Chiara Ambrogio

Università degli Studi di Torino | UNITO · Dipartimento di Biotecnologie Molecolari e Scienze per la Salute

Anaplastic Large Cell Lymphoma (ALCL) is a subtype of non-Hodgkin lymphoma frequently driven by the chimeric tyrosine kinase NPM-ALK, generated by the t (2,5)(p23;q35) translocation. While ALK+ ALCL belongs to mature T cell lymphomas, loss of T cell identity is observed in the majority of ALCL secondary to a transcriptional and epigenetic repressiv...

The Anti-Programmed Cell Death Protein-1/ Programmed Death-Ligand 1 Me-Too Drugs Tsunami: Hard To Be Millennials Among Baby Boomers

Constitutive KRAS signalling drives tumorigenesis across several cancer types. In non-small-cell lung cancer (NSCLC) activating KRAS mutations occur in ~30% of cases, and the glycine to cysteine substitution at codon 12 (G12C) is the most common KRAS alteration. Although KRAS mutations have been considered undruggable for over 40 years, the recent...

Background Neuroblastoma is the most common extracranial solid tumor of childhood¹ and accounts for 12-15% of cancer-related deaths in children.² The survival of patients with refractory or relapsed neuroblastoma remains dismal.³ In neuroblastoma, chimeric antigen receptor (CAR) T cells against GD2 have shown encouraging clinical results, but relap...

Introduction Brain metastases (BM) severely impact the prognosis and quality of life of patients with non-small cell lung cancer (NSCLC). Recently, molecularly targeted agents have shown promising activity against BM in NSCLC patients whose primary tumors carry ‘druggable’ mutations. However, it remains critical to identify specific pathogenic alte...

Brain metastases (BM) severely impact the prognosis and quality of life of patients with non-small cell lung cancer (NSCLC). To identify targetable drivers of NSCLC-BM, we profiled somatic copy number alterations (SCNAs) in 51 matched pairs of primary NSCLC and BM samples from 33 patients with lung adenocarcinoma (LUAD) and 18 patients with lung sq...

Purpose: Activating missense mutations of KRAS are the most frequent oncogenic driver events in lung adenocarcinoma (LUAD). However, KRAS isoforms are highly heterogeneous, and data on the potential isoform-dependent therapeutic vulnerabilities are still lacking. Experimental design: We developed an isogenic cell-based platform to compare the on...

Background and aims Acinar to Ductal Metaplasia (ADM) is the prerequisite for the initiation of Kras-driven pancreatic adenocarcinoma (PDAC) and candidate genes regulating this process are emerging from GWAS studies. The adaptor protein p130Cas emerged as a potential PDAC susceptibility gene and a Kras-synthetic lethal interactor in pancreatic cell...

The advent of high-throughput sequencing has allowed to profoundly interrogate the molecular landscape of non-small cell lung cancer (NSCLC) in the last years. These findings constitute the opportunity to better stratify these patients in order to address specific treatments to well-defined oncogene-restricted subgroups. Among them, BRAF-mutated lu...

Anaplastic large cell lymphomas (ALCLs) frequently carry oncogenic fusions involving the anaplastic lymphoma kinase (ALK) gene. Targeting ALK using tyrosine kinase inhibitors (TKIs) is a therapeutic option in cases relapsed after chemotherapy, but TKI resistance may develop. By applying genomic loss-of-function screens, we identified PTPN1 and PTPN...

The protein K-Ras functions as a molecular switch in signaling pathways regulating cell growth. In the human mitogen-activated protein kinase (MAPK) pathway, which is implicated in many cancers, multiple K-Ras proteins are thought to assemble at the cell membrane with Ras effector proteins from the Raf family. Here we propose an atomistic structura...

The ALK inhibitor crizotinib showed promising therapeutic efficacy for relapsed/refractory Anaplastic Large Cell Lymphoma (R/R ALCL). However, a fraction of ALK+ R/R ALCL patients do not achieve complete remission due to crizotinib resistance that develops within the first 3 months of therapy. In patients that achieve complete remission, crizotinib...

RAS gene mutations are the most frequent oncogenic event in lung cancer. They activate multiple RAS-centric signaling networks among them the MAPK, PI3K and RB pathways. Within the MAPK pathway ERK1/2 proteins exert a bottleneck function for transmitting mitogenic signals and activating cytoplasmic and nuclear targets. In view of disappointing anti...

