Proteosome Inhibitor Treatment Down-Regulates S-Phase Kinase-Associated Protein 2 Causing Inhibition of Proliferation and Induces Apoptosis in Primary Effusion Lymphoma.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4616-4616
Author(s):  
Azhar R. Hussain ◽  
Naif A. Al-Jomah ◽  
Mehar Sultana ◽  
Manugaran S. Pulicat ◽  
Khawla S. Al-Kuraya ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Lines ◽  
Primary Effusion Lymphoma ◽  
S Phase ◽  
Dependent Manner ◽  
Down Regulation ◽  
Inhibition Of Proliferation ◽  
Dose Dependent ◽  
Inhibitor Treatment

Abstract Proteosome inhibition is a novel approach for treating malignancy and has been approved for clinical use. The proteosome is the primary proteolytic mechanism in eukaryotic cells and inhibition of its catalytic activity initiates a cascade of events affecting cell cycle and apoptotic activities. These activities ultimately lead to cell cycle arrest and apoptosis in malignant cells however, the normal counterpart of these cells are spared. In this study, we used a panel of primary effusion lymphoma cell lines (BC1, BC3, BCBL1 and HBL6) to study the effects of proteosome inhibitor, MG132 on cell proliferation and apoptosis. Our data showed that proteosome inhibitor MG132 decreased cell viability as well as induced apoptosis in a dose dependent manner ranging from 0.5–10μM. Furthermore, treatment with 2.5μM MG132 for 24hours induced 41% apoptosis in BC1, 51% in BC3, 41% in BCBL1 and 48% in HBL6 cell lines as detected by annexinV/PI dual staining. S-phase kinase-associated protein 2 (skp-2) is a proto-oncogene and over expressed in various types of tumors. We sought to determine the role of Skp-2 following proteosome inhibition in PELs. MG132 treatment of PEL cell lines resulted in down-regulation of SKP-2 protein in a dose dependent manner whereas the expression of p-27 was up-regulated demonstrating an inverse relationship between these two proteins. Furthermore, MG132 treatment of PELs led to conformational changes in Bax protein and translocation to the mitochondria leading to the loss of mitochondrial membrane potential with subsequent release of cytochrome c from mitochondria into cytosol. Cytochrome c release caused activation of caspase-3 followed by polyadenosin-5′-diphosphate-ribose polymerase (PARP) cleavage. In addition, proteosome inhibitor treatment also caused down-regulation of inhibitor of apoptosis protein, XIAP. Taken together, our findings show that proteosome inhibition causes down-regulation of skp-2, up-regulation of p-27, inhibition of proliferation as well as caspase-dependent apoptosis in primary effusion lymphoma cells suggesting a role of proteosome inhibitors in the treatment of these aggressive cancers.

Topotecan Induces -Apoptosis in the Myelodysplastic Syndromes Cell Line MUTZ-1 That Is Associated with down Regulation of IAP Expression.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4713-4713
Author(s):  
Zhen Cai ◽  
Wenjun Wu Master
Keyword(s):  
Cell Cycle ◽  
Myelodysplastic Syndromes ◽  
S Phase ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Dna Ladder ◽  
Down Regulation ◽  
Transmission Electron ◽  
Induced Apoptosis ◽  
Dose Dependent

