RESUMO
Many oncogenic insults deregulate RNA splicing, often leading to hypersensitivity of tumors to spliceosome-targeted therapies (STTs). However, the mechanisms by which STTs selectively kill cancers remain largely unknown. Herein, we discover that mis-spliced RNA itself is a molecular trigger for tumor killing through viral mimicry. In MYC-driven triple-negative breast cancer, STTs cause widespread cytoplasmic accumulation of mis-spliced mRNAs, many of which form double-stranded structures. Double-stranded RNA (dsRNA)-binding proteins recognize these endogenous dsRNAs, triggering antiviral signaling and extrinsic apoptosis. In immune-competent models of breast cancer, STTs cause tumor cell-intrinsic antiviral signaling, downstream adaptive immune signaling, and tumor cell death. Furthermore, RNA mis-splicing in human breast cancers correlates with innate and adaptive immune signatures, especially in MYC-amplified tumors that are typically immune cold. These findings indicate that dsRNA-sensing pathways respond to global aberrations of RNA splicing in cancer and provoke the hypothesis that STTs may provide unexplored strategies to activate anti-tumor immune pathways.
Assuntos
Antivirais/farmacologia , Imunidade/efeitos dos fármacos , Spliceossomos/metabolismo , Neoplasias de Mama Triplo Negativas/imunologia , Neoplasias de Mama Triplo Negativas/patologia , Imunidade Adaptativa/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Citoplasma/efeitos dos fármacos , Citoplasma/metabolismo , Feminino , Amplificação de Genes/efeitos dos fármacos , Humanos , Íntrons/genética , Camundongos , Terapia de Alvo Molecular , Proteínas Proto-Oncogênicas c-myc/metabolismo , Splicing de RNA/efeitos dos fármacos , Splicing de RNA/genética , RNA de Cadeia Dupla/metabolismo , Transdução de Sinais/efeitos dos fármacos , Spliceossomos/efeitos dos fármacos , Neoplasias de Mama Triplo Negativas/genéticaRESUMO
Pancreatic ductal adenocarcinoma (PDAC) is characterized by notorious resistance to current therapies attributed to inherent tumor heterogeneity and highly desmoplastic and immunosuppressive tumor microenvironment (TME). Unique proline isomerase Pin1 regulates multiple cancer pathways, but its role in the TME and cancer immunotherapy is unknown. Here, we find that Pin1 is overexpressed both in cancer cells and cancer-associated fibroblasts (CAFs) and correlates with poor survival in PDAC patients. Targeting Pin1 using clinically available drugs induces complete elimination or sustained remissions of aggressive PDAC by synergizing with anti-PD-1 and gemcitabine in diverse model systems. Mechanistically, Pin1 drives the desmoplastic and immunosuppressive TME by acting on CAFs and induces lysosomal degradation of the PD-1 ligand PD-L1 and the gemcitabine transporter ENT1 in cancer cells, besides activating multiple cancer pathways. Thus, Pin1 inhibition simultaneously blocks multiple cancer pathways, disrupts the desmoplastic and immunosuppressive TME, and upregulates PD-L1 and ENT1, rendering PDAC eradicable by immunochemotherapy.
