cyclin-d1 and Leukemia

Cyclin D1 (CCND1) is a key protein involved in cell-cycle regulation, and the CCND1 G870A polymorphism is associated with many types of malignancy. Studies examining the associations between this G870A polymorphism and susceptibility to leukemia and hepatocellular carcinoma (HCC) have shown inconsistent results. Therefore, we conducted a meta-analysis to clarify these associations. A search of the PubMed database yielded 7 relevant articles: 3 pertaining to leukemia and 4 to HCC. The odds ratios (ORs) from individual studies were pooled using a fixed or random-effect model. A significant association was observed between the CCND1 G870A variant and leukemia under the allele contrast model [P = 0.003, OR = 1.49, 95% confidence interval (CI) = 1.15-1.95], the homozygote contrast model (P = 0.003, OR = 2.30, 95%CI = 1.34-3.96), and the recessive model (P = 0.002, OR = 2.03, 95%CI = 1.29-3.21). A significant association was observed between this variant and HCC under the recessive model (P = 0.0006, OR = 1.62, 95%CI = 1.23-2.14), the dominant model (P = 0.002, OR = 1.59, 95%CI = 1.19-2.14), the homozygote contrast model (P < 0.0001, OR = 2.06, 95%CI = 1.45-2.94), and the allele contrast model (P < 0.0001, OR = 1.43, 95%CI = 1.20-1.69). Our findings suggest that heritable CCND1 status may influence the risk of developing leukemia and HCC, and that more attention should be given to carriers of these susceptibility genes.

Topics: Alleles; Carcinoma, Hepatocellular; Cyclin D1; Gene Expression; Genetic Predisposition to Disease; Homozygote; Humans; Inheritance Patterns; Leukemia; Liver Neoplasms; Models, Genetic; Odds Ratio; Polymorphism, Single Nucleotide

In recent years, mounting evidence has indicated that the CCND1 G870A gene polymorphism, which impacts the mitotic cell cycle, may influence leukemia or non-Hodgkin lymphoma risk. Unfortunately, the previous results were inconsistent. Therefore, a meta-analysis was performed to obtain a more precise estimation of any association. We conducted a search in PubMed, Embase and CNKI covering all published papers up to March, 2014. A total of 9 publications including 10 case-control studies met the inclusion criteria. Odds ratios (ORs) and their 95% confidence intervals (95%CIs) were applied to assess association. The pooled ORs showed significant association in non-Hodgkin lymphoma (comparison A vs G: OR= 1.114, 95%CI=1.053-1.179, p=0.000; homozygote comparison AA vs GG: OR=1.245, 95%CI=1.110-1.396, p=0.000; heterozygote comparison AG vs GG: OR=1.095, 95%CI=1.000-1.199, p=0.05; dominant model AA/GA vs GG: OR=1.137, 95%CI=1.043-1.239, p=0.003; and recessive model AA vs. OR=1.177, 95%CI=1.066-1.301, p=0.001). However, there was no association between the CCND1 G870A polymorphism and leukemia risk. In conclusion, the CCND1 G870A polymorphism may increase risk of non-Hodgkin lymphoma, but not leukemia. However, more primary large scale and well-designed studies are still required to evaluate the interaction of CCND1 G870A polymorphism with leukemia and non-Hodgkin lymphoma risk.

Topics: Cyclin D1; Gene Frequency; Genetic Association Studies; Genetic Predisposition to Disease; Leukemia; Lymphoma, Non-Hodgkin; Polymorphism, Single Nucleotide; Risk

The t(11;14)(q13;q32) resulting in cyclin D1 overexpression is consistently present in mantle cell lymphoma. However secondary chromosomal aberrations are also extremely common. Of these, 8q24 abnormalities associated with the t(11;14) are rare. Over the course of 10 years at M.D. Anderson Cancer Center, we identified five cases of mantle cell lymphoma in which conventional cytogenetic analysis revealed complex karyotypes, including the t(11;14) and 8q24 abnormalities: one with t(8;14)(q24;q32), one with t(2;8)(q13;q24), and three with add(8)(q24). We performed fluorescence in situ hybridization (FISH) studies on all cases. In the case with the t(8;14), IgH/myc fusion signals were identified, and in the case with the t(2;8), split c-myc signals were detected. In the three cases with add(8)(q24), one case had split c-myc signals and two cases had three copies of c-myc. Thus, the c-myc gene was involved in all cases. All five neoplasms had blastoid morphologic features, and four cases, including the cases with the t(8;14) and t(2;8), had leukemic involvement. We conclude that 8q24 abnormalities involving the c-myc gene are uncommon secondary abnormalities that occur in a subset of mantle cell lymphomas. C-myc gene abnormalities are associated with blastoid cytologic features and also may be associated with leukemic involvement.

Topics: Aged; Antigens, CD; Chromosome Aberrations; Chromosomes, Human, Pair 11; Chromosomes, Human, Pair 14; Chromosomes, Human, Pair 2; Chromosomes, Human, Pair 8; Cyclin D1; Female; Genes, myc; Humans; Immunoglobulin Heavy Chains; Immunohistochemistry; Immunophenotyping; In Situ Hybridization, Fluorescence; Ki-67 Antigen; Leukemia; Leukosialin; Lymphoma, Mantle-Cell; Male; Middle Aged; Sialoglycoproteins; Translocation, Genetic

DNA methylation was considered as prognostic information in some hematological malignancies. Previous studies have reported the in vitro and in vivo biology role of mesenchymal stem cells (MSCs) on leukemic cells. The aim of this study was to investigate the effect of MSCs on the promoter methylation status of hTERT as a catalytic subunit of telomerase enzyme.. In the experimental study, the Molt-4 leukemic cells were co-cultured with MSCs for 7 days. At the end of the co-culture period, the Molt-4 cells were collected, DNA and protein were extracted. Then methylation specific-PCR and western blotting were done for evaluating the hTERT gene promoter methylation status and cyclin D1 and hTERT protein expression, respectively. In the following, the flow cytometry was done for cell cycle distribution assay.. It was found that MSCs resulted in a significant decrease in the cyclin D1 and hTERT protein expression levels. Also, MSCs caused changes in the methylation status of the CpG islands in the hTERT gene promoter region. The following results showed that MSCs caused a significant increase in the number of cells at G0/G1 phase and arrest the G0/G1 phase as well as decrease in the cell proliferation of Molt-4 cells.. It is concluded that co-culture of MSCs with Molt-4 cells could be involved in changing the methylation status of hTERT gene promoter, cell cycle and hTERT protein expression; it could be potentially beneficial for further investigations regarding the cell transplantation and cell-based therapy.

Topics: Adipose Tissue; CpG Islands; Cyclin D1; DNA Methylation; Humans; Leukemia; Mesenchymal Stem Cells; Promoter Regions, Genetic

Endothelial cells (ECs) are a critical component of the hematopoietic niche, and the cross-talk between ECs and leukemia was reported recently. This study aimed to determine the genes involved in the proliferation inhibition of endothelial cells in leukemia.. Human umbilical vein endothelial cells (HUVEC) were cultured alone or co-cultured with K562 cell lines. GeneChip assays were performed to identify the differentially expressed genes. The Celigo, MTT assay, and flow cytometric analysis were used to determine the effect of RNAi DIDO on cell growth and apoptosis. The differently expressed genes were verified by qRT-PCR (quantitative real-time PCR) and western-blot.. In K562-HUVEC co-cultured cell lines, 323 down-regulated probes were identified and the extracellular signal-regulated kinase 5 (ERK5) signaling pathway was significantly inhibited. Among the down-regulated genes, the. The knock-down of

Topics: Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase 6; Human Umbilical Vein Endothelial Cells; Humans; Leukemia

Ring finger proteins contain a characteristic ring finger motif and perform a wide range of biological functions in living organisms. These genes are abnormally expressed in many cancers. We found that the expression level of Ring finger protein 220 (RNF220) was negatively correlated with the disease-free survival (DFS) and overall survival (OS) of acute myeloid leukaemia (AML) patients. Moreover, the mRNA level of this gene is significantly higher in the bone marrow cells of AML patients than in the mobilized peripheral blood haematopoietic stem cells of healthy donors. The overexpression of RNF220 promotes the proliferation of AML cells and accelerates the transition from G1 phase to S phase. Increased protein levels and decreased ubiquitylation levels of Cyclin D1 were observed in the nuclei of cells overexpressing RNF220 compared to those of control cells. The protein level of USP22 was also increased in cells overexpressing RNF220. RNF220 cannot enhance the stability of the Cyclin D1 protein without increased expression of the USP22 protein. Our study provided proof of principle to show that RNF220 promotes stabilization of the Cyclin D1 protein via USP22.

