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1.
Nature ; 592(7856): 789-793, 2021 04.
Article in English | MEDLINE | ID: mdl-33854235

ABSTRACT

D-type cyclins are central regulators of the cell division cycle and are among the most frequently deregulated therapeutic targets in human cancer1, but the mechanisms that regulate their turnover are still being debated2,3. Here, by combining biochemical and genetics studies in somatic cells, we identify CRL4AMBRA1 (also known as CRL4DCAF3) as the ubiquitin ligase that targets all three D-type cyclins for degradation. During development, loss of Ambra1 induces the accumulation of D-type cyclins and retinoblastoma (RB) hyperphosphorylation and hyperproliferation, and results in defects of the nervous system that are reduced by treating pregnant mice with the FDA-approved CDK4 and CDK6 (CDK4/6) inhibitor abemaciclib. Moreover, AMBRA1 acts as a tumour suppressor in mouse models and low AMBRA1 mRNA levels are predictive of poor survival in cancer patients. Cancer hotspot mutations in D-type cyclins abrogate their binding to AMBRA1 and induce their stabilization. Finally, a whole-genome, CRISPR-Cas9 screen identified AMBRA1 as a regulator of the response to CDK4/6 inhibition. Loss of AMBRA1 reduces sensitivity to CDK4/6 inhibitors by promoting the formation of complexes of D-type cyclins with CDK2. Collectively, our results reveal the molecular mechanism that controls the stability of D-type cyclins during cell-cycle progression, in development and in human cancer, and implicate AMBRA1 as a critical regulator of the RB pathway.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Cell Division , Cyclin D1/metabolism , Adaptor Proteins, Signal Transducing/genetics , Animals , CRISPR-Cas Systems , Cyclin D2/metabolism , Cyclin D3/metabolism , Cyclin-Dependent Kinase 2/metabolism , Cyclin-Dependent Kinase 4/antagonists & inhibitors , Cyclin-Dependent Kinase 6/antagonists & inhibitors , Female , Gene Knockout Techniques , Genes, Tumor Suppressor , HCT116 Cells , HEK293 Cells , Humans , Male , Mice , Neoplasms/genetics , Ubiquitin/metabolism
2.
Nature ; 592(7856): 799-803, 2021 04.
Article in English | MEDLINE | ID: mdl-33854232

ABSTRACT

Mammalian development, adult tissue homeostasis and the avoidance of severe diseases including cancer require a properly orchestrated cell cycle, as well as error-free genome maintenance. The key cell-fate decision to replicate the genome is controlled by two major signalling pathways that act in parallel-the MYC pathway and the cyclin D-cyclin-dependent kinase (CDK)-retinoblastoma protein (RB) pathway1,2. Both MYC and the cyclin D-CDK-RB axis are commonly deregulated in cancer, and this is associated with increased genomic instability. The autophagic tumour-suppressor protein AMBRA1 has been linked to the control of cell proliferation, but the underlying molecular mechanisms remain poorly understood. Here we show that AMBRA1 is an upstream master regulator of the transition from G1 to S phase and thereby prevents replication stress. Using a combination of cell and molecular approaches and in vivo models, we reveal that AMBRA1 regulates the abundance of D-type cyclins by mediating their degradation. Furthermore, by controlling the transition from G1 to S phase, AMBRA1 helps to maintain genomic integrity during DNA replication, which counteracts developmental abnormalities and tumour growth. Finally, we identify the CHK1 kinase as a potential therapeutic target in AMBRA1-deficient tumours. These results advance our understanding of the control of replication-phase entry and genomic integrity, and identify the AMBRA1-cyclin D pathway as a crucial cell-cycle-regulatory mechanism that is deeply interconnected with genomic stability in embryonic development and tumorigenesis.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Cyclin D/metabolism , Genomic Instability , S Phase , Animals , Cell Line , Cell Proliferation , Checkpoint Kinase 1/antagonists & inhibitors , Cyclin-Dependent Kinases/metabolism , DNA Replication , Gene Expression Regulation, Developmental , Genes, Tumor Suppressor , Humans , Mice , Mice, Knockout , Synthetic Lethal Mutations
3.
Am J Hum Genet ; 110(11): 1938-1949, 2023 11 02.
Article in English | MEDLINE | ID: mdl-37865086