Assuntos
Imunoterapia , Terapia de Alvo Molecular , Peptidilprolil Isomerase de Interação com NIMA/metabolismo , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/imunologia , Proteínas Adaptadoras de Transdução de Sinal/química , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/imunologia , Adenocarcinoma/patologia , Aloenxertos/imunologia , Motivos de Aminoácidos , Animais , Apoptose/efeitos dos fármacos , Antígeno B7-H1/metabolismo , Fibroblastos Associados a Câncer/metabolismo , Fibroblastos Associados a Câncer/patologia , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/imunologia , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Desoxicitidina/análogos & derivados , Desoxicitidina/farmacologia , Desoxicitidina/uso terapêutico , Sinergismo Farmacológico , Endocitose/efeitos dos fármacos , Transportador Equilibrativo 1 de Nucleosídeo/metabolismo , Humanos , Terapia de Imunossupressão , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Camundongos , Proteínas dos Microfilamentos/química , Proteínas dos Microfilamentos/metabolismo , Oncogenes , Organoides/efeitos dos fármacos , Organoides/patologia , Transdução de Sinais/efeitos dos fármacos , Análise de Sobrevida , Microambiente Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto , GencitabinaRESUMO
Cancer therapies kill tumors either directly or indirectly by evoking immune responses and have been combined with varying levels of success. Here, we describe a paradigm to control cancer growth that is based on both direct tumor killing and the triggering of protective immunity. Genetic ablation of serine protease inhibitor SerpinB9 (Sb9) results in the death of tumor cells in a granzyme B (GrB)-dependent manner. Sb9-deficient mice exhibited protective T cell-based host immunity to tumors in association with a decline in GrB-expressing immunosuppressive cells within the tumor microenvironment (TME). Maximal protection against tumor development was observed when the tumor and host were deficient in Sb9. The therapeutic utility of Sb9 inhibition was demonstrated by the control of tumor growth, resulting in increased survival times in mice. Our studies describe a molecular target that permits a combination of tumor ablation, interference within the TME, and immunotherapy in one potential modality.
Assuntos
Citotoxicidade Imunológica , Imunoterapia , Proteínas de Membrana/metabolismo , Neoplasias/imunologia , Neoplasias/terapia , Serpinas/metabolismo , Animais , Apoptose/efeitos dos fármacos , Neoplasias da Mama/imunologia , Neoplasias da Mama/patologia , Neoplasias da Mama/terapia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Citotoxicidade Imunológica/efeitos dos fármacos , Progressão da Doença , Feminino , Deleção de Genes , Granzimas/metabolismo , Imunidade/efeitos dos fármacos , Melanoma/patologia , Camundongos Endogâmicos C57BL , Neoplasias/prevenção & controle , Bibliotecas de Moléculas Pequenas/farmacologia , Células Estromais/efeitos dos fármacos , Células Estromais/patologia , Microambiente Tumoral/efeitos dos fármacosRESUMO
Problems arising during translation of mRNAs lead to ribosome stalling and collisions that trigger a series of quality control events. However, the global cellular response to ribosome collisions has not been explored. Here, we uncover a function for ribosome collisions in signal transduction. Using translation elongation inhibitors and general cellular stress conditions, including amino acid starvation and UV irradiation, we show that ribosome collisions activate the stress-activated protein kinase (SAPK) and GCN2-mediated stress response pathways. We show that the MAPKKK ZAK functions as the sentinel for ribosome collisions and is required for immediate early activation of both SAPK (p38/JNK) and GCN2 signaling pathways. Selective ribosome profiling and biochemistry demonstrate that although ZAK generally associates with elongating ribosomes on polysomal mRNAs, it specifically auto-phosphorylates on the minimal unit of colliding ribosomes, the disome. Together, these results provide molecular insights into how perturbation of translational homeostasis regulates cell fate.
Assuntos
Ribossomos/metabolismo , Estresse Fisiológico , Transportadores de Cassetes de Ligação de ATP/metabolismo , Anisomicina/farmacologia , Apoptose/efeitos dos fármacos , Dano ao DNA/efeitos da radiação , Ativação Enzimática , Humanos , MAP Quinase Quinase Quinases/deficiência , MAP Quinase Quinase Quinases/genética , MAP Quinase Quinase Quinases/metabolismo , Proteína Quinase 14 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 14 Ativada por Mitógeno/metabolismo , Fosforilação , Polirribossomos/metabolismo , Isoformas de Proteínas/deficiência , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Interferência de RNA , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/metabolismo , Transdução de Sinais , Raios Ultravioleta , eIF-2 Quinase/metabolismoRESUMO
