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)

Cyclin D1 (CyD1)/BCL1 (PRAD1) is expressed at high levels in almost all cases of mantle cell leukemia/lymphoma (MCL) and in rare cases of chronic lymphocytic leukemia (CLL). The CyD1/BCL1 protein plays an important role in the progression of cells through the G1 phase of cell cycle. Most of the CyD1/BCL1 protein expression studies are performed using immunohistochemistry. We used a sensitive solid-phase radioimmunoassay (RIA) to quantify CyD1 protein expression in 199 patients with CLL. Of these 137 patients were previously untreated with the rest having had standard chemotherapeutic regimens including alkylating agents and fludarabine before being referred to our center. Median white cell count in these patients was 49x10(3) /microl (range 3.0-438.5x10(3)/microl), hemoglobin level 13.1 g/dl (range 5.2-17.3 g/dl), platelet count 157x10(3) /microl (range 10-377x10(3) /microl), age 58 (range 26-89), and beta2-microglobulin 2.75 mg/dl (range 1.1-14.3). The median radioactivity (CPM) of mononuclear cells obtained from 56 normal individuals was assigned a value of 1. There was no significant variation in CyD1 levels among normal individuals (SD=0. 12). While most CyD1 levels in MCL varied from 6.5 to 15.6, the median CyD1/BCL1 in CLL was 1.4 with 75th percentile under 2.12. Rare CLL cases (3.5%) showed levels between 4 and 8.83. When divided into two groups at the median level, patients with higher CyD1/BCL1 expression had shorter survival (P = 0.03). This remained true when applied only to the previously untreated patients (P=0.05). Despite the relatively low expression, the CyD1/BCL1 levels in univariate analysis were as good or better predictors of survival than Binet (P = 0.03) or Rai (P = 0.05) staging. Furthermore, CyD1/BCL1 levels correlated with serum beta2-microglobulin (P = 0.001), white blood cell count (P = 0.004) and hemoglobin levels at the time of collection (P = 0.0003) but not with lymphocyte count, platelet count or age. The data demonstrate that CyD1/BCL1 is likely to play a significant role in the biology of CLL and can be used as a prognostic indicator. Further studies to clarify the role of CyD1 in the biology of CLL and its value as a prognostic indicator at the time of diagnosis are encouraged.
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PMID:Variations in the low levels of cyclin D1/BCL1 have prognostic value in chronic lymphocytic leukemia. 1078 79

Similar to the R.E.A.L-System, the small cell B-cell lymphomas of the new WHO classification consist of chronic lymphocytic leukaemia of B cell type, mantle cell lymphoma, follicular lymphoma, lymphoplasmocytic lymphoma/immunocytoma, hairy cell leukaemia, as well as plasmacytoma. The only major difference between the WHO- and the REAL-classification is the consideration of prolymphocytic leukaemia as a single disease entity in the former system. All the above-mentioned lymphomas arise from B cells of varying stages of differentiation and, therefore, often demonstrate architectural, cytological and immunophenotypic characteristics of their normal physiological counterparts. Consideration of tumour cell growth pattern, -cytology, -immunophenotype and -growth fraction, together with the presence and consistency of the reactive cell infiltrate, usually leads to categorisation of a lymphoma in the majority of cases. The molecular biological characteristics of follicular lymphoma and mantle cell lymphoma are the best defined of the small cell B-cell lymphomas. Chromosomal translocations involving the immunoglobulin heavy chain genes and the bcl-2 gene or Cyclin D1 gene, respectively, probably belong to the initial changes in a cell, which, together with several subsequent unidentified genetic alterations, lead to the development of these tumours. Although nodal small cell B-cell lymphomas are usually diagnosed at an advanced stage of the disease, the progression of the disease--with the exception of mantle cell lymphomas--is often indolent. As a result, the small cell B-cell lymphomas were previously considered as "low-grade" Non-Hodgkin lymphomas in the Kiel classification. However, since the progress of a lymphoma subtype can be heterogeneous and since mantle cell lymphomas cannot really be considered as "low-grade" tumours, "umbrella grading" of lymphomas has been discarded in the WHO classification, with emphasis being placed on grading within a lymphoma disease entity. In the following pages, the characteristics important for the diagnosis and categorisation of the small cell B-cell lymphomas will be summarised. Further, we present information regarding the molecular biological and clinical characteristics of these lymphomas.
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PMID:[Small cell B-cell lymphomas: guidelines for differential diagnosis]. 1084 Aug 20

