Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026764 (multiple myeloma)
 36,148 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mutation of the RAS oncogene was studied in ten patients with multiple myeloma, and the DNA from nude mouse tumors formed by cells obtained from tumorigenecity assays (in vivo selection assays) in these patients was analyzed by PCR and oligonucleotide hybridization. Mutations of the N-RAS oncogene were identified in two of three patients investigated by in vivo selection assay and in five of ten patients investigated by PCR analysis of DNA from myeloma cells. In the two former patients, mutation of the N-RAS oncogene was observed at the 61st codon. Of the five N-RAS mutant-positive patients investigated by the PCR analysis, one had a mutation at codon 12, two had mutations at codon 13, and two had mutations at codon 61. None of the patients had mutations of the K-RAS oncogene. These results suggest that the frequency of RAS gene mutation in multiple myeloma is higher than in other lymphoid malignancies such as acute lymphocytic leukemia, chronic lymphocytic leukemia, and malignant lymphoma. As the mutation was observed only at the N-RAS oncogene level, it is speculated that N-RAS oncogene activation might play an important role in the progression of multiple myeloma.
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PMID:A high frequency of N-RAS oncogene mutations in multiple myeloma. 142 Nov 73

We analysed genomic DNA from 30 patients with multiple myeloma (MM), searching for alterations in the p53 and RAS genes by a combination of polymerase chain reaction and single-strand conformation polymorphism techniques. Mutations in the p53 gene were observed in 20% (6 out of 30) of the patients, and were located in conserved sequence blocks within exons 5 and 7. These were single-nucleotide substitutions and consisted predominantly (4/6) of G:C to A:T transitions. Of the six patients with a mutated p53 gene, four were in the terminal phase of the disease. RAS gene mutations were found more frequently since they occurred in 47% (14 out of 30) of the patients. Mutations consisted of single-nucleotide substitutions, located in codons 12, 13 and 61 of either K- or N-RAS, to the exclusion of H-RAS. Moreover, one patient bore two simultaneous mutations, affecting simultaneously the K- and the N-RAS genes. RAS gene mutations were more frequently observed in patients with fulminating disease (10/15, 67%) than in patients with less aggressive forms of the disease (4/15, 26%). We also analysed genomic DNAs from 10 human myeloma cell lines, of which two bore mutations affecting codon 12 of the K-RAS gene, and one codon 12 of the N-RAS gene. The first two cell lines were obtained from freshly explanted tumor cells in which we observed identical mutations. Results presented here show that activating mutations in the RAS genes are, in MM, more frequent than those affecting the p53 gene and suggest that both events are related to terminal phases of the disease.
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PMID:p53 and RAS gene mutations in multiple myeloma. 146 58

The presence of RAS gene mutations in precancerous lesions suggests that they participate in the early stages of neoplastic development. Furthermore, neoplastic progression from monoclonal gammopathy of undetermined significance (MGUS) to overt multiple myeloma (MM) have been frequently observed. These observations prompted us to study the pathogenetic role of RAS genes in MM and related monoclonal gammopathies. DNA from 18 patients with monoclonal gamma-globulinemia including 12 MM were investigated for the presence of N- and K-RAS gene mutations by polymerase chain reaction (PCR)/oligonucleotide hybridization. Mutations involving codons 12, 13 or 61 of N-RAS gene were identified in 3 of the 12 MM patients, 1 of the solitary plasmacytoma patients and none of the 3 of the MGUS patients. In the case of plasmacytoma, RAS mutations were detected in his bone marrow specimens.
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PMID:RAS gene mutations in multiple myeloma and related monoclonal gammopathies. 192 Dec 61