Topics: Cell Line, Tumor; Cell Proliferation; Cyclin D1; G1 Phase; Humans; Leukemia; Proteolysis; S Phase; Ubiquitin Thiolesterase; Ubiquitin-Protein Ligases

Topics: Apoptosis; bcl-2-Associated X Protein; Benzophenones; Cell Cycle Checkpoints; Cell Line, Tumor; Cyclin D1; Cytotoxins; Humans; Leukemia; Magnetic Resonance Spectroscopy; Molecular Structure; Polycyclic Compounds; Proto-Oncogene Proteins c-bcl-2; Resting Phase, Cell Cycle; Spectrometry, Mass, Electrospray Ionization

A BCL1 leukemia-cell-targeted polymer-drug conjugate with a narrow molecular weight distribution consisting of an N-(2-hydroxypropyl)methacrylamide copolymer carrier and the anticancer drug pirarubicin is prepared by controlled radical copolymerization followed by metal-free click chemistry. A targeting recombinant single chain antibody fragment (scFv) derived from a B1 monoclonal antibody is attached noncovalently to the polymer carrier via a coiled coil interaction between two complementary peptides. Two pairs of coiled coil forming peptides (abbreviated KEK/EKE and KSK/ESE) are used as linkers between the polymer-pirarubicin conjugate and the targeting protein. The targeted polymer conjugate with the coiled coil linker KSK/ESE exhibits 4× better cell binding activity and 2× higher cytotoxicity in vitro compared with the other conjugate. Treatment of mice with established BCL1 leukemia using the scFv-targeted polymer conjugate leads to a markedly prolonged survival time of the experimental animals compared with the treatment using the free drug and the nontargeted polymer-pirarubicin conjugate.

Topics: Acrylamides; Animals; Antibodies, Monoclonal; Click Chemistry; Cyclin D1; Disease Models, Animal; Drug Carriers; Drug Delivery Systems; Humans; Immunoconjugates; Immunoglobulin Fragments; Leukemia; Mice; Molecular Targeted Therapy; Peptides; Polymers

Quercetin is one of the most abundant flavonoids, present in fruits and vegetables and has been shown to have multiple properties capable of reducing cell growth in cancer cells. Green tea is a widely consumed beverage, known for a potential source of free radical scavenging and anti-cancer activities. Herein, we investigate the in vivo antitumor efficacy of quercetin and green tea in human leukemia. Human tumors were xenografted into NOD/SCID mice. Quercetin and green tea reduced tumor growth in HL-60 xenografts accompanied by decreased expression of anti-apoptotic proteins, BCL-2, BCL-XL and MCL-1 and increased expression of BAX, a pro-apoptotic protein. Moreover, caspase-3 was activated to a greater extent after quercetin and green tea treatment. Quercetin and green tea also mediated G1 phase cell cycle arrest in HL-60 xenografts. Treatment with quercetin and green tea induced conversion of LC3-I to LC3-II as well as activation of autophagy proteins, suggesting that quercetin and green tea initiate the autophagic progression. We have provided evidence that quercetin and green tea induces signaling at the level of apoptosis, cell cycle and autophagy which converge to antigrowth effects in HL-60 xenograft mice suggesting that these compounds may be a compelling ally in cancer treatment.

Topics: Animals; Apoptosis; Apoptosis Regulatory Proteins; Autophagy; bcl-2-Associated X Protein; bcl-X Protein; Cyclin D1; Female; G1 Phase Cell Cycle Checkpoints; Heterografts; HL-60 Cells; Humans; Leukemia; Mice; Mice, Inbred NOD; Mice, SCID; Microtubule-Associated Proteins; Myeloid Cell Leukemia Sequence 1 Protein; Quercetin; Signal Transduction; Tea; Xenograft Model Antitumor Assays

Evodiamine, a quinolone alkaloid, is one of the major bioactive compounds of Evodia rutaecarpa Bentham (Rutaceae). It exhibits excellent biological activities, especially the anticancer activity. This study aims to investigate the effect of evodiamine on the proliferation of leukemia cell line K562 and to explore the underlying mechanism. The effect of evodiamine on K562 cells proliferation was analyzed by trypan blue dye exclusion assay and MTT assay. The expression levels of peroxisome proliferators-activated receptor gamma (PPARγ), cyclin D1, and p21 were detected by western blot assay. The results demonstrated that evodiamine inhibited the proliferation and decreased the viability of K562 cells in a dose- and time-dependent manner. 2-Chloro-5-nitro-N-phenylbenzamide (GW9662) and/or PPARγ-siRNA pretreatment alleviated the cell growth suppression triggered by evodiamine. Meanwhile, evodiamine intervention elevated the expression of PPARγ in K562 cells, while pretreatment with GW9662 attenuated the enhanced upregulation of PPARγ expression induced by evodiamine. In addition, GW9662 and PPARγ-siRNA pretreatment also significantly attenuated the downregulation of the cell cycle control protein cyclin D1 and the upregulation of cyclin-dependent kinase inhibitor p21 induced by evodiamine. In conclusion, PPARγ signaling pathway may involve in the proliferation inhibition of evodiamine on K562 cells via inhibiting cylcin D1 and stimulating of p21.

Topics: Anilides; Apoptosis; Cell Cycle; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Gene Expression Regulation, Neoplastic; Humans; K562 Cells; Leukemia; PPAR gamma; Quinazolines

Polydatin (PD), a natural precursor of resveratrol, has a variety of biological activities, including anti‑tumor effects. However, the underlying molecular mechanisms of the anti-cancer activity of PD has not been fully elucidated. The present study demonstrated that PD significantly inhibited the proliferation of the MOLT-4 leukemia cell line in a dose‑ and time-dependent manner by using Cell Counting Kit‑8 assay. PD also dose-dependently increased the apoptotic rate and caused cell cycle arrest in S phase in MOLT‑4 cells, as revealed by flow cytometry. In addition, PD dose-dependently decreased the mitochondrial membrane potential and led to the generation of reactive oxygen species in MOLT-4 cells. Western blot analysis revealed that the expression of anti‑apoptotic protein B-cell lymphoma 2 (Bcl-2) was decreased, whereas that of pro‑apoptotic protein Bcl‑2‑associated X was increased by PD. Furthermore, the expression of two cell cycle regulatory proteins, cyclin D1 and cyclin B1, was suppressed by PD. Of note, the pro‑apoptotic and cell cycle‑inhibitory effects of PD were potentiated by Janus kinase 2 (JAK2) inhibition. In conclusion, the results of the present study strongly suggested that PD is a promising therapeutic compound for the treatment of leukemia, particularly in combination with JAK inhibitors.

