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Query: UMLS:C0009402 (colorectal cancer)
 53,228 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Primary hypomagnesemia constitutes a rare heterogeneous group of disorders characterized by renal or intestinal magnesium (Mg(2+)) wasting resulting in generally shared symptoms of Mg(2+) depletion, such as tetany and generalized convulsions, and often including associated disturbances in calcium excretion. However, most of the genes involved in the physiology of Mg(2+) handling are unknown. Through the discovery of a mutation in the EGF gene in isolated autosomal recessive renal hypomagnesemia, we have, for what we believe is the first time, identified a magnesiotropic hormone crucial for total body Mg(2+) balance. The mutation leads to impaired basolateral sorting of pro-EGF. As a consequence, the renal EGFR is inadequately stimulated, resulting in insufficient activation of the epithelial Mg(2+) channel TRPM6 (transient receptor potential cation channel, subfamily M, member 6) and thereby Mg(2+) loss. Furthermore, we show that colorectal cancer patients treated with cetuximab, an antagonist of the EGFR, develop hypomagnesemia, emphasizing the significance of EGF in maintaining Mg(2+) balance.
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PMID:Impaired basolateral sorting of pro-EGF causes isolated recessive renal hypomagnesemia. 1767 46

In the present study the expression of LRIG1 (leucine rich repeats and immunoglobin-like domains 1) and its relation to EGFR (epidermal growth factor receptor) was examined in tumour samples and adjacent non-neoplastic tissues from 30 patients with colorectal cancer. The LRIG1 gene, at chromosome 3p14, encodes an intergral membrane protein, which counteracts signalling by receptor tyrosine kinases belonging to the ERBB (epidermal growth factor receptor) family. LRIG1 is expressed in all tissues and organs analysed to date, including breast, brain, skin, kidney, spleen and colon. Overexpression of EGFR is seen in 70 - 90% of colorectal cancers, and is associated with a poor survival. Western blot analysis showed LRIG1 upregulation in 43% and downregulation in 43% of the colorectal cancers compared to adjacent non-neoplastic tissue. No correlation was evident between LRIG1, analysed by Western Blot and the expression of EGFR analysed by immunohistochemistry. FISH (fluoroscence in situ hybridisAtion) analysis showed increased LRIG1 copy number in one of nine tumours. Four colorectal cancer cell lines demonstrated two LRIG1 gene copies. In conclusion, there was a great heterogeneity in the expression of the LRIG1 protein in colorectal cancer, which was not related to gene dosage of the LRIG1 gene. Further studies can be of interest to evaluate whether alteration in LRIG1 expression in colorectal cancer is of biological or clinical significance.
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PMID:LRIG1 expression in colorectal cancer. 1785 70

New cancer-specific therapies are based on specific molecular alterations of malignant tumors which are targeted by small inhibitory molecules or specific antibodies. During the development of these agents potential molecular targets are characterized for their expression and importance for pathogenesis and clinical course of the disease. Frequently the assumption is made that the degree of expression of the target protein or the molecular alteration of the target gene allows a prediction if a certain patient will profit from the therapy against this specific protein or not. The first example was that breast cancer patients with overexpression and/or amplification of Her-2 respond to a Her-2-specific antibody (Herceptin) therapy. The expression or activation of the Epidermal Growth Factor Receptor (EGFR, Her-1) are altered in many epithelial tumours and clinical studies indicate that they have important roles in tumor aetiology and progression. Several EGFR-specific monoclonal antibodies and specific tyrosine kinase inhibitors were developed in the last years. Cetuximab is approved for the treatment of metastatic colorectal cancer and advanced squamous cell carcinoma of the head and neck and is investigated in numerous trials for other tumors. The expression of EGFR in the tumor was a prerequisite for the therapy in the first trials, giving the pathologist a central role in treatment decision. However, recent data clearly demonstrate that the degree of EGFR expression does not correlate with therapy response. Therefore a therapy should be not denied to a individual patient solely because of lack of EGFR expression in the tumor. Tyrosine kinase inhibitors (e. g. Gefitinib, Erlotinib) are effective in the treatment of non small cell lung cancer and also investigated in ongoing trials in many cancer types. The correlation of therapy response with both specific molecular alterations (EGFR tyrosine kinase domain mutations) and clinicopathological features (Asian ethnicity, women, non-smokers, bronchioloalveolar differentation) is a good example of the potential role of predictive molecular pathology in the future.
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PMID:[Role of predictive pathology in oncology--example of new therapies targeting EGFR]. 1786 89

