mechanisms that remain poorly understood. This study aims to elucidate the role of Solute Carrier Family 14 Member 1 (SLC14A1) in the pathogenesis and progression of CRC metachronous liver metastasis.

METHODS

We conducted a comprehensive analysis of CRC patient data from The Cancer Genome Atlas and GSE40967 databases, focusing on the differential expression of genes associated with non-metachronous liver metastasis and metachronous liver metastasis. Functional assays, both in vitro and in vivo, were performed to assess the biological impact of SLC14A1 modulation in CRC cells. Gene set enrichment analysis, molecular assays and immunohistochemical analyses on clinical specimens were employed to unravel the underlying mechanisms through which SLC14A1 exerts its effects.

RESULTS

SLC14A1 was identified as a differentially expressed gene, with its overexpression significantly correlating with poor relapse-free and overall survival. Mechanistically, elevated SLC14A1 levels enhanced CRC cell invasiveness and migratory abilities, corroborated by upregulated TGF-β/Smad signaling and Epithelial-Mesenchymal Transition. SLC14A1 interacted with TβRII and stabilized TβRII protein, impeding its Smurf1-mediated K48-linked ubiquitination and degradation, amplifying TGF-β/Smad signaling. Furthermore, TGF-β1 reciprocally elevated SLC14A1 mRNA expression, with Snail identified as a transcriptional regulator, binding downstream of SLC14A1's transcription start site, establishing a positive feedback loop. Clinically, SLC14A1, phosphorylated Smad2, and Snail were markedly upregulated in CRC patients with metachronous liver metastasis, underscoring their potential as prognostic markers.

CONCLUSIONS

Our findings unveil SLC14A1 as a critical regulator in CRC metachronous liver metastasis, providing novel insights into the molecular crosstalk between SLC14A1 and TGF-β/Smad signaling. These discoveries not only enhance our understanding of CRC metachronous liver metastasis pathogenesis, but also highlight SLC14A1 as a promising target for therapeutic intervention and predictive marker.

Computational exploration of SLC14A1 genetic variants through structure modeling, protein-ligand docking, and molecular dynamics simulation

The urea transporter UT-B1, encoded by the SLC14A1 gene, has been hypothesized to be a significant protein whose deficiency and dysfunction contribute to the pathogenesis of bladder cancer and many other diseases. Several studies reported the association of genetic alterations in the SLC14A1 (UT-B1) gene with bladder carcinogenesis, suggesting a need for thorough characterization of the UT-B1 protein's coding and non-coding variants. This study used various computational techniques to investigate the commonly occurring germ-line missense and non-coding SNPs (ncSNPs) of the SLC14A1 gene (UT-B1) for their structural, functional, and molecular implications for disease susceptibility and dysfunctionality. SLC14A1 missense variants, primarily identified from the ENSEMBL genome browser, were screened through twelve functionality prediction tools leading to two variants D280Y (predicted detrimental by maximum tools) and D280N (high global MAF) for rs1058396. Subsequently, the ConSurf and NetSurf tools revealed the D280 residue to be in a variable site and exposed on the protein surface. According to I-Mutant2.0 and MUpro, both variants are predicted to cause a significant effect on protein stability. Analysis of molecular docking anticipated these two variants to decrease the binding affinity of UT-B1 protein for the examined ligands to a significant extent. Molecular dynamics also disclosed the possible destabilization of the UT-B1 protein due to single nucleotide polymorphism compared to wild-type protein which may result in impaired protein function. Furthermore, several non-coding SNPs were estimated to affect transcription factor binding and regulation of SLC14A1 gene expression. Additionally, two ncSNPs were found to affect miRNA-based post-transcriptional regulation by creating new seed regions for miRNA binding. This comprehensive in-silico study of SLC14A1 gene variants may serve as a springboard for future large-scale investigations examining SLC14A1 polymorphisms.

Evaluating interactions of polygenic risk scores and NAT2 genotypes with tobacco smoking in bladder cancer risk

Tobacco smoking is the most important risk factor for bladder cancer. Previous studies have identified the N-acetyltransferase (NAT2) gene in association with bladder cancer risk. The NAT2 gene encodes an enzyme that metabolizes aromatic amines, carcinogens commonly found in tobacco smoke. In our study, we evaluated potential interactions of tobacco smoking with NAT2 genotypes and polygenic risk score (PRS) for bladder cancer, using data from the UK Biobank, a large prospective cohort study. We used Cox proportional hazards models to measure the strength of the association. The PRS was derived using genetic risk variants identified by genome-wide association studies for bladder cancer. With an average of 10.1 years of follow-up of 390 678 eligible participants of European descent, 769 incident bladder cancer cases were identified. Current smokers with a PRS in the highest tertile had a higher risk of developing bladder cancer (HR: 6.45, 95% CI: 4.51-9.24) than current smokers with a PRS in the lowest tertile (HR: 2.41, 95% CI: 1.52-3.84; P for additive interaction = <.001). A similar interaction was found for genetically predicted metabolizing NAT2 phenotype and tobacco smoking where current smokers with the slow NAT2 phenotype had an increased risk of developing bladder cancer (HR: 5.70, 95% CI: 2.64-12.30) than current smokers with the fast NAT2 phenotype (HR: 3.61, 95% CI: 1.14-11.37; P for additive interaction = .100). Our study provides support for considering both genetic and lifestyle risk factors in developing prevention measures for bladder cancer.

Genetic Polymorphisms Involved in Bladder Cancer: A Global Review

Bladder cancer (BC) has been associated with genetic susceptibility. Single peptide polymorphisms (SNPs) can modulate BC susceptibility. A literature search was performed covering the period between January 2000 and October 2020. Overall, 334 articles were selected, reporting 455 SNPs located in 244 genes. The selected 455 SNPs were further investigated. All SNPs that were associated with smoking and environmental exposure were excluded from this study. A total of 197 genes and 343 SNPs were found to be associated with BC, among which 177 genes and 291 SNPs had congruent results across all available studies. These genes and SNPs were classified into eight different categories according to their function.

Design and quality control of large-scale two-sample Mendelian randomization studies

Background

Mendelian randomization (MR) studies are susceptible to metadata errors (e.g. incorrect specification of the effect allele column) and other analytical issues that can introduce substantial bias into analyses. We developed a quality control (QC) pipeline for the Fatty Acids in Cancer Mendelian Randomization Collaboration (FAMRC) that can be used to identify and correct for such errors.

Methods

We collated summary association statistics from fatty acid and cancer genome-wide association studies (GWAS) and subjected the collated data to a comprehensive QC pipeline. We identified metadata errors through comparison of study-specific statistics to external reference data sets (the National Human Genome Research Institute-European Bioinformatics Institute GWAS catalogue and 1000 genome super populations) and other analytical issues through comparison of reported to expected genetic effect sizes. Comparisons were based on three sets of genetic variants: (i) GWAS hits for fatty acids, (ii) GWAS hits for cancer and (iii) a 1000 genomes reference set.

Results

We collated summary data from 6 fatty acid and 54 cancer GWAS. Metadata errors and analytical issues with the potential to introduce substantial bias were identified in seven studies (11.6%). After resolving metadata errors and analytical issues, we created a data set of 219 842 genetic associations with 90 cancer types, generated in analyses of 566 665 cancer cases and 1 622 374 controls.

Conclusions

In this large MR collaboration, 11.6% of included studies were affected by a substantial metadata error or analytical issue. By increasing the integrity of collated summary data prior to their analysis, our protocol can be used to increase the reliability of downstream MR analyses. Our pipeline is available to other researchers via the CheckSumStats package (https://github.com/MRCIEU/CheckSumStats).

The role of SOD2 and NOS2 genes in the molecular aspect of bladder cancer pathophysiology

Bladder cancer (BC) is a severe health problem of the genitourinary system and is characterised by a high risk of recurrence. According to the recent GLOBOCAN report, bladder cancer accounts for 3% of diagnosed cancers in the world, taking 10th place on the list of the most common cancers. Despite numerous studies, the full mechanism of BC development remains unknown. Nevertheless, precious results suggest a crucial role of oxidative stress in the development of BC. Therefore, this study explores whether the c. 47 C > T (rs4880)-SOD2, (c. 1823 C > T (rs2297518) and g.-1026 C > A (rs2779249)-NOS2(iNOS) polymorphisms are associated with BC occurrence and whether the bladder carcinogenesis induces changes in SOD2 and NOS2 expression and methylation status in peripheral blood mononuclear cells (PBMCs). In this aim, the TaqMan SNP genotyping assay, TaqMan Gene Expression Assay, and methylation-sensitive high-resolution melting techniques were used to genotype profiling and evaluate the expression of the genes and the methylation status of their promoters, respectively. Our findings confirm that heterozygote of the g.-1026 C > A SNP was associated with a decreased risk of BC. Moreover, we detected that BC development influenced the expression level and methylation status of the promoter region of investigated genes in PBMCs. Concluding, our results confirmed that oxidative stress, especially NOS2 polymorphisms and changes in the expression and methylation of the promoters of SOD2 and NOS2 are involved in the cancer transformation initiation of the cell urinary bladder.

