Search bioRxiv⌕ Search

Biology subjects

Cascione, L.

Publications and source records attributed to Cascione, L..

4 recordsLinked to original sources

The ATR inhibitor elimusertib exhibits anti-lymphoma activity and synergizes with the PI3K inhibitor copanlisib

PurposeThe DNA damage response (DDR) is the cellular process devoted to the preservation of an intact genome. The DDR is often deregulated in lymphoma cells due to high levels of DNA damage, tumor suppressor inactivation, increased replication stress observed after oncogene activation, or high amounts of reactive oxygen species. The ataxia telangiectasia and Rad3-related (ATR) kinase is a crucial factor of DDR in the response to DNA single strand breaks. ATR inhibitors are a class of agents that have shown considerable clinical potential in this context. Experimental DesignWe characterized the activity of the ATR inhibitor elimusertib (BAY 1895344) in a panel of lymphoma cell lines. Furthermore, we evaluated the activity of elimusertib in combination with the clinically approved PI3K inhibitor copanlisib in in vitro and in vivo lymphoma models. ResultsElimusertib exhibited in vitro activity across a variety of lymphoma subtypes which was associated with expression of genes related to replication stress. Elimusertib also demonstrated wide-spread anti-tumor activity that was stronger compared to ceralasertib, another ATR inhibitor, in several tumor models. This activity was present in both DDR-proficient and DDR-deficient lymphoma models. Furthermore, elimusertib had synergistic antitumor activity in combination with copanlisib. ConclusionsPotent antitumor activity of elimusertib was demonstrated in several lymphoma models which is associated with high expression of gene transcripts coding for proteins that are involved in DDR and cell cycle regulation. Combination of ATR and PI3K inhibition by treatment with elimusertib and copanlisib had synergistic efficacy providing a potential new treatment option for lymphoma patients. Translational relevanceThe DNA damage response (DDR) is often deregulated in lymphoma cells. Here, we characterized the activity of elimusertib, an inhibitor of the ataxia telangiectasia and Rad3-related kinase (ATR) that is involved in the DDR. Elimusertib was demonstrated to exhibit anti-lymphoma activity across several lymphoma cell lines and tumor models. Copanlisib is an inhibitor of PI3K kinase family which has also shown activity in various lymphomas. Combined treatment with elimusertib and copanlisib resulted in a synergistic antitumor effect in lymphoma models. The combination of elimusertib and copanlisib could potentially constitute a new chemotherapy-free treatment option for lymphomas.

cancer biology↗

Assessment of lisavanbulin (BAL101553) as an anti-lymphoma agent

Microtubules are major components of the cellular cytoskeleton, ubiquitously founded in all eukaryotic cells. They are involved in mitosis, cell motility, intracellular protein and organelle transport, and maintenance of cytoskeletal shape. Avanbulin (BAL27862) is a microtubule-targeted agent (MTA) that promotes tumor cell death by destabilization of microtubules. Due to its unique binding to the colchicine site of tubulin, differently from other MTAs, avanbulin has previously shown activity in solid tumor cell lines. Its prodrug, lisavanbulin (BAL101553), has shown early signs of clinical activity, especially in tumors with high EB1 expression. Here, we assessed the preclinical anti-tumor activity of avanbulin in diffuse large B cell lymphoma (DLBCL) and the pattern of expression of EB1 in DLBCL cell lines and clinical specimens. Avanbulin showed a potent in vitro anti-lymphoma activity, which was mainly cytotoxic with potent and rapid apoptosis induction. Median IC50 was around 10nM in both activated B cell like (ABC) and germinal center B cell like (GCB) DLBCL. Half of the cell lines tested showed an induction of apoptosis already in the first 24h of treatment, the other half in the first 48h. EB1 showed expression in DLBCL clinical specimens, opening the possibility for a cohort of patients that could potentially benefit from treatment with lisavanbulin. These data show the basis for further preclinical and clinical evaluation of lisavanbulin in the lymphoma field.

cancer biology↗

ERBB4-mediated signaling is a mediator of resistance to BTK and PI3K inhibitors in B cell lymphoid neoplasms

BTK and PI3K inhibitors are among the drugs approved for the treatment of patients with lymphoid neoplasms. Although active, their ability to lead as single agents to long-lasting complete remission is rather limited especially in the lymphoma setting. This indicates that tumor cells often develop resistance to the drugs. Here, we show that the overexpression of ERBB4 and its ligands represents a modality for B cell neoplastic cells to bypass the anti-tumor activity of BTK and PI3K inhibitors and that targeted pharmacological interventions can restore sensitivity to the small molecules. We started from a marginal zone lymphoma (MZL) cell line, Karpas-1718, kept under prolonged exposure to the PI3K{delta} inhibitor idelalisib until acquisition of resistance, or with no drug. Cells underwent transcriptome, miRNA and methylation profiling, whole exome sequencing, and pharmacological screening which led to the identification of the overexpression of ERBB4 and its ligands HBEGF and NRG2 in the resistant cells. Cellular and genetic experiments demonstrated the involvement of this axis in blocking the anti-tumor activity of various BTK and PI3K inhibitors, currently used in the clinical setting. Addition of recombinant HBEGF induced resistance to BTK and PI3K inhibitors in parental cells but also in additional lymphoma models. Combination with the ERBB inhibitor lapatinib was beneficial in resistant cells and in other lymphoma models already expressing the identified resistance factors. Multi-omics analysis underlined that an epigenetic reprogramming affected the expression of the resistance-related factors, and pretreatment with demethylating agents or EZH2 inhibitors overcame the resistance. Resistance factors were shown to be expressed in clinical samples, further extending the findings of the study. In conclusions, we identified a novel ERBB4-driven mechanism of resistance to BTK and PI3K inhibitors and treatments that appear to overcome it. Key pointsO_LIA mechanism of secondary resistance to the PI3K{delta} and BTK inhibitors in B cell neoplasms driven by secreted factors. C_LIO_LIResistance can be reverted by targeting ERBB signaling. C_LI

cancer biology↗

A first-in-class Wiskott-Aldrich syndrome protein (WASp) activator with anti-tumor activity in hematological cancers

Hematological cancers are among the most common cancers in adults and in children. Despite significant improvements in therapies, many patients still succumb to the disease, therefore, novel therapies are needed. The Wiskott-Aldrich syndrome protein (WASp) family proteins regulate actin assembly in conjunction with the Arp2/3 complex, a ubiquitous nucleation factor. WASp is expressed exclusively in hematopoietic cells and exists in two allosteric conformations, auto-inhibited and active conformations. Here, we describe the development of EG-011, a first-in-class small molecule activator of the WASp auto-inhibited form. EG-011 possesses in vitro and in vivo anti-tumor activity as single agent in lymphoma, leukemia and multiple myeloma, including models of secondary resistance to PI3K, BTK and proteasome inhibitors. The in vitro activity was confirmed in a lymphoma xenograft. Actin polymerization induced by EG-011 was demonstrated with multiple techniques. Transcriptome analysis highlighted homology with drugs inducing actin polymerization. Key pointsO_LIEG-011 is a novel small molecule with anti-tumor activity in hematological cancers, including resistant lymphoma and multiple myeloma models C_LIO_LIEG-011 is a first-in-class small molecule activator of the auto-inhibited form of the Wiskott-Aldrich syndrome protein (WASp) C_LI

cancer biology↗