Flow cytometry (FCM) is a useful method for clinical research of oncogene products since it can analyze proteins quantitatively which are located at cell surfaces or inside of cells. Oncogene products are now under study by FCM not only as tumor markers but also as functioning proteins in carcinogenesis. The examples of oncogene products analyzed by FCM are ras, myc, p53, myb and fos; those of cell-proliferation-related proteins are Ki-67, PCNA and DNA polymerase alpha. In some diseases the relationship between these proteins and disease classification, stage, pathophysiology, or prognosis have been clarified. Using dual color FCM of H-ras p21 and DNA, we analyzed the expression of H-ras p21 in human multiple myeloma and leukemias and found that H-ras p21 levels in multiple myeloma strongly correlated to the prognosis of patients (p = 0.03). When AML cells were stimulated by adding G-CSF, it was found that many cells proliferated but some were dying. The percentage of dying cells was small in one AML case whose myeloblasts showed increased expression of H-ras p21 by G-CSF stimulation. Together with other papers reviewed, it is conceivable that H-ras p21 expression is related to cell proliferation and inhibition of cell autolysis. Thus FCM is useful in the classification of the role of oncogene products in carcinogenesis in clinical cases.
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PMID:[Application of flow cytometry to the study of hematologic disorders: analysis of oncogene products]. 214 49

DNA from 161 patients with various forms of hematologic malignancies were investigated for mutations in exons 1 and 2 of the N-RAS, K-RAS and Ha-RAS gene by direct sequencing of DNA amplified in vitro by the polymerase chain reaction. Mutations involving either codons 11, 12, or 13 of the N-RAS gene were identified in 18 of the 161 patients. The relative frequencies of N-RAS gene mutations in these hematologic disorders was as follows: acute myelogenous leukemia (AML), 15%; acute lymphoblastic leukemia (ALL), 14%; myelodysplastic syndromes, 24%; and myeloid and lymphoid blast crisis of chronic myelogenous leukemia (CML), 3%. No correlation was observed between the presence of mutations and cytologic features or immunophenotype of these malignancies. Mutations involving codons 12 or 13 were equally prevalent, with a glycine to aspartic acid substitution being the most frequently encountered change. A single T-ALL case had a codon 11 mutation resulting in substitution of alanine with threonine. We failed to find mutations in exons 1 and 2 of the K-RAS or Ha-RAS genes in any case except a single AML with a mutation in codon 61 of the K-RAS gene. Also, no mutations were identified in chronic phase of CML, chronic lymphocytic leukemia. Ph1 positive ALL, non-Hodgkin's lymphoma, Hodgkin's disease, or multiple myeloma. These results indicate that RAS mutations, especially those involving exon 1 of the N-RAS gene, are frequent only in a subset of hematologic malignancies.
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PMID:The pattern of mutational involvement of RAS genes in human hematologic malignancies determined by DNA amplification and direct sequencing. 218 88

Plasma cell myeloma is a more complex neoplasm than suggested by the relative uniformity of its dominant plasma cells, which represent the terminal stage of normal B-cell differentiation. Phenotypic, molecular, and cellular genetic data favor the presence of a myeloma stem cell early in hematopoietic development so that, as in chronic myelogenous leukemia (CML), a far distance exists between the primordial malignant cell that was the target of malignant transformation and the dominant clinical phenotype. Traces of pre-B, myeloid, and T cells are coexpressed with the mature B-cell phenotype, an occurrence unknown in normal B-cell differentiation. Analogous to CML, disease progression is marked by disease dedifferentiation, occasionally with cessation of myeloma protein production and development instead of extramedullary lymphomalike features with high LDH or myelodysplasia/acute myelogenous leukemia (AML) syndromes. The prognostic importance of serum LDH levels even in newly diagnosed myeloma suggests the early presence of tumor cells with "LDH phenotype," which, as a result of drug resistance and proliferative advantage, expand preferentially during disease progression. Further characterization of these cells may provide important clues about the ontogeny of multiple myeloma. Myeloma cells express many receptors for different biological signals that might be exploitable for therapy with immunotoxins or radioisotopes. Plasma cells and their precursors also produce a variety of cytokines, some of which have putatively autostimulatory functions (eg, IL-1, IL-5, IL-6) and/or are related to disease manifestations (eg, IL-1 and TNF-beta as OAF). The wealth of cellular expression by plasma cells provides clues for understanding the mechanisms of gene activation and the nature of abnormal growth and differentiation. The accuracy of prognostically relevant staging systems has been refined with the use of new quantitative parameters that reflect tumor mass (ie, serum B2M levels) and biology. Further studies of cellular and molecular biology (ie, CAL-LA, H-ras) may reveal those tumor cell features that define clinical entities, response to therapy, and long-term prognosis. The lack of a major advance in prognosis despite the use of more drugs and more intensive regimens justifies the continued use of standard melphalan-prednisone for patients with a highly favorable prognosis, for the very aged, and for those with a short life expectancy due to other major medical problems. However, a radical departure from standard practice is required to improve the prognosis for younger patients with poor risk features.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Plasma cell myeloma--new biological insights and advances in therapy. 246 90