Abstract Myelodysplastic syndromes (MDS) represent a heterogenous group of clonal stem cell disorders with qualitative and quantitative abnormalities of blood cells and a high probability of evolving to acute leukemia. Intensive induction chemotherapy in order to reduce the malignant clone and reconstruct normal hematopoiesis is a classic therapy of MDS, especially high risk MDS. Topotecan (TPT), a semisynthetic water-soluble derivative of camptothecin, is a potent inhibitor of DNA topoisomerase I and has been extensively studied in hematologic malignances. However, little is known about how TPT acts against neoplastic cells. The aim of this study is to evaluate apoptotic effect of TPT on the MDS cell line MUTZ-1 and its associated changes in the expression of inhibitors of apoptosis protein (IAPs). The effect of TPT on MUTZ-1 growth was determined by using MTT assay. Characteristics associated with apoptosis induced by TPT were evaluated by transmission electron microscope, DNA gel electrophoresis and flow cytometry (FCM). Cell cycle shift were observed by FCM. Semi-quantitative RT-PCR was used to evaluate the mRNA expression of members of IAP gene family, including survivin, XIAP, Bcl-2, Bax, cIAP1 andcIAP2. The potential of mitochondrial membrane potential (MMP) was determined by using JC-1 probe. The results demonstrated that TPT significantly inhibited MUTZ-1 cell growth in a time- and dose-dependent manner with IC50 of 5.011 mmol/L, 1.297mmol/L and 0.483mmol/L at 24h, 48h and 72h respectively. Morphological features associated with TPT-induced apoptosis observed by transmission electron microscopy included cytoplasmic and nuclear shrinkage, karyorrhexis, nuclear convolution, chromatin condensation and margination, cytoplasmic vacuolization, and membrane-bound apoptotic bodies. An ambiguous DNA ladder was observed following treatment with 5mmol/L TPT for 24h, and a typical DNA ladder was observed with 10mmol/L TPT for 24h. The apoptotic rates were 11.69±0.51%, 34.07±1.73%, and 48.59±2.01%, respectively, after 24h culture with TPT as 1, 5, 10 μmol/L, significantly higher than that of the control (3.47%±0.3%; F=31.642, P<0.01). The percentage of MUTZ-1 cells in G2/M phase of the cell cycle decreased while in S and G0/G1 phase increased after treatment with 1mmol/L TPT for 24h,. The majority of the cells were arrested in S phase. After 24h culture with TPT at1, 5, and 10μmol/L, the mRNA levels of survivin, XIAP, cIAP1 and cIAP2 were decreased (P<0.01). This down-regulation was negatively correlated with TPT-induced apoptotic rates(P<0.05). There was no significant change in the Bax and Bcl-2 mRNA levels after TPT treatment (P>0.05). After 24h culture with 1μmol/L TPT, the MMP of TPT treated cells decreased significantly(P<0.01). Together, we conclude TPT can inhibit the growth and induce apoptosis of MUTZ-1 cells in a time- and dose- dependent manner. TPT can also induce the cell cycle changes, with the majoritoy of cells being arrested in S phase. The TPT-induced apoptosis in MUTZ-1 cells is associated with down-regulation of suvivin, XIAP, cIAP1and cIAP2 mRNA expresison. As well, MMP may be play a important role in the apoptotic process of MUTZ-1 cells induced by TPT.

scholarly journals B-myb antisense oligonucleotides inhibit proliferation of human hematopoietic cell lines

Blood ◽  
1992 ◽  
Vol 79 (10) ◽  
pp. 2708-2716 ◽  
Author(s):  
M Arsura ◽  
M Introna ◽  
F Passerini ◽  
A Mantovani ◽  
J Golay
Keyword(s):  
Cell Lines ◽  
Antisense Oligonucleotides ◽  
Hematopoietic Cell ◽  
Dependent Manner ◽  
Myb Gene ◽  
Myb Genes ◽  
Dose Dependent ◽  
Lymphoid Cell Lines ◽  
Hematopoietic Cell Lines

Abstract The B-myb gene is highly homologous to the c-myb protooncogene in several domains and also shares some of the functions of c-myb in that it can act as a transcriptional activator. In addition, the expression of both the B-myb and c-myb genes correlates with proliferation of normal hematopoietic cells. We investigated more directly the role of B- myb in proliferation of hematopoietic cell lines using B-myb-specific antisense oligonucleotides. We showed that several anti-B-myb oligonucleotides, complementary to distinct regions of the gene, inhibit significantly and in a dose-dependent manner the proliferation of all myeloid or lymphoid cell lines tested. This block in proliferation was not accompanied by detectable differentiation of U937 or HL60 cells to macrophages or granulocytes either spontaneously or after exposure to chemical agents. These data suggest that the B-myb gene, like c-myb, is necessary for hematopoietic cell proliferation.

scholarly journals Inhibition of Wnt/β-Catenin Signaling in Neuroendocrine Tumors In Vitro: Antitumoral Effects

Cancers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 345
Author(s):  
Xi-Feng Jin ◽  
Gerald Spöttl ◽  
Julian Maurer ◽  
Svenja Nölting ◽  
Christoph Josef Auernhammer
Keyword(s):  
Cell Cycle ◽  
Cell Viability ◽  
Cell Lines ◽  
Neuroendocrine Tumors ◽  
Density Lipoprotein ◽  
Time Dependent ◽  
Dependent Manner ◽  
Antitumor Properties

