Relationship between schistosomiasis and bladder cancer

Bladder cancer: a simple model becomes complex

Bladder cancer is one of the most frequent malignancies in developed countries and it is also characterized by a high number of recurrences. Despite this, several authors in the past reported that only two altered molecular pathways may genetically explain all cases of bladder cancer: one involving the FGFR3 gene, and the other involving the TP53 gene. Mutations in any of these two genes are usually predictive of the malignancy final outcome. This cancer may also be further classified as low-grade tumors, which is always papillary and in most cases superficial, and high-grade tumors, not necessarily papillary and often invasive. This simple way of considering this pathology has strongly changed in the last few years, with the development of genome-wide studies on expression profiling and the discovery of small non-coding RNA affecting gene expression. An easy search in the OMIM (On-line Mendelian Inheritance in Man) database using "bladder cancer" as a query reveals that genes in some way connected to this pathology are approximately 150, and some authors report that altered gene expression (up- or down-regulation) in this disease may involve up to 500 coding sequences for low-grade tumors and up to 2300 for high-grade tumors. In many clinical cases, mutations inside the coding sequences of the above mentioned two genes were not found, but their expression changed; this indicates that also epigenetic modifications may play an important role in its development. Indeed, several reports were published about genome-wide methylation in these neoplastic tissues, and an increasing number of small non-coding RNA are either up- or down-regulated in bladder cancer, indicating that impaired gene expression may also pass through these metabolic pathways. Taken together, these data reveal that bladder cancer is far to be considered a simple model of malignancy. In the present review, we summarize recent progress in the genome-wide analysis of bladder cancer, and analyse non-genetic, genetic and epigenetic factors causing extensive gene mis-regulation in malignant cells.

Characteristic patterns of microRNA expression in human bladder cancer

MicroRNAs (miRNAs) are small, non-coding RNAs that post-transcriptionally regulate gene expression. Their altered expression and functional activity have been observed in many human cancers. miRNAs represent promising diagnostic and prognostic molecular biomarkers, and also serve as novel therapeutic targets. We performed a systematic analysis of scientific reports that link differences in miRNA expression with the pathogenesis of bladder cancer (BC). This literature review is the first comprehensive database of miRNA molecules with biased expression profiles in BC. Among the 95 differentially expressed miRNAs that we identified from the literature, we classify 48 as up-regulated in BC, 35 as down-regulated, and 12 as contradictory (contradictory data were reported in one or more studies on the gene). In addition, we discuss the possible roles of differentially expressed miRNAs in the regulation of intracellular signaling pathways in BC.

Molecular basis of urinary bladder cancer

Bladder cancer is a relatively common and potentially life-threatening neoplasm. The diagnosis of urothelial carcinoma usually entails a lifelong surveillance to detect recurrent disease. In recent years, significant progress has been made in understanding the molecular mechanisms of carcinogenesis in urinary bladder. An early step in the process of carcinoma development is establishment of a premalignant abnormal urothelial patch that may give rise to various types of urothelial carcinoma and may provide a fertile ground for development of multifocal synchronous and metachronous tumors. Two distinct molecular pathways are involved. Low-grade papillary carcinoma is associated with mutation in the FGFR3 or in some cases mutations in RAS genes. High-grade in situ/muscle-invasive carcinoma on the other hand is characterized by alteration of p53 and pRB. Loss of function of these key genes, which play a crucial role in the control of cell cycle, leads to accumulation of additional mutations and deletions of genes resulting in an aggressive phenotype. It is hoped that a thorough understanding of the molecular basis of urothelial cancer will facilitate early diagnosis and will lead to development of new modalities for the management and treatment of these carcinomas.

Genitourinary schistosomiasis: life cycle and radiologic-pathologic findings

Genitourinary schistosomiasis is produced by Schistosoma haematobium, a species of fluke that is endemic to Africa and the Middle East, and causes substantial morbidity and mortality in those regions. It also may be seen elsewhere, as a result of travel or immigration. S haematobium, one of the five fluke species that account for most human cases of schistosomiasis, is the only species that infects the genitourinary system, where it may lead to a wide spectrum of clinical symptoms and signs. In the early stages, it primarily involves the bladder and ureters; later, the kidneys and genital organs are involved. It rarely infects the colon or lungs. A definitive diagnosis of genitourinary schistosomiasis is based on findings of parasite ova at microscopic urinalysis. Clinical manifestations and radiologic imaging features also may be suggestive of the disease, even at an early stage: Hematuria, dysuria, and hemospermia, early clinical signs of an established S haematobium infection, appear within 3 months after infection. At imaging, fine ureteral calcifications that appear as a line or parallel lines on abdominopelvic radiographs and as a circular pattern on axial images from computed tomography (CT) are considered pathognomonic of early-stage schistosomiasis. Ureteritis, pyelitis, and cystitis cystica, conditions that are characterized by air bubble-like filling defects representing ova deposited in the ureter, kidney, and bladder, respectively, may be seen at intravenous urography, intravenous ureteropyelography, and CT urography. Coarse calcification, fibrosis, and strictures are signs of chronic or late-stage schistosomiasis. Such changes may be especially severe in the bladder, creating a predisposition to squamous cell carcinoma. Genital involvement, which occurs more often in men than in women, predominantly affects the prostate and seminal vesicles.

The evaluation of retrospective pathological lesions on spirocercosis (Spirocerca lupi) in dogs

From 1998 to 2012, 42 dogs with spirocercosis referred to pathology Department of Veterinary Faculty, Tehran University. Frequency of spirocercosis was higher in October, November, December, January, February, March months. Averagely, the cases were 4.73 years old of age, so that 59.3 % of them were male. The major pathological findings were located in distal part of esophagus (57 %, n = 24), stomach (24 %, n = 10), and aorta (9.5 %, n = 4), respectively. In addition, 7 % (n = 3) were in esophagus and stomach, 2 % (n = 1) in esophagus and aorta, 42 % (n = 18) indicated pulmonary lesions with hyperemia, atelectasis, edema and pneumonia. In 35 % (n = 15) of cases were with hepatic lesions hyperemia and fatty change. However, 26 % (n = 11) cases demonstrated renal lesions with hyperemia, interstitial nephritis, and 24 % (n = 10) encompassed urinary bladder lesions with hyperemia and adhesive cystitis. Furthermore, sudden death occurred in 7 % (n = 3) as well as cachexia in 7 % (n = 3) cases. Some spirocercosis cases (12 %, n = 5) were accompanied by distemper disease, mixed mammary gland tumor (2 %, n = 1) and parasitic dermatitis due to demodicosis (9.5 %, n = 4). Presumably some of pathological findings were related or emerged by other sort of diseases such as distemper.

