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)

Iron deficiency is the world's most common nutritional deficiency and is associated with developmental delay, impaired behavior, diminished intellectual performance, and decreased resistance to infection. In premenopausal women, the most common causes of iron deficiency anemia are menstrual blood loss and pregnancy. In men and postmenopausal women, the most common causes of iron deficiency anemia are gastrointestinal blood loss and malabsorption. Hemoglobin concentration can be used to screen for iron deficiency, whereas serum ferritin concentration can be used to confirm iron deficiency. However, the serum ferritin concentration may be elevated in patients with infectious, inflammatory, and neoplastic conditions. Other tests may be needed, such as erythrocyte zinc protoporphyrin concentration, transferrin concentration, serum iron concentration, and transferrin saturation. The cause of iron deficiency must be identified. If the patient is male, postmenopausal female, or has risk factors for blood loss, then the patient should be evaluated for sources of blood loss, especially gastrointestinal (eg, colon cancer). Several studies have examined the relationship between iron deficiency and hair loss. Almost all have addressed women exclusively and have focused on noncicatricial hair loss. Some suggest that iron deficiency may be related to alopecia areata, androgenetic alopecia, telogen effluvium, and diffuse hair loss, while others do not. Currently, there is insufficient evidence to recommend universal screening for iron deficiency in patients with hair loss. In addition, there is insufficient evidence to recommend giving iron supplementation therapy to patients with hair loss and iron deficiency in the absence of iron deficiency anemia. The decision to do either should be based on clinical judgment. It is our practice at the Cleveland Clinic Foundation to screen male and female patients with both cicatricial and noncicatricial hair loss for iron deficiency. Although this practice is not evidence based per se, we believe that treatment for hair loss is enhanced when iron deficiency, with or without anemia, is treated. Iron deficiency anemia should be treated. Treating iron deficiency without anemia is controversial. Treatment of nutritional iron deficiency anemia includes adequate dietary intake and oral iron supplementation. Excessive iron supplementation can cause iron overload and should be avoided, especially in high-risk patients such as those with hereditary hemochromatosis. Patients who do not respond to iron replacement therapy should undergo additional testing to identify other underlying causes of iron deficiency anemia.
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PMID:The diagnosis and treatment of iron deficiency and its potential relationship to hair loss. 1731 91

In spite of the paramount importance of zinc in biology, dynamic aspects of cellular zinc metabolism remain poorly defined at the molecular level. Investigations with human colon cancer (HT-29) cells establish a total cellular zinc concentration of 264 microM. Remarkably, about 10% of the potential high-affinity zinc-binding sites are not occupied by zinc, resulting in a surplus of 28 muM ligands (average Kd(c) = 83 pM) that ascertain cellular zinc-buffering capacity and maintain the "free" zinc concentration in proliferating cells at picomolar levels (784 pM, pZn = 9.1). This zinc-buffering capacity allows zinc to fluctuate only with relatively small amplitudes (DeltapZn = 0.3; below 1 nM) without significantly perturbing physiological pZn. Thus, the "free" zinc concentrations in resting and differentiated HT-29 cells are 614 pM and 1.25 nM, respectively. The calculation of these "free" zinc concentrations is based on measurements at different concentrations of the fluorogenic zinc-chelating agent and extrapolation to a zero concentration of the agent. It depends on the state of the cell, its buffering capacity, and the zinc dissociation constant of the chelating agent. Zinc induction of thionein (apometallothionein) ensures a surplus of unbound ligands, increases zinc-buffering capacity and the availability of zinc (DeltapZn = 0.8), but preserves the zinc-buffering capacity of the unoccupied high-affinity zinc-binding sites, perhaps for crucial physiological functions. Jointly, metallothionein and thionein function as the major zinc buffer under conditions of increased cellular zinc.
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PMID:Zinc-buffering capacity of a eukaryotic cell at physiological pZn. 1692 57

