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)

In the intestine, the vitamin D receptor is activated by 1alpha, 25-dihydroxyvitamin D3 [1,25(OH)2D3] to perform its function in calcium homeostasis, or it is activated by lithocholic acid when its levels are elevated after a meal. Both ligands transcriptionally up-regulate the mRNA of enzymes belonging to the CYP3A subfamily, increasing the metabolism of a variety of carcinogens, drugs, and hormones. Of the cytochrome P450 enzymes, the CYP3A subfamily is the most abundant in liver and intestine and has the widest range of substrate specificity. In addition to being a ligand for the vitamin D receptor, lithocholic acid is also a substrate for CYP3A enzymes. Lithocholic acid causes colon cancer; thus, decreasing lithocholic acid levels in the intestine by up-regulating CYP3A enzymes with 1,25(OH)2 D3 analogs may have therapeutic value in the prevention of colon cancer. We investigated the induction of CYP3A9 by 1,25(OH)2D3 and 19nor-1alpha,25-dihydroxyvitamin D2[19nor-1,25(OH)2 D2]. We observed the that latter analog, currently used to treat renal osteodystrophy, is more efficacious than 1,25(OH)2 D3 in inducing CYP3A9 in rat intestines. CYP3A9 mRNA was maximally elevated 5 to 7 h after a single dose of 1,25(OH)2 D3 to rats and then gradually returned to baseline. We performed promoter deletion analysis of the rat CYP3A9 promoter and identified one proximal vitamin D response element located at -119 to -133 from the transcriptional start site, which is responsible for a large part of the 1,25(OH)2D3 response, and two other vitamin D response elements located at -726 to -744 and at -754 to -776, which together are responsible for the increased sensitivity of CYP3A9 to 19nor-1,25(OH)2D2.
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PMID:19nor-1,25-dihydroxyvitamin D2 specifically induces CYP3A9 in rat intestine more strongly than 1,25-dihydroxyvitamin D3 in vivo and in vitro. 1648 1

Colorectal cancer is a significant cause of morbidity and mortality worldwide. The advances in early diagnosis and treatment have increasingly expanded the patient population surviving from colorectal cancer. Herein, we present a case of a patient with mediastinal ectopic parathyroid adenoma who has been followed up for postoperative colon cancer. The patient is a 59-year-old man with postoperative colon cancer and chronic renal failure in whom control positron emission tomography/computed tomography revealed multiple bone metastases. However, on methylene-diphosphonate bone scintigraphy, multiple involvement with increased uptake was associated with renal osteodystrophy/hyperparathyroidism; technetium-99m 2-methoxyisobutylisonitrile parathyroid scintigraphy was performed, which revealed mediastinal ectopic parathyroid adenoma. To the best of our knowledge, this is the first case report in the literature reporting the co-occurrence of colon cancer, chronic renal failure, and ectopic parathyroid adenoma.
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PMID:Mediastinal Ectopic Parathyroid Adenoma in a Patient Followed for Colon Cancer and Chronic Renal Failure: A Challenging Case. 3105 88