To investigate the role of the cell cycle regulators p21(Waf1), p27(Kip1), retinoblastoma (Rb), and cyclin D1 in Richter's transformation of chronic lymphocytic leukemia (CLL), we analyzed 19 CLL and eight Richter's syndrome (RS) tumors, previously characterized for p53 and ARF/INK4a abnormalities. p21(Waf1)immunohistochemical expression was negative in 12 of 15 CLL (80%), whereas it was moderate or strong in three of seven RS (43%). p21(Waf1) gene was in germline configuration in all the tumors analyzed. Four immunohistochemical patterns of p53 and p21(Waf1) expression were observed: (1) p53-/p21- in 10 of 15 CLL (67%), but only in two of six RS (33%); (2) p53+/p21+ in three CLL (20%) and two RS (33%); (3) p53-/p21+ in one RS; and (4) p53++/p21- in two CLL and one RS. Two p53+/p21+ CLL evolved into RS. p53 mutations clustered around the p53++/p21- (two CLL and one RS) and p53-/p21- (one CLL and one RS) tumors. While the majority of CLL displayed strong p27 immunoreactivity, RS tumors were constantly p27-negative. p27(Kip1) gene was in germline configuration in all the tumors analyzed. Most CLL cases were negative for Rb expression. In contrast, all RS exhibited strong Rb expression. Cyclin D1 overexpression was only detected in one CLL evolving into RS and one RS. In conclusion, a p53+/p21- immunohistochemical pattern is shown exclusively by p53-mutated CLL/RS. Additionally, our results suggest a possible implication of moderate/strong p21(Waf1) expression, loss of p27 expression, and cyclin D1 overexpression in the Richter's transformation of CLL.
Leukemia 2002 Jun
PMID:Multiple cell cycle regulator alterations in Richter's transformation of chronic lymphocytic leukemia. 1204 Apr 34

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.
Leukemia 2002 Sep
PMID:Alterations of the cyclin D1/pRb/p16(INK4A) pathway in multiple myeloma. 1220 Jul 2

Cyclin D1 is a positive-regulator of the cell cycle and is overexpressed in myeloma cells with t(11;14)(q13;q32). First, we analyzed whether there was a correlation between cyclin D1 overexpression and the presence of Ki67-positive myeloma cells in multiple myeloma (MM). Cyclin D1 overexpression was examined by competitive RT-PCR. Then we found these two markers were present independently in a given case. FISH analysis revealed that cyclin D1 over-expression was caused by t(11;14)(q13;q32) or extra copies of B-cell leukemia/lymphoma-1 (BCL-1/CCND1), and unknown mechanism without them. We compared the gene expression between myeloma cells with cyclin D1 overexpression and those without it using cDNA microarray analysis. Analysis of the expression profiles showed that the significantly up-regulated genes included cyclin D1, cell division cycle 37 (CDC37) and B-cell leukemia/lymphoma-2 (BCL-2), while the down-regulated genes included cyclin D2 and CD9 antigen (p24) in MM cases with cyclin D1 overexpression. However, hierarchical clustering analysis of the data showed that myeloma cells of MM cases with cyclin D1 overexpression could not be distinguished clearly from those without it. Real-time RT-PCR showed that the expression of CDC37 gene was significantly up-regulated in MM patients with cyclin D1 overexpression compared with those without it (p=0.0418). However, there was no significant difference in BCL-2 gene (p=0.5748). These results suggested that MM cases with cyclin D1 overexpression do not constitute a specific group, and cyclin D1 overexpression may not be caused only by abnormality of the BCL-1/CCND1 gene. The CDC37 may collaborate with cyclin D1 in progression of MM.
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PMID:Cyclin D1 overexpression is not a specific grouping marker, but may collaborate with CDC37 in myeloma cells. 1528 59