ABSTRACT

Fanconi anemia (FA) is a clinically variable and genetically heterogeneous cancer-predisposing disorder representing the most common bone marrow failure syndrome. It is caused by inactivating predominantly biallelic mutations involving >20 genes encoding proteins with roles in the FA/BRCA DNA repair pathway. Molecular diagnosis of FA is challenging due to the wide spectrum of the contributing gene mutations and structural rearrangements. The assessment of chromosomal fragility after exposure to DNA cross-linking agents is generally required to definitively confirm diagnosis. We assessed peripheral blood genome-wide DNA methylation (DNAm) profiles in 25 subjects with molecularly confirmed clinical diagnosis of FA (FANCA complementation group) using Illumina's Infinium EPIC array. We identified 82 differentially methylated CpG sites that allow to distinguish subjects with FA from healthy individuals and subjects with other genetic disorders, defining an FA-specific DNAm signature. The episignature was validated using a second cohort of subjects with FA involving different complementation groups, documenting broader genetic sensitivity and demonstrating its specificity using the EpiSign Knowledge Database. The episignature properly classified DNA samples obtained from bone marrow aspirates, demonstrating robustness. Using the selected probes, we trained a machine-learning model able to classify EPIC DNAm profiles in molecularly unsolved cases. Finally, we show that the generated episignature includes CpG sites that do not undergo functional selective pressure, allowing diagnosis of FA in individuals with reverted phenotype due to gene conversion. These findings provide a tool to accelerate diagnostic testing in FA and broaden the clinical utility of DNAm profiling in the diagnostic setting.


Subject(s)
Fanconi Anemia , Humans , Fanconi Anemia/diagnosis , Fanconi Anemia/genetics , Fanconi Anemia/metabolism , Fanconi Anemia Complementation Group Proteins/genetics , Fanconi Anemia Complementation Group Proteins/metabolism , DNA Methylation/genetics , Proteins/genetics , DNA/metabolism
4.
EMBO J ; 40(10): e103563, 2021 05 17.
Article in English | MEDLINE | ID: mdl-33932238

ABSTRACT

The early secretory pathway and autophagy are two essential and evolutionarily conserved endomembrane processes that are finely interlinked. Although growing evidence suggests that intracellular trafficking is important for autophagosome biogenesis, the molecular regulatory network involved is still not fully defined. In this study, we demonstrate a crucial effect of the COPII vesicle-related protein TFG (Trk-fused gene) on ULK1 puncta number and localization during autophagy induction. This, in turn, affects formation of the isolation membrane, as well as the correct dynamics of association between LC3B and early ATG proteins, leading to the proper formation of both omegasomes and autophagosomes. Consistently, fibroblasts derived from a hereditary spastic paraparesis (HSP) patient carrying mutated TFG (R106C) show defects in both autophagy and ULK1 puncta accumulation. In addition, we demonstrate that TFG activity in autophagy depends on its interaction with the ATG8 protein LC3C through a canonical LIR motif, thereby favouring LC3C-ULK1 binding. Altogether, our results uncover a link between TFG and autophagy and identify TFG as a molecular scaffold linking the early secretion pathway to autophagy.


Subject(s)
Autophagosomes/metabolism , Autophagy-Related Protein-1 Homolog/metabolism , Intracellular Signaling Peptides and Proteins/metabolism , Microtubule-Associated Proteins/metabolism , Proteins/metabolism , Autophagy-Related Protein-1 Homolog/genetics , Blotting, Western , Fluorescent Antibody Technique , HEK293 Cells , HeLa Cells , Humans , Immunoprecipitation , Intracellular Signaling Peptides and Proteins/genetics , Microscopy, Electron, Transmission , Microtubule-Associated Proteins/genetics , Proteins/genetics , RNA Interference
5.
Int J Mol Sci ; 25(6)2024 Mar 13.
Article in English | MEDLINE | ID: mdl-38542223