Urinary schistosomiasis: review

In this review, the clinical manifestations of urinary schistosomiasis are displayed from a pathogenetic perspective. According to the prevailing host’s immune response profile, urinary schistosomiasis may be broadly categorized into cell-mediated and immune-complex-mediated disorders. The former, usually due to Schistosoma haematobium infection, are attributed to the formation of granulomata along the entire urinary tract. As they heal with excessive fibrosis, they may lead to strictures, calcifications and urodynamic abnormalities. The main impact is lower urinary, the site of heaviest ovi-position. Secondary bacterial or viral infection is common, any may be incriminated in secondary stone formation of the development of bladder malignancy. Immune-complex mediated lesions are usually associated with hepatosplenic schistosomiasis due to Schistosoma mansoni infection. Circulating complexes composed of schistosomal gut antigens and different classes of immunoglobulins deposit in the kidneys leading to several patterns of glomerular pathology. The latter have been categorized under six classes based on the histological and immunofluorescence profile. These classes have been linked to respective clinical manifestations and depend on the stage of evolution of the host’s immune response, extent of associated hepatic fibrosis and co-infection with salmonella or hepatitis C. Secondary amyloidosis develops in 15% of such patients, representing a critical impairment of macrophage function. Conclusion: The wide clinicopathological spectrum of urinary schistosomiasis mirrors the evolution of the host’s immune response according to chronicity of infection, bacterial or viral co-infection and, in the case of glomerulonephritis, to the extent of hepatic co-morbidity.

p16 expression is not associated with human papillomavirus in urinary bladder squamous cell carcinoma

Squamous cell carcinoma of the urinary bladder is unusual and of unknown etiology. There is a well-established association between human papillomavirus (HPV) infection and the development of cervical and head/neck squamous cell carcinomas. However, the role of HPV in the pathogenesis of squamous cell carcinoma of the urinary bladder is uncertain. The purposes of this study were to investigate the possible role of HPV in the development of squamous cell carcinoma of the urinary bladder and to determine if p16 expression could serve as a surrogate marker for HPV in this malignancy. In all, 42 cases of squamous cell carcinoma of the urinary bladder and 27 cases of urothelial carcinoma with squamous differentiation were investigated. HPV infection was analyzed by both in situ hybridization at the DNA level and immunohistochemistry at the protein level. p16 protein expression was analyzed by immunohistochemistry. HPV DNA and protein were not detected in 42 cases of squamous cell carcinoma (0%, 0/42) or 27 cases of urothelial carcinoma with squamous differentiation (0%, 0/15). p16 expression was detected in 13 cases (31%, 13/42) of squamous cell carcinoma and 9 cases (33%, 9/27) of urothelial carcinoma with squamous differentiation. There was no correlation between p16 expression and the presence of HPV infection in squamous cell carcinoma of the bladder or urothelial carcinoma with squamous differentiation. Our data suggest that HPV does not play a role in the development of squamous cell carcinoma of the urinary bladder or urothelial carcinoma with squamous differentiation. p16 expression should not be used as a surrogate marker for evidence of HVP infection in either squamous cell carcinoma of the urinary bladder or urothelial carcinoma with squamous differentiation as neither HVP DNA nor protein is detectable in these neoplasms.

Study and implementation of urogenital schistosomiasis elimination in Zanzibar (Unguja and Pemba islands) using an integrated multidisciplinary approach

Background

Schistosomiasis is a parasitic infection that continues to be a major public health problem in many developing countries being responsible for an estimated burden of at least 1.4 million disability-adjusted life years (DALYs) in Africa alone. Importantly, morbidity due to schistosomiasis has been greatly reduced in some parts of the world, including Zanzibar. The Zanzibar government is now committed to eliminate urogenital schistosomiasis. Over the next 3–5 years, the whole at-risk population will be administered praziquantel (40 mg/kg) biannually. Additionally, snail control and behaviour change interventions will be implemented in selected communities and the outcomes and impact measured in a randomized intervention trial.

Methods/Design

In this 5-year research study, on both Unguja and Pemba islands, urogenital schistosomiasis will be assessed in 45 communities with urine filtration and reagent strips in 4,500 schoolchildren aged 9–12 years annually, and in 4,500 first-year schoolchildren and 2,250 adults in years 1 and 5. Additionally, from first-year schoolchildren, a finger-prick blood sample will be collected and examined for Schistosoma haematobium infection biomarkers. Changes in prevalence and infection intensity will be assessed annually. Among the 45 communities, 15 were randomized for biannual snail control with niclosamide, in concordance with preventive chemotherapy campaigns. The reduction of Bulinus globosus snail populations and S. haematobium-infected snails will be investigated. In 15 other communities, interventions triggering behaviour change have been designed and will be implemented in collaboration with the community. A change in knowledge, attitudes and practices will be assessed annually through focus group discussions and in-depth interviews with schoolchildren, teachers, parents and community leaders. In all 45 communities, changes in the health system, water and sanitation infrastructure will be annually tracked by standardized questionnaire-interviews with community leaders. Additional issues potentially impacting on study outcomes and all incurring costs will be recordedand monitored longitudinally.

Discussion

Elimination of schistosomiasis has become a priority on the agenda of the Zanzibar government and the international community. Our study will contribute to identifying what, in addition to preventive chemotherapy, needs to be done to prevent, control, and ultimately eliminate schistosomiasis, and to draw lessons for current and future schistosomiasis elimination programmes in Africa and elsewhere.

Trial registration

ISRCTN48837681

Integrated analysis of innate, Th1, Th2, Th17, and regulatory cytokines identifies changes in immune polarisation following treatment of human schistosomiasis

Background. Schistosomiasis elicits cross-regulatory immune responses, but it is unclear how antihelminthic treatment affects this balance. This study integrates data on 13 cytokines elicited by 3 schistosome to examine how praziquantel treatment alters immune polarization and whether post-treatment cytokine profiles influence reinfection status.

Methods. Venous blood from 72 Schistosoma haematobium–exposed participants was cultured with schistosome egg, adult worm, and cercaria antigens pre– and 6 weeks post–praziquantel treatment. Innate inflammatory (tumor necrosis factor α [TNF-α], interleukin(IL-)-6, IL-8), Th1 (interferon γ [IFN-γ], IL-2, IL-12p70), Th2 (IL-4, IL-5, IL-13), Th17 (IL-17A, IL-21, IL-23p19), and regulatory (IL-10) cytokines were quantified via enzyme-linked immunosorbent assay. Cytokine data was integrated using nonmetric multidimensional scaling and factor analysis.

Results. Egg-specific cytokine phenotypes became more proinflammatory post-treatment due to increased TNF-α, IL-6, IL-8, IFN-γ, IL-12p70, and IL-23 levels. Post-treatment cercariae-specific responses were also more proinflammatory reflecting elevated IL-8. In contrast, post-treatment adult worm-specific responses were less inflammatory, reflecting lower post-treatment IL-6. A combination of egg-induced IL-6, IL-12p70, IL-21, and IL-23 and adult worm-induced IL-5 and IL-21 post-treatment was associated with reduced reinfection risk 18 months later.

