cyclin-d1 and Leukemia--Myeloid--Acute

Disorders of the cell cycle regulatory machinery play a key role in the pathogenesis of cancer. Over expression of cyclin D1 protein has been reported in several solid tumors and certain lymphoid malignancies, but little is known about the involvement of cyclin D1 in acute leukemia.. In this study, we analyzed the expression of cyclin D1 at protein level in, 40 newly diagnosed patients with acute myeloid leukemia (AML), 10 patients with acute lymphoblastic leukemia (ALL), and 11 normal controls using flow cytometry.. The expression of cyclin D1 was not significantly different in AML group as compared to normal controls. On the other hand, over expression of cyclin D1 was evident in ALL group (4/10) as compared to that in healthy control. The ALL cases with cyclin D1 over expression were significantly correlated to blast cell counts in the peripheral blood and bone marrow (BM) but not with hemoglobin level, WBC, and platelets count. The ALL group with lymphadenopathy and organomegaly express significantly higher cyclin D1 over expression as compared to those without.. The biological value of cyclin D1 over expression might be different in AML and ALL.

Topics: Adult; Biomarkers, Tumor; Bone Marrow; Cyclin D1; Female; Gene Expression Regulation, Leukemic; Humans; Leukemia, Myeloid, Acute; Male; Middle Aged; Precursor Cell Lymphoblastic Leukemia-Lymphoma

Aberrant expression of ecotropic viral integration site-1 (EVI1+) is associated with very poor outcomes in acute myeloid leukemia (AML), mechanisms of which are only partially understood. Using the green fluorescent protein reporter system to monitor EVI1 promoter activity, we demonstrated that Evi1high KMT2A-MLLT1-transformed AML cells possess distinct features from Evi1low cells: the potential for aggressive disease independent of stem cell activity and resistance to cytotoxic chemotherapy, along with the consistent gene expression profiles. RNA sequencing and chromatin immunoprecipitation sequencing in EVI1-transformed AML cells and normal hematopoietic cells combined with functional screening by cell proliferation-related short hairpin RNAs revealed that the erythroblast transformation-specific transcription factor ERG (E26 transformation-specific [ETS]-related gene) and cyclin D1 were downstream targets and therapeutic vulnerabilities of EVI1+ AML. Silencing Erg in murine EVI1+ AML models severely impaired cell proliferation, chemoresistance, and leukemogenic capacity. Cyclin D1 is also requisite for efficient EVI1-AML development, associated with gene expression profiles related to chemokine production and interferon signature, and T- and natural killer-cell exhaustion phenotype, depending on the interferon gamma (IFN-γ)/STAT1 pathway but not on CDK4/CDK6. Inhibiting the IFN-γ/STAT1 pathway alleviated immune exhaustion and impaired EVI1-AML development. Overexpression of EVI1 and cyclin D1 was associated with IFN-γ signature and increased expression of chemokines, with increased exhaustion molecules in T cells also in human AML data sets. These data collectively suggest that ERG and cyclin D1 play pivotal roles in the biology of EVI1+ AML, where ERG contributes to aggressive disease nature and chemoresistance, and cyclin D1 leads to IFN-γ signature and exhausted T-cell phenotypes, which could potentially be targeted.

Topics: Animals; Cyclin D1; DNA-Binding Proteins; Humans; Leukemia, Myeloid, Acute; MDS1 and EVI1 Complex Locus Protein; Mice; Proto-Oncogenes; Transcription Factors; Transcriptional Regulator ERG

Acute myeloid leukemia (AML) is a common hematological malignancy. Circular RNAs (circRNAs) are newly discovered endogenous non-coding RNAs that play important roles in regulating gene expression in cancer biology. The aim of this study was to identify novel prognostic and therapeutic targets associated with AML.. The expression levels of circRNA Plexin B2 (circPLXNB2), microRNA-654-3p (miR-654-3p) and cyclin D1 protein (. CircPLXNB2 was highly expressed in AML patients and cells, and circPLXNB2 was more stable than linear PLXNB2. Knockdown of circPLXNB2 affected the proliferation, apoptosis and cell cycle distribution of AML cells. CircPLXNB2 acted as a sponge for miR-654-3p and affected the progression of AML cells by targeting miR-654-3p.. In conclusion, circPLXNB2 was highly expressed in AML patients and cells and modulated tumor progression by regulating the circPLXNB2/miR-654-3p/

Topics: Apoptosis; Blotting, Western; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Humans; Leukemia, Myeloid, Acute; MicroRNAs

Transient Receptor Potential Melastatin Subfamily Member 4 (TRPM4) has been demonstrated to be aberrantly expressed in several cancers but seldom reported in acute leukemia. Based on database mining and validated experiments, our present data show that TRPM4 is selectively overexpressed in AML patients and cell lines with the MLL gene rearrangement. We analyzed the correlation between TRPM4 expression and clinical parameters in a validated cohort of AML patients. Increased TRPM4 expression was associated with significant leukocytosis (p = .028), M4/M5 subtype (p = .000), FLT3-ITD mutation (p = .034), MLL status (p = .007) and a higher risk stratification (p = .001). Knockdown of TRPM4 mediated by siRNA impaired proliferation and arrested the cell cycle at the G0/G1 phase in MLL-rearranged leukemia cells. We suggested that TRPM4 may be involved in the pathogenesis of MLL-rearranged leukemia through regulating the AKT/GLI1/Cyclin D1 pathway. The transcription factor HOXA9 was found to be responsible for upregulation of TRPM4 expression by binding to its promoter. In conclusion, TRPM4 is overexpressed in MLL-rearranged AML and blockade of TRPM4 may be an alternative therapeutic approach in AML patients with high TRPM4 expression.

