Comparing the joint effect of arsenic exposure, cigarette smoking and risk genotypes of vascular endothelial growth factor on upper urinary tract urothelial carcinoma and bladder cancer

Amelioration potential of Moringa oleifera extracts against sodium arsenate induced embryotoxicity and genotoxicity in mouse (Mus musculus)

Previous studies have suggested that arsenic crosses the placenta and affects the fetus development. The study under consideration aims to show comparative ameliorative effect of Moringa oleifera leaf and flower extracts against sodium arsenate induced fetus toxicity of mice. Pregnant mice (N=44) were kept in lab and divided into eleven group from (A to K) and were orally administered the doses 6 mg/kg, 12 mg/kg for sodium arsenate, 150 mg/kg and 300 mg/kg for Moringa oleifera leaf extracts (MOLE) and 150 mg/kg and 300 mg/kg for Moringa oleifera flower extracts (MOFE) comparing with control. The investigation revealed evident reduction in the fetuses weight, hind limb, fore limb, tail and snout length, crown rump and head circumferences well as malformations in tail, feet, arms, legs, skin and eyes in the negative control group (only administered with sodium arsenate). Co-administration of sodium arsenate with MOLE and MOFE ameliorate the reversed effect of sodium arsenate on the shape, length, body weight and DNA damage of fetus significantly at 95% confidence interval. However, Moringa oleifera leaf extract showed more significant results in comparison to Moringa oleifera flower extract. Hence concluded that Moringa oleifera leaf extract ameliorated the embryo toxic effects of sodium arsenate and can be used against environmental teratogens.

Comparative analysis of patients with upper urinary tract urothelial carcinoma in black-foot disease endemic and non-endemic area

BACKGROUND

A high incidence of upper urinary tract urothelial carcinoma has been reported in the southwestern area of Taiwan, where arsenic water contamination was considered the main cause. However, there is no definite proof to show a correlation between arsenic water contamination and upper urinary tract urothelial carcinoma. To investigate the clinical and epidemiological features of patients with upper urinary tract urothelial carcinoma between arsenic water endemic and non-endemic areas, we analyzed patients in terms of characteristics, stratified overall survival, disease-free survival, and cancer-specific survival.

METHODS

The records of a total of 1194 patients diagnosed with upper urinary tract urothelial carcinoma were retrospectively reviewed. Clinical data and current medical status were collected from the medical records. Statistical analyses were performed to determine the clinical variables and stratified survival curves between endemic and non-endemic groups.

RESULTS

Female predominance was revealed in both endemic and non-endemic groups (male:female ratio = 1:1.2-1.4). No statistical differences were found in histological types, staging, and tumor size between the two groups. Nonetheless, patients with characteristics of aging and having end-stage renal disease were outnumbered in the non-endemic group, while a higher prevalence of previous bladder tumors and more ureteral tumors were found in the endemic group. Adjusted stratified cumulative survival curves suggested a poorer prognosis in endemic patients, especially in disease-free survival of early stage disease.

CONCLUSIONS

A higher mortality rate with more previous bladder cancer history and ureteral tumors was seen in patients with upper urinary tract urothelial carcinoma residing in the arsenic water contamination area. This may be attributed to the long-term carcinogenic effect of arsenic underground water.

Arsenic exposure increased expression of HOTAIR and LincRNA-p21 in vivo and vitro

Arsenic is an environmental contaminant, its multiple effects on human tend to increase the rate of disease, cancer and other health problems. Some of long non-coding RNAs (lncRNAs) can be induced in major cellular processes such as necrosis, proliferation, and mutation. While the toxicity of arsenic is well established, the association between arsenic exposure and long non-coding RNAs has not been studied enough. This study investigated the association between arsenic and the expression of HOTAIR and LincRNA-p21 in vivo and vitro. In epidemiological studies, the expression of HOTAIR and LincRNA-p21 was increased after long-term arsenic exposure. HOTAIR and LincRNA-p21 expression were positively linked to monomethylarsenic acid (MMA), dimethylarsenic acid (DMA), inorganic arsenic (iAs), total arsenic (tAs), and MMA% and negatively linked to secondary methylation index (SMI). In A549 cells, arsenic exposure resulted in enhanced HOTAIR and LincRNA-p21 expression dose-dependently. The expression of HOTAIR was considerably high in the presence of NaAsO₂ and MMA but showed no difference in DMA compared with control group. And LincRNA-p21 expression was increased in the presence of NaAsO₂, MMA, and DMA. The expression of HOTAIR and LincRNA-p21 induced by iAs was much higher than that induced by MMA and DMA. Compared with the control group, treatment of A549 cells with NaAsO₂/S-adenosylmethionine (SAM) and NaAsO₂/glutathione (GSH) combination increased HOTAIR and LincRNA-p21 expression. The expression of LincRNA-p21 in combination of NaAsO₂/GSH was significantly decreased compared with NaAsO₂ alone. Besides, in the presence of arsenic, both of HOTAIR and LincRNA-p21 were upregulated significantly when P53 was knocked down. We revealed that inorganic arsenic, its methylated metabolites, and arsenic metabolism efficiency affect the expression of HOTAIR and LincRNA-p21.