Conclusions. Praziquantel treatment markedly alters polarization of schistosome-specific cytokine responses, and these changes, particularly in response to egg-stage parasites, may promote resistance to reinfection.

Schistosomiasis may contribute to goblet cell carcinoid of the appendix

Abstract : To investigate whether schistosomiasis can contribute to appendiceal goblet cell carcinoid, appendix samples were obtained from 3 patients with combined appendiceal schistosomiasis and goblet cell carcinoid (CSG), 6 patients with goblet cell carcinoid only (GCC), 12 patients with appendiceal schistosomiasis only (ASO), and 12 cases with normal appendix (NA), all of similar gender ratio and age distributions. Hematoxylin and eosin-(H&E) stained sections were studied in 3 CSGs and 12 ASOs to diagnose schistosomiasis by detecting schistosome eggs. H&E and alcian blue/PAS-stained sections and immunohistochemistry of CgA and CEA were employed to establish the diagnosis of GCC in the 3 CSGs and 6 GCCs. Then, to determine whether schistosomiasis can contribute to GCC, immunostaining patterns of CgA and Ki67 in mucosal crypt epithelia were investigated and compared among all 33 cases. Our results revealed typical histological and immunohistochemical phenotypes of GCC in the 3 CSGs and 6 GCCs and schistosome egg deposits in 3 CSGs and 12 ASOs. We found that the expression levels of both CgA and Ki67 in mucosal crypt epithelia were significantly higher in CSG than in GCC (P < 0.05  =  0.013 and P  =  0.004, respectively). Moreover, high expression levels of both CgA and Ki67 in mucosal crypt epithelia favor ASO as compared to NA (P < 0.001  =  3.4 × 10(-6) and 3.1 × 10(-5), respectively). Our findings suggest that appendiceal schistosomiasis was associated with increased proliferation and neuroendocrine differentiation of mucosal pluripotent crypt cells and that it may contribute to GCC, which is documented to originate from mucosal pluripotent crypt cells in mucosal crypt epithelia.

Evolutionary medicine: its scope, interest and potential

This review is aimed at readers seeking an introductory overview, teaching courses and interested in visionary ideas. It first describes the range of topics covered by evolutionary medicine, which include human genetic variation, mismatches to modernity, reproductive medicine, degenerative disease, host-pathogen interactions and insights from comparisons with other species. It then discusses priorities for translational research, basic research and health management. Its conclusions are that evolutionary thinking should not displace other approaches to medical science, such as molecular medicine and cell and developmental biology, but that evolutionary insights can combine with and complement established approaches to reduce suffering and save lives. Because we are on the cusp of so much new research and innovative insights, it is hard to estimate how much impact evolutionary thinking will have on medicine, but it is already clear that its potential is enormous.

N-Acetyltransferase 1 (NAT1) Genotype: A Risk Factor for Urinary Bladder Cancer in a Lebanese Population

In Lebanon, bladder cancer is the second most incident cancer among men. This study investigates a possible association between N-acetyltransferase 1 (NAT1) genotype, a drug-metabolizing enzyme coding gene, and bladder cancer in Lebanese men. A case-control study (54 cases and 105 hospital-based controls) was conducted in two major hospitals in Beirut. Cases were randomly selected from patients diagnosed in the period of 2002–2008. Controls were conveniently identified and selected from the same settings. Data was collected using interview questionnaire and blood analysis. NAT1 genotypes were determined by PCR-RFLP. Statistical analysis revolved around univariate, bivariate, and multivariate logistic regression models, along with checks for effect modification. Results showed NAT1^∗14A allele, smoking, occupational exposure to combustion fumes, and prostate-related symptoms, to be risk factors for bladder cancer. The odds of carrying at least one NAT1^∗14A allele are 7 times higher in cases compared to controls (OR = 7.86, 95% CI: 1.53–40.39). A gene-environment interaction was identified for NAT1^∗14A allele with occupational exposure to combustion fumes. Among carriers of NAT1^∗14A allele, the odds of bladder cancer dropped to 2.03 from 3.72. Our study suggests NAT1^∗14A allele as a possible biomarker for bladder cancer. Further research is recommended to confirm this association.

The Importance of Definitive Diagnosis in Chronic Schistosomiasis, with Reference to Schistosoma haematobium

Schistosomes are long-lived parasites, hence schistosomiasis is a chronic disease with severe long-term implications. However, definitive diagnosis of active infection has been difficult because demonstration of infection has depended on detecting parasite eggs in urine and/or stool. In the case of Schistosoma haematobium which parasitizes the urinogenital system, this method has low sensitivity in adults. Detection of parasite-specific DNA in urine has been demonstrated and this has similar specificity but improved sensitivity. The implications of this new procedure and the impact on diagnosis are discussed.

Circumcision and the risk of prostate cancer

BACKGROUND

Several lines of evidence support a role for infectious agents in the development of prostate cancer (PCa). In particular, sexually transmitted infections (STIs) have been implicated in PCa etiology, and studies have found that the risk of acquiring a STI can be reduced with circumcision. Therefore, circumcision may reduce PCa risk.

METHODS

Participant data collected as part of 2 population-based case-control studies of PCa were analyzed. Self-reported circumcision status, age at circumcision, and age at first sexual intercourse were recorded along with a history of STIs or prostatitis. Multivariate logistic regression was used to estimate the relative risk of PCa by circumcision status.

RESULTS

Data from 1754 cases and 1645 controls were available. Circumcision before first sexual intercourse was associated with a 15% reduction in risk of PCa compared to that of uncircumcised men (95% confidence interval [CI], 0.73-0.99). This risk reduction was observed for cases with both less aggressive (odds ratio, 0.88; 95% CI, 0.74-1.04) and more aggressive (odds ratio, 0.82; 95% CI, 0.66-1.00) PCa features.

CONCLUSIONS

Circumcision before first sexual intercourse is associated with a reduction in the relative risk of PCa in this study population. These findings are consistent with research supporting the infectious/inflammation pathway in prostate carcinogenesis.

Parasites and malignancies, a review, with emphasis on digestive cancer induced by Cryptosporidium parvum (Alveolata: Apicomplexa)

The International Agency for Research on Cancer (IARC) identifies ten infectious agents (viruses, bacteria, parasites) able to induce cancer disease in humans. Among parasites, a carcinogenic role is currently recognized to the digenetic trematodes Schistosoma haematobium, leading to bladder cancer, and to Clonorchis sinensis or Opisthorchis viverrini, which cause cholangiocarcinoma. Furthermore, several reports suspected the potential association of other parasitic infections (due to Protozoan or Metazoan parasites) with the development of neoplastic changes in the host tissues. The present work shortly reviewed available data on the involvement of parasites in neoplastic processes in humans or animals, and especially focused on the carcinogenic power of Cryptosporidium parvum infection. On the whole, infection seems to play a crucial role in the etiology of cancer.

