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)

A novel mRNA isoform encoding the cell surface metalloproteinase meprin beta is expressed in mouse teratocarcinoma cells and in a variety of cultured human cancer cells. In both mouse and human cells, the cancer cell-specific mRNA isoform, referred to as beta', has an extended 5' UTR as compared to the meprin beta mRNA isoform expressed in normal kidney and intestinal epithelium. The work herein aimed to determine the molecular mechanisms for the expression of meprin beta and beta' in normal and cancer cells, respectively. Analysis of the 5' end of the mouse meprin beta gene revealed that the unique sequences in the beta and beta' mRNA isoforms are encoded by separate exons that are alternately spliced, and transcribed from independent promoters. By contrast, the human meprin beta and beta' mRNAs have identical sequences except for 87 additional bases in the 5' UTR sequence of beta', indicating that a single, mixed usage promoter directs expression of the isoforms. The region upstream of the human meprin beta' transcription start site contained elements with homology to the promoters of intestine-specific genes, interspersed with AP-1 and PEA3 elements; the latter were essential to meprin beta' promoter activity in cancer cells. Phorbol myristal acetate increased meprin beta' mRNA levels in cultured human colon cancer cells, providing further evidence that AP-1/PEA3 sites are actively involved in meprin beta' expression.
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PMID:Meprin B: transcriptional and posttranscriptional regulation of the meprin beta metalloproteinase subunit in human and mouse cancer cells. 1019 Feb 76

A novel mRNA isoform (meprin beta') of the cell-surface protease subunit meprin beta was previously identified in human colon cancer cells. The study reported here revealed that this mRNA isoform was identical within the protein coding region and at the 3' end to the beta isoform of normal intestine but that it contained an extended 5' untranslated region. Meprin beta' mRNA was expressed in the human breast cancer cell lines MCF-7 and SK-BR-3, in the human osteosarcoma cell line U2 Os, and in the human pancreatic cancer cell line BxPC-3. Meprin beta mRNA, but not beta' mRNA, was expressed in human fetal kidney cells. We cloned and sequenced genomic DNA encoding portions of the promoter region of the meprin beta gene. The unique sequences present in the beta' mRNA were present in the human genomic DNA immediately upstream of the transcription start site for the beta mRNA. The human meprin promoter sequence was searched for potential transcription-factor binding sites, and putative activator protein-1, polyoma enhancer activator 3 (PEA3), CCAAT enhancer-binding protein beta, and estrogen-receptor binding sites were identified along with binding sites for the intestine-specific cdx-2 transcription factor. The activity of meprin promoter/luciferase reporter gene constructs transfected into U2 Os cells was highest with constructs containing 83 and 639 bp of promoter DNA. These regions of the promoter each contain a putative PEA3 element. Treatment of the human colon adenocarcinoma cell line HT29-18C1 with 50 or 100 ng/mL phorbol myristal acetate for 8 h increased meprin beta' mRNA levels. Likewise, U2 Os cells transfected with the -639/luciferase or -1800/luciferase constructs showed a phorbol myristal acetate-inducible increase in reporter gene activity, indicating that the PEA3 element within the -639 construct or other elements further upstream respond to phorbol ester.
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PMID:Expression and regulation of the meprin beta gene in human cancer cells. 1041 Nov 43

Familial adenomatous polyposis (FAP) is an inherited condition secondary to germline mutations in the APC gene, thus resulting in the formation of hundreds of colonic adenomas that eventually progress into colon cancer. Surgical removal of the colon remains the only treatment option to avoid malignancy, as long-term exposure to chemopreventive agents such as sulindac (a non-steroidal anti-inflammatory drug) and silymarin (phytoestrogen) is not feasible. Here, we have developed a multistage silicon-based drug delivery platform for sulindac and silymarin that preferentially interacts with colon cancer cells as opposed to normal intestinal mucosa. Preferential binding and internalization of these drugs into colon cancer cells was obtained using a targeting strategy against the protein meprin A, which we demonstrate is overexpressed in human colon cancer cells and in the small intestine of Apc(Min/+) mice. We propose that this delivery system could potentially be used to reduce drug-induced side effects in FAP patients, thus enabling long-term prevention of adenoma formation.
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PMID:Multistage vector delivery of sulindac and silymarin for prevention of colon cancer. 2651 52