Association between VEGF gene promoter polymorphisms and bladder cancer: An updated meta-analysis

BACKGROUND

Vascular endothelial growth factor (VEGF) is the key regulator of angiogenesis in the development of various cancers. Previous studies have examined the relationship between VEGF gene promoter polymorphisms such as -2578C/A and -460C/T and bladder cancer risk; however, these results are inconclusive. Therefore, we performed this meta-analysis to investigate the association between VEGF gene promoter polymorphisms and bladder cancer risk.

METHODS

PubMed, Embase, Cochrane Library and Web of Science databases were searched for studies published before September 2018. The methodological quality assessment of included studies was performed based on the Newcastle-Ottawa Quality Scale (NOS). We conducted a systematic review and meta-analysis using both fixed- and random-effect model. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the strength of the relationship. In addition, the stability of our analysis was evaluated by heterogeneity, sensitivity, subgroup of ethnicity, and publication bias analysis.

RESULTS

We finally included 7 case-control studies with a total of 2412 bladder cancer patients and 3157 cancer-free controls. In Asian population with the VEGF -2578C/A polymorphism, significantly higher bladder cancer risks of 1.55 (95% CI = 1.25-1.93) and 1.53 (95% CI = 1.11-2.10) were found in the heterozygous model (AC vs CC) and the dominant model (AA + AC vs CC), respectively. Though there was no statistical association between VEGF -460C/T polymorphism and bladder cancer, a tendency to higher bladder cancer risk was observed in various genetic models (T vs C; TT vs CC; TC vs CC and TT + TC vs CC).

CONCLUSIONS

Our findings suggest that VEGF -2578C/A polymorphism might be a risk factor with a modest significance for bladder cancer only in Asian population. Further studies with a larger sample size and other functional polymorphisms are needed to explore the effects of VEGF gene on the risk of bladder cancer.

Proteomic characterization of arsenic and cadmium exposure in bladder cells

RATIONALE

Accumulating evidence has linked prolonged exposure to heavy metals to cancer occurrence in the urinary system. However, the specific biological mechanisms responsible for the association of heavy metals with the unusually high incidence of upper tract urothelial carcinoma in Taiwan are complex and incompletely understood.

METHODS

To elucidate the specific biological mechanism and identify molecular indicators of the unusually high association of upper tract urothelial carcinoma with heavy metal exposure, protein expression following the treatment of T24 human bladder carcinoma and RT4 human bladder papilloma cell line models with arsenic (As) and cadmium (Cd) was studied. Proteomic changes in these cell models were integrated with data from a human bladder cancer (BLCA) tissue proteome to identify possible protein indicators of heavy metal exposure.

RESULTS

After mass spectrometry based proteomic analysis and verification by Western blotting procedures, we identified 66 proteins that were up-regulated and 92 proteins that were down-regulated in RT4 cell extracts after treatment with As or Cd. Some 52 proteins were up-regulated and 136 proteins were down-regulated in T24 cell extracts after treatment with Cd. We further confirmed that down-expression of the PML (promyelocytic leukemia) protein was sustained for at least 75 days after exposure of bladder cells to As. Dysregulation of these cellular proteins by As was associated with three biological pathways. Immunohistochemical analyses of paraffin-embedded BLCA tissue slides confirmed that PML protein expression was decreased in BLCA tumor cells compared with adjacent noncancerous epithelial cells.

CONCLUSIONS

These data suggest that PML may play an important role in the pathogenesis of BLCA and may be an indicator of heavy metal exposure in bladder cells.

Association and risk of five miRNAs with arsenic-induced multiorgan damage

Chronic exposure to arsenic remains a major environmental public health concern worldwide, affecting hundreds of millions of people. Arsenic-induced multiorgan damage and miRNA expression changes after arsenic exposure have been determined, but their associations and risks have not been fully examined. In this study, we measured the expression levels of five miRNAs in plasma from control and arsenic poisoned populations, and we analyzed the relationship between miRNAs and multiorgan damage. The results clearly show that the upregulation of miR-155 expression can increase the risk of arsenic induced skin damage (OR = 10.55; 95% CI: 6.02, 18.47); further, there is a link between the expression of miR-21 (OR = 11.84; 95% CI: 5.34, 26.28) and miR-145 (OR = 2.39; 95% CI: 1.61, 3.55) and liver damage, and miR-191 and kidney damage (OR = 3.65; 95% CI: 1.49, 8.93). In addition, we analyzed the diagnostic value of miRNAs associated with specific organ damage in arsenic-induced multiorgan damage. It was found that the miR-155 has a certain diagnostic value in arsenic-induced skin damage (AUC = 0.83), miR-21 and miR-145 have diagnostic value for liver damage (AUC = 0.80, 0.81) and miR-191 has diagnostic value for kidney damage (AUC = 0.83). This study provides the first comprehensive assessment of the association and risk of five miRNAs with arsenic-induced multiorgan damage. The study can provide a scientific basis for further understanding the causes of arsenic-induced multiorgan damage, identification of possible biological markers, and improvement of targeted prevention and control strategies.

