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)

Mutations affecting the p53 gene have been found associated with many human malignancies, but little is as yet known about multiple myeloma. We investigated p53 gene alterations in 10 human myeloma cell lines (HMCL), half of these being dependent upon exogenous interleukin 6 (IL-6) for in vitro growth, similar to freshly explanted myeloma cells. Using a polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) approach, eight of the 10 HMCL were found to bear a mutated p53 gene. All the mutations were single base substitutions with a predominance of G:C to A:T transitions. There was no apparent relation between the presence of a mutation and IL-6 requirement of the cell line. Interestingly, in two cell lines (XG-2 and XG-4) the SSCP pattern showed the presence of both the wild-type and the mutated allele and, upon reverse PCR on RNA, both alleles were found to be concomitantly expressed at the RNA level. Moreover, three freshly explanted tumor samples had the same p53 gene status (mutated versus wild type) as the HMCL that were derived from them. These results show that p53 mutations are frequent in HMCL. Although no apparent relation could be evidenced with the loss of exogenous IL-6 requirement, it may prove interesting to investigate further potential relations between the presence of a mutated p53 allele and gradual autonomy for cell growth.
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PMID:Mutations of the p53 gene in human myeloma cell lines. 137 72

Four patients with plasma cell leukemia (PCL) and two with multiple myeloma (MM) in transformation had complex numerical and structural chromosome abnormalities. From data published in the literature, the cytogenetic patterns of 46 cases of PCL or MM in the leukemic phase are compared with chromosomal abnormalities found in MM. Although the spectrum of chromosomal abnormalities is comparable in both diseases, the incidence of chromosome abnormalities is higher in PCL than in MM. Hypodiploidy with monosomies for chromosomes 13, 16, 17, and 18 is also more frequent in PCL than in MM. A mutation within the TP53 gene was detected in one of the three patients studied molecularly.
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PMID:Chromosome studies in plasma cell leukemia and multiple myeloma in transformation. 137 39

We looked for mutations of exons 5-8 of the P53 gene in bone marrow cell from 37 cases of multiple myeloma, using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis and DNA sequencing. 25 patients also had cytogenetic analysis. A point mutation, leading to an amino acid change in the P53 protein was found in only one case, involving exon 5. These findings suggest that P53 mutations are very rare in multiple myeloma, and that this disease may be categorized among the few neoplasms where P53 abnormalities have very limited role, if any.
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PMID:Rare occurrence of P53 gene mutations in multiple myeloma. 139 Feb 18

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 last decade has seen major advances in the acquisition of knowledge concerning both the cellular and molecular genetics of multiple myeloma. Although discrete and specific changes associated with the plasma cell disorders have yet to be identified, a pattern is emerging that one can associate with the plasma cell disorders. This pattern includes the frequent involvement of chromosomes 1 and 14, and in particular presence of the 14q+ abnormality. But in addition there are typically many other numeric and/or structural changes that can, in fact, involve almost any chromosome, but particularly chromosomes 3, 5, 6, and 7, as well as 11, 14, 17, and 18. The presence of one or more unidentified marker chromosomes is also a typical feature. The ongoing challenges include identification of a crucial initial genetic change (if such exists) as well as the factors contributing to the ongoing karyotypic evaluation that results in complex karyotypes in patients with advanced disease. There is no doubt that the complex karyotypic picture contributes to the major heterogeneity of plasma cells that occurs in malignant plasma cell disorders. Karyotypic complexity underlies heterogeneity in cell morphology, surface antigen expression, response to cytokines, and a variety of other functional characteristics. The aberrant expression of antigens normally found on other hematopoietic progenitors has led to speculation about the true nature of the stem cell in myeloma. The overriding challenge, however, is to fully understand the plasma cell disorders at the molecular level. Although changes have already been noted in the functions of C-myc, the ras family of oncogenes, Bcl-2 expression, and several so called anti-oncogenes such as p53, it is likely that we have only begun to scratch the surface in the area of molecular changes. The potential for involvement at multiple molecular sites and the possibility of complex interactions between gene segments is truly overwhelming. However, it is hoped that at the molecular level a pattern will ultimately emerge. It is most interesting, as previously discussed, that there is an interplay among C-myc, N-ras, Bcl-2, and the Epstein-Barr virus in the predilection for a plasma cell phenotype. Undoubtedly there is much more to learn, and it is truly exciting to finally have some tools and probes at hand to more effectively study the genome in multiple myeloma and related disorders.
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PMID:Cellular and molecular genetic features of myeloma and related disorders. 158 85