New opportunities are needed to increase immune checkpoint blockade (ICB) benefit. Whereas the interferon (IFN)γ pathway harbors both ICB resistance factors and therapeutic opportunities, this has not been systematically investigated for IFNγ-independent signaling routes. A genome-wide CRISPR/Cas9 screen to sensitize IFNγ receptor-deficient tumor cells to CD8 T cell elimination uncovered several hits mapping to the tumor necrosis factor (TNF) pathway. Clinically, we show that TNF antitumor activity is only limited in tumors at baseline and in ICB non-responders, correlating with its low abundance. Taking advantage of the genetic screen, we demonstrate that ablation of the top hit, TRAF2, lowers the TNF cytotoxicity threshold in tumors by redirecting TNF signaling to favor RIPK1-dependent apoptosis. TRAF2 loss greatly enhanced the therapeutic potential of pharmacologic inhibition of its interaction partner cIAP, another screen hit, thereby cooperating with ICB. Our results suggest that selective reduction of the TNF cytotoxicity threshold increases the susceptibility of tumors to immunotherapy.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Imunoterapia , Fator de Necrose Tumoral alfa/metabolismo , Animais , Apoptose/efeitos dos fármacos , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/metabolismo , Linhagem Celular Tumoral , Humanos , Proteínas Inibidoras de Apoptose/metabolismo , Interferon gama/metabolismo , Estimativa de Kaplan-Meier , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias/mortalidade , Neoplasias/terapia , RNA Guia de Cinetoplastídeos/metabolismo , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Receptores de Interferon/deficiência , Receptores de Interferon/genética , Transdução de Sinais/efeitos dos fármacos , Fator 2 Associado a Receptor de TNF/deficiência , Fator 2 Associado a Receptor de TNF/genética , Fator de Necrose Tumoral alfa/farmacologia , Receptor de Interferon gamaRESUMO
Pathogenic and other cytoplasmic DNAs activate the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway to induce inflammation via transcriptional activation by IRF3 and nuclear factor κB (NF-κB), but the functional consequences of exposing cGAS to chromosomes upon mitotic nuclear envelope breakdown are unknown. Here, we show that nucleosomes competitively inhibit DNA-dependent cGAS activation and that the cGAS-STING pathway is not effectively activated during normal mitosis. However, during mitotic arrest, low level cGAS-dependent IRF3 phosphorylation slowly accumulates without triggering inflammation. Phosphorylated IRF3, independently of its DNA-binding domain, stimulates apoptosis through alleviating Bcl-xL-dependent suppression of mitochondrial outer membrane permeabilization. We propose that slow accumulation of phosphorylated IRF3, normally not sufficient for inducing inflammation, can trigger transcription-independent induction of apoptosis upon mitotic aberrations. Accordingly, expression of cGAS and IRF3 in cancer cells makes mouse xenograft tumors responsive to the anti-mitotic agent Taxol. The Cancer Genome Atlas (TCGA) datasets for non-small cell lung cancer patients also suggest an effect of cGAS expression on taxane response.
Assuntos
Apoptose , DNA/metabolismo , Nucleotidiltransferases/metabolismo , Animais , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Feminino , Humanos , Fator Regulador 3 de Interferon/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos NOD , Mitose , Neoplasias/tratamento farmacológico , Neoplasias/mortalidade , Neoplasias/patologia , Nucleossomos/metabolismo , Nucleotidiltransferases/antagonistas & inibidores , Nucleotidiltransferases/genética , Paclitaxel/farmacologia , Paclitaxel/uso terapêutico , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/isolamento & purificação , Transdução de Sinais , Taxa de Sobrevida , Ativação Transcricional , Proteína bcl-X/metabolismoRESUMO
CKIα ablation induces p53 activation, and CKIα degradation underlies the therapeutic effect of lenalidomide in a pre-leukemia syndrome. Here we describe the development of CKIα inhibitors, which co-target the transcriptional kinases CDK7 and CDK9, thereby augmenting CKIα-induced p53 activation and its anti-leukemic activity. Oncogene-driving super-enhancers (SEs) are highly sensitive to CDK7/9 inhibition. We identified multiple newly gained SEs in primary mouse acute myeloid leukemia (AML) cells and demonstrate that the inhibitors abolish many SEs and preferentially suppress the transcription elongation of SE-driven oncogenes. We show that blocking CKIα together with CDK7 and/or CDK9 synergistically stabilize p53, deprive leukemia cells of survival and proliferation-maintaining SE-driven oncogenes, and induce apoptosis. Leukemia progenitors are selectively eliminated by the inhibitors, explaining their therapeutic efficacy with preserved hematopoiesis and leukemia cure potential; they eradicate leukemia in MLL-AF9 and Tet2-/-;Flt3ITD AML mouse models and in several patient-derived AML xenograft models, supporting their potential efficacy in curing human leukemia.