Topics: Adult; Case-Control Studies; Cell Cycle; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Female; Gene Expression Regulation, Neoplastic; Gene Rearrangement; Histone-Lysine N-Methyltransferase; Homeodomain Proteins; Humans; Leukemia, Myeloid, Acute; Male; Middle Aged; Myeloid-Lymphoid Leukemia Protein; Promoter Regions, Genetic; Proto-Oncogene Proteins c-akt; Signal Transduction; Transcription, Genetic; TRPM Cation Channels; Up-Regulation; Zinc Finger Protein GLI1

Long non-coding RNA taurine upregulated gene 1 (lncRNA TUG1) has been demonstrated to promote malignant phenotypes and Adriamycin resistance in acute myeloid leukemia (AML) cells. However, the function and mechanism of TUG1 in cytarabine (Ara-C) sensitivity in AML remain unclear.. Levels of TUG1, microRNA (miR)-655-3p or cyclin D1 (CCND1) mRNA were examined using quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation activity and apoptosis were analyzed using cell counting kit-8 (CCK-8) or flow cytometry, respectively. Western blot was utilized to detect the protein levels of Ki-67, B-cell lymphoma-2-associated X protein (Bax), and CCND1. The interaction between miR-655-3p and TUG1 or CCND1 was confirmed by Dual-Luciferase reporter and pull-down assay.. TUG1 and CCND1 were higher expressed, while miR-655-3p was lower expressed in AML cells compared with that in normal cells. Higher expression levels of TUG1 or CCND1, and lower expression levels of miR-655-3p both notably reversed Ara-C-induced proliferation inhibition and apoptosis promotion in AML cells. TUG1 was a sponge of miR-655-3p, and TUG1 knockdown enhanced the sensitivity of AML cells to Ara-C by regulating miR-655-3p. MiR-655-3p directly targeted CCND1, and CCND1 overexpression attenuated miR-655-3p restoration-mediated reinforcement of Ara-C sensitivity in AML cells. Besides that, TUG1 up-regulated CCND1 expression via miR-655-3p.. TUG1 weakened the sensitivity of AML cells to Ara-C by up-regulating CCND1 via miR-655-3p, suggesting a new insight into the chemotherapy of AML.

Topics: Antimetabolites, Antineoplastic; Apoptosis; Cell Proliferation; Cells, Cultured; Cyclin D1; Cytarabine; Humans; Leukemia, Myeloid, Acute; MicroRNAs; RNA, Long Noncoding

The AML1-ETO oncoprotein, which results from t(8;21) translocation, is considered an initial event of t(8;21) acute myeloid leukemia (AML). However, the precise mechanisms of the oncogenic activity of AML1-ETO is yet to be fully determined. The present study demonstrates that AML1-ETO triggers the heterochromatic silencing of microRNA-564 (miR564) by binding at the AML1 binding site along the miR564 promoter region and recruiting chromatin-remodeling enzymes. Suppression of miR564 enhances the oncogenic activity of the AML1-ETO oncoprotein by directly inhibiting the expression of CCND1 and the DNMT3A genes. Ectopic expression of miR564 can induce retardation of G1/S transition, reperform differentiation, promote apoptosis, as well as inhibit the proliferation and colony formation of AML1-ETO+ leukemia cells in vitro. Enhanced miR564 levels can significantly inhibit the tumor proliferation of t(8;21)AML in vivo. We first identify an unexpected and important epigenetic circuitry of AML1-ETO/miR564/CCND1/DNMT3A that contributes to the leukemogenesis in vitro/vivo of AML1-ETO+ leukemia, indicating that miR564 enhancement could provide a potential therapeutic method for AML1-ETO+ leukemia.

Topics: Animals; Apoptosis; Base Sequence; Carcinogenesis; Cell Cycle Checkpoints; Cell Differentiation; Cell Line, Tumor; Core Binding Factor Alpha 2 Subunit; Cyclin D1; DNA (Cytosine-5-)-Methyltransferases; DNA Methylation; DNA Methyltransferase 3A; Epigenesis, Genetic; Female; Gene Expression Regulation, Leukemic; Gene Silencing; Humans; Leukemia, Myeloid, Acute; Mice, Inbred BALB C; Mice, Nude; MicroRNAs; Oncogene Proteins, Fusion; Promoter Regions, Genetic; Protein Binding; RUNX1 Translocation Partner 1 Protein; Translocation, Genetic; Up-Regulation

Pediatric acute myeloid leukemia (AML) is a complex and heterogeneous disease. Several studies have shown the regulatory functions of microRNAs (miRNAs) in pediatric AML progression, and in this study, we aimed to evaluate the biological role of miR-206 in pediatric AML. The results demonstrated that miR-206 expression levels in the bone marrow and serum of pediatric AML patients were remarkably decreased than those in normal controls, and low serum miR-206 expression was closely associated with the unfavorable clinicopathological characteristics and prognosis of pediatric AML patients. In addition, in vitro functional experiments revealed that overexpression of miR-206 significantly inhibited AML cell proliferation partly through induction of cell cycle arrest. Further studies showed that Cyclin D1 might be a direct target of miR-206 in AML cells, and the impaired proliferation ability of miR-206-overexpressing AML cells was notably rescued by Cyclin D1 restoration. Accordingly, the findings of our study suggested that miR-206 might serve as a promising prognostic marker and a potential therapy target for patients with pediatric AML.

Topics: Biomarkers, Tumor; Bone Marrow; Cell Cycle; Cell Cycle Checkpoints; Cell Proliferation; Child; Child, Preschool; Cyclin D1; Disease Progression; Female; Genes, Tumor Suppressor; Humans; Leukemia, Myeloid, Acute; Male; MicroRNAs; Prognosis

Cancer is a hyper-proliferative disease. Whether the proliferative state originates from the cell-of-origin or emerges later remains difficult to resolve. By tracking de novo transformation from normal hematopoietic progenitors expressing an acute myeloid leukemia (AML) oncogene MLL-AF9, we reveal that the cell cycle rate heterogeneity among granulocyte-macrophage progenitors (GMPs) determines their probability of transformation. A fast cell cycle intrinsic to these progenitors provide permissiveness for transformation, with the fastest cycling 3% GMPs acquiring malignancy with near certainty. Molecularly, we propose that MLL-AF9 preserves gene expression of the cellular states in which it is expressed. As such, when expressed in the naturally-existing, rapidly-cycling immature myeloid progenitors, this cell state becomes perpetuated, yielding malignancy. In humans, high CCND1 expression predicts worse prognosis for MLL fusion AMLs. Our work elucidates one of the earliest steps toward malignancy and suggests that modifying the cycling state of the cell-of-origin could be a preventative approach against malignancy.

Topics: Animals; Cell Cycle; Cell Differentiation; Cell Proliferation; Cell Transformation, Neoplastic; Cyclin D1; Disease Models, Animal; Female; Gene Expression Regulation, Leukemic; Gene Knock-In Techniques; Humans; Kaplan-Meier Estimate; Leukemia, Myeloid, Acute; Male; Mice, Transgenic; Myeloid Progenitor Cells; Myeloid-Lymphoid Leukemia Protein; Oncogene Proteins, Fusion; Piperazines; Primary Cell Culture; Prognosis; Pyridines

Aberrant activation of Wnt/β-catenin signaling pathway is essential for the development of AML; however, the mechanistic basis for this dysregulation is unclear. PRL-3 is an oncogenic phosphatase implicated in the development of LSCs. Here, we identified Leo1 as a direct and specific substrate of PRL-3. Serine-dephosphorylated form of Leo1 binds directly to β-catenin, promoting the nuclear accumulation of β-catenin and transactivation of TCF/LEF downstream target genes such as cyclin D1 and c-myc. Importantly, overexpression of PRL-3 in AML cells displayed enhanced sensitivity towards β-catenin inhibition in vitro and in vivo, suggesting that these cells are addicted to β-catenin signaling. Altogether, our study revealed a novel regulatory role of PRL-3 in the sustenance of aberrant β-catenin signaling in AML. PRL-3 may serve as a biomarker to select for the subset of AML patients who are likely to benefit from treatment with β-catenin inhibitors. Our study presents a new avenue of cancer inhibition driven by PRL-3 overexpression or β-catenin hyperactivation.

