Biology subjects

Zammarchi, F.

Publications and source records attributed to Zammarchi, F..

4 recordsLinked to original sources

bioRxiv2024

Lineage-dependence of the neuroblastoma surfaceome defines tumor cell state-dependent and independent immunotherapeutic targets

BackgroundNeuroblastoma is a heterogeneous disease with adrenergic (ADRN)- and therapy resistant mesenchymal (MES)-like cells driven by distinct transcription factor networks. Here, we investigate the expression of immunotherapeutic targets in each neuroblastoma subtype and propose pan-neuroblastoma and cell state specific targetable cell-surface proteins. MethodsWe characterized cell lines, patient-derived xenografts, and patient samples as ADRN-dominant or MES- dominant to define subtype-specific and pan-neuroblastoma gene sets. Targets were validated with ChIP- sequencing, immunoblotting, and flow cytometry in neuroblastoma cell lines and isogenic ADRN-to-MES transition cell line models. Finally, we evaluated the activity of MES-specific agents in vivo and in vitro. ResultsMost immunotherapeutic targets being developed for neuroblastoma showed significantly higher expression in the ADRN subtype with limited expression in MES-like tumor cells. In contrast, CD276 (B7-H3) and L1CAM maintained expression across both ADRN and MES states. We identified several receptor tyrosine kinases (RTKs) enriched in MES-dominant samples and showed that AXL targeting with ADCT-601 was potently cytotoxic in MES-dominant cell lines and showed specific anti-tumor activity in a MES cell line-derived xenograft. ConclusionsImmunotherapeutic strategies for neuroblastoma must address the potential of epigenetic downregulation of antigen density as a mechanism for immune evasion. We identified several RTKs as candidate MES-specific immunotherapeutic target proteins for the elimination of therapy-resistant cells. We hypothesize that the phenomena of immune escape will be less likely when targeting pan-neuroblastoma cell surface proteins such as B7-H3 and L1CAM, and/or dual targeting strategies that consider both the ADRN- and MES-cell states. Key PointsO_LICellular plasticity influences the abundance of immunotherapeutic targets. C_LIO_LISubtype-specific targets may be susceptible to epigenetically-mediated downregulation. C_LIO_LIImmunotherapeutic targets in development, B7-H3 and L1CAM, show "pan-subtype" expression. C_LI Importance of StudyNeuroblastoma is a lethal childhood malignancy that shows cellular plasticity in response to anti-cancer therapies. Several plasma membrane proteins are being developed as immunotherapeutic targets in this disease. Here we define which cell surface proteins are susceptible to epigenetically regulated downregulation during an adrenergic to mesenchymal cell state switch and propose immunotherapeutic strategies to anticipate and circumvent acquired immunotherapeutic resistance.

cancer biology↗

bioRxiv2023

A proteogenomic surfaceome study identifies DLK1 as an immunotherapeutic target in neuroblastoma

Cancer immunotherapies have produced remarkable results in B-cell malignancies; however, optimal cell surface targets for many solid cancers remain elusive. Here, we present an integrative proteomic, transcriptomic, and epigenomic analysis of tumor specimens along with normal tissues to identify biologically relevant cell surface proteins that can serve as immunotherapeutic targets for neuroblastoma, an often-fatal childhood cancer of the developing nervous system. We apply this approach to human-derived cell lines (N=9) and cell/patient-derived xenograft (N=12) models of neuroblastoma. Plasma membrane-enriched mass spectrometry identified 1,461 cell surface proteins in cell lines and 1,401 in xenograft models, respectively. Additional proteogenomic analyses revealed 60 high-confidence candidate immunotherapeutic targets and we prioritized Delta-like canonical notch ligand 1 (DLK1) for further study. High expression of DLK1 directly correlated with the presence of a super-enhancer spanning the DLK1 locus. Robust cell surface expression of DLK1 was validated by immunofluorescence, flow cytometry, and immunohistochemistry. Short hairpin RNA mediated silencing of DLK1 in neuroblastoma cells resulted in increased cellular differentiation. ADCT-701, a DLK1-targeting antibody-drug conjugate (ADC), showed potent and specific cytotoxicity in DLK1-expressing neuroblastoma xenograft models. Moreover, DLK1 is highly expressed in several adult cancer types, including adrenocortical carcinoma (ACC), pheochromocytoma/paraganglioma (PCPG), hepatoblastoma, and small cell lung cancer (SCLC), suggesting potential clinical benefit beyond neuroblastoma. Taken together, our study demonstrates the utility of comprehensive cancer surfaceome characterization and credentials DLK1 as an immunotherapeutic target. HighlightsO_LIPlasma membrane enriched proteomics defines surfaceome of neuroblastoma C_LIO_LIMulti-omic data integration prioritizes DLK1 as a candidate immunotherapeutic target in neuroblastoma and other cancers C_LIO_LIDLK1 expression is driven by a super-enhancer C_LIO_LIDLK1 silencing in neuroblastoma cells results in cellular differentiation C_LIO_LIADCT-701, a DLK1-targeting antibody-drug conjugate, shows potent and specific cytotoxicity in DLK1-expressing neuroblastoma preclinical models C_LI

