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

Methylenetetrahydrofolate reductase (MTHFR) plays an important role in carcinogenesis. A decreased incidence of cancer has been reported in the presence of MTHFR 677TT, 1298AC and 1298CC polymorphic variants. We have analysed the MTHFR genotype in 107 multiple myeloma (MM) patients and 86 controls. The MM and control polymorphisms frequencies were: 34% and 48% for 677CC, 53% and 41% for 677CT, 12% and 11% for 677TT; 36% and 43% for 1298AA, 51% and 44% for 1298AC; and 12% and 13% for 1298CC respectively. No statistically significant differences were observed. In addition, no differences were seen according to MM stage, presence of p16 gene hypermethylation or response to treatment.
 ...
PMID:Methylenetetrahydrofolate reductase genotype does not play a role in multiple myeloma pathogenesis. 1206 Jan 27

One-third of patients with monoclonal gammopathy of undetermined significance (MGUS) may progress to multiple myeloma (MM) and may develop a long arm deletion of chromosome 13 (13q-). As the incidence of 13q-, time of development and prognostic impact in MGUS patients is still under debate, we decided to perform serial sequential conventional cytogenetics (CC) and metaphase/interphase fluorescence in situ hybridization (FISH) analyses on bone marrow mononuclear cells obtained from 18 asymptomatic, untreated MGUS patients. Median follow up was 30 months (range 6-72). Interphase FISH identified a 13q14 deletion in five out of 18 patients (on clinical diagnosis in one patient and during the follow up in the remaining four patients). Subsequently, metaphase FISH and CC also identified the deletion in four out of five patients. All five of the patients progressed to MM 6-12 months after 13q- identification, without developing any FISH determined JH rearrangements. MM progression also occurred in two other karyotypically normal patients. We conclude that: (i) the extent of the 13q deletion does not vary during the clinical outcome; (ii)13q- plays a crucial role in MGUS/MM pathogenesis and confers a proliferative advantage to clonal plasma cells being initially demonstrated by interphase FISH and only afterwards by metaphase FISH and CC; and (iii) association of 13q- with t(4;14)(p16.3;q32) remains to be demonstrated. However, a transition from MGUS to MM may also occur in patients with normal karyotypes or other abnormalities, suggesting the possibility of distinct pathogenetic pathways.
 ...
PMID:Long-term follow up with conventional cytogenetics and band 13q14 interphase/metaphase in situ hybridization monitoring in monoclonal gammopathies of undetermined significance. 1213 43

Translocations involving immunoglobulin (Ig) loci and chromosome 13 monosomy (Delta 13) are frequent cytogenetic findings in multiple myeloma (MM). Similar chromosomal aberrations have been identified in the monoclonal gammopathy of undetermined significance (MGUS), but their prevalence and significance remain uncertain. Bone marrow from 72 patients with MGUS (n = 62) and smoldering MM (n = 10) was evaluated for translocations between the Ig heavy chain (IgH) and chromosomes 4, 11, and 16, translocations involving Ig light chain-lambda (IgL-lambda, and Delta 13. Fluorescence in situ hybridization (FISH) analysis was done on clonal plasma cells (PCs) detected by immunofluorescence (cIg-FISH) of the cytoplasmic light chain. We also studied cells for cyclin D1 and FGFR3 up-regulation by immunohistochemistry and immunofluorescence, respectively. Twenty-seven (46%) of 59 patients had IgH translocations, and 4 (11%) of 37 had an IgL-lambda translocation. A t(11;14)(q13;q32) was found in 15 (25%) of 59 patients, a t(4;14)(p16.3;q32) in 9% of patients, and a t(14;16)(q32;q23) in 5% of patients. All patients with t(4;14)(p16.3;q32) tested (n = 3) had intense cytoplasmic fluorescence with an anti-FGFR3 antibody. PC nuclear staining of cyclin D1 was only observed in patients with t(11;14)(q13;q32); Delta 13 was detected in the clonal PCs in 50% of patients. The percentage of abnormal PCs varied with any given abnormality. No obvious clinical or biologic correlations were associated with these chromosome abnormalities. Similar translocations are found in both MGUS and MM, including t(4;14)(p16.3;q32) and t(14;16)(q32;q23). Moreover, Delta 13 is common in MGUS and unlikely to play a predominant role in the evolution of MGUS to MM.
 ...
PMID:Genomic abnormalities in monoclonal gammopathy of undetermined significance. 1256 Feb 43