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

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

The expression of three growth-regulated protooncogenes, c-myc, c-myb, and p53, and the S-phase-specific histone H3 gene, was compared in bone marrow cells from multiple myeloma patients and normal controls by measuring the amount of specific RNA by Northern blot analysis. Four samples contained at least 72% of myeloma cells, one sample 43%, and one 11%. Expression of the protooncogenes was similar in normal and myeloma bone marrow cells, whereas that of histone H3 gene was significantly reduced (between 10 and 15 times) in samples containing at least 43% of malignant plasma cells and not detectable in those containing more than 72% of neoplastic cells. Protooncogene levels of expression were compared to those of the H3 gene to distinguish the increased expression of a growth-regulated gene due to a true deregulation from overexpression reflecting solely an increase in the fraction of cycling cells. The ratios of expression of protooncogenes to histone H3 were markedly increased in multiple myeloma cells; the highest ratios were found in the patients with the highest number of malignant plasma cells. These results suggest that the expression of three growth-regulated oncogenes (c-myc, c-myb, p53) is altered in myelomatous plasma cells.
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PMID:Altered expression of growth-regulated protooncogenes in human malignant plasma cells. 266 53

It has been shown recently that the c-mos oncogene becomes activated in myeloma XRPC-24 via insertion of an intracisternal A particle (IAP) long terminal repeat (LTR). The inserted LTR serves as a promoter from which transcription of the 3' rearranged c-mos initiates. The insertion is in a head-to-head orientation such that the transcriptional orientations of the IAP and the 3' rearranged c-mos are opposite. It has already been shown that this IAP LTR has two promoters, one transcribing the IAP genome and the other transcribing the rearranged c-mos. Since the IAP genomes are actively transcribed in mouse myelomas but not in normal cells, it was interesting to test whether transcriptional activation of the IAP occurs in the presence of active oncogene products, especially nuclear ones. The 5' LTR of the IAP inserted in myeloma XRPC-24 was chosen as a convenient model to test the effect of viral and cellular oncogene products. These included simian virus 40 (SV40) large-T antigen, the adenovirus early 1A (E1A) gene product, the myc gene product, and p53. The LTR was coupled to the bacterial gene coding for chloramphenicol acetyltransferase (CAT) in two orientations, and the levels of CAT directed by the LTR promoters were assayed in either the presence or the absence of the oncogene products. The levels of CAT directed by the 5' LTR promoter transcribing the IAP were significantly elevated in the presence of SV40 large-T antigen, the adenovirus E1A and myc gene products, and p53. The promoter transcribing the rearranged c-mos was transactivated by SV40 large-T antigen and the adenovirus E1A gene product. The results indicate that oncogene products may have an important role in turning on promoters of other genes. The IAP LTR may serve as a useful model for studying the effect of various gene products on promoters which are known to be activated in the malignant state.
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PMID:The long terminal repeat of the intracisternal A particle as a target for transactivation by oncogene products. 293 1

Hormonal treatment of advanced prostatic cancer patients generally results in an initially beneficial response, but the treated patients develop hormonally resistant disease in which no curative therapy is currently available. Recent studies have revealed that interleukin 6 (IL-6) is a growth factor for myeloma, renal cell carcinoma, and certain T-cell lymphomas. Further, IL-6 has been shown to block apoptosis induced by p53, transforming growth factor beta, and certain cancer chemotherapeutic compounds. The objective of the present study was to determine whether IL-6 is a growth factor for two human prostate cancer lines and whether it protects the tumor cells from drug-induced cell death. Two hormone-independent prostate cell lines were used in this study, namely PC-3 and DU145, and these have been shown to be relatively resistant to cis-diamminedichloroplatinum (CDDP), etoposide (VP-16), and adriamycin (ADR). Both cell lines express IL-6 mRNA and secrete IL-6 constitutively. The addition of anti-IL-6 antiserum to the cell lines resulted in a significant inhibition of cell growth up to day 2, and when additional antibody was added at day 2 the inhibition persisted for 4 days. The coaddition of anti-IL-6 antiserum and CDDP or VP-16 resulted in synergy in cytotoxicity in both cell lines, whereas the combination of antibody and ADR or suramin resulted only in additive effects. Sequential treatment revealed that anti-IL-6 antibody was required to achieve synergy, whereas either sequence of pretreatment resulted in synergy with anti-IL-6 and CDDP but not with VP-16. CDDP treatment of tumor cells down-regulated IL-6 mRNA expression and IL-6 secretion. The present findings demonstrate that IL-6 is an autocrine/paracrine growth factor for DU145 and PC-3 prostate lines. Additionally, the secretion of this cytokine protects the tumor cells against the cytotoxic effect of CDDP and VP-16 and its neutralization sensitizes the cells to cytotoxicity. Overall, the studies suggest that agents that can down-regulate or inhibit protective factors in tumors may overcome drug resistance.
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PMID:Endogenous interleukin 6 is a resistance factor for cis-diamminedichloroplatinum and etoposide-mediated cytotoxicity of human prostate carcinoma cell lines. 755 41


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