FTase inhibitors constitute a new class of potential cancer therapeutics, especially in colorectal cancer where K-ras-selective mutations exist and have a role in tumorigenesis. The synthesis and biological evaluation of two nonpeptidic molecules (13 and 16) designed on the basis of a zinc chelator imidazole linked to two aromatic fragments able to fit in the "exit groove" and in the "A2 binding site" of FTase are described. These molecules are characterized respectively by a flexible phenylmethyl chain and a more constrained scaffold so as to evaluate their respective influences on site recognition. They have been evaluated in vitro and in vivo against human colon cancer cell lines and 13 not only inhibited tumor growth but also showed no toxic effects at the dose used.
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PMID:In vitro and in vivo evaluation of two rational-designed nonpeptidic farnesyltransferase inhibitors on HT29 human colon cancer cell lines. 1692 12

The ecotropic viral integration site 1 (EVI1) gene was identified as a common locus of retroviral integration in myeloid tumors found in mice. EVI1 gene is highly conserved through evolution and human gene EVI1 on chromosome 3q26 encodes zinc fingers-containing transcription factor. EVI1 is expressed in nonhematopoietic tissues but not in normal blood or bone marrow. EVI1 was detected in hematopoietic cells in retrovirus-induced myeloid leukemias in mice and several reports documented EVI1 expression in human myelodysplastic syndromes and other hematologic malignancies without 3q26 translocations. EVI1 is abnormally expressed in human myeloid leukemias that are associated with the t(3;3)(q21;q26), t(3;21)(q26;q22), inv(3)(q21q26) and other chromosomal rearrangements. EVI1 is overexpressed in some ovarian cancers and human colon cancer cell lines and may play a role in the initiation and/or progression of solid tumors, as well as hematopoietic malignancies. EVI1 is a transcriptional repressor which inhibits transforming growth factor beta (TGFbeta) family signalling by binding signal transducers (Smad proteins) and recruiting transcriptional corepressors. TGFbeta is an important regulator of proliferation, differentiation, apoptosis and migration of cells. EVI1 inhibits TGFbeta-mediated apoptosis. Knockdown of EVI1 function by small interference RNA increases the sensitivity of malignant cells to TGFbeta-mediated or other inducer-mediated apoptosis. Overexpressed EVI-1 blocks granulocyte and erythroid differentiation and possess the ability of growth promotion in some types of cells. EVI1 functions in some cases as a transcriptional activator which stimulates for example GATA2 and GATA3 promoters. The study of EVI1 target genes will help to clear the mechanism by which EVI1 upregulates cell proliferation, impairs cell differentiation, and induces cell transformation.
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PMID:[EVI1 and its role in myelodysplastic syndrome, myeloid leukemia and other malignant diseases]. 1699 17

Alterations in tissue zinc levels have been documented in patients with gastrointestinal tract malignancies and more frequently, in those with colonic cancer. However, the precise role of tissue zinc in carcinogenesis is not well elucidated. This study, using a well-established colon cancer model in rats, was designed to investigate the relationship of tissue zinc to the carcinogenic process. The aim was to examine tissue zinc levels in the preneoplastic tissues and to study the changes that occur during transition of mucosa from normal to preneoplastic state. Six-week old rats were given a single dose subcutaneous injection of azoxymethane (AOM) (30mg/kg body weight) and sacrificed after 1, 2, 5, and 9 months of the treatment. Plasma zinc levels showed a significant decrease (p<0.05) at 9 months compared with controls. Tissue zinc levels showed a significant decrease in the large intestine at 1 and 2 months (p<0.05) and at 5 and 9 months (p<0.01), in the small intestine at 2, 5, and 9 months (p<0.05), and in the stomach at 5 and 9 months (p<0.05). The maximum percent decrease (45%) in tissue zinc was observed in the large intestine at 9 months. Tissue copper zinc super oxide dismutase (CuZnSOD) activity was assessed in the body of the stomach, small intestine, and large intestine and compared with the control group. There was a significant fall in CuZnSOD levels in the small intestine at 9 months (p<0.05) and in the large intestine at 5 and 9 months (p<0.01). Two of these six rats showed histological evidence of precancerous lesions in the mucosa of the colon. This study suggests that the decrease in plasma zinc, tissue zinc and activity of CuZnSOD is associated with development of preneoplastic lesions in the colonic mucosa.
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PMID:Tissue zinc levels in precancerous tissue in the gastrointestinal tract of azoxymethane (AOM)-treated rats. 1803 1