Assuntos
Caseína Quinase Ialfa/antagonistas & inibidores , Leucemia Mieloide Aguda/tratamento farmacológico , Animais , Apoptose/efeitos dos fármacos , Caseína Quinase Ialfa/fisiologia , Proliferação de Células/efeitos dos fármacos , Quinase 9 Dependente de Ciclina/antagonistas & inibidores , Quinase 9 Dependente de Ciclina/fisiologia , Quinases Ciclina-Dependentes/antagonistas & inibidores , Quinases Ciclina-Dependentes/fisiologia , Proteínas de Ligação a DNA , Modelos Animais de Doenças , Elementos Facilitadores Genéticos/genética , Hematopoese , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Proteínas de Fusão Oncogênica/metabolismo , Proteínas Serina-Treonina Quinases , Proteínas Proto-Oncogênicas , Proteína Supressora de Tumor p53/fisiologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Widespread mRNA decay, an unappreciated feature of apoptosis, enhances cell death and depends on mitochondrial outer membrane permeabilization (MOMP), TUTases, and DIS3L2. Which RNAs are decayed and the decay-initiating event are unknown. Here, we show extensive decay of mRNAs and poly(A) noncoding (nc)RNAs at the 3' end, triggered by the mitochondrial intermembrane space 3'-to-5' exoribonuclease PNPT1, released during MOMP. PNPT1 knockdown inhibits apoptotic RNA decay and reduces apoptosis, while ectopic expression of PNPT1, but not an RNase-deficient mutant, increases RNA decay and cell death. The 3' end of PNPT1 substrates thread through a narrow channel. Many non-poly(A) ncRNAs contain 3'-secondary structures or bind proteins that may block PNPT1 activity. Indeed, mutations that disrupt the 3'-stem-loop of a decay-resistant ncRNA render the transcript susceptible, while adding a 3'-stem-loop to an mRNA prevents its decay. Thus, PNPT1 release from mitochondria during MOMP initiates apoptotic decay of RNAs lacking 3'-structures.
Assuntos
Apoptose , Exorribonucleases/metabolismo , Mitocôndrias/metabolismo , RNA Mensageiro/metabolismo , Regiões 3' não Traduzidas , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Citocromos c/metabolismo , Exorribonucleases/antagonistas & inibidores , Exorribonucleases/genética , Células HCT116 , Humanos , Membranas Mitocondriais/metabolismo , Conformação de Ácido Nucleico , Permeabilidade , Proteína I de Ligação a Poli(A)/química , Proteína I de Ligação a Poli(A)/metabolismo , Ligação Proteica , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Interferência de RNA , Estabilidade de RNA/efeitos dos fármacos , RNA Mensageiro/química , RNA Interferente Pequeno/metabolismo , RNA não Traduzido/química , RNA não Traduzido/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/farmacologiaRESUMO
Aging is a major risk factor for both genetic and sporadic neurodegenerative disorders. However, it is unclear how aging interacts with genetic predispositions to promote neurodegeneration. Here, we investigate how partial loss of function of TBK1, a major genetic cause for amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) comorbidity, leads to age-dependent neurodegeneration. We show that TBK1 is an endogenous inhibitor of RIPK1 and the embryonic lethality of Tbk1-/- mice is dependent on RIPK1 kinase activity. In aging human brains, another endogenous RIPK1 inhibitor, TAK1, exhibits a marked decrease in expression. We show that in Tbk1+/- mice, the reduced myeloid TAK1 expression promotes all the key hallmarks of ALS/FTD, including neuroinflammation, TDP-43 aggregation, axonal degeneration, neuronal loss, and behavior deficits, which are blocked upon inhibition of RIPK1. Thus, aging facilitates RIPK1 activation by reducing TAK1 expression, which cooperates with genetic risk factors to promote the onset of ALS/FTD.