The discovery of oncogenic driver mutations led to the development of targeted therapies with non-small cell lung cancer (NSCLC) being a paradigm for precision medicine in this setting. Nowadays, the number of clinical trials focusing on targeted therapies for uncommon drivers is growing exponentially, emphasizing the medical need for these patient...

Introduction: Anaplastic large-cell lymphomas (ALCL) frequently carry oncogenic fusions involving the anaplastic lymphoma kinase (ALK) gene. The ALK fusions activate several signaling pathways, promoting cell growth, migration, and survival. Chemotherapy is the standard treatment for ALCL patients, but about 30% of patients relapse. Targeting ALK u...

Introduction: EML4-ALK translocations are detected in 4-8 % of non-small cell lung cancer (NSCLC). While different EML4-ALK variants are defined by different breakpoints in the EML4 gene, most frequently located in intron 6 or 13, ALK breakpoint is almost invariably in intron 19. Rare reports describe EML4-ALK translocations with breakpoints in int...

Platinum-based chemotherapy in combination with immune-checkpoint inhibitors is the current standard of care for patients with advanced lung adenocarcinoma (LUAD). However, tumor progression evolves in most cases. Therefore, predictive biomarkers are needed for better patient stratification and for the identification of new therapeutic strategies,...

The protein K-Ras functions as a molecular switch in signaling pathways regulating cell growth. In the MAPK pathway, which is implicated in many cancers, multiple K-Ras proteins are thought to assemble at the cell membrane with Ras-effector proteins from the Raf family. Here we propose an atomistic structural model for such an assembly. Our startin...

Assembly of RAS molecules into complexes at the cell membrane is critical for RAS signaling. We previously showed that oncogenic KRAS codon 61 mutations increase its affinity for RAF, raising the possibility that KRASQ61H, the most common KRAS mutation at codon 61, upregulates RAS signaling through mechanisms at the level of RAS assemblies. We show...

Background KRAS mutations are the most frequent oncogenic aberration in lung adenocarcinoma. KRAS mutant isoforms differentially shape tumour biology and influence drug responses. This heterogeneity challenges the development of effective therapies for patients with KRAS-driven non-small cell lung cancer (NSCLC). Methods We developed an integrativ...

In T lymphocytes, the Wiskott-Aldrich Syndrome protein (WASP) and WASP-interacting-protein (WIP) regulate T cell antigen receptor (TCR) signaling, but their role in lymphoma is largely unknown. Here we show that the expression of WASP and WIP is frequently low or absent in anaplastic large cell lymphoma (ALCL) compared to other T cell lymphomas. In...

Purpose: BRAF mutations are divided into functional classes based on signaling mechanism and kinase activity: V600-mutant kinase-activating monomers (class I), kinase-activating dimers (class II), and kinase-inactivating heterodimers (class III). The relationship between functional class and disease characteristics in BRAF-mutant non-small cell lu...

Pulmonary ground-glass nodules (GGNs) are hazy radiological findings on computed tomography (CT). GGNs are detected more often in never-smokers. Retrospective and prospective studies have revealed that approximately 20% of pure GGNs and 40% of part-solid GGNs gradually grow or increase their solid components, whereas others remain stable for years....

Purpose: Despite the challenge to directly target mutant KRAS due to its high GTP affinity, some agents are under development against downstream signaling pathways, such as MEK inhibitors. However, it remains controversial whether MEK inhibitors can boost current chemotherapy in KRAS-mutant lung tumors in clinic. Considering the genomic heterogene...

Introduction KRAS is one of the most frequently mutated oncogenes in cancer and KRAS mutations are commonly associated with resistance to therapy and poor prognosis. KRAS is still not directly druggable, therefore current therapeutic strategies for KRAS mutant cancers aim at identifying susceptibilities in downstream signalling pathways. One unreso...

The Discoidin Domain Receptor 1 (DDR1) receptor tyrosine kinase performs pleiotropic functions in the control of cell adhesion, proliferation, survival, migration, and invasion. Aberrant DDR1 function as a consequence of either mutations or increased expression has been associated with various human diseases including cancer. Pharmacological inhibi...

