Promoter methylation

DiziK M, CHRISTMAN J K andwAiNFAN E (1991) Alterations in expression and methylation of specific genes in livers of rats fed a cancer promoting methyl-deficient diet . Carcinogenesis, 12, 1307-12. 

Chen, JT, YW Cheng, MC Chou et al. 2003. The correlation between aberrant connexin 43 mRNA expression induced by promoter methylation and nodal micrometastasis in non-small cell lung cancer. Clin Cancer Res 9 4200-4204. 

Mitchell CP, Chen Y, Kundakovic M, Costa E, Grayson DR. 2005. Histone deacetylase inhibitors decrase reehn promoter methylation in vitro. J Neuochem 93 483-92. 

These findings suggest that dopamine deficiencies arising from MB-COMT promoter hypomethylation (i.e., increased expression) may influence promoter methylation and expression of RELN, DRD2, DRDl, and potentially other genes via coordinated epigenetic events that may aggravate disease symptoms (see Fig. 9.1). 

Despite our studies that have uncovered some epigenetic aberrations caused by promoter methylation changes in SCZ and BD, several other interacting genes... 

Although the standard MSP is an appropriate approach for promoter methylation status screening, our results clearly showed that subsequent evaluation of the differential promoter methylation level should be conducted by quantitative MSP (qMSP) to quantify the degree of these alterations to make clear correlations to the severity of the psychiatric disorders (H.M. Abdolmaleky and S. Thiagalingam, unpublished). In addition, it could be further validated using a complementary quantitative method such as immunoprecipitation (IP) of the methylated DNA to confirm the results of the qMSP (34). 

Dennis, K. E., and Levitt, P. (2005) Regional expression of brain derived neurotrophic factor (BDNF) is correlated with dynamic patterns of promoter methylation in the developing mouse forebrain. Brain Res. Mol. Brain Res. 140, 1-9. 

Rothem, L., Stark, M., Kaufman, Y., Mayo, L., and Assaraf, Y.G. (2004) Reduced folate carrier gene silencing in multiple antifolate-resistant tumor cell lines is due to a simultaneous loss of function of multiple transcription factors but not promoter methylation. Journal of Biological Chemistry. 279, 374-384. 

It was found that a nickel-activated carbon catalyst was effective for vapor phase carbonylation of dimethyl ether and methyl acetate under pressurized conditions in the presence of an iodide promoter. Methyl acetate was formed from dimethyl ether with a yield of 34% and a selectivity of 80% at 250 C and 40 atm, while acetic anhydride was synthesized from methyl acetate with a yield of 12% and a selectivity of 64% at 250 C and 51 atm. In both reactions, high pressure and high CO partial pressure favored the formation of the desired product. In spite of the reaction occurring under water-free conditions, a fairly large amount of acetic acid was formed in the carbonylation of methyl acetate. The route of acetic acid formation is discussed. A molybdenum-activated carbon catalyst was found to catalyze the carbonylation of dimethyl ether and methyl acetate. 

Soria JC, Lee HY, Lee JI et al. Laek of PTEN expression in non-small cell lung caneer eould be related to promoter methylation. Clin Cancer Res 2002 8 1178-1184. 

Loss of tumor suppressor gene function can occur through mutation but also promoter methylation, which silences genes. 

If ethylene is present during the carbonylation of methanol catalyzed by IrCl4, once again with Mel as promoter, methyl propionate is formed.416 The reaction depends on the presence of iridium hydride species in solution, and a rhodium analogue of the reaction exists. The full details of the mechanism are not known but the basic steps are shown in Scheme 34. The intermediates are all believed to be complexes of iridium(IIl). 

A complex of formula cis-MeC(0)Mn(C0)4(AlBr3) resulting from the AlBrj-promoted methyl migration in MeMn(CO)s has been isolated and studiedby crystal X-ray diffraction methods. This adduct has the molecular structure E, with a five-membered metallacycle, whereby both manganese(I) and aluminum(III) acquire their typical coordination numbers of six and four, respectively. 

Nagarajan RP, Hogart AR, Gwye Y, Martin MR, LaSalle JM (2006) Reduced MeCP2 expression is frequent in autism frontal cortex and correlates with aberrant MECP2 promoter methylation. Epigenetics l el-ll. 

While four domains of methionine synthase bind reaction components (HCY, SAM, cobalamin, and methylfolate), the fifth domain, known as the Cap domain, hovers above cobalamin while it is in its readily oxidized Cob(I) state, limiting access of reactive oxygen species or electrophilic substances. As such, the Cap domain restricts inactivation of methionine synthase and consequently promotes methylation over transsulfuration. In rt-PCR smdies using RNA from cultured human neuroblastoma cells, we found that the Cap sequence, corresponding to... 

Simpkins SB, Bocker T, Swisher EM, et al. MLHl promoter methylation and gene silencing is the primary cause of microsatellite instability in sporadic endometrial cancers. Hum Mol Genet. 1999 8 661-666. 

Buttin BM, Powell MA, Mutch DG, et al. Increased risk for hereditary nonpolyposis colorectal cancer-associated synchronous and metachronous malignancies in patients with microsatellite instability-positive endometrial carcinoma lacking MLHl promoter methylation. Clin Cancer Res. 2004 10 481-490. 

SCHEME 3 Catalytic cycle for Lil-promoted methyl acetate carbonylation. 

MGMT promoter methylation and field defect in sporadic colorectal cancer. J. Natl. Cancer Inst., 97, 1330-1338. 

Various approaches for the O-methylation of coals have appeared. These include reaction with diazomethane (7) and, more recently, base-promoted methylation in which coal is first neutralized with an aqueous tetrahydrofuran (THF) base solution followed by reaction with methyl iodide (8-10) or methyl p-toluenesulfonate (II). Instead, we opted to O-methylate PSOC 1197 with 13,14C double-labeled dimethyl sulfate at various pH values. This approach was taken to evaluate the distribution of acidic OH sites and to determine an acceptable set of O-methylation conditions. Briefly, the coal was neu-... 

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