Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The three interferon-alpha2 (IFN-alpha2) sequences identified to date differ from each other in just two nucleotide positions, both of which result in changes in amino acids. Thus, the mature IFN-alpha2a protein product is characterized by a lysine residue at position 23 (AAA) and a histidine at position 34 (CAA), IFN-alpha2b has an arginine at position 23 (AGA) and histidine at position 34 (CAT), and IFN-alpha2c has arginine residues at both positions 23 (AGA) and 34 (CGT). These nucleotide variations in the DNA sequence can be distinguished by selective restriction enzyme analysis. We studied the distributions of the three IFN-alpha2 variants by analyzing chromosomal DNA from 103 Japanese volunteers and 33 patients with hematologic disorders. Fragments of 238 bp and 617 bp of the IFN-alpha2 gene containing codons 23 and 34 were amplified by PCR using specific primers, and the PCR products were analyzed with specific restriction nucleases to identify the IFN-alpha2 variant sequences. Only IFN-alpha2b gene was detected in normal volunteers, and no IFN-alpha2a gene was detected in Japanese subjects. However, IFN-alpha2c was detected in 4 of 33 (12.1%) patients with leukemia.
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PMID:Determination of interferon-alpha2 allele composition in the genomic DNA from healthy volunteers and leukemic patients in Japan. 908 37

From 5% to 20% of patients with agnogenic myeloid metaplasia (AMM) will evolve into a terminal leukemic phase; N-RAS gene mutations are the most common gene abnormalities detected in patients with leukemia. The present study was designed to see if N-RAS gene mutations are associated with the leukemic transformation in AMM. Over a 9 year period, in a single institution, 43 patients with AMM were studied. Of these, ten patients were found to be in leukemic phase. The results showed that none of the patients in chronic phase (40 patients) had N-RAS gene mutations, while two patients in leukemic phase showed this gene mutation. One patient was found to have a codon 12 mutation with arginine substituting for glycine (GGT-->CGT); the other was a codon 12 mutation with glutamine substituting for glycine (GGT-->GAT). The present study suggests that N-RAS mutations are rare events in the chronic phase of AMM, and are only occasionally found when patients have evolved into leukemic transformation. Further studies to search for other gene abnormalities in AMM may be warranted.
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PMID:N-RAS oncogene mutations in patients with agnogenic myeloid metaplasia in leukemic transformation. 968 Jan 15

Leukemia, a form of haematological malignancy, is a multi-stage disease and a wide range of diverse genes has been speculated to correlate with its initiation and development. Ras has been speculated to be an initiating gene for haematological malignancy, but more investigation will be needed to determine the genes associated with the progression of the disease. 7,12-dimethylbenz(a)anthracene (DMBA)-induced rat leukemia provides a good tool for research into various stages of the disease. The entire coding regions of p53 and ras genes were examined for mutations in the present study. In this experiment, we used fluorescence-labeled polymerase chain reaction single-stranded conformation polymorphism analysis (PCR-SSCP) and direct sequencing to detect mutations of both genes on rat erythroleukemia. Fifteen out of 18 (83.3%) rat leukemias were found to have N-ras codon 61 mutation, consistent with previous results. The result of direct sequencing showed a single base substitution (CAA to CTA), resulting in an amino-acid change from Gln to Leu. No mutations were found in H-ras, K-ras or codon 12 of N-ras. The incidence of p53 gene mutation was 16.6% (3/18) in rat leukemia at late-stage. In the present study, mutation of the p53 gene was detected in three DMBA-induced leukemias as follows: a single-base substitution (CAT to CGT) at codon 177 (exon 5), resulting in an amino-acid change from Arg to Leu, a CGG to CTG/CGG changed at codon 211 (exon 6) resulting in an amino-acid change from His to Arg/His, and a GGG to TGG at codon 242 (exon 6) resulting in an amino-acid change from Gly to Trp, respectively. Thus, mutations of p53 gene do not seem to respond to the carcinogenesis of the DMBA-induced leukemia, in contrast to mutation of the N-ras oncogene, and may possibly be involved in the progress of multi-stage leukemogenesis.
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PMID:Incidence of p53 and ras gene mutations in DMBA-induced rat leukemias. 1238 83