Biology subjects

Martins da Costa, B.

Publications and source records attributed to Martins da Costa, B..

5 recordsLinked to original sources

bioRxiv2026

A COJEC-chemotherapy resistant model of Th-ALK(F1174L)/MYCN neuroblastoma offers insights into tumour immune evasion and development of the bone marrow metastatic niche

Multi-agent COJEC chemotherapy is the main-stay of induction treatment for patients diagnosed with high-risk neuroblastoma. However, at least 10% of patients will be primary refractory to chemotherapy and only 50% achieve 5-year overall survival. The bone marrow is the most frequent site of metastasis in these patients. Novel approaches are required to improve response rates but the inter- and intra- patient tumour heterogeneity and dynamics of the neuroblastoma immune microenvironment makes anticipation of resistance phenotypes incredibly challenging. We present here a novel immunocompetent C57 Bl/6 model of Th-ALK(F1174L)/MYCN neuroblastoma, in which spontaneous abdominal tumours are driven by expression of mutant Anaplastic Lymphoma Kinase and over-expression of Mycn in the neural crest. We have used this model to generate a personalised dosing schedule inducing COJEC-chemotherapy resistance, in which individual mice receive chemotherapy cycles dependent upon the progression of their neuroblastoma tumours. Using both single cell RNA sequencing and spatial immunophenotyping gave us extraordinary precision in our comprehensive analysis of the tumour intrinsic and microenvironmental factors associated with COJEC resistance. We found that the resistance phenotype was driven by Cdk8 upregulation in adrenergic and mesenchymal tumour cells. Infiltration of immunosuppressive myeloid-derived immune cells and remodeling of the tumour-associated stroma further contributed to COJEC resistance. In the bone marrow we observed expansion of neutrophils and evidence of NETosis associated with micro-metastatic disease. Our results further endorse the development of CDK8-targeting therapeutics for neuroblastoma patients which might boost the anti-tumour immune response. Additional studies will be required to define the roles of neutrophils and neutrophil NETosis in neuroblastoma progression and metastasis. Our C57 Bl/6 model will be pivotal in future preclinical studies of immune-modulating therapeutics.

cancer biology↗

bioRxiv2025

Differential chromatin response to retinoic acid in neuroblastoma according to type of ATRX mutation

Neuroblastoma is a childhood cancer, arising in the developing sympathetic nervous system. Differentiation therapy with 13-cis-retinoic acid (RA) is routinely given to children with high-risk neuroblastoma in the minimal residual disease setting to prevent relapse, however there is little understanding of which patients benefit from RA therapy. ATRX alterations are identified in 10% of high-risk neuroblastomas and associated with poor outcomes. The commonest type of ATRX alterations in neuroblastoma are in-frame multi-exon deletions, followed by nonsense mutations predicted to result in loss-of-function (ATRX LoF). We treated paired ATRX wild-type and ATRX LoF neuroblastoma cell lines with RA and show that cells with ATRX LoF fail to upregulate direct RA target genes. Cells with ATRX LoF also show reduced chromatin accessibility at genes involved in differentiation and development following RA treatment. Conversely, neuroblastoma models with in-frame deletions mount a response to RA and show in-vitro sensitivity to RA. Taken together this shows that the mechanism of differentiation in ATRX-altered neuroblastoma depends on the type of ATRX alteration, with implications relating to both oncogenesis and therapeutic response.

cancer biology↗

bioRxiv2025

Alectinib enhances response to RBM39 degradation via SRPK1 inhibition

Precise control of pre-mRNA splicing is critical for transcriptome integrity, and its disruption is increasingly recognised as a vulnerability in cancer. Here, we identify a functional interplay between two key splicing regulators, RBM39 and serine/arginine protein kinase 1 (SRPK1), and show that dual targeting of these factors severely compromises splicing fidelity in high-risk neuroblastoma. We use the molecular glue indisulam to degrade RBM39 and repurpose the clinical ALK inhibitor alectinib which potently inhibits SRPK1. Co-treatment with indisulam and alectinib inhibited cell proliferation, induced apoptosis, and caused G2/M arrest in multiple cancer cell lines, including MYCN-amplified neuroblastoma. RNA sequencing revealed enhanced splicing defects preferentially in DNA repair and genome maintenance related genes following combination treatment, leading to R-loop accumulation and increased DNA damage. In the Th-MYCN/ALKF1174L neuroblastoma mouse model, combination therapy induced complete tumour regression and significantly improved survival rates compared with monotherapies. These findings demonstrate that combining indisulam and alectinib is a promising approach to treat aggressive malignancies such as high-risk neuroblastoma, exploiting the previously untapped polypharmacology of alectinib as a clinical RNA splicing inhibitor and supporting the therapeutic value of co-targeting interdependent splicing factors for synergistic benefit.

cancer biology↗

bioRxiv2022

COMBINATION THERAPIES TARGETING ALK-ABERRANT NEUROBLASTOMA IN PRECLINICAL MODELS.