The Benzopyrones are a group of compounds whose members include coumarins and flavonoids. Dietary exposure to benzopyrones is quite significant, as these compounds are found in vegetables, fruit, seeds, nuts, coffee, tea and wine. It is estimated that the average western diet contains approximately 1 g/day of mixed benzopyrones. It is, therefore, not difficult to see why extensive research into their pharmacological and therapeutic properties is underway over many years. Coumarin is a natural substance that has shown anti-tumour activity in vivo, with the effect believed to be due to its metabolites (e.g. 7-hydroxycoumarin). This review is based on recent studies of coumarins and coumarin related compounds. Therefore, the focus will be on these relevant compounds and their therapeutic importance. A recent study has shown that 7-hydroxycoumarin inhibits the release of Cyclin D1, which is overexpressed in many types of cancer. This knowledge may lead to its use in cancer therapy. Esculetin inhibits growth and cell cycle progression by inducing arrest of the G(1) phase in HL-60 leukaemia cells, resulting from the inhibition of retinoblastoma protein phosphorylation. Recent studies investigating the potential of flavonoids as therapeutic agents have suggested they may have use in various therapeutic settings ranging from leukaemia treatment to the treatment of patients with HIV. Genistein is a well-known isoflavone and is a tyrosine kinase inhibitor. Studies have indicated that genistein elicits inhibitory effects on cell growth of various carcinoma cell-lines and may be a potential candidate for cancer therapy. In our research, we have investigated the effects of coumarins and coumarin-related compounds on a panel of cell-lines. The most recent work involves two cell-lines, MCF-7 a breast carcinoma and A549 a lung carcinoma. Microtitre assays were performed along with real-time analysis of cell viability using a biosensor called the Cytosensor microphysiometer. These studies suggest that both genistein and esculetin exerted the most potent inhibitory effect on cell growth in comparison to the other two compounds.
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PMID:Studies on coumarins and coumarin-related compounds to determine their therapeutic role in the treatment of cancer. 1557 72

An undifferentiated status and the epigenetic inactivation of tumor-suppressor genes are hallmarks of transformed cells. Promoter CpG island hypermethylation of differentiating genes, however, has rarely been reported. The Groucho homologue Transducin-like Enhancer of Split 1 (TLE1) is a multitasked transcriptional corepressor that acts through the acute myelogenous leukemia 1, Wnt, and Notch signaling pathways. We have found that TLE1 undergoes promoter CpG island hypermethylation-associated inactivation in hematologic malignancies, such as diffuse large B-cell lymphoma and AML. We also observed a mutual exclusivity of the epigenetic alteration of TLE1 and the cytogenetic alteration of AML1. TLE1 reintroduction in hypermethylated leukemia/lymphoma cells causes growth inhibition in colony assays and nude mice, whereas TLE1-short hairpin RNA depletion in unmethylated cells enhances tumor growth. We also show that these effects are mediated by TLE1 transcriptional repressor activity on its target genes, such as Cyclin D1, Colony-Stimulating Factor 1 receptor, and Hairy/Enhancer of Split 1. These data suggest that TLE1 epigenetic inactivation contributes to the development of hematologic malignancies by disrupting critical differentiation and growth-suppressing pathways.
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PMID:Epigenetic inactivation of the Groucho homologue gene TLE1 in hematologic malignancies. 1851 70

Cyclin D1 overexpression is the hallmark of mantle cell lymphoma (MCL). However, the importance of cyclin D1 in the maintenance and progression of the disease remains to be defined. The aim of this study was to elucidate the role of cyclin D1 overexpression using an efficient cyclin D1-shRNA and a lentiviral system in well-characterized MCL cell lines. Surprisingly, the knockdown of cyclin D1 led to a moderate retardation in growth, without induction of apoptosis. The cyclin D1-shRNA-transduced MCL cells showed a 15% shift from S phase to G(1) phase of the cell cycle, a weak induction of p27(Kip1), decreased Rb (Ser807/811) phosphorylation, and a consistent upregulation of cyclin D2 mRNA and protein expression. However, double knockdown of cyclins D1 and D2 did not intensify the effects observed with cyclin D1 knockdown alone. These data suggest that the moderate effects of cyclin D1 downregulation on survival and proliferation are likely the result of compensatory cyclin-independent mechanisms governing proliferation or alternatively, secondary genetic events that make cyclin D1 dispensable. These findings have important implications for MCL therapy, as strategies targeting only cyclin D1 function might be hampered by compensatory regulatory mechanisms, resulting in a low probability of treatment response.
Leukemia 2008 Nov
PMID:Specific lentiviral shRNA-mediated knockdown of cyclin D1 in mantle cell lymphoma has minimal effects on cell survival and reveals a regulatory circuit with cyclin D2. 1868 13