Genome-wide Association Study of Bladder Cancer Reveals New Biological and Translational Insights

BACKGROUND

Genomic regions identified by genome-wide association studies (GWAS) for bladder cancer risk provide new insights into etiology.

OBJECTIVE

To identify new susceptibility variants for bladder cancer in a meta-analysis of new and existing genome-wide genotype data.

DESIGN, SETTING, AND PARTICIPANTS

Data from 32 studies that includes 13,790 bladder cancer cases and 343,502 controls of European ancestry were used for meta-analysis.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSES

Log-additive associations of genetic variants were assessed using logistic regression models. A fixed-effects model was used for meta-analysis of the results. Stratified analyses were conducted to evaluate effect modification by sex and smoking status. A polygenic risk score (PRS) was generated on the basis of known and novel susceptibility variants and tested for interaction with smoking.

RESULTS AND LIMITATIONS

Multiple novel bladder cancer susceptibility loci (6p.22.3, 7q36.3, 8q21.13, 9p21.3, 10q22.1, 19q13.33) as well as improved signals in three known regions (4p16.3, 5p15.33, 11p15.5) were identified, bringing the number of independent markers at genome-wide significance (p < 5 × 10-8) to 24. The 4p16.3 (FGFR3/TACC3) locus was associated with a stronger risk for women than for men (p-interaction = 0.002). Bladder cancer risk was increased by interactions between smoking status and genetic variants at 8p22 (NAT2; multiplicative p value for interaction [pM-I] = 0.004), 8q21.13 (PAG1; pM-I = 0.01), and 9p21.3 (LOC107987026/MTAP/CDKN2A; pM-I = 0.02). The PRS based on the 24 independent GWAS markers (odds ratio per standard deviation increase 1.49, 95% confidence interval 1.44-1.53), which also showed comparable results in two prospective cohorts (UK Biobank, PLCO trial), revealed an approximately fourfold difference in the lifetime risk of bladder cancer according to the PRS (e.g., 1st vs 10th decile) for both smokers and nonsmokers.

CONCLUSIONS

We report novel loci associated with risk of bladder cancer that provide clues to its biological underpinnings. Using 24 independent markers, we constructed a PRS to stratify lifetime risk. The PRS combined with smoking history, and other established risk factors, has the potential to inform future screening efforts for bladder cancer.

PATIENT SUMMARY

We identified new genetic markers that provide biological insights into the genetic causes of bladder cancer. These genetic risk factors combined with lifestyle risk factors, such as smoking, may inform future preventive and screening strategies for bladder cancer.

Role of the human solute carrier family 14 member 1 gene in hypoxia-induced renal cell carcinoma occurrence and its enlightenment to cancer nursing

BACKGROUND

Hypoxia is considered a critical contributor to renal cell carcinoma progression, including invasion and metastasis. However, the potential mechanisms by which it promotes invasion and metastasis have not yet been clarified. The purpose of this study was to investigate the role and mechanism of hypoxia-induced renal cell carcinoma and provide evidence-based medical proof for improvements to postoperative nursing of renal cell carcinoma patients. A total of 64 patients with renal cell carcinoma were divided into the observation group (nursing based on oxygen administration) and the control group (conventional nursing). Renal function indexes, serum inflammatory factors, and tumor markers were evaluated. The human renal cell carcinoma cell line A498 under hypoxia/normoxia was used as an experimental model in vitro and the biological characteristics and mitochondrial function of the cells were assessed.

RESULTS

Nursing based on oxygen administration decreased the value of renal function indexes, serum inflammatory factors, and tumor markers in renal cell carcinoma patients. Hypoxia was found to induce A498 cell invasion, migration, and the release of inflammatory cytokines, while repressing human solute carrier family 14 member 1 gene expression. Elevated levels of solute carrier family 14 member 1 expression induced mitochondrial reactive oxygen species accumulation, diminished the intracellular adenosine triphosphate level, and destroyed both mitochondrial membrane potential integrity and mitochondrial morphology. Overexpression of the solute carrier family 14 member 1 gene could abolish hypoxia-induced invasion, reduce the migration of A498 cells, inhibit the hypoxia-induced release of inflammatory cytokines, and arrest the cell cycle at the G1/S checkpoint.

CONCLUSIONS

These data reveal that nursing based on oxygen administration can improve the clinical efficacy of renal cell carcinoma therapies, being safe and effective. The results elucidate a mechanism wherein the solute carrier family 14 member 1 gene participates in the occurrence and development of hypoxia-induced renal cell carcinoma in a mitochondria-dependent manner.

Intravesical BCG in patients with non-muscle invasive bladder cancer induces trained immunity and decreases respiratory infections

BACKGROUND

BCG is recommended as intravesical immunotherapy to reduce the risk of tumor recurrence in patients with non-muscle invasive bladder cancer (NMIBC). Currently, it is unknown whether intravesical BCG application induces trained immunity.

METHODS

The aim of this research was to determine whether BCG immunotherapy induces trained immunity in NMIBC patients. We conducted a prospective observational cohort study in 17 NMIBC patients scheduled for BCG therapy and measured trained immunity parameters at 9 time points before and during a 1-year BCG maintenance regimen. Ex vivo cytokine production by peripheral blood mononuclear cells, epigenetic modifications, and changes in the monocyte transcriptome were measured. The frequency of respiratory infections was investigated in two larger cohorts of BCG-treated and non-BCG treated NMIBC patients as a surrogate measurement of trained immunity. Gene-based association analysis of genetic variants in candidate trained immunity genes and their association with recurrence-free survival and progression-free survival after BCG therapy was performed to investigate the hypothesized link between trained immunity and clinical response.

RESULTS

We found that intravesical BCG does induce trained immunity based on an increased production of TNF and IL-1β after heterologous ex vivo stimulation of circulating monocytes 6-12 weeks after intravesical BCG treatment; and a 37% decreased risk (OR 0.63 (95% CI 0.40 to 1.01)) for respiratory infections in BCG-treated versus non-BCG-treated NMIBC patients. An epigenomics approach combining chromatin immuno precipitation-sequencing and RNA-sequencing with in vitro trained immunity experiments identified enhanced inflammasome activity in BCG-treated individuals. Finally, germline variation in genes that affect trained immunity was associated with recurrence and progression after BCG therapy in NMIBC.

CONCLUSION

We conclude that BCG immunotherapy induces trained immunity in NMIBC patients and this may account for the protective effects against respiratory infections. The data of our gene-based association analysis suggest that a link between trained immunity and oncological outcome may exist. Future studies should further investigate how trained immunity affects the antitumor immune responses in BCG-treated NMIBC patients.

Implementation of individualised polygenic risk score analysis: a test case of a family of four

BACKGROUND

Polygenic risk scores (PRS) have been widely applied in research studies, showing how population groups can be stratified into risk categories for many common conditions. As healthcare systems consider applying PRS to keep their populations healthy, little work has been carried out demonstrating their implementation at an individual level.

CASE PRESENTATION

We performed a systematic curation of PRS sources from established data repositories, selecting 15 phenotypes, comprising an excess of 37 million SNPs related to cancer, cardiovascular, metabolic and autoimmune diseases. We tested selected phenotypes using whole genome sequencing data for a family of four related individuals. Individual risk scores were given percentile values based upon reference distributions among 1000 Genomes Iberians, Europeans, or all samples. Over 96 billion allele effects were calculated in order to obtain the PRS for each of the individuals analysed here.

CONCLUSIONS

Our results highlight the need for further standardisation in the way PRS are developed and shared, the importance of individual risk assessment rather than the assumption of inherited averages, and the challenges currently posed when translating PRS into risk metrics.