Topics: Antineoplastic Agents; Apoptosis; bcl-2-Associated X Protein; Blotting, Western; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Cyclin B1; Cyclin D1; Glucosides; Humans; Janus Kinase 2; Leukemia; Membrane Potential, Mitochondrial; Mitochondria; Proto-Oncogene Proteins c-bcl-2; Reactive Oxygen Species; STAT3 Transcription Factor; Stilbenes

Previous research has shown that total saponins of Panax ginseng (TSPG) and other ginsenoside monomers inhibit the proliferation of leukemia cells. However, the effect has not been compared among them. Cell viability was determined by Cell Counting Kit-8 assay, and ultra-structural characteristics were observed under transmission electron microscopy. Cell cycle distribution and apoptosis were determined by flow cytometry (FCM). Real-time fluorescence quantitative‑PCR, western blotting and immunofluorescence were used to measure the expression of β-catenin, TCF4, cyclin D1 and NF-κBp65. β-catenin/TCF4 target gene transcription were observed by ChIP-PCR assay. We found that 20(S)-ginsenoside Rh2 [(S)Rh2] inhibited the proliferation of KG-1a cells more efficiently than the other monomers. Moreover, (S)Rh2 arrested KG-1a cells in the G0/G1 phase and induced apoptosis. In addition, the levels of β-catenin, TCF4, cyclin D1 mRNA and protein were decreased. The ChIP-PCR showed that (S)Rh2 downregulated the transcription of β-catenin/TCF4 target genes, such as cyclin D1 and c-myc. These results indicated that (S)Rh2 induced cell cycle arrest and apoptosis through the Wnt/β-catenin signaling pathway, demonstrating its potential as a chemotherapeutic agent for leukemia therapy.

Topics: Antineoplastic Agents; Apoptosis; Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; beta Catenin; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Drugs, Chinese Herbal; Flow Cytometry; G1 Phase Cell Cycle Checkpoints; Ginsenosides; Humans; Leukemia; Microscopy, Electron, Transmission; Panax; Real-Time Polymerase Chain Reaction; Transcription Factor 4; Transcription Factor RelA; Transcription Factors; Wnt Proteins; Wnt Signaling Pathway

Serine/threonine protein phosphatase 5 (PPP5C) participates in multiple signaling pathways including cell cycle control and cell growth. PPP5C is involved in the progression of human breast cancer and hepatocellular carcinoma. However, its function in acute myelogenous leukemia (AML) remains unknown. In this study, we constructed a lentivirus system to knock down the expression level of PPP5C in leukemic cell line U937. Cell proliferation and cell cycles were assessed by MTT assay and flow cytometry respectively. Western blot was used to determine the level of caspase-3, PARP (poly ADP-ribose polymerase), CDK4 and CyclinD1. Knockdown of PPP5C suppressed the proliferation ability of U937 cells, and led to G0/G1 phase arrest, inducing cell apoptosis in U937 cells. The apoptosis of the U937 cells was associated with upregulating cleaved caspase-3 and PARP, and downregulating CDK4 and CyclinD1. In conclusions, PPP5C knockdown inhibits U937 cell proliferation and might be used as a potential therapeutic target for the treatment of leukemia.

Topics: Apoptosis; Blotting, Western; Caspase 3; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase 4; Down-Regulation; Flow Cytometry; G1 Phase Cell Cycle Checkpoints; Humans; Leukemia; Nuclear Proteins; Phosphoprotein Phosphatases; Poly(ADP-ribose) Polymerases; Real-Time Polymerase Chain Reaction; RNA Interference; RNA, Small Interfering; U937 Cells

It has recently been shown that JARID2 contributes to the malignant character of solid tumors, such as epithelial-mesenchymal transition in lung and colon cancer cell lines, but its role in leukemia progression is unexplored. In this study, we explored the effect and underlying molecular mechanism of JARID2 on leukemia cell proliferation. Real-time PCR and Western assay were carried out to detect JARID2 and CCND1 expression. Cell number and cell cycle change were detected using hemocytometer and flow cytometry, and a ChIP assay was utilized to investigate JARID2 and H3K27me3 enrichment on the CCND1 promoter. JARID2 is down-regulated in B-chronic lymphocytic leukemia (B-CLL) and acute monocytic leukemia (AMOL), and knockdown of JARID2 promotes leukemia cell proliferation via acceleration of the G1/S transition. Conversely, ectopic expression of JARID2 inhibits these malignant phenotypes. Mechanistic studies show that JARID2 negatively regulates CCND1 expression by increasing H3K27 trimethylation on the CCND1 promoter. Our findings indicate that JARID2 is a negative regulator of leukemia cell proliferation, and functions as potential tumor suppressor in leukemia.

Topics: Adult; Aged; Aged, 80 and over; Animals; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Chromosome Aberrations; Cyclin D1; Disease Models, Animal; Down-Regulation; Female; Gene Expression Regulation, Leukemic; Heterografts; Histones; Humans; Leukemia; Male; Mice; Middle Aged; Polycomb Repressive Complex 2; Tumor Burden; Young Adult

To investigate the effect of ginsenoside Rh2 on leukemia KG1-α cells.. KG1-α cells were cultured in 96-well plate and harvested in the exponential phase. The cells were induced in the presence of different concentrations of Rg1, Rb1, Rh2 respectively for 24, 48, 72 hours. The conventional culture was performed in blank control group, and cytarabine hydrochloride as the positive control. The inhibitory effects of ginsenoside Rb1, Rg1, Rh2 on the growth of KG1-α cells were tested by CCK-8 assay. Then the most efficient ginsenoside was chosen for the further study by IC50. The effects of the ginsenoside Rh2 on cell cycle and apoptosis were detected by flow cytometry (FCM) combined with PI staining and annexin V-FITC/PI, respectively. The expressions of P53, P21, cyclin D1 and cleaved-caspase-3 were examined by Western blotting.. CCK-8 assay results showed that IC50 of ginsenoside Rh2, ginsenoside Rb1, ginsenoside Rg1 and cytarabine were 75, 207, 268, 1058 μmol/L, respectively. Compared with those in blank control group, the KG1-α cells after treated with 75 μmol/L ginsenoside Rh2 showed up-regulated apoptosis rates from (5.37±0.02)% to (8.37±0.015)% at 24 hours and to (33.22±1.67)% at 48 hours (P<0.05). In addition, the percentage of cells in G0/G1 phase increased significantly from (26.78±3.14)% to (29.26±2.31)% at 24 hours and to (44.77±2.26)% at 48 hours, and the percentage in S phase decreased significantly from (65.43±2.22)% to (51.46±0.57)% and (48.29±1.80)%, respectively. The expression levels of cleaved-caspase 3, P53 and P21 proteins went up significantly when the cells were treated with 75 μmol/L Rh2(P<0.05), meanwhile cyclin D1 protein dropped significantly (P<0.05).. Ginsenoside Rh2 could inhibit the proliferation of KG1-α cell and prompt its apoptosis.

Topics: Apoptosis; Blotting, Western; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Dose-Response Relationship, Drug; Drugs, Chinese Herbal; Flow Cytometry; Ginsenosides; Humans; Inhibitory Concentration 50; Leukemia; Time Factors; Tumor Suppressor Protein p53

This study was aimed to analyze the expression profiles of PI3K/AKT signaling pathway genes from bone marrow samples of AML and ALL patients and normal samples. AML, ALL and normal bone marrow samples were collected from 6 AML, 6 ALL patients and 4 normal persons. The expression of PI3K/AKT signaling pathway genes including PTEN, CCND1, mTOR, RICTOR, FOXO1 were detected by real-time fluorescent quantification RT-PCR while GAPDH gene expression was used as an internal reference. The relative gene expression level was calculated by the method of the 2(-ΔΔCt). The results showed that the gene expression profiles were different between normal and leukemic groups. PTEN, mTOR and RICTOR expression levels were down-regulated, while FOXO1 and CCND1 levels were up-regulated in AML and ALL. PTEN was down-regulated in 10 out of the 12 samples; mTOR was down-regulated in 9 out of the 12 samples; RICTOR was down-regulated in 7 out of the 12 samples; FOXO1 was up-regulated in 9 out of the 12 samples and CCND1 was up-regulated in 7 out of the 12 samples. It is concluded that PI3K/AKT signal pathway is activated in both AML and ALL leukemic cells.