Changes in human peripheral blood mononuclear cell (HPBMC) populations and T-cell subsets associated with arsenic and polycyclic aromatic hydrocarbon exposures in a Bangladesh cohort

Exposures to environmental arsenic (As) and polycyclic aromatic hydrocarbons (PAH) have been shown to independently cause dysregulation of immune function. Little data exists on the associations between combined exposures to As and PAH with immunotoxicity in humans. In this work we examined associations between As and PAH exposures with lymphoid cell populations in human peripheral blood mononuclear cells (PBMC), as well as alterations in differentiation and activation of B and T cells. Two hundred men, participating in the Health Effects of Arsenic Longitudinal Study (HEALS) in Bangladesh, were selected for the present study based on their exposure to As from drinking water and their cigarette smoking status. Blood and urine samples were collected from study participants. We utilized multiparameter flow cytometry in PBMC to identify immune cells (B, T, monocytes, NK) as well as the T-helper (Th) cell subsets (Th1, Th2, Th17, and Tregs) following ex vivo activation. We did not find evidence of interactions between As and PAH exposures. However, individual exposures (As or PAH) were associated with changes to immune cell populations, including Th cell subsets. Arsenic exposure was associated with an increase in the percentage of Th cells, and dose dependent changes in monocytes, NKT cells and a monocyte subset. Within the Th cell subset we found that Arsenic exposure was also associated with a significant increase in the percentage of circulating proinflammatory Th17 cells. PAH exposure was associated with changes in T cells, monocytes and T memory (Tmem) cells and with changes in Th, Th1, Th2 and Th17 subsets all of which were non-monotonic (dose dependent). Alterations of immune cell populations caused by environmental exposures to As and PAH may result in adverse health outcomes, such as changes in systemic inflammation, immune suppression, or autoimmunity.

Assessment of arsenic and polycyclic aromatic hydrocarbon (PAH) exposures on immune function among males in Bangladesh

Arsenic and polycyclic aromatic hydrocarbons (PAH) are environmental pollutants to which people around the world are exposed through water, food and air. In mouse and in vitro studies of human cells, both of these chemicals have been shown to modulate the immune system. In some experimental studies, a synergistic disruption of immune function was observed by a combined exposure to arsenic and PAH. However, a joint effect of arsenic and PAH on immune function has not been studied in humans. We have conducted an epidemiological investigation to examine effects of chronic arsenic and PAH exposures on immune function. We assessed T-cell proliferation (TCP) and cytokine production of anti-CD3/anti-CD28 stimulated lymphocytes in human peripheral blood mononuclear cells (HPBMC) among 197 healthy men enrolled to the Health Effects of Arsenic Longitudinal (HEALS) cohort in Bangladesh. By design, approximately half were active smokers and the rest were never smokers. Our analyses demonstrated that IL-1b, IL-2, IL-4 and IL-6 were significantly stimulated as a function of urinary arsenic levels in models adjusted for age, body mass index (BMI), smoking status and PAH-DNA adducts. After correcting for false detection rate (FDR), only IL-1b remained statistically significant. We found a U-shaped dose response relationship between urinary arsenic and IL-1b. On the other hand, PAH-DNA adducts were associated with an inhibition of TCP and appeared as an inverted U-shape curve. Dose response curves were non-monotonic for PAH-DNA adduct exposures and suggested that cytokine secretion of IFNg, IL-1b, IL-2, IL-10 and IL17A followed a complex pattern. In the majority of donors, there was a trend towards a decrease in cytokine associated with PAH-DNA adducts. We did not observe any interaction between urinary arsenic and PAH-DNA adducts on immune parameters. Our results indicate that long-term exposures to arsenic and PAH have independent, non-monotonic associations with TCP and cytokine production.

Development and validation of a nomogram for urothelial cancer in patients with chronic kidney disease

Urothelial cancer (UC) is a common kidney cancer in Taiwan and patients with chronic kidney disease (CKD) are more at risk for UC than the general population. The diagnostic value of urine analysis and urine cytology is limited, especially in CKD patients. The aim of the study is to develop a nomogram to predict the risk of UC in CKD patients. We enrolled 169 UC patients and 1383 CKD patients from 9 hospitals in Taiwan between 2012 and 2015. CA125, HE4, clinical characteristics, and medical history were analyzed using multivariable logistic regression for its association with UC. A nomogram was developed to predict the risk of UC and was validated using Bootstrap. CA125 was associated with UC in CKD patients (OR: 5.91, 95% CI: 3.24–10.77) but HE4 was not (OR: 1.29, 95% CI: 0.67–2.35). A nomogram based on patients’ age, estimated glomerular filtration rate, CA125 (log transformed), smoking, exposure of environmental toxin, use of nonsteroid anti-inflammatory drugs, and use of traditional Chinese medicine was conducted. The AUC of the nomogram was 0.90 (95% CI: 0.86–0.92, p < 0.01). Serum CA125 may identify UC patients from CKD patients but has limited diagnostic value due to low sensitivity. The diagnostic value of serum CA125 level can be improved by the combination with clinical characteristics including age, renal function, and medical history.