Mechanism of Sex Differences in Bladder Cancer: Evident and Elusive Sex-biasing Factors

Bladder cancer incidence is drastically higher in males than females across geographical, racial, and socioeconomic strata. Despite potential differences in tumor biology, however, male and female bladder cancer patients are still clinically managed in highly similar ways. While sex hormones and sex chromosomes have been shown to promote observed sex differences, a more complex story lies beneath these evident sex-biasing factors than previously appreciated. Advances in genomic technology have spurred numerous preclinical studies characterizing elusive sex-biasing factors such as epigenetics, X chromosome inactivation escape genes, single nucleotide polymorphism, transcription regulation, metabolism, immunity, and many more. Sex-biasing effects, if properly understood, can be leveraged by future efforts in precision medicine based on a patient's biological sex. In this review, we will highlight key findings from the last half century that demystify the intricate ways in which sex-specific biology contribute to differences in pathogenesis as well as discuss future research directions.

SLC35E2 promoter mutation as a prognostic marker of esophageal squamous cell carcinoma

AIMS

Esophageal squamous cell carcinoma (ESCC) is one of the deadliest digestive tract cancer with poor prognosis. In our previous comprehensive genomics study, we identified that hotspot mutations in the solute carrier family 35 member E2 (SLC35E2) promoter region was significantly associated with worse prognosis in patients with ESCC. However, the biological function and molecular mechanism of SLC35E2 remains unclear. This study was to investigate the malignant function and mechanism of SLC35E2 in ESCC.

MAIN METHODS

Western blotting and qRT-PCR were used to assess the expression of SLC35E2 in ESCC cell lines. Luciferase assay and chromatin immunoprecipitation (ChIP) assay were used to assess the transcriptional inhibition of KLF4. Incucyte cell proliferation assay, colony formation assay and subcutaneous tumor formation in nude mice were used to assess the malignant function of SLC35E2.

KEY FINDINGS

SLC35E2 can promote ESCC cell proliferation in vitro and in vivo. Krüppel-like factor 4 (KLF4), a transcriptional repressor in ESCC, binds to the SLC35E2 promoter and represses the expression of SLC35E2. The transcriptional suppression of KLF4 can be blocked by the mutation at -118 site of the SLC35E2 promoter. Besides, the accumulation of SLC35E2 expression contributes to the malignant phenotype of ESCC.

SIGNIFICANCE

These results indicate that SLC35E2 may be used as a biomarker for prognosis as well as a therapeutic target for patients with ESCC.

Genetic variants in choline metabolism pathway are associated with the risk of bladder cancer in the Chinese population

Choline metabolism alteration is considered as a metabolic hallmark in cancer, reflecting the complex interactions between carcinogenic signaling pathways and cancer metabolism, but little is known about whether genetic variants in the metabolism pathway contribute to the susceptibility of bladder cancer. Herein, a case-control study comprising 580 patients and 1,101 controls was carried out to analyze the association of bladder cancer with genetic variants on candidate genes involved in the choline metabolism pathway using unconditional logistic regression. Gene expression data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database were applied for differential gene expression analysis. Cox regression was also applied to estimate the role of candidate genes on bladder cancer prognosis. Our results demonstrated that C allele of rs6810830 in ENPP6 was a significant protective allele of bladder cancer, compared to the T allele [Odds ratio (OR) = 0.74, 95% confidence interval (CI) = 0.64-0.86, P = 7.14 × 10^-5 in additive model]. Besides, we also found that the expression of ENPP6 remarkably decreased in bladder tumors compared with normal tissues. Moreover, high expression of ENPP6 was associated with worse overall survival (OS) in bladder cancer patients [hazard ratio (HR) with their 95% CI 1.39 (1.02-1.90), P = 0.039]. In conclusion, our results suggested that SNP rs6810830 (T > C) in ENPP6 might be a potential susceptibility loci for bladder cancer, and these findings provided novel insights into the underlying mechanism of choline metabolism in cancers.

Genome-Wide Association Study Adjusted for Occupational and Environmental Factors for Bladder Cancer Susceptibility

This study examined the effects of single-nucleotide polymorphisms (SNPs) on the development of bladder cancer, adding longest-held occupational and industrial history as regulators. The genome purified from blood was genotyped, followed by SNP imputation. In the genome-wide association study (GWAS), several patterns of industrial/occupational classifications were added to logistic regression models. The association test between bladder cancer development and the calculated genetic score for each gene region was evaluated (gene-wise analysis). In the GWAS and gene-wise analysis, the gliomedin gene satisfied both suggestive association levels of 10⁻⁵ in the GWAS and 10⁻⁴ in the gene-wise analysis for male bladder cancer. The expression of the gliomedin protein in the nucleus of bladder cancer cells decreased in cancers with a tendency to infiltrate and those with strong cell atypia. It is hypothesized that gliomedin is involved in the development of bladder cancer.

Identifying a hypoxia related score to predict the prognosis of bladder cancer: a study with The Cancer Genome Atlas (TCGA) database

Background

Recurrence is common in bladder cancer, with a hypoxic tumor microenvironment (TME) playing a role in genetic instability and prognosis of bladder cancer. However, we still lack practical hypoxia related model for predicting the prognosis of bladder cancer. In this study, we identified new prognosis-related hypoxia genes and established a new hypoxia score related signature.

Methods

The Gene Set Variation Analysis (GSVA) algorithm was utilized to calculate the hypoxia score of bladder cancer cases found on the The Cancer Genome Atlas (TCGA) database on the gene expression profiles. The cases were first divided into low- and high-hypoxia score groups and then differentially expressed genes (DEGs) expression analysis was conducted. Hypoxia-related genes were identified using weighted gene co-expression network analysis (WGCNA). We then conducted a protein-protein interaction (PPI) network and carried out functional enrichment analysis of the genes that overlapped between DEGs and hypoxia-related genes. LASSO Cox regression analysis was used to establish a hypoxia-related prognostic signature, which was validated using the GSE69795 dataset downloaded from GEO database.

Results

Results from Kaplan-Meier analysis showed that patients with a high hypoxia score had significantly poor overall survival compared to patients with low hypoxia score. We selected 270 DEGs between low- and high-hypoxia score groups, while WGCNA analysis identified 1,313 genes as hypoxia-related genes. A total of 170 genes overlapped between DEGs and hypoxia-related genes. LASSO algorithms identified 29 genes associated with bladder cancer prognosis, which were used to construct a novel 29-gene signature model. The prognostic risk model performed well, since the receiver operating characteristic (ROC) curve showed an accuracy of 0.802 (95% CI: 0.759–0.844), and Cox proportional hazards regression analysis proved the model an independent predictor with hazard ratio (HR) =1.789 (95% CI: 1.585–2.019) (P<0.001). The low-risk score patients had remarkably longer overall survival than patients with a higher score (survival rate 71.06% vs. 23.66%) in the The Cancer Genome Atlas (TCGA) cohort (P<0.0001) and in the dataset GSE69795 (P=0.0079).

Conclusions

We established a novel 29-gene hypoxia-related signature model to predict the prognosis of bladder cancer cases. This model and identified hypoxia-related genes may further been used as biomarkers, assisting the evaluation of prognosis of bladder cancer cases and decision making in clinical practice.

Racial differences in the risk of second primary bladder cancer following radiation therapy among localized prostate cancer patients

OBJECTIVES

To investigate the race-specific second primary bladder cancer (SPBC) risk following prostatic irradiation.

METHODS

Louisiana residents who were diagnosed with localized prostate cancer (PCa) in 1996-2013 and received surgery or radiation were included. Patients were followed until SPBC diagnosis, death, or Dec. 2018. The exposure variable was type of treatment (radiation only vs. surgery only). The outcome was time from PCa diagnosis to SPBC diagnosis, stratified by race. Fine and Gray's competing risk model was applied with death as a competing event and adjustment of sociodemographic and tumor characteristics. We used 5 years and 10 years as lag time in the analyses.

RESULTS

A total of 26,277 PCa patients with a median follow-up of 10.7 years were analyzed, including 18,598 white and 7679 black patients. About 42.9 % of whites and 45.7 % of blacks received radiation. SPBC counted for 1.84 % in the radiation group and 0.90 % in the surgery group among white patients and for 0.91 % and 0.58 %, respectively, among black patients. The adjusted subdistribution hazard ratio of SPBC was 1.80 (95 % CI: 1.30-2.48) for radiation recipients compared to surgery recipients among white patients; 1.93 (95 % CI: 1.36-2.74) if restricted to external beam radiation therapy (EBRT). The SPBC risk was not significantly different between irradiated and surgically treated among blacks.

