The BH3 Mimetic, ABT-737, Is Effective Against Bcl-2 Overexpressing Lymphoid Tumors.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 826-826 ◽  
Author(s):  
Kylie D. Mason ◽  
Cassandra J. Vandenberg ◽  
Mark F. van Delft ◽  
Andrew H. Wei ◽  
Suzanne Cory ◽  
...  

Abstract Lymphoid tumors often respond poorly to conventional cytotoxics, a common cause being their impaired sensitivity to apoptosis, such as that caused by Bcl-2 overexpression. A strategy to overcoming this is to use mimics of the natural antagonists of pro-survival Bcl-2, the BH3 only proteins. A promising BH3 mimetic is ABT-737, which targets Bcl-2 and closely related pro-survival proteins. We evaluated its potential utility by testing it on cell lines, clinical samples and on a relevant mouse lymphoma model. We assessed the sensitivity of B cell lymphoma cell lines and primary CLL samples to ABT-737, either alone or in combination. To ascertain its efficacy in vivo, we utilized a mouse model based on the Eμ-myc tumor that is readily transplantable and amenable to genetic manipulation. When syngeneic recipient mice were inoculated with tumors, they develop widespread lymphoma, fatal unless treated by agents such as cyclophosphamide. We found that ABT-737, on its own, was cytotoxic only to a subset of cell lines and primary CLL samples. However, it can synergize potently with agents such as dexamethasone, suggesting that this agent might be useful in combination with currently used chemotherapeutics. In the Eμ myc mouse lymphoma model, treatment with ABT-737 alone did not control the disease as multiple independently derived tumors proved refractory to treatment with this agent. However, ABT-737 was partially effective as a single agent for treating bitransgenic tumors derived from crosses of the Eμmyc and Eμ-bcl-2 transgenic mice. ABT-737 therapy prolonged the survival of recipient mice transplanted with tumors from 30 to 60 days. When combined with a low dose of cyclophosphamide (50mg/kg), long term stable remissions were achieved, which were sustained even longer than control mice treated with much higher doses of cyclophosphamide (300mg/kg). We found that ABT-737 was well tolerated as a single agent and when combined with low doses of cytotoxics such as cyclophosphamide. Thus, ABT-737 may prove to be efficacious for those tumors highly dependent on Bcl-2 for their survival. We found that despite its high affinity for Bcl-2, Bcl-xL and Bcl-w, many cell types proved refractory to ABT-737 as a single agent. We show that this resistance reflects its inability to target another pro-survival relative Mcl-1. Down-regulation of Mcl-1 by several strategies conferred sensitivity to ABT-737. Furthermore, enforced Mcl-1 expression in the Eμmyc/bcl-2 bitransgenic mouse lymphoma model conferred marked resistance as mice transplanted with such tumors died as rapidly as the untreated counterparts. However, enhanced Bcl-2 overexpression on these tumors had little impact on the in vivo response, suggesting that ABT-737 can be utilized even when Bcl-2 is markedly overexpressed. ABT-737 appears to be a promising agent for the clinic. It potently sensitizes certain lymphoid tumors to conventional cytotxics in vitro. The synergy observed between dexamethasone and ABT-737 on some lymphoid lines in culture suggests that it is attractive for clinical testing. Encouragingly, ABT-737 appeared efficacious in vivo against Bcl-2 overexpressing tumors when combined with a reduced dose of cyclophosphamide, suggesting that it will be useful for treating even those Bcl-2-overexpressing tumors that are normally highly chemoresistant.

ESMO Open ◽  
2018 ◽  
Vol 3 (6) ◽  
pp. e000387 ◽  
Author(s):  
Chiara Tarantelli ◽  
Elena Bernasconi ◽  
Eugenio Gaudio ◽  
Luciano Cascione ◽  
Valentina Restelli ◽  
...  

