2-Chlorodeoxyadenosine (2-CDA) and Dexamethasone Induce Apoptosis in Multiple Myeloma (MM) Via Different Mechanisms.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4792-4792
Author(s):  
Bolin Liu ◽  
Zeying Fang ◽  
Jian Ma ◽  
Thomas E. Dillon ◽  
Tim E. Byers ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Growth Inhibition ◽  
Cell Lines ◽  
B Lymphocyte ◽  
Therapeutic Potential ◽  
Growth Control ◽  
Cross Resistance ◽  
Dependent Manner ◽  
Caspase 9 ◽  
Ic50 Values

Abstract Although 2-CDA has been active on B-lymphocyte derived malignancies, its potential for myeloma growth control has not been fully investigated. In the present study on a pair of MM cell lines, dexamethasone-sensitive (MM1.S) and dexamethasone-resistant (MM1.R), we sought to determine whether 2-CDA can effectively induce apoptosis and growth inhibition in both cell lines and whether there is cross resistance between 2-CDA and dexamethasone in MM1.R cells. Cell proliferation assay (MTS) releaved that 2-CDA significantly inhibited both MM1.S and MM1.R cell growth in a dose dependent manner, with the minimum (10%) and maximum (100%) inhibition concentration of 12.5 nM/L and 500 nM/L for the MM1.S, and 25 nM/L and 500 nM/L for the MM1.R cells, respectively. The IC50 values of 2-CDA in the MM1.S and MM1.R cells were 48 nM/L and 60 nM/L, respectively. No cross resistance was observed between 2-CDA and dexamethasone in the MM1.R cells. On the molecular level, dexamethasone induced PARP and caspase-9 cleavage, and increased the level of p27kip1 only in the MM1.S cells. 2-CDA treatment in both cell lines resulted in DNA fragmentation as well as strong PARP and caspase-9 cleavage, but no significant changes in the levels of P-Akt, P-MARK, p27kip1, E2F1, and cyclin D1, indicating that 2-CDA induces growth inhibition and cell death in MM cell lines likely through mitochondria-dependent apoptotic mechanism. Cell cycle analyses by flow cytometry showed that dexamethasone (5μM/L) treatment increased sub-G1 (apoptosis) cells to 8.1% only in the MM1.S cells, while the majority (87%) of cells were arrested in the G1 phase of cell cycle in 24 hours. In contrast, 2-CDA (0.5μM/L for 24 hours) strongly induced apoptosis in both cell lines (sub-G1 population increased to 19.6% and 22.1% for the MM1.S and MM1.R cells, respectively) without changing their cell cycle profiles. These data suggest that dexamethasone and 2-CDA induce apoptosis in myeloma cells via different mechanisms, which would provide a theoretical basis for combination therapy for MM with these two agents. Furthermore, our results also show that 2-CDA alone is capable of inducing apoptosis in the MM1.R cells, suggesting that 2-CDA may have therapeutic potential for MM patients with a dexamethasone-resistant phenotype.

PI3K a Selective Inhibitor Induces Growth Inhibition In Mantle Cell Lymphoma

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1812-1812
Author(s):  
Yixin Zhou ◽  
Linhua Jin ◽  
Stefania Pittaluga ◽  
Mark Raffeld ◽  
Takashi Miida ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Growth Inhibition ◽  
Cyclin D1 ◽  
Cell Cycle Arrest ◽  
Cell Lines ◽  
Pi3k Inhibitor ◽  
Dependent Manner ◽  
Pi3k Inhibitor Ly294002 ◽  
Pi3k Inhibitors ◽  
Cycle Arrest