Association between five polymorphisms in vascular endothelial growth factor gene and urinary bladder cancer risk: A systematic review and meta-analysis involving 6671 subjects

BACKGROUND

Vascular endothelial growth factor (VEGF) gene plays a key role in angiogenesis and tumor growth. The relationship between VEGF gene polymorphisms and bladder cancer (BCa) risk was studied extensively in recent years. However, the currently available results are controversial. To ascertain whether VEGF polymorphisms are associated with the susceptibility to BCa, we conducted this systematic review and meta-analysis.

MATERIALS AND METHODS

Relevant studies were collected systemically from PubMed, Medline, Embase, Web of Science databases and the Cochrane Library. Odds ratios (ORs) and 95% confidence intervals (CIs) were evaluated using random or fixed effects models by Stata statistical software. This systematic review protocol was registered at International prospective register of systematic reviews (PROSPERO) under number CRD42018099279.

RESULTS

A total of eight articles including twenty case-control studies with 3206 BCa cases and 3645 controls were enrolled for this meta-analysis. By pooling all eligible studies, we found that rs3025039, rs833052 and rs25648 polymorphisms were significantly associated with BCa risk. However, in subgroup analyses by stage, we identified a decreased association between the rs699947 A-allele and Muscle-invasive Bladder Cancer (MIBC) under allele contrast, homozygous and recessive genetic models (A vs C: OR = 0.76; AA vs CC: OR = 0.49, 95%CI = 0.27-0.90, I² = 0.0%, P = 0.021; AA vs CA + CC: OR = 0.60, 95%CI = 0.38-0.96, I² = 0.0%, P = 0.034). As to ethnicity subgroup analysis, rs699947 and rs3025039 polymorphisms were thought as a risk factor for BCa risk in Asian population, while a decreased association was revealed between rs699947 (C > A) A-allele and BCa risk in African population under dominant, recessive, homozygous, heterozygous and allele contrast genetic models. While for other polymorphisms, null results were found.

CONCLUSION

Our meta-analysis suggested that rs3025039 (C > T), rs833052 (C > A) and rs25648 (C > T) polymorphisms of VEGF gene increased susceptibility to BCa risk. And our study also demonstrated homozygous TT genotype in rs3025039, homozygous AA genotype in rs833052 and homozygous TT genotype in rs25648 were significantly relevant to elevated BCa risk. In the meanwhile, it is worth noting that rs699947 (C > A) A-allele should be thought as a protective factor for MIBC.

VEGF gene rs3025039C/T and rs833052C/A variants are associated with bladder cancer risk in Asian descendants

INTRODUCTION

Polymorphisms of vascular endothelial growth factor (VEGF) gene were evaluated in a number of studies to evaluate bladder cancer (BCa) susceptibility but with controversial conclusions.

MATERIAL AND METHODS

We performed a pooled analysis and used odds ratios (ORs) with corresponding 95% confidence intervals (95% CIs) to investigate the correlation between VEGF gene rs3025039C/T and rs833052C/A variants and risk of BCa. Furthermore, we utilized in silico tools to demonstrate the relationship of VEGF expression correlated with BCa susceptibility and survival time.

RESULTS

A total of eight studies including 4359 BCa patients and 5417 control subjects were enrolled in our study. For VEGF rs3025039C/T, a significant association was indicated between this variant and BCa risk in homozygote comparison (OR = 1.51; 95% CI = 1.13-2.02; P _{heterogeneity}  = 0.815) and recessive genetic model (OR = 1.49; 95% CI = 1.12-1.99; P _{heterogeneity}  = 0.874), in particular in an Asian population subgroup. For VEGF rs833052C/A, we observed a positive association between this variant and BCa susceptibility in Asian descendants. Results from in silico tool showed evidence that VEGF expression in bladder carcinoma tissue is higher than that in normal counterpart (transcripts per kilobase million = 7.21 vs 6.85; P < 0.05).

CONCLUSIONS

The VEGF gene rs3025039C/T and rs833052C/A variants may contribute to the risk of developing BCa, especially in Asian descendants. Future larger sample studies should be continued to focus on this issue in more detail.

A review on arsenic carcinogenesis: Epidemiology, metabolism, genotoxicity and epigenetic changes

Long-term exposure to arsenic (inorganic arsenic) is a world-wide environmental health concern. Arsenic is classified as the Group 1 human carcinogen by the International Agency for Research on Cancer (IARC). Epidemiological studies have established a strong association between inorganic arsenic (iAs) exposure in drinking water and an increased incidence of cancer including bladder, liver, lung, prostate, and skin cancer. iAs also increases the risk of other diseases such as cardiovascular disease, hypertension and diabetes. The molecular mechanisms of carcinogenesis of iAs remain poorly defined, several mechanisms have been proposed, including genotoxicity, altered cell proliferation, oxidative stress, changes to the epigenome, disturbances of signal transduction pathways, cytotoxicity and regenerative proliferation. In this article, we will summarize current knowledge on the mechanisms of arsenic carcinogenesis and focus on integrating all these issues to garner a broader perspective.

Association Between 12 Polymorphisms of VEGF/Hypoxia/Angiogenesis Pathway Genes and Risk of Urogenital Carcinomas: A Meta-Analysis Based on Case-Control Studies

Objective: Previous studies indicated potential associations between polymorphisms in genes of VEGF/hypoxia/angiogenesis pathway and risk of urogenital carcinomas However, the results were controversial and inconclusive. Here, we conducted an in-depth meta-analysis to investigate the precise associations between polymorphisms in VEGF/hypoxia/angiogenesis related genes and risk of urogenital carcinomas.