ABSTRACT

Amyotrophic Lateral Sclerosis (ALS) is considered the prototype of motor neuron disease, characterized by motor neuron loss and muscle waste. A well-established pathogenic hallmark of ALS is mitochondrial failure, leading to bioenergetic deficits. So far, pharmacological interventions for the disease have proven ineffective. Trimetazidine (TMZ) is described as a metabolic modulator acting on different cellular pathways. Its efficacy in enhancing muscular and cardiovascular performance has been widely described, although its molecular target remains elusive. We addressed the molecular mechanisms underlying TMZ action on neuronal experimental paradigms. To this aim, we treated murine SOD1G93A-model-derived primary cultures of cortical and spinal enriched motor neurons, as well as a murine motor-neuron-like cell line overexpressing SOD1G93A, with TMZ. We first characterized the bioenergetic profile of the cell cultures, demonstrating significant mitochondrial dysfunction that is reversed by acute TMZ treatments. We then investigated the effect of TMZ in promoting autophagy processes and its impact on mitochondrial morphology. Finally, we demonstrated the effectiveness of TMZ in terms of the mitochondrial functionality of ALS-rpatient-derived peripheral blood mononuclear cells (PBMCs). In summary, our results emphasize the concept that targeting mitochondrial dysfunction may represent an effective therapeutic strategy for ALS. The findings demonstrate that TMZ enhances mitochondrial performance in motor neuron cells by activating autophagy processes, particularly mitophagy. Although further investigations are needed to elucidate the precise molecular pathways involved, these results hold critical implications for the development of more effective and specific derivatives of TMZ for ALS treatment.


Subject(s)
Amyotrophic Lateral Sclerosis , Mitochondrial Diseases , Trimetazidine , Mice , Animals , Humans , Amyotrophic Lateral Sclerosis/metabolism , Superoxide Dismutase-1/metabolism , Trimetazidine/pharmacology , Trimetazidine/therapeutic use , Mice, Transgenic , Leukocytes, Mononuclear/metabolism , Superoxide Dismutase/metabolism , Autophagy , Disease Models, Animal
6.
Mol Cancer ; 22(1): 149, 2023 09 07.
Article in English | MEDLINE | ID: mdl-37679813

ABSTRACT

The term "metastatic cascade" defines a process whereby few tumor cells complete a sequence of steps to leave the primary tumor to reach one or more sites elsewhere in the body, usually through the bloodstream to develop one or several metastases. Due to the nature and plasticity of cancer, unfortunately no specific and functional anti-metastatic drugs are available. In this Commentary, we are highlighting how four essential factors are able to induce adhesion-to-suspension transition (herein referred to as AST) in human cancer cells and how this process may play a key role in tumor metastasis. We further underlined the potential role of hematopoietic transcriptional regulators in reprogramming anchorage dependency of cells, supporting the possible targeting of AST factors as promising therapeutic strategy to overcome metastasis in solid tumor cells.


Subject(s)
Neoplasms , Humans , Neoplasms/genetics , Neoplasms/therapy
7.
Mol Cancer ; 22(1): 201, 2023 12 09.
Article in English | MEDLINE | ID: mdl-38071322

ABSTRACT

Autophagy is an essential cellular homeostasis pathway initiated by multiple stimuli ranging from nutrient deprivation to viral infection, playing a key role in human health and disease. At present, a growing number of evidence suggests a role of autophagy as a primitive innate immune form of defense for eukaryotic cells, interacting with components of innate immune signaling pathways and regulating thymic selection, antigen presentation, cytokine production and T/NK cell homeostasis. In cancer, autophagy is intimately involved in the immunological control of tumor progression and response to therapy. However, very little is known about the role and impact of autophagy in T and NK cells, the main players in the active fight against infections and tumors. Important questions are emerging: what role does autophagy play on T/NK cells? Could its modulation lead to any advantages? Could specific targeting of autophagy on tumor cells (blocking) and T/NK cells (activation) be a new intervention strategy? In this review, we debate preclinical studies that have identified autophagy as a key regulator of immune responses by modulating the functions of different immune cells and discuss the redundancy or diversity among the subpopulations of both T and NK cells in physiologic context and in cancer.


Subject(s)
Immunity, Innate , Neoplasms , Humans , Killer Cells, Natural , T-Lymphocytes , Neoplasms/therapy , Autophagy
8.
Biol Res ; 56(1): 19, 2023 Apr 28.
Article in English | MEDLINE | ID: mdl-37106439

