Biology subjects

Heymann, D.

Publications and source records attributed to Heymann, D..

4 recordsLinked to original sources

bioRxiv2023

A personalized medicine approach identifies enasidenib as an efficient treatment for IDH2 mutant chondrosarcoma

BackgroundSarcomas represent an extensive group of malignant diseases affecting mesodermal tissues. Among sarcomas, the clinical management of chondrosarcomas remains a complex challenge, as high-grade tumors do not respond to current therapies. Mutations in the isocitrate dehydrogenase (IDH) 1 and 2 genes are among the most common mutations detected in chondrosarcomas and may represent a therapeutic opportunity. The presence of mutated IDH (mIDH) enzymes results in the accumulation of the oncometabolite 2-HG leading to molecular alterations that contribute to drive tumor growth. MethodsWe developed a personalized medicine strategy based on the targeted NGS/Sanger sequencing of sarcoma samples (n=6) and the use of matched patient-derived cell lines as a drug-testing platform. The anti-tumor potential of IDH mutations found in two chondrosarcoma cases was analyzed in vitro, in vivo and molecularly (transcriptomic and DNA methylation analyses). FindingsWe treated several chondrosarcoma models with specific mIDH1/2 inhibitors. Among these treatments, only the mIDH2 inhibitor enasidenib was able to decrease 2-HG levels and efficiently reduce the viability of mIDH2 chondrosarcoma cells. Importantly, oral administration of enasidenib in xenografted mice resulted in a complete abrogation of tumor growth. Enasidenib induced a profound remodeling of the transcriptomic landscape not associated to changes in the 5mC methylation levels and its anti-tumor effects were associated with the repression of proliferative pathways such as those controlled by E2F factors. InterpretationOverall, this work provides the first preclinical evidence for the use of enasidenib to treat mIDH2 chondrosarcomas. FundingSpanish Research Agency (grants PID2019-106666RB-I00; PI20CIII/00020; DTS18CIII/00005; CB16/12/00390; CB06/07/1009; CB19/07/00057). RESEARCH IN CONTEXTO_ST_ABSEvidence before this studyC_ST_ABSSarcomas represent an extensive group of malignant diseases affecting mesodermal tissues. The genomic nature of most sarcoma subtypes, displaying high inter- and intra-tumor heterogeneity with few recurrent driver mutations in a small portion of patients, makes these tumors especially indicated for personalized treatment approaches. For optimal development of these personalized protocols and a more efficient translation to the clinic, it is necessary to create patient-derived models suitable for testing the efficiency of candidate therapies. These strategies might be especially indicated for chondrosarcomas, a subtype of bone sarcoma that is inherently resistant to current therapies. Added value of this studyTo develop a personalized medicine strategy for sarcomas we have applied targeted sequencing protocols to detect druggable mutations in a collection of sarcomas cases with available patient-derived models. Among those potential druggable alterations detected in patient samples and avatar cell lines, we found IDH mutations in two chondrosarcomas. The presence of mutated IDH enzymes results in the accumulation of the oncometabolite 2-HG which contributes to driving tumor growth. In vitro and in vivo experiments evidenced the anti-tumor potential of the IDH mutant inhibitor enasidenib for the treatment of IDH2 mutant chondrosarcomas. Our transcriptomic and epigenomic analyses show that the mechanism of action of this drug is associated with the repression of proliferative pathways rather than with the promotion of tumor differentiation. Implications of all the available evidenceThis study suggests that enasidenib may represent an efficient therapeutic alternative for mutant IDH2 chondrosarcomas. This anti-proliferative mechanism of action of this drug may be especially relevant in dedifferentiated chondrosarcomas where reversal of this phenotype is not possible. In addition, this work provides support for the use of sarcoma patient-derived lines as avatar models capable of predicting (pre)-clinical responses in personalized medicine strategies.

cancer biology↗

bioRxiv2022

Specific targeting of inflammatory osteoclastogenesis by the probiotic yeast S. boulardii CNCM I-745 reduces bone loss in osteoporosis

