Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0699790 (colon cancer)
 28,837 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Inhibition of a single transduction pathway is often inefficient due to activation of alternative signalling. The mammalian target of rapamycin (mTOR) is a key intracellular kinase integrating proliferation, survival and angiogenic pathways and has been implicated in the resistance to EGFR inhibitors. Thus, mTOR blockade is pursued to interfere at multiple levels with tumour growth. We used everolimus (RAD001) to inhibit mTOR, alone or in combination with anti-EGFR drugs gefitinib or cetuximab, on human cancer cell lines sensitive and resistant to EGFR inhibitors, both in vitro and in vivo. We demonstrated that everolimus is active against EGFR-resistant cancer cell lines and partially restores the ability of EGFR inhibitors to inhibit growth and survival. Everolimus reduces the expression of EGFR-related signalling effectors and VEGF production, inhibiting proliferation and capillary tube formation of endothelial cells, both alone and in combination with gefitinib. Finally, combination of everolimus and gefitinib inhibits growth of GEO and GEO-GR (gefitinib resistant) colon cancer xenografts, activation of signalling proteins and VEGF secretion. Targeting mTOR pathway with everolimus overcomes resistance to EGFR inhibitors and produces a cooperative effect with EGFR inhibitors, providing a valid therapeutic strategy to be tested in a clinical setting.
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PMID:Inhibition of mTOR pathway by everolimus cooperates with EGFR inhibitors in human tumours sensitive and resistant to anti-EGFR drugs. 1831 15

A library of 24 derivatives designed by combining two natural products-derived fragments was prepared and tested to determine their anticancer potential in HT29 colon cancer cells. All library members inhibit cell proliferation as measured by MTT mitochondrial functional assay, with IC50 values in the 1-100 microM range. Entry 1b caused apoptotic EGFR-mediated intracellular signaling. Thus, polyamino-quinones emerged as readily accessible and easily diversified scaffolds for anticancer lead discovery.
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PMID:Parallel synthesis and cytotoxicity evaluation of a polyamine-quinone conjugates library. 1869 55

It is becoming increasingly evident that cancer stem cells play a vital role in development and progression of cancers and relapse following chemotherapy. The present study examines the presence of cancer stem-like cells (CSC) in adenomatous polyps and in normal appearing colonic mucosa in humans during aging. The number of polyps was found to increase linearly with advancing age (r(2)=0.92, p<0.02). Immunohistochemical analysis revealed co-localization of CSC markers CD44 and CD166 in colonic polyps. Real-time RT-PCR analysis of normal appearing mucosa from subjects with adenomatous polyps showed an age-related rise in CSC as evidenced by the increased expression of CD44, CD166 and ESA. A similar phenomenon was also observed for EGFR. In addition, the expression each CSC marker was found to be about 2-fold higher in subjects with 3-4 polyps than those with 1-2 polyps. In conclusion, our results show that colon cancer stem-like cells are present in the premalignant adenomatous polyps as well in normal appearing colonic mucosa. Moreover, our observation of the age-related rise in CSC in macroscopically normal colonic mucosa suggests a predisposition of the organ to developing colorectal cancer.
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PMID:Age-related increase in colorectal cancer stem cells in macroscopically normal mucosa of patients with adenomas: a risk factor for colon cancer. 1901 Mar 7

Previously, we showed that ACh-induced proliferation of human colon cancer cells is mediated by transactivation of epidermal growth factor (EGF) receptors (EGFRs). In the present study, we elucidate the molecular mechanism underlying this action. ACh-induced proliferation of H508 colon cancer cells, which express exclusively M3 muscarinic receptors (M3Rs), was attenuated by anti-EGFR ligand binding domain antibody, a broad-spectrum matrix metalloproteinase (MMP) inhibitor, anti-MMP7 antibody, a diphtheria toxin analog that blocks release of an EGFR ligand [heparin-binding EGF-like growth factor (HBEGF)], and anti-HBEGF antibody. Conditioned media from ACh-treated H508 cells induced proliferation of SNU-C4 colon cancer cells that express EGFR but not M3R. These actions were attenuated by an EGFR inhibitor and by anti-EGFR and anti-HBEGF antibodies. In H508, but not SNU-C4, colon cancer cells, ACh caused a striking dose- and time-dependent increase in levels of MMP7 mRNA and MMP7 protein. Similarly, ACh induced robust MMP1 and MMP10 gene transcription. ACh-induced MMP1, MMP7, and MMP10 gene transcription was attenuated by atropine, anti-EGFR antibody, and chemical inhibitors of EGFR and ERK activation. In contrast, inhibitors of phosphatidylinositol 3-kinase and NF-kappaB activation did not alter MMP gene transcription. Collectively, these findings indicate that MMP7-catalyzed release of HBEGF mediates ACh-induced transactivation of EGFR and consequent proliferation of colon cancer cells. ACh-induced activation of EGFR and downstream ERK signaling also regulates transcriptional activation of MMP7, thereby identifying a novel feed-forward mechanism for neoplastic cell proliferation.
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PMID:Acetylcholine-induced activation of M3 muscarinic receptors stimulates robust matrix metalloproteinase gene expression in human colon cancer cells. 1922 Oct 16