Abstract Abstract 1812 Deregulation of the phosphatidylinositol 3-kinase (PI3K)-mediated signaling plays an important role in the development of cell proliferation of mantle cell lymphoma (MCL). The PI3K pathway activation in MCL has been shown to result from constitutive B cell receptor (BCR) activation which is directly mediated by the Class IA PI3K p110 isoforms (a, β, and d). However, their relative contribution in MCL is not fully understood. In this study, the activity and molecular mechanisms of isoform-selective PI3K inhibitors which target different isoforms of the p110-kDa subunit has been investigated. We utilized the isoform-selective PI3K inhibitors; PI3-Ka inhibitor IV (p110a), TGX115 (p110b), IC87114 (p110d) and the non-specific PI3K inhibitor LY294002 (all inhibitors were purchased commercially). The p110a and p110d but not p110b isoform protein expression was detected in all tested MCL cell lines (Granta 519, JVM-2, Z138, Jeko-1, MINO). PI3-Ka inhibitor IV as well as non-specific PI3K inhibitor LY294002 induced cell growth inhibition with dose-dependent manner (IC50 at 48 hrs; PI3-Ka inhibitor IV: 17.5 μM for Granta 519, 14.3 μM for Jeko-1, 16.5 μM for Z138, LY294002: 14.8 μM for Granta 519, 19.4 μM for Jeko-1, 15.0 μM for Z138, MTT test). However, neither IC87114 nor TGX115 showed significant cell growth inhibition up to 40mM. Low dose of PI3-Ka inhibitor IV (5 μM) or LY294002 (5 μM) induced G0/G1 cell cycle arrest (increase of G0/G1 phase: PI3-Ka inhibitor IV 17.9 % for Granta 519, 28.2 % for Jeko-1, LY294002 19.3 % for Granta 519, 14.5 % for Jeko-1), and the higher dose (10 μM) increased apoptosis(specific apoptosis: PI3-Ka inhibitor IV 10.8 % for Granta 519, 15.3 % for Jeko-1, LY294002 13.6 % for Granta 519, 19.6 % for Jeko-1). No induction of cell cycle arrest/apoptosis by IC87114 or TGX115 treatment was observed. We then tried to assess the inhibition of PI3K/Akt signaling activation by p110a and p110d inhibitors. PI3-Ka inhibitor IV (10 μM) completely diminished phosphorylated (p-) Akt in all cell lines analyzed. Further investigation with 1–10 μM PI3-Ka inhibitor IV or IC87114 in Granta 519 and Jeko-1 cells declared that 1 μM PI3-Ka inhibitor IV almost diminished p-Akt and p-S6rp in both cells. The phosphorylation level of other PI3K/Akt signaling downstream substrates, GSK3-b and 4E-BP1, were down-regulated in dose dependent manner. Recently, GSK3-b kinase has been shown to negatively regulate cell cycle progression through Cyclin D1 repression in MCL. We observed that PI3-Ka inhibitor IV decreased Cyclin D1 expression and active pRb which are responsible for G0/G1 cell cycle arrest. The treatment with IC87114 (10 μM) performed moderate decrease of p-Akt, p-S6rp, and p-4E-BP, while no change in the levels of p-GSK3-b, Cyclin D1, or p-pRb was observed in both Granta 519 and Jeko-1 cells. We also tested whether the combination of PI3-Ka inhibitor IV or IC87114 with the proteasome inhibitor bortezomib induces synergistic cytotoxicity in MCL. No synergistic anti-proliferative effect was observed in any of the MCL cell lines analyzed. These findings demonstrate that p110a may be the responsible Class IA PI3K isoform for the development of MCL cell proliferation, and p110a isoform-selective PI3K inhibitor but not p110d or p110b inhibitors may provide a better therapeutic index relative to pan-PI3K inhibitors. Disclosures: No relevant conflicts of interest to declare.

Arsenic trioxide–induced apoptosis in myeloma cells: p53-dependent G1 or G2/M cell cycle arrest, activation of caspase-8 or caspase-9, and synergy with APO2/TRAIL

Blood ◽  
2003 ◽  
Vol 101 (10) ◽  
pp. 4078-4087 ◽  
Author(s):  
Qun Liu ◽  
Susan Hilsenbeck ◽  
Yair Gazitt
Keyword(s):  
Cell Cycle ◽  
Arsenic Trioxide ◽  
Cell Lines ◽  
Myeloma Cell ◽  
Caspase 8 ◽  
Dependent Manner ◽  
Caspase 9 ◽  
Myeloma Cells ◽  
Induced Apoptosis ◽  
In Cells