BackgroundALK activating mutations are identified in approximately 10% of newly diagnosed neuroblastomas and ALK amplifications in a further 1-2% of cases. Lorlatinib, a third generation ALK inhibitor, will soon be given alongside induction chemotherapy for children with ALK-aberrant neuroblastoma. However, resistance to single agent treatment has been reported and therapies that improve the response duration are urgently required. We studied the preclinical combination of lorlatinib with chemotherapy, or with the MDM2 inhibitor, idasanutlin, as recent data has suggested that ALK inhibitor resistance can be overcome through activation of the p53-MDM2 pathway. AimsTo study the preclinical activity of ALK inhibitors alone and in combination with chemotherapy or idasanutlin. MethodsWe compared different ALK inhibitors in preclinical models prior to evaluating lorlatinib in combination with chemotherapy or idasanutlin. We developed a triple chemotherapy (CAV: cyclophosphamide, doxorubicin and vincristine) in vivo dosing schedule and applied this to both neuroblastoma genetically engineered mouse models (GEMM) and patient derived xenografts (PDX). ResultsLorlatinib in combination with chemotherapy was synergistic in immunocompetent neuroblastoma GEMM. Significant growth inhibition in response to lorlatinib was only observed in the ALK-amplified PDX model with the highest ALK expression. In this PDX lorlatinib combined with idasanutlin resulted in complete tumor regression and significantly delayed tumor regrowth. ConclusionOur study suggests that in neuroblastoma, high ALK expression could be associated with response to lorlatinib and either chemotherapy or idasanutlin. The synergy between MDM2 inhibition and ALK inhibition warrants further evaluation of this combination as a potential clinical approach for children with neuroblastoma. STATEMENT OF TRANSLATIONAL RELEVANCENeuroblastoma is a pediatric tumor of the developing sympathetic nervous system. Around 50% of high-risk neuroblastoma patients are curable. Mutations or amplification of Anaplastic Lymphoma Kinase (ALK) have emerged as a marker with which to further risk-stratify patients. The ALK inhibitor lorlatinib will soon be used alongside chemotherapy in upfront treatment of high-risk patients with ALK-aberrant disease. In this preclinical study, we used a panel of ALK aberrant neuroblastoma models to evaluate ALK inhibitors focusing on lorlatinib in combination with conventional chemotherapy and the small molecule MDM2 inhibitor idasanutlin. In both approaches we found synergy in models with high basal ALK expression without MAPK pathway alterations. We conclude that in neuroblastoma the level of ALK expression could be an additional biomarker predictive of clinical response to ALK inhibitors.

cancer biology↗

bioRxiv2020

Indisulam targets RNA splicing and metabolism to serve as a novel therapeutic strategy for high-risk neuroblastoma

Neuroblastoma is the most common solid tumour in childhood and prognosis remains poor for high-risk cases despite the use of multimodal treatment. Analysis of public drug sensitivity data showed neuroblastoma lines to be particularly sensitive to indisulam, a molecular glue that selectively targets RNA splicing factor RBM39 for proteosomal degradation via DCAF15-E3-ubiquitin ligase. In neuroblastoma models, indisulam induced rapid loss of RBM39, accumulation of splicing errors and growth inhibition in a DCAF15- dependent manner. Integrative analysis of RNAseq and proteomics data highlighted a distinct disruption to cell cycle and metabolism. Metabolic profiling demonstrated metabolome perturbations and mitochondrial dysfunction resulting from indisulam. Complete tumour without relapse was observed in both xenografts and the Th-MYCN transgenic model of neuroblastoma after indisulam treatment, with RBM39 loss confirmed in vivo. Our data imply that dual targeting of metabolism and RNA splicing with anti-cancer sulphonamides such as indisulam is a promising therapeutic approach for high-risk neuroblastoma.

cancer biology↗