Topics: Animals; beta Catenin; Cyclin D1; Gene Expression Regulation, Neoplastic; Humans; Leukemia, Myeloid, Acute; Mice; Neoplasm Proteins; Protein Binding; Protein Tyrosine Phosphatases; Proto-Oncogene Proteins c-myc; Transcription Factors; Wnt Proteins; Wnt Signaling Pathway; Xenograft Model Antitumor Assays

Leukemia-initiating cells (LICs) are responsible for the initiation, development, and relapse of leukemia. The identification of novel therapeutic LIC targets is critical to curing leukemia. In this report, we reveal that junctional adhesion molecule 3 (JAM3) is highly enriched in both mouse and human LICs. Leukemogenesis is almost completely abrogated upon Jam3 deletion during serial transplantations in an MLL-AF9-induced murine acute myeloid leukemia model. In contrast, Jam3 deletion does not affect the functions of mouse hematopoietic stem cells. Moreover, knockdown of JAM3 leads to a dramatic decrease in the proliferation of both human leukemia cell lines and primary LICs. JAM3 directly associates with LRP5 to activate the downstream PDK1/AKT pathway, followed by the downregulation of GSK3β and activation of β-catenin/CCND1 signaling, to maintain the self-renewal ability and cell cycle entry of LICs. Thus, JAM3 may serve as a functional LIC marker and play an important role in the maintenance of LIC stemness through unexpected LRP5/PDK1/AKT/GSK3β/β-catenin/CCND1 signaling pathways but not via its canonical role in cell junctions and migration. JAM3 may be an ideal therapeutic target for the eradication of LICs without influencing normal hematopoiesis.

Topics: Animals; beta Catenin; Cell Adhesion Molecules; Cyclin D1; Hematopoiesis; Hematopoietic Stem Cells; Immunoglobulins; Leukemia, Myeloid, Acute; Low Density Lipoprotein Receptor-Related Protein-5; Mice; Mice, Inbred NOD; Mice, Knockout; Mice, SCID; Proto-Oncogene Proteins c-akt; Signal Transduction

Chemokine (C-C motif) ligand 2 (CCL2) is a member of the CC subfamily, which displays chemotactic activity for monocytes and basophils. This molecule plays a very important role in many solid tumors and shows changes in the bone marrow microenvironment. However, its role in acute myeloid leukaemia (AML) is still unclear.. In this study, we established a HL-60 cell line with CCL2 knockdown to explore its effect on leukemogenesis. Lentivirus with CCL2-knockdown was successfully constructed after screening effective CCL2 short hairpin RNA (shRNA) sequences and was transfected into HL-60 cells, which was further validated at the mRNA and protein levels by real-time polymerase chain reaction (PCR) and Western blotting, respectively.. Low expression of CCL2 significantly decreased HL-60 cell growth by increasing the cell arrest at G1 phase by 12% more than controls. We applied RNA sequencing technology to discriminate the gene expression profiles between the cells with CCL2 knockdown and the controls, and Cyclin D1 was selected for further experiments as its expression level was significantly downregulated, which was validated at the mRNA and protein levels. Cyclin D1 knockdown experiments showed that the cell proliferation rate was evidently decelerated, and cell cycle analysis also indicated a similar pattern for CCL2.. Our study revealed that Cyclin D1 is an effector that mediates CCL2's function in cell proliferation by blocking cells at G1 phase.

Topics: Cell Line, Tumor; Cell Proliferation; Chemokine CCL2; Cyclin D1; HL-60 Cells; Humans; Leukemia, Myeloid, Acute

Accumulating evidence suggests that dysregulation of Dishevelled-Axin domain-containing 1 (DIXDC1) is involved in the progression and development of various cancers. However, little is known about the relevance of DIXDC1 in acute myeloid leukemia (AML). In this study, we aimed to investigate the expression status and potential biological function of DIXDC1 in AML. Our results showed that DIXDC1 expression was highly upregulated in AML cell lines and primary AML blasts compared with normal blasts. Knockdown of DIXDC1 by siRNA-mediated gene silencing significantly inhibited proliferation, induced cell cycle arrest, and promoted apoptosis of AML cells in vitro. By contrast, DIXDC1 overexpression promoted proliferation, accelerated cell cycle progression, and reduced apoptosis of AML cells. Moreover, we found that DIXDC1 knockdown decreased the expression of β-catenin and restricted the activation of Wnt signaling. In addition, DIXDC1 knockdown decreased the expression of Wnt/β-catenin target genes, including cyclin D1 and c-myc, while DIXDC1 overexpression had the opposite effect. Notably, β-catenin knockdown partially reversed the oncogenic effect of DIXDC1 in AML cells. Taken together, these results demonstrate that DIXDC1 promotes the growth of AML cells, possibly through upregulating the Wnt/β-catenin signaling pathway. Our study suggests that DIXDC1 may serve as a potential therapeutic target for the treatment of AML.

Topics: Apoptosis; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Gene Silencing; Humans; Intracellular Signaling Peptides and Proteins; Leukemia, Myeloid, Acute; Microfilament Proteins; Proto-Oncogene Proteins c-myc; RNA, Small Interfering; Up-Regulation; Wnt Signaling Pathway

Core-binding factor acute myeloid leukemia (CBF-AML) is defined by the presence of either t(8;21)(q22;q22)/RUNX1-RUNX1T1 or inv(16)(p13.1q22)/t(16;16)(p13.1;q22)/CBFB-MYH11. The resulting fusion genes require a 'second hit' to initiate leukemogenesis. Mutation assessment of 177 adults with CBF-AML, including 68 with t(8;21) and 109 with inv(16)/t(16;16), identified not only mutations well known in CBF-AML but also mutations in the CCND1 and CCND2 genes, which represent novel frequent molecular alterations in AML with t(8;21). Altogether, CCND1 (n=2) and CCND2 (n=8) mutations were detected in 10 (15%) patients with t(8;21) in our cohort. A single CCND2 mutation was also found in 1 (0.9%) patient with inv(16). In contrast, CCND1 and CCND2 mutations were detected in only 11 (0.77%) of 1426 non-CBF-AML patients. All CCND2 mutations cluster around the highly conserved amino-acid residue threonine 280 (Thr280). We show that Thr280Ala-mutated CCND2 leads to increased phosphorylation of the retinoblastoma protein, thereby causing significant cell cycle changes and increased proliferation of AML cell lines. The identification of CCND1 and CCND2 mutations as frequent mutational events in t(8;21) AML may provide further justification for cell cycle-directed therapy in this disease.