ABSTRACT

BACKGROUND: AMBRA1 is an intrinsically disordered protein, working as a scaffold molecule to coordinate, by protein-protein interaction, many cellular processes, including autophagy, mitophagy, apoptosis and cell cycle progression. The zebrafish genome contains two ambra1 paralogous genes (a and b), both involved in development and expressed at high levels in the gonads. Characterization of the zebrafish paralogous genes mutant lines generated by CRISPR/Cas9 approach showed that ambra1b knockout leads to an all-male population. RESULTS: We demonstrated that the silencing of the ambra1b gene determines a reduction of primordial germ cells (PGCs), a condition that, in the zebrafish, leads to the development of all-male progeny. PGC reduction was confirmed by knockdown experiments and rescued by injection of ambra1b and human AMBRA1 mRNAs, but not ambra1a mRNA. Moreover, PGC loss was not rescued by injection with human AMBRA1 mRNA mutated in the CUL4-DDB1 binding region, thus suggesting that interaction with this complex is involved in PGC protection from loss. Results from zebrafish embryos injected with murine Stat3 mRNA and stat3 morpholino suggest that Ambra1b could indirectly regulate this protein through CUL4-DDB1 interaction. According to this, Ambra1+/- mice showed a reduced Stat3 expression in the ovary together with a low number of antral follicles and an increase of atretic follicles, indicating a function of Ambra1 in the ovary of mammals as well. Moreover, in agreement with the high expression of these genes in the testis and ovary, we found significant impairment of the reproductive process and pathological alterations, including tumors, mainly limited to the gonads. CONCLUSIONS: By exploiting ambra1a and ambra1b knockout zebrafish lines, we prove the sub-functionalization between the two paralogous zebrafish genes and uncover a novel function of Ambra1 in the protection from excessive PGC loss, which seems to require binding with the CUL4-DDB1 complex. Both genes seem to play a role in the regulation of reproductive physiology.


Subject(s)
Sex Differentiation , Zebrafish , Animals , Female , Humans , Male , Mice , Adaptor Proteins, Signal Transducing/metabolism , Germ Cells/metabolism , Mammals/genetics , Mammals/metabolism , Reproduction , RNA, Messenger/metabolism , Zebrafish/genetics , Zebrafish/metabolism , Zebrafish Proteins/genetics , Zebrafish Proteins/metabolism
9.
Acta Neuropathol ; 142(3): 537-564, 2021 09.
Article in English | MEDLINE | ID: mdl-34302498

ABSTRACT

Medulloblastoma (MB) is a childhood malignant brain tumour comprising four main subgroups characterized by different genetic alterations and rate of mortality. Among MB subgroups, patients with enhanced levels of the c-MYC oncogene (MBGroup3) have the poorest prognosis. Here we identify a previously unrecognized role of the pro-autophagy factor AMBRA1 in regulating MB. We demonstrate that AMBRA1 expression depends on c-MYC levels and correlates with Group 3 patient poor prognosis; also, knockdown of AMBRA1 reduces MB stem potential, growth and migration of MBGroup3 stem cells. At a molecular level, AMBRA1 mediates these effects by suppressing SOCS3, an inhibitor of STAT3 activation. Importantly, pharmacological inhibition of autophagy profoundly affects both stem and invasion potential of MBGroup3 stem cells, and a combined anti-autophagy and anti-STAT3 approach impacts the MBGroup3 outcome. Taken together, our data support the c-MYC/AMBRA1/STAT3 axis as a strong oncogenic signalling pathway with significance for both patient stratification strategies and targeted treatments of MBGroup3.


Subject(s)
Adaptor Proteins, Signal Transducing/genetics , Autophagy/drug effects , Cerebellar Neoplasms/drug therapy , Medulloblastoma/drug therapy , STAT3 Transcription Factor/genetics , Signal Transduction/drug effects , Animals , Cell Line, Tumor , Cell Movement/genetics , Child , Gene Knockdown Techniques , Humans , Mice , Mice, Inbred C57BL , Neoplastic Stem Cells , Prognosis , Proto-Oncogene Proteins c-myc/biosynthesis , Proto-Oncogene Proteins c-myc/genetics , Suppressor of Cytokine Signaling 3 Protein/antagonists & inhibitors
10.
EMBO J ; 35(16): 1793-809, 2016 08 15.
Article in English | MEDLINE | ID: mdl-27390127

ABSTRACT

Mitochondrial dynamics and functionality are linked to the autophagic degradative pathway under several stress conditions. However, the interplay between mitochondria and autophagy upon cell death signalling remains unclear. The T-cell receptor pathway signals the so-called activation-induced cell death (AICD) essential for immune tolerance regulation. Here, we show that this apoptotic pathway requires the inhibition of macroautophagy. Protein kinase-A activation downstream of T-cell receptor signalling inhibits macroautophagy upon AICD induction. This leads to the accumulation of damaged mitochondria, which are fragmented, display remodelled cristae and release cytochrome c, thereby driving apoptosis. Autophagy-forced reactivation that clears the Parkin-decorated mitochondria is as effective in inhibiting apoptosis as genetic interference with cristae remodelling and cytochrome c release. Thus, upon AICD induction regulation of macroautophagy, rather than selective mitophagy, ensures apoptotic progression.