CONCLUSIONS

The SPBC risk is almost two-fold among white irradiated PCa patients compared to their counterparts treated surgically. Our findings highlight the need for enhanced surveillance for white PCa survivors receiving radiotherapy, especially those received EBRT.

A guide to plasma membrane solute carrier proteins

This review aims to serve as an introduction to the solute carrier proteins (SLC) superfamily of transporter proteins and their roles in human cells. The SLC superfamily currently includes 458 transport proteins in 65 families that carry a wide variety of substances across cellular membranes. While members of this superfamily are found throughout cellular organelles, this review focuses on transporters expressed at the plasma membrane. At the cell surface, SLC proteins may be viewed as gatekeepers of the cellular milieu, dynamically responding to different metabolic states. With altered metabolism being one of the hallmarks of cancer, we also briefly review the roles that surface SLC proteins play in the development and progression of cancer through their influence on regulating metabolism and environmental conditions.

The Interplay between Oxidative Stress, Inflammation and Angiogenesis in Bladder Cancer Development

In 2018, 550,000 people were diagnosed with bladder cancer (BC), of which nearly 200,000 people died. Moreover, men are 4 times more likely than women to be diagnosed with BC. The risk factors include exposure to environmental and occupational chemicals, especially tobacco smoke, benzidine and genetic factors. Despite numerous studies, the molecular basis of BC development remains unclear. A growing body of evidence suggests that inflammation, oxidant-antioxidant imbalance and angiogenesis disorders may play a significant role in the development and progression of bladder cancer. The patients with bladder cancer were characterised by an increased level of reactive oxygen species (ROS), the products of lipid peroxidation, proinflammatory cytokines and proangiogenic factors as compared to controls. Furthermore, it was shown that polymorphisms localised in genes associated with these pathways may modulate the risk of BC. Interestingly, ROS overproduction may induce the production of proinflammatory cytokines, which finally activated angiogenesis. Moreover, the available literature shows that both inflammation and oxidative stress may lead to activation of angiogenesis and tumour progression in BC patients.

Whole Genome Interpretation for a Family of Five

Although best practices have emerged on how to analyse and interpret personal genomes, the utility of whole genome screening remains underdeveloped. A large amount of information can be gathered from various types of analyses via whole genome sequencing including pathogenicity screening, genetic risk scoring, fitness, nutrition, and pharmacogenomic analysis. We recognize different levels of confidence when assessing the validity of genetic markers and apply rigorous standards for evaluation of phenotype associations. We illustrate the application of this approach on a family of five. By applying analyses of whole genomes from different methodological perspectives, we are able to build a more comprehensive picture to assist decision making in preventative healthcare and well-being management. Our interpretation and reporting outputs provide input for a clinician to develop a healthcare plan for the individual, based on genetic and other healthcare data.

Sickle Cell Anemia: Variants in the CYP2D6, CAT, and SLC14A1 Genes Are Associated With Improved Hydroxyurea Response

Differences in hydroxyurea response in sickle cell anemia may arise due to a series of factors with genetic factors appearing to be predominant. This study aims to investigate the effects of single nucleotide polymorphisms in genes encoding drug-metabolizing enzymes and solute carriers on hydroxyurea response, in patients with sickle cell anemia. For that purpose, a total number of 90 patients with sickle cell anemia were recruited, 45 were undergoing hydroxyurea treatment, while 45 were not under the treatment. Association analyses were performed between CYP3A4 (rs2740574), CYP2D6 (rs3892097), CAT (rs7943316 and rs1001179), and SLC14A1 (rs2298720) variants and laboratory parameters. According to our findings, patients with hydroxyurea treatment demonstrated higher HbF levels and a significant improvement in hemolytic, hepatic, inflammatory, and lipid parameters in comparison to those without the treatment. We also found significant associations between the CYP2D6 (rs3892097), CAT (rs7943316 and rs1001179), and SLC14A1 (rs2298720) variants and an improvement of the therapeutic effects, specifically the hemolytic, hepatic, inflammatory, lipid, and renal parameters. In conclusion, our results highlight the importance of the investigated variants, and their strong association with hydroxyurea efficacy in patients with sickle cell anemia, which may be considered in the future as genetic markers.

SLC14A1 (UT-B) gene rearrangement in urothelial carcinoma of the bladder: a case report

BACKGROUND

Bladder cancer (BC) is a common and deadly disease. Over the past decade, a number of genetic alterations have been reported in BC. Bladder urothelium expresses abundant urea transporter UT-B encoded by Slc14a1 gene at 18q12.3 locus, which plays an important role in preventing high concentrated urea-caused cell injury. Early genome-wide association studies (GWAS) showed that UT-B gene mutations are genetically linked to the urothelial bladder carcinoma (UBC). In this study, we examined whether Slc14a1 gene has been changed in UBC, which has never been reported.

CASE PRESENTATION

A 59-year-old male was admitted to a hospital with the complaint of gross hematuria for 6 days. Ultrasonography revealed a size of 2.8 × 1.7 cm mass lesion located on the rear wall and dome of the bladder. In cystoscopic examination, papillary tumoral lesions 3.0-cm in total diameter were seen on the left wall of the bladder and 2 cm to the left ureteric orifice. Transurethral resection of bladder tumor (TURBT) was performed. Histology showed high-grade non-muscle invasive UBC. Immunostaining was negative for Syn, CK7, CK20, Villin, and positive for HER2, BRCA1, GATA3. Using a fluorescence in situ hybridization (FISH), Slc14a1 gene rearrangement was identified by a pair of break-apart DNA probes.

CONCLUSIONS

We for the first time report a patient diagnosed with urothelial carcinoma accompanied with split Slc14a1 gene abnormality, a crucial gene in bladder.

No clear associations of adult BMI and diabetes mellitus with non-muscle invasive bladder cancer recurrence and progression

Background

Non-muscle invasive bladder cancer patients are at high risk for tumour recurrence and progression, hence an intensive follow-up procedure is recommended which is costly. Identification of factors that are associated with the risk of recurrence and progression may enable personalized follow-up schedules. Obesity and diabetes mellitus may be associated with a worse prognosis, but the evidence is limited and inconsistent. Our objective was to determine the associations of BMI and diabetes mellitus with risks of recurrence and progression among non-muscle invasive bladder cancer patients.

Methods

A population-based cohort of patients diagnosed with non-muscle invasive bladder cancer between 1995 and 2010 was retrospectively identified from the Netherlands Cancer Registry and invited to participate in the Nijmegen Bladder Cancer Study (n = 1,433). Average weight during adult life, height, and diabetes mellitus diagnosis were self-reported by use of a questionnaire. Clinical follow-up data were retrieved from medical files. Associations were quantified using proportional hazard analyses. For all analyses, minimal adjustment sets were selected using a Directed Acyclic Graph.

Results

Fourteen percent of the patients indicated to be diagnosed with diabetes mellitus, and more than half was overweight (45%) or obese (9%). Compared to healthy weight, overweight and obesity were not associated with risk of recurrence (adjusted hazard ratio (HR) = 1.02; 95% confidence interval (CI): 0.86–1.22, and HR = 1.02; 95% CI: 0.76–1.38, respectively) and overall progression (HR = 1.04; 95% CI: 0.74–1.44, and HR = 1.20; 95% CI: 0.69–2.09, respectively). Also, no clear associations of diabetes mellitus with risk of recurrence (HR = 1.22; 95% CI: 0.98–1.54) and overall progression (HR = 1.16; 95% CI: 0.76–1.76) were found.

Conclusion

Average BMI during adult life and diabetes mellitus were not clearly associated with risk of recurrence or progression in non-muscle invasive bladder cancer. Prospective cohort studies with detailed information on BMI and diabetes mellitus before and after diagnosis are needed to confirm these findings.