BackgroundThe outcome of patients affected by mantle cell lymphoma (MCL) has improved in recent years, but there is still a need for novel treatment strategies for these patients. Human cancers, including MCL, present recurrent alterations in genes that encode transcription machinery proteins and of proteins involved in regulating chromatin structure, providing the rationale to pharmacologically target epigenetic proteins. The Bromodomain and Extra Terminal domain (BET) family proteins act as transcriptional regulators of key signalling pathways including those sustaining cell viability. Birabresib (MK-8628/OTX015) has shown antitumour activity in different preclinical models and has been the first BET inhibitor to successfully undergo early clinical trials.Materials and methodsThe activity of birabresib as a single agent and in combination, as well as its mechanism of action was studied in MCL cell lines.ResultsBirabresib showed in vitro and in vivo activities, which appeared mediated via downregulation of MYC targets, cell cycle and NFKB pathway genes and were independent of direct downregulation of CCND1. Additionally, the combination of birabresib with other targeted agents (especially pomalidomide, or inhibitors of BTK, mTOR and ATR) was beneficial in MCL cell lines.ConclusionOur data provide the rationale to evaluate birabresib in patients affected by MCL.


Author(s):  
Ye Xie ◽  
Jia Yao ◽  
Weilin Jin ◽  
Longfei Ren ◽  
Xun Li

Limited by the poor proliferation and restricted sources of adult hepatocytes, there is an urgent need to find substitutes for proliferation and cultivation of mature hepatocytes in vitro for use in disease treatment, drug approval, and toxicity testing. Hepatocyte-like cells (HLCs), which originate from undifferentiated stem cells or modified adult cells, are considered good candidates because of their advantages in terms of cell source and in vitro expansion ability. However, the majority of induced HLCs are in an immature state, and their degree of differentiation is heterogeneous, diminishing their usability in basic research and limiting their clinical application. Therefore, various methods have been developed to promote the maturation of HLCs, including chemical approaches, alteration of cell culture systems, and genetic manipulation, to meet the needs of in vivo transplantation and in vitro model establishment. This review proposes different cell types for the induction of HLCs, and provide a comprehensive overview of various techniques to promote the generation and maturation of HLCs in vitro.


Cells ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1592
Author(s):  
Surendra R. Punganuru ◽  
Viswanath Arutla ◽  
Wei Zhao ◽  
Mehrdad Rajaei ◽  
Hemantkumar Deokar ◽  
...  

There is a desperate need for novel and efficacious chemotherapeutic strategies for human brain cancers. There are abundant molecular alterations along the p53 and MDM2 pathways in human glioma, which play critical roles in drug resistance. The present study was designed to evaluate the in vitro and in vivo antitumor activity of a novel brain-penetrating small molecule MDM2 degrader, termed SP-141. In a panel of nine human glioblastoma and medulloblastoma cell lines, SP-141, as a single agent, potently killed the brain tumor-derived cell lines with IC50 values ranging from 35.8 to 688.8 nM. Treatment with SP-141 resulted in diminished MDM2 and increased p53 and p21cip1 levels, G2/M cell cycle arrest, and marked apoptosis. In intracranial xenograft models of U87MG glioblastoma (wt p53) and DAOY medulloblastoma (mutant p53) expressing luciferase, treatment with SP-141 caused a significant 4- to 9-fold decrease in tumor growth in the absence of discernible toxicity. Further, combination treatment with a low dose of SP-141 (IC20) and temozolomide, a standard anti-glioma drug, led to synergistic cell killing (1.3- to 31-fold) in glioma cell lines, suggesting a novel means for overcoming temozolomide resistance. Considering that SP-141 can be taken up by the brain without the need for any special delivery, our results suggest that SP-141 should be further explored for the treatment of tumors of the central nervous system, regardless of the p53 status of the tumor.


2019 ◽  
Vol 21 (Supplement_3) ◽  
pp. iii4-iii4
Author(s):  
A Bruning-Richardson ◽  
H Sanganee ◽  
S Barry ◽  
D Tams ◽  
T Brend ◽  
...  