Methods: We searched PubMed, Web of Science, EMBASE, and Cochrane Library to identify all eligible publications. Pooled odds ratios (ORs) corresponding with the 95% confidence intervals (CIs) were calculated to evaluate their associations. Subgroup analysis was conducted to further ascertain such relationship and investigate sources of heterogeneity.

Results: In the end, a total of 96 case-control studies fulfilled the inclusion criteria were enrolled for 12 polymorphisms in 4 VEGF/hypoxia/angiogenesis related genes. The pooled results showed eNOS-rs2070744 polymorphism conferred a significantly increased overall risk of urogenital carcinomas in allele, homozygote, and recessive models, respectively. In addition, eNOS-Intron 4a/b VNTR polymorphism was identified related to an increased risk of urogenital carcinomas in recessive model. And VEGF-rs699947 polymorphism was also identified an increased risk of renal cell carcinoma (RCC) in allelic, heterozygote, dominant, homozygote, and recessive models.

Conclusion: To conclude, eNOS-rs2070744 and eNOS-Intron 4a/b VNTR polymorphisms are risk factors for urogenital carcinomas. VEGF-rs699947 polymorphism was also identified as an increased risk factor for renal carcinoma.

Environmental arsenic exposure: From genetic susceptibility to pathogenesis

More than 200 million people in 70 countries are exposed to arsenic through drinking water. Chronic exposure to this metalloid has been associated with the onset of many diseases, including cancer. Epidemiological evidence supports its carcinogenic potential, however, detailed molecular mechanisms remain to be elucidated. Despite the global magnitude of this problem, not all individuals face the same risk. Susceptibility to the toxic effects of arsenic is influenced by alterations in genes involved in arsenic metabolism, as well as biological factors, such as age, gender and nutrition. Moreover, chronic arsenic exposure results in several genotoxic and epigenetic alterations tightly associated with the arsenic biotransformation process, resulting in an increased cancer risk. In this review, we: 1) review the roles of inter-individual DNA-level variations influencing the susceptibility to arsenic-induced carcinogenesis; 2) discuss the contribution of arsenic biotransformation to cancer initiation; 3) provide insights into emerging research areas and the challenges in the field; and 4) compile a resource of publicly available arsenic-related DNA-level variations, transcriptome and methylation data. Understanding the molecular mechanisms of arsenic exposure and its subsequent health effects will support efforts to reduce the worldwide health burden and encourage the development of strategies for managing arsenic-related diseases in the era of personalized medicine.

Angiogenic activity in vivo of the particulate matter (PM10)

BACKGROUND

Particulate matter (PM) is the most efficient vehicle for the inhalation and absorption of toxic substances into the body.

METHOD

The present study was aimed at testing the hypothesis that PM10 samples collected on quartz filters exert an angiogenic activity in vivo in the chick embryo chorioallantoic membrane (CAM) assay.

RESULTS

When the low, medium, and high PM10 concentrations filters were tested in the CAM assay, an increasing number of microvessels was detectable after 4 days of applications of the filters. Moreover, at histological level, numerous microvessels and a dense inflammatory infiltrate were recognizable in the CAM mesenchyme.

CONCLUSION

Our data show a clear dose-response relationship between the dose variable (PM10 and Bap) and the outcome variable. So far, the PM10 target value is determined on the basis of regulatory agreements and is not health-based. In addition, the mere gravimetric measure of PM10 cannot be considered a fully reliable surrogate of the overall toxicity of the mixture.

Adjuvant radiotherapy for locally advanced upper tract urothelial carcinoma

There is relatively little literature on adjuvant radiotherapy after radical nephroureterectomy with bladder cuff excision (RNU) for patients with upper tract urothelial carcinoma (UTUC). This study was designed to determine the efficacy of adjuvant radiotherapy for patients with pT3N0M0 UTUC. We retrospectively reviewed 198 patients treated with RNU between December 2001 and January 2015. Postoperative radiotherapy was administered in 40 (20.2%) of patients. Patients who received radiotherapy were younger than those that did not (65.2 vs. 70.5 years, p = 0.023). With median follow up of 29.1 months, Kaplan-Meier analysis with the log-rank test demonstrated no significant differences between those omitting vs receiving adjuvant radiotherapy in regards to 2-year rates of overall survival (72.0% vs. 73.4%, p = 0.979), cancer-specific survival (73.2% vs. 75.3%, p = 0.844), and recurrence-free survival (61.2% vs. 66.3%, p = 0.742). However, in multivariable analysis with Cox regression, young age, absence of chronic kidney disease, negative lymphovascular invasion, negative surgical margin, and adjuvant chemotherapy were also associated with better cancer-specific survival. In conclusion, adjuvant radiotherapy did not offer any significant benefit in terms of overall, cancer-specific, and recurrence-free survivals in patients with pT3N0M0 UTUC after RNU. More effective systemic adjuvant chemotherapy is necessary to improve the outcome of these patients.