Background and aims: Inhibition of Wnt/β-catenin signaling by specific inhibitors is currently being investigated as an antitumoral strategy for various cancers. The role of Wnt/β-catenin signaling in neuroendocrine tumors still needs to be further investigated. Methods: This study investigated the antitumor activity of the porcupine (PORCN) inhibitor WNT974 and the β-catenin inhibitor PRI-724 in human neuroendocrine tumor (NET) cell lines BON1, QGP-1, and NCI-H727 in vitro. NET cells were treated with WNT974, PRI-724, or small interfering ribonucleic acids against β-catenin, and subsequent analyses included cell viability assays, flow cytometric cell cycle analysis, caspase3/7 assays and Western blot analysis. Results: Treatment of NET cells with WNT974 significantly reduced NET cell viability in a dose- and time-dependent manner by inducing NET cell cycle arrest at the G1 and G2/M phases without inducing apoptosis. WNT974 primarily blocked Wnt/β-catenin signaling by the dose- and time-dependent downregulation of low-density lipoprotein receptor-related protein 6 (LRP6) phosphorylation and non-phosphorylated β-catenin and total β-catenin, as well as the genes targeting the latter (c-Myc and cyclinD1). Furthermore, the WNT974-induced reduction of NET cell viability occurred through the inhibition of GSK-3-dependent or independent signaling (including pAKT/mTOR, pEGFR and pIGFR signaling). Similarly, treatment of NET cells with the β-catenin inhibitor PRI-724 caused significant growth inhibition, while the knockdown of β-catenin expression by siRNA reduced NET tumor cell viability of BON1 cells but not of NCI-H727 cells. Conclusions: The PORCN inhibitor WNT974 possesses antitumor properties in NET cell lines by inhibiting Wnt and related signaling. In addition, the β-catenin inhibitor PRI-724 possesses antitumor properties in NET cell lines. Future studies are needed to determine the role of Wnt/β-catenin signaling in NET as a potential therapeutic target.

Janus Kinase (JAK)-2 Does Not Play a Role in Bcr-Abl Signaling in Philadelphia Chromosome (Ph)-Positive (p190) Acute Lymphoblastic Leukemia (ALL) Cells.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4241-4241
Author(s):  
Stefan H. Faderl ◽  
Quin Van ◽  
Patricia E. Koch ◽  
David M. Harris ◽  
Inbal Hallevi ◽  
...  
Keyword(s):  
Cell Lines ◽  
Lymphoblastic Leukemia ◽  
Philadelphia Chromosome ◽  
Janus Kinase ◽  
Myelogenous Leukemia ◽  
Dependent Manner ◽  
Western Immunoblotting ◽  
Gm Csf ◽  
Dose Dependent

Abstract Novel immunochemotherapy regimens combined with imatinib mesylate (IA) have significantly improved treatment outcome of Ph+ ALL. Nevertheless, most adult patients with Ph+ ALL relapse and succumb to their disease. Recent reports suggested that Jak-2 is engaged in the signaling of Bcr-Abl in chronic myelogenous leukemia (CML) cells. Because Jak-2 inhibitory agents are currently investigated in clinical trials, we sought to explore the role of Jak-2 in the signaling of Bcr-Abl in Ph+ ALL assuming that inhibition of Jak-2 might be beneficial in the treatment of Ph+ ALL. To do this, we used our Ph+ (p190) ALL cell lines Z-119 and Z-181 (Estrov et al. J Cell Physiol166: 618, 1996). We chose these cells because in both lines Jak-2 can be activated. Both Z-119 and Z-181 cells express granulocyte-macrophage colony-stimulating factor (GM-CSF) receptors and GM-CSF activates Jak-2 and stimulates the proliferation of both cell lines. Using a clonogenic assay, we found that IA inhibited the proliferation of these cells at concentrations ranging from 50 to 500 nM. Because Bcr-Abl was found to activate the signal transducer and activator of transcription (STAT)-5 in CML cells, we used Western immunoblotting and found that IA inhibited the phosphorylation (p) of STAT5 in a dose-dependent manner in Ph+ ALL cells. To test whether JAk-2 plays a role in Bcr-Abl (p190) signaling we incubated Z-181 cells for 4 hours with or without 50, 100, 250, and 500 nM IA, extracted cellular protein and immunoprecipitated total STAT5 protein. Then, using Western immunoblotting we detected the Bcr-Abl p190 protein in all STAT5 immunoprecipitates and by using specific pSTAT5 antibodies, we demonstrated that IA induced a dose-dependent reduction in the levels of pSTAT5, but not of p190 protein, suggesting that the p190 Bcr-Abl kinase binds to and activates STAT5. Remarkably, neither Jak-2 nor pJak-2 was detected in either immunoprecipitate. To further delineate the role of Jak-2 in Bcr-Abl signaling we extracted protein from Z-181 cells and immunoprecipitated Jak-2. Neither Bcr-Abl nor STAT5 was detected in these immunoprecipitates, confirming that Jak-2 does not bind Bcr-Abl p190 protein and does not participate in the activation of STAT5. Taken together, our data suggest that Bcr-Abl (p190) binds and phosphorylates STAT5 whereas, Jak-2 is not engaged in Bcr-Abl (p190) signaling in Ph+ ALL cells.

