Prevalence of Cryptosporidium sp. in patients with colorectal cancer.
ABSTRACT Parasitic protozoans of the Cryptosporidium genus are intracellular intestinal parasites of mammals, causing cryptosporidiosis. Clinically, cryptosporidiosis manifests as chronic diarrhoea. Individuals with immune disorders, including those with neoplasms, are at risk of symptomatic invasion.
Was the evaluation of Cryptosporidium sp. prevalence in patients with diagnosed colorectal cancer.
The studied group encompassed 87 patients with diagnosed colorectal cancer, undergoing surgery at the Department of General and Oncological Surgery, Pomeranian Medical University, in the years 2009-2010. Immunoenzymatic tests for Cryptosporidium sp. on faeces samples were performed with the use of commercial test kit, ProSpecT(®)Cryptosporidium Microplate Assay (Remel Inc).
The presence of Cryptosporidium sp. was found in 12.6% of studied patients with colorectal cancer. The performed statistical analysis did not reveal any correlation between Cryptosporidium sp. infection and gender, age, neoplasm advancement stage as per Astler-Coller scale, neoplasm differentiation grade, or neoplastic tumour localisation in relation to the splenic flexure.
There was found high prevalence of Cryptosporidium sp. in patients with colorectal cancer. It was comparable to the prevalence reported for patients with immune deficiency.
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ABSTRACT: Dexamethasone (Dex) treated Severe Combined Immunodeficiency (SCID) mice were previously described as developing digestive adenocarcinoma after massive infection with Cryptosporidium parvum as soon as 45 days post-infection (P.I.). We aimed to determine the minimum number of oocysts capable of inducing infection and thereby gastrointestinal tumors in this model. Mice were challenged with calibrated oocyst suspensions containing intended doses of: 1, 10, 100 or 10(5) oocysts of C. parvum Iowa strain. All administered doses were infective for animals but increasing the oocyst challenge lead to an increase in mice infectivity (P = 0.01). Oocyst shedding was detected at 7 days P.I. after inoculation with more than 10 oocysts, and after 15 days in mice challenged with one oocyst. In groups challenged with lower inocula, parasite growth phase was significantly higher (P = 0.005) compared to mice inoculated with higher doses. After 45 days P.I. all groups of mice had a mean of oocyst shedding superior to 10,000 oocyst/g of feces. The most impressive observation of this study was the demonstration that C. parvum-induced digestive adenocarcinoma could be caused by infection with low doses of Cryptosporidium, even with only one oocyst: in mice inoculated with low doses, neoplastic lesions were detected as early as 45 days P.I. both in the stomach and ileo-caecal region, and these lesions could evolve in an invasive adenocarcinoma. These findings show a great amplification effect of parasites in mouse tissues after challenge with low doses as confirmed by quantitative PCR. The ability of C. parvum to infect mice with one oocyst and to develop digestive adenocarcinoma suggests that other mammalian species including humans could be also susceptible to this process, especially when they are severely immunocompromised.PLoS ONE 12/2012; 7(12):e51232. · 3.53 Impact Factor
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ABSTRACT: Cryptosporidium species are worldwide spread apicomplexan protozoan. These parasites constitute a significant risk to humans and animals. They cause self-limited diarrhea in immunocompetent hosts and a life threatening disease in immunocompromised hosts. Interestingly, Cryptosporidium parvum has been related to digestive carcinogenesis in humans. Consistently with a potential tumorigenic role of this parasite, in an original reproducible animal model of chronic cryptosporidiosis based on dexamethasone-treated or untreated adult SCID mice, we formerly reported that C. parvum (strains of animal and human origin) is able to induce digestive adenocarcinoma even in infections induced with very low inoculum. The aim of this study was to further characterize this animal model and to explore metabolic pathways potentially involved in the development of C. parvum-induced ileo-caecal oncogenesis. We searched for alterations in genes or proteins commonly involved in cell cycle, differentiation or cell migration, such as β-catenin, Apc, E-cadherin, Kras and p53. After infection of animals with C. parvum we demonstrated immunohistochemical abnormal localization of Wnt signaling pathway components and p53. Mutations in the selected loci of studied genes were not found after high-throughput sequencing. Furthermore, alterations in the ultrastructure of adherens junctions of the ileo-caecal neoplastic epithelia of C. parvum infected mice were recorded using transmission electron microscopy. In conclusion, we found for the first time that the Wnt signaling pathway, and particularly the cytoskeleton network seems to be pivotal for the development of C. parvum-induced neoplastic process and cell migration of transformed cells. Furthermore, this model is a valuable tool to contribute to the comprehension of the host-pathogen interactions associated to the intricate infection process due to this parasite, which is able to modulate host cytoskeleton activities and several host-cell biological processes and that remains a significant cause of infection worldwide.Disease Models and Mechanisms 03/2014; · 4.96 Impact Factor
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ABSTRACT: Microbial-triggered inflammation protects against pathogens and yet can paradoxically cause considerable secondary damage to host tissues that can result in tissue fibrosis and carcinogenesis, if persistent. In addition to classical pathogens, gut microbiota bacteria, i.e. a group of mutualistic microorganisms permanently inhabiting the gastrointestinal tract and which plays a key role in digestion, immunity, and cancer prevention, can induce inflammation-associated cancer following the alterations of their microenvironment. Emerging experimental evidence indicates that microbiota members like Escherichia coli and several other genotoxic and mutagenic pathogens can cause DNA damage in various cell types. In addition, the inflammatory response induced by chronic infections with pathogens like the microbiota members Helicobacter spp., which have been associated with liver, colorectal, cervical cancers and lymphoma, for instance, can also trigger carcinogenic processes. A microenvironment including active immune cells releasing high amounts of inflammatory signaling molecules can favor the carcinogenic transformation of host cells. Pivotal molecules released during immune response such as the macrophage migration inhibitory factor (MMIF) and the reactive oxygen and nitrogen species' products superoxide and peroxynitrite, can further damage DNA and cause the accumulation of oncogenic mutations, whereas pro-inflammatory cytokines, adhesion molecules, and growth factors may create a microenvironment promoting neoplastic cell survival and proliferation. Recent findings on the implication of inflammatory signaling pathways in microbial-triggered carcinogenesis as well as the possible role of microbiota modulation in cancer prevention are herein summarized and discussed.Cellular Signalling 10/2012; · 4.47 Impact Factor