Topics: Carrier Proteins; Case-Control Studies; Cyclin D1; Forkhead Box Protein O1; Forkhead Transcription Factors; Gene Expression Regulation, Leukemic; Humans; Leukemia; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Rapamycin-Insensitive Companion of mTOR Protein; RNA, Messenger; Signal Transduction; TOR Serine-Threonine Kinases; Transcriptome

The protein signal transducer and activator of transcription 5 (STAT5) of the JAK/STAT pathway is constitutively activated because of its phosphorylation by tyrosine kinase activity of fusion protein BCR-ABL in chronic myelogenous leukemia (CML) cells. This study investigated the potential therapeutic effect of STAT5 decoy oligodeoxynucleotides (ODN) using leukemia K562 cells as a model. Our results showed that transfection of 21-mer-long STAT5 decoy ODN into K562 cells effectively inhibited cell proliferation and induced cell apoptosis. Further, STAT5 decoy ODN downregulated STAT5 targets bcl-xL, cyclinD1, and c-myc at both mRNA and protein levels in a sequence-specific manner. Collectively, these data demonstrate the therapeutic effect of blocking the STAT5 signal pathway by cis-element decoy for cancer characterized by constitutive STAT5 activation. Thus, our study provides support for STAT5 as a potential target downstream of BCR-ABL for CML treatment and helps establish the concept of targeting STAT5 by decoy ODN as a novel therapy approach for imatinib-resistant CML.

Topics: Apoptosis; Base Sequence; bcl-X Protein; Cell Cycle; Cell Proliferation; Cyclin D1; HL-60 Cells; Humans; K562 Cells; Leukemia; Oligodeoxyribonucleotides; Proto-Oncogene Proteins c-myc; Signal Transduction; STAT5 Transcription Factor; Substrate Specificity; Transcriptional Activation

As one of the main micronutrients in vegetables and fruit carotenoids are almost daily intaken in significant quantity. Although the pharmacological roles of carotenoids in the prevention and reduction of cancer incidence have received more and more attention, the exact molecular mechanisms underlying anticancer effects of carotenoids remain unclear yet. Activated peroxisome proliferator-activated receptor gamma (PPARγ) plays an inhibitory role in cancer cell proliferation and growth. Involvement of PPARγ in the growth inhibition of leukemia K562 cells by carotenoids was investigated in the present study. The results demonstrated that β-carotene, astaxanthin, capsanthin, and bixin inhibited the proliferation and decreased the viability of leukemia K562 cells in dose- and time-dependent manners, induced cell apoptosis, and interfered with cell cycle progression. Pretreatment with GW9662, a potent antagonist of PPARγ, partly attenuated the inhibition of K562 cell proliferation by the four carotenoids at 8μM. These carotenoids up-regulated the expression of PPARγ and p21 and down-regulated the expression of cyclin D1 in a dose-dependent manner. In addition, β-carotene, astaxanthin, capsanthin and bixin also up-regulated the expression of Nrf2, an important transcription factor in Keap1-Nrf2/EpRE/ARE signaling pathway. It appears to us that PPARγ signaling pathways and Keap1-Nrf2/EpRE/ARE signaling pathway were involved in the inhibition of K562 cell proliferation by carotenoids and the up-regulation of PPARγ expression at least partly contributed to the antiproliferative effects of β-carotene, astaxanthin, capsanthin, and bixin on K562 cells.

Topics: Antineoplastic Agents, Phytogenic; Carotenoids; Cell Proliferation; Cell Survival; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Gene Expression Regulation, Leukemic; Humans; K562 Cells; Leukemia; NF-E2-Related Factor 2; PPAR gamma; Up-Regulation

Previous work from our laboratory has confirmed that human ether-à-go-go-related gene 1 (hERG1) K(+) channels are constitutively expressed in leukemia cells and enhanced cell proliferation. More importantly, it has shown that stromal cell-derived factor-1a (SDF-1a) significantly increases hERG1 K(+) tail current and a specific hERG1 K(+) channels inhibitor significantly blocks SDF-1a-induced migration of leukemic cells. In this study, we investigated a possible regulatory effect of hERG1 K(+) channels upon SDF-1a-mediated cell proliferation as a mean to uncover new molecular events involved in bone marrow microenvironment and leukemogenesis. RT-PCR showed that SDF-1a enhanced hERG1 expression in a dose-dependent manner. Cell proliferation assay illustrated that SDF-1a promoted cell proliferation in a dose-dependent manner, whereas this effect was impaired by E-4031. In addition, E-4031 inhibited SDF-1a-stimulated leukemic cell proliferation by inducing G(0)/G(1) arrest. Interestingly, E-4031 promoted SDF-1a-induced apoptosis in HL-60 and leukemic blasts, which markedly impaired the protection effect of SDF-1a in AML. Moreover, SDF-1a increased the expression of Wnt/beta-catenin target genes, including beta-catenin, cyclin-D1, and c-myc; however, this manner was abolished by blockage with the hERG1 K(+) channels. Taken together, our results provide evidence of a novel mechanism involved in the proliferative effects of SDF-1a and highlight hERG1 K(+) channels as a therapeutic target for leukemia treatment and prevention.

Topics: Apoptosis; beta Catenin; Cell Cycle; Cell Proliferation; Chemokine CXCL12; Cyclin D1; Dose-Response Relationship, Drug; Ether-A-Go-Go Potassium Channels; Flow Cytometry; G1 Phase; Gene Expression Regulation, Leukemic; HL-60 Cells; Humans; Leukemia; Leukemia, Myeloid, Acute; Leukocytes, Mononuclear; Piperidines; Proto-Oncogene Proteins c-myc; Pyridines; Resting Phase, Cell Cycle; Reverse Transcriptase Polymerase Chain Reaction

To observe the expression of cyclin D1, hTERT, and telomerase activity in MNC, HL-60, HL-60A and to explore their effects on leukemogenesis and drug-resistance, normal human peripheral blood mononuclear cells, HL-60 cells sensitive to adriamycin and HL-60A cells resistant to adriamycin were investigated. The cell cycle was analyzed by flow cytometry, and the apoptosis was analyzed by Annexin V-FITC(+) PI staining. Expressions of cyclin D1 and hTERT were determined by real-time PCR and Western blot. Telomerase activity was detected by TRAP-ELISA. The results indicated that the percentage of MNC, HL-60 and HL-60A in S phase was (10.21 + 2.11)%, (44.93 + 3.00)%, and (51.38 + 1.10)% respectively; the percentage of apoptosis cells was (16.14 + 2.13)%, (7.53 + 0.92)%, (4.15 + 0.96)% respectively; the expression of mRNA and protein for cyclin D1 and hTERT increased; the telomerase activities of HL-60 and HL-60A were higher (p = 0.000), whereas the difference between HL-60 and HL-60A was no statistically significant (p = 0.232); positive correlation between cyclin D1, hTERT and telomerase activity had been found (p < 0.01). It is concluded that the cells of S phase increased while the apoptotic cells decreased in HL-60 and HL-60A, especially in HL-60A, which may be due to the up-regulation of cyclin D1, hTERT and telomerase activity.