The Receptor Tyrosine Kinase RON Is Constitutively Activated in Acute Myeloid Leukemia and May Represent a New Therapeutic Target.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 994-994
Author(s):  
Camille Fialin ◽  
Veronique De Mas ◽  
Stephane Manenti ◽  
Bernard Payrastre ◽  
Serge Roche ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Cell Lines ◽  
Receptor Tyrosine Kinase ◽  
Protein Level ◽  
Leukemic Cell ◽  
Down Regulation ◽  
Hematopoietic Stem ◽  
Inhibition Of Proliferation ◽  
Si Rna

Abstract Abstract 994 Poster Board I-16 Recepteur d'Origine Nantais (RON) is a receptor tyrosine kinase (RTK) expressed mostly on epithelial cells but also in normal hematopoietic stem cells and macrophages. RON is closely related to c-Met in terms of homology and function. Its oncogenic properties have been documented in solid tumors leading to the clinical development of small molecules inhibitors. However, the role of RON in haematological malignancies and specifically in AML, has received little attention. Interestingly, a truncated form of RON lacking most of the RON receptor extracellular domain but retaining the whole transmembrane and intracellular domains has been described in the leukemic cell line KG1 (Bardella C et al, Cancer Res 64, 5154–5161, 2004). Since RTK and TK play a crucial role in leukemogenesis, we have assessed the expression and the role of RON in both AML cell lines and patient samples. The expression of both full length (fl) and short form (sf) of RON was assessed in 71 AML samples by RT-PCR. fl-RON and sf-RON were found in 48/71 pts (68%) and 26/71 (37%) respectively, whereas both forms were undetectable in 17 samples (24%). RON expression was further confirmed at the protein level by western blot analysis in 20 samples. Conversely, c-Met was not expressed at the protein level in 10 cases tested. In leukemic cell lines, fl-RON and sf-RON were expressed both at the mRNA and protein levels in KG1 and KG1a but not in HL60 and U937. Immunoprecipitation analysis showed that fl-RON and sf-RON were constitutively phosphorylated on tyrosine in KG1/KG1a cells. This phosphorylation was fully inhibited by the dual c-Met/RON inhibitor, SU-11274. Cell signaling induced by RON has also been explored. Specific down regulation by si-RNA to RON induced a significant decrease of Lyn phosphorylation. Conversely, AKT phosphorylation was not influenced by RON down regulation. We then assessed the activity of SU-11274 on the proliferation and survival of KG1 (RON+) and HL60 (RON-). The proliferation of KG1 (IC50=3.5μM) but not HL60 (IC50 not reached at 10μM) was strongly inhibited in a time and dose dependant manner. This inhibition of proliferation was mostly due to apoptosis induction. Accordingly using clonogenic and cytotoxic assays, we show that only RON positive samples from AML patients responded to SU-11274 (n=8). Moreover, specific down regulation of RON by si-RNA inhibited the clonogenic properties of KG1 cells. Altogether, these data demonstrate that the tyrosine kinase RON is aberrantly deregulated in AML cells, control cell proliferation and could represent a new target for the treatment of AML. Disclosures: No relevant conflicts of interest to declare.