Considerable progress has been made in the treatment of colon cancer from the era when 5-fluorouracil was the only effective agent for this disease. In addition to new chemotherapeutic agents, such as oxaliplatin, irinotecan, and capecitabine, the advent of biologic agents has contributed considerably to the treatment of colon cancer and has improved outcomes. An increased understanding of cancer at the molecular and genetic level has allowed for the development of therapeutics that target the multiple pathways essential to malignant behavior. While currently approved biotherapy in advanced colon cancer is limited to monoclonal antibodies against VEGF and EGFR, many more biologics targeting different pathways of oncogenesis are in development. There is also great interest in combining biotherapy not only with chemotherapy, but also with other biologics. Using rational combination biotherapy could overcome mechanisms of cancer cell resistance and result in synergistic activity. We review the various molecular targets of biologic therapy in colon cancer, discuss the rationale for their use as single agents and in combination, and present clinical evidence demonstrating their efficacy.
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PMID:Rationale for combining biotherapy in the treatment of advanced colon cancer. 1925 92

Neuropilins are membrane proteins that mediate effects on tumor cells directly and indirectly by affecting angiogenesis. Recent findings indicate that neuropilin 1 (NRP1) and the associated tyrosine kinase vascular endothelial growth factor receptor 2 (VEGFR2) play a regulatory role in developmental angiogenesis as well as in tumor angiogenesis. NRP1 and VEGFR2 might play a role in colon carcinogenesis and development of metastases. The significance of NRP1 expression in colon cancer seems to be controversial. Therefore, we aimed to distinguish between different expression patterns of signalling cascades in human colon carcinoma cell lines in order to analyze the role of NRP1 in tumorigenesis. We analyzed the biological significance of NRP1 in respect to VEGFR, EGFR, neuropilin and their ligands by RT-PCR and western blot with functional knock-out of NRP1 in different colon adenocarcinoma cell lines. There was no expression of VEGFR2 in tumor cell lines. There were cells that expressed: i) only NRP1 (HT-29, LS174T), ii) NRP2 (Colo320) or iii) both (SW480, LoVo). Cells without NRP1 expression strongly expressed EGFR but only when NRP2 was co-expressed. Inhibition of NRP1 expression by RNA interference did not alter growth characteristics in soft agar experiments. Furthermore, there were no differences in intracellular signalling pathways (ERK1/2 or AKT) in NRP1 inhibited cells. In ex vivo transfer experiments animals with tumors from siRNA-NRP1 transfected cells showed no significant inhibition of tumor growth compared to siRNA control. In conclusion, our results question the role of NRP1 function in VEGFR2 negative colon adenocarcinoma cells. NRP1 seems to have no detectable effect on proliferation or migration nor does it induce any changes in intracellular signalling pathways without the expression of VEGFR2. According to our data, further studies are needed to analyze the therapeutic relevance of NRP1 inhibition in vivo.
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PMID:No functional and transductional significance of specific neuropilin 1 siRNA inhibition in colon carcinoma cell lines lacking VEGF receptor 2. 1936 Feb 89

Tyrosine kinase inhibitors (TKI) or monoclonal antibodies targeting EGFR, HER2 or VEGFR receptors have demonstrated substantial clinical benefit in patients with advanced breast cancer, colon cancer, head and neck cancer, non-small cell lung cancer, and renal cell carcinoma. Nevertheless, these drugs have some target related adverse effects, particularly cardiovascular toxicities. We report here the case of a patient included in a phase I trial of a new compound, a tyrosine kinase inhibitor targeting HER1, HER2, HER4 and VEGFR2. The patient developed during this treatment an acute and transient left ventricular systolic dysfunction. Careful management of this adverse effect allowed the patient to continue therapy and to achieve a major partial response.
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PMID:Acute left ventricular dysfunction induced by a panHER and VEGFR tyrosine kinase inhibitor in a phase I trial. 1939