Subject(s)
Apoptosis , Autophagy , Mitochondria/metabolism , Receptors, Antigen, T-Cell/metabolism , T-Lymphocytes/physiology , Animals , Cells, Cultured , Cytochromes c/metabolism , Humans , Mice, Inbred C57BL , Mitochondria/enzymology , Mitochondria/ultrastructure , Signal Transduction
11.
Semin Cancer Biol ; 47: 29-42, 2017 12.
Article in English | MEDLINE | ID: mdl-28655520

ABSTRACT

Mitochondria-shaping proteins control the dynamic equilibrium between fusion and fission of the mitochondrial network. Their balance is strictly required to regulate various processes, including the quality of mitochondria, cell metabolism, cell death, proliferation and cell migration. Alterations in these processes are frequently encountered in cancer, during both its onset and later progression, as evidence emerge connecting alterations in mitochondrial dynamics with cancer development. In recent years, novel therapeutic approaches to fight against different human tumors aim at exploiting the immune system's ability to specifically recognize tumor antigens, thus killing malignant cells in a process named immune-surveillance. Interestingly, data are accumulating on the role that mitochondrial dynamics play also for the correct function of both the innate and the adaptive immune system. By this review, we overview how mitochondrial dynamics can affect various processes during cancer development, acting directly on tumor cells or indirectly on cells responsible for tumor aggression and defence.


Subject(s)
Immunologic Surveillance , Mitochondria/metabolism , Mitochondrial Dynamics , Neoplasms/etiology , Neoplasms/metabolism , Animals , Apoptosis , Energy Metabolism , Humans , Immune System/cytology , Immune System/immunology , Immune System/metabolism , Mitochondria/drug effects , Molecular Targeted Therapy , Neoplasms/drug therapy , Reactive Oxygen Species/metabolism
12.
J Cell Sci ; 128(11): 2003-8, 2015 Jun 01.
Article in English | MEDLINE | ID: mdl-26034061

ABSTRACT

The activating molecule in Beclin-1-regulated autophagy (Ambra1), also known as autophagy/Beclin-1 regulator 1, is a highly intrinsically disordered and vertebrate-conserved adapter protein that is part of the autophagy signaling network. It acts in an early step of mammalian target of rapamycin complex 1 (mTORC1)-dependent autophagy by favouring formation of the autophagosome core complex. However, recent studies have revealed that Ambra1 can also coordinate a cell response upon starvation or other stresses that involve translocation of the autophagosome core complex to the endoplasmic reticulum (ER), regulative ubiquitylation and stabilization of the kinase ULK1, selective mitochondria removal and cell cycle downregulation. Moreover, Ambra1 itself appears to be targeted by a number of regulatory processes, such as cullin-dependent degradation, caspase cleavage and several modifications, ranging from phosphorylation to ubiquitylation. Altogether, this complex network of regulation highlights the importance of Ambra1 in crucial physiological events, including metabolism, cell death and cell division. In addition, Ambra1 is an important regulator of embryonic development, and its mutation or inactivation has been shown to correlate with several pathologies of the nervous system and to be involved in carcinogenesis. In this Cell Science at a Glance article and the accompanying poster, we discuss recent advances in the Ambra1 field, particularly the role of this pro-autophagic protein in cellular pathophysiology.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Carrier Proteins/metabolism , Animals , Apoptosis/physiology , Autophagy/physiology , Endoplasmic Reticulum/metabolism , Humans , Signal Transduction/physiology
13.
EMBO J ; 30(7): 1195-208, 2011 Apr 06.
Article in English | MEDLINE | ID: mdl-21358617