The mechanism by which the wild-type KRAS allele imparts a growth inhibitory effect to oncogenic KRAS in various cancers, including lung adenocarcinoma (LUAD), is poorly understood. Here, using a genetically inducible model of KRAS loss of heterozygosity (LOH), we show that KRAS dimerization mediates wild-type KRAS-dependent fitness of human and mu...

The initiating oncogenic event in almost half of human lung adenocarcinomas is still unknown, a fact that complicates the development of selective targeted therapies. Yet these tumours harbour a number of alterations without obvious oncogenic function including BRAF-inactivating mutations. Inactivating BRAF mutants in lung predominate over the acti...

Targeted covalent small molecules have shown promise for cancers driven by KRAS G12C. Allosteric compounds that access an inducible pocket formed by movement of a dynamic structural element in KRAS, switch II, have been reported, but these compounds require further optimization to enable their advancement into clinical development. We demonstrate t...

Background: Lung cancer accounts for one in five cancer deaths worldwide and mutations in the gene encoding for the Kirsten rat sarcoma (KRAS) oncoprotein define the largest molecular subset of non-small cell lung cancer (NSCLC). These tumors are characterized by activated MAPK signaling, however, no targeted inhibitors of mutant KRAS or of downst...

Activation-induced cytidine deaminase (AID) is a B-cell-specific enzyme that targets immunoglobulin genes to initiate class switch recombination and somatic hypermutation. In addition, through off-target activity, AID has a much broader effect on genomic instability by initiating oncogenic chromosomal translocations and mutations involved in the de...

Activating mutations in KRAS and EGFR, the two most frequent oncogenes in human lung adenocarcinoma, are mutually exclusive, a phenotype attributed to functional redundancy implying lack of positive selection. Employing a mouse model expressing EGFR(L858R) in advanced Kras(G12V)-driven tumors we show that their mutual exclusivity can be explained b...

Understanding the early evolution of cancer heterogeneity during the initial steps of tumorigenesis can uncover vulnerabilities of cancer cells that may be masked at later stages. We describe a comprehensive approach employing gene expression analysis in early lesions to identify novel therapeutic targets and the use of mouse models to test synthet...

Patients with advanced Kirsten rat sarcoma viral oncogene homolog (KRAS)-mutant lung adenocarcinoma are currently treated with standard chemotherapy because of a lack of efficacious targeted therapies. We reasoned that the identification of mediators of Kras signaling in early mouse lung hyperplasias might bypass the difficulties that are imposed b...

Key Points Rac1 and Cdc42 possess nonredundant roles in preventing apoptosis of NPM-ALK lymphoma cells. Simultaneous deletions of both Rac1 and Cdc42 prevents NPM-ALK lymphoma dissemination in vivo.

Most of the anaplastic large-cell lymphoma (ALCL) cases carry the t(2;5; p23;q35) that produces the fusion protein NPM-ALK (nucleophosmin-anaplastic lymphoma kinase). NPM-ALK-deregulated kinase activity drives several pathways that support malignant transformation of lymphoma cells. We found that in ALK-rearranged ALCL cell lines, NPM-ALK was distr...

Non-Small Cell Lung Cancer (NSCLC) harboring Anaplastic Lymphoma Kinase (ALK) gene rearrangements is successfully treated with ALK tyrosine kinase inhibitors (TKIs) for only a limited amount of time as most cases relapse due to the development of drug resistance. Here we show that a vaccine against ALK induced a strong and specific immune response...

Most of Anaplastic Large Cell Lymphoma (ALCL) cases carry the t(2;5; p23;q35) that produces the fusion protein nucleophosmin (NPM)-ALK. NPM provides an oligomerization domain that causes the spontaneous dimerization and ligand-independent activation of the ALK. NPM-ALK deregulated kinase activity drives several pathways involved in cellular prolife...

Telomeres are considered anti-cancer targets, as telomere maintenance above a minimum length is necessary for cancer growth. Telomerase abrogation in cancer-prone mouse models, however, only decreased tumor growth after several mouse generations when telomeres reach a critically short length, and this effect was lost upon p53 mutation. Here, we add...

In Saccharomyces cerevisiae, absence of the checkpoint kinase Mec1 (ATR) is viable upon mutations that increase the activity of the ribonucleotide reductase (RNR) complex. Whether this pathway is conserved in mammals remains unknown. Here we show that cells from mice carrying extra alleles of the RNR regulatory subunit RRM2 (Rrm2TG) present supraph...