Abstract Arsenic trioxide (ATO) has been shown to induce differentiation and apoptosis in acute promyelocytic leukemia (APL) cells concomitant with down-regulation of the PML-RARα fusion protein, a product of the t(15:17) translocation characteristic of APL leukemic cells. However, ATO is also a potent inducer of apoptosis in a number of other cancer cells lacking the t(15:17) translocation. The exact mechanism of ATO-induced apoptosis in these cells is not yet clear. We tested the effect of ATO on 7 myeloma cell lines with varying p53 status and report that in cells with mutated p53, ATO induced rapid and extensive (more than 90%) apoptosis in a time- and dose-dependent manner concomitant with arrest of cells in G2/M phase of the cell cycle. Myeloma cells with wild-type (wt) p53 were relatively resistant to ATO with maximal apoptosis of about 40% concomitant with partial arrest of cells in G1 and up-regulation of p21. The use of caspase blocking peptides, fluorescence-tagged caspase-specific substrate peptides, and Western immunoblotting confirmed the involvement of primarily caspase-8 and -3 in ATO-induced apoptosis in myeloma cells with mutated p53 and primarily caspase-9 and -3 in cells expressing wt p53. We also observed up-regulation by ATO of R1 and R2 APO2/TRAIL (tumor necrosis factor–related apoptosis-inducing ligand) receptors. Most important, however, we observed a synergy between ATO and APO2/TRAIL in the induction of apoptosis in the partially resistant myeloma cell lines and in myeloma cells freshly isolated from myeloma patients. Our results justify the use of the combination of these 2 drugs in clinical setting in myeloma patients.

scholarly journals Oxymatrine Induces Apoptosis in Human Myeloma Cells By Cell Cycle Arrest and Activation of Caspase-Dependent Apoptosis

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 5727-5727
Author(s):  
Wenjun Wu ◽  
Cai Wu ◽  
Fuming Zi ◽  
Yi Li ◽  
Li Yang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Flow Cytometry ◽  
Growth Inhibition ◽  
Signaling Pathway ◽  
Cell Lines ◽  
Western Blotting ◽  
Cell Apoptosis ◽  
Conflicts Of Interest ◽  
Dependent Manner ◽  
Rt Pcr

Abstract Background : Multiple myeloma (MM) is a B cell malignant hematologic cancer. Despite the introduction of new drugs and improvement of chemotherapy, MM is still an incurable disease. Oxymatrine (OMT), the active ingredients of traditional Chinese herbal medicine sophora, has been reported to have antitumor activity. This study was to estimate the therapeutic efficacy of OMT in MM. Methods: The growth inhibition of myeloma cell lines (RPMI8226, U266, ARP-1) or primary cells by OMT was assessed by MTT assay. Apoptosis of MM cells was examined by annexin V-FITC using flow cytometry analysis. DNA content was analyzed by flow cytometry. RT-PCR and western-blot analysis were used to assess the expression of Bcl-2 family proteins and the IAP family proteins. Western blotting was also used to elucidate the signaling pathway that may mediate OMT-induced apoptosis of MM cells. Results: OMT treatment resulted in cell growth inhibition and apoptosis in primary MM cells and all tested MM cell lines in a dose-dependent manner (P <0.05). To elucidate OMT -induced MM cell apoptosis, MM cell lines were treated with or without OMT for 24h and assessed for caspase activation and signaling pathway by Western blotting. The results showed the cleavage of PARP, caspase-3, and caspase-9, and p-AKT were down-regulated after OMT treatment. The mRNA expression of survivin and HIAP by RT-PCR was down-regulated. OMT treatment at 5mM for 48h resulted in increased G-phase cells and decreased S-phase cells in MM cell lines (P <0.05). Cell cycle repressor P21 protein was up-regulated while CDK4, CDK6 and CyclinD1 expression was down-regulated. Our finding also showed a synergistic anti-MM activity of OMT and dexamethasone or adriamycin at a low does (CI<1). In addition, LC3-II expression was significantly increased both in RPMI8226 and U266 cells after treatment with OMT. However, treatment with different doses of OMT and 5 mM autophagy inhibitor 3-MA, significant increased cell apoptosis (P <0.05). Conclusion: Our findings demonstrate the anti-MM activity of OMT and indicate that OMT alone or together with other MM chemotherapeutics may be a prospective treatment for MM. Disclosures No relevant conflicts of interest to declare.