Topics: Adolescent; Adult; Aged; Biomarkers, Tumor; Chromosomes, Human, Pair 21; Chromosomes, Human, Pair 8; Cyclin D1; Cyclin D2; Female; Follow-Up Studies; Humans; Leukemia, Myeloid, Acute; Male; Middle Aged; Mutation; Neoplasm Staging; Prognosis; Survival Rate; Translocation, Genetic; Young Adult

CXCR4 is a key player in the retention and survival of human acute myeloid leukemia (AML) blasts in the bone marrow (BM) microenvironment. We studied the effects of the CXCR4 antagonist BL-8040 on the survival of AML blasts, and investigated the molecular mechanisms by which CXCR4 signaling inhibition leads to leukemic cell death. Treatment with BL-8040 induced the robust mobilization of AML blasts from the BM. In addition, AML cells exposed to BL-8040 underwent differentiation. Furthermore, BL-8040 induced the apoptosis of AML cells in vitro and in vivo. This apoptosis was mediated by the upregulation of miR-15a/miR-16-1, resulting in downregulation of the target genes BCL-2, MCL-1 and cyclin-D1. Overexpression of miR-15a/miR-16-1 directly induced leukemic cell death. BL-8040-induced apoptosis was also mediated by the inhibition of survival signals via the AKT/ERK pathways. Importantly, treatment with a BCL-2 inhibitor induced apoptosis and act together with BL-8040 to enhance cell death. BL-8040 also synergized with FLT3 inhibitors to induce AML cell death. Importantly, this combined treatment prolonged the survival of tumor-bearing mice and reduced minimal residual disease in vivo. Our results provide a rationale to test combination therapies employing BL-8040 and BCL-2 or FLT3 inhibitors to achieve increased efficacy of these agents.

Topics: Apoptosis; Cell Line, Tumor; Cyclin D1; Down-Regulation; Extracellular Signal-Regulated MAP Kinases; Humans; Leukemia, Myeloid, Acute; MicroRNAs; Myeloid Cell Leukemia Sequence 1 Protein; Peptides; Proto-Oncogene Proteins c-bcl-2; Real-Time Polymerase Chain Reaction; Receptors, CXCR4

Acute myelogenous leukemia (AML) is a cancer of the blood that most commonly affects human adults. The specific cause of AML is unclear, but it induces abnormality of white blood cells that grow rapidly and accumulate in bone marrow interfering with the production and functions of the normal blood cells. AML patients face poor prognosis and low quality of life during chemotherapy or transplantation of hematopoietic stem cells due to the progressive impairment of their immune system. The goal of this study is to find natural products that have the potential to delay growth or eliminate the abnormal leukemic cells but cause less harmful effect to the body's immune system.. The unsaponified fraction of Riceberry rice bran (RBDS) and the main pure compound, gramisterol, were studied for cytotoxicity and biological activities in WEHI-3 cells and in the leukemic mouse model induced by transplantation of WEHI-3 cells intraperitoneally. In the in vitro assay, RBDS and gramisterol exerted sub-G1 phase cell cycle arrest with a potent induction of apoptosis. Both of them effectively decreased cell cycle controlling proteins (cyclin D1 and cyclin E), suppressed cellular DNA synthesis and mitotic division, and reduced anti-apoptosis Bcl-2 protein, but increased apoptotic proteins (p53 and Bax) and activated caspase-3 enzyme in the intrinsic cell death stimulation pathway. In leukemic mice, daily feeding of RBDS significantly increased the amount of immune function-related cells including CD3+, CD19+, and CD11b+, and elevated the serum levels of IFN-γ, TNF-α, IL-2, and IL-12β cytokines, but suppressed IL-10 level. At the tumor sites, CD11b+ cells were polarized and became active phagocytotic cells. Treatment of mice normal immune cells with gramisterol alone or a combination of gramisterol with cytokines released from RBDS-treated leukemic mice splenocytes culture synergistically increased pSTAT1 transcriptional factor that up-regulated the genes controlling cell survival and function. Phosphorylation of STAT1 was absent in WEHI-3. Instead, similar treatments significantly decreased pSTAT3 signaling that regulates transcription of genes controlling tumor growth and proliferation.. Rice bran gramisterol possesses a promising anti-cancer effect against a tumor of white blood cells and induces the production of anti-cancer immune-related cytokines. Gramisterol induces cell cycle arrest and apoptosis via suppression of pSTAT3 signaling control of tumor cells' growth and progression. Gramisterol increased IFN-γ production and prevented the dysfunctional immune system of leukemic mice by enhancing pSTAT1 transcription signal controlling proliferation and functions of hematopoietic cells in the spleen. Together with IFN-γ, gramisterol efficiently facilitates leukemic mice immune system modulation leading to improvement of the AML condition. Administration of RBDS containing gramisterol potentiates immune recovery of leukemic mice and extends their survival. This finding encourages the medicinal application of rice bran gramisterol as a palliative treatment or an alternative agent for future drug development against AML.

Topics: Animals; Antigens, CD19; Antineoplastic Agents; Apoptosis; bcl-2-Associated X Protein; Caspase 3; CD11b Antigen; CD3 Complex; Cell Proliferation; Cholestadienols; Cyclin D1; Cyclin E; Disease Models, Animal; Drug Screening Assays, Antitumor; G1 Phase; Gene Expression Regulation, Leukemic; Immune System; Leukemia, Myeloid, Acute; Mice; Mice, Inbred BALB C; Oryza; Plant Extracts; Proto-Oncogene Proteins c-bcl-2; Signal Transduction; Sterols; Tumor Suppressor Protein p53

δ-Tocopherol (δ-T), the least prevalent tocopherol in our diet, was described to have a more potent anticancer activity in solid tumors compared to the other tocopherols. δ-T induces tumor cell death through peroxisome proliferator-activated receptor γ (PPAR-γ) induction, cyclin-D1 inhibition, and modulation of redox balance. Nevertheless, the role of δ-T in preventing or treating hematologic malignancies has not been studied. In this study, we screened the efficacy of δ-T against six cell lines representing a wide spectrum of hematologic malignancies: Jurkat (acute T-cell leukemia), K-562 (chronic myeloid leukemia), KG-1 [acute myeloid leukemia (AML)], THP-1 (acute monocytic leukemia), TOM-1 (acute lymphoblastic leukemia), and UMCL01-101 (AIDS-associated diffuse large B-cell lymphoma). Interestingly, the AML cell line KG-1 was the only one to be significantly affected at concentrations of δ-T as low as 20 µM. The antileukemic activity of δ-T in AML was verified in a set of primary cells collected from patients newly diagnosed with AML. Apoptotic induction and cell cycle arrest explained the efficacy of δ-T against KG-1 cells. The mechanism of cell growth inhibition of δ-T was through downregulation of cyclin-D1 and a set of homeobox proteins (HOXA9, PBX1, and Cdx2) that have a well-documented role in the pathobiology of AML.