Topics: Cell Cycle; Cyclin D1; HL-60 Cells; Humans; Leukemia; Telomerase

Although the maintenance of HSC quiescence and self-renewal are critical for controlling stem cell pool and transplantation efficiency, the mechanisms by which they are regulated remain largely unknown. Understanding the factors controlling these processes may have important therapeutic potential for BM failure and cancers. Here, we show that Skp2, a component of the Skp2 SCF complex, is an important regulator for HSC quiescence, frequency, and self-renewal capability. Skp2 deficiency displays a marked enhancement of HSC populations through promoting cell cycle entry independently of its role on apoptosis. Surprisingly, Skp2 deficiency in HSCs reduces quiescence and displays increased HSC cycling and proliferation. Importantly, loss of Skp2 not only increases HSC populations and long-term reconstitution ability but also rescues the defect in long-term reconstitution ability of HSCs on PTEN inactivation. Mechanistically, we show that Skp2 deficiency induces Cyclin D1 gene expression, which contributes to an increase in HSC cycling. Finally, we demonstrate that Skp2 deficiency enhances sensitivity of Lin(-) Sca-1(+) c-kit(+) cells and leukemia cells to chemotherapy agents. Our findings show that Skp2 is a novel regulator for HSC quiescence and self-renewal and that targeting Skp2 may have therapeutic implications for BM transplantation and leukemia stem cell treatment.

Topics: Animals; Antineoplastic Agents; Apoptosis; Cell Division; Cyclin D1; Drug Resistance, Neoplasm; Hematopoietic Stem Cell Transplantation; Hematopoietic Stem Cells; Leukemia; Mice; Mice, 129 Strain; Mice, Inbred C57BL; Mice, Mutant Strains; PTEN Phosphohydrolase; S-Phase Kinase-Associated Proteins

The breaking of peripheral T-cell tolerance toward self-antigens expressed by tumor cells and the subsequent establishment of an effective tumor protective immune response remains a major challenge for cancer immunotherapy. We report that both protective and therapeutic anti-tumor immune responses can be achieved in a mouse leukemia/lymphoma tumor model through the strong adjuvant effects provided by allogeneic CD3/CD28 cross-linked Th1 memory cells. The adjuvant effect of these cells is mediated by their ability to produce a variety of 'danger signals' which serve to deviate native non-protective Th2 anti-leukemia immune responses to effective Th1 immune responses.

Topics: Animals; Antigens, Neoplasm; Cancer Vaccines; CD28 Antigens; CD3 Complex; Cell Differentiation; Cyclin D1; Female; Immunologic Memory; Immunotherapy, Active; Leukemia; Lymphoma; Male; Mice; Th1 Cells; Transplantation, Homologous

The cAMP-responsive element binding protein (CREB) is a 43-kDa nuclear transcription factor that regulates cell growth, memory, and glucose homeostasis. We showed previously that CREB is amplified in myeloid leukemia blasts and expressed at higher levels in leukemia stem cells from patients with myeloid leukemia. CREB transgenic mice develop myeloproliferative disease after 1 year, but not leukemia, suggesting that CREB contributes to but is not sufficient for leukemogenesis. Here, we show that CREB is most highly expressed in lineage negative hematopoietic stem cells (HSCs). To understand the role of CREB in hematopoietic progenitors and leukemia cells, we examined the effects of RNA interference (RNAi) to knock down CREB expression in vitro and in vivo. Transduction of primary HSCs or myeloid leukemia cells with lentiviral CREB shRNAs resulted in decreased proliferation of stem cells, cell- cycle abnormalities, and inhibition of CREB transcription. Mice that received transplants of bone marrow transduced with CREB shRNA had decreased committed progenitors compared with control mice. Mice injected with Ba/F3 cells expressing either Bcr-Abl wild-type or T315I mutation with CREB shRNA had delayed leukemic infiltration by bioluminescence imaging and prolonged median survival. Our results suggest that CREB is critical for normal myelopoiesis and leukemia cell proliferation.

Topics: Animals; Cell Line; Cell Proliferation; Cyclic AMP Response Element-Binding Protein; Cyclin A; Cyclin D1; Gene Expression Regulation; Hematopoiesis; Humans; Leukemia; Mice; Mice, Inbred C57BL; RNA Interference; Survival Rate

The objective of the present study was to investigate the effect of trichostatin A (TSA), a histone deacetylase (HDAC) inhibitor, on the cell growth and apoptosis and its effect on the telomerase activity in human leukemic cell line U937. Exposure of U937 cells to TSA resulted in growth inhibition and induction of apoptosis in a dose-dependent manner as measured by hemocytometer counts, fluorescence microscopy, agarose gel electrophoresis and flow cytometry analysis. The increase in apoptosis was associated with the up-regulation in proapoptotic Bax expression and down-regulation of antiapoptotic Bcl-2 and Bcl-X(L). TSA treatment inhibited the levels of cIAP family members and induced the proteolytic activation of caspase-3, which was associated with concomitant degradation of poly(ADP-ribose)-polymerase and beta-catenin protein. TSA treatment markedly inhibited the activity of telomerase in a dose-dependent fashion. Additionally, the expression of human telomerase reverse transcriptase (hTERT), a main determinant of the telomerase enzymatic activity, was progressively down-regulated by TSA treatment. We therefore conclude that TSA demonstrated antiproliferative and apoptosis-inducing effects on U937 cells in vitro, and that changes in Bcl-2 family protein levels as well as telomerase activity may play an important role in its mechanism of action.

Topics: Apoptosis; Blotting, Western; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Dose-Response Relationship, Drug; Electrophoresis, Agar Gel; Enzyme Inhibitors; Flow Cytometry; Histone Deacetylases; Humans; Hydroxamic Acids; Leukemia; Microscopy, Fluorescence; Reverse Transcriptase Polymerase Chain Reaction; Telomerase

Integrated pathways are believed to determine hematopoietic cell fate and/or neoplastic transformation. Notch signaling has been shown to regulate T-cell differentiation and leukemogenesis. However, specific target genes and molecular partners are not fully elucidated. We show that Notch3 activation sustains aberrant SCL/Tal1 overexpression and phosphorylation in mature thymocytes. Furthermore, we define the role of SCL/Tal1 as a component of an activator complex, including phosphorylated Tal1 and Sp1, that specifically enhances cyclin D1 expression and demonstrate that Tal1/Sp1 specifically co-occupy the D1 promoter in vivo, only in the presence of pre-T-cell receptor (TCR). We therefore conclude not only that cyclin D1 is a target of the Tal1/Sp1 complex, but also that Notch3-dependent activation of pre-TCR/ERK signaling regulates SCL/Tal1 function.

Topics: Animals; Basic Helix-Loop-Helix Transcription Factors; Cell Differentiation; Cell Transformation, Neoplastic; Cyclin D1; Extracellular Signal-Regulated MAP Kinases; Gene Expression Regulation, Leukemic; Humans; Leukemia; Mice; Mice, Mutant Strains; Multiprotein Complexes; Neoplasm Proteins; Promoter Regions, Genetic; Proto-Oncogene Proteins; Receptor, Notch3; Receptors, Antigen, T-Cell; Receptors, Notch; Signal Transduction; T-Cell Acute Lymphocytic Leukemia Protein 1; T-Lymphocytes

Notch signaling plays a critical role in T-cell differentiation and leukemogenesis. We previously demonstrated that, while pre-TCR is required for thymocytes proliferation and leukemogenesis, it is dispensable for thymocyte differentiation in Notch3-transgenic mice. Notch3-transgenic premalignant thymocytes and T lymphoma cells overexpress pTalpha/pre-TCR and display constitutive activation of NF-kappaB, providing survival signals for immature thymocytes. We provide genetic and biochemical evidence that Notch3 triggers multiple NF-kappaB activation pathways. A pre-TCR-dependent pathway preferentially activates NF-kappaB via IKKbeta/IKKalpha/NIK complex, resulting in p50/p65 heterodimer nuclear entry and recruitment onto promoters of Cyclin D1, Bcl2-A1 and IL7-receptor-alpha genes. In contrast, upon pTalpha deletion, Notch3 binds IKKalpha and maintains NF-kappaB activation through an alternative pathway, depending on an NIK-independent IKKalpha homodimer activity. The consequent NF-kappaB2/p100 processing allows nuclear translocation of p52/RelB heterodimers, which only trigger transcription from Bcl2-A1 and IL7-receptor-alpha genes. Our data suggest that a finely tuned interplay between Notch3 and pre-TCR pathways converges on regulation of NF-kappaB activity, leading to differential NF-kappaB subunit dimerization that regulates distinct gene clusters involved in either cell differentiation or proliferation/leukemogenesis.