The Brd-Inhibitor OTX015 Is Active in Pre-Clinical Models of Mature B-Cell Lymphoid Tumors

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1657-1657 ◽  
Author(s):  
Paola Bonetti ◽  
Michela Boi ◽  
Maurilio Ponzoni ◽  
Maria Grazia Tibiletti ◽  
Anastasios Stahis ◽  
...  
Keyword(s):  
Cell Cycle ◽  
B Cell ◽  
Cell Lines ◽  
Proliferative Activity ◽  
Research Funding ◽  
Cell Lymphoma ◽  
Rt Pcr ◽  
Down Regulation ◽  
Myc Gene ◽  
Dose Dependent

Abstract Abstract 1657 Background: Bromodomain-containing proteins play an important role in gene expression regulation, via chromatin structure remodelling. Antitumor activity has been reported in acute and chronic hematological malignancies using inhibitors of BRD2/3/4, members of the Bromodomain and Extraterminal (BET) family. Here, we report anti-proliferative activity of OTX015, a novel selective orally bioavailable BRD2/3/4 inhibitor, in a large panel of cell lines derived from mature B-cell lymphoid tumors. Material and Methods: Established human cell lines derived from 13 diffuse large B-cell lymphoma (DLBCL), 4 mantle cell lymphoma (MCL), three splenic marginal zone lymphoma (SMZL) and from three multiple myeloma (MM) were treated with increasing doses of OTX015 (OncoEthix SA) and MTT assays were performed after 72 hours exposure. For cell cycle analysis, cells were treated and stained with Click-iT Edu Flow Cytometry Assay Kits (Invitrogen) and 7-AAD and analyzed for DNA content using a FACScan flow cytometer. Results were analyzed with FlowJo 7.6.3 software. RNA extracted using the Qiagen RNAEasy kit and reverse-transcribed using the Superscript First-Strand Synthesis System for RT-PCR kit according to the manufacturer's instructions. RT-PCR was performed using Fast SYBR Green Master Mix on a StepOnePlus Real-Time PCR System. For senescence detection, cells were stained using a b-Galactosidase Staining Kit (Calbiochem). Results: OTX015 demonstrated anti-proliferative activity in DLBCL cell lines (median IC50 0.192μM; range 0.069–12.68μM). Similar results were obtained on SMZL (median IC50 0.165μM, range 0.105–0.24μM), and on MM cell lines (median IC50 0.449μM; range 0.06–0.7μM). Conversely, MCL cell lines appeared less sensitive to OTX015 (median IC50 2.01μM; range 1.22- >15μM). Among DLBCL cell lines, there was no significant difference based upon the cell of origin of the cell lines. OTX105 caused a cell cycle arrest in G1 in a dose-dependent manner in 5/5 DLBCL and 3/3 MM cell lines, without an increase in cell death. An increase in the percentage of senescent cells after treatment with the BRD-inhibitor was observed in 1/1 sensitive DLBCL cell line. In order to understand the mechanism of action of OTX015, we assessed MYC mRNA levels before and after 24h treatment with increasing doses. We observed a dose-dependent suppression of MYC mRNA by OTX015 in 4/5 DLBCL and in 2/2 MM cell lines. In DLBCL, down-regulation of MYC mRNA was observed within 1h after treatment with OTX015, suggesting a direct effect of the compound on the MYC gene. To determine whether the suppression of MYC gene by OTX015 was reversible, DLBCL cell lines were treated for 2h with OTX015 and then the inhibitor was removed from the media. MYC mRNA suppression appeared reversible, as shown in DLBCL cell lines, which, after 2h exposure to OTX015, showed a time-dependent restoration of MYC mRNA expression to untreated levels after 2–3h. In one of the most sensitive DLBCL cell lines no MYC mRNA down-regulation was observed after treatment, suggesting that alternative pathways can be affected by BRD-inhibition. Conclusion: OTX015 is a new potent BRD-inhibitor with evident anti-proliferative activity in several cell lines representative of mature B-cell tumors. An apparently reversible down-regulation of MYC mRNA was commonly observed, appearing as a possible mechanism of action of the compound. The compound appears worth of further investigation as a new promising therapeutic agent in mature B-cell origin malignancies. A phase I trial is scheduled to start in 2012. Disclosures: Bonetti: OncoEthix SA: Research Funding. Inghirami:OncoEthix SA: Research Funding. Noel:OncoEthix SA: Membership on an entity's Board of Directors or advisory committees. Bertoni:OncoEthix SA: Research Funding.

