The Small Molecule Pan-Bcl-2 Inhibitor GX15-070 Induces Apoptosis In Vitro in Mantle Cell Lymphoma (MCL) Cells and Exhibits a Synergistic Effect in Combination with the Proteasome Inhibitor Bortezomib.

Abstract Mantle cell lymphoma (MCL) is a lymphoid malignancy derived from a subset of mature B-cells with coexpression of CD5 and the chromosomal translocation t(11;14)(q13;q32). MCL patients present an aggressive clinical course and poor response to conventional chemotherapy due to either rapid relapse after an initial response or primary resistance to drugs. Thus, there is currently a strong effort to develop compounds that target novel biological pathways. In addition, MCL cells overexpress the antiapoptotic proteins Bcl-2, Bcl-XL and Mcl-1. The dysregulated Bcl-2 pathway represents an important target for a new-mechanism therapeutic approach. In this context, the pan-Bcl-2 inhibitor GX15-070 that belongs to a new family of compounds which mimic BH3-only proteins by binding to multiple antiapoptotic Bcl-2 members and consequently eliciting Bax and Bak dependent cytotoxicity. GX15-070 is currently being evaluated in Phase I clinical trials. GX15-070 induced apoptosis in vitro in primary cells from MCL patients as well in MCL cells lines, at doses ranging from 0,5μM to 5μM. GX15-070 induced phosphatidylserine exposure, mitochondrial depolarization, ROS generation, Bax and Bak conformational changes and caspase activation. As expected, pan-caspase inhibitors did not block apoptosis in accordance with the mitochondria-targeted nature of this new compound. The susceptibility of MCL cells correlates with the expression of Bcl-2, Mcl-1 and Bcl-XL, both at protein and mRNA levels. Although GX15-070 exhibited significant in vitro cytotoxicity in MCL as a single agent, we tested also this compound in combination with proteasome inhibitors. Bortezomib (PS-341, Velcade®) has shown promising results in MCL treatment. One of the drawbacks of proteasome inhibitors is the undesirable accumulation, due to absence of degradation, of antiapoptotic factors which could impede or slow apoptosis, such as Mcl-1 protein. With this rationale we evaluated a combination of bortezomib with the pan-Bcl-2 inhibitor GX15-070 in vitro in MCL cells. Preincubation of MCL cells with GX15-070 at doses ranging from 0,1μM to 1μM before bortezomib (1–10nM) addition induced a synergistic cytotoxic effect (Chou Talalay CI =[0,26–0,575]). In vitro, this new combination allows to reduce bortezomib dose 5 to 20 times, depending on the individuals. Western blot analysis revealed that this combination reduced Mcl-1 levels and displaced Bak from Mcl-1 sequestration. Moreover, upregulation of the proapoptotic BH3-only protein Noxa by bortezomib, was further increased when combined with GX15-070. All these findings suggest that GX15-070 and bortezomib combination could be a new therapeutic approach for MCL treatment.

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BET bromodomain inhibitor birabresib in mantle cell lymphoma: in vivo activity and identification of novel combinations to overcome adaptive resistance

ESMO Open ◽

10.1136/esmoopen-2018-000387 ◽

2018 ◽

Vol 3 (6) ◽

pp. e000387 ◽

Cited By ~ 10

Author(s):

Chiara Tarantelli ◽

Elena Bernasconi ◽

Eugenio Gaudio ◽

Luciano Cascione ◽

Valentina Restelli ◽

...

Keyword(s):

Mantle Cell Lymphoma ◽

Cell Lines ◽

Cell Lymphoma ◽

Antitumour Activity ◽

Single Agent ◽

Treatment Strategies ◽

Bet Inhibitor ◽

Mantle Cell

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.

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Inhibition of the Pan-Bcl-2 Family by the Small Molecule GX15-070 Induces Apoptosis in Mantle Cell Lymphoma (MCL) Cells and Enhances the Activity of Two Proteasome Inhibitors (NPI-0052 and Bortezomib), and Doxorubicin Chemotherapy.

Blood ◽

10.1182/blood.v108.11.2532.2532 ◽

2006 ◽

Vol 108 (11) ◽

pp. 2532-2532 ◽

Cited By ~ 1

Author(s):

Victor Y. Yazbeck ◽

Georgios V. Georgakis ◽

Yang Li ◽

David McConkey ◽

Michael Andreeff ◽

...

