Occupational risk factors for relapse-free survival in bladder cancer patients

Intradermal and transdermal absorption of beta-naphthylamine and N-Phenyl-beta-naphthylamine in a viable human skin model

Technical products containing N-Phenyl-beta-naphthylamine (PBNA) are contaminated with beta-naphthylamine (BNA), a known carcinogen. Both amines penetrate the skin to different degrees, but little is known about their dermal-depot formation. This study investigated the dermal penetration of PBNA and its degradation product BNA using a viable human-skin model. PBNA (259 μg) or BNA (0.52 μg) in n-hexane and industrial grease were applied to freshly excised human skin (n = 6, 0.64 cm2) for 2-72 h. After temporary/continuous and single/repeated exposure, samples were taken (stratum corneum, epidermis/dermis, receptor fluid) and analyzed for their amine content by GC-MS. Continuous exposure led to a PBNA dermal depot of ∼47 μg/cm2 over 72 h. Temporary applications also resulted in lower but consistent PBNA dermal depots. A single 2-h application resulted in a dermal depot of ∼16 μg/cm2 after 72 h, while this was ∼25 μg/0.64 cm2 with repeated applications. BNA behaved differently; with repeated 2-h applications, intradermally retained BNA initially increased 3-6 fold, then dropped to ∼200-250 ng/cm2. This incomplete decline upon repeated short-term exposure to PBNA suggests that a BNA dermal depot is formed either due to contamination of PBNA with BNA or to enzymatic conversion of PBNA to BNA. Additionally, PBNA dermal depots were saturable under the given conditions. These findings highlight the importance of understanding the dermal-exposure dynamics of potential carcinogenic compounds in industrial settings.

Bladder cancer course, four genetic high-risk variants, and histopathological findings

Urinary bladder cancer, a smoking and occupation related disease, was subject of several genome-wide association studies (GWAS). However, studies on the course of the disease based on GWAS findings differentiating between muscle invasive bladder cancer (MIBC) and non-muscle invasive bladder cancer (NMIBC) are rare. Thus we investigated 4 single nucleotide polymorphisms (SNPs) detected in GWAS, related to the genes coding for TACC3 (transforming, acidic coiled-coil containing protein 3), for FGFR3 (fibroblast growth factor receptor 3), for PSCA (prostate stem cell antigen) and the genes coding for CBX6 (chromobox homolog 6) and APOBEC3A (apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like 3A). This study is based on 712 bladder cancer patients and 875 controls from 3 different case control studies in Germany. The 4 SNPs of interest (PSCA rs2294008 and rs2978974, FGFR3-TACC3 rs798766, and CBX6-APOBEC3A rs1014971) were determined by real-time polymerase chain reaction. The distribution of the 4 SNPs does not vary significantly between cases and controls in the entire study group and in the 3 local subgroups, including two former highly industrialized areas and a region without such history. Also, no significant differences in the bladder cancer subgroups of MIBC and NMIBC were observed. The 4 investigated SNPs do not noticeably contribute differently to the bladder cancer risk for the bladder cancer subgroups of MIBC and NMIBC.

lncRNA MORT Regulates Bladder Cancer Behaviors by Downregulating MicroRNA-146a-5p

BACKGROUND

Long noncoding RNAs (lncRNAs) are involved in the progression of various cancers. lncRNA MORT is downregulated in bladder cancer, while its function in this disease is unknown.

METHODS

lncRNA MORT and miR-146a-5p expression in 56 bladder cancer patients was detected by RT-qPCR. Correlations between MORT and miR-146a-5p were analyzed by Pearson's correlation coefficient. CCK-8 and flow transwell assays were applied to examine the behavioral changes in HT-1197 and HT-1376.

RESULTS

We found that miR-146a-5p was upregulated, while lncRNA MORT was downregulated in bladder cancer. miR-146a-5p and MORT were inversely and significantly correlated in tumor tissues. Overexpression of miR-146a-5p promoted, while overexpression of lncRNA MORT inhibited the invasion, migration, and proliferation of cells of bladder cancer cell lines. In addition, overexpression of lncRNA MORT inhibited miR-146a-5p; miR-146a-5p overexpression failed to significantly affect lncRNA MORT expression but attenuated its inhibitory effects on cancer cell behaviors.

CONCLUSION

lncRNA MORT may regulate bladder cancer cell behaviors by downregulating miR-146a-5p.

Lifestyle and Non-muscle Invasive Bladder Cancer Recurrence, Progression, and Mortality: Available Research and Future Directions

BACKGROUND:

A broad, comprehensive review of studies exploring associations between lifestyle factors and non-muscle invasive bladder cancer (NMIBC) outcomes is warranted to consolidate recommendations and identify gaps in research.

OBJECTIVE:

To summarize the literature on associations between lifestyle factors and clinical outcomes among patients with NMIBC.

METHODS:

PubMed was systematically queried for articles published through March 2019 regarding lifestyle factors and recurrence, progression, cancer-specific mortality, and all-cause mortality among patients with NMIBC.

RESULTS:

Notwithstanding many ambiguities, there is good-quality evidence suggesting a benefit of smoking avoidance/cessation, healthy body mass index (BMI), and type II diabetes mellitus prevention and treatment. Lactobacillus casei probiotic supplementation may reduce recurrence. There have been individual studies suggesting a benefit for uncooked broccoli and supplemental vitamin E as well as avoidance of supplemental vitamin B9, areca nut chewing, and a “Western diet” pattern high in fried foods and red meat. Additional studies do not suggest associations between NMIBC outcomes and use of fibrin clot inhibitors; insulin and other oral hypoglycemics; statins; supplemental selenium, vitamin A, vitamin C, and vitamin B6; fluid intake and intake of specific beverages (e.g., alcohol, coffee, green tea, cola); various dietary patterns (e.g., Tex-Mex, high fruit and vegetable, low-fat); and occupational and chemical exposures.