Cyclin-Dependent Kinase 4/6 Inhibitor Abemaciclib Exerts Dose-Dependent Cytostatic and Cytocidal Effects on Multiple Myeloma Cells Via Autophagy

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 4478-4478 ◽  
Author(s):  
Noriyoshi Iriyama ◽  
Hirotsugu Hino ◽  
Shota Moriya ◽  
Masaki Hiramoto ◽  
Yoshihiro Hatta ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Growth ◽  
Cell Lines ◽  
Cell Apoptosis ◽  
Annexin V ◽  
Myeloma Cell ◽  
Parp Cleavage ◽  
Dependent Manner ◽  
Myeloma Cells ◽  
Dose Dependent

Abstract Background:Multiple myeloma (MM) is a hematologic malignancy characterized by the accumulation of abnormal plasma cells in the bone marrow. D-type cyclins (CCNDs), an important family of cell cycle regulators, are thought to be implicated in multiple myeloma (MM) development because CCNDs are commonly expressed in myeloma cells. CCND is known to positively regulate the cell cycle from G1 to S-phase initiation by binding to cyclin-dependent kinase (CDK) 4/6, resulting in potentiation of myeloma cell growth. These findings suggest a possible role for CDK4/6-targeting therapy in MM, yet the details remain incompletely understood. In this regard, we investigated the biological activity of abemaciclib, a potent, highly selective CDK4/6 inhibitor, in myeloma cell lines, to elucidate the mechanisms underlying the involvement of the CCND-CDK4/6 complex in cell cycle regulation and survival. Methods:The effects of abemaciclib on myeloma cells were investigated using three myeloma cell lines, KMS12-PE (CCND1-positive and CCND2-negative), RPMI8226 (CCND1-negative and CCND2-positive), and IM-9 (both CCND1- and CCND2-positive). Cell growth was assessed by trypan blue exclusion assay. Cell cycle analysis was performed using propidium iodide (PI) and apoptosis was measured using annexin V/PI staining via flow cytometry. Cell cycle regulated proteins, including p21 and p27, and phosphorylated proteins, including STAT1, STAT3, ERK, JNK, p38, and AKT, were evaluated using a phospho-flow method. Autophagy was assessed using CYTO-ID via flow cytometry. PARP cleavage was investigated via western blotting. Clarithromycin, an antibiotic agent belonging to the macrolide class, was used as an autophagy inhibitor. Results:Abemaciclib inhibited myeloma cell growth in a dose-dependent manner in all the cell lines evaluated, with significant differences seen at a concentration of 320 nM. Annexin V/PI staining revealed that 1 μM abemaciclib showed little or no effect on apoptosis, but 3.2 μM abemaciclib induced apparent myeloma cell apoptosis, with an increase in both the early and late apoptotic fractions. Therefore, 1 and 3.2 μM of abemaciclib were used in subsequent experiments for the assessment of cell growth and apoptosis, respectively. Cell cycle analyses revealed that 1 μM abemaciclib increased the fraction of cells in G0/G1 phase and decreased the fraction in S-G2/M phase. Furthermore, this effect was associated with the upregulation of p21 and p27 in the evaluated myeloma cells. PARP cleavage was observed in KMS12-PE cells treated with 3.2 μM abemaciclib, but not 1 μM, suggesting a close connection between the degree of PARP cleavage and apoptosis in myeloma cells. Importantly, abemaciclib induced autophagy in a dose-dependent manner. However, no apparent inhibitory effect on the autophagy-related phosphorylated proteins STAT1 (Y701), STAT3 (Y705), ERK (T202/Y204), JNK (T183/Y185), p38 (T180/Y182), or AKT (Y315) was observed in myeloma cells treated with 3.2 μM abemaciclib. To investigate the role of abemaciclib-induced autophagy on myeloma cell apoptosis, we further assessed the apoptotic effect of 3.2 μM abemaciclib or 50 μg/mL clarithromycin, alone or in combination. Clarithromycin did not induce apoptosis of myeloma cells. Importantly, clarithromycin treatment in combination with abemaciclib attenuated the apoptotic effect of abemaciclib. Discussion & Conclusions: Although the underlying mechanisms conferring the level of CCND expression are known to differ greatly (e.g., CCND translocation, hyperdiploidy, or activation of upstream pathways of CCND transcription), the results of the current study indicate that the CCND-CDK4/6 complex is closely involved in myeloma cell growth and survival regardless of the CCND family member present. In addition, we demonstrate that abemaciclib exerts multiple effects, such as myeloma cell apoptosis, via the PARP pathway or autophagy, as well as cell cycle regulation. Because abemaciclib in combination with clarithromycin inhibits myeloma cell apoptosis, the autophagy induced by abemaciclib is considered to have a critical role in the induction of apoptosis, so-called "autophagic cell death." These results provide novel insights into a possible therapeutic approach using abemaciclib to target CDK4/6 in patients with MM, and offer new possibilities for combination therapy with CDK4/6 inhibitors and autophagy regulators. Disclosures Iriyama: Novartis: Honoraria, Speakers Bureau; Bristol-Myers Squibb: Honoraria, Speakers Bureau. Hatta:Novartis Pharma: Honoraria.