Abstract BACKGROUND Targeting kinases as regulators of cellular processes that drive cancer progression is a promising approach to improve patient outcome in GBM management. The glycogen synthase kinase 3 (GSK-3) plays a role in cancer progression and is known for its pro-proliferative activity in gliomas. The anti-proliferative and cytotoxic effects of the GSK-3 inhibitor AZD2858 were assessed in relevant in vitro and in vivo glioma models to confirm GSK-3 as a suitable target for improved single agent or combination treatments. MATERIAL AND METHODS The immortalised cell line U251 and the patient derived cell lines GBM1 and GBM4 were used in in vitro studies including MTT, clonogenic survival, live cell imaging, immunofluorescence microscopy and flow cytometry to assess the cytotoxic and anti-proliferative effects of AZD2858. Observed anti-proliferative effects were investigated by microarray technology for the identification of target genes with known roles in cell proliferation. Clinical relevance of targeting GSK-3 with the inhibitor either for single agent or combination treatment strategies was determined by subcutaneous and orthotopic in vivo modelling. Whole mount mass spectroscopy was used to confirm drug penetration in orthotopic tumour models. RESULTS AZD2858 was cytotoxic at low micromolar concentrations and at sub-micromolar concentrations (0.01 - 1.0 μM) induced mitotic defects in all cell lines examined. Prolonged mitosis, centrosome disruption/duplication and cytokinetic failure leading to cell death featured prominently among the cell lines concomitant with an observed S-phase arrest. No cytotoxic or anti-proliferative effect was observed in normal human astrocytes. Analysis of the RNA microarray screen of AZD2858 treated glioma cells revealed the dysregulation of mitosis-associated genes including ASPM and PRC1, encoding proteins with known roles in cytokinesis. The anti-proliferative and cytotoxic effect of AZD2858 was also confirmed in both subcutaneous and orthotopic in vivo models. In addition, combination treatment with AZD2858 enhanced clinically relevant radiation doses leading to reduced tumour volume and improved survival in orthotopic in vivo models. CONCLUSION GSK-3 inhibition with the small molecule inhibitor AZD2858 led to cell death in glioma stem cells preventing normal centrosome function and promoting mitotic failure. Normal human astrocytes were not affected by treatment with the inhibitor at submicromolar concentrations. Drug penetration was observed alongside an enhanced effect of clinical radiotherapy doses in vivo. The reported aberrant centrosomal duplication may be a direct consequence of failed cytokinesis suggesting a role of GSK-3 in regulation of mitosis in glioma. GSK-3 is a promising target for combination treatment with radiation in GBM management and plays a role in mitosis-associated events in glioma biology.


2019 ◽  
Vol 116 (34) ◽  
pp. 16981-16986 ◽  
Author(s):  
Claudio Scuoppo ◽  
Jiguang Wang ◽  
Mirjana Persaud ◽  
Sandeep K. Mittan ◽  
Katia Basso ◽  
...  

To repurpose compounds for diffuse large B cell lymphoma (DLBCL), we screened a library of drugs and other targeted compounds approved by the US Food and Drug Administration on 9 cell lines and validated the results on a panel of 32 genetically characterized DLBCL cell lines. Dasatinib, a multikinase inhibitor, was effective against 50% of DLBCL cell lines, as well as against in vivo xenografts. Dasatinib was more broadly active than the Bruton kinase inhibitor ibrutinib and overcame ibrutinib resistance. Tumors exhibiting dasatinib resistance were commonly characterized by activation of the PI3K pathway and loss of PTEN expression as a specific biomarker. PI3K suppression by mTORC2 inhibition synergized with dasatinib and abolished resistance in vitro and in vivo. These results provide a proof of concept for the repurposing approach in DLBCL, and point to dasatinib as an attractive strategy for further clinical development in lymphomas.


2003 ◽  
Vol 77 (3) ◽  
pp. 2134-2146 ◽  
Author(s):  
Vicky M.-H. Sung ◽  
Shigetaka Shimodaira ◽  
Alison L. Doughty ◽  
Gaston R. Picchio ◽  
Huong Can ◽  
...  