cancer biology↗

bioRxiv2023

Targeting CD19-positive lymphomas with the antibody-drug conjugate (ADC) loncastuximab tesirine: preclinical evidence as single agent and as combinatorial approach

PurposeAntibody-drug conjugates (ADCs) represent one of the most successful therapeutic approaches introduced in clinical practice in the last years. Loncastuximab tesirine (ADCT-402) is a CD19 targeting ADC, in which the antibody is conjugated through a protease cleavable dipeptide linker to a pyrrolobenzodiazepine (PBD) dimer warhead (SG3199). Based on the results of a phase 2 study, loncastuximab tesirine was recently approved for adult patients with relapsed/refractory large B-cell lymphoma. Experimental DesignWe assessed the activity of loncastuximab tesirine in in vitro and in vivo models of lymphomas, correlated its activity with CD19 expression levels and identified combination partners providing synergy with loncastuximab tesirine. ResultsLoncastuximab tesirine was tested across 60 lymphoma cell lines. Loncastuximab tesirine has strong cytotoxic activity in B-cell lymphoma cell lines and the in vitro activity is correlated with CD19 expression level and with intrinsic sensitivity of cell lines to the ADCs warhead. Loncastuximab tesirine was more potent than other anti-CD19 ADCs (coltuximab ravtansine, huB4-DGN462), albeit the pattern of activity across cell lines was correlated. Loncastuximab tesirine activity also largely correlated with cell line sensitivity to R-CHOP. Combinatorial in vitro and in vivo experiments identified the benefit of adding loncastuximab tesirine to other agents, especially BCL2 and PI3K inhibitors. ConclusionsOur data support the further development of loncastuximab tesirine as single agent and in combination for patients affected by mature B-cell neoplasms. The results also highlight the importance of CD19 expression, and the existence of lymphoma populations characterized by resistance to multiple therapies.

cancer biology↗

bioRxiv2023

Targeting CD25-positive lymphoma cells with the antibody-drug conjugate camidanlumab tesirine as single agent or in combination with targeted agents

IntroductionCamidanlumab tesirine (ADCT-301) is a CD25 specific antibody-drug conjugate (ADC) employing SG3199, a highly cytotoxic DNA minor groove cross-linking pyrrolobenzodiazepine dimer. Camidanlumab tesirine has shown early clinical anti-tumor activity in various cancer types, including B- and T-cell lymphomas. Here, we assessed its preclinical activity as single agent in 57 lymphoma cell lines and in combination with selected drugs in T cell lymphomas-derived cell lines. MethodsCell lines were exposed to increasing concentrations of camidanlumab tesirine or to SG3199 for 96h followed by MTT proliferation assay. CD25 expression was measured both at cell surface level via fluorescence quantitation and at RNA level, using various technologies. Combination studies were performed exposing cells to increasing doses of camidanlumab tesirine and of additional drugs. ResultsCamidanlumab tesirine presented much stronger single agent in vitro cytotoxic activity in T than B cell lymphomas. In vitro activity was highly correlated with CD25 expression both at cell surface level and RNA level. Based on the higher activity in T cell lymphomas, camidanlumab tesirine-containing combinations were evaluated in cell lines derived from peripheral T cell lymphoma, ALK-pos or ALK-neg anaplastic large cell lymphoma. The most active combination partners were everolimus, copanlisib, venetoclax, vorinostat and pralatrexate, followed by bortezomib, romidepsin, bendamustine and 5-azacytidine. ConclusionThe strong camidanlumab tesirine single agent anti-lymphoma activity and the observed in vitro synergisms with targeted agents support further clinical development of camidanlumab tesirine and identify potential combination partners for future clinical studies.

cancer biology↗