Src kinase has been linked as a causative agent in the progression of a number of cancers including colon, breast, lung and melanoma. Src protein and activity levels are increased in colorectal cancer and liver metastases arising secondary to colon cancer. However, although Src protein is increased in colon cancer as early as the adenomatous polyp stage, a role for Src in carcinogenesis has not been established. We developed the c-SRC transgenic mouse in the C57BL/6 strain to address the issue of carcinogenesis in cells with high levels of Src expression. The transgene was constructed with the human c-SRC gene downstream of the mouse metallothionein promoter to create zinc inducible gene expression. In these C57BL/6 mice, Src protein was increased in a number of tissues both with and without zinc induction. No additional carcinogenic agent was administered. After 20 months, mice were assessed for tumor development in the liver and GI tract, as well as other organs. Of the mice with the transgene, 15% developed tumors in the liver while no tumors were detected in wild type C57BL/6 mice. A further study was conducted by crossing c-SRC C57BL/6 mice with p21 nullizygous mice to determine the effect of oncogene expression combined with inactivation of the tumor suppressor gene, p21. Addition of the c-SRC transgene to the p21-/- background increased tumor formation almost 3-fold, while it increased metastasis 6-fold. The data from our study show, for the first time, that Src kinase may play a role in carcinogenesis.
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PMID:Src kinase induces tumor formation in the c-SRC C57BL/6 mouse. 1835 44

About half of cancers sustain mutations in the TP53 gene, whereas the other half maintain a wild-type p53 (wtp53) but may compromise the p53 response because of other alterations. Homeodomain-interacting protein kinase-2 (HIPK2) is a positive regulator of p53 oncosuppressor function. Here, we show, by microarray analysis, that wtp53 lost the target gene activation following stable knockdown of HIPK2 (HIPK2i) in colon cancer cell line. Our data show that the stable knockdown of HIPK2 led to wtp53 misfolding, as detected by p53 immunoprecipitation with conformation-specific antibodies, and that p53 protein misfolding impaired p53 DNA binding and transcription of target genes. We present evidence that zinc supplementation to HIPK2i cells increased p53 reactivity to conformation-sensitive PAb1620 (wild-type conformation) antibody and restored p53 sequence-specific DNA binding in vivo and transcription of target genes in response to Adriamycin treatment. Finally, combination of zinc and Adriamycin suppressed tumor growth in vivo and activated misfolded p53 that induced its target genes in nude mice tumor xenografts derived from HIPK2i cells. Bioinformatics analysis of microarray data from colon cancer patients showed significant association of poor survival with low HIPK2 expression only in tumors expressing wtp53. These results show a critical role of HIPK2 in maintaining the transactivation activity of wtp53 and further suggest that low expression of HIPK2 may impair the p53 function in tumors harboring wtp53.
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PMID:Reversible dysfunction of wild-type p53 following homeodomain-interacting protein kinase-2 knockdown. 1848 53

