22 research outputs found
Infiammazione e cancro: l'interazione COX-2/CA-IX promuove il potenziale invasivo e la sopravvivenza in ipossia delle cellule del cancro colon-rettale
Cyclooxygenase-2/Carbonic anhydrase-IX up-regulation promotes invasive potential and hypoxia survival in colorectal cancer cells
Purpose: Cyclooxygenase-2 (COX-2) is a major mediator of inflammation, playing a pivotal role in colorectal carcinogenesis. Hypoxia is an universal hallmark of solid tumour in vivo. This investigation was prompted by the observation that in colorectal cancer cells the expression of COX-2 protein is positively correlated with that of the hypoxia survival gene Carbonic Anhydrase-IX (CA-IX).
Experimental Design: Since COX-2 gene expression and activity is increased in hypoxia, and that CA-IX is expressed also in normoxia in colorectal cancer cells, we tested the hypothesis that COX-2 activity in normoxia, as well as in hypoxia may be functionally linked to that of CA-IX gene. We investigated the role of COX-2 and CA-IX in colorectal cancer cell lines. In this regard, we performed RNA interference to knockdown COX-2 gene in vitro and immunohistochemistry to evaluate the protein expression of COX-2 and CA-IX in human colon cancer tissue specimens ex vivo.
Results: We found that COX-2, by PGE2 production, controls CA-IX gene expression in an ERK dependent manner. In line with this finding, we also showed that the COX-2 inhibition by a specific short harpin COX-2 RNA (shCOX-2) or by a specific drug (SC-236), down-regulated CA-IX expression in colon cancer cells. We then exposed colon cancer cells to hypoxia stimuli and found that COX-2/CA-IX interplay promoted hypoxia survival. Moreover, we also report that COX-2/CA-IX interplay triggers Matrix Metalloproteinase 2/9 (MMP-2/9) activation and enhances the invasiveness of colorectal cancer cells. Thus given our above observations, we found that CA-IX and COX-2 protein expressions correlate with more aggressive stage colorectal cancer tissues ex vivo.
Conclusions: Taken together these data indicate that COX-2/CA-IX interplay promotes an aggressive phenotype (hypoxia survival and invasiveness) which can be modulated in vitro by COX-2 selective inhibition and which may play a role in determining the biological aggressiveness of colorectal tumours. Moreover, in vitro and ex vivo data also suggest that the signatures of inflammation (COX-2) and hypoxia (CA-IX) may be difficult to be disentangled in colon cancer, being both responsible for the up-regulation of the same pathways
Evaluation of Modified PEG-Anilinoquinazoline Derivatives as Potential Agents for EGFR Imaging in Cancer by Small Animal PET
Purpose: The in vivo evaluation of three modified polyethylene glycol (PEG)-anilinoquinazoline derivatives labeled with 124 I, 18 F, and 11 C as potential positron emission tomography (PET) bioprobes for visualizing epidermal growth factor receptor (EGFR) in cancer using small animal PET. Procedures: Xenograft mice with the human glioblastoma cell lines U138MG (lacking EGFR expression) and U87MG.wtEGFR (transfected with an overexpressing human wild-type EGFR gene) were used. Static and dynamic PET imaging was conducted for all three PEGylated compounds. Tumor necrosis, microvessel density, and EGFR levels were evaluated by histopathology and enzyme-linked immunosorbent assay. Results: Nineteen animal models were generated (two U138MG, three U87MG, 14 with both U138MG and U87MG bilateral masses). In static images, a slight increase in tracer uptake was observed in tumors, but in general, there was no retention of tracer uptake over time and no difference in uptake between U138MG and U87MG masses. In addition, no significant uptake was demonstrated in dynamic scans of the 18 F-PEG tracer. No necrosis was present except in four animals. MVD was 9.6 and 48 microvessels/×400 field in the U138GM and U87GM masses
Clinical and diagnostic aspects of gluten related disorders