Keyword(s):

Mantle Cell Lymphoma ◽

Cell Lines ◽

Small Molecule ◽

Cell Lymphoma ◽

Proteasome Inhibitors ◽

Dependent Manner ◽

Intrinsic Apoptotic Pathway ◽

Phase I Clinical Trials ◽

Apoptotic Pathway ◽

Mantle Cell

Abstract Mantle cell lymphoma (MCL) accounts for 6–8% of all non-Hodgkin lymphomas (NHLs). It is an aggressive lymphoma with a poor prognosis--it is generally considered incurable with conventional treatments, and median survival is 3–4 years with a 10-year survival of only 10–15%. There is no accepted standard of care and effective treatments are greatly needed. Bcl-2 family proteins are important regulators of the intrinsic apoptotic pathway and are involved in oncogenesis and chemoresistance of a variety of tumor types, including lymphoma. Antiapoptotic proteins of the Bcl-2 family are overexpressed in mantle cell lymphoma (MCL) cells and may be responsible, in part, for drug resistance. GX15-070 is a small-molecule antagonist of the BH3-binding groove of the Bcl-2 family of proteins, and is currently in Phase I clinical trials. Consequently, we determined the activity of GX15-070 in 3 MCL cell lines (Jeko-1, Mino, and SP53). Cell viability was determined by MTS assay, apoptosis by Annexin-V binding and FACS analysis, and molecular changes by western blot. GX15-070 induced apoptosis in all three MCL cell lines in a dose and time-dependent manner. In the SP53 cell line, GX15-070 decreased MCL-1 and Bak levels, increased Bax and cleaved caspase 3. Furthermore, GX15-070 activated both the extrinsic and intrinsic apoptotic pathway as evident by cleavage of caspase 8, 9, and Bid. Both bortezomib and the novel proteasome inhibitor NPI-0052 induced single agent antiproliferative activity in MCL. GX15-070 enhanced the effect of both proteasome inhibitors. Additionally, GX15-070 showed an additive effect with doxorubicin. These studies suggest that GX15-070 may have a therapeutic value in MCL either alone or in combination with proteasome inhibitors or chemotherapy.

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Mantle cell lymphoma activation enhances bortezomib sensitivity

Blood ◽

10.1182/blood-2010-02-268375 ◽

2010 ◽

Vol 116 (20) ◽

pp. 4185-4191 ◽

Cited By ~ 23

Author(s):

Sarah K. Brennan ◽

Brooke Meade ◽

Qiuju Wang ◽

Akil A. Merchant ◽

Jeanne Kowalski ◽

...

Keyword(s):

Stem Cells ◽

Mantle Cell Lymphoma ◽

Cell Lymphoma ◽

Proteasome Inhibitors ◽

Tumor Formation ◽

Intracellular Enzyme ◽

Wide Range ◽

Mantle Cell

AbstractPatients with mantle cell lymphoma (MCL) typically respond to initial treatment but subsequently relapse. This pattern suggests that a population of MCL cells is both drug resistant and capable of clonogenic growth. The intracellular enzyme retinaldehyde dehydrogenase (ALDH) provides resistance to several toxic agents. ALDH can also identify stem cells in normal adult tissues and tumorigenic cancer stem cells in several human malignancies. We studied ALDH expression in MCL and found small populations of ALDH+ cells that were highly clonogenic. Moreover, ALDH+ MCL cells were relatively quiescent and resistant to a wide range of agents. Normal B cells can be activated by specific unmethylated cytosine-phosphate-guanosine (CpG) DNA motifs through toll-like receptor 9, and we found that the synthetic CpG oligonucleotide 2006 (CpG) reduced the frequency of quiescent ALDH+ MCL cells, induced terminal plasma cell differentiation, and limited tumor formation in vitro and in vivo. Treatment with CpG also significantly enhanced the activity of the proteasome inhibitor bortezomib that was associated with induction of the unfolded protein response. Our data suggest that CpG may target clonogenic and resistant ALDH+ cells as well as improve the activity of proteasome inhibitors in MCL.

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Sonic Hedgehog Signaling in Mantle Cell Lymphoma.

Blood ◽

10.1182/blood.v108.11.2046.2046 ◽

2006 ◽

Vol 108 (11) ◽

pp. 2046-2046 ◽

Cited By ~ 1

Author(s):

Ganapati V. Hegde ◽

Katy Emanuel ◽

Avadhut D. Joshi ◽

Corey M. Munger ◽

Dennis D. Weisenburger ◽

...

Keyword(s):