Cancer burden in Africa and opportunities for prevention

Cancer is an emerging public health problem in Africa. About 715,000 new cancer cases and 542,000 cancer deaths occurred in 2008 on the continent, with these numbers expected to double in the next 20 years simply because of the aging and growth of the population. Furthermore, cancers such as lung, female breast, and prostate cancers are diagnosed at much higher frequencies than in the past because of changes in lifestyle factors and detection practices associated with urbanization and economic development. Breast cancer in women and prostate cancer in men have now become the most commonly diagnosed cancers in many Sub-Saharan African countries, replacing cervical and liver cancers. In most African countries, cancer control programs and the provision of early detection and treatment services are limited despite this increasing burden. This paper reviews the current patterns of cancer in Africa and the opportunities for reducing the burden through the application of resource level interventions, including implementation of vaccinations for liver and cervical cancers, tobacco control policies for smoking-related cancers, and low-tech early detection methods for cervical cancer, as well as pain relief at the palliative stage of cancer.

Dispersive micro-solid phase extraction combined with gas chromatography-chemical ionization mass spectrometry for the determination of N-nitrosamines in swimming pool water samples

A simple sample pretreatment technique, dispersive micro-solid phase extraction, was applied for the extraction of N-nitrosodimethylamine (NDMA) and other four N-nitrosamines (NAs) from samples of swimming pool water. The parameters affecting the extraction efficiency were systematically investigated. The best extraction conditions involved immersing 75 mg of carbon molecular sieve, Carboxen™ 1003 (as an adsorbent), in a 50-mL water sample (pH 7.0) containing 5% sodium chloride in a sample tube. After 20 min of extraction by vigorous shaking, the adsorbent was collected on a filter and the NAs desorbed by treatment with 150 μL of dichloromethane. A 10-μL aliquot was then directly determined by large-volume injection gas chromatography with chemical ionization mass spectrometry using the selected ion storage mode. The limits of quantitation were <0.9 ng/L. The precision for these analytes, as indicated by relative standard deviations, were <8% for both intra- and inter-day analyses. Accuracy, expressed as the mean extraction recovery, was between 62% and 109%. A preliminary analysis of swimming pool water samples revealed that NDMA was present in the highest concentration, in the range from n.d. to 100 ng/L.

Validation of a new test for Schistosoma haematobium based on detection of Dra1 DNA fragments in urine: evaluation through latent class analysis

Background

Diagnosis of urogenital schistosomiasis in chronically infected adults is challenging but important, especially because long term infection of the bladder and urinary tract can have dire consequences. We evaluated three tests for viable infection: detection of parasite specific DNA Dra1 fragments, haematuria and presence of parasite eggs for sensitivity (Se) and specificity (Sp).

Methods

Over 400 urine specimens collected from adult volunteers in an endemic area in Western Nigeria were assessed for haematuria then filtered in the field, the filter papers dried and later examined for eggs and DNA. The results were stratified according to sex and age and subjected to Latent Class analysis.

Conclusions

Presence of Dra1 in males (Se = 100%; Sp = 100%) exceeded haematuria (Se = 87.6%: Sp = 34.7%) and detection of eggs (Se = 70.1%; Sp = 100%). In females presence of Dra1 was Se = 100%: Sp = 100%, exceeding haematuria (Se = 86.7%: Sp = 77.0%) and eggs (Se = 70.1%; Sp = 100%). Dra1 became undetectable 2 weeks after praziquantel treatment. We conclude detection of Dra1 fragment is a definitive test for the presence of Schistosoma haematobium infection.

The definitive test for schistosomiasis has been to detect parasite eggs in excreta. This is effective in children but as people age, it is difficult to find the eggs in spite of suspicion of infection. It also implies that adults have thrown off the infection, and therefore the infection is mainly one of children. However this is not the case as adults with chronic infections can develop severe bladder infection that can progress to bladder cancer. In clinical situations a sensitive test for urogenital schistosomiasis is important. We have recently shown that it is possible to detect schistosome species-specific DNA in urine, even in the absence of eggs in excreta. Here we use latent class analysis to compare sensitivity and specificity of three test procedures, haematuria, eggs in urine and specific DNA in urine in the absence of a gold standard. We show that the latter test is extremely promising for the diagnosis of urogenital schistosomiasis and should also be useful in field studies as it will be able to reveal infections in people frequently presumed to be uninfected. This new test indicated the presence of schistosomes in 10.7% of adults who did not pass eggs in urine specimens.

Urinary bladder cancer risk factors in Egypt: a multicenter case-control study

BACKGROUND

We investigated associations between tobacco exposure, history of schistosomiasis, and bladder cancer risk in Egypt.

METHODS

We analyzed data from a case-control study (1,886 newly diagnosed and histologically confirmed cases and 2,716 age-, gender-, and residence-matched, population-based controls). Using logistic regression, we estimated the covariate-adjusted ORs and 95% confidence interval (CI) of the associations.

RESULTS

Among men, cigarette smoking was associated with an increased risk of urothelial carcinoma (OR = 1.8; 95% CI, 1.4-2.2) but not squamous cell carcinoma (SCC); smoking both water pipes and cigarettes was associated with an even greater risk for urothelial carcinoma (OR = 2.9; 95% CI, 2.1-3.9) and a statistically significant risk for SCC (OR = 1.8; 95% CI, 1.2-2.6). Among nonsmoking men and women, environmental tobacco smoke exposure was associated with an increased risk of urothelial carcinoma. History of schistosomiasis was associated with increased risk of both urothelial carcinoma (OR = 1.9; 95% CI, 1.2-2.9) and SCC (OR = 1.9; 95% CI, 1.2-3.0) in women and to a lesser extent (OR = 1.4; 95% CI, 1.2-1.7 and OR = 1.4; 95% CI, 1.1-1.7, for urothelial carcinoma and SCC, respectively) in men.

CONCLUSIONS

The results suggest that schistosomiasis and tobacco smoking increase the risk of both SCC and urothelial carcinoma.

IMPACT

This study provides new evidence for associations between bladder cancer subtypes and schistosomiasis and suggests that smoking both cigarettes and water pipes increases the risk for SCC and urothelial carcinoma in Egyptian men.