HDMAC: A Web-Based Interactive Program for High-Dimensional Analysis of Molecular Alterations in Cancer

Recent advances in high-throughput genomic technologies have nurtured a growing demand for statistical tools to facilitate identification of molecular changes as potential prognostic biomarkers or drugable targets for personalized precision medicine. In this study, we developed a web-based interactive and user-friendly platform for high-dimensional analysis of molecular alterations in cancer (HDMAC) (https://ripsung26.shinyapps.io/rshiny/). On HDMAC, several penalized regression models that are suitable for high-dimensional data analysis, Ridge, Lasso and adaptive Lasso, are offered, with Cox regression for survival and logistic regression for binary outcomes. Choice of a first-step screening is provided to address the multiple-comparison issue that often arises with large-volume genomic data. Hazard ratio or estimated coefficient is provided with each selected gene so that a multivariate regression model may be built based on the genes selected. Cross validation is provided as the method to estimate the prediction power of each regression model. In addition, R codes are also provided to facilitate download of whole sets of molecular variables from TCGA. In this study, illustration of the use of HDMAC was made through a set of data on gene mutations and a set on mRNA expression from ovarian cancer patients and a set on mRNA expression from bladder cancer patient. From the analysis of each set of data, a list of candidate genes was obtained that might be associated with mutations or abnormal expression of genes in ovarian and bladder cancers. HDMAC offers a solution for rigorous and validation analysis of high-dimensional genomic data.

The Rare Variant rs35356162 in UHRF1BP1 Increases Bladder Cancer Risk in Han Chinese Population

Background: Seventeen loci have been found to be associated with bladder cancer risk by genome-wide association studies (GWAS) in European population. However, little is known about contribution of low-frequency and rare variants to bladder cancer susceptibility, especially in Eastern population.

Methods: We performed a three-stage case-control study including 3,399 bladder cancer patients and 4,647 controls to identify low-frequency and rare variants associated with bladder cancer risk in Han Chinese. We examined exome-array data in 1,019 bladder cancer patients and 1,008 controls in discovery stage. Two replication stages were included to validate variants identified. Bonferroni adjustment was performed to define statistical significance. Logistic regression was conducted to evaluate single marker association with bladder cancer risk. We used SKAT-O method to perform gene level-based analysis. We also conduct additional experiments to explore the underlying mechanism of filtered gene(s).

Results: We identified a novel rare coding variant (rs35356162 in UHRF1BP1: G > T, OR = 4.332, P = 3.62E-07 < 7.93E-07, Bonferroni cutoff) that increased bladder cancer risk in Han Chinese. Gene-level analysis showed a significant association of UHRF1BP1 (P = 4.47E-03) with bladder cancer risk. Experiments indicated down-regulation of UHRF1BP1 promoted migration and invasion through epithelial-mesenchymal transition in bladder cancer cell lines.

Conclusion: The rare variant of UHRF1BP1, rs35356162, increases bladder cancer risk in Han Chinese and UHRF1BP1 might act as a tumor suppressor in bladder cancer development and progression.

Summary: Little is known about potential contribution of low-frequency and rare variants to bladder cancer susceptibility. We performed a three-stage case-control study and identified a new rare variant, rs35356162 in UHRF1BP1, which increased bladder cancer risk in Han Chinese.

Identification of the key genes and microRNAs in adult acute myeloid leukemia with FLT3 mutation by bioinformatics analysis

Background: Associated with poor prognosis, FMS-like tyrosine kinase 3 (FLT3) mutation appeared frequently in acute myeloid leukemia (AML). Herein, we aimed to identify the key genes and miRNAs involved in adult AML with FLT3 mutation and find possible therapeutic targets for improving treatment. Materials: Gene and miRNA expression data and survival profiles were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database. EdgeR of R platform was applied to identify the differentially expressed genes and miRNAs (DEGs, DE-miRNAs). Gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed by Metascape and DAVID. And protein-protein interaction network, miRNA-mRNA regulatory network and clustering modules analyses were performed by STRING database and Cytoscape software. Results: Survival analysis showed FLT3 mutation led to adverse outcome in AML. 24 DE-miRNAs (6 upregulated, 18 downregulated) and 250 DEGs (54 upregulated, 196 downregulated) were identified. Five miRNAs had prognostic value and the results matched their expression levels (miR-1-3p, miR-10a-3p, miR-10a-5p, miR-133a-3p and miR-99b-5p). GO analysis showed DEGs were enriched in skeletal system development, blood vessel development, cartilage development, tissue morphogenesis, cartilage morphogenesis, cell morphogenesis involved in differentiation, response to growth factor, cell-substrate adhesion and so on. The KEGG analysis showed DEGs were enriched in PI3K-Akt signaling pathway, ECM-receptor interaction and focal adhesion. Seven genes (LAMC1, COL3A1, APOB, COL1A2, APP, SPP1 and FSTL1) were simultaneously identified by hub gene analysis and module analysis. SLC14A1, ARHGAP5 and PIK3CA, the target genes of miR-10a-3p, resulted in poor prognosis. Conclusion: Our study successfully identified molecular markers, processes and pathways affected by FLT3 mutation in AML. Furthermore, miR-10a-3p, a novel oncogene, might involve in the development of FLT3 mutation adult AML by targeting SLC14A1, ARHGAP5 and PIK3CA.

Osmotic regulation of UT-B urea transporters in the RT4 human urothelial cell line

Facilitative UT-B urea transporters play important physiological roles in numerous tissues, including the urino-genital tract. Previous studies have shown that urothelial UT-B transporters are crucial to bladder function in a variety of mammalian species. Using the RT4 bladder urothelial cell line, this study investigated the potential osmotic regulation of human UT-B transporters. Initial end-point PCR experiments confirmed expression of both UT-B1 and UT-B2 transcripts in RT4 cells. Western blotting analysis revealed glycosylated UT-B protein to be highly abundant and immunolocalization experiments showed it was predominantly located on the plasma membrane. Further PCR experiments suggested that a 48 hr, NaCl-induced raise in external osmolality increased expression of UT-B transcripts. Importantly, these NaCl-induced changes also significantly increased UT-B protein abundance (p < .01, n = 7, ANOVA), whereas mannitol-induced changes in external osmolality had no effect (NS, n = 4, ANOVA). Finally, similar increases in both UT-B RNA expression and protein abundance were observed with urea-induced changes to external osmolality (p < .05, n = 4, ANOVA). In conclusion, these findings strongly suggest that increases in external osmolality, via either NaCl or urea, can regulate human urothelial UT-B transporters.

Integrated analysis of quantitative proteome and transcriptional profiles reveals abnormal gene expression and signal pathway in bladder cancer

BACKGROUND

Bladder cancer (BCa) is a tumor associated with high morbidity and mortality and its incidence is increasing worldwide. However, the pathogenesis of bladder cancer is not well understood.

OBJECTIVE

To further illustrate the molecular mechanisms involved in the pathogenesis of BCa and identify potential therapeutic targets, we combined the transcriptomic analysis with RNA sequencing and tandem mass tags (TMT)-based proteomic methods to quantitatively screen the differentially expressed genes and proteins between bladder cancer tissues (BC) and adjacent normal tissues (AN).

RESULTS

Transcriptome and proteome studies indicated 7094 differentially expressed genes (DEGs) and 596 differentially expressed proteins (DEPs) between BC and AN, respectively. GO enrichment analyses revealed that cell adhesion, calcium ion transport, and regulation of ATPase activity were highly enriched in BCa. Moreover, several key signaling pathway were identified as of relevance to BCa, in particular the ECM-receptor interaction, cell adhesion molecules (CAMs), and PPAR signaling pathway. Interestingly, 367 genes were shared by DEGs and DEPs, and a significant positive correlation between mRNA and translation profiles was found.

CONCLUSION

In summary, this joint analysis of transcript and protein profiles provides a comprehensive reference map of gene activity regarding the disease status of BCa.

Systematic evaluation of cancer-specific genetic risk score for 11 types of cancer in The Cancer Genome Atlas and Electronic Medical Records and Genomics cohorts

BACKGROUND

Genetic risk score (GRS) is an odds ratio (OR)-weighted and population-standardized method for measuring cumulative effect of multiple risk-associated single nucleotide polymorphisms (SNPs). We hypothesize that GRS is a valid tool for risk assessment of most common cancers.

METHODS

Utilizing genotype and phenotype data from The Cancer Genome Atlas (TCGA) and Electronic Medical Records and Genomics (eMERGE), we tested 11 cancer-specific GRSs (bladder, breast, colorectal, glioma, lung, melanoma, ovarian, pancreatic, prostate, renal, and thyroid cancer) for association with the respective cancer type. Cancer-specific GRSs were calculated, for the first time in these cohorts, based on previously published risk-associated SNPs using the Caucasian subjects in these two cohorts.