ABSTRACT Hepatitis C virus (HCV) is a major cause of chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. Studies of HCV replication and pathogenesis have so far been hampered by the lack of an efficient tissue culture system for propagating HCV in vitro. Although HCV is primarily a hepatotropic virus, an increasing body of evidence suggests that HCV also replicates in extrahepatic tissues in natural infection. In this study, we established a B-cell line (SB) from an HCV-infected non-Hodgkin's B-cell lymphoma. HCV RNA and proteins were detectable by RNase protection assay and immunoblotting. The cell line continuously produces infectious HCV virions in culture. The virus particles produced from the culture had a buoyant density of 1.13 to 1.15 g/ml in sucrose and could infect primary human hepatocytes, peripheral blood mononuclear cells (PBMCs), and an established B-cell line (Raji cells) in vitro. The virus from SB cells belongs to genotype 2b. Single-stranded conformational polymorphism and sequence analysis of the viral RNA quasispecies indicated that the virus present in SB cells most likely originated from the patient's spleen and had an HCV RNA quasispecies pattern distinct from that in the serum. The virus production from the infected primary hepatocytes showed cyclic variations. In addition, we have succeeded in establishing several Epstein-Barr virus-immortalized B-cell lines from PBMCs of HCV-positive patients. Two of these cell lines are positive for HCV RNA as detected by reverse transcriptase PCR and for the nonstructural protein NS3 by immunofluorescence staining. These observations unequivocally establish that HCV infects B cells in vivo and in vitro. HCV-infected cell lines show significantly enhanced apoptosis. These B-cell lines provide a reproducible cell culture system for studying the complete replication cycle and biology of HCV infections.


Haematologica ◽  
2020 ◽  
Vol 105 (11) ◽  
pp. 2584-2591 ◽  
Author(s):  
Eugenio Gaudio ◽  
Chiara Tarantelli ◽  
Filippo Spriano ◽  
Francesca Guidetti ◽  
Giulio Sartori ◽  
...  

Antibody drug conjugates represent an important class of anti-cancer drugs in both solid tumors and hematological cancers. Here, we report preclinical data on the anti-tumor activity of the first-in-class antibody drug conjugate MEN1309/OBT076 targeting CD205. The study included preclinical in vitro activity screening on a large panel of cell lines, both as single agent and in combination and validation experiments on in vivo models. CD205 was first shown frequently expressed in lymphomas, leukemias and multiple myeloma by immunohistochemistry on tissue microarrays. Anti-tumor activity of MEN1309/OBT076 as single agent was then shown across 42 B-cell lymphoma cell lines with a median IC50 of 200 pM and induction of apoptosis in 25/42 (59.5%) of the cases. The activity appeared highly correlated with its target expression. After in vivo validation as the single agent, the antibody drug conjugate synergized with the BCL2 inhibitor venetoclax, and the anti-CD20 monoclonal antibody rituximab. The first-in-class antibody drug targeting CD205, MEN1309/OBT076, demonstrated strong pre-clinical anti-tumor activity in lymphoma, warranting further investigations as a single agent and in combination.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 286-286 ◽  
Author(s):  
Constantine S. Mitsiades ◽  
Cecile Rouleau ◽  
Krishna Menon ◽  
Beverly Teicher ◽  
Massimo Iacobelli ◽  
...  

Abstract Introduction: Defibrotide (DF) is a polydisperse oligonucleotide with anti-thrombotic, thrombolytic, anti-ischemic, and anti-adhesive properties, which selectively targets the microvasculature and has minimal hemorrhagic risk. DF is an effective treatment for veno-occlusive disease (VOD), an important regimen-related toxicity in stem cell transplantation characterized by endothelial cell injury. DF also augments stem cell mobilization by modulating adhesion in vivo. Because of its cytoprotective effect on the endothelium, we specifically investigated whether DF protects tumor cells from cytotoxic anti-tumor agents. Further, because of its broad anti-adhesive properties, we evaluated whether DF modulates the interaction of MM cells with bone marrow stromal cells (BMSCs), which confers growth, survival and drug resistance in the BM milieu. Methods: In vitro studies in isogenic dexamethasone (Dex)-sensitive and resistant MM cell lines (MM-1S and MM1R, respectively) showed that DF does not attenuate the sensitivity of MM cells to Dex, the proteasome inhibitor bortezomib (PS-341), melphalan (MEL), vinca alkaloids (vincristine, vinblastine), taxanes (paclitaxel) or platinum (cisplatin), but does decrease their sensitivity to doxorubicin. These selective effects in vitro of DF in protecting tumor cells against doxorubicin and modestly sensitizing MM cells to platinum was also confirmed in solid tumor breast (MCF-7) and colon (HT-29) carcinoma cell lines. Although DF had minimal in vitro inhibitory effect on MM or solid tumor cell growth in vitro, it showed in vivo activity as a single agent and enhanced the responsiveness of MM tumors to cytotoxic chemotherapeutics, such as MEL or cyclophosphamide, in human MM xenografts in SCID/NOD mice. The in vivo single-agent activity and chemosensitizing properties of DF, coupled with its lack of major in vitro activity, suggested that DF may not directly target tumor cells, but rather modulate tumor cell interaction with BMSCs. In an ex vivo model of co-culture of primary MM tumor cells with BMSCs (which protects MM cells against conventional chemotherapy), DF alone had a only modest effect on tumor cell viability, but it significantly enhanced MM cell sensitivity to cytotoxic chemotherapy (e.g. MEL), suggesting that a major component of the biological effects of DF may be attributable not to direct targeting of tumor cells, but to modulation of the interactions that tumor cells develop with the local stromal milieu. Conclusion: Our studies show that DF mediates in vivo anti-MM activity by abrogating interactions of MM cells with their BM milieu, thereby enhancing sensitivity and overcoming resistance to conventional chemotherapy. These data support future clinical trials of DF, in combination with both conventional and novel therapies, to improve patient outcome in MM.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 528-528 ◽  
Author(s):  
Mohammad Luqman ◽  
Ssucheng J. Hsu ◽  
Matthew Ericson ◽  
Sha Klabunde ◽  
Seema Kantak