none6noGluten is one of the most abundant and widely distributed components of food in many areas. It can be included in wheat, barley, rye, and grains such as oats, barley, spelt, kamut, and triticale. Gluten-containing grains are widely consumed; in particular, wheat is one of the world's primary sources of food, providing up to 50% of the caloric intake in both industrialized and developing countries. Until two decades ago, celiac disease (CD) and other gluten-related disorders were believed to be exceedingly rare outside of Europe and were relatively ignored by health professionals and the global media. In recent years, however, the discovery of important diagnostic and pathogenic milestones led CD from obscurity to global prominence. In addition, interestingly, people feeding themselves with gluten-free products greatly outnumber patients affected by CD, fuelling a global consumption of gluten-free foods with approximately $2.5 billion in United States sales each year. The acknowledgment of other medical conditions related to gluten that has arisen as health problems, providing a wide spectrum of gluten-related disorders. In February 2011, a new nomenclature for gluten-related disorders was created at a consensus conference in London. In this review, we analyse innovations in the field of research that emerged after the creation of the new classification, with particular attention to the new European Society for Paediatric Gastroenterology, Hepatology and Nutrition guidelines for CD and the most recent research about non-celiac gluten sensitivity.openTovoli, Francesco; Masi, Chiara; Guidetti, Elena; Negrini, Giulia; Paterini, Paola; Bolondi, LuigiTovoli, Francesco; Masi, Chiara; Guidetti, Elena; Negrini, Giulia; Paterini, Paola; Bolondi, Luig
Seronegative celiac disease: Shedding light on an obscure clinical entity
Background Although serological tests are useful for identifying celiac disease, it is well established that a minority of celiacs are seronegative. Aim To define the prevalence and features of seronegative compared to seropositive celiac disease, and to establish whether celiac disease is a common cause of seronegative villous atrophy. Methods Starting from 810 celiac disease diagnoses, seronegative patients were retrospectively characterized for clinical, histological and laboratory findings. Results Of the 810 patients, fourteen fulfilled the diagnostic criteria for seronegative celiac disease based on antibody negativity, villous atrophy, HLA-DQ2/-DQ8 positivity and clinical/histological improvement after gluten free diet. Compared to seropositive, seronegative celiac disease showed a significantly higher median age at diagnosis and a higher prevalence of classical phenotype (i.e., malabsorption), autoimmune disorders and severe villous atrophy. The most frequent diagnosis in the 31 cases with seronegative flat mucosa was celiac disease (45%), whereas other diagnoses were Giardiasis (20%), common variable immunodeficiency (16%) and autoimmune enteropathy (10%). Conclusions Although rare seronegative celiac disease can be regarded as the most frequent cause of seronegative villous atrophy being characterized by a high median age at diagnosis; a close association with malabsorption and flat mucosa; and a high prevalence of autoimmune disorders
Autoimmune enteropathy: not all flat mucosa mean coeliac disease
A 62-year-old woman complaining of severe malabsorption was diagnosed with celiac disease based on the findings of flat, small intestinal mucosa and HLA-DQ2 positivity, although celiac serology was negative. This diagnosis was questioned due to the lack of clinical and histological improvement after a long period of strict gluten-free diet. The detection of enterocyte autoantibodies guided to the correct diagnosis of autoimmune enteropathy, leading to a complete recovery of the patient following an appropriate immunosuppressive treatment. Autoimmune enteropathy should be considered in the differential diagnosis of malabsorption with severe villous atrophy, including those cases with negative celiac-related serology
Molecular detection of epidermal growth factor receptor in colorectal cancer: does it still make sense? (Review)
AIM: The aim of the study was to detect and compare the epidermal growth factor receptor (EGFr) content using different methods, to establish whether the quantitative detection and functional study of EGFr in colorectal cancer, using methods other than immunohistochemistry (IHC), are appropriate.
METHOD: Analysis of EGFr by IHC was performed in 230 colorectal cancer patients using monoclonal anti-EGFr. Total and activated EGFr (pY1068) contents were determined in 92 patients and real-time PCR, to determine the level of EGFr messenger RNA, was carried out in 60 patients.
RESULTS: There was no association between EGFr IHC groups and the mean total EGFr levels measured using ELISA.
CONCLUSION: The study shows that the results of different EGFr detection methods do not correlate with each other. Hence, the real role of EGFr in colorectal cancer remains unsettled. Clinically, the receptor itself does not seem to be important and it would be better to focus on EGFr signalling in downstream pathways