Genetic polymorphisms may explain association between alcohol consumption and bladder cancer risk in East Asian men

Gut and bladder fermentation syndromes: a narrative review

We recently reported the first clinical case of bladder fermentation syndrome (BFS) or urinary auto-brewery syndrome, which caused the patient to fail abstinence monitoring. In BFS, ethanol is generated by Crabtree-positive fermenting yeast Candida glabrata in a patient with poorly controlled diabetes. One crucial characteristic of BFS is the absence of alcoholic intoxication, as the bladder lumen contains transitional epithelium with low ethanol permeability. In contrast, patients with gut fermentation syndrome (GFS) or auto-brewery syndrome can spontaneously develop symptoms of ethanol intoxication even without any alcohol ingestion because of alcoholic fermentation in the gut lumen. In abstinence monitoring, a constellation of laboratory findings with positive urinary glucose and ethanol, negative ethanol metabolites, and the presence of yeast in urinalysis should raise suspicion for BFS, whereas endogenous ethanol production needs to be shown by a carbohydrate challenge test for GFS diagnosis. GFS patients will also likely fail abstinence monitoring because of the positive ethanol blood testing. BFS and GFS are treated by yeast eradication of fermenting microorganisms with antifungals (or antibiotics for bacterial GFS cases) and modification of underlying conditions (diabetes for BFS and gut dysbiosis for GFS). The under-recognition of these rare medical conditions has led to not only harm but also adverse legal consequences for patients, such as driving under the influence (DUI). GFS patients may be at risk of various alcohol-related diseases.

Association Between Alcohol Consumption and Risk of Bladder Cancer: A Dose-Response Meta-Analysis of Prospective Cohort Studies

Background

Controversial results of the association between alcohol consumption and risk of bladder cancer were reported by the previous meta-analyses.

Objective

To quantitatively investigate the association between alcohol consumption and risk of bladder cancer based on prospective cohort studies, and explore whether there is potential dose-response relation.

Method

PubMed, EMBASE, the Cochrane Library databases, China Biology Medicine disc (CBM), and Chinese National Knowledge Infrastructure (CNKI) were searched for relevant studies. Categorical meta-analysis was performed for risk estimates of any alcohol consumers versus non-drinkers as well as different drinking degrees (light, moderate, and heavy) versus none. And two-stage generalized least-squares regression and restricted cubic spline, as well as fixed-effects dose-response models, were used for linear and nonlinear dose-response relation exploration.

Results

9 prospective cohort studies including 1,971,396 individuals were finally included. We did not observe a significant association between alcohol intake and the risk of bladder cancer in the entire population. Linear association was detected in those who consumed alcohol from liquor or spirits (P _linear=0.02). One drink increment each day of alcohol could elevate the risk of bladder cancer by 9% (RR=1.09; 95%CI: 1.01-1.17). Alcohol was a risk factor of bladder cancer for male drinkers (RR=1.23; 95%CI: 1.13-1.35; I²=3.7%), while none linear or nonlinear relation was found.

Conclusion

No significant association between alcohol consumption and bladder cancer risk was found in the entire population, but there was a linear dose-response relation in those who consume alcohol from liquor or spirits. Alcohol may elevate the risk of bladder cancer in males in a dose-independent way.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, PROSPERO (CRD42020216195).

Characterization of mRNA Expression and Endogenous RNA Profiles in Bladder Cancer Based on The Cancer Genome Atlas (TCGA) Database

Background

Bladder cancer is a multifactorial disease with increasing incidence and mortality. Genetic alterations and altered expressions of mRNAs, long non-coding RNAs (lncRNAs), and miRNAs have been shown to play important roles in the tumorigenesis of bladder cancer. However, the functions of key RNAs and their regulatory network in bladder cancer are still to be elucidated.

Material/Methods

RNA profiles were downloaded from The Cancer Genome Atlas (TCGA) database. The differentially expressed mRNAs, lncRNAs, and miRNAs in bladder cancer were acquired through analyses of data from 414 bladder cancer tissues and 19 normal bladder tissues. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis was performed by using “DAVID6.8” and the R package “ClusterProfile”. Protein–protein interaction and competing endogenous RNA (ceRNA) networks were constructed by using “STRING” database and Cytoscape 3.6.2. Based on the clinical data and Cox regression, a prognosis model was established, and survival analysis was performed.

Results

A total of 1819 mRNAs, 659 lncRNAs, and 160 miRNAs were identified as significantly differentially expressed in bladder cancer of which 52 mRNAs, 58 lncRNAs, and 22 miRNAs were incorporated in the ceRNA network. CFL2 and TPM2 were found to be downregulated and showed significant correlation to each other in bladder cancer. HOXB5 and 6 lncRNAs (ADAMTS9-AS1, AC112721.1, LINC00460, AC110491.1, LINC00163, and HCG22) were strongly associated with high-grade, disease stages, and overall survival.

Conclusions

In this study, we have identified differentially expressed mRNAs, lncRNAs, and miRNAs in bladder cancer which were strongly associated with oncogenesis and prognosis. Further experimental studies are necessary to validate these results.