Effects of the multikinase inhibitor regorafenib in neuroblastoma.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 10553-10553
Author(s):  
Peter E. Zage ◽  
Divya Subramonian ◽  
Qianxing Mo ◽  
Shixia Huang
Keyword(s):  
Cell Cycle ◽  
Retinoic Acid ◽  
Cell Viability ◽  
Signaling Pathways ◽  
Cell Lines ◽  
Intracellular Signaling ◽  
Therapeutic Potential ◽  
Neuroblastoma Cells ◽  
Dependent Manner ◽  
Western Blots

10553 Background: Neuroblastoma (NB) is the most common extracranial solid pediatric tumor, and children with high-risk NB have poor survival rates and need novel treatment strategies. Regorafenib, a multi-receptor tyrosine kinase (RTK) inhibitor approved for treating adult solid tumors such as advanced metastatic colorectal cancer and gastrointestinal stromal tumors, inhibits many RTKs, including PDGFR-β, VEGFR1-3, RET, c-Kit and FGFR family members. Based on the potential roles for these targets in neuroblastoma pathogenesis, we explored the therapeutic potential of Regorafenib alone and in combination with 13-cis-retinoic acid against neuroblastoma cells. Methods: We treated NB cell lines with increasing concentrations of Regorafenib and measured cell viability using MTT assays. We further measured the occupied percent confluence over time using continuous live cell imaging. We performed Western blots for caspase cleavage to measure apoptosis and flow cytometry to determine cell cycle expression. We performed Reverse Phase Protein Array (RPPA) analysis of neuroblastoma cells before and after treatment with regorafenib combined with 13- cis-retinoic acid. Results: IC50values for the tested cell lines ranged between 2.5mcM and 12.5mcM after 72 hours of exposure to Regorafenib, and decreased viability was due to a combination of apoptosis and cell cycle arrest. RPPA analysis identified alterations in multiple proteins and pathways after Regorafenib with retinoic acid treatment, including the PI3K/Akt/mTOR and Jak/Stat pathways. Phosphorylation of Erk1/2, S6, Akt, and c-Jun were decreased, while protein expression of GATA3 was increased in a dose-dependent manner. Conclusions: Regorafenib treatment results in reduced neuroblastoma cell viability and increased apoptosis via effects on several signaling pathways. Effects on intracellular signaling pathways associated with responses to the combination of regorafenib plus retinoic acid represent opportunities to develop novel combination therapies, representing potential new therapeutic strategies for children with neuroblastoma.

Effect of berubicin, the 4'-o-benzylated doxorubicin analog, on growth inhibition and apoptosis in multiple myeloma.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e18557-e18557 ◽  
Author(s):  
Michael Wang ◽  
Luhong Sun ◽  
Izabela Fokt ◽  
Liang Zhang ◽  
Arumugam Jayakumar ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Clinical Trial ◽  
Multiple Myeloma ◽  
Growth Inhibition ◽  
Cell Lines ◽  
Bone Marrow Cells ◽  
Cancer Center ◽  
Dependent Manner ◽  
M Cell ◽  
Dose Dependent

e18557 Background: Doxorubicin (DOX), an anthracycline, topoisomerase II inhibitor, is routinely used for hematologic malignancies including multiple myeloma (MM); however, its efficacy is limited by drug resistance and cardiotoxcity. To overcome these limitations, we designed, synthesized and tested Berubicin (BRN). BRN has been evaluated in clinical trials in neuroblastoma multiforme. It is a representative of a novel class of mechanistically altered anthracycline analogs. The data obtained from this study will serve as the basis for the rapid translation of BRN from the bench to the clinic in a phase I clinical trial for patients with MM at MD Anderson Cancer Center. Methods: We investigated the effects of BRN, DOX and Bortezomib (BTZ) in 3 human MM cell lines, MM1S, ARP-1, U266, and freshly isolated primary samples from patients with MM. MM cells were treated with BRN, DOX, and BTZ. The effects of these compounds on cell proliferation, apoptosis, and the cell cycle were analyzed using MTS assay and flow cytometry analysis. Results: BRN potently inhibited the growth of the established MM cell lines, as well as the freshly isolated primary MM cells in a dose-dependent manner. It showed growth inhibition at IC50 of 5.99 nM (U266), 5.21 nM (MM1S) and 3.99 nM (ARP-1), and was more potent than doxorubicin (IC50 14.63 nM, 7.24 nM and 11.06 nM) and bortezomib (IC50 304.9 nM, 15.47 nM and 53.19 nM). In contrast, BRN did not affect the proliferation of patient-derived normal bone marrow cells (CD138- cells) at the concentrations that were lethal to MM cells. Conclusions: Berubicin not only induced apoptosis in 3 cell lines in dose-dependent manners but also induced G2/M cell cycle arrest in 3 cell lines. In conclusion, BRN was effective against MM cells in vitro and will be applied to our planned clinical trial.