CONCLUSIONS:

Despite a myriad of publications on lifestyle factors and NMIBC, a need remains for research on unexplored associations (e.g., physical activity) and further studies that can elucidate causal effects. This would inform future implementation strategies for healthy lifestyle change in NMIBC patients.

Identification of interactions of binary variables associated with survival time using survivalFS

Many medical studies aim to identify factors associated with a time to an event such as survival time or time to relapse. Often, in particular, when binary variables are considered in such studies, interactions of these variables might be the actual relevant factors for predicting, e.g., the time to recurrence of a disease. Testing all possible interactions is often not possible, so that procedures such as logic regression are required that avoid such an exhaustive search. In this article, we present an ensemble method based on logic regression that can cope with the instability of the regression models generated by logic regression. This procedure called survivalFS also provides measures for quantifying the importance of the interactions forming the logic regression models on the time to an event and for the assessment of the individual variables that take the multivariate data structure into account. In this context, we introduce a new performance measure, which is an adaptation of Harrel's concordance index. The performance of survivalFS and the proposed importance measures is evaluated in a simulation study as well as in an application to genotype data from a urinary bladder cancer study. Furthermore, we compare the performance of survivalFS and its importance measures for the individual variables with the variable importance measure used in random survival forests, a popular procedure for the analysis of survival data. These applications show that survivalFS is able to identify interactions associated with time to an event and to outperform random survival forests.

Impact of Occupational Exposures and Genetic Polymorphisms on Recurrence and Progression of Non-Muscle-Invasive Bladder Cancer

Introduction: Additional or better markers are needed to guide the clinical monitoring of patients with non-muscle-invasive bladder cancer (NMIBC). Aim: To investigate the influence of occupational exposures and genetic polymorphisms on recurrence and progression of NMIBC. Methods: The study includes 160 NMIBC patients. We collected on questionnaire information on demographic variables, lifetime smoking history, lifetime history of occupational exposure to aromatic amines and polycyclic aromatic hydrocarbons. Genetic polymorphism (glutathione S-transferase M1; T1; P1 (GSTM1; GSTT1; GSTP1); N-acetyltransferase 1; 2 (NAT1; NAT2); cytochrome P450 1B1 (CYP1B1); sulfotransferase 1A1 (SULT1A1); myeloperoxidase (MPO); catechol-O-methyltransferase (COMT); manganese superoxide dismutase (MnSOD); NAD(P)H:quinone oxidoreductase (NQO1); X-ray repair cross-complementing group 1; 3 (XRCC1; XRCC3) and xeroderma pigmentosum complementation group (XPD)) was assessed in peripheral blood lymphocytes. DNA adducts were evaluated by 32P-postlabeling. Predictors of recurrence (histological confirmation of a newly found bladder tumor) and progression (transition of tumor from low-grade to high-grade and/or increase in TNM stage) were identified by multivariate Cox proportional hazard regression with stepwise backward selection of independent variables. Hazard ratios (HR) with 95% confidence interval (95%CI) and two-tail probability of error (p-value) were estimated. Results: The risk of BC progression decreased with the homozygous genotype “ValVal” of both COMT and MnSOD (HR = 0.195; 95%CI = 0.060 to 0.623; p = 0.006). The results on BC recurrence were of borderline significance. No occupational exposure influenced recurrence or progression. Conclusion: Our results are supported by experimental evidence of a plausible mechanism between cause (ValVal genotype of both MnSOD and COMT) and effect (decreased progression of tumor in NMIBC patients). The genetic polymorphisms associated with better prognosis may be used in clinic to guide selection of treatment for patients initially diagnosed with NMIBC. However, external validation studies are required.

Micro-brushing-based technique to gain fresh urothelial cells for gene expression analysis

The gold standard of saving fresh tissue in liquid nitrogen has some serious disadvantages in that this process is not available in daily medical routine practices even in many tumor centers. Our approach of a new minimally invasive technique is obtaining urothelial cells via micro-brushing the urinary bladder on the occasion of urological routine methods such as transurethral resection (TUR). Urothelial cells were obtained from 25 patients via two different micro-brushes from tumor tissue and from macroscopically healthy tissue during TUR. These cells were immediately transferred into RNA stabilization reagent and stored at -20°C. Later, mRNA was isolated, transcribed into cDNA, and amplified. cDNA was stored at -20°C until analysis. The mean RNA quantity was 99.5 ng/μl from tumor tissues and 66.3 ng/μl from macroscopically tumor-free tissue, enabling a considerable number of analyses. The quality of the gained cDNA allowed semi-quantitative PCR analysis of GSTM1 expression as well as quantitative PCR analysis of c-Myc expression. The new technique presents several important advantages. First, staging and grading of the stained tumor sample can be examined immediately, whereas fresh frozen sample is not examined until some days later. Further, this method can be applied in hospitals with no access to liquid nitrogen or without capability to provide an additional examination of frozen tumor sample by a pathologist. This presented minimally invasive method enables investigation of gene expression in the urinary bladder without disadvantages of the need for storage of fresh tissues in liquid nitrogen.