Abstract HCD122 (formerly known as CHIR-12.12), is a fully human anti-CD40 monoclonal antibody (mAb) currently in Phase I clinical trials for treatment of chronic lymphocytic leukemia (CLL) and multiple myeloma (MM). An IgG1 antibody selected for its potency as an antagonist of the CD40 signaling pathway, HCD122 both inhibits CD40/CD40L-stimulated growth of lymphoma cells ex vivo, and mediates highly effective Antibody Dependent Cell-mediated Cytotoxicity (ADCC) in vitro. As a single agent, HCD122 exhibits potent anti-tumor activity in vivo, in preclinical models of MM, Hodgkin’s lymphoma, Burkitt’s lymphoma, mantle cell lymphoma and diffused large B-cell lymphoma (DLBCL). Although several therapeutic antibodies approved for treatment of Non-Hodgkin’s Lymphoma have clinical activity as single agents, combining these antibodies with standard-of-care chemotherapeutic regimens such as CHOP (cytoxan, vincristine, doxorubicin and prednisone) is proving optimal for both increasing response rates and extending survival, and antibodies currently in clinical development are likely to be used in combination therapies in the future. Therefore the studies reported here examine the effects of combining HCD122 with CHOP, the standard for treatment of high grade NHL, in in vitro and in vivo models of DLBCL. In the xenograft RL model of DLBCL, HCD122 administered intraperitoneally weekly at 1 mg/kg as a single agent, or in combination with CHOP (H-CHOP), and CHOP alone all significantly reduced tumor growth at day 25 when compared to treatment with huIgG1 control antibody (P<0.001). However, tumor growth delay (time to reach tumor size of 500 mm3) was significantly longer for H-CHOP (17.5 days), than for CHOP (8 days) or HCD122 (6 days) (p < 0.001). No toxicity was observed with the H-CHOP combination. Interestingly, at the end of the study (day 35), reduction in tumor growth was significantly greater in the treatment group that received H-CHOP than the groups that received either 10 mg/kg Rituxan plus CHOP (R-CHOP) (p < 0.05) or CHOP alone (p < 0.001). These data show that in this model, treatment with the combination H-CHOP results in greater anti-tumor efficacy than with either modality alone or R-CHOP. We have observed that in vitro, exposure to CD40 Ligand (CD40L) results in aggregation of DLBCL cells, and postulate that interfering with the ability of cancer cells to adhere and interact with each other and their microenvironment may potentiate the effect of chemotherapeutics. To elucidate the mechanism by which the combination of HCD122 and CHOP enhanced efficacy in vivo, we developed an in vitro system to examine the effects of HCD122 on the expression of adhesion molecules in the RL and SU-DHL-4 cell lines. In these studies, HCD122 inhibited CD40L-induced expression of CD54, CD86 and CD95 in both cell lines, as well as aggregation of SU-DHL-4 cells. The combined effect of each of the components of CHOP with HCD122 in three-dimensional spheroid cultures is currently under investigation. These data provide a therapeutic rationale for combination of HCD122 with CHOP in DLBCL clinical trials.


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