Quantified relations between exposure to tobacco smoking and bladder cancer risk: a meta-analysis of 89 observational studies

BACKGROUND

Smoking is a major risk factor for bladder cancer (BC). This meta-analysis updates previous reviews on smoking characteristics and BC risk, and provides a more quantitative estimation of the dose-response relationship between smoking characteristics and BC risk.

METHODS

In total, 89 studies comprising data from 57 145 BC cases were included and summary odds ratios (SORs) were calculated. Dose-response meta-analyses modelled relationships between smoking intensity, duration, pack-years and cessation and BC risk. Sources of heterogeneity were explored and sensitivity analyses were conducted to test the robustness of findings.

RESULTS

Current smokers (SOR = 3.14, 95% CI = 2.53-3.75) and former smokers(SOR = 1.83, 95% CI = 1.52-2.14) had an increased risk of BC compared with never smokers. Age at first exposure was negatively associated with BC risk. BC risk increased gradually by smoking duration and a risk plateau at smoking 15 cigarettes a day and 50 pack-years was observed. Smoking cessation is most beneficial from 20 years before diagnosis. The population-attributable risk of BC for smokers has decreased from 50% to 43% in men and from 35% to 26% in women from Europe since estimated in 2000. Results were homogeneous between sources of heterogeneity, except for lower risk estimates found in studies of Asian populations.

CONCLUSIONS

Active smokers are at an increased risk of BC. Dose-response meta-analyses showed a BC risk plateau for smoking intensity and indicate that even after long-term smoking cessation, an elevated risk of bladder cancer remains.

Joint Effect of Urinary Total Arsenic Level and VEGF-A Genetic Polymorphisms on the Recurrence of Renal Cell Carcinoma

The results of our previous study suggested that high urinary total arsenic levels were associated with an increased risk of renal cell carcinoma (RCC). Germline genetic polymorphisms might also affect cancer risk and clinical outcomes. Vascular endothelial growth factor (VEGF) plays an important role in vasculogenesis and angiogenesis, but the combined effect of these factors on RCC remains unclear. In this study, we explored the association between the VEGF-A -2578C>A, -1498T>C, -1154G>A, -634G>C, and +936C>T gene polymorphisms and RCC. We also evaluated the combined effects of the VEGF-A haplotypes and urinary total arsenic levels on the prognosis of RCC. This case-control study was conducted with 191 RCC patients who were diagnosed with renal tumors on the basis of image-guided biopsy or surgical resections. An additional 376 age- and gender-matched controls were recruited. Concentrations of urinary arsenic species were determined by a high performance liquid chromatography-linked hydride generator and atomic absorption spectrometry. Genotyping was investigated using fluorescent-based TaqMan allelic discrimination. We observed no significant associations between VEGF-A haplotypes and RCC risk. However, the VEGF-A ACGG haplotype from VEGF-A -2578, -1498, -1154, and -634 was significantly associated with an increased recurrence of RCC (OR = 3.34, 95% CI = 1.03–10.91). Urinary total arsenic level was significantly associated with the risk of RCC in a dose-response manner, but it was not related to the recurrence of RCC. The combination of high urinary total arsenic level and VEGF-A risk haplotypes affected the OR of RCC recurrence in a dose-response manner. This is the first study to show that joint effect of high urinary total arsenic and VEGF-A risk haplotypes may influence the risk of RCC recurrence in humans who live in an area without obvious arsenic exposure.

Functional role of inorganic trace elements in angiogenesis part III: (Ti, Li, Ce, As, Hg, Va, Nb and Pb)

Many essential elements exist in nature with significant influence on human health. Angiogenesis is vital in developmental, repair, and regenerative processes, and its aberrant regulation contributes to pathogenesis of many diseases including cancer. Thus, it is of great importance to explore the role of these elements in such a vital process. This is third in a series of reviews that serve as an overview of the role of inorganic elements in regulation of angiogenesis and vascular function. Here we will review the roles of titanium, lithium, cerium, arsenic, mercury, vanadium, niobium, and lead in these processes. The roles of other inorganic elements in angiogenesis were discussed in part I (N, Fe, Se, P, Au, and Ca) and part II (Cr, Si, Zn, Cu, and S) of these series. The methods of exposure, structure, mechanisms, and potential activities of these elements are briefly discussed. An electronic search was performed on the role of these elements in angiogenesis from January 2005 to April 2014. These elements can promote and/or inhibit angiogenesis through different mechanisms. The anti-angiogenic effect of titanium dioxide nanoparticles comes from the inhibition of angiogenic processes, and not from its toxicity. Lithium affects vasculogenesis but not angiogenesis. Nanoceria treatment inhibited tumor growth by inhibiting angiogenesis. Vanadium treatment inhibited cell proliferation and induced cytotoxic effects through interactions with DNA. The negative impact of mercury on endothelial cell migration and tube formation activities was dose and time dependent. Lead induced IL-8 production, which is known to promote tumor angiogenesis. Thus, understanding the impact of these elements on angiogenesis will help in development of new modalities to modulate angiogenesis under various conditions.