Bone destruction is a hallmark of chronic inflammation, and bone-resorbing osteoclasts arising under such a condition differ from steady-state ones. However, osteoclast diversity remains poorly explored. Here, we combined transcriptomic profiling, differentiation assays and in vivo analysis in mouse to decipher specific traits for inflammatory and steady state osteoclasts. We identified and validated the pattern-recognition receptors (PRR) TLR2, Dectin-1 and Mincle, all involved in yeast recognition as major regulators of inflammatory osteoclasts. We showed that administration of the yeast probiotic Saccharomyces boulardi CNCM I-745 (Sb) in vivo reduced bone loss in OVX but not sham mice by reducing inflammatory osteoclasts. This beneficial impact of Sb is mediated by the regulation of the inflammatory environment required for the generation of inflammatory osteoclasts. We also showed that Sb derivatives as well as agonists of TLR2, Dectin-1 and Mincle specifically inhibited directly the differentiation of inflammatory but not steady state osteoclasts in vitro. These findings demonstrate a preferential use of the PRR-associated costimulatory differentiation pathway by inflammatory osteoclasts, thus enabling their specific inhibition, which opens new therapeutic perspectives for inflammatory bone loss.

physiology↗

bioRxiv2021

The P2RX7B splice variant modulates osteosarcoma cell behaviour and metastatic properties

Osteosarcoma (OS) is the most common type of primary bone cancer affecting children and adolescents. OS has a high propensity to spread, meaning the disease is often incurable and fatal. There have been no improvements in survival rates for decades. This highlights an urgent need for development of novel therapeutic strategies. In this study, we have produced in vitro and in vivo data that demonstrates the role of purinergic signalling, specifically, the B isoform of the purinergic receptor P2RX7 (herein termed " P2RX7B"), in OS progression and metastasis. Our data shows that P2RX7B expression confers a survival advantage in TE85+P2RX7B and MNNG-HOS+ P2RX7B human OS cell lines in vitro that is minimised following treatment with A740003, a specific P2RX7 antagonist. P2RX7B expression reduced cell adhesion and P2RX7B activation promoted invasion and migration in vitro, suggesting a probable metastatic phenotype. Using an in vivo OS xenograft model, MNNG-HOS+P2RX7B tumours exhibited ectopic bone formation that was abrogated with A740003 treatment. An increased metastatic phenotype was further demonstrated in vivo as expression of P2RX7B in primary tumour cells increased the propensity of the tumour to metastasise to the lungs. RNA-seq identified a novel gene axis, FN1/LOX/PDGFB/IGFBP3/BMP4, downregulated in response to A740003 treatment. In conclusion, our data indicates for the first time a role for P2RX7B in OS tumour growth, progression and metastasis. We show that P2RX7B is a potential therapeutic target in human OS. Novelty and ImpactWe provide evidence for the pro-tumorigenic role of the B isoform of the P2RX7 purinergic receptor in osteosarcoma (OS). In addition to increasing proliferation, P2RX7B increases the cancerous properties of OS cells, reducing adhesion and increasing migration and invasion. In vivo, P2RX7B does not affect primary tumour growth, but does lead to an increased propensity to metastasize. RNA-seq revealed a new axis of oncogenic genes inhibited by the P2RX7 antagonist and this data could potentially lead to new targets for OS treatment.

cancer biology↗

bioRxiv2020

Structure of a consensus chitin-binding domain revealed by solution NMR

Carbohydrate-binding proteins (CBPs) are a versatile group of proteins found in almost every organism on earth. CBPs are involved in enzymatic carbohydrate degradation and also serve as templating scaffolds in the exoskeleton of crustaceans and insects. One specific chitin-binding motif found across a wide range of arthropods exoskeletons is the "extended Rebers and Riddiford" consensus (R&R). However, how the R&R motif binds chitin is unclear. Here, we report the 3D structure and molecular level interactions of a chitin-binding domain (CBD-{gamma}) located in a CBP from the beak of the jumbo squid Dosidicus gigas. This CBP is one of four chitin-binding proteins identified in the beak mouthpart of D. gigas and is believed to interact with chitin to form a scaffold network that is infiltrated with a second set of structural proteins during beak maturation. We used solution state NMR spectroscopy to elucidate the molecular interactions between CBD-{gamma} and the soluble chitin derivative pentaacetyl-chitopentaose (PCP) and find that folding of this domain is triggered upon its interaction with PCP. To our knowledge, this is the first experimental 3D structure of a CBP containing the R&R consensus motif, which can be used as a template to understand in more details the role of the R&R motif found in a wide range of CBP-chitin complexes. The present structure also provides molecular information for biomimetic synthesis of graded biomaterials using aqueous-based chemistry and biopolymers.

biochemistry↗