Diagnosis of Schistosoma haematobium by detection of specific DNA fragments from filtered urine samples

Definitive diagnosis of Schistosoma haematobium infection in adult patients is a clinically important challenge. Chronically infected adults pass few eggs in the urine, which are often missed when current diagnostic methods are used. In the work presented here, we report on an alternative diagnostic method based on presence of the S. haematobium-specific Dra 1, 121 bp repeat fragment in human urine. A novel method of collecting the urine specimens in the field and filtering them through heavy Whatman No. 3 paper was introduced. After drying, the samples remained viable for several months at room temperature. To test the potential use of this method, 89 urine specimens from school children in Kollo District, Niger, were examined. In all, 52 of 89 (58.4%) were positive for hematuria, 4 of 89 (49.4%) were positive for eggs, and 51 of 89 (57.3%) showed parasite-specific DNA. These were compared with 60 filtered urine specimens obtained from random samples of adults from two study sites in Nigeria, one endemic and one non-endemic for S. haematobium. In the 30 patients from the endemic site, all 10 samples with detectable eggs and 7 of the 20 egg-negative samples were DNA positive. It was concluded that the urine filter paper method was sufficiently sensitive to detect low and cryptic infections, that DNA detection was more sensitive than egg detection, and that the filtration method facilitated specimen collection and transport from the field.

Update on the management of non-muscle invasive bladder cancer

Non-muscle invasive bladder cancer (NMIBC) is a heterogeneous population of tumours accounting for 80% of bladder cancers. Over the years, the management of this disease has been changing with improvements in results and outcomes. In this review, we focus on the latest updates on the management of NMIBC.

Reactive species and DNA damage in chronic inflammation: reconciling chemical mechanisms and biological fates

Chronic inflammation has long been recognized as a risk factor for many human cancers. One mechanistic link between inflammation and cancer involves the generation of nitric oxide, superoxide and other reactive oxygen and nitrogen species by macrophages and neutrophils that infiltrate sites of inflammation. Although pathologically high levels of these reactive species cause damage to biological molecules, including DNA, nitric oxide at lower levels plays important physiological roles in cell signaling and apoptosis. This raises the question of inflammation-induced imbalances in physiological and pathological pathways mediated by chemical mediators of inflammation. At pathological levels, the damage sustained by nucleic acids represents the full spectrum of chemistries and likely plays an important role in carcinogenesis. This suggests that DNA damage products could serve as biomarkers of inflammation and oxidative stress in clinically accessible compartments such as blood and urine. However, recent studies of the biotransformation of DNA damage products before excretion point to a weakness in our understanding of the biological fates of the DNA lesions and thus to a limitation in the use of DNA lesions as biomarkers. This review will address these and other issues surrounding inflammation-mediated DNA damage on the road to cancer.

Contemporary management of low-risk bladder cancer

Bladder cancer comprises a heterogeneous group of tumors, the majority of which are non-muscle-invasive bladder cancer (NMIBC) at initial presentation. Low-risk bladder cancer--defined as pTa low-grade papillary tumors--is the type of NMIBC with the most favorable oncologic outcome. Although the risk of progression is less than 1% in 5 years, almost 15% will recur after 1 year, and 32% after 5 years. A complete transurethral resection, followed by an immediate single postoperative instillation of chemotherapy will reduce the risk of recurrence for the first 2 years. Follow-up cystoscopy is required to detect recurrence; in the vast majority of cases the recurrent tumor is of the same stage and grade as the primary tumor. The first follow-up visit, 3 months after surgery, is the most important in predicting risk of recurrence for the future. Recent developments in profiling urine and cancer tissue make it possible to better predict risk of progression and recurrence. In the future this profiling will play an important role in the timing and the choice of treatment, as well as guiding follow-up procedures.

Origins of injection-site sarcomas in cats: the possible role of chronic inflammation-a review

The etiology of feline injection-site sarcomas remains obscure. Sarcomas and other tumors are known to be associated with viral infections in humans and other animals, including cats. However, the available evidence suggests that this is not the case with feline injection-site sarcomas. These tumors have more in common with sarcomas noted in experimental studies with laboratory animals where foreign materials such as glass, plastics, and metal are the causal agent. Tumors arising with these agents are associated with chronic inflammation at the injection or implantation sites. Similar tumors have been observed, albeit infrequently, at microchip implantation sites, and these also are associated with chronic inflammation. It is suggested that injection-site sarcomas in cats may arise at the administration site as a result of chronic inflammation, possibly provoked by adjuvant materials, with subsequent DNA damage, cellular transformation, and clonal expansion. However, more fundamental research is required to elucidate the mechanisms involved.

Levels of certain tumor markers as differential factors between bilharzial and non-biharzial bladder cancer among Egyptian patients

BACKGROUND/OBJECTIVE

Bladder cancer is the commonest type of malignant tumors as a result of schistosomaisis which is a major healthy problem in many subtropical developing countries. The aim of this study is to comparatively elucidate the underlying biochemical tumor markers in schistosomal bladder cancer versus non-schistosomal bladder cancer when compared to normal healthy ones.

METHODS

This work was performed on tissue specimens from total 25 patients and serum samples from total 30 patients versus ten healthy individuals served as control. The investigated parameters in serum are: xanthine oxidase (XO), fructosamine, lactate dehydrogense (LDH), aspartate aminotransferase (AST), alanine aminotransferase (ALT), total proteins, essential and non- essential amino acids profile, hydroxyproline, total immunoglobulin E (IgE) and tumor necrosis factor alpha (TNF-α). In addition, the current investigation also extended to study some markers in tumor bladder tissues including, pyruvate kinase enzyme (PK), lactate dehydrogenase (LDH), aspartate aminotransferase (AST) and alanine aminotransferase (ALT).

RESULTS

Results showed that biharzial bladder cancer patients recored more significant elevation in serum XO, fructosamine, LDH, AST, ALT, hydroxyproline, IgE and TNF-α than in bladder cancer patients when compared to control ones. While, in tissues there were significant increase in PK, LDH, AST & ALT activities of schistosomal bladder cancer than in bladder cancer as compared to control healthy patients.

CONCLUSIONS

It could be concluded that, bilharzial and non-bilharzial bladder cancer showed distinct biochemical profile of tumor development and progression which can be taken into consideration in diagnosis of bladder cancer.

Determination of nitrosamines in water by gas chromatography/chemical ionization/selective ion trapping mass spectrometry

A gas chromatography/mass spectrometry (GC/MS) method for determination of nine N-nitrosamines (NAs) in water is described. Two ionization modes, electron impact (EI) and chemical ionization (CI) with methanol, as well as different ion analysis techniques, i.e. full scan, selected ion storage (SIS) and tandem mass spectrometry (MS/MS) were tested. Chemical ionization followed by SIS resulted the mass spectrometric method of choice, with detection limits in the range of 1-2ng/L. Solid Phase Extraction (SPE) with coconut charcoal cartridges was applied to extract NAs from real samples, according EPA Method 521. Drinking water samples were collected from seven surface- and two groundwater treatment plants. Three surface water treatment plants were sampled before and after addition of O(3)/ClO(2) to observe the effect of disinfection on NAs' formation. N-nitrosodiethylamine (NDEA), n-nitrosodipropylamine (NDPA), n-nitrosomorpholine (NMOR) and n-nitrosodibutylamine (NDBA) were found up to concentrations exceeding three times the risk level of 10ng/L set by the California Department of Public Health. Because dermal adsorption has been recently indicated as a new contamination route of exposure to NAs for people who practice swimming activity, water samples from five swimming pools in the Bologna (Italy) area were collected. N-nitrosopyrrolidine (NPYR) was detected in all samples at concentrations larger than 50ng/L, likely as a disinfection by-product from the amino acid precursor proline, a main constituent of skin collagen.