Risk of death from cardiovascular disease associated with low-level arsenic exposure among long-term smokers in a US population-based study

High levels of arsenic exposure have been associated with increases in cardiovascular disease risk. However, studies of arsenic's effects at lower exposure levels are limited and few prospective studies exist in the United States using long-term arsenic exposure biomarkers. We conducted a prospective analysis of the association between toenail arsenic and cardiovascular disease mortality using longitudinal data collected on 3939 participants in the New Hampshire Skin Cancer Study. Using Cox proportional hazard models adjusted for potential confounders, we estimated hazard ratios and 95% confidence intervals associated with the risk of death from any cardiovascular disease, ischemic heart disease, and stroke, in relation to natural-log transformed toenail arsenic concentrations. In this US population, although we observed no overall association, arsenic exposure measured from toenail clipping samples was related to an increased risk of ischemic heart disease mortality among long-term smokers (as reported at baseline), with increased hazard ratios among individuals with ≥ 31 total smoking years (HR: 1.52, 95% CI: 1.02, 2.27), ≥ 30 pack-years (HR: 1.66, 95% CI: 1.12, 2.45), and among current smokers (HR: 1.69, 95% CI: 1.04, 2.75). These results are consistent with evidence from more highly exposed populations suggesting a synergistic relationship between arsenic exposure and smoking on health outcomes and support a role for lower-level arsenic exposure in ischemic heart disease mortality.

Assessing the carcinogenic potential of low-dose exposures to chemical mixtures in the environment: focus on the cancer hallmark of tumor angiogenesis

One of the important 'hallmarks' of cancer is angiogenesis, which is the process of formation of new blood vessels that are necessary for tumor expansion, invasion and metastasis. Under normal physiological conditions, angiogenesis is well balanced and controlled by endogenous proangiogenic factors and antiangiogenic factors. However, factors produced by cancer cells, cancer stem cells and other cell types in the tumor stroma can disrupt the balance so that the tumor microenvironment favors tumor angiogenesis. These factors include vascular endothelial growth factor, endothelial tissue factor and other membrane bound receptors that mediate multiple intracellular signaling pathways that contribute to tumor angiogenesis. Though environmental exposures to certain chemicals have been found to initiate and promote tumor development, the role of these exposures (particularly to low doses of multiple substances), is largely unknown in relation to tumor angiogenesis. This review summarizes the evidence of the role of environmental chemical bioactivity and exposure in tumor angiogenesis and carcinogenesis. We identify a number of ubiquitous (prototypical) chemicals with disruptive potential that may warrant further investigation given their selectivity for high-throughput screening assay targets associated with proangiogenic pathways. We also consider the cross-hallmark relationships of a number of important angiogenic pathway targets with other cancer hallmarks and we make recommendations for future research. Understanding of the role of low-dose exposure of chemicals with disruptive potential could help us refine our approach to cancer risk assessment, and may ultimately aid in preventing cancer by reducing or eliminating exposures to synergistic mixtures of chemicals with carcinogenic potential.

Vascular endothelial growth factor polymorphisms as effect modifiers of oral squamous cell carcinoma risk: A systematic review and meta-analysis

Smoking is one of the main risk factors for the development of oral squamous cell carcinoma (OSCC). Smoking may affect single-nucleotide polymorphism (SNP)-dependent vascular endothelial growth factor (VEGF)-induced angiogenic activity. Therefore, we systematically reviewed the published VEGF-SNP genotype data of OSCC patients and healthy individuals and performed a meta-analysis comparing the VEGF-SNP genotypes of smoking and non-smoking patients in association with OSCC incidence. Prospective and retrospective studies on the clinical comparison of OSCC patients with different VEGF-SNP genotypes were reviewed. The meta-analysis re-pooled studies of smoking and non-smoking OSCC patients with different VEGF-SNPs between 2006 and 2014. The identified articles were reviewed and those reporting pertinent information, assignment to smoking and non-smoking patient groups and sufficient data for estimation of an odds ratio (OR) with a 95% confidence interval (CI) were selected for the meta-analysis. Pooled ORs and CIs for the comparison of SNP distribution in the smoking and non-smoking subgroups were calculated and compared using the random-effects model. A total of 7 studies were included in the systematic review, which was followed by a meta-analysis using 3 pertinent studies. The reviewed studies reported discrepant findings, with differences between Asian and European patients. The meta-analysis demonstrated marginal but not statistically significant differences, suggesting that specific VEGF-SNPs may be OSCC risk modifiers for smokers, depending on the ethnic background. The performed meta-analysis suggested an increased OSCC risk for smokers carrying specific VEGF-genotypes, although the calculated data did not reach the level of significance. However, data have to be interpreted with caution due to the limited sample size. Therefore, further studies, including larger patient samples, are mandatory.