scholarly journals Resveratrol Induces Cell Cycle Arrest and Apoptosis in Malignant NK Cells Via JAK2/STAT3 Pathway Inhibition

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1343-1343 ◽  
Author(s):  
Ly Quoc Trung ◽  
Luis Jorge Espinoza ◽  
Akiyoshi Takami ◽  
Akiyo Yoshida ◽  
Shinji Nakao
Keyword(s):  
Cell Cycle ◽  
Nk Cells ◽  
Cell Cycle Arrest ◽  
Cell Lines ◽  
Intracellular Signaling ◽  
Nk Cell ◽  
Therapeutic Potential ◽  
Dependent Manner ◽  
Stat3 Pathway ◽  
Cycle Arrest

Abstract Abstract 1343 Natural killer (NK)-cell malignancies, particularly aggressive NK-cell leukemias/lymphomas, have poor prognoses. Although recent regimens that include L-asparaginase substantially improve outcomes, novel therapeutic approaches are needed to improve clinical responses. Recent reports have shown that the signal transducer and activator of transcription 3 (STAT3) pathway is critical for proliferation and survival of malignant NK cells. Resveratrol is a naturally-occurring polyphenol that has been extensively studied for its anti-inflammatory, cardioprotective, and anti-cancer activities. In this study, we investigated the potential anti-tumor activities of resveratrol against the NK cell lines KHYG-1, NKL, NK-92, and NK-YS. Resveratrol significantly suppressed cell proliferation in a dose- and time-dependent manner in these four cell lines. Flow cytometry analysis with annexin V/propidium iodide staining showed a variable but consistent induction of apoptosis in the four cell lines treated with resveratrol for 48 hours, ranging from 57.1±6.9% of apoptosis in the L-asparaginase resistant cell line KHYG-1 to 53.4±9.7%, 28.8±3.3%, and 51.7±6.7% in NKL, NK-92, and NK-YS cells respectively (Fig. 1a). Notably, the anti-tumor activity of resveratrol against NK cell lines was p53 independent as demonstrated by equal efficacy of resveratrol against NK cell lines pretreated with the p53 inhibitor Pifithrin-α. Immunoblot analysis to study intracellular signaling in resveratrol-treated cells showed suppression of constitutively active STAT3 in all four cell lines 24 hours after treatment. Remarkably, resveratrol inhibited JAK2 phosphorylation, but had no effect on other known upstream mediators of STAT3 activation such as PTEN and Tyk2 (Fig. 1b). Resveratrol induced robust G1 cell cycle arrest and down-regulation of two anti-apoptotic proteins, Mcl-1 and survivin, both of which are downstream effectors of the STAT-3 pathway. Furthermore, resveratrol enhanced the pro-apoptotic and anti-proliferative activities of L-asparaginase against NKL and NK-92 cells by 32% and 126% respectively. These data indicate that resveratrol possesses a potent anti-tumor effect via inactivation of the STAT3 pathway in malignant NK cells. These mechanistic findings suggest that resveratrol may have therapeutic potential against NK cell malignancies. Our finding that resveratrol is a bonafide JAK2 inhibitor extends its therapeutic potential to other diseases with deregulated JAK2 signaling. Disclosures: No relevant conflicts of interest to declare.

Induction of Growth Inhibition and Apoptosis by TZD18, a Novel Dual Ligand for PPAR alpha/gamma, in Human Ph-Positive ALL Cells In Vitro.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2088-2088
Author(s):  
Elena Elstner ◽  
Hongyu Liu ◽  
Chuanbing Zang ◽  
Dachuan Liu ◽  
Shunnan Xu ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Growth Inhibition ◽  
Cell Cycle Arrest ◽  
Cell Lines ◽  
Hormone Receptors ◽  
Therapeutic Agent ◽  
Dependent Manner ◽  
Cyclin Dependent Kinase ◽  
Apoptosis Induction ◽  
Cycle Arrest