scholarly journals Decorin induced by progesterone plays a crucial role in suppressing endometriosis

2014 ◽  
Vol 223 (2) ◽  
pp. 203-216 ◽  
Author(s):  
Yoshihiro Joshua Ono ◽  
Yoshito Terai ◽  
Akiko Tanabe ◽  
Atsushi Hayashi ◽  
Masami Hayashi ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Mrna Expression ◽  
Cell Lines ◽  
Stromal Cells ◽  
Crucial Role ◽  
Dependent Manner ◽  
Endometrial Stromal Cells ◽  
Endometrial Cells ◽  
Cycle Arrest ◽  
Dose Dependent

Dienogest, a synthetic progestin, has been shown to be effective against endometriosis, although it is still unclear as to how it affects the ectopic endometrial cells. Decorin has been shown to be a powerful endogenous tumor repressor acting in a paracrine fashion to limit tumor growth. Our objectives were to examine the direct effects of progesterone and dienogest on the in vitro proliferation of the human ectopic endometrial epithelial and stromal cell lines, and evaluate as to how decorin contributes to this effect. We also examined DCN mRNA expression in 50 endometriosis patients. The growth of both cell lines was inhibited in a dose-dependent manner by both decorin and dienogest. Using a chromatin immunoprecipitation assay, it was noted that progesterone and dienogest directly induced the binding of the decorin promoter in the EMOsis cc/TERT cells (immortalized human ovarian epithelial cells) and CRL-4003 cells (immortalized human endometrial stromal cells). Progesterone and dienogest also led to significant induced cell cycle arrest via decorin by promoting production of p21 in both cell lines in a dose-dependent manner. Decorin also suppressed the expression of MET in both cell lines. We confirmed that DCN mRNA expression in patients treated with dienogest was higher than that in the control group. In conclusion, decorin induced by dienogest appears to play a crucial role in suppressing endometriosis by exerting anti-proliferative effects and inducing cell cycle arrest via the production of p21 human ectopic endometrial cells and eutopic endometrial stromal cells.

Advanced Glycation End Products (AGEs)-Mediated Cell Growth of Human Acute Myelogenous Leukemia Via Mitogen-Activated Protein (MAP) Kinase Pathways.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2762-2762
Author(s):  
Ju Young Kim ◽  
Hyun Ki Park ◽  
Jin Sun Yoon ◽  
Eun Shil Kim ◽  
Kwang Sung Ahn ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Growth ◽  
Cell Lines ◽  
Cellular Proliferation ◽  
Myelogenous Leukemia ◽  
Dependent Manner ◽  
Glycation End Products ◽  
Mitogen Activated Protein ◽  
Acute Myelogenous ◽  
Dose Dependent

Abstract Advanced glycation end products (AGEs) are products of non-enzymatic glycation/oxidation of proteins/lipids that accumulate slowly during natural aging and at a much accelerated rate in a variety of disorders such as diabetes, renal failure, and Alzheimer’s disease. AGE modifications do not only change the physicochemical properties of the afflicted molecules, but also induce cellular signaling, activation of transcription factors and subsequent gene expression in vitro and in vivo. Most of the biologic activities associated with AGEs have been transduced by receptor for AGE (RAGE). Recently, AGEs are known to be in association with diverse cancers in terms of cellular proliferation and metastasis. However, little is known about the role of AGEs in acute myelogenous leukemia (AML). Here we examined the effects of the AGEs-RAGE interaction on the cell proliferation and intracellular signaling of AGEs in human leukemia cell lines. Expression of RAGE was observed in 8 AML cell lines examined, and up-regulated by treatment of AGE. AGE induced the proliferation of AML cell lines, HL60 and HEL, in a dose-dependent manner. Treatment with 5 μM of antisense S-ODN for RAGE did effectively inhibit cell growth of HEL cells. Exposure of HL60 and HEL with AGE induced a significant increase in the numbers of cells in S phase of cell cycle in a dose-dependent manner. AGE enhanced the expression of cell cycle regulatory proteins such as cyclin-dependent kinase (CDK) 2/4/6, cyclin D1/E/B in a dose- and a time-dependent manner. In addition, the protein levels of the cyclin-dependent kinase inhibitor (CDKI), p21 and p27, were decreased by 24 hr exposure of AGE from 10 to 200 μg/ml in HEL. Furthermore, treatment of HEL with 200 μg/ml of AGE triggered activation of mitogen-activated protein (MAP) kinases, Erk, Akt, and p38, pathways and in nuclear translocation of transcription factors NF-kB. These results indicated that AGE induced the cell growth of human AML cells, HL60 and HEL, via augmentation of cell cycle and activation of MAPK kinase pathways. Up-regulation of RAGE by exposure of AGE suggested that cellular proliferation of AML cells might be mediated in autocrine fashion.