Assuntos
Apoptose , Proteínas Serina-Treonina Quinases/metabolismo , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Adulto , Idoso , Envelhecimento , Animais , Apoptose/efeitos dos fármacos , Axônios/metabolismo , Comportamento Animal , Encéfalo/citologia , Encéfalo/metabolismo , Células Cultivadas , Humanos , Quinase I-kappa B/metabolismo , Camundongos , Camundongos Knockout , Microglia/citologia , Microglia/efeitos dos fármacos , Microglia/metabolismo , Fosforilação/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/deficiência , Proteínas Serina-Treonina Quinases/genética , Proteína Serina-Treonina Quinases de Interação com Receptores/deficiência , Proteína Serina-Treonina Quinases de Interação com Receptores/genética , Medula Espinal/metabolismo , Estaurosporina/farmacologia , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
The fusion oncoprotein CBFß-SMMHC, expressed in leukemia cases with chromosome 16 inversion, drives leukemia development and maintenance by altering the activity of the transcription factor RUNX1. Here, we demonstrate that CBFß-SMMHC maintains cell viability by neutralizing RUNX1-mediated repression of MYC expression. Upon pharmacologic inhibition of the CBFß-SMMHC/RUNX1 interaction, RUNX1 shows increased binding at three MYC distal enhancers, where it represses MYC expression by mediating the replacement of the SWI/SNF complex component BRG1 with the polycomb-repressive complex component RING1B, leading to apoptosis. Combining the CBFß-SMMHC inhibitor with the BET inhibitor JQ1 eliminates inv(16) leukemia in human cells and a mouse model. Enhancer-interaction analysis indicated that the three enhancers are physically connected with the MYC promoter, and genome-editing analysis demonstrated that they are functionally implicated in deregulation of MYC expression. This study reveals a mechanism whereby CBFß-SMMHC drives leukemia maintenance and suggests that inhibitors targeting chromatin activity may prove effective in inv(16) leukemia therapy.
Assuntos
Apoptose , Cromatina/metabolismo , Proteínas de Fusão Oncogênica/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-myc/metabolismo , Animais , Apoptose/efeitos dos fármacos , Azepinas/farmacologia , Azepinas/uso terapêutico , Benzimidazóis/farmacologia , Benzimidazóis/uso terapêutico , Linhagem Celular Tumoral , Proteínas Cromossômicas não Histona/química , Proteínas Cromossômicas não Histona/metabolismo , Inversão Cromossômica/efeitos dos fármacos , Subunidade alfa 2 de Fator de Ligação ao Core/química , Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , DNA/química , DNA/metabolismo , DNA Helicases/metabolismo , Modelos Animais de Doenças , Humanos , Estimativa de Kaplan-Meier , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/mortalidade , Leucemia Mieloide Aguda/patologia , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Nucleares/metabolismo , Proteínas de Fusão Oncogênica/metabolismo , Complexo Repressor Polycomb 1/metabolismo , Regiões Promotoras Genéticas , Ligação Proteica , Proteínas Proto-Oncogênicas c-myc/genética , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo , Triazóis/farmacologia , Triazóis/uso terapêuticoRESUMO
Recent discoveries provide a new hope that relapses of several types of cancer can be prevented by inducing ferroptosis.
Assuntos
Apoptose , Resistencia a Medicamentos Antineoplásicos , Ferro , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Animais , Apoptose/efeitos dos fármacos , Humanos , Prevenção SecundáriaRESUMO
Many chemotherapeutic drugs kill only a fraction of cancer cells, limiting their efficacy. We used live-cell imaging to investigate the role of p53 dynamics in fractional killing of colon cancer cells in response to chemotherapy. We found that both surviving and dying cells reach similar levels of p53, indicating that cell death is not determined by a fixed p53 threshold. Instead, a cell's probability of death depends on the time and levels of p53. Cells must reach a threshold level of p53 to execute apoptosis, and this threshold increases with time. The increase in p53 apoptotic threshold is due to drug-dependent induction of anti-apoptotic genes, predominantly in the inhibitors of apoptosis (IAP) family. Our study underlines the importance of measuring the dynamics of key players in response to chemotherapy to determine mechanisms of resistance and optimize the timing of combination therapy.