B Cell ◽

Cyclin D1 ◽

Mantle Cell Lymphoma ◽

Sonic Hedgehog ◽

Therapeutic Approach ◽

Cell Lymphoma ◽

B Cell Malignancies ◽

Shh Signaling ◽

Mantle Cell

Abstract Mantle cell lymphoma (MCL) is associated with poor clinical outcome among all the B-cell malignancies. MCL cells have a characteristic phenotype including IgM+, IgD+, CD5+, CD10−, CD19+, CD20+, Bcl2+, CD23−, CD24+, and have a (11:14) (q13:q32) translocation, involving the Bcl-1 locus and the IgH heavy chain joining region, resulting in up-regulation of Bcl-1/PRAD-1 with increased Cyclin D1 expression. In spite of our understanding of B cell development, we do not have effective therapeutic approach to treat MCL. This warrants an immediate understanding of the biology MCL cells, and key signaling pathways underlying the disease progression. Further, these key signaling pathways involved in MCL could be specifically targeted, which may have potential therapeutic value. Emerging evidences have revealed that sonic hedgehog (Shh) signaling promotes tumor cell proliferation, and protects them from apoptosis in different cancers such as pancreatic cancer, prostate cancer, gastric cancer, medulloblastoma, basal cell carcinoma, breast cancer, etc. In addition, targeting the Shh signaling has been shown as a potential therapeutic approach to treat some of these cancers. However, the role of Shh signaling has not been reported in any of B cell malignancies including MCL. Therefore, we studied the status of Shh signaling molecules in the proliferation and survival of MCL cells in vitro using JVM-2, Granta-519, Jeko-1 and Z138 cell lines and human primary MCL cells. Our results demonstrate that the molecules involved in the Shh signaling like patched and smoothened receptors, and the target transcription factors, GLI were over expressed in Granta-519, Jeko-1, Z-138 and JVM-2 MCL cell lines, and patients primary MCL cells compared to normal human B lymphocytes. Addition of exogenous Shh increased the proliferation of JVM-2 cells in vitro. There was an increased transcripts level of GLI1, BCL2 and Cyclin D1 (CCND1) in JVM-2 cells following the addition of Shh. Addition of Shh-signaling inhibitor Cyclopamine abrogated the increased proliferation and transcription of the above genes induced by Shh in JVM-2 cells (figure 1). Furthermore, the Gli2 anti-sense oligonucleotide decreased CCND1 and BCL2 transcript expression, as well as decreased the proliferation of JVM2 cells in vitro (figure 2). Taken together, these results suggest that Shh-Gli signaling may be one of the pathways that regulate the Bcl-2 and Cyclin D1 activation and thereby regulate the proliferation and apoptosis of MCL cells. Therefore, further dissecting of the Shh-Gli mediated regulation of Bcl2 signaling may have potential implications in advancing the treatment for MCL. Figure 1: Figure 1:. Figure 2: Figure 2:.

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P276-00, a cyclin-dependent kinase inhibitor, modulates cell cycle and induces apoptosis in vitro and in vivo in mantle cell lymphoma cell lines

Molecular Cancer ◽

10.1186/1476-4598-11-77 ◽

2012 ◽

Vol 11 (1) ◽

pp. 77 ◽

Cited By ~ 14

Author(s):

Nitesh P Shirsath ◽

Sonal M Manohar ◽

Kalpana S Joshi

Keyword(s):

Cell Cycle ◽

Mantle Cell Lymphoma ◽

Kinase Inhibitor ◽

Cell Lymphoma ◽

Cyclin Dependent Kinase ◽

Cyclin Dependent Kinase Inhibitor ◽

Mantle Cell Lymphoma Cell ◽

Mantle Cell

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Autophagic degradation of NOXA underlies stromal cell-mediated resistance to proteasome inhibitors in mantle cell lymphoma

Leukemia Research ◽

10.1016/j.leukres.2021.106672 ◽

2021 ◽

pp. 106672

Author(s):

Yoshiaki Kuroda ◽

Daisuke Koyama ◽

Jiro Kikuchi ◽

Shigehisa Mori ◽

Tatsuo Ichinohe ◽

...

Keyword(s):

Mantle Cell Lymphoma ◽

Stromal Cell ◽

Cell Lymphoma ◽

Proteasome Inhibitors ◽

Mantle Cell ◽

Autophagic Degradation

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Therapeutic Activity of Lenalidomide in Mantle Cell Lymphoma and Indolent Non-Hodgkin’s Lymphomas

Advances in Hematology ◽

10.1155/2012/523842 ◽

2012 ◽

Vol 2012 ◽

pp. 1-7 ◽

Cited By ~ 4

Author(s):

Marco Gunnellini ◽

Lorenzo Falchi

Keyword(s):

Mantle Cell Lymphoma ◽

Cell Lymphoma ◽

Single Agent ◽

Response Rates ◽

Prognostic Scores ◽

Cell Transplant ◽

Survival Times ◽

Phase Ii Studies ◽

Mantle Cell ◽

Hodgkin's Lymphomas

Mantle cell lymphoma (MCL) comprises 3–10% of NHL, with survival times ranging from 3 and 5 years. Indolent lymphomas represent approximately 30% of all NHLs with patient survival largely dependent on validated prognostic scores. High response rates are typically achieved in these patients with current first-line chemoimmunotherapy. However, most patients will eventually relapse and become chemorefractory with poor outcome. Alternative chemoimmunotherapy regimens are often used as salvage strategy and stem cell transplant remains an option for selected patients. However, novel approaches are urgently needed for patients no longer responding to conventional chemotherapy. Lenalidomide is an immunomodulatory drug with activity in multiple myeloma, myelodisplastic syndrome and chronic lymphoproliferative disorders. In phase II studies of indolent NHL and MCL lenalidomide has shown activity with encouraging response rates, both as a single agent and in combination with other drugs. Some of these responses may be durable. Optimal dose of lenalidomide has not been defined yet. The role of lenalidomide in the therapeutic armamentarium of patients with indolent NHL or MCL will be discussed in the present paper.

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