Topics: Animals; Cell Nucleus; Chromatin Immunoprecipitation; Cyclin D1; Electrophoretic Mobility Shift Assay; I-kappa B Kinase; I-kappa B Proteins; Leukemia; Membrane Glycoproteins; Mice; Mice, Transgenic; NF-kappa B; NF-kappa B p52 Subunit; NF-KappaB Inhibitor alpha; NF-kappaB-Inducing Kinase; Protein Serine-Threonine Kinases; Protein Transport; Proto-Oncogene Proteins c-bcl-2; Receptor, Notch3; Receptors, Antigen, T-Cell, alpha-beta; Receptors, Interleukin-7; Receptors, Notch; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; T-Lymphocytes; Thymus Gland; Transcription Factor RelA; Transcription Factor RelB

Haematopoietic stem cells (HSCs) must achieve a balance between quiescence and activation that fulfils immediate demands for haematopoiesis without compromising long-term stem cell maintenance, yet little is known about the molecular events governing this balance. Phosphatase and tensin homologue (PTEN) functions as a negative regulator of the phosphatidylinositol-3-OH kinase (PI(3)K)-Akt pathway, which has crucial roles in cell proliferation, survival, differentiation and migration. Here we show that inactivation of PTEN in bone marrow HSCs causes their short-term expansion, but long-term decline, primarily owing to an enhanced level of HSC activation. PTEN-deficient HSCs engraft normally in recipient mice, but have an impaired ability to sustain haematopoietic reconstitution, reflecting the dysregulation of their cell cycle and decreased retention in the bone marrow niche. Mice with PTEN-mutant bone marrow also have an increased representation of myeloid and T-lymphoid lineages and develop myeloproliferative disorder (MPD). Notably, the cell populations that expand in PTEN mutants match those that become dominant in the acute myeloid/lymphoid leukaemia that develops in the later stages of MPD. Thus, PTEN has essential roles in restricting the activation of HSCs, in lineage fate determination, and in the prevention of leukaemogenesis.

Topics: Animals; Cell Count; Cell Cycle; Cell Lineage; Cell Proliferation; Cyclin D1; Gene Expression; Hematopoietic Stem Cells; Leukemia; Mice; Mutation; PTEN Phosphohydrolase

Interactions between the protein kinase C and Chk1 inhibitor UCN-01 and rapamycin in human leukemia cells have been investigated in relation to apoptosis induction. Treatment of U937 monocytic leukemia cells with rapamycin (10 nmol/L) in conjunction with a minimally toxic concentration of UCN-01 (100 nmol/L) for 36 hours resulted in marked potentiation of mitochondrial injury (i.e., loss of mitochondrial membrane potential and cytosolic release of cytochrome c, AIF, and Smac/DIABLO), caspase activation, and apoptosis. The release of cytochrome c, AIF, and Smac/DIABLO were inhibited by BOC-D-fmk, indicating that their release was caspase dependent. These events were associated with marked down-regulation of Raf-1, MEK, and ERK phosphorylation, diminished Akt activation, and enhanced phosphorylation of c-Jun NH2-terminal kinase (JNK). Coadministration of UCN-01 and rapamycin reduced the expression levels of the antiapoptotic members of the Bcl-2 family Mcl-1 and Bcl-xL and diminished the expression of cyclin D1 and p34(cdc2). Furthermore, enforced expression of a constitutively active MEK1 or, to a lesser extent, myristoylated Akt construct partially but significantly attenuated UCN-01/rapamycin-mediated lethality in both U937 and Jurkat cell systems. Finally, inhibition of the stress-related JNK by SP600125 or by the expression of a dominant-negative mutant of c-Jun significantly attenuated apoptosis induced by rapamycin/UCN-01. Together, these findings indicate that the mammalian target of rapamycin inhibitor potentiates UCN-01 cytotoxicity in a variety of human leukemia cell types and suggest that inhibition of both Raf-1/MEK/ERK and Akt cytoprotective signaling pathways as well as JNK activation contribute to this phenomenon.

Topics: Antibiotics, Antineoplastic; Antineoplastic Agents; Apoptosis; Caspases; CDC2 Protein Kinase; Cell Line, Tumor; Cyclin D1; Cytochromes c; Dose-Response Relationship, Drug; Down-Regulation; Enzyme Activation; Extracellular Signal-Regulated MAP Kinases; Genes, Dominant; Humans; Immunoblotting; JNK Mitogen-Activated Protein Kinases; Jurkat Cells; Leukemia; MAP Kinase Kinase 1; MAP Kinase Kinase 4; Mitogen-Activated Protein Kinase Kinases; Phosphorylation; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-raf; Signal Transduction; Sirolimus; Staurosporine; Time Factors; U937 Cells

Cyclins are very important components of the cell cycle machinery because their levels regulate cell proliferation. They have also been found to be prognostic factors in various cancers. We studied the expression of the positive cell cycle regulators (D cyclins) and the cell proliferation marker (Ki-67) in human acute myeloid (AML), chronic myeloid (CML), acute lymphoblastic (ALL) and chronic lymphocytic (CLL) leukemia [mainly by comparative reverse transcription polymerase chain reaction (RT-PCR)]. Both leukemic and normal cells were positive for cyclin D3 expression. Significant differences were found in the expression of cyclin D1, which was the highest in leukocytes (CD19 + ) of CLL patients whereas lower expression was found in CML, AML and ALL patients and normal bone marrow and peripheral blood leukocytes (P < 0.001). The higher expression of cyclin D1 in leukocytes of CLL patients compared to CML patients was confirmed by quantitative real-time RT-PCR with a TaqMan probe in a subset of CLL and CML patients. Differences in cyclin D1 expression between CLL and CML patients were also confirmed on protein levels by western blotting. Expression of the proliferative marker Ki-67 was high in CML, ALL and AML cells and low in CD19-positive CLL cells. The results demonstrate that the level of cyclin D1 negatively correlates with the proliferation properties of leukemic cells. We did not find any significant relationship between cyclin D1 expression in cells of CML and AML patients and their clinical outcome.

Topics: Acute Disease; Cell Proliferation; Cyclin D1; Cyclin D2; Cyclin D3; Cyclins; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Humans; Ki-67 Antigen; Leukemia; Leukemia, Lymphocytic, Chronic, B-Cell; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Leukemia, Myeloid; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Reverse Transcriptase Polymerase Chain Reaction

Classical t(11;14)(q13;q32) involving IGH-CCND1 is typically associated with aggressive CD5-positive mantle cell lymphoma (MCL). Recently, we identified the IGK variant of this translocation, t(2;11)(p11;q13), in three patients with a leukemic small-cell B-non-Hodgkin lymphoma. In all cases, rearrangements of the IGK and CCND1 genes were demonstrated by fluorescence in situ hybridization. Moreover, we mapped the 11q13 breakpoint of this variant translocation in the 3' region of CCND1 which contrasts with the 5' breakpoints in a standard t(11;14)(q13;q32). Expression of cyclin D1 was shown in two cases analyzed either at diagnosis or during disease progression. All three patients were asymptomatic at presentation and no initial therapy was required. One patient died of a progressive disease 58 months from diagnosis, and two patients showed stable disease after 12 months of follow-up. In two analyzed cases, mutated IGVH genes were identified. Our findings indicate that variant t(2;11)(p11;q13) does not typify a classical MCL but possibly a more indolent leukemic lymphoma originating from an antigen experienced (mutated) B cell.

