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CA IX (ca + ix)
Selected AbstractsHypoxia-inducible factor-1, in non small cell lung cancer: Relation to growth factor, protease and apoptosis pathwaysINTERNATIONAL JOURNAL OF CANCER, Issue 1 2004Daniel E.B. Swinson Abstract Hypoxia-inducible factor (HIF)-1, is the regulatory subunit of HIF-1 that is stabilized under hypoxic conditions. Under different circumstances, HIF-1, may promote both tumorigenesis and apoptosis. There is conflicting data on the importance of HIF-1, as a prognostic factor. This study evaluated HIF-1, expression in 172 consecutive patients with stage I,IIIA non small cell lung cancer (NSCLC) using standard immunohistochemical techniques. The extent of HIF-1, nuclear immunostaining was determined using light microscopy and the results were analyzed using the median (5%) as a low cut-point and 60% as a high positive cut-point. Using the low cut-point, positive associations were found with epidermal growth factor receptor (EGFR; p = 0.01), matrix metalloproteinase (MMP)-9 (p = 0.003), membranous (p < 0.001) and perinuclear (p = 0.004) carbonic anhydrase (CA) IX, p53 (p = 0.008), T-stage (p = 0.042), tumor necrosis (TN; p < 0.001) and squamous histology (p < 0.001). No significant association was found with Bcl-2 or either N- or overall TMN stage or prognosis. When the high positive cut-point was used, HIF-1, was associated with a poor prognosis (p = 0.034). In conclusion, the associations with EGFR, MMP-9, p53 and CA IX suggest that these factors may either regulate or be regulated by HIF-1,. The association with TN and squamous-type histology, which is relatively more necrotic than other NSCLC types, reflects the role of hypoxia in the regulation of HIF-1,. The prognostic data may reflect a change in the behavior of HIF-1, in increasingly hypoxic environments. © 2004 Wiley-Liss, Inc. [source] Carbonic anhydrase IX: A new druggable target for the design of antitumor agentsMEDICINAL RESEARCH REVIEWS, Issue 3 2008Jean-Yves Winum Abstract Carbonic anhydrases (CAs, EC 4.2.1.1) are a family of enzymes widespread in all life kingdoms. In mammals, isozyme CA IX is highly overexpressed in many cancer types being present in few normal tissues. Its expression is strongly induced by hypoxia present in many tumors, being regulated by the HIF transcription factor and correlated with a poor response to classical chemo- and radiotherapies. CA IX was recently shown to contribute to acidification of the tumor environment, by efficiently catalyzing the hydration of carbon dioxide to bicarbonate and protons with its extracellularly situated active site, leading both to the acquisition of metastasic phenotypes and to chemoresistance with weakly basic anticancer drugs. Inhibition of this enzymatic activity by specific and potent inhibitors was shown to revert these acidification processes, establishing a clear-cut role of CA IX in tumorigenesis. The development of a wide range of potent and selective CA IX inhibitors belonging to diverse chemical classes, such as membrane-impermeant, fluorescent or metal-containing such agents, could thus provide useful tools for highlighting the exact role of CA IX in hypoxic cancers, to control the pH (im)balance of tumor cells, and to develop novel diagnostic or therapeutic applications for the management of tumors. Indeed, both fluorescent inhibitors or positively charged, membrane impermeant sulfonamides have been recently developed as potent CA IX inhibitors and used as proof-of-concept tools for demonstrating that CA IX constitutes a novel and interesting target for the anticancer drug development. © 2007 Wiley Periodicals, Inc. Med Res Rev, 28, No. 3, 445,463, 2008 [source] Sulfamates and their therapeutic potentialMEDICINAL RESEARCH REVIEWS, Issue 2 2005Jean-Yves Winum Abstract Starting from the very simple molecule sulfamic acid, O -substituted-, N -substituted-, or di-/tri-substituted sulfamates may be obtained, which show specific biological activities which were or started to be exploited for the design of many types of therapeutic agents. Among them, sulfamate inhibitors of aminoacyl-tRNA synthetases (aaRSs) were recently reported, constituting completely new classes of antibiotics, useful in the fight of drug-resistant infections. Anti-viral agents incorporating sulfamate moieties have also been obtained, with at least two types of such derivatives investigated: the nucleoside/nucleotide human immunodeficiency virus (HIV) reverse transcriptase inhibitors, and the HIV protease inhibitors (PIs). In the increasing armamentarium of anti-cancer drugs, the sulfamates occupy a special position, with at least two important targets evidenced so far: the steroid sulfatases (STSs) and the carbonic anhydrases (CAs). An impressing number of inhibitors of STSs of the sulfamate type have been reported in the last years, with several compounds, such as 667COUMATE among others, progressing to clinical trials for the treatment of hormone-dependent tumors (breast and prostate cancers). This field is rapidly evolving, with many types of new inhibitors being constantly reported and designed in such a way as to increase their anti-tumor properties, and decrease undesired features (for example, estrogenicity, a problem encountered with the first generation such inhibitors, such as EMATE). Among the many isozymes of CAs, at least two, CA IX and CA XII, are highly overexpressed in tumors, being generally absent in the normal tissues. Inhibition of tumor-associated CAs was hypothesized to lead to novel therapeutic approaches for the treatment of cancer. Many sulfamates act as very potent (low nanomolar) CA inhibitors. The X-ray crystal structure of the best-studied isozyme, CA II, with three sulfamates (sulfamic acid, topiramate, and EMATE) has recently been reported, which allowed for a rationale drug design of new inhibitors. Indeed, low nanomolar CA IX inhibitors of the sulfamate type have been reported, although such compounds also act as efficient inhibitors of isozymes CA I and II, which are not associated with tumors. A large number of anti-convulsant sulfamates have been described, with one such compound, topiramate, being widely used clinically as anti-epileptic drug. By taking into consideration a side effect of topiramate, an anti-epileptic drug leading to weight loss in some patients, it has recently been proposed to use this drug and related sulfamates for the treatment of obesity. The rationale of this use is based on the inhibition of the mitochondrial CA isozyme, CA V, involved in lipogenesis. Some sulfamates were also shown to possess potent inhibitory activity against acyl coenzyme A:cholesterol acyltransferase, an enzyme involved in cholesterol metabolism. One such agent, avasimibe, is in advanced clinical trials for the treatment of hyperlipidemia and atherosclerosis. Thus, the sulfamate moiety offers very attractive possibilities for the drug design of various pharmacological agents, which are on one hand due to the relative ease with which such compounds are synthesized, and on the other one, due to the fact that biological activity of most of them is impressive. © 2004 Wiley Periodicals, Inc. [source] 34 In vivo tumour hypoxia and carbonic anhydrase IX expression in xenografted human renal cell carcinoma animal models using probes, 124I-G250 pet, biodistribution and immunohistochemistry immunobiodistribution, and oxygen studiesBJU INTERNATIONAL, Issue 2006N. LAWRENTSCHUK Introduction:, Hypoxia stimulates angiogenesis and has been demonstrated in tumours where it correlates with resistance to treatment and poor prognosis. We have previously demonstrated hypoxia in human Renal Cell Carcinoma (RCC). The purpose of animal models was to further evaluate oxygen levels within RCC whilst also focusing on expression of the protein carbonic anhydrase IX (CA IX). This protein is stimulated by hypoxia and involved in angiogenesis and may be a potential tumour target for imaging and future therapies. Methods:, Balb/c nude mice had human RCC (SK-RC-52) xenografted subcutaneously. Tumours were grown to different volumes with oxygen levels measured. Further groups then had the radiolabelled monoclonal antibody 124I-G250 (that binds to CA IX) injected intravenously and had Positron Emission Tomography (PET), gamma counting and oxygen studies performed on days 0,1,2,3,5,7,10 and 14 post injection. Immunohistochemistry and autoradiography was also performed. Results:, An inverse relationship between tumour volume and hypoxia within the model was established (P < 0.001). Furthermore, CA IX was expressed by tumours with maximal uptake of 124I-G250 on days 2/3 by distribution with gamma counting that could be correlated with uptake on PET imaging. Conclusions:, The xenograft model confirms human RCC are hypoxic. Also, that the level of hypoxia is inversely proportional to tumour sise. A correlation was made between PET scanning with 124I-G250 and biodistribution within tumours by gamma counting confirming CAIX as an imaging and potential therapeutic target in RCC. [source] | ||||||||||