Mechanisms linking pathogens-associated inflammation and cancer

It has been estimated that chronic infections with viruses, bacteria and parasites are the causative agents of 8-17% of global cancers burden. Carcinogenesis associated with infections is a complex process, often mediated by chronic inflammatory conditions and accumulating evidence indicate that a smouldering inflammation is a component of the tumor microenvironment and represents the 7th hallmark of cancer. Selected infectious agents promote a cascade of events culminating in chronic inflammatory responses, thus predisposing target tissues to increased cancer susceptibility. A causal link also exists between an inflammatory microenvironment, consisting of inflammatory cells and mediators, and tumor progression. Tumor-Associated Macrophages (TAM) represent the major inflammatory population present in tumors, orchestrating various aspects of cancer, including: diversion and skewing of adaptive responses; cell growth; angiogenesis; matrix deposition and remodelling; construction of a metastatic niche and actual metastasis; response to hormones and chemotherapeutic agents. Recent studies on human and murine tumors indicate that TAM show a remarkable degree of plasticity and functional heterogeneity, during tumour development. In established tumors, TAM acquire an M2 polarized phenotype are engaged in immunosuppression and the promotion of tumor angiogenesis and metastasis. Being a first line of the innate defence mechanisms, macrophages are also equipped with pathogen-recognition receptors, to sense the presence of danger signals, including onco-pathogens. Here we discuss the evidence suggesting a causal relationship between selected infectious agents and the pro-tumoral reprogramming of inflammatory cells, as well as its significance in tumor development. Finally, we discuss the implications of this phenomenon for both cancer prevention and therapy.

Fibroblast growth factor-10 signals development of von Brunn's nests in the exstrophic bladder

von Brunn's nests have long been recognized as precursors of benign lesions of the urinary bladder mucosa. We report here that von Brunn's nests are especially prevalent in the exstrophic bladder, a birth defect that predisposes the patient to formation of bladder cancer. Cells of von Brunn's nest were found to coalesce into a stratified, polarized epithelium which surrounds itself with a capsule-like structure rich in types I, III, and IV collagen. Histocytochemical analysis and keratin profiling demonstrated that nested cells exhibited a phenotype similar, but not identical, to that of urothelial cells of transitional epithelium. Immunostaining and in situ hybridization analysis of exstrophic tissue demonstrated that the FGF-10 receptor is synthesized and retained by cells of von Brunn's nest. In contrast, FGF-10 is synthesized and secreted by mesenchymal fibroblasts via a paracrine pathway that targets basal epithelial cells of von Brunn's nests. Small clusters of 10pRp cells, positive for both FGF-10 and its receptor, were observed both proximal to and inside blood vessels in the lamina propria. The collective evidence points to a mechanism where von Brunn's nests develop under the control of the FGF-10 signal transduction system and suggests that 10pRp cells may be the original source of nested cells.

Geographic patterns of cancer in the population-based registry of Egypt: Possible links to environmental exposures

BACKGROUND

We investigated the variation in cancer incidence in Gharbiah, Egypt to explore geographic differences in relation to demographic and environmental exposures.

METHODS

Using data from the only population-based cancer registry of Gharbiah, we studied the 10 most common cancers in men and women over 4 years (1999-2002). Census data provided denominators and urban-rural definitions. Crude and adjusted incidence rates (IRs), incidence rate ratios (IRRs) and 95% confidence intervals (CIs) were estimated using Poisson regression.

RESULTS

Incidence of all common cancers was higher among men than women and urban incidence was higher than rural incidence for all cancer sites. Among men and women urban-rural incidence difference was highest for prostate cancer (IRR=4.85, 95% CI=3.76, 6.26) and uterus (IRR=6.05, 95% CI=4.17, 8.78), respectively. Among men and women, El-Santa district had the highest urban-rural difference within districts for laryngeal cancer (IRR=29.45, 95% CI=10.63, 81.61) and uterine cancer (IRR=15.98, 95% CI=2.69, 95.10), respectively. El-Santa also showed the highest urban incidence among all eight districts for most cancer sites.

CONCLUSIONS

Geographic differences of cancers in Gharbiah need in-depth investigation with respect to specific environmental factors that explain the geographic cancer in this region.

Expression of O-Alkylguanine-DNA Alkyltransferase in Normal and Malignant Bladder Tissue of Egyptian Patients

Bladder tumour tissues and corresponding uninvolved mucosa (normal tissue) of Egyptian bladder cancer patients were assessed for O⁶-alkylguanine-DNA-alkyltransferase (MGMT) activity by functional assay of tissue extracts (36 paired samples), and distribution by immunofluorescence (IF) microscopy of fixed material (24 paired samples). MGMT varied widely from 42–253 fmoles/mg protein and from 3.2–40 fmoles/μg DNA in normal and 58–468 fmoles/mg protein and 2.5–49.5 fmoles/mg protein, in the tumour tissues; only one tumour had undetectable activity. Pairwise comparison of MGMT activity in tumour and adjacent normal tissue showed no significant difference based on DNA content but was 1.75-fold higher in tumour (P < .01) based on protein. There was no effect of gender or bilharzia infection status. IF showed that in tumours, both the mean percentage of positive nuclei (57.3 ± 20.3%) and mean integrated IF (5.47 ± 3.66) were significantly higher than those in uninvolved tissues (42.8 ± 13.5% P = .04) and (1.89 ± 1.42; P < .01), respectively. These observations suggest that, overall, MGMT levels are increased during human bladder carcinogenesis and that MGMT downregulation is not a common feature of bladder cancers. Based on this, bladder cancers would be expected to be relatively resistant to chemotherapy which involved O⁶-guanine alkylating antitumour agents.

Estrogen exposure and bladder cancer risk in Egyptian women

OBJECTIVE

To examine associations between reproductive history and urinary bladder cancer in Egyptian women.

METHODS

We used questionnaire data from an ongoing, multicenter case-control study in Egypt. Controls were matched on age and residence area. This analysis focused on female cases with confirmed urothelial (UC) and squamous cell (SCC) carcinoma of the bladder.