Topics: Antineoplastic Agents; Cell Line, Tumor; Cell Survival; Cyclin D1; Homeodomain Proteins; Humans; Jurkat Cells; Leukemia, Myeloid, Acute; Tocopherols

Myogenic enhancer factor2 (Mef2) consists of a family of transcription factors involved in morphogenesis of skeletal, cardiac and smooth muscle cells. Among the four isoforms (Mef2A, 2B, 2C, and 2D), Mef2C was also found to play important roles in hematopoiesis. At myeloid progenitor level, Mef2C expression favors monocytic differentiation. Previous studies from our laboratory demonstrated that ERK5 was activated in 1,25-dihydroxyvitamin D3 (1,25D)-induced monocytic differentiation in AML cells and ERK5 activation was accompanied by increased Mef2C phosphorylation. We therefore examined the role of Mef2C in 1,25D-induced monocytic differentiation in AML cell lines (HL60, U937 and THP1) and found that knockdown of Mef2C with small interfering RNA (siRNA) significantly decreases the expression of the monocytic marker, CD14, without affecting the expression of the general myeloid marker, CD11b. CCAAT/enhancer-binding protein (C/EBP) β, which can bind to CD14 promoter and increase its transcription, has been shown to be the downstream effector of 1,25D-induced monocytic differentiation in AML cells. When Mef2C was knocked down, expression of C/EBPβ was reduced at both mRNA and protein levels. The protein expression levels of cell cycle regulators, p27(Kip1) and cyclin D1, were not affected by Mef2C knockdown, nor the monopoiesis related transcription factor, ATF2 (activating transcription factor 2). Thus, we conclude that 1,25D-induced monocytic differentiation, and CD14 expression in particular, are mediated through activation of ERK5-Mef2C-C/EBPβ signaling pathway, and that Mef2C does not seem to modulate cell cycle progression.

Topics: Apoptosis; Blotting, Western; Calcitriol; CCAAT-Enhancer-Binding Protein-beta; Cell Differentiation; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p27; Flow Cytometry; Gene Expression Regulation, Neoplastic; Humans; Leukemia, Myeloid, Acute; MEF2 Transcription Factors; Monocytes; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tumor Cells, Cultured; Vitamins

Janus kinase (JAK) inhibitors are a promising treatment strategy in several hematological malignancies and autoimmune diseases. A number of inhibitors are in clinical development, and two have already reached the market. Unfortunately, all of them are burdened with different toxicity profiles. To check if the JAK inhibitors of different selectivity evoke different responses on JAK2-dependent and independent cells, we have used three acute myeloid leukemia cell lines with confirmed JAK2 mutation status. We have found that JAK inhibitors exert distinct effect on the expression of BCLXL, CCND1 and c-MYC genes, regulated by JAK pathway, in JAK2 wild type cells in comparison to JAK2 V617F-positive cell lines. Moreover, cell cycle analysis showed that inhibitors alter the cycle by arresting cells in different phases. Our results suggest that observed effect of JAK2 inhibitors on transcription and cell cycle level in different cell lines are associated not with activity within JAK family, but presumably with other off-target activities.

Topics: bcl-X Protein; Cell Cycle; Cell Line, Tumor; Cyclin D1; Down-Regulation; Gene Expression; Humans; Imidazoles; Janus Kinases; Leukemia, Myeloid, Acute; Nitriles; Piperidines; Protein Kinase Inhibitors; Pyrazoles; Pyridazines; Pyrimidines; Pyrroles; Pyrrolidines; Sulfonamides

Internal tandem duplication of FMS-like tyrosine kinase (FLT3-ITD) is well known to be involved in acute myeloid leukemia (AML) progression, but FLT3-ITD-negative AML cases account for 70% to 80% of AML, and the mechanisms underlying their pathology remain unclear. This study identifies protein tyrosine phophatase PRL-3 as a key mediator of FLT3-ITD-negative AML.. A total of 112 FLT3-ITD-negative AML patients were sampled between 2010 and 2013, and the occurrence of PRL-3 hyperexpression in FLT3-ITD-negative AML was evaluated by multivariate probit regression analysis. Overexpression or depletion of endogenous PRL-3 expression with the specific small interfering RNAs was performed to investigate the role of PRL-3 in AML progression. Xenograft models were also used to confirm the oncogenic role of PRL-3.. Compared to healthy donors, PRL-3 is upregulated more than 3-fold in 40.2% of FLT3-ITD-negative AML patients. PRL-3 expression level is adversely correlated to the overall survival of the AML patients, and the AML relapses accompany with re-upregulation of PRL-3. Mechanistically, aberrant PRL-3 expression promoted cell cycle progression and enhanced the antiapoptotic machinery of AML cells to drug cytotoxicity through downregulation of p21 and upregulation of Cyclin D1 and CDK2 and activation of STAT5 and AKT. Depletion of endogenous PRL-3 sensitizes AML cells to therapeutic drugs, concomitant with apoptosis by upregulation of cleaved PARP (poly ADP ribose polymerase) and apoptosis-related caspases. Xenograft assays further confirmed PRL-3's oncogenic role in leukemogenesis.. Our results demonstrated that PRL-3 is a novel independent crucial player in both FLT3-ITD-positive and FLT3-ITD-negative AML and could be a potential therapeutic target.