In order to gain further insights into the role of the p16 gene in cell cycle regulation and the prognostic implications of its inactivation, we investigated the methylation status of the p16 gene in 98 untreated patients using a polymerase chain reaction assay based on the inability of some restriction enzymes to digest methylated sequences. Forty-one patients showed a p16 methylated gene (42%). The percentage of S-phase plasma cells (PC) in these patients was almost three times higher than in those with an unmethylated p16 gene (4.16% +/- 3.37%vs 1.5% +/- 1.41%, P < 0.001). The presence of p16 methylation also correlated with both elevated beta2-microglobulin serum levels and high C-reactive protein values. Patients with a p16 methylated gene had shorter overall and progression-free survival than those patients without p16 methylation. However, this feature did not retain independent prognostic influence on multivariate analysis, probably due to its association with the S-phase PC, which had more potent statistical significance in the Cox model. These findings showed methylation of the p16 gene was a frequent event inMM patients at diagnosis, and was associated with an increased proliferative rate of plasma cells and a poor prognosis, indicating an important role for p16 gene in the cell cycle regulation of multiple myeloma tumour cells, and thus in the clinical outcome of the disease.
 ...
PMID:Methylation is an inactivating mechanism of the p16 gene in multiple myeloma associated with high plasma cell proliferation and short survival. 1219 82

The retinoblastoma protein (pRb), p16(INK4A), D-type cyclins, and their partners cyclin-dependent kinase (CDK) 4 and 6 constitute a G(1) regulatory pathway commonly targeted in tumorigenesis. Several malignancies show a reciprocal correlation between genetic alterations of single members of the pRb pathway. Therefore, we determined the frequency of Rb deletions and cyclin D1 alterations by fluorescence in situ hybridization as well as 5' CpG island hypermethylation of the p16(INK4A)gene using methylation-specific polymerase chain reaction in bone marrow mononuclear cells from 82 individuals with plasma cell disorders. Alterations in at least one of the components of the pathway were found in 75%. Cyclin D1 translocations or amplifications were detected in 14/82 (17.1%), Rb deletions at 13q14 in 23/82 (28%) of the cases, including three (3.6%) homozygous deletions. p16(INK4A) was hypermethylated in 33/57 (57.9%) of the samples. Further analysis revealed a highly significant correlation between cyclin D1 alterations and extramedullar or leukemic myeloma manifestations (P = 0.014; Fisher's test). Whereas Rb deletions seemed to occur alternatively to cyclin D1 alterations, no reciprocal correlation was found between p16(INK4A) hypermethylations and cyclin D1 or Rb locus aberrations. Cyclin D1 locus alterations and Rb deletions were associated with a significantly worse prognosis whereas p16(INK4A) hypermethylation had no impact on survival. We conclude that cyclin D1 and Rb aberrations seem to occur as alternative events in plasma cell malignancies and contribute to clinical course and prognosis. In contrast, although p16(INK4A) hypermethylation is frequent, inactivation of p16(INK4A) seems not to be involved in the pathogenesis of plasma cell disorders.
 ...
PMID:Alterations of the cyclin D1/pRb/p16(INK4A) pathway in multiple myeloma. 1220 Jul 2