Topics: Adult; Chromosomes, Human, Pair 11; Chromosomes, Human, Pair 2; Cyclin D1; Disease Progression; DNA, Neoplasm; Female; Gene Rearrangement, B-Lymphocyte, Heavy Chain; Genetic Variation; Humans; Immunoglobulin Heavy Chains; Immunoglobulin Variable Region; Immunoglobulins; In Situ Hybridization, Fluorescence; Karyotyping; Leukemia; Leukemia, Lymphocytic, Chronic, B-Cell; Lymphoma, Mantle-Cell; Lymphoma, Non-Hodgkin; Male; Middle Aged; Mutation; Neoplasm Recurrence, Local; Translocation, Genetic

Mantle-cell lymphoma (MCL) is a B-cell malignancy with distinct molecular genetics and pathological features. Peripheral blood involvement has been reported with variable frequency, but information on the natural history of cases presenting with leukemia is lacking. This study aimed to determine the clinical and prognostic features of such cases. We studied clinical features, tumor characteristics, prognostic factors and outcome in 58 patients with leukemic presentation of MCL. Diagnosis was based on morphology, immunophenotype, presence of t(11;14), histology and cyclin D1 expression. The median age was 62 years and male:female 2.4:1. Presenting features included splenomegaly (74%), lymphadenopathy (45%), hepatomegaly (17%) and, in a minority, gastro-intestinal involvement or involvement of Waldeyer's ring; 10% had lymphocytosis alone. Six patients developed central nervous system disease. Median lymphocyte count was 58 x 10(9)/l, 55% had anemia and 17% had thrombocytopenia. Morphology of peripheral blood showed small-cell MCL in 15% of cases, typical MCL in 46% and blastoid MCL in 39%. Immunological markers showed a typical phenotype (CD5+ CD23 -) in 68%, and atypical phenotypes, CD5- CD23- in 17% or CD5+ CD23+ in 15%. CLL scores were 0, 1 or 2 in 96%. Median overall survival was 36 months. Good response to first-line treatment (P = 0.0008) and splenomegaly (P = 0.03) were favorable prognostic factors, while other features including morphology and CD38 expression had no impact on survival or treatment response. This analysis demonstrates that except for splenomegaly, survival of MCL patients presenting with leukemia is not significantly influenced by clinical or tumor characteristics. Splenectomy is a useful treatment option in this group of patients.

Topics: Adult; Aged; Aged, 80 and over; Biopsy; Cyclin D1; Cytogenetic Analysis; Diagnosis, Differential; Female; Humans; Immunophenotyping; Leukemia; Lymphoma, Mantle-Cell; Male; Middle Aged; Prognosis; Retrospective Studies; Splenectomy; Survival Analysis; Treatment Outcome

The associated poor prognosis and potentially aggressive behavior of mantle cell lymphoma and its blastoid variants make differentiation from other non-Hodgkin B-cell lymphomas especially important. We present a case of mantle cell lymphoma with a marked leukemic component, which demonstrated both a typical nodular mantle cell pattern and Burkitt lymphoma within a single lymph node removed at the time of splenectomy. The presence of CD5, CD10, and Bcl-1 co-expression by immunohistochemistry and detectable t(11;14) and cMYC gene rearrangement by FISH analyses in the Burkitt region support a transformation of mantle cell lymphoma over a concomitant malignancy. A limited number of mantle cell lymphomas demonstrating dual t(11;14) and chromosome 8q24 cMYC gene rearrangements have been previously reported in the literature. They demonstrate an extremely aggressive course with a very poor prognosis. Although the accelerated terminal phase of this patient's clinical course mirrors these previous published cases; none have described the combined morphologic and immunophenotypic features of Burkitt lymphoma reported here. This case provides further support for the aggressive nature of these lymphomas and demonstrates the utility of flow cytometry, immunohistochemistry, and cytogenetic techniques in avoiding potential errors in their diagnosis, prognosis, and treatment.

Topics: Burkitt Lymphoma; Cell Transformation, Viral; Cyclin D1; Female; Gene Rearrangement; Genes, myc; Herpesvirus 4, Human; Humans; Leukemia; Lymph Nodes; Lymphoma, Mantle-Cell; Middle Aged; Splenectomy

The eukaryotic translation initiation factor 4E (eIF4E) acts as both a key translation factor and as a promoter of nucleocytoplasmic transport of specific transcripts. Traditionally, its transformation capacity in vivo is attributed to its role in translation initiation in the cytoplasm. Here, we demonstrate that elevated eIF4E impedes granulocytic and monocytic differentiation. Our subsequent mutagenesis studies indicate that this block is a result of dysregulated eIF4E-dependent mRNA transport. These studies indicate that the RNA transport function of eIF4E could contribute to leukemogenesis. We extended our studies to provide the first evidence that the nuclear transport function of eIF4E contributes to human malignancy, specifically in a subset of acute and chronic myelogenous leukemia patients. We observe an increase in eIF4E-dependent cyclin D1 mRNA transport and a concomitant increase in cyclin D1 protein levels. The aberrant nuclear function of eIF4E is due to abnormally large eIF4E bodies and the loss of regulation by the proline-rich homeodomain PRH. We developed a novel tool to modulate this transport activity. The introduction of IkappaB, the repressor of NF-kappaB, leads to suppression of eIF4E, elevation of PRH, reorganization of eIF4E nuclear bodies, and subsequent downregulation of eIF4E-dependent mRNA transport. Thus, our findings indicate that this nuclear function of eIF4E can contribute to leukemogenesis by promoting growth and by impeding differentiation.

Topics: Active Transport, Cell Nucleus; Base Sequence; Cell Differentiation; Cyclin D1; DNA, Complementary; DNA, Neoplasm; Eukaryotic Initiation Factor-4E; Gene Expression Regulation, Neoplastic; Genes, myc; Hematopoiesis; Homeodomain Proteins; Humans; In Vitro Techniques; Leukemia; NF-kappa B; RNA, Messenger; Transcription Factors

Mantle cell lymphoma is a mature, virgin B-cell neoplasm characterized immunologically by a panB+, CD5+, CD23-, cyclin D1+ phenotype and genetically by t(11;14)(q13;q32) with overexpression of the cyclin D1 (bcl-1) gene. It usually presents as advanced stage disease, involving lymph nodes, spleen, bone marrow, and extranodal sites, particularly the gastrointestinal tract. However, frank leukemic presentation with high white cell counts is uncommon and can be difficult to distinguish from other chronic lymphoproliferative disorders. The aim of this study was to characterize the morphologic spectrum of leukemic mantle cell lymphoma.. During the period July 1994 through October 1998, 14 patients with mantle cell lymphoma in leukemic phase were diagnosed at the Department of Pathology, Queen Elizabeth Hospital, Hong Kong. The diagnosis of mantle cell lymphoma was based on histologic and immunocytochemical findings and was confirmed by cyclin D1 immunoreactivity in all cases. The clinical records and laboratory results were reviewed. Peripheral blood smears, bone marrow, and other tissue biopsies were examined, with particular attention to the cytologic features of the leukemic mantle cells.. Mantle cell lymphoma in leukemic phase showed a very aggressive clinical course. Eight patients died at a mean of 13 months, and only 1 patient was disease free. Morphologically, the leukemic mantle cells exhibited a broad morphologic spectrum, with several cytologic patterns identified: 1) mixed small and medium-sized cells, 2) predominantly medium-sized cells, 3) predominantly large cells, and 4) giant cells. Despite variations in the size and nuclear shape, the leukemic mantle cells could usually be recognized by the nuclear irregularity and clefting, moderately dense but evenly distributed chromatin, small nucleoli, and scant cytoplasm.. Recognition of the characteristic cytologic features of leukemic mantle cells can help to distinguish them from other chronic lymphoproliferative disorders. In contrast to the latter, the clinical course is aggressive and response to conventional chemotherapy is poor.