Topics: Adolescent; Adult; Aged; Animals; Apoptosis; Cell Cycle; Cyclin D1; Cyclin-Dependent Kinase 2; Cyclin-Dependent Kinase Inhibitor p21; Down-Regulation; Female; fms-Like Tyrosine Kinase 3; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Heterografts; Humans; Leukemia, Myeloid, Acute; Male; Mice; Mice, Nude; Middle Aged; Neoplasm Proteins; Protein Tyrosine Phosphatases; Proto-Oncogene Proteins c-akt; STAT5 Transcription Factor; Transcriptional Activation; Up-Regulation; Young Adult

Less than a third of adults patients with acute myeloid leukemia (AML) are cured by current treatments, emphasizing the need for new approaches to therapy. We previously demonstrated that besides playing a role in drug-resistant leukemia cell lines, multidrug resistance protein 4 (MRP4/ABCC4) regulates leukemia cell proliferation and differentiation through the endogenous MRP4/ABCC4 substrate, cAMP. Here, we studied the role of MRP4/ABCC4 in tumor progression in a mouse xenograft model and in leukemic stem cells (LSCs) differentiation. We found a decrease in the mitotic index and an increase in the apoptotic index associated with the inhibition of tumor growth when mice were treated with rolipram (PDE4 inhibitor) and/or probenecid (MRPs inhibitor). Genetic silencing and pharmacologic inhibition of MRP4 reduced tumor growth. Furthermore, MRP4 knockdown induced cell cycle arrest and apoptosis in vivo. Interestingly, when LSC population was isolated, we observed that increased cAMP levels and MRP4/ABCC4 blockade resulted in LSCs differentiation. Taken together, our findings show that MRP4/ABCC4 has a relevant role in tumor growth and apoptosis and in the eradication of LSCs, providing the basis for a novel promising target in AML therapy.

Topics: Animals; Apoptosis; Cell Cycle Checkpoints; Cell Differentiation; Cell Line, Tumor; Cell Proliferation; Cyclic AMP; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Disease Progression; Female; Humans; Leukemia, Myeloid, Acute; Mice; Mice, Nude; Mitotic Index; Multidrug Resistance-Associated Proteins; Neoplasm Transplantation; Neoplastic Stem Cells; Phosphodiesterase 4 Inhibitors; RNA Interference; RNA, Small Interfering; Rolipram; Transplantation, Heterologous

The S component (LukS-PV) is one of the two components of Panton-Valentine leukocidin (PVL), which is a pore-forming cytotoxin secreted by Staphylococcus aureus, with the ability to lyse leukocytes. In this study, LukS-PV had the ability to induce apoptosis in the human acute myeloid leukemia (AML) cell line THP-1. Therefore, we investigated the mechanisms of LukS-PV-induced apoptosis in THP-1 cells. THP-1 cells treated with LukS-PV, resulted in a significant inhibition of proliferation in a dose- and time-dependent manner, and induced G0/G1 arrest associated with an inhibition of cell cycle arrest regulatory protein (cyclin D1) in a dose- and time-dependent manner, as measured by flow cytometry (FCM). After 12h exposure to LukS-PV (1.00 μM), annexin V-EGFP/propidium iodide (PI) FCM revealed that 19.5±3.6% of THP-1 cells were apoptotic, and terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) staining also revealed THP-1 cells were apoptotic. Chip analysis of 84 apoptosis-related genes demonstrated that 9 genes were up-regulated at least 2-fold and that 5 genes were down-regulated at least 2-fold in the treatment group when compared with levels in the control group. Western blotting reveled that the expression of caspase-8 increased significantly (approximately 4-fold). The levels of caspase-9, -3 and Bax increased significantly, and levels of Bcl-2 decreased rapidly with LukS-PV treatment. These data suggest that LukS-PV acts as an anti-leukemia agent and activates AML cell apoptosis via the mitochondrial pathway. Therefore, LukS-PV may be a multi-targeting drug candidate for the prevention and therapy of AML.

Topics: Apoptosis; Bacterial Toxins; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Drug Screening Assays, Antitumor; Exotoxins; G1 Phase Cell Cycle Checkpoints; Gene Expression Profiling; Gene Expression Regulation, Leukemic; Humans; In Situ Nick-End Labeling; Leukemia, Myeloid, Acute; Leukocidins; Mitochondria; Models, Biological; Resting Phase, Cell Cycle; Signal Transduction

t(8;21) is one of the most frequent chromosomal translocations occurring in acute myeloid leukemia (AML) and is considered the leukemia-initiating event. The biologic and clinical significance of microRNA dysregulation associated with AML1/ETO expressed in t(8;21) AML is unknown. Here, we show that AML1/ETO triggers the heterochromatic silencing of microRNA-193a (miR-193a) by binding at AML1-binding sites and recruiting chromatin-remodeling enzymes. Suppression of miR-193a expands the oncogenic activity of the fusion protein AML-ETO, because miR-193a represses the expression of multiple target genes, such as AML1/ETO, DNMT3a, HDAC3, KIT, CCND1, and MDM2 directly, and increases PTEN indirectly. Enhanced miR-193a levels induce G(1) arrest, apoptosis, and restore leukemic cell differentiation. Our study identifies miR-193a and PTEN as targets for AML1/ETO and provides evidence that links the epigenetic silencing of tumor suppressor genes miR-193a and PTEN to differentiation block of myeloid precursors. Our results indicated a feedback circuitry involving miR-193a and AML1/ETO/DNMTs/HDACs, cooperating with the PTEN/PI3K signaling pathway and contributing to leukemogenesis in vitro and in vivo, which can be successfully targeted by pharmacologic disruption of the AML1/ETO/DNMTs/HDACs complex or enhancement of miR-193a in t(8;21)-leukemias.

Topics: Animals; Core Binding Factor Alpha 2 Subunit; Cyclin D1; DNA (Cytosine-5-)-Methyltransferases; DNA Methyltransferase 3A; Down-Regulation; Epigenesis, Genetic; Gene Expression Regulation, Leukemic; Gene Silencing; Histone Deacetylases; HL-60 Cells; Humans; Leukemia, Myeloid, Acute; Mice; Mice, Nude; MicroRNAs; Myelopoiesis; Neoplasm Transplantation; Oncogene Proteins, Fusion; Phosphatidylinositol 3-Kinases; Protein Binding; Proto-Oncogene Proteins c-kit; Proto-Oncogene Proteins c-mdm2; PTEN Phosphohydrolase; RUNX1 Translocation Partner 1 Protein; Signal Transduction; U937 Cells