This study analyzed the frequency and clinical significance of t(4;14)(p16;q32) in multiple myeloma (MM) among 208 patients with MM and 52 patients with monoclonal gammopathy of undetermined significance (MGUS); diagnosed between 1994 and 2001. Patients with the translocation were identified using reverse transcription-polymerase chain reaction (RT-PCR) to detect hybrid immunoglobulin heavy chain (IgH)-MMSET transcripts from the der(4) chromosome. We found 31 (14.9%) t(4;14)(+) MM patients and 1 (1.9%) t(4;14)(+) MGUS patient. IgH-MMSET hybrid transcripts were detected in bone marrow (BM) and blood. Breakpoint analysis revealed that 67.7% of t(4;14)(+) patients expressed hybrid transcripts potentially encoding full-length MMSET, whereas the remainder lacked one or more amino terminal exons. Expression of fibroblast growth factor receptor 3 (FGFR3), presumptively dysregulated on der(14), was detected by RT-PCR in only 23 of 31 (74%) patients with t(4;14)(+) MM. Patients lacking FGFR3 expression also lacked detectable der(14) products. Longitudinal analysis of 53 MM patients with multiple BM and blood samples showed that, over time, BM from t(4;14)(+) patients remained positive and that t(4;14)(-) patients did not acquire the translocation. IgH-MMSET hybrid transcripts and FGFR3 transcripts disappeared from blood during response to therapy. No correlation was observed between the occurrence of t(4;14) and known prognostic indicators. However, we find the t(4;14) translocation predicts for poor survival (P =.006; median, 644 days vs 1288 days; hazard ratio [HR], 2.0), even in FGFR3 nonexpressors (P =.003). The presence of t(4;14) is also predictive of poor response to first-line chemotherapy (P =.05). These results indicate a significant clinical impact of the t(4;14) translocation in MM that is independent of FGFR3 expression.
 ...
PMID:In multiple myeloma, t(4;14)(p16;q32) is an adverse prognostic factor irrespective of FGFR3 expression. 1239 35

Nonrandom recurrent chromosomal abnormalities are ubiquitous in multiple myeloma (MM) and include, among others, translocations of the immunoglobulin heavy chain locus (IgH). IgH translocations in MM result in the up-regulation of oncogenes, and include more commonly t(11;14)(q13;q32), t(4;14)(p16;q32), and t(14;16)(q32;q23). Based on the recurrent nature of these translocations and their finding since the early stages of the plasma cell (PC) disorders, we hypothesized that they would confer biologic and clinical variability. In addition, deletions of 13q14 and 17p13 have also been associated with a shortened survival. We used cytoplasmic Ig-enhanced interphase fluorescent in situ hybridization to detect deletions (13q14 and 17p13.1), and translocations involving IgH in 351 patients treated with conventional chemotherapy entered into the Eastern Cooperative Oncology Group clinical trial E9486/9487. Translocations were frequently unbalanced with loss of one of the derivative chromosomes. The presence of t(4; 14)(p16;q32) (n = 42; 26 vs 45 months, P <.001), t(14;16)(q32;q23) (n = 15; 16 vs 41 months, P =.003), - 17p13 (n = 37; 23 vs 44 months, P =.005), and - 13q14 (n = 176; 35 vs 51 months, P =.028) were associated with shorter survival. A stratification of patients into 3 distinct categories allowed for prognostication: poor prognosis group (t(4;14)(p16;q32), t(14; 16)(q32;q23), and - 17p13), intermediate prognosis (- 13q14), and good prognosis group (all others), with median survivals of 24.7, 42.3, and 50.5 months, respectively (P <.001). This molecular cytogenetic classification identifies patients into poor, intermediate, and good risk categories. More importantly it provides further compelling evidence that MM is composed of subgroups of patients categorized according to their underlying genomic aberrations.
 ...
PMID:Clinical and biologic implications of recurrent genomic aberrations in myeloma. 1257 22