Abstract Peroxisome proliferator-activated receptors (PPARs) are ligand activated nuclear hormone receptors which play key roles in the differentiation and lipid metabolism of adipocytes. Recent data frequently indicated that PPAR ligands are also implicated in the growth inhibition, differentiation and apoptosis induction of several human cancers with diverse tissues. We previously showed that Pioglitazone (PGZ), a specific PPARgamma ligand and a member of the approved thiazolidinedione (TZD) class of anti-diabetic drugs, inhibited growth and induced apoptosis of human ALL cell lines including Ph-positive ALL cells (Zang et. al., Leukemia Research, 28:387, 2004). In this study, effects of a novel dual ligand specific for PPARalpha/gamma, TZD18 (MERCK, NJ, USA), on Ph-positive ALL cell lines, BV173, SD1 and Sup-B15 were examined. We noted that treatment of these cells with TZD18 resulted in growth inhibition in a dose-dependent manner which was associated with a G1 to S cell cycle arrest. This growth inhibition was much stronger than that of PGZ. However, this effect seemed not to be meditated through activation of PPARalpha or PPARgamma, since antagonists of PPARalpha or gamma could not reverse it. By studying the key regulators of cell cycle progression, we found that the expression of the cyclin dependent kinase inhibitor (CDKI) p27kip1, but not that of p21cip1, was enhanced whereas the expression of c-myc, cyclin D2, and cyclin dependent kinase 2 and 4 (CDK2 and CDK4) was decreased when these cells were treated with TZD18. Therefore, upregulation of p27kip1 and downregulation of cyclin Ds and CDKs may account for the G1 cell cycle arrest. Furthermore, a remarkable apoptosis induction was found in Ph-positive ALL cells treated with this dual ligand as measured by cell-death ELISA. No obvious alteration of bcl-2 levels but an upregulation of bax were observed in apoptotic cells. An activation of caspase-8 and caspase-9 by this ligand was also noticed. Of clinical importance, TZD18 enhanced the cytotoxic effect of Imatinib, a specific therapeutic agent for Ph-positive ALL. Overall, our findings strongly suggest that TZD18 may offer a new therapeutic agent for treatment of Ph-positive ALL in an adjuvant setting. (This study was supported by grants from Deutsche Jose Carreras Leukaemie-Stiftung and Deutsche Forschungsgemeinschaft to EE)

The Plk-1 Inhibitor BI 2536 Counteracts the Growth of Neoplastic Mast Cells and Synergizes with the KIT D816V-Targeting Drug Midostaurin (PKC412) in Producing Growth-Inhibition.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3554-3554
Author(s):  
Veronika Ferenc ◽  
Karoline V. Gleixner ◽  
Alexander Gruze ◽  
Michael Kneidinger ◽  
Christian Baumgartner ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Mast Cells ◽  
Growth Inhibition ◽  
Leukemia Cell ◽  
Leukemia Cell Line ◽  
Thymidine Uptake ◽  
Dependent Manner ◽  
Ic50 Values ◽  
Bi 2536 ◽  
Kit D816v