Curcumin (diferuloylmethane), which has been shown to inhibit growth of transformed cells, has no discernible toxicity and achieves high levels in colonic mucosa. 5-fluorouracil (5-FU) or 5-FU plus oxaliplatin (FOLFOX) remains the backbone of colorectal cancer chemotherapeutics, but with limited success. The present investigation was, therefore, undertaken to examine whether curcumin in combination with conventional chemotherapeutic agent(s)/regimen will be a superior therapeutic strategy for colorectal cancer. Indeed, results of our in vitro studies demonstrated that curcumin together with FOLFOX produced a significantly greater inhibition (p < 0.01) of growth and stimulated apoptosis (p < 0.001) of colon cancer HCT-116 and HT-29 cells than that caused by curcumin, 5-FU, curcumin + 5-FU or FOLFOX. These changes were associated with decreased expression and activation (tyrosine phosphorylation) of EGFR, HER-2, HER-3 (72-100%) and IGF-1R (67%) as well as their downstream effectors such as Akt and cycloxygenase-2 (51-97%). Furthermore, while these agents produced a 2-3-fold increase in the expression of IGF-binding protein-3 (IGFBP-3), curcumin together with FOLFOX caused a 5-fold increase in the same, when compared to controls. This in turn led to increased sequestration of IGF by IGFBP-3 rendering IGF-1 unavailable for binding to and activation of IGF-1R. We conclude that the superior effects of the combination therapy of curcumin and FOLFOX are due to attenuation of EGFRs and IGF-1R signaling pathways. We also suggest that inclusion of curcumin to the conventional chemotherapeutic agent(s)/regimen could be an effective therapeutic strategy for colorectal cancer.
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PMID:Curcumin enhances the effects of 5-fluorouracil and oxaliplatin in mediating growth inhibition of colon cancer cells by modulating EGFR and IGF-1R. 1791 58

Colorectal cancer (CRC) is a major cause of cancer morbidity and mortality, and elucidation of its underlying genetics has advanced diagnostic screening, early detection, and treatment. Because CRC genomes are characterized by numerous non-random chromosomal structural alterations, we sought to delimit regions of recurrent amplifications and deletions in a collection of 42 primary specimens and 37 tumor cell lines derived from chromosomal instability neoplasia and microsatellite instability neoplasia CRC subtypes and to compare the pattern of genomic aberrations in CRC with those in other cancers. Application of oligomer-based array-comparative genome hybridization and custom analytic tools identified 50 minimal common regions (MCRs) of copy number alterations, 28 amplifications, and 22 deletions. Fifteen were highly recurrent and focal (<12 genes) MCRs, five of them harboring known CRC genes including EGFR and MYC with the remaining 10 containing a total of 65 resident genes with established links to cancer. Furthermore, comparisons of these delimited genomic profiles revealed that 22 of the 50 CRC MCRs are also present in lung cancer, glioblastoma, and/or multiple myeloma. Among 22 shared MCRs, nine do not contain genes previously shown genetically altered in cancer, whereas the remaining 13 harbor 35 known cancer genes, of which only 14 have been linked to CRC pathogenesis. Together, these observations point to the existence of many yet-to-be discovered cancer genes driving CRC development, as well as other human cancers, and show the utility of high-resolution copy number analysis in the identification of genetic events common and specific to the development of various tumor types.
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PMID:Common and distinct genomic events in sporadic colorectal cancer and diverse cancer types. 1800 16