Flow cytometry (FCM) of oncogene products which opens new avenues of cell biological investigation of human neoplasia is being reviewed. Using H-ras p21/DNA dual FCM, patients with DNA-aneuploid multiple myeloma (MM) were examined. The patients whose MM cells expressed high level of H-ras p21 had poor prognosis. Specificity of this assay was appraised extensively. It is not likely that H-ras p21 expressed in MM is of oncogenic form since point mutation of H-ras gene was not reported in B cell chronic lymphocytic leukemia which is closely located to MM in B lymphocyte differentiation lineage. High expression of H-ras p21 in MM seems to be related to cell proliferation and/or differentiation. H-ras p21/DNA dual FCM is applicable to analyse the pathophysiology of tumor cells. FCM analyses of other oncogene products and proteins related to cell proliferation, c-myc, p53 and Ki-67, were also described. Multiparameter FCM analysis is quite suited to examine expression of these proteins in situ.
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PMID:[Flow cytometric analysis of oncogene products]. 266 53

Bone marrow plasma cell proliferative activity has been evaluated in a large series of multiple myeloma (MM) patients. This kinetic parameter has been shown to be a useful tool for patient management, and contributes to a correct diagnosis and a selection of high-risk patients who can be offered high-dose chemotherapy. The role of ras oncogenes has been evaluated in the pathogenesis of MM. A point-mutated and activated H-ras oncogene, introduced in a human lymphoblastoid cell line, was able to induce neoplastic transformation and differentiation to plasma cell. Indeed, mutated alleles of ras genes have been detected in a high percentage of myeloma patients in relapse phase. Phenotypical and functional studies have been carried out in T-lymphocyte subsets and an impaired cellular immunity has been detected. Such an impairment was related to the disease status: marked alterations were detected in relapse phase, whereas a partial recovery was observed during remission phase.
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PMID:Advances in biology of multiple myeloma: cell kinetics, molecular biology and immunology. 269 92

Correlated analysis of the H-ras oncogenes product (p21) and of nuclear DNA content was performed by flow cytometry (FCM) in patients with DNA-aneuploid multiple myeloma (MM). Bone marrow cells from normal donors and MM patients in remission served as controls. Seventy-four percent of 23 patients with active MM had higher p21 fluorescence in aneuploid tumor cells than were observed in normal donor or myeloma remission bone marrows; 39% of the 23 patients also showed high H-ras p21 expression in diploid cells. There was an inverse relationship between p21 levels and the presence of trisomy 11; especially high p21 levels were noted in patient without trisomy 11. The frequent elevation of p21 protein in aneuploid plasma cells suggests the involvement of the H-ras oncogene in the pathophysiology of MM, which is further supported by a shorter survival among patients with high p21 levels.
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PMID:Correlated flow cytometric analysis of H-ras p21 and nuclear DNA in multiple myeloma. 304 48

Plasma cell malignancy, multiple myeloma, is the prototype of monoclonal terminal-differentiated B cell proliferation that reveals a monoclonal Ig in the serum and/or urine of the majority of patients. New insights into the biology and pathogenesis of this entity are based on careful research to a complex cytokine network including TNF beta, IL-1 beta, and IL-6, many oncogene products such as bc1-2 protein, H-ras p-21 protein, and RB-1 product, and cell surface antigens associated with myeloma cells. The recent understanding on the mechanism for acquisition of IgV region diversity during B cell development has clarified the origin of the clonogenic cell in multiple myeloma. Further identification of new prognostic parameters as well as new therapeutic agents is necessary for the rational therapy of this refractory malignancy.
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PMID:[Advances in biology and pathogenesis of multiple myeloma]. 769 96


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