Abstract Systemic mastocytosis (SM) is a myeloid neoplasm characterized by abnormal growth and accumulation of mast cells (MC) in various internal organs. In most patients, the D816V-mutated variant of c-KIT, which mediates resistance against several tyrosine kinase (TK) inhibitors like imatinib, is found. In advanced SM, the response of neoplastic MC to conventional drugs is poor and the prognosis is grave. Therefore current research is attempting to identify novel targets in neoplastic MC. Polo-like kinase 1 (Plk-1) is a serine/threonine kinase that plays an essential role in mitosis and has recently been introduced as a new target in myeloid leukemias. In the present study, we analyzed expression and function of Plk-1 in neoplastic human MC, and asked whether Plk-1 can serve as a target of therapy in SM. As determined by immunohistochemistry, primary neoplastic MC were found to display activated/phosphorylated Plk-1 in all patients examined (n=5). The human MC leukemia cell line HMC-1 was also found to exhibit activated Plk-1. In addition, we found that primary neoplastic MC as well as HMC-1 cells express Plk-1 mRNA in RT-PCR experiments. As assessed by 3H-thymidine-uptake experiments, the Plk-1-targeting drug BI 2536 (Boehringer Ingelheim GmbH, Germany) was found to inhibit the proliferation of HMC-1 cells in a dose-dependent manner (IC50 5–15 nM). The effect of BI 2536 was seen in both subclones of HMC-1, i.e. in HMC-1.1 cells displaying KIT G560V (but not KIT D816V), and HMC-1.2 cells exhibiting both KIT G560V and KIT D816V, with comparable IC50 values. Moreover, BI 2536 was found to inhibit the proliferation of primary neoplastic cells, with IC50 values ranging between 5 and 50 nM. The growth-inhibitory effects of BI 2536 on HMC-1 cells were found to be associated with mitotic arrest and G2-M cell cycle arrest as well as consecutive apoptosis. In normal bone marrow or peripheral blood mononuclear cells, neither mitotic cell arrest nor apoptosis were observed after treatment with BI 2536. In a consecutive phase of the study, we asked whether combined targeting of KIT D816V and Plk-1 would lead to synergistic drug-interactions. For this purpose, HMC-1 cells and primary neoplastic MC were coincubated with BI 2536 and midostaurin (PKC412), a multitargeted kinase inhibitor that blocks KIT D816V TK activity. In these experiments, BI 2536 was found to synergize with midostaurin in counteracting the proliferation of HMC-1 cells and primary neoplastic MC. In conclusion, our data show that activated Plk-1 is detectable in MC neoplasms and plays a role in cell cycle progression and viability of neoplastic MC. Targeting of Plk-1 with BI 2536 leads to growth inhibition and apoptosis in neoplastic MC. Furthermore, BI 2536 synergizes with midostaurin in counteracting growth of neoplastic MC. Targeting of Plk-1 may be an attractive new pharmacologic concept in advanced SM.

Effect of new anti-neoplastic agent, MK615, from Japanese apricot, ume, on growth of breast cancer cells in vitro

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 11105-11105
Author(s):  
A. Nakagawa ◽  
T. Sawada ◽  
T. Okada ◽  
T. Ohsawa ◽  
M. Adachi ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Cycle ◽  
Growth Inhibition ◽  
Cancer Cells ◽  
Cell Lines ◽  
Breast Cancer Cells ◽  
Breast Cancer Cell Lines ◽  
Dependent Manner ◽  
Japanese Apricot

11105 Background: MK615 is an extract mixture from Japanese apricot, UME. In this study, the anti-neoplastic effects of MK615 against breast cancer cells were investigated. Methods: Two breast cancer cell lines, MDA-MB-468 (MDA) and MCF7, were cultured with (600, 300, 150 μg/ml) or without MK615. After 72 hours of incubation, growth inhibition was evaluated by MTT assay, and the mechanism of the anti-neoplastic effect of MK615 was evaluated by cell cycle- and apoptosis assay. Results: MK615 inhibited the growth of MDA and MCF7 in a dose-dependent manner. The percentage growth inhibition of MDA at dosages of 600, 300, and 150 μg/ml was 59.2%, 52.4%, and 23.3%, respectively, and that for MCF7 was 83.5%, 52.7%, and 16.6%, respectively. Cell cycle analysis showed that MK615 increased the proportion of cells in G2-M phase in both MDA (7.8% to 11.7%) and MCF7 (8.1% to 18.7%), and finally both cell lines became apoptotic. The proportion of apoptotic cells increased with incubation time. Conclusions: MK615 effectively inhibits the growth of breast cancer cells in vitro, possibly by cell cycle modification and apoptosis induction. No significant financial relationships to disclose.

scholarly journals The CDK4/6 Inhibitor Palbociclib Exerts Growth-Inhibitory Effects on Neoplastic Mast Cells and Synergizes with Midostaurin in Producing Growth Arrest

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1363-1363 ◽  
Author(s):  
Mathias A. Schneeweiss ◽  
Gabriele Stefanzl ◽  
Daniela Berger ◽  
Gregor Eisenwort ◽  
Mohamad Jawhar ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Mast Cells ◽  
Growth Inhibition ◽  
Cell Lines ◽  
Cell Cycle Progression ◽  
Drug Effects ◽  
Cycle Progression ◽  
Kit Mutation ◽  
Ic50 Values ◽  
Kit D816v