Reaction of 4,4-biphenyl-disulfonyl chloride with aromatic/heterocyclic sulfonamides also incorporating a free amino group, such as 4-aminobenzenesulfonamide, 4-aminoethyl-benzenesulfonamide, 6-chloro-4-aminobenzene-1,3-disulfonamide or 5-amino-1,3,4-thiadiazole-2-sulfonamide afforded bis-sulfonamides which have been tested as inhibitors of the zinc enzyme carbonic anhydrase (CA, EC 4..2.1.1). The compounds were rather modest inhibitors of isozymes CA I and XII, but were more efficient as inhibitors of the cytosolic CA II and transmembrane, tumor-associated CA IX (inhibition constants in the range of 21-129 nM gainst hCA II, and 23-79 nM against hCA IX, respectively). The new bis-sulfonamides also showed inhibition of growth of several tumor cell lines (ex vivo), with GI(50) values in the range of 0.74-10.0 microg/mL against the human colon cancer cell line HCT116, the human lung cancer cell line H460 and the human breast cancer cell line MCF-7.
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PMID:Carbonic anhydrase inhibitors. Biphenylsulfonamides with inhibitory action towards the transmembrane, tumor-associated isozymes IX possess cytotoxic activity against human colon, lung and breast cancer cell lines. 1860 52

Zinc has been shown to have inhibitory effects on proliferation and metabolism of malignant colonocytes. Still, there is no information available concerning putative effects of zinc against motility and migration of colon cancer cells. Using fluorescence microscopy, immunoblotting and microflorimetry we show that treatment with zinc sulfate affected motility, invasiveness, cytoskeletal integrity and expression of selected markers (E-cadherin, catenin, vimentin, tubulin and actin) of invasive SW480 colon tumor cells. These results emphasize the possible multitudinous role of zinc in the process of colon cancer development and hint at the potential of this element in chemoprevention of advanced colorectal carcinoma.
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PMID:Zinc alters cytoskeletal integrity and migration in colon cancer cells. 1868 70

We previously described the novel zinc finger protein ZKSCAN3 as a new "driver" of colon cancer progression. To investigate the underlying mechanism and because the predicted structural features (tandem zinc fingers) are often present in transcription factors, we hypothesized that ZKSCAN3 regulates the expression of a gene(s) favoring tumor progression. We employed unbiased screening to identify a DNA binding motif and candidate downstream genes. Cyclic amplification and selection of targets using a random oligonucleotide library and ZKSCAN3 protein identified KRDGGG as the DNA recognition motif. In expression profiling, 204 genes were induced 2-29-fold, and 76 genes reduced 2-5-fold by ZKSCAN3. To enrich for direct targets, we eliminated genes under-represented (<3) for the ZKSCAN3 binding motif (identified by CAST-ing) in 2 kilobases of regulatory sequence. Up-regulated putative downstream targets included genes contributing to growth (c-Met-related tyrosine kinase (MST1R), MEK2; the guanine nucleotide exchanger RasGRP2, insulin-like growth factor-2, integrin beta 4), cell migration (MST1R), angiogenesis (vascular endothelial growth factor), and proteolysis (MMP26; cathepsin D; PRSS3 (protease serine 3)). We pursued integrin beta 4 (induced up to 6-fold) as a candidate target because it promotes breast cancer tumorigenicity and stimulates phosphatidyl 3-kinase implicated in colorectal cancer progression. ZKSCAN3 overexpression/silencing modulated integrin beta 4 expression, confirming the array analysis. Moreover, ZKSCAN3 bound to the integrin beta 4 promoter in vitro and in vivo, and the integrin beta 4-derived ZKSCAN3 motif fused upstream of a tk-Luc reporter conferred ZKSCAN3 sensitivity. Integrin beta 4 knockdown by short hairpin RNA countered ZKSCAN3-augmented anchorage-independent colony formation. We also demonstrate vascular endothelial growth factor as a direct ZKSCAN3 target. Thus, ZKSCAN3 regulates the expression of several genes favoring tumor progression including integrin beta 4.
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PMID:Unbiased screening for transcriptional targets of ZKSCAN3 identifies integrin beta 4 and vascular endothelial growth factor as downstream targets. 1894 Aug 3


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