ABSTRACT

BECLIN 1 is a central player in macroautophagy. AMBRA1, a BECLIN 1-interacting protein, positively regulates the BECLIN 1-dependent programme of autophagy. In this study, we show that AMBRA1 binds preferentially the mitochondrial pool of the antiapoptotic factor BCL-2, and that this interaction is disrupted following autophagy induction. Further, AMBRA1 can compete with both mitochondrial and endoplasmic reticulum-resident BCL-2 (mito-BCL-2 and ER-BCL-2, respectively) to bind BECLIN 1. Moreover, after autophagy induction, AMBRA1 is recruited to BECLIN 1. Altogether, these results indicate that, in normal conditions, a pool of AMBRA1 binds preferentially mito-BCL-2; after autophagy induction, AMBRA1 is released from BCL-2, consistent with its ability to promote BECLIN 1 activity. In addition, we found that the binding between AMBRA1 and mito-BCL-2 is reduced during apoptosis. Thus, a dynamic interaction exists between AMBRA1 and BCL-2 at the mitochondria that could regulate both BECLIN 1-dependent autophagy and apoptosis.


Subject(s)
Autophagy , Carrier Proteins/biosynthesis , Gene Expression Regulation , Protein Interaction Mapping , Proto-Oncogene Proteins c-bcl-2/metabolism , Adaptor Proteins, Signal Transducing , Apoptosis Regulatory Proteins/metabolism , Beclin-1 , Cell Line , Endoplasmic Reticulum/metabolism , Humans , Membrane Proteins/metabolism , Mitochondrial Membranes/metabolism
14.
Clin Cancer Res ; 30(11): 2545-2557, 2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38551501

ABSTRACT

PURPOSE: Medulloblastoma (MB), the most common childhood malignant brain tumor, has a poor prognosis in about 30% of patients. The current standard of care, which includes surgery, radiation, and chemotherapy, is often responsible for cognitive, neurologic, and endocrine side effects. We investigated whether chimeric antigen receptor (CAR) T cells directed toward the disialoganglioside GD2 can represent a potentially more effective treatment with reduced long-term side effects. EXPERIMENTAL DESIGN: GD2 expression was evaluated on primary tumor biopsies of MB children by flow cytometry. GD2 expression in MB cells was also evaluated in response to an EZH2 inhibitor (tazemetostat). In in vitro and in vivo models, GD2+ MB cells were targeted by a CAR-GD2.CD28.4-1BBζ (CAR.GD2)-T construct, including the suicide gene inducible caspase-9. RESULTS: GD2 was expressed in 82.68% of MB tumors. The SHH and G3-G4 subtypes expressed the highest levels of GD2, whereas the WNT subtype expressed the lowest. In in vitro coculture assays, CAR.GD2 T cells were able to kill GD2+ MB cells. Pretreatment with tazemetostat upregulated GD2 expression, sensitizing GD2dimMB cells to CAR.GD2 T cells cytotoxic activity. In orthotopic mouse models of MB, intravenously injected CAR.GD2 T cells significantly controlled tumor growth, prolonging the overall survival of treated mice. Moreover, the dimerizing drug AP1903 was able to cross the murine blood-brain barrier and to eliminate both blood-circulating and tumor-infiltrating CAR.GD2 T cells. CONCLUSIONS: Our experimental data indicate the potential efficacy of CAR.GD2 T-cell therapy. A phase I/II clinical trial is ongoing in our center (NCT05298995) to evaluate the safety and therapeutic efficacy of CAR.GD2 therapy in high-risk MB patients.


Subject(s)
Gangliosides , Immunotherapy, Adoptive , Medulloblastoma , Receptors, Chimeric Antigen , Xenograft Model Antitumor Assays , Humans , Medulloblastoma/therapy , Medulloblastoma/immunology , Medulloblastoma/pathology , Medulloblastoma/genetics , Medulloblastoma/metabolism , Animals , Mice , Gangliosides/metabolism , Gangliosides/immunology , Receptors, Chimeric Antigen/immunology , Receptors, Chimeric Antigen/genetics , Receptors, Chimeric Antigen/metabolism , Immunotherapy, Adoptive/methods , Immunotherapy, Adoptive/adverse effects , Cell Line, Tumor , Child , Female , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Cerebellar Neoplasms/therapy , Cerebellar Neoplasms/immunology , Cerebellar Neoplasms/pathology , Cerebellar Neoplasms/metabolism , Morpholines/pharmacology , Male , Child, Preschool , Benzamides , Biphenyl Compounds , Pyridones
15.
J Exp Clin Cancer Res ; 42(1): 214, 2023 Aug 21.
Article in English | MEDLINE | ID: mdl-37599362