Interesting activity has been reported by combining chemotherapy with cetuximab. An alternative approach for blocking EGFR function has been the development of small-molecule inhibitors of tyrosine kinase domain such as gefitinib. We designed a multicentre phase II study in advanced colorectal cancer combining gefitinib+FOLFOX in order to determine the activity and to relate EGFR expression and gene amplification and NF-kB activation to therapeutic results. Patients received FOLFOX-4 regimen plus gefitinib as first-line treatment. Tumour samples were analysed for EGFR protein expression by immunohistochemical analysis and for EGFR gene amplification by fluorescence in situ hybridisation (FISH), chromogenic in situ hybridisation (CISH) and NF-kB activation. Forty-three patients were enrolled into this study; 15 patients experienced a partial response (response rate=34.9%), whereas other 12 (27.9%) had a stable disease. Median progression-free survival (PFS) was 7.8 months and median overall survival (OS) was 13.9 months. We did not find any relationship with EGFR overexpression, gene amplification, while NF-kB activation was associated with a resistance to therapy. Gefitinib does not seem to increase the activity of FOLFOX in advanced colorectal cancer even in patients overexpressing EGFR or with EGFR amplification. Furthermore, while NF-kB activation seems to predict resistance to chemotherapy as demonstrated 'in vitro' models, gefitinib does not overcome this mechanism of resistance, as reported for cetuximab.
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PMID:A combination of gefitinib and FOLFOX-4 as first-line treatment in advanced colorectal cancer patients. A GISCAD multicentre phase II study including a biological analysis of EGFR overexpression, amplification and NF-kB activation. 1805 97

EGFR overexpression usually correlates with a more advanced disease stage, a poorer prognosis and a worse chemotherapy response. EGFR expression increase has been observed in many tumours. For all the aforementioned reasons, EGFR inhibition can be considered an attractive approach in cancer treatment. One strategy has been receptor inhibition of extracellular domain using monoclonal antibodies. Cetuximab is the most developed one and there is plenty information on the literature about its current status. In this review we focus on other EGFR monoclonal antibodies under clinical development. The more developed one is Panitumumab. Its clinical development is taking place very quickly and it has mainly been studied in colorectal cancer showing promising results. There are also other interesting drugs such as Matuzumab, Nimotuzumab and Zalutumumab.
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PMID:Current situation of Panitumumab, Matuzumab, Nimotuzumab and Zalutumumab. 1809 77

Results published in 2007 improve treatments in digestive oncology. In esophageal cancer, efficacy of preoperative chemotherapy or radiochemotherapy is confirmed. In locally advanced esophageal cancer it has been proved that the definitive radiochemotherapy is an alternative at radiochemotherapy plus surgery. Two majors data have been presented for patients with metastatic colorectal cancer: monochemotherapy for the first line is back; molecular marker is necessary to optimize the use of anti EGFR antibody. Lastly, the first effective medical treatment of hepatocellular carcinoma has been presented.
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PMID:[News in digestive oncology]. 1823 May 77

Among the targeted therapies used in the treatment of metastatic colorectal cancer (CRC), cetuximab was registered in France in 2004. This chimeric antibody inhibiting the Epidermal Growth receptor (EGFR) has been demonstrated to be efficient in the treatment of irinotecan-resistant metastatic CRC expressing the EGFR. Panitumumab, a fully humanized anti-EGFR antibody should soon be registered after failure of conventional chemotherapies. However, these costly and potentially toxic treatments are efficient in a little proportion of patients. It is so necessary to identify some factors able to better define whose patients will benefit from these treatments. The major potential predictive factors of response to cetuximab and/or panitumumab that have been evaluated in the literature, which are summarized in this review, are molecular factors involved more or less directly in the EGF signaling pathway. Among them, KRAS mutations, EGFR gene copy number and, more recently, epiregulin and amphiregulin expression are those, along with skin toxicity, which appear to be the most relevant and which will have to be evaluated in future clinical trials to be validated before being incorporated in therapeutic strategy of CRC.
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PMID:[Predictive factors of response to anti-EGFR treatments in colorectal cancer]. 1823 May 79

The human epidermal growth factor receptor (HER1/EGFR/ErbB1) signaling is aberrant and overexpressed in many solid malignancies making it an appealing target for biologic agents. Among the classes of drugs targeting EGFR are monoclonal antibodies and EGFR tyrosine kinase inhibitors, which have been shown effective and generally well tolerated in different clinical settings. The majority of patients treated with EGFR inhibitors (EGFRIs) develop specific dose-dependent skin toxicity. This side effect may lead to physical and psychosocial discomfort which can result in dose reduction or treatment interruption. The relationship between rash and clinical outcome has stimulated interest in this particular toxicity as a possible surrogate marker of efficacy in patients treated with targeted agents against EGFR. This review aims to summarize and update the current knowledge of the clinical presentation, predictive and prognostic value, and the management of EGFRI-related skin toxicity.
Clin Colorectal Cancer 2008 Jan
PMID:Epidermal growth factor receptor inhibitor-related skin toxicity: mechanisms, treatment, and its potential role as a predictive marker. 1827 75


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