RESULTS

We recruited 779 women (540 controls, 239 cases; >98.0% nonsmokers). Younger age at menopause (<45 y) and older age at first pregnancy (>18 y) were factors significantly associated with increased risk of bladder cancer, even after adjusting for schistosomiasis history and other covariates in the multivariable logistic model; adjusted odds ratio and 95% confidence intervals were 1.98 (1.41, 2.77) and 6.26 (3.46, 11.34), respectively. On the other hand, multiple pregnancies or use of oral contraceptives were associated with decreased odds of having bladder cancer. Similar associations were observed with UC and SCC when analyzed separately; however, the magnitude of association with SCC was lower than with UC.

CONCLUSION

Our data suggest that early estrogen exposure, or the relative lack of it, plays a role in urinary bladder carcinoma development among Egyptian women.

Challenges in developing DNA and RNA biomarkers of inflammation

Inflammation is now a proven cause of human diseases such as cancer and cardiovascular disease. One potential link between inflammation and disease involves secretion of reactive chemical species by immune cells, with chronic damage to host epithelial cells leading to disease. This suggests pathophysiologically that DNA and RNA damage products are candidate biomarkers of inflammation, both for mechanistic understanding of the process and for risk assessment. Of the current approaches to quantifying DNA damage products, mass spectrometry-based methods provide the most rigorous quantification needed for biomarker development, while antibody-based approaches provide the most practical way to implement biomarkers in a clinical setting. Nonetheless, all approaches are biased by adventitious formation of DNA and RNA damage products during sample processing. Recent studies of tissue-derived DNA biomarkers in mouse models of inflammation reveal significant changes only in DNA adducts derived from lipid peroxidation. These and other observations raise the question of the most appropriate sampling compartment for DNA biomarker studies and highlight the emerging role of lipid damage in inflammation.

99th Dahlem conference on infection, inflammation and chronic inflammatory disorders: symbionts and immunopathology in chronic diseases: insights from evolution

Immunological aetiologies of disease are not generally well understood, but have been attributed to intrinsic immunological imbalances, infectious triggers or persistent infections. Evolutionary considerations lead to the formulation of three feasible categories of immunopathology for common diseases. One category of hypotheses presumes that the immune system is exposed to environmental conditions to which the individual is not well adapted. One hypothesis within this category, often referred to as the hygiene hypothesis, proposes that new more hygienic environmental conditions have generated compositions of symbionts that differ from those to which humans have been adapted. A second category of hypotheses proposes that infectious agents act as triggers of immunopathology by shifting the immune system into a self-destructive state. A third category proposes that infectious agents keep the immune in a self-destructive state by causing persistent infections. To evaluate disease causation rigorously and to determine the appropriate interventions, these three categories of causation need to considered for every disease that involves immunopathology. Assessment of the progress in understanding oncogenesis and other chronic diseases emphasizes the value of such integrated assessments.

Genotoxicity of water concentrates from recreational pools after various disinfection methods

Swimming and hot tub bathing are popular exercises and diversions. Disinfection of recreational pools is essential to prevent outbreaks of infectious disease. Recent research demonstrated an association between the application of disinfectants to recreational pools and adverse health outcomes. These pool waters represent extreme cases of disinfection that differ from disinfecting drinking waters. Pool waters are continuously exposed to disinfectants over average residence times extending to months. Disinfection byproduct (DBP) precursors include natural humic substances plus inputs from bathers through urine, sweat, hair, skin, and consumer products including cosmetics and sunscreens. This study presents a systematic mammalian cell genotoxicity analysis to evaluate different recreational waters derived from a common tap water source. The data demonstrated that all disinfected recreational pool water samples induced more genomic DNA damage than the source tap water. The type of disinfectant and illumination conditions altered the genotoxicity of the water. Accordingly, care should be taken in the disinfectant employed to treat recreational pool waters. The genotoxicity data suggest that brominating agents should be avoided. Combining chlorine with UV may be beneficial as compared to chlorination alone. During the recycling of pool water the organic carbon could be removed prior to disinfection. Behavior modification by swimmers may be critical in reducing the genotoxicity of pool water. Actions such as showering before entering the water and informing patrons about the potential harm from urinating in a pool could reduce the precursors of toxic DBPs.

Inflammation and cancer: interweaving microRNA, free radical, cytokine and p53 pathways

Chronic inflammation and infection are major causes of cancer. There are continued improvements to our understanding of the molecular connections between inflammation and cancer. Key mediators of inflammation-induced cancer include nuclear factor kappa B, reactive oxygen and nitrogen species, inflammatory cytokines, prostaglandins and specific microRNAs. The collective activity of these mediators is largely responsible for either a pro-tumorigenic or anti-tumorigenic inflammatory response through changes in cell proliferation, cell death, cellular senescence, DNA mutation rates, DNA methylation and angiogenesis. As our understanding grows, inflammatory mediators will provide opportunities to develop novel diagnostic and therapeutic strategies. In this review, we provide a general overview of the connection between inflammation, microRNAs and cancer and highlight how our improved understanding of these connections may provide novel preventive, diagnostic and therapeutic strategies to reduce the health burden of cancer.

Potential role of chitinase 3-like-1 in inflammation-associated carcinogenic changes of epithelial cells

The family of mammalian chitinases includes members both with and without glycohydrolase enzymatic activity against chitin, a polymer of N-acetylglucosamine. Chitin is the structural component of fungi, crustaceans, insects and parasitic nematodes, but is completely absent in mammals. Exposure to antigens containing chitin- or chitin-like structures sometimes induces strong T helper type-I responses in mammals, which may be associated with the induction of mammalian chitinases. Chitinase 3-like-1 (CHI3L1), a member of the mammalian chitinase family, is induced specifically during the course of inflammation in such disorders as inflammatory bowel disease, hepatitis and asthma. In addition, CHI3L1 is expressed and secreted by several types of solid tumors including glioblastoma, colon cancer, breast cancer and malignant melanoma. Although the exact function of CHI3L1 in inflammation and cancer is still largely unknown, CHI3L1 plays a pivotal role in exacerbating the inflammatory processes and in promoting angiogenesis and remodeling of the extracellular matrix. CHI3L1 may be highly involved in the chronic engagement of inflammation which potentiates development of epithelial tumorigenesis presumably by activating the mitogen-activated protein kinase and the protein kinase B signaling pathways. Anti-CHI3L1 antibodies or pan-chitinase inhibitors may have the potential to suppress CHI3L1-mediated chronic inflammation and the subsequent carcinogenic change in epithelial cells.