ABSTRACT

BACKGROUND: Medulloblastoma (MB) is the most common cerebellar malignancy during childhood. Among MB, MYC-amplified Group 3 tumors display the worst prognosis. MYC is an oncogenic transcription factor currently thought to be undruggable. Nevertheless, targeting MYC-dependent processes (i.e. transcription and RNA processing regulation) represents a promising approach. METHODS: We have tested the sensitivity of MYC-driven Group 3 MB cells to a pool of transcription and splicing inhibitors that display a wide spectrum of targets. Among them, we focus on THZ531, an inhibitor of the transcriptional cyclin-dependent kinases (CDK) 12 and 13. High-throughput RNA-sequencing analyses followed by bioinformatics and functional analyses were carried out to elucidate the molecular mechanism(s) underlying the susceptibility of Group 3 MB to CDK12/13 chemical inhibition. Data from International Cancer Genome Consortium (ICGC) and other public databases were mined to evaluate the functional relevance of the cellular pathway/s affected by the treatment with THZ531 in Group 3 MB patients. RESULTS: We found that pharmacological inhibition of CDK12/13 is highly selective for MYC-high Group 3 MB cells with respect to MYC-low MB cells. We identified a subset of genes enriched in functional terms related to the DNA damage response (DDR) that are up-regulated in Group 3 MB and repressed by CDK12/13 inhibition. Accordingly, MYC- and CDK12/13-dependent higher expression of DDR genes in Group 3 MB cells limits the toxic effects of endogenous DNA lesions in these cells. More importantly, chemical inhibition of CDK12/13 impaired the DDR and induced irreparable DNA damage exclusively in MYC-high Group 3 MB cells. The augmented sensitivity of MYC-high MB cells to CDK12/13 inhibition relies on the higher elongation rate of the RNA polymerase II in DDR genes. Lastly, combined treatments with THZ531 and DNA damage-inducing agents synergically suppressed viability of MYC-high Group 3 MB cells. CONCLUSIONS: Our study demonstrates that CDK12/13 activity represents an exploitable vulnerability in MYC-high Group 3 MB and may pave the ground for new therapeutic approaches for this high-risk brain tumor.


Subject(s)
Cerebellar Neoplasms , Medulloblastoma , Humans , Medulloblastoma/drug therapy , Medulloblastoma/genetics , Up-Regulation , Anilides , Cerebellar Neoplasms/drug therapy , Cerebellar Neoplasms/genetics , CDC2 Protein Kinase , Cyclin-Dependent Kinases/genetics
16.
Traffic ; 11(10): 1280-9, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20633243

ABSTRACT

Autophagy is a lysosome-mediated degradation pathway used by eukaryotes to recycle cytosolic components in both basal and stress conditions. Several genes have been described as regulators of autophagy, many of them being evolutionarily conserved from yeast to mammals. The study of autophagy-defective model systems has made it possible to highlight the importance of correctly functioning autophagic machinery in the development of invertebrates as, for example, during the complex events of fly and worm metamorphosis. In vertebrates, on the other hand, autophagy defects can be lethal for the animal if the mutated gene is involved in the early stages of development, or can lead to severe phenotypes if the mutation affects later stages. However, in both lower and higher eukaryotes, autophagy seems to be crucial during embryogenesis by acting in tissue remodeling in parallel with apoptosis. An increase of autophagic cells is, in fact, observed in the embryonic stages characterized by massive cell elimination. Moreover, autophagic processes probably protect cells during metabolic stress and nutrient paucity that occur during tissue remodeling. In light of such evidence, it can be concluded that there is a close interplay between autophagy and the processes of cell death, proliferation and differentiation that determine the development of higher eukaryotes.