To study the action, characteristics and expression of high methylation of p15(INK4B) and p16(INK4A) genes in multiple myeloma (MM), the sensitive methylation specific PCR method was employed to detect the hypermethylation of p15(INK4B) and p16(INK4A) in 24 patients with MM. Results showed that the methylation incidence of p15(INK4B) and p16(INK4A) genes were 70.8% (17/24) and 58.3% (14/24) in the MM patients, with the products of 148 bp and 150 bp fragments, respectively. The methylation of p15(INK4B) and p16(INK4A) genes were simultaneously happened in MM patients of plasmocytoma type with two cases at II phase and two cases at III phase. The simultaneous non-methylation of p15(INK4B) and p16(INK4A) genes were founded in five cases of MM patients, all of the tumor cells were of small plasmocyte type with mature differention. Conclusion suggested that there were high incidence of methylation of p15(INK4B) and p16(INK4A) genes in patients with MM. Hypermethylation can be detected in the early stage of disease, which was associated with its progress. It indicated a bad prognosis when methylation happended simultaneously in the two genes. Methylation of p15(INK4B) and p16(INK4A) genes may be related to the pathogeny of MM.
 ...
PMID:[Detection of High Methylation of p15(INK4B) and p16(INK4A) Genes in Multiple Myeloma] 1257 64

Multiple myeloma (MM) is an incurable malignant neoplasm affecting terminally differentiated B-cells. It derives from post-germinal center B-cells and develops as a result of multistep tumorigenic events, because approximately one third of all MM cases have a history of preceding monoclonal gammopathy of undetermined significance (MGUS) or smoldering myeloma. MM terminates in the formation of extramedullary invasion or in secondary plasma cell leukemia. To account for this clinical experience, investigators have found that intrinsic chromosomal instability followed by complex chromosomal translocations/deletions plays a crucial role in the development from MGUS to MM. Representative aberrations include chromosomal rearrangements involving 14q32 loci and deletion at the long arm of chromosome 13. Contributing to the progression of MM itself are genomic instability and altered methylation of the specific gene promoters. The former results in activation of specific oncogenes such as RAS and FGFR3 or in inactivation of p53, and the latter results in inactivation of tumor suppressor genes, including p16. An accurate understanding of each of these molecular events should help clarify the development of specific molecular targeting therapies based on the differences in dysfunctional signaling pathways found in the cells of all MM patients.
 ...
PMID:Multistep tumorigenesis of multiple myeloma: its molecular delineation. 1273 62

Methylation of the p16 (INK4a) tumor suppressor gene is observed frequently in multiple myeloma and various forms of lymphoma and mediates silencing of p16 gene expression. In this investigation, we have determined the effect of the DNA demethylating drug decitabine (DAC; 5-aza-2'-deoxycytidine) on the growth, cell cycle kinetics, RB phosphorylation, and expression of p16 (INK4a) and p21(WAF1) in EBV- human myeloma and EBV+ lymphoblastic cell lines possessing silenced, methylated p16 (INK4a) genes to: (1). evaluate its potential as a therapeutic agent and (2). investigate its mechanism of action. Demethylation of the p16 (INK4a) gene and expression of the p16 (INK4a) protein were observed using higher doses (10(-6)-10(-7)M) of drug while growth inhibition at lower doses (IC(50)=2 x 10(-8)-4 x 10(-8)M) was associated with RB dephosphorylation and increased expression of p21 (WAF1), but not with induction of p16 (INK4a), or apoptosis. Kinetic experiments demonstrated that RB dephosphorylation and the increase of p21 (WAF1) preceded the induction of p16 (INK4a). The drug induced cell cycle arrest at the G1 and G2/M phases. Antisense experiments demonstrated that the G1 arrest was mediated by transcriptional induction of p21(WAF1). In addition to these observed effects on cell cycle regulatory proteins, decitabine also increased phosphorylation of p38 MAP kinase. The G2/M arrest was inhibited by the p38 MAP kinase inhibitor SB203580, indicating that activation of p38 MAP kinase pathway was required for G2/M arrest. Thus, decitabine inhibited growth by inducing cell cycle arrest at the G1 phase mediated by p21(WAF1) and the G2/M phase through activation of the p38 MAP kinase pathway.
 ...
PMID:Decitabine induces cell cycle arrest at the G1 phase via p21(WAF1) and the G2/M phase via the p38 MAP kinase pathway. 1285 93


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>