RESULTS

Mean cancer-specific GRS in the population controls of eMERGE approximated the expected value of 1.00 (between 0.98 and 1.02) for all 11 types of cancer. Mean cancer-specific GRS was consistently higher in respective cancer patients than controls for all 11 types of cancer (P < 0.05). When subjects were categorized into low-, average-, and high-risk groups based on cancer-specific GRS (<0.5, 0.5-1.5, and >1.5, respectively), significant dose-response associations of higher cancer-specific GRS with higher OR of respective type of cancer were found for nine types of cancer (P_-trend  < 0.05). More than 64% subjects in the population controls of eMERGE can be classified as high risk for at least one type of these cancers.

CONCLUSION

Validity of GRS for predicting cancer risk is demonstrated for most types of cancer. If confirmed in larger studies, cancer-specific GRS may have the potential for developing personalized cancer screening strategy.

Revisiting Histone Deacetylases in Human Tumorigenesis: The Paradigm of Urothelial Bladder Cancer

Urinary bladder cancer is a common malignancy, being characterized by substantial patient mortality and management cost. Its high somatic-mutation frequency and molecular heterogeneity usually renders tumors refractory to the applied regimens. Hitherto, methotrexate-vinblastine-adriamycin-cisplatin and gemcitabine-cisplatin represent the backbone of systemic chemotherapy. However, despite the initial chemosensitivity, the majority of treated patients will eventually develop chemoresistance, which severely reduces their survival expectancy. Since chromatin regulation genes are more frequently mutated in muscle-invasive bladder cancer, as compared to other epithelial tumors, targeted therapies against chromatin aberrations in chemoresistant clones may prove beneficial for the disease. “Acetyl-chromatin” homeostasis is regulated by the opposing functions of histone acetyltransferases (HATs) and histone deacetylases (HDACs). The HDAC/SIRT (super-)family contains 18 members, which are divided in five classes, with each family member being differentially expressed in normal urinary bladder tissues. Since a strong association between irregular HDAC expression/activity and tumorigenesis has been previously demonstrated, we herein attempt to review the accumulated published evidences that implicate HDACs/SIRTs as critical regulators in urothelial bladder cancer. Moreover, the most extensively investigated HDAC inhibitors (HDACis) are also analyzed, and the respective clinical trials are also described. Interestingly, it seems that HDACis should be preferably used in drug-combination therapeutic schemes, including radiation.

Epidemiology, prevention, screening, diagnosis, and evaluation: update of the ICUD-SIU joint consultation on bladder cancer

PURPOSE

To update current recommendations on prevention, screening, diagnosis, and evaluation of bladder cancer (BC) based on a thorough assessment of the most recent literature on these topics.

METHODS

A non-systematic review was performed, including articles until June 2017. A variety of original articles, reviews, and editorials were selected according to their epidemiologic, demographic, and clinical relevance. Assessment of the level of evidence and grade of recommendations was performed according to the International Consultation on Urological Diseases grading system.

RESULTS

BC is the ninth most common cancer worldwide with 430,000 new cases in 2012. Currently, approximately 165,000 people die from the disease annually. Absolute incidence and prevalence of BC are expected to rise significantly during the next decades because of population ageing. Tobacco smoking is still the main risk factor, accounting for about 50% of cases. Smoking cessation is, therefore, the most relevant recommendation in terms of prevention, as the risk of developing BC drops almost 40% within 5 years of cessation. BC screening is not recommended for the general population. BC diagnosis remains mainly based on cystoscopy, but development of new endoscopic and imaging technologies may rapidly change the diagnosis algorithm. The same applies for local, regional, and distant staging modalities.

CONCLUSIONS

A thorough understanding of epidemiology, risk factors, early detection strategies, diagnosis, and evaluation is essential for correct, evidence-based management of BC patients. Recent developments in endoscopic techniques and imaging raise the hope for providing better risk-adopted approaches and thereby improving clinical outcomes.

Investigation of facilitative urea transporters in the human gastrointestinal tract

The symbiotic relationship between humans and their intestinal microbiome is supported by urea nitrogen salvaging. Previous studies have shown that colonic UT-B urea transporters play a significant role in this important physiological process. This current study investigated UT-A and UT-B urea transporter expression along the human gastrointestinal tract. Initial end-point PCR experiments determined that UT-A RNA was predominantly expressed in the small intestine, while UT-B RNA was expressed in stomach, small intestine, and colon. Using western blotting experiments, a strong 40-60 kDa UT-B signal was found to be abundant in both ileum and colon. Importantly, this signal was deglycosylated by PNGaseF enzyme treatment to a core protein of 30 kDa in both tissues. Further immunolocalization studies revealed UT-B transporter proteins were present at the apical membrane of the villi in the ileum, but predominantly at the basolateral membrane of the colonic surface epithelial cells. Finally, a blind scoring immunolocalization study suggested that there was no significant difference in UT-B abundance throughout the colon (NS, ANOVA, N = 5-21). In conclusion, this current study suggested UT-B to be the main human intestinal urea transporter. Intriguingly, these data suggested that the same UT-B isoform was present in all intestinal epithelial cells, but that the precise cellular location varied.

Identification of an enhancer region within the TP63/LEPREL1 locus containing genetic variants associated with bladder cancer risk

Purpose

Genome-wide association studies (GWAS) have led to the identification of a bladder cancer susceptibility variant (rs710521) in a non-coding intergenic region between the TP63 and LEPREL1 genes on chromosome 3q28, suggesting a role in the transcriptional regulation of these genes. In this study, we aimed to functionally characterize the 3q28 bladder cancer risk locus.

Methods

Fine-mapping was performed by focusing on the region surrounding rs710521, and variants were prioritized for further experiments using ENCODE regulatory data. The enhancer activity of the identified region was evaluated using dual-luciferase assays. CRISPR/Cas9-mediated deletion of the enhancer region was performed and the effect of this deletion on cell proliferation and gene expression levels was evaluated using CellTiter-Glo and RT-qPCR, respectively.

Results

Fine-mapping of the GWAS signal region led to the identification of twenty SNPs that showed a stronger association with bladder cancer risk than rs710521. Using publicly available data on regulatory elements and sequences, an enhancer region containing the bladder cancer risk variants was identified. Through reporter assays, we found that the presence of the enhancer region significantly increased ΔNTP63 promoter activity in bladder cancer-derived cell lines. CRISPR/Cas9-mediated deletion of the enhancer region reduced the viability of bladder cancer cells by decreasing the expression of ΔNTP63 and p63 target genes.

Conclusions

Taken together, our data show that bladder cancer risk-associated variants on chromosome 3q28 are located in an active enhancer region. Further characterization of the allele-specific activity of the identified enhancer and its target genes may lead to the identification of novel signaling pathways involved in bladder carcinogenesis.

Electronic supplementary material

The online version of this article (10.1007/s13402-018-0393-5) contains supplementary material, which is available to authorized users.

A Decade of GWAS Results in Lung Cancer

Genome-wide association studies (GWAS) were successful to identify genetic factors robustly associated with lung cancer. This review aims to synthesize the literature in this field and accelerate the translation of GWAS discoveries into results that are closer to clinical applications. A chronologic presentation of published GWAS on lung cancer susceptibility, survival, and response to treatment is presented. The most important results are tabulated to provide a concise overview in one read. GWAS have reported 45 lung cancer susceptibility loci with varying strength of evidence and highlighted suspected causal genes at each locus. Some genetic risk loci have been refined to more homogeneous subgroups of lung cancer patients in terms of histologic subtypes, smoking status, gender, and ethnicity. Overall, these discoveries are an important step for future development of new therapeutic targets and biomarkers to personalize and improve the quality of care for patients. GWAS results are on the edge of offering new tools for targeted screening in high-risk individuals, but more research is needed if GWAS are to pay off the investment. Complementary genomic datasets and functional studies are needed to refine the underlying molecular mechanisms of lung cancer preliminarily revealed by GWAS and reach results that are medically actionable. Cancer Epidemiol Biomarkers Prev; 27(4); 363-79. ©2018 AACRSee all articles in this CEBP Focus section, "Genome-Wide Association Studies in Cancer."