Topics: Aged; Aged, 80 and over; Bone Marrow Examination; Cyclin D1; Female; Humans; Immunohistochemistry; Immunophenotyping; Leukemia; Lymphoma, Non-Hodgkin; Male; Middle Aged

We observed the expression of wild-type retinoblastoma protein (RB) in all 17 hematologic cultured cell lines tested. However, no p16INK4 expression was detected in any cell line among 16 leukemia/lymphoma cell lines, although an EBV-transformed cell line expressed p16INK4. The expression levels of cyclin D1 and CDK4 varied widely among the cell lines. The correlation coefficient (r2) between doubling time (DT) and cyclin D1 in the 14 cell lines that doubled within 47.2 h was 0.4856, while the r2 between DT and cyclin dependent kinase 4 (CDK4) and that between DT and RB among those cell lines were 0.3761 and 0.0874, respectively. The levels of protein expression in vincristine (VCR)-resistant cell lines was not different from those in corresponding wild-type cell lines. Thus, we concluded that the loss of p16INK4 protein and inactivation of RB protein could be an essential step for oncogenesis of leukemia/ lymphoma, and that cyclin D1 may possibly be a target protein to control cell growth of hematologic cell lines which lack the expression of p16INK4.

Topics: Cell Division; Cyclin D1; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase Inhibitor p16; Cyclin-Dependent Kinases; G1 Phase; Humans; Leukemia; Lymphoma; Proto-Oncogene Proteins; Retinoblastoma Protein; Tumor Cells, Cultured

To investigate the regulatory mechanism of the expression of the multidrug resistance gene (mdr-1) and the multidrug resistance-associated protein gene (mrp), we investigated if p53, WT1, RB, C-myc, N-myc, cyclin D1, p16INK4 (p16) are involved in the acquirement of multidrug resistance phenotype (MDR) in human vincristine (VCR)-resistant cells of leukemia/lymphoma cell lines. By using RT-PCR, we observed that MDR in VCR-resistant cell lines was mediated by either mdr-1 or mrp genes. In cells that acquired the overexpression of mdr-1, downregulation of p53 and upregulation of WT-1 were observed. In contrast, no constant change of genes was observed in cells that overexpressed mrp. Although the change in the expression level of cyclin D1 and p-16 accompanied the development of VCR resistance, the mRNA of RB, C-myc and N-myc showed no correlation with the degree of VCR resistance or the level of mdr-1 expression. These results may provide a plausible diagnostic marker for determination of drug sensitivity in cancer patients and suggest that p53 may mediate directly or indirectly the expression of mdr-1 via WT1 in VCR-resistant hematologic cell lines.

Topics: ATP Binding Cassette Transporter, Subfamily B, Member 1; ATP-Binding Cassette Transporters; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p16; Cytarabine; DNA-Binding Proteins; Doxorubicin; Drug Resistance, Neoplasm; Gene Expression Regulation, Neoplastic; Genes, p53; Genes, Retinoblastoma; Humans; Leukemia; Lymphoma; Multidrug Resistance-Associated Proteins; Proto-Oncogene Proteins c-myc; RNA, Messenger; RNA, Neoplasm; Transcription Factors; Tumor Cells, Cultured; Vincristine; WT1 Proteins

Cell-cycle-dependent phosphorylation of the tumor-suppressor protein product of the retinoblastoma gene (RB) is mediated by a family of cyclin-dependent kinases and cyclins. We examined the expressions of RB protein and cyclin A protein in 13 small-cell lung cancer (SCLC) lines and 14 non-small-cell lung cancer (NSCLC) lines by immunoblotting. RB protein was not present or was of a mutant type in 77% of the SCLC lines (10/13) but was present in all the NSCLC lines. Cyclin A was expressed in 38% of the SCLC lines (5/13) and in 86% of the NSCLC lines (12/14). A positive correlation (P = 0.0034) between expression of cyclin A and wild-type RB protein was found by Fisher's exact probability test. Densitometric analysis of the expression of RB protein in RB(+) lung cancer lines showed that the phosphorylated form was predominant in 2/3 of the SCLC and 8/14 of the NSCLC lines. The positive correlation between the expressions of RB protein and cyclin A suggests that RB protein in most RB(+) lung cancer cell lines is a target of cyclin-A-dependent kinase and that the tumor-suppressor function may be inactivated by phosphorylation.

Topics: Adenovirus E1A Proteins; Blotting, Western; Carcinoma, Non-Small-Cell Lung; Carcinoma, Small Cell; Cyclin A; Cyclin D1; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase Inhibitor p16; Cyclin-Dependent Kinases; Humans; Leukemia; Lung Neoplasms; Phosphorylation; Proto-Oncogene Proteins; Retinoblastoma Protein; Tumor Cells, Cultured

Approximately 70% of centrocytic (mantle-cell) lymphomas have the chromosomal translocation t(11;14) (q13; q32) and associated rearrangements at the bcl-1 breakpoint locus and at the cyclin D1 (PRAD1, CCND1) gene, thus implicating this gene in the pathogenesis of centrocytic lymphoma. In order to determine cyclin D1 expression in hematopoietic neoplasms with and without bcl-1 or cyclin D1 rearrangements, northern blot analysis was performed.. Total RNA was isolated from peripheral blood cells of patients with hematopoietic neoplasms in leukemic phase, including three patients with B-cell lymphoma containing chromosome 11q13 bcl-1 rearrangements. Northern blots were hybridized with a cyclin D1 cDNA probe and the degree of mRNA expression determined.. Each of the bcl-1-rearranged cases showed high levels of cyclin D1 expression, whereas no expression was detected in RNA from samples of B-cell CLL, T-cell prolymphocytic leukemia, or acute nonlymphocytic leukemia which lacked bcl-1 or cyclin D1 rearrangement.. Overexpression of cyclin D1, a G1 cyclin implicated in cell-cycle regulation, may play a critical role in the pathogenesis of t(11; 14)-positive lymphomas.

Topics: Blotting, Northern; Chromosomes, Human, Pair 11; Cyclin D1; Cyclins; Gene Expression; Gene Rearrangement; Humans; Leukemia; Lymphoma, Non-Hodgkin; Oncogene Proteins; Translocation, Genetic

Rearrangement and overexpression of CCND1 (BCL1/PRAD1), a member of the cyclin G1 gene family, are consistent features of t(11q13)-bearing B-lymphoid tumors (particularly mantle-cell lymphoma [MCL]). Its deregulation is thought to perturb the G1-S transition of the cell cycle and thereby to contribute to tumor development. As suggested by previously published studies, rearrangement of the 3' untranslated region (3' UTR) of CCND1 may contribute to its activation in some lymphoid tumors. To define further the prevalence of such rearrangements, we report here the result of the molecular study of 34 MCL and six t(11q13)-associated leukemias using a set of probes specific to the different parts of the CCND1 transcript. We also sequenced the entire cDNA of the overexpressed CCND1 transcripts in a t(11q13)-associated leukemia. DNA from four of these 40 patients showed rearrangement of the 3' UTR of CCND1 coexisting with major translocation cluster (MTC) rearrangement. Southern blot and sequence analyses showed that, as a result of these rearrangements, the 3' AU-rich region containing sequences involved in mRNA stability and in translational control is eliminated. Moreover, the finding that the CCND1 mRNA half-life was greater than 3 hours (normal tissues, 0.5 hours) in three t(11q13)-associated cell lines stresses the importance of posttranscriptional derangement in the activation of CCND1. Finally, we did not observe any mutation in the coding frame of the CCND1 cDNA analyzed.

Topics: Amino Acid Sequence; Base Sequence; Chromosomes, Human, Pair 11; Cyclin D1; Cyclins; Gene Rearrangement; Humans; Leukemia; Lymphoma, Non-Hodgkin; Molecular Sequence Data; Oncogene Proteins; Proto-Oncogene Proteins; Proto-Oncogenes; RNA, Messenger; Translocation, Genetic