Incidence analyses of bladder cancer in the Nile delta region of Egypt

Bladder cancer is the most common malignancy among Egyptian males and previously has been attributed to Schistosoma infection, a major risk factor for squamous cell carcinoma (SCC). Recently, transitional cell carcinoma (TCC) incidence has been increasing while SCC has declined. To investigate this shift, we analyzed the geographical patterns of all bladder cancers cases recorded in Egypt's Gharbiah Population-Based Cancer Registry from 1999 through 2002. Data on tumor grade, stage, and morphology, as well as smoking, community of residence, age and sex, were collected on 1209 bladder cancer cases. Age-adjusted incidence rates were calculated for males, females, and the total population for the eight administrative Districts and 316 communities in Gharbiah. Incidence Rate Ratios (IRR) and 95% confidence intervals (CI) were computed using Poisson Regression. The male age-adjusted incidence rate (IR) in Gharbiah Province was 13.65/100,000 person years (PY). The District of Kotour had the highest age-adjusted IR 28.96/100,000 among males. The District of Kotour also had the highest IRR among all Districts, IRR=2.15 95% CI (1.72, 2.70). Kotour's capital city had the highest bladder cancer incidence among the 316 communities (IR=73.11/100,000 PY). Future studies on sources and types of environmental pollution and exposures in relation to the spatial patterns of bladder cancer, particularly in Kotour District, may improve our understating of risk factors for bladder cancer in the region.

Endogenous damage-associated molecular pattern molecules at the crossroads of inflammation and cancer

Inflammatory mediators play important roles in the development and progression of cancer. Cellular stress, damage, inflammation, and necrotic cell death cause release of endogenous damage-associated molecular pattern (DAMP) molecules or alarmins, which alert the host of danger by triggering immune responses and activating repair mechanisms through their interaction with pattern recognition receptors. Recent studies show that abnormal persistence of these molecules in chronic inflammation and in tumor microenvironments underlies carcinogenesis and tumor progression, indicating that DAMP molecules and their receptors could provide novel targets for therapy. This review focuses on the role of DAMP molecules high-mobility group box 1 and S100 proteins in inflammation, tumor growth, and early metastatic events.

Molecular pathogenesis and diagnostics of bladder cancer

Despite elaborate characterization of the risk factors, bladder cancer is still a major epidemiological problem whose incidence continues to rise each year. Urothelial carcinoma is now recognized as a disease of alterations in several cellular processes. The more prevalent, less aggressive, recurrent, noninvasive tumors are characterized by constitutive activation of the Ras-MAPK pathway. The less common but more aggressive invasive tumors, which have a higher mortality rate, are characterized by alterations in the p53 and retinoblastoma pathways. Several diagnostic tests have attempted to identify these molecular alterations in tumor cells exfoliated in the urine, whereas prognostic tests have tried to identify aberrations so as to predict tumor behavior and identify therapeutic targets. The future of bladder cancer patient management will rely on the use of molecular tests to reliably diagnose the presence of disease, predict individual tumor behavior, and suggest potential targeted therapeutics.

Chronic Mycobacterium marinum infection acts as a tumor promoter in Japanese Medaka (Oryzias latipes)

An accumulating body of research indicates there is an increased cancer risk associated with chronic infections. The genus Mycobacterium contains a number of species, including M. tuberculosis, which mount chronic infections and have been implicated in higher cancer risk. Several non-tuberculosis mycobacterial species, including M. marinum, are known to cause chronic infections in fish and like human tuberculosis, often go undetected. The elevated carcinogenic potential for fish colonies infected with Mycobacterium spp. could have far reaching implications because fish models are widely used to study human diseases. Japanese medaka (Oryzias latipes) is an established laboratory fish model for toxicology, mutagenesis, and carcinogenesis; and produces a chronic tuberculosis-like disease when infected by M. marinum. We examined the role that chronic mycobacterial infections play in cancer risk for medaka. Experimental M. marinum infections of medaka alone did not increase the mutational loads or proliferative lesion incidence in all tissues examined. However, we showed that chronic M. marinum infections increased hepatocellular proliferative lesions in fish also exposed to low doses of the mutagen benzo[a]pyrene. These results indicate that chronic mycobacterial infections of medaka are acting as tumor promoters and thereby suggest increased human risks for cancer promotion in human populations burdened with chronic tuberculosis infections.

Tumor markers of bladder cancer: the schistosomal bladder tumors versus non-schistosomal bladder tumors

Background

The aim of this study is to comparatively elucidate the underlying molecular pathways and clinicopathological criteria in schistosomal bladder tumor (SBT) versus non-schistosomal bladder tumor (NSBT).

Methods

This study explored the role of p53, p16, bcl-2, ki-67, c-myc, Rb and EGFR, by using Immunohistochemistry assay, in 45 SBT and 39 NSBT patients in comparison with 16 schistosomal chronic cystitis (SC), 28 non-schistosomal chronic cystitis (NSC), and 20 normal control (CTL) subjects. The studied markers in SBT and NSBT were correlated with different clinicopathological criteria namely, tumor histopathology, grading, invasiveness, stage, and presentation of the disease.

Results

SBT was associated with high grade invasive squamous cell carcinoma (SCC) while NSBT was associated with lower grade less invasive transitional cell carcinoma (TCC). The expression of p53, bcl-2, c-myc, and EGFR was higher in SBT than in NSBT while Rb was higher in NSBT than in SBT. However, p16 and ki-67 were not different between SBT and NSBT. The profile of molecular markers in SC was similar to NSC except for EGFR which was higher in SC than in NSC. Both SC and NSC showed higher level of p53, bcl-2, ki-67, and EGFR than in CTL group while p16, Rb, and c-myc were not different. p53 was associated with high grade SCC in both SBT and NSBT. Bcl-2 was associated with high grade invasive tumors in SBT and NSBT. P16 was associated with low grade, late stage, and recurrent SBT and high grade, invasive, late stage, and recurrent NSBT. Rb was associated with SCC in SBT, invasive tumors in NSBT, and late stage and recurrent presentation in both SBT and NSBT. C-myc was associated with high grade, invasive, and late stage SBT and SCC, high grade, invasive, and late stage NSBT. EGFR was associated with invasive SCC in SBT and invasive, high grade, and late stage TCC in NSBT. ki-67 was associated with invasive SBT and high grade late stage NSBT.

Conclusion

SBT and NSBT showed distinct molecular profile of tumor development and progression which can be taken into consideration in fine adjusting the anti-cancer therapy for SBT and NSBT.

An evolutionary perspective on parasitism as a cause of cancer

For the past half-century, the dominant paradigm of oncogenesis has been mutational changes that disregulate cellular control of proliferation. Parasitic causes of cancer were first incorporated into this paradigm by suggesting mechanisms through which parasitism might increase mutational damage, such as generation of mutagenic compounds during immunological activity. The growing recognition of the molecular mechanisms of pathogen-induced oncogenesis and the difficulty of generating oncogenic mutations without first having large populations of dysregulated cells, however, suggests that pathogens, particularly viruses, are major initiators of oncogenesis for many if not most cancers, and that the traditional mutation-driven process becomes the dominant process after this initiation. Molecular phylogenies of individual cancers should facilitate testing of this idea and the identification of causal pathogens.