Identification and replication of the interplay of four genetic high-risk variants for urinary bladder cancer

Little is known whether genetic variants identified in genome-wide association studies interact to increase bladder cancer risk. Recently, we identified two- and three-variant combinations associated with a particular increase of bladder cancer risk in a urinary bladder cancer case-control series (Leibniz Research Centre for Working Environment and Human Factors at TU Dortmund (IfADo), 1501 cases, 1565 controls). In an independent case-control series (Nijmegen Bladder Cancer Study, NBCS, 1468 cases, 1720 controls) we confirmed these two- and three-variant combinations. Pooled analysis of the two studies as discovery group (IfADo-NBCS) resulted in sufficient statistical power to test up to four-variant combinations by a logistic regression approach. The New England and Spanish Bladder Cancer Studies (2080 cases and 2167 controls) were used as a replication series. Twelve previously identified risk variants were considered. The strongest four-variant combination was obtained in never smokers. The combination of rs1014971[AA] near apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like 3A (APOBEC3A) and chromobox homolog 6 (CBX6), solute carrier family 1s4 (urea transporter), member 1 (Kidd blood group) (SLC14A1) exon single nucleotide polymorphism (SNP) rs1058396[AG, GG], UDP glucuronosyltransferase 1 family, polypeptide A complex locus (UGT1A) intron SNP rs11892031[AA] and rs8102137[CC, CT] near cyclin E1 (CCNE1) resulted in an unadjusted odds ratio (OR) of 2.59 (95% CI = 1.93-3.47; P = 1.87 × 10-10), while the individual variant ORs ranged only between 1.11 and 1.30. The combination replicated in the New England and Spanish Bladder Cancer Studies (ORunadjusted = 1.60, 95% CI = 1.10-2.33; P = 0.013). The four-variant combination is relatively frequent, with 25% in never smoking cases and 11% in never smoking controls (total study group: 19% cases, 14% controls). In conclusion, we show that four high-risk variants can statistically interact to confer increased bladder cancer risk particularly in never smokers.

SLC14A1: a novel target for human urothelial cancer

Urinary bladder cancer is the second commonly diagnosed genitourinary malignancy. Previously, bio-molecular alterations have been observed within certain locations such as chromosome 9, retinoblastoma gene and fibroblast growth factor receptor-3. Solute carrier family 14 member 1 (SLC14A1) gene encodes the type-B urea transporter (UT-B) which facilitates the passive movement of urea across cell membrane, and has recently been related with human malignancies, especially for bladder cancer. Herein, we discussed the SLC14A1 gene and UT-B protein properties, aiming to elucidate the expression behavior of SLC14A1 in human bladder cancer. Furthermore, by reviewing some well-established theories regarding the carcinogenesis of bladder cancer, including several genome wide association researches, we have bridged the mechanisms of cancer development with the aberrant expression of SLC14A1. In conclusion, the altered expression of SLC14A1 gene in human urothelial cancer may implicate its significance as a novel target for research.

Lack of association between Kidd blood group system and chronic kidney disease

BACKGROUND

The Kidd blood group system has three antigens, Jka, Jkb and Jk3, found on red blood cells and on endothelial cells of the inner lining of blood vessels in the renal medulla. These are known as urea transporter B (UT-B). Researchers have found that individuals carrying the Jk(a-b-) or Jk-null (UT-B null) phenotypes have a lower urine-concentrating capability and risk of severe renal impairment. This study evaluated the distribution of the Kidd phenotypes in patients with chronic kidney disease and a possible association of Kidd antigens with the development of renal disease.

METHODS

Jka and Jkb antigens were phenotyped using the gel column agglutination test (ID-cards Bio-RAD) in 197 patients with chronic kidney disease and 444 blood donors, as the control group. The phenotype and antigen frequencies between patients and controls were evaluated using the Chi-square method with Yates correction and logistic regression after adjustments for gender and age.

RESULTS

No differences were observed between the Kidd phenotypes frequency distribution between patients with chronic kidney disease and blood donors [Jk(a-b+)=22.3% and 27.2%; Jk(a+b-)=30.5% and 24.3%; Jk(a+b+)=47.25% and 48.4%, respectively].

CONCLUSION

The distribution of Kidd phenotypes found in the studied population is expected for Caucasians; Jka and Jkb antigens and phenotypes were not found to be related to susceptibility for chronic kidney disease.

Polymorphisms of xenobiotic metabolizing enzymes in bladder cancer patients of the Semmelweis University Budapest, Hungary

Polymorphic xenobiotic metabolizing enzymes such as N-acetyltransferase 2 (NAT2) or glutathione S-transferase M1 (GSTM1) are known to modulate bladder cancer risk. As no apparent data were available from Hungary, a former member of the eastern European economic organization, a study was performed in Budapest. In total, 182 bladder cancer cases and 78 cancer-free controls were investigated by questionnaire. Genotypes of NAT2, GSTM1, GSTT1, rs1058396 and rs17674580 were determined by standard methods. Current smokers' crude odds ratio (OR) (3.43) and former smokers crude OR (2.36) displayed a significantly increased bladder cancer risk. The risk rose by a factor of 1.56 per 10 pack years. Exposure to fumes was associated with an elevated bladder cancer risk (23% cases, 13% controls). Sixty-four % of the cases and 59% of controls were slow NAT2 acetylators. It was not possible to establish a particular impact of NAT2*6A and *7B genotypes (15 cases, 8%, 5 controls, 7%). GSTT1 exerted no marked influence on bladder cancer (negative 21% cases vs. 22% controls). The portion of GSTM1 negative bladder cancer patients was increased (63% cases vs. 54% controls). The SLC14A1 SNPs rs1058396[AG/GG] and the nearby rs17674580[CT/TT] occurred more frequently in cases (79% and 68%) than controls (77% and 55%). The portion of GSTM1 negative bladder cancer patients is comparable with portions reported from other industrialized areas like Lutherstadt Wittenberg/Germany (58%), Dortmund/Germany (70%), Brescia/Italy (66%) or an occupational case-control series in Germany (56%). Data indicate that GSTM1 is a susceptibility factor for environmentally triggered bladder cancer rather than for smoking-mediated bladder cancer.

Sequence variant at 4q25 near PITX2 associates with appendicitis

Appendicitis is one of the most common conditions requiring acute surgery and can pose a threat to the lives of affected individuals. We performed a genome-wide association study of appendicitis in 7,276 Icelandic and 1,139 Dutch cases and large groups of controls. In a combined analysis of the Icelandic and Dutch data, we detected a single signal represented by an intergenic variant rs2129979 [G] close to the gene PITX2 associating with increased risk of appendicitis (OR = 1.15, P = 1.8 × 10-11). We only observe the association in patients diagnosed in adulthood. The marker is close to, but distinct from, a set of markers reported to associate with atrial fibrillation, which have been linked to PITX2. PITX2 has been implicated in determination of right-left symmetry during development. Anomalies in organ arrangement have been linked to increased prevalence of gastrointestinal and intra-abdominal complications, which may explain the effect of rs2129979 on appendicitis risk.

Identification of a Novel UT-B Urea Transporter in Human Urothelial Cancer

The urea transporter UT-B is widely expressed and has been studied in erythrocyte, kidney, brain and intestines. Interestingly, UT-B gene has been found more abundant in bladder than any other tissue. Recently, gene analyses demonstrate that SLC14A1 (UT-B) gene mutations are associated with bladder cancer, suggesting that urea transporter UT-B may play an important role in bladder carcinogenesis. In this study, we examined UT-B expression in bladder cancer with human primary bladder cancer tissues and cancer derived cell lines. Human UT-B has two isoforms. We found that normal bladder expresses long form of UT-B2 but was lost in 8 of 24 (33%) or significantly downregulated in 16 of 24 (67%) of primary bladder cancer patients. In contrast, the short form of UT-B1 lacking exon 3 was detected in 20 bladder cancer samples. Surprisingly, a 24-nt in-frame deletion in exon 4 in UT-B1 (UT-B1Δ24) was identified in 11 of 20 (55%) bladder tumors. This deletion caused a functional defect of UT-B1. Immunohistochemistry revealed that UT-B protein levels were significantly decreased in bladder cancers. Western blot analysis showed a weak UT-B band of 40 kDa in some tumors, consistent with UT-B1 gene expression detected by RT-PCR. Interestingly, bladder cancer associate UT-B1Δ24 was barely sialylated, reflecting impaired glycosylation of UT-B1 in bladder tumors. In conclusion, SLC14A1 gene and UT-B protein expression are significantly changed in bladder cancers. The aberrant UT-B expression may promote bladder cancer development or facilitate carcinogenesis induced by other carcinogens.