The role of the Notch1 pathway has been well assessed in leukemia. Notch1 mutations are the most common ones in T acute lymphoblastic leukaemia patients which carry either oncogenic Notch1 forms or ineffective ubiquitin ligase implicated in Notch1 turnover. Abnormalities in the Notch1-Jagged1 system have been reported also in acute myelogenous leukaemia (AML) patients where Jagged1 is frequently over-expressed. Moreover, activating Notch1 mutations, as well, can occur in human AML and in leukemia cases with lineage infidelity. As a result, Notch1 signalling inhibition is an attractive goal in leukaemia therapy. Blockage/delay in cell differentiation and/or increase of proliferation are the main results of Notch1 signalling activation in several leukemic cell lines. Moreover, specific genes involved in cell growth control have been identified as Notch1 transcriptional targets, i.e. Cyclin D1 and c-Myc. 4-Hydroxynonenal (HNE), an aldehyde produced during lipid peroxidation, is involved in several pathological and physiological conditions, including inflammation; atherosclerosis; and neurodegenerative and chronic liver diseases. Moreover HNE has an antiproliferative/ differentiative effect in several cell lines, by affecting the expression of key genes, such as oncogenes (e.g. c-Myc, c-Myb), cyclins and telomerase. This prompted us to study the effect of HNE on Notch1 expression and its related signalling in HL-60 cells, a leukemic cell line widely used for differentiation studies. RT-PCR as well as Western blot assay showed Notch1down-regulation in HNE-treated HL-60 cells. The expression of Hes1, a Notch1 target gene, was concomitantly down-regulated by HNE treatment, reflecting Notch1 signalling inhibition. DAPT, an inhibitor of Notch activity, when added contemporary to HNE, further increased cell growth inhibition, without affecting apoptosis. Moreover, DAPT treatment reversed the HNE-induced differentiation. Overall these results suggest that Notch1 is a target for HNE and its down regulation is a key event in HNE-mediated inhibition of cell proliferation in the HL-60 cell line. By contrast our data do not support a role for Notch1 in HNE- induced differentiation or apoptosis.
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PMID:Down-regulation of Notch1 expression is involved in HL-60 cell growth inhibition induced by 4-hydroxynonenal, a product of lipid peroxidation. 1899 39

Here, we synthesized two phospha sugar derivatives, 2,3,4-tribromo-3-methyl-1-phenylphospholane 1-oxide (TMPP) and 2,3-dibromo-3-methyl-1-phenylphospholane 1-oxide (DMPP) by reacting 3-methyl-1-phenyl-2-phospholene 1-oxide with bromine, and investigated their potential as antileukemic agents in cell lines. Both agents showed inhibitory effects on leukemia cell proliferation, with mean IC(50) values of 6.25 micromol/L for TMPP and 23.7 micromol/L for DMPP, indicating that inhibition appeared to be dependent on the number of bromine atoms in the structure. Further, TMPP at 10 micromol/L and DMPP at 20 micromol/L induced G2/M cell cycle block in leukemia cells, and TMPP at 20 micromol/L induced apoptosis in these cells. TMPP treatment effected a reduction in both cell cycle progression signals (FoxM1, KIS, Cdc25B, Cyclin D1, Cyclin A, and Aurora-B) and tumor cell survival (p27(Kip1) and p21(Cip1)), as well as induced the activation of caspase-3 and -9. Further, treatment with TMPP significantly reduced the viability of AML specimens derived from AML patients, but only slightly reduced the viability of normal ALDH(hi) progenitor cells. We also observed that FoxM1 mRNA was overexpressed in AML cells, and treatment with TMPP reduced FoxM1 mRNA expression in AML cells. Here, we report on the synthesis of TMPP and DMPP and demonstrate that these agents hinder proliferation of leukemia cells by FoxM1 suppression, which leads to G2/M cell cycle block and subsequent caspase-3-dependent apoptosis in acute leukemia cells. These agents may facilitate the development of new strategies in targeted antileukemic therapy.
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PMID:Development and pharmacologic characterization of deoxybromophospha sugar derivatives with antileukemic activity. 1943 53


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