Generation of genetically engineered mouse models (GEMMs) for chromosomal translocations in the endogenous loci by a knockin strategy is lengthy and costly. The CRISPR/Cas9 system provides an innovative and flexible approach for genome engineering of genomic loci in vitro and in vivo. Here, we report the use of the CRISPR/Cas9 system for engineerin...

Despite the pressing need for novel cancer treatments, our improved understanding of tumor biology is not being successfully translated into better therapies. Here we present a lentiviral vector that enables in vivo validation of cancer therapeutic targets when combined with existing cancer animal models that faithfully reproduce the natural histor...

Rearrangements involving the Anaplastic Lymphoma Kinase (ALK) gene are defining events in several tumors, including Anaplastic Large Cell Lymphoma (ALCL) and Non-Small Cell Lung Carcinoma (NSCLC). In such cancers, the oncogenic activity of ALK stimulates signaling pathways that induce cell transformation and promote tumor growth. In search for comm...

Cancer evolution is a process that is still poorly understood due to the lack of versatile in vivo longitudinal studies. By generating murine Non-Small Cell Lung Cancer (NSCLC) orthoallobanks and paired primary cell lines, we provide a detailed description of an in vivo, time-dependent cancer malignization process. We identify the acquisition of me...

BIM is a proapoptotic member of the Bcl-2 family. Here, we investigated the epigenetic status of the BIM locus in NPM/ALK+ anaplastic large cell lymphoma (ALCL) cell lines and in lymph node biopsies from NPM/ALK+ ALCL patients. We show that BIM is epigenetically silenced in cell lines and lymph node specimens and that treatment with the deacetylase...

In non-small cell lung cancer (NSCLC), receptor tyrosine kinases (RTKs) stand out among causal dominant oncogenes, and the ablation of RTK signaling has emerged as a novel tailored therapeutic strategy. Nonetheless, long-term RTK inhibition leads invariably to acquired resistance, tumor recurrence and metastatic dissemination. In ALK+ cell lines, i...

Spinal muscular atrophy (SMA) is a human disease caused by reduced levels of the Survival of Motor Neuron (SMN) protein, leading to progressive loss of motor neurons and muscular paralysis. However, it is still not very clear why these cells are specifically sensitive to SMN levels. Therefore, understanding which proteins may functionally interact...

The anaplastic lymphoma kinase (ALK) is a tyrosine kinase receptor that is involved in the pathogenesis of different types of human cancers, including neuroblastoma (NB). In NB, ALK overexpression, or point mutations, are associated with poor prognosis and advanced stage disease. Inhibition of ALK kinase activity by small-molecule inhibitors in lun...

In T lymphocytes, the internalization of the R2 chain of the IFN-γ receptor (IFN-γR2) prevents the switching-on of pro-apoptotic and anti-proliferative genes induced by the IFN-γ/STAT1 pathway. In fibroblasts, a critical role of controlling the IFN-γR2 internalization is played by the LI(255-256) intracellular motif. Here we show that, in human mal...

Most anaplastic large cell lymphomas (ALCL) express oncogenic fusion proteins derived from chromosomal translocations or inversions of the anaplastic lymphoma kinase (ALK) gene. Frequently ALCL carry the t(2;5) translocation, which fuses the ALK gene to the nucleophosmin (NPM1) gene. The transforming activity mediated by NPM-ALK fusion induces diff...

Proceedings: AACR 101st Annual Meeting 2010‐‐ Apr 17‐21, 2010; Washington, DC Lung cancer is the most common cancer in the world, and is lethal in 90% of the cases. In non-small cell lung cancer (NSCLC), deregulated receptor tyrosine kinases (RTKs) stand out among the causal dominant oncogenes. Consequently, the genomic and/or pharmacological abla...

Cell fusion is essential for fertilization, myotube formation, and inflammation. Macrophages fuse under various circumstances, but the molecular signals involved in the distinct steps of their fusion are not fully characterized. Using null mice and derived cells, we show that the protease MT1-MMP is necessary for macrophage fusion during osteoclast...

Transformed cells in lymphomas usually maintain the phenotype of the postulated normal lymphocyte from which they arise. By contrast, anaplastic large cell lymphoma (ALCL) is a T-cell lymphoma with aberrant phenotype because of the defective expression of the T-cell receptor and other T-cell-specific molecules for still undetermined mechanisms. The...