Valproic Acid Inihibts Histone Deacetylases and Proliferation and Induces Cell Cycle Arrest and Apoptosis in Multiple Myeloma.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 5165-5165
Author(s):  
Martin Kaiser ◽  
Ulrike Heider ◽  
Ivana Zavrski ◽  
Jan Sterz ◽  
Kurt Possinger ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Multiple Myeloma ◽  
Valproic Acid ◽  
Cell Lines ◽  
Myeloma Cell ◽  
G1 Phase ◽  
Dependent Manner ◽  
Myeloma Cells ◽  
Cycle Arrest ◽  
Dose Dependent

Abstract Multiple myeloma remains an incurable disease in the majority of the patients and novel treatment strategies are urgently needed. A new class of drugs, the histone deacetylase (HDAC) inhibitors take influence in epigenetic modifications and have antiproliferative effects in some malignancies. Valproic acid (VPA) is an anticonvulsant drug and was recently shown to inhibit HDACs and suppress tumor growth. The drug is currently being evaluated in clinical studies in acute myeloid leukemia. Its effects on myeloma cells are unknown. The aim of this study was to evaluate the effects of VPA on proliferation, apoptosis and HDAC inhibition in multiple myeloma cell lines as well as in sorted human bone marrow multiple myeloma cells. Myeloma cell lines, OPM-2, NCI-H929, LP-1, and freshly isolated multiple myeloma cells from bone marrow aspirates were exposed to different concentrations of VPA for 4 to 72 hours. Cell proliferation, cell cycle distribution and apoptosis were assayed in reaction to the treatment. Proliferation decreased noticeably and apoptosis was induced in a dose-dependent manner in multiple myeloma cell lines as well as in freshly sorted primary myeloma cells. After 48 hours of incubation with VPA at 1 mM, approximately 46%, 52% and 25% of OPM-2, NCI-H929 and LP-1 cell lines had undergone specific apoptosis, respectively. Freshly sorted primary bone marrow myeloma cells from patients showed also specific apoptosis. In cell cycle analysis by flow cytometry, the population of cells in the G0/G1 phase increased, whereas cells in the S phase decreased in a time and dose dependent manner. Incubation of the cell line OPM-2, for example, with 1 mM VPA for 48 hours decreased the proportion of cells in the S phase from 39 % to 6 % of the total cell count and increased cells in the G0/G1 phase from 49 % to 85 %. Acetylation of histones and expression of cyclin D1 and the cell cycle regulators p21 and p27 were studied by western blot. Histone acetylation and p21 concentrations increased after VPA treatment whereas levels of p27 remained constant. A decrease in cyclin D1 concentrations was observed. Subapoptotic doses of VPA significantly decreased the production of VEGF in OPM-2 cell line. These data show that treatment with valproic acid effectively inhibits histone deacetylase activity, leading to the accumulation of acetylated histones in multiple myeloma cells. Parallel upregulation of cell cycle inhibitors like p21WAF1 was observed, together with a reduction of cyclin D1 levels. Myeloma cell proliferation was inhibited in a time and dose dependent manner and cell cycle arrest in the G0/G1 phase was induced by VPA treatment. VPA potently induced apoptosis in all human myeloma cell lines as well as in sorted primary multiple myeloma cells in a dose and time dependent manner. These results show for the first time that VPA acts as an HDAC inhibitor in multiple myeloma cells, induces G1 cell cycle arrest, potently inhibits tumor growth and markedly induces apoptosis. In addition to its direct antitumor effect, valproic acid may exert an antiangiogenic effect by reducing VEGF production in myeloma cells. These data provide the framework for clinical studies with valproic acid in multiple myeloma.

Sign in / Sign up

Export Citation Format

Share Document