Smoking-induced changes in cancer-related factors in patients with upper tract urothelial cancer

Cigarette smoking is a major risk factor for urothelial cancer (UC) development. However, the associations between smoking and changes in the pathological characteristics and molecular expression of cancer-related molecules in upper tract (UT) UC have not been fully elucidated. We investigated the associations between smoking status and cancer-related factors, including cancer cell proliferation, apoptosis, angiogenesis, lymphangiogenesis and expression of vascular endothelial growth factor-A and -C, matrix metalloproteinase (MMP)-2 and -9, cyclooxygenase (COX)-2 and urokinase-type plasminogen activator, in patients with UTUC. A total of 134 patients who underwent nephroureterectomy were retrospectively investigated. Proliferation index (PI), microvessel density and lymphatic vessel density (LVD) were measured using anti-Ki-67, anti-CD105 and anti-D2-40 antibodies in formalin-fixed specimens. The apoptotic index was evaluated using the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling method. Other cancer-related molecules were investigated by immunohistochemistry in similar specimens. The patients were divided into three groups; non-smoker (n=54, 40.3%), former smoker (n=46, 34.3%) and current smoker (n=34, 25.4%). The PI and the apoptotic index were not found to be correlated with smoking status; however, the mean/standard deviation level of LVD in current smokers (40.9/12.9) was significantly higher (P=0.034) compared to that in patients who had never smoked (34.4/10.6). In addition, smoking status was positively correlated with the presence of intratumoral lymphatic vessels (iLV) (P=0.010) and the expression of COX-2 and MMP-9 (P=0.032). The multivariate analysis demonstrated that current smoking was independently associated with all the abovementioned smoking-related factors. However, former smoking was correlated with LVD and the presence of iLV. In the survival analysis, LVD, the presence of iLV and the expression of COX-2 and MMP-9 were identified as predictive factors for metastasis following surgery. In conclusion, lymphangiogenesis and the expression levels of COX-2 and MMP-9 were found to be associated with the smoking status of UTUC patients. Our results may provide important insights into the pathological changes precipitated by smoking in these patients.

[Carcinogenic pathways and natural history of upper tract urothelial carcinomas: state-of-the-art review for the yearly scientific report of the French National Association of Urology]

OBJECTIVE

To describe natural history and carcinogenesis of upper tract urothelial carcinoma (UTUC).

METHODS

A systematic review of the scientific literature was performed in the Medline database (Pubmed) using different associations of the following keywords: upper tract urothelial carcinoma; clonality; carcinogenesis; mutation; chromosomal instability; Lynch syndrome; genetic polymorphism.

RESULTS

Local development of UTUC is characterized by a highly prevalent multifocality that might be explained by the overlap of "field change" and "intraluminal seeding and implantation" theories. UTUC and bladder tumors share common carcinogenesis mechanisms such as mutations of FGFR3 and TP53 defining two distinct pathways of pathogenesis. Epigenetic alterations corresponding to the hypermethylation of different promoters regulating genes expression and chromosomal instability such as chromosome 9 deletions are also involved in UTUC carcinogenesis. Furthermore, specific genetic risk factors fro UTUC including Lynch syndrome and different polymorphisms might explain an individual susceptibility for developing these tumors.

CONCLUSIONS

Significant advances have been done in the field of basic research in UTUCs in recent years and have been of particular interest to provide better descriptions of their natural history. Despite these important findings however, some carcinogenic mechanisms remains not elucidated and unknown in the field of UTUC so far.

Genome-wide methylation profiling and the PI3K-AKT pathway analysis associated with smoking in urothelial cell carcinoma

Urothelial cell carcinoma (UCC) is the second most common genitourinary malignant disease in the USA, and tobacco smoking is the major known risk factor for UCC development. Exposure to carcinogens, such as those contained in tobacco smoke, is known to directly or indirectly damage DNA, causing mutations, chromosomal deletion events and epigenetic alterations in UCC. Molecular studies have shown that chromosome 9 alterations and P53, RAS, RB and PTEN mutations are among the most frequent events in UCC. Recent studies suggested that continuous tobacco carcinogen exposure drives and enhances the selection of epigenetically altered cells in UCC, predominantly in the invasive form of the disease. However, the sequence of molecular events that leads to UCC after exposure to tobacco smoke is not well understood. To elucidate molecular events that lead to UCC oncogenesis and progression after tobacco exposure, we developed an in vitro cellular model for smoking-induced UCC. SV-40 immortalized normal HUC1 human bladder epithelial cells were continuously exposed to 0.1% cigarette smoke extract (CSE) until transformation occurred. Morphological alterations and increased cell proliferation of non-malignant urothelial cells were observed after 4 months (mo) of treatment with CSE. Anchorage-independent growth assessed by soft agar assay and increase in the migratory and invasive potential was observed in urothelial cells after 6 mo of CSE treatment. By performing a PCR mRNA expression array specific to the PI3K-AKT pathway, we found that 26 genes were upregulated and 22 genes were downregulated after 6 mo of CSE exposure of HUC1 cells. Among the altered genes, PTEN, FOXO1, MAPK1 and PDK1 were downregulated in the transformed cells, while AKT1, AKT2, HRAS, RAC1 were upregulated. Validation by RT-PCR and western blot analysis was then performed. Furthermore, genome-wide methylation analysis revealed MCAM, DCC and HIC1 are hypermethylated in CSE-treated urothelial cells when compared with non-CSE exposed cells. The methylation status of these genes was validated using quantitative methylation-specific PCR (QMSP), confirming an increase in methylation of CSE-treated urothelial cells compared to untreated controls. Therefore, our findings suggest that a tobacco signature could emerge from distinctive patterns of genetic and epigenetic alterations and can be identified using an in vitro cellular model for the development of smoking-induced cancer.