FMS-like tyrosine kinase 3 (FLT3) is an independent poor prognostic marker of acute myeloid leukemia (AML), and strategies that specifically target FLT3 are therefore of substantial interest. However, previous studies with FLT3 inhibitors as single agents in patients with AML showed few clinical responses. In the present study, combined effects of FLT3 selective inhibitor (SC-203048) and NF-κB selective inhibitor (Parthenolide, PTL) on AML xenograft tumor growth in vivo were examined, and the possible antitumor mechanisms by which SC-203048 and PTL affect AML xenograft tumor growth were also detected. Results showed that the tumor growth was strongly inhibited, and increased cell apoptosis was also observed after treatments, especially in the combination group; meanwhile, the expressions of FLT3, p65, cyclin D1, and Bc1-2 decreased significantly, and the expression of nuclear Silencing mediator for retinoic acid and thyroid hormone receptors (SMRT) increased notably. All results indicate that synergism exists between FLT3 and NF-κB inhibitors, and inhibitors combination treatment may be a potential strategy for AML.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Benzamides; Cell Line, Tumor; Cyclin D1; fms-Like Tyrosine Kinase 3; Humans; Leukemia, Myeloid, Acute; Male; Mice; Mice, Inbred BALB C; Mice, Nude; NF-kappa B; Nuclear Receptor Co-Repressor 2; Proto-Oncogene Proteins c-bcl-2; Sesquiterpenes; Thiophenes; Tumor Burden; Xenograft Model Antitumor Assays

To determine whether mTORC2 and rapamycin-insensitive (RI)-mTORC1 complexes are present in acute myeloid leukemia (AML) cells and to examine the effects of dual mTORC2/mTORC1 inhibition on primitive AML leukemic progenitors.. Combinations of different experimental approaches were used, including immunoblotting to detect phosphorylated/activated forms of elements of the mTOR pathway in leukemic cell lines and primary AML blasts; cell-proliferation assays; direct assessment of mRNA translation in polysomal fractions of leukemic cells; and clonogenic assays in methylcellulose to evaluate leukemic progenitor-colony formation.. mTORC2 complexes are active in AML cells and play critical roles in leukemogenesis. RI-mTORC1 complexes are also formed and regulate the activity of the translational repressor 4E-BP1 in AML cells. OSI-027 blocks mTORC1 and mTORC2 activities and suppresses mRNA translation of cyclin D1 and other genes that mediate proliferative responses in AML cells. Moreover, OSI-027 acts as a potent suppressor of primitive leukemic precursors from AML patients and is much more effective than rapamycin in eliciting antileukemic effects in vitro.. Dual targeting of mTORC2 and mTORC1 results in potent suppressive effects on primitive leukemic progenitors from AML patients. Inhibition of the mTOR catalytic site with OSI-027 results in suppression of both mTORC2 and RI-mTORC1 complexes and elicits much more potent antileukemic responses than selective mTORC1 targeting with rapamycin.

Topics: Antibiotics, Antineoplastic; Apoptosis Regulatory Proteins; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Dose-Response Relationship, Drug; Gene Expression Regulation, Leukemic; HL-60 Cells; Humans; Leukemia, Myeloid, Acute; Mechanistic Target of Rapamycin Complex 1; Multiprotein Complexes; Neoplastic Stem Cells; Oncogene Protein v-akt; Phosphorylation; Proteins; Ribosomal Protein S6 Kinases, 70-kDa; RNA-Binding Proteins; Sirolimus; TOR Serine-Threonine Kinases; Transcription Factors; U937 Cells

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

This study investigated the effect of using small interfering RNA (siRNA) to silence the wild-type FMS-like tyrosine kinase 3 (FLT3) gene in acute myeloid leukaemia (AML) cells, in vitro and in vivo. FLT3 siRNA was introduced into the human AML cell line, THP1, and into a THP1 xenograft tumour model in BALB/c nude mice. FLT3 siRNA effectively reduced both the mRNA and the protein levels of FLT3, arrested cells in G(0)/G(1) phase, inhibited THP1 cell proliferation and increased apoptosis. Intraperitoneal injection of FLT3 siRNA suppressed tumour growth in BALB/c nude mice. FLT3 siRNA treatment also reduced cyclin D1 and Bcl-2 protein levels, and increased the nuclear level of silencing mediator for retinoic acid and thyroid hormone receptors protein both in vitro and in vivo. These data suggest that FLT3 siRNA is a strong inhibitor of FLT3 expression in vitro and in vivo, and may provide a new therapeutic target for AML.

Topics: Animals; Apoptosis; Cell Line, Tumor; Cell Proliferation; Cyclin D1; fms-Like Tyrosine Kinase 3; Gene Expression; Gene Knockdown Techniques; Humans; Leukemia, Myeloid, Acute; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Transplantation; Nuclear Receptor Co-Repressor 2; Proto-Oncogene Proteins c-bcl-2; RNA Interference; RNA, Small Interfering; Tumor Burden

Wnt5a is a member of the Wnt family of proteins that signals through the non-canonical Wnt/Ca(2+)pathway to suppress cyclin D1. Deregulation of this pathway has been found in animal models suggesting that it acts as tumour suppressor in acute myeloid leukemia (AML). Although DNA methylation is the main mechanism of regulation of the canonical Wnt pathway in AML, the role of WNT5A abnormalities has never been evaluated in this clinical setting. The methylation status of WNT5A promoter-exon 1 was analyzed by methylation-specific PCR and sequencing in eleven AML-derived cell lines and 252 AML patients. We observed WNT5A hypermethylation in seven cell lines and in 43% (107/252) of AML patients. WNT5A methylation was associated with decreased WNT5A expression (P < 0.001) that was restored after exposure to 5-Aza-2'-deoxycytidine. Moreover, WNT5A hypermethylation correlated with upregulation of CYCLIN D1 expression (P < 0.001). Relapse (15%vs 37%, P < 0.001) and mortality (61%vs 79%, P = 0.004) rates were lower for patients in the non-methylated group. Disease-free survival and overall survival at 6 and 7 years, respectively, were 60% and 27% for unmethylated patients and 20% and 0% for hypermethylated patients (P = 0.0001 and P = 0.04, respectively). Interestingly, significant differences were also observed when the analysis was carried out according to cytogenetic risk groups. We demonstrate that WNT5A, a putative tumor suppressor gene in AML, is silenced by methylation in this disease and that this epigenetic event is associated with upregulation of CYCLIN D1 expression and confers poor prognosis in patients with AML.

