31 resultados para Colorectal cancer


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The Sister Mary Joseph (SMJ) nodule is a clinical sign of metastatic cancer involving the umbilicus. The vast majority of these instances represent adenocarcinomas arising from ovarian or colorectal primaries. We present a patient who presented with ascites and the SMJ lesion that turned out to be a metastatic gastrointestinal stromal tumor after fine needle aspiration biopsy was performed. The lesion was subsequently histologically confirmed. Gastrointestinal stroma tumor involving the umbilicus is exceedingly uncommon and only rarely presents in this fashion. The cytomorphological features, differential diagnosis, and comparison with the tissue specimen are made. © 2006 Elsevier Inc. All rights reserved.

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Given that cancer is one of the main causes of death worldwide, many efforts have been directed toward discovering new treatments and approaches to cure or control this group of diseases. Chemotherapy is the main treatment for cancer; however, a conventional schedule based on maximum tolerated dose (MTD) shows several side effects and frequently allows the development of drug resistance. On the other side, low dose chemotherapy involves antiangiogenic and immunomodulatory processes that help host to fight against tumor cells, with lower grade of side effects. In this review, we present evidence that metronomic chemotherapy, based on the frequent administration of low or intermediate doses of chemotherapeutics, can be better than or as efficient as MTD. Finally, we present some data indicating that noncytotoxic concentrations of antineoplastic agents are able to both up-regulate the immune system and increase the susceptibility of tumor cells to cytotoxic T lymphocytes. Taken together, data from the literature provides us with sufficient evidence that low concentrations of selected chemotherapeutic agents, rather than conventional high doses, should be evaluated in combination with immunotherapy. Copyright © 2012 UICC.

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The incidence of colorectal cancer is growing worldwide. The characterization of compounds present in the human diet that can prevent the occurrence of colorectal tumors is vital. The oligosaccharide inulin is such a compound. The aim of this study was to evaluate the antigenotoxic, antimutagenic and anticarcinogenic effects of inulin in vivo. Our study is based on 3 assays that are widely used to evaluate chemoprevention (comet assay, micronucleus assay, and aberrant crypt focus assay) and tests 4 protocols of treatment with inulin (pre-treatment, simultaneous, post-treatment, and pre + continuous). Experiments were carried out in Swiss male mice of reproductive age. In order to induce DNA damage, we used the pro-carcinogenic agent 1,2-dimethylhydrazine. Inulin was administered orally at a concentration of 50 mg/kg body weight following the protocols mentioned above. Inulin was not administered to the control groups. Our data from the micronucleus assay reveal antimutagenic effects of inulin in all protocols. The percentage of inulin-induced damage reduction ranged from 47.25 to 141.75% across protocols. These data suggest that inulin could act through desmutagenic and bio-antimutagenic mechanisms. The anticarcinogenic activity (aberrant crypt focus assay) of inulin was observed in all protocols and the percentages of damage reduction ranged from 55.78 to 87.56% across protocols. Further tests, including human trials, will be necessary before this functional food can be proven to be effective in the prevention and treatment of colon cancer. © FUNPEC-RP.

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Pós-graduação em Bases Gerais da Cirurgia - FMB

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Pós-graduação em Bases Gerais da Cirurgia - FMB

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Pós-graduação em Genética - IBILCE

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Pós-graduação em Patologia - FMB

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Inflammatory bowel disease (IBD) is a chronic and relapsing disease caused by exaggerated response of the immune system. It represents a significant health problem by limiting the quality of life and being the main risk factor for colorectal cancer. Despite of its importance, the high worldwide incidence and being the object of research for several decades, the etiology remains unknown. Studies indicates an interaction between genetic and environmental factors which together with the intestinal microbiota, leads to an uncontrolled immune response. One of the aggravating environmental factors often discussed is stress, as the daily life of the population in general is increasingly rushed. In order to demonstrate the influence of stress on IBD, this study aimed to standardize an experimental model of colitis induced by instillation of a trinitrobenzene sulfonic acid (TNBS) noninflammatory concentration plus exposure to stress that intensify the inflammation. Therefore, an experiment was done to determine what would be the noninflammatory concentration. In this step, four different concentrations of TNBS (1, 6, 12.5 or 40mg/ml) were tested and the lowest concentration capable of inducing a noninflammatory response in the gut was defined as 1 mg/ml. Then, a second experiment was performed which induced colitis and exposed the animals to restraint stress. The results, however, showed that this stimulus was not enough to exacerbate the damage caused by the 1 mg/ml concentration of TNBS in the colon. With some changes in the protocol, the third experiment associated cold and restraint, as well as changes on the day of euthanasia, which occurred immediately after the stress session. The results of myeloperoxidase activity measurement were unexpected due to the noninflammatory concentration of TNBS caused an intestinal inflammation similar to the concentration of 40 mg/ml. However, the results of glutathione quantification and the corticosterone ...

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Bacillus thuringiensis (Bt), is an environmental Gram-positive spore-forming bacterium that produces crystalline parasporal protein (Cry) during sporulation. The inclusions often exhibit strong and specific insecticidal activity, making Bt an agent for agricultural controlling insects pest, mites, protozoa and nematodes. Recent studies reported that some of these Crys do not show cytotoxicity against insects but they are capable to kill some human and animal cancer cells. These proteins were denominated parasporins (PS). However, antitumor activity of Bt parasporin on the development of murine colorectal cancer (CT-26), are not well studies and these are no reports on the in vivo effect of these proteins. Thus, the present study evaluated the in vitro and in vivo anti-tumoral activity of Bt parasporin against the murine colorectal cancer line CT-26. Therefore, Balb/c mice were s.c. inoculated with CT-26 cells and weekly treated with parasporin (i.p.) pre-activated by enzymatic digestion with trypsin or proteinase K. Our results have shown, for the first time, that despite the anti-tumor activity in vitro, parasporin crystals couldn’t combat tumor growth in vivo. Instead, this protein was highly toxic, affecting the liver and spleen, with possible effect on other organs, decreasing the survival of treated animals. The results indicate the need for studies to better detoxification or manipulation of parasporin for therapeutic use and new studies for analysis of toxicological effects of repetitive exposure of farmers to this toxin

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Our previous studies have shown that low concentrations (noncytotoxics) of antineoplastic agents modulate positively the dendritic cells, favoring their in vitro maturation and improving their antigen presenting function. The effects on colorectal cancer cells (HCT-116) were also investigated and we have observed an increased immunogenicity and susceptibility to cytotoxic T cells. Thereby, this study aimed to investigate the effect of 5-fluorouracil (5-FU) an azacitidine (AZA), in minimum effective and noncytotoxic concentrations on lymphocytes of healthy donors. In this study we have analyzed the cytotoxic effect of drugs at these concentrations as well as the proliferative ability of lymphocytes. In vitro production of IL-10 and IFN-γ has been also evaluated. We have observed that low concentrations of those chemotherapeutic agents are not cytotoxic for lymphocytes. However, the minimum effective concentrations (5-FU: 0,410±0,088 e AZA: 0,757±0,233; p<0, 05) have reduced the cell number. Proliferative activity of allogeneic lymphocytes in a mixed reaction (MLR) was not affected by the treatment. The cytokine production was not affected by the treatments, either. In conclusion, low concentrations of 5-FU and AZA has no deleterious effects on human peripheral blood lymphocytes and seems to be safe for combinatory administration with DC vaccines

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)