Subject(s)
Autophagy , Embryonic Development , Animals , Caenorhabditis elegans/embryology , Caenorhabditis elegans/metabolism , Drosophila melanogaster/embryology , Drosophila melanogaster/metabolism , Female , Heart/embryology , Hematopoiesis , Metamorphosis, Biological , Mice , Neurogenesis , Osteogenesis , Ovarian Follicle/embryology , Ovarian Follicle/metabolism , Rats
17.
Front Cell Dev Biol ; 10: 1007641, 2022.
Article in English | MEDLINE | ID: mdl-36340043

ABSTRACT

Tumor-specific alterations in metabolism have been recognized to sustain the production of ATP and macromolecules needed for cell growth, division and survival in many cancer types. However, metabolic heterogeneity poses a challenge for the establishment of effective anticancer therapies that exploit metabolic vulnerabilities. Medulloblastoma (MB) is one of the most heterogeneous malignant pediatric brain tumors, divided into four molecular subgroups (Wingless, Sonic Hedgehog, Group 3 and Group 4). Recent progresses in genomics, single-cell sequencing, and novel tumor models have updated the classification and stratification of MB, highlighting the complex intratumoral cellular diversity of this cancer. In this review, we emphasize the mechanisms through which MB cells rewire their metabolism and energy production networks to support and empower rapid growth, survival under stressful conditions, invasion, metastasis, and resistance to therapy. Additionally, we discuss the potential clinical benefits of currently available drugs that could target energy metabolism to suppress MB progression and increase the efficacy of the current MB therapies.

18.
Mol Cell Oncol ; 8(4): 1945895, 2021.
Article in English | MEDLINE | ID: mdl-34616872

ABSTRACT

TRK-fused gene (TFG) is a protein implicated in multiple neurodegenerative diseases and oncogenesis. We have recently shown that, under starvation conditions, TFG contributes to spatial control of autophagy by facilitating Unc-51 like autophagy activating kinase 1 (ULK1)-microtubule-associated protein 1 light chain 3 gamma (MAP1LC3C) interaction to modulate omegasome and autophagosome formation. Defective TFG-mediated autophagy could thus be postulated as a possible contributor to ontogenesis or progression of TFG-related diseases.

19.
Diagnostics (Basel) ; 11(3)2021 Mar 09.
Article in English | MEDLINE | ID: mdl-33803216

ABSTRACT

Autophagy is a degradative process occurring in eukaryotic cells to maintain homeostasis and cell survival. After stressful conditions including nutrient deprivation, hypoxia or drugs administration, autophagy is induced to counteract pathways that could lead to cell death. In cancer, autophagy plays a paradoxical role, acting both as tumour suppressor-by cleaning cells from damaged organelles and inhibiting inflammation or, alternatively, by promoting genomic stability and tumour adaptive response-or as a pro-survival mechanism to protect cells from stresses such as chemotherapy. Neural-derived paediatric solid tumours represent a variety of childhood cancers with unique anatomical location, cellular origins, and clinical presentation. These tumours are a leading cause of morbidity and mortality among children and new molecular diagnostics and therapies are necessary for longer survival and reduced morbidity. Here, we review advances in our understanding of how autophagy modulation exhibits antitumor properties in experimental models of paediatric brain tumours, i.e., medulloblastoma (MB), ependymoma (EPN), paediatric low-grade and high-grade gliomas (LGGs, HGGs), atypical teratoid/rhabdoid tumours (ATRTs), and retinoblastoma (RB). We also discuss clinical perspectives to consider how targeting autophagy may be relevant in these specific paediatric tumours.

20.
Front Cell Dev Biol ; 8: 614178, 2020.
Article in English | MEDLINE | ID: mdl-33511121

ABSTRACT

Autophagy is an intracellular degradation process involved in the removal of proteins and damaged organelles by the formation of a double-membrane vesicle named autophagosome and degraded through fusion with lysosomes. An intricate relationship between autophagy and the endosomal and exosomal pathways can occur at different stages with important implications for normal physiology and human diseases. Recent researches have revealed that extracellular vesicles (EVs), such as exosomes, could have a cytoprotective role by inducing intracellular autophagy; on the other hand, autophagy plays a crucial role in the biogenesis and degradation of exosomes. Although the importance of these processes in cancer is well established, their interplay in tumor is only beginning to be documented. In some tumor contexts (1) autophagy and exosome-mediated release are coordinately activated, sharing the molecular machinery and regulatory mechanisms; (2) cancer cell-released exosomes impact on autophagy in recipient cells through mechanisms yet to be determined; (3) exosome-autophagy relationship could affect drug resistance and tumor microenvironment (TME). In this review, we survey emerging discoveries relevant to the exosomes and autophagy crosstalk in the context of cancer initiation, progression and recurrence. Consequently, we discuss clinical implications by targeting autophagy-exosomal pathway interaction and how this could lay a basis for the purpose of novel cancer therapeutics.

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