Genetic prediction of male pattern baldness

Male pattern baldness can have substantial psychosocial effects, and it has been phenotypically linked to adverse health outcomes such as prostate cancer and cardiovascular disease. We explored the genetic architecture of the trait using data from over 52,000 male participants of UK Biobank, aged 40-69 years. We identified over 250 independent genetic loci associated with severe hair loss (P<5x10-8). By splitting the cohort into a discovery sample of 40,000 and target sample of 12,000, we developed a prediction algorithm based entirely on common genetic variants that discriminated (AUC = 0.78, sensitivity = 0.74, specificity = 0.69, PPV = 59%, NPV = 82%) those with no hair loss from those with severe hair loss. The results of this study might help identify those at greatest risk of hair loss, and also potential genetic targets for intervention.

The Functional Haplotypes of CHRM3 Modulate mRNA Expression and Associate with Bladder Cancer among a Chinese Han Population in Kaohsiung City

Bladder cancer is one of the major cancer types and both environmental factors and genetic background play important roles in its pathology. Kaohsiung is a high industrialized city in Taiwan, and here we focused on this region to evaluate the genetic effects on bladder cancer. Muscarinic acetylcholine receptor M3 (CHRM3) was reported as a key receptor in different cancer types. CHRM3 is located at 1q42-43 which was reported to associate with bladder cancer. Our study attempted to delineate whether genetic variants of CHRM3 contribute to bladder cancer in Chinese Han population in south Taiwan. Five selected SNPs (rs2165870, rs10802789, rs685550, rs7520974, and rs3738435) were genotyped for 30 bladder cancer patients and 60 control individuals and genetic association studies were performed. Five haplotypes (GTTAT, ATTGT, GCTAC, ACTAC, and ACCAC) were found significantly associated with low CHRM3 mRNA level and contributed to increased susceptibility of bladder cancer in Kaohsiung city after rigid 10000 consecutive permutation tests. To our knowledge, this is the first genetic association study that reveals the genetic contribution of CHRM3 gene in bladder cancer etiology.

HNF1B variants associate with promoter methylation and regulate gene networks activated in prostate and ovarian cancer

Two independent regions within HNF1B are consistently identified in prostate and ovarian cancer genome-wide association studies (GWAS); their functional roles are unclear. We link prostate cancer (PC) risk SNPs rs11649743 and rs3760511 with elevated HNF1B gene expression and allele-specific epigenetic silencing, and outline a mechanism by which common risk variants could effect functional changes that increase disease risk: functional assays suggest that HNF1B is a pro-differentiation factor that suppresses epithelial-to-mesenchymal transition (EMT) in unmethylated, healthy tissues. This tumor-suppressor activity is lost when HNF1B is silenced by promoter methylation in the progression to PC. Epigenetic inactivation of HNF1B in ovarian cancer also associates with known risk SNPs, with a similar impact on EMT. This represents one of the first comprehensive studies into the pleiotropic role of a GWAS-associated transcription factor across distinct cancer types, and is the first to describe a conserved role for a multi-cancer genetic risk factor.

The Kidd (JK) Blood Group System

The Kidd blood group system was discovered in 1951 and is composed of 2 antithetical antigens, Jk^a and Jk^b, along with a third high-incidence antigen, Jk3. The Jk3 antigen is expressed in all individuals except those with the rare Kidd-null phenotype. Four Kidd phenotypes are therefore possible: Jk(a+b-), Jk(a-b+), Jk(a+b+), and Jk(a-b-). The glycoprotein carrying the Kidd antigens is a 43-kDa, 389-amino acid protein with 10 membrane-spanning domains which functions as a urea transporter on endothelial cells of the renal vasa recta as well as erythrocytes. The HUT11/UT-B/JK (SLC14A1) gene encoding this glycoprotein is located on chromosome 18q12-q21. The Jk^a and Jk^b antigens are the result of a single-nucleotide polymorphism present at nucleotide 838 resulting in an aspartate or asparagine amino acid at position 280, respectively. The Kidd blood group can create several difficult transfusion situations. Besides the typical acute hemolytic transfusion reactions common to all clinically relevant blood group antigens, the Kidd antigens are notorious for causing delayed hemolytic transfusion reactions due to the strong anamnestic response exhibited by antibodies directed against Kidd antigens. The Kidd-null phenotype is extremely rare in most ethnic groups, but is clinically significant due to the ability of those with the Kidd-null phenotype to produce antibodies directed against the high-incidence Jk3 antigen. Anti-Jk3 antibodies behave in concordance with anti-Jk^a or anti-Jk^b possessing the capability to cause both acute and delayed hemolytic reactions. Antibodies against any of the 3 Kidd antigens can also be a cause of hemolytic disease of the fetus and newborn, although this is generally mild. In this review, we will outline the makeup of the Kidd system from its historical discovery to the details of the Kidd gene and glycoprotein, and then discuss the practical aspects of Kidd antibodies and transfusion reactions with an extended focus on the Kidd-null phenotype. We will end with a brief discussion of the donor aspects related to the screening and supply management of blood from donors with the rare Jk(a-b-) phenotype.

Overexpression of Functional SLC6A3 in Clear Cell Renal Cell Carcinoma

Purpose: Renal cell carcinoma (RCC) is derived from a tissue with a remarkable capacity for vectorial transport. We therefore performed an unbiased exploration of transporter proteins in normal kidney and kidney cancer to discover novel clinical targets.Experimental Design: Using The Cancer Genome Atlas (TCGA) database, we investigated differences in membrane transporter expression in clear cell RCC (ccRCC) and normal kidney. We identified the dopamine transporter SLC6A3 as a specific biomarker for ccRCC. To investigate the functionality of SLC6A3, we used a [³H]-dopamine uptake assay on ccRCC cells. We further explored the effect of hypoxia-inducible factor (HIF) proteins on SLC6A3 expression by introducing siRNA in ccRCC cells and by hypoxic treatment of nonmalignant cells.Results: We show that ccRCC expresses very high transcript levels of SLC6A3 in contrast to normal kidney tissue and other tumor types, which do not express appreciable levels of this transporter. Importantly, we demonstrate that the elevated expression of SLC6A3 in ccRCC cells is associated with specific uptake of dopamine. By targeting the expression of HIF-1α and HIF-2α, we could show that SLC6A3 expression is primarily influenced by HIF-2α and that hypoxia can induce SLC6A3 expression in normal renal cells.Conclusions: We conclude that the dopamine transporter SLC6A3 constitutes a novel biomarker that is highly specific for ccRCC. We further postulate that the protein can be exploited for diagnostic or therapeutic purposes for detection or treatment of ccRCC. Clin Cancer Res; 23(8); 2105-15. ©2016 AACR.

Pathway analysis of bladder cancer genome-wide association study identifies novel pathways involved in bladder cancer development

Genome-wide association studies (GWAS) are designed to identify individual regions associated with cancer risk, but only explain a small fraction of the inherited variability. Alternative approach analyzing genetic variants within biological pathways has been proposed to discover networks of susceptibility genes with additional effects. The gene set enrichment analysis (GSEA) may complement and expand traditional GWAS analysis to identify novel genes and pathways associated with bladder cancer risk. We selected three GSEA methods: Gen-Gen, Aligator, and the SNP Ratio Test to evaluate cellular signaling pathways involved in bladder cancer susceptibility in a Texas GWAS population. The candidate genetic polymorphisms from the significant pathway selected by GSEA were validated in an independent NCI GWAS. We identified 18 novel pathways (P < 0.05) significantly associated with bladder cancer risk. Five of the most promising pathways (P ≤ 0.001 in any of the three GSEA methods) among the 18 pathways included two cell cycle pathways and neural cell adhesion molecule (NCAM), platelet-derived growth factor (PDGF), and unfolded protein response pathways. We validated the candidate polymorphisms in the NCI GWAS and found variants of RAPGEF1, SKP1, HERPUD1, CACNB2, CACNA1C, CACNA1S, COL4A2, SRC, and CACNA1C were associated with bladder cancer risk. Two CCNE1 variants, rs8102137 and rs997669, from cell cycle pathways showed the strongest associations; the CCNE1 signal at 19q12 has already been reported in previous GWAS. These findings offer additional etiologic insights highlighting the specific genes and pathways associated with bladder cancer development. GSEA may be a complementary tool to GWAS to identify additional loci of cancer susceptibility.