Abstract Aggressive systemic mastocytosis (ASM) and mast cell leukemia (MCL) are rare, malignant diseases with an unfavorable prognosis. In a majority of patients, the transforming KIT mutation D816V is detectable. Currently, several drugs are available for the treatment of ASM/MCL, including midostaurin, a KIT D816V-targeting drug that has recently been approved for the treatment of advanced SM in the US and in Europe. However, when applied as single drug, midostaurin usually fails to induce durable remissions in patients with ASM/MCL, and the same holds true for all other drugs tested in the ASM/MCL context so far. Therefore, drug combinations, including established drugs and novel targeted drugs are currently being examined for their anti-neoplastic effects in ASM/MCL. CDK4 and CDK6 are kinases that play an essential role in cell cycle-initiation in normal and neoplastic cells. However, the role of CDK4/6 as potential therapeutic targets in neoplastic mast cells (MC) has not been analyzed so far. Recently, three CDK4/6 inhibitors, palbociclib, ribociclib and abemaciclib, have been translated into clinical application. The aim of the current study was to evaluate the effects of these CDK4/6 inhibitors on cell cycle progression, proliferation and survival of neoplastic MC. In initial experiments, we employed the MCL-related cell lines HMC-1.1 (lacking KIT D816V), HMC-1.2 (KIT D816V+), ROSAKIT WT, ROSAKIT D816V and MCPV-1 (expressing RAS G12V, Large T and hTert). In 3H-thymidine incorporation experiments, all three CDK4/6-inhibitors were found to block proliferation in both HMC-1 sub-clones and both ROSA sub-clones, with comparable IC50 values (<0.5 µM). In MCPV-1 cells, similar results were obtained, but higher concentrations of palbociclib, ribociclib and abemaciclib were required to block proliferation (IC50 1-5 µM). These data suggest that CDK4/6-inhibitors exert anti-proliferative effects in neoplastic MC independent of the presence of KIT D816V. In a next step, we examined drug effects on primary bone marrow cells obtained from patients with KIT D816V+ indolent SM (n=3), ASM (n=1), SM with an associated hematologic neoplasm, ASM-AHN (n=5) and MCL (n=2). As determined by 3H-thymidine uptake, palbociclib was found to inhibit cell proliferation at pharmacologically meaningful concentrations in all donors tested, with IC50 values ranging between 5 nM and 250 nM. Similar effects were obtained when applying ribociclib (25-500 nM) and abemaciclib (5-500 nM). To learn more about the mechanisms underlying the effects of the CDK4/6 inhibitors on neoplastic MC, cell cycle progression and apoptosis were examined in HMC-1.1 and HMC-1.2 cells after drug exposure. In both cell lines, the palbociclib-induced growth inhibition was found to be accompanied by cell cycle arrest in the G1-phase. Moreover, all three CDK4/6 inhibitors were found to produce time- and dose-dependent apoptosis in HMC-1.1 and HMC-1.2 cells during 72 hours of incubation. In a next step, Western blot experiments were performed using antibodies against the main downstream target of CDK6, retinoblastoma protein-1 (Rb-1). The Rb-1 antigen was found to be expressed in phosphorylated form (p-Rb-1) in HMC-1.1 and HMC-1.2 cells. As expected, all 3 CDK4/6 inhibitors were found to suppress p-Rb-1 expression in both HMC-1 cell lines, suggesting specific drug effects. In a final step, we examined potential cooperative drug effects using palbociclib and the KIT D816V-targeting drug midostaurin. In these experiments, palbociclib was found to synergize with midostaurin in inducing growth inhibition in HMC-1 cells. In conclusion our data suggest that inhibition of CDK4/6 may be a new promising approach for the treatment of patients with advanced SM. In addition, our data suggest that CDK4/6 inhibitors may represent promising combination partners for midostaurin in the treatment of ASM/MCL. Whether treatment with CDK4/6 inhibitors alone or in combination with KIT inhibition, is indeed sufficient to control proliferation of neoplastic MC in vivo in patients with advanced SM remains to be determined in forthcoming studies. Disclosures Hoermann: Novartis: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria; Pfizer: Honoraria. Sperr:Novartis: Honoraria; Pfizer: Honoraria; Daiichi Sankyo: Honoraria. Reiter:Incyte: Consultancy, Honoraria. Valent:Incyte: Honoraria; Pfizer: Honoraria; Novartis: Honoraria.

Sign in / Sign up

Export Citation Format

Share Document