Novel gene expression profiles and cellular functions modulated in Caco-2 cells in response to the dietary polyphenol, ellagic acid (EA), and its colonic metabolites, urolithin-A (3,8-dihydroxy-6H-dibenzo[b,d] pyran-6-one) and urolithin-B (3-hydroxy-6H-dibenzo[b,d] pyran-6-one) have been identified. Exposure of cells to EA and urolithins arrested cell growth at the S- and G(2)/M-phases. Transcriptional profiling using microarray and functional analysis revealed changes in the expression levels of MAPK signalling genes such as, growth factor receptors (FGFR2, EGFR), oncogenes (K-Ras, c-Myc), and tumour suppressors (DUSP6, Fos) and of genes involved in cell cycle (CCNB1, CCNB1IP1). Results suggest that EA and urolithin-A and -B, at concentrations achievable in the lumen from the diet, might contribute to colon cancer prevention by modulating the expression of multiple genes in epithelial cells lining the colon. Some of these genes are involved in key cellular processes associated with cancer development and are currently being investigated as potential chemopreventive targets.
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PMID:Gene expression, cell cycle arrest and MAPK signalling regulation in Caco-2 cells exposed to ellagic acid and its metabolites, urolithins. 1943 80

Aging is associated with increased incidence of colon cancers. It is also becoming evident that cancer stem cells (CSC) play a vital role in the pathogenesis and prognosis of colon cancer. Recently, we reported the presence of colon cancer stem-like cells in macroscopically normal mucosa in patients with adenomatous polyps and that they increase with aging, suggesting that aging may predispose the colon to carcinogenesis. In the current study we have examined the combined effects of aging and carcinogen exposure on the status of colon CSCs in an experimental model. We used young (4-6 months) and aged (22-24 months) rats and exposed them to the carcinogen, dimethylhydroxide (DMH). We investigated the expression of colon cancer stem cell markers, CD44, CD166, EpCam, and ALDH1 as well as EGFR expression in normal colonic crypt epithelium following carcinogen treatment. Our results demonstrate that aging per se or carcinogen treatment alone causes an increase in the number of colon cancer stems cells, as evidenced by increased immunoreactive-CSC-markers positive cells in the colonic mucosa. In aged rats, carcinogen exposure results in a more pronounced increase in colon cancer stem cells. Our study shows that in aging colon the effects of carcinogens are more pronounced, and an increase in colon CSCs is one of the earliest changes preceding tumor development. Moreover, the current investigation of the use of a panel of immunohistochemical markers of colon CSC can potentially serve as a prognostic marker during screening for colon cancer.
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PMID:Combination of aging and dimethylhydrazine treatment causes an increase in cancer-stem cell population of rat colonic crypts. 1946 5

Cetuximab, an anti-EGFR human/mouse chimeric antibody, has just been approved in Japan for patients with EGFR positive unresectable or recurrent colorectal cancer, as monotherapy or in combination with irinotecan. We reported two cases of unresectable or recurrent colorectal cancer effectively treated by cetuximab after the progression of the prior chemotherapy. Case 1: A51-year-old male suffered from sigmoid colon cancer with synchronous liver metastases. He received cetuximab plus irinotecan combination therapy in the third-line setting. Amonth after the initiation of the chemotherapy, abdominal CT showed tumor shrinkage of liver metastases. Case 2: A57-year-old female suffered from sigmoid colon cancer with metachronous liver, ovarian metastases, ascites and pleural effusion. Her performance status(PS)according to ECOG performance scale was 1, and she complained of dyspnea on exertion. She received cetuximab monotherapy in the fourth-line setting. Five weeks after initiation of chemotherapy, her chest, abdominal and pelvic CT showed tumor shrinkage of the liver metastases and the reduction of both ascites and pleural effusion, together with resolution of her dyspnea on exertion. Before cetuximab administration, we investigated KRAS status on cancer tissue previously resected in the above 2 cases, which showed KRAS wild-type. Cetuximab could be effective for KRAS wild-type colorectal cancer, as well as the previous reports from Western countries.
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PMID:[Two cases of KRAS wild-type unresectable or recurrent colorectal cancer effectively treated by cetuximab after progression of prior chemotherapy]. 1954 25


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