Topics: Adult; Aged; Cyclin D1; DNA Methylation; Epigenesis, Genetic; Female; Humans; Leukemia, Myeloid, Acute; Male; Middle Aged; Promoter Regions, Genetic; Proto-Oncogene Proteins; Signal Transduction; Wnt Proteins; Wnt-5a Protein

This study was aimed to quantitatively detect the levels of beta-catenin and cyclin D1 mRNA in various subgroups of acute myeloid leukemia (AML) and to analyze their potential relationship, so as to provide theoretical basis for exploring the role of Wnt/beta-catenin pathway in the pathogenesis of AML. Real time fluorescent quantitative RT-PCR was used to detect the relative expression levels of beta-catenin and cyclin D1 mRNA, to analyze changes of the two gene expressions and their relationship. The results showed that the beta-catenin mRNA expression level in BMMNC of AML patients was significantly higher than that in benign blood disease patients (p < 0.05), but no statistical difference was found among the various subgroups of AML (p > 0.05). In AML there was overexpression of cyclin D1 mRNA, and its expression level was significantly higher than that in benign blood disease group (p < 0.05), but there was no statistical difference among the subtypes of AML. The expression levels of beta-catenin and cyclin D1 were correlated each other in AML-M(1), M(2) and M(4) (r values were 0.822, 0.627, 0.712 respectively; p values were 0.001, 0.020, 0.002 respectively). It is concluded that the over-expressions of beta-catenin and cyclin D1 exit in AML patients, and the significant correlation appears in part of the subgroups, which means that the Wnt/beta-catenin pathway is aberrantly activated in AML, probably activating the downstream target gene cyclin D1 and participating in the regulation of cell cycle disturbance and abnormal proliferation of leukemic cells.

Topics: Adult; beta Catenin; Cyclin D1; Female; Humans; Leukemia, Myeloid, Acute; Male; RNA, Messenger; Signal Transduction; Young Adult

The t(11;14)(q13;q32) is a hallmark of mantle cell lymphoma. It has been found less frequently in other lymphoproliferative disorders, such as B-prolymphocytic leukemia, plasma cell leukemia, chronic lymphocytic leukemia, and multiple myeloma. Here, we describe a patient with acute myeloid leukemia (AML), categorized as M5b according to French-American-British classification, in which conventional cytogenetic analysis revealed a karyotype with t(11;14)(q13;q32). Fluorescence in situ hybridization analyses demonstrated no rearrangement of the immunoglobulin heavy-chain (IGH) (14q32) locus as well as of the cyclin D1 (CCND1) gene, suggesting that this is not the typical t(11;14) resulting from the CCND1/IGH fusion. The changes in the 11q13 region have been described in both myeloid and lymphoid neoplasm with different chromosomes serving as donors in translocation, but to the best of our knowledge, never with the chromosome 14.

Topics: Bone Marrow; Cyclin D1; Female; Humans; Immunoglobulin Heavy Chains; Karyotyping; Leukemia, Myeloid, Acute; Middle Aged; Translocation, Genetic

D-cyclins are regulators of cell division that act in a complex with cyclin-dependent kinases to commit cells to a program of DNA replication. D-cyclins are overexpressed in many tumors, including multiple myeloma and leukemia, and contribute to disease progression and chemoresistance. To better understand the role and impact of D-cyclins in hematologic malignancies, we conducted a high throughput screen for inhibitors of the cyclin D2 promoter and identified the drug cyproheptadine. In myeloma and leukemia cells, cyproheptadine decreased expression of cyclins D1, D2, and D3 and arrested these cells in the G(0)/G(1) phase. After D-cyclin suppression, cyproheptadine induced apoptosis in myeloma and leukemia cell lines and primary patient samples preferentially over normal hematopoietic cells. In mouse models of myeloma and leukemia, cyproheptadine inhibited tumor growth without significant toxicity. Cyproheptadine-induced apoptosis was preceded by activation of the mitochondrial pathway of caspase activation and was independent of the drug's known activity as an H1 histamine and serotonin receptor antagonist. Thus, cyproheptadine represents a lead for a novel therapeutic agent for the treatment of malignancy. Because the drug is well tolerated and already approved in multiple countries for clinical use as an antihistamine and appetite stimulant, it could be moved directly into clinical trials for cancer.

Topics: Animals; Apoptosis; Cell Line; Cell Line, Tumor; Cyclin D1; Cyclin D2; Cyclin D3; Cyclins; Cyproheptadine; Drug Screening Assays, Antitumor; Gene Expression Regulation; Humans; Leukemia, Myeloid, Acute; Mice; Multiple Myeloma

We report a case of acute myeloid leukemia (AML) subtype M2, with t(5;11)(q35;q13), in a 30-year-old man. Conventional cytogenetic, spectral karyotyping, and fluorescence in situ hybridization (FISH) studies on bone marrow sample obtained at diagnosis revealed an abnormal karyotype in all cells examined. FISH analysis demonstrated absence of translocations in the region of the cyclin D1 gene and real-time quantitative reverse transcriptase-polymerase chain reaction revealed normal expression of this gene. Similar to the 11q23 region, 11q13 changes can be found in both myeloid and lymphoid neoplasias with different chromosomes serving as donors in translocations.

Topics: Adult; Chromosomes, Human, Pair 11; Chromosomes, Human, Pair 5; Cyclin D1; Gene Expression Regulation, Neoplastic; Humans; Leukemia, Myeloid, Acute; Leukemia, Myelomonocytic, Acute; Male; Translocation, Genetic

The effects of valproate and butyrate were investigated in an acute myeloblastic cell line (OCI/AML-2) on cytotoxicity, cell cycle profile and expression of cell cycle regulating proteins in the presence of cytarabine (Ara-C) and etoposide. As a single agent valproate and butyrate inhibited AML cell growth but did not significantly induce cell death. A dramatic increase in cytotoxicity was observed when combining valproate or butyrate with Ara-C, whereas, co-addition of them with etoposide had much smaller effect on cell death. Valproate induced a clear G1 phase arrest and up-regulated cyclin D1 expression in the presence of Ara-C and etoposide. In addition, valporate was able to block the Ara-C-induced down-regulation of p27(Kip1) expression but not that induced by etoposide.

Topics: Butyrates; Cell Cycle; Cell Death; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p27; Cytarabine; Enzyme Inhibitors; Etoposide; Histone Deacetylase Inhibitors; Humans; Leukemia, Myeloid, Acute; Valproic Acid

To determine the expression of cyclin D1 gene in patients with acute leukemia and evaluate the relationship between cyclin D1 expression and treatment outcomes.. The expression of cyclin D1 mRNA was determined in bone marrow cells from 65 acute leukemia patients and 5 normal subjects by RT-PCR technique.. Cyclin D1 mRNA was negative in normal bone marrow cells. Among leukemia patients, the rate of cyclin D1 expression was 26.2%, and the highest(63.6%) rate was in the relapse group and the lowest(8.3%) in the CR group. Relapse rate of the patients with cyclin D1 expression was higher than that of those with negative expression over 1-13 months follow-up.. Overexpression of cyclin D1 does exist in acute leukemia patients and is correlated with the disease progression, especially with relapse.

Topics: Adolescent; Adult; Aged; Bone Marrow Cells; Cyclin D1; Female; Humans; Leukemia, Myeloid, Acute; Male; Middle Aged; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Recurrence; RNA, Messenger