Assuntos
Antineoplásicos/farmacologia , Cisplatino/farmacologia , Resistencia a Medicamentos Antineoplásicos , Proteína Supressora de Tumor p53/metabolismo , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Proteínas Inibidoras de Apoptose , Regulação para CimaRESUMO
Venetoclax is a BH3 mimetic approved for treating chronic lymphocytic leukemia. Cancer cells are resistant to apoptosis but "primed for death" by elevated BCL-2, which binds to pro-apoptotic proteins and holds them in check. Venetoclax releases this antagonism and is the first approved drug to target a protein-protein interaction.
Assuntos
Antineoplásicos/uso terapêutico , Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico , Aprovação de Drogas , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Sulfonamidas/uso terapêutico , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/antagonistas & inibidores , Proteínas Reguladoras de Apoptose/metabolismo , Humanos , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-bcl-2/metabolismoRESUMO
KRAS is one of the most frequently mutated oncogenes in human cancer. Despite substantial efforts, no clinically applicable strategy has yet been developed to effectively treat KRAS-mutant tumors. Here, we perform a cell-line-based screen and identify strong synergistic interactions between cell-cycle checkpoint-abrogating Chk1- and MK2 inhibitors, specifically in KRAS- and BRAF-driven cells. Mechanistically, we show that KRAS-mutant cancer displays intrinsic genotoxic stress, leading to tonic Chk1- and MK2 activity. We demonstrate that simultaneous Chk1- and MK2 inhibition leads to mitotic catastrophe in KRAS-mutant cells. This actionable synergistic interaction is validated using xenograft models, as well as distinct Kras- or Braf-driven autochthonous murine cancer models. Lastly, we show that combined checkpoint inhibition induces apoptotic cell death in KRAS- or BRAF-mutant tumor cells directly isolated from patients. These results strongly recommend simultaneous Chk1- and MK2 inhibition as a therapeutic strategy for the treatment of KRAS- or BRAF-driven cancers.
Assuntos
Adenocarcinoma/tratamento farmacológico , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Sinergismo Farmacológico , Inibidores Enzimáticos/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Proto-Oncogênicas/metabolismo , Proteínas ras/metabolismo , Adenocarcinoma/metabolismo , Adenocarcinoma de Pulmão , Animais , Pontos de Checagem do Ciclo Celular , Quinase 1 do Ponto de Checagem , Dano ao DNA , Modelos Animais de Doenças , Xenoenxertos , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Camundongos , Transplante de Neoplasias , Proteínas Proto-Oncogênicas B-raf/metabolismo , Proteínas Proto-Oncogênicas p21(ras) , Células Tumorais CultivadasRESUMO
Broad-spectrum RAS inhibition has the potential to benefit roughly a quarter of human patients with cancer whose tumours are driven by RAS mutations1,2. RMC-7977 is a highly selective inhibitor of the active GTP-bound forms of KRAS, HRAS and NRAS, with affinity for both mutant and wild-type variants3. More than 90% of cases of human pancreatic ductal adenocarcinoma (PDAC) are driven by activating mutations in KRAS4. Here we assessed the therapeutic potential of RMC-7977 in a comprehensive range of PDAC models. We observed broad and pronounced anti-tumour activity across models following direct RAS inhibition at exposures that were well-tolerated in vivo. Pharmacological analyses revealed divergent responses to RMC-7977 in tumour versus normal tissues. Treated tumours exhibited waves of apoptosis along with sustained proliferative arrest, whereas normal tissues underwent only transient decreases in proliferation, with no evidence of apoptosis. In the autochthonous KPC mouse model, RMC-7977 treatment resulted in a profound extension of survival followed by on-treatment relapse. Analysis of relapsed tumours identified Myc copy number gain as a prevalent candidate resistance mechanism, which could be overcome by combinatorial TEAD inhibition in vitro. Together, these data establish a strong preclinical rationale for the use of broad-spectrum RAS-GTP inhibition in the setting of PDAC and identify a promising candidate combination therapeutic regimen to overcome monotherapy resistance.
Assuntos
Antineoplásicos , Carcinoma Ductal Pancreático , Guanosina Trifosfato , Neoplasias Pancreáticas , Proteínas Proto-Oncogênicas p21(ras) , Animais , Feminino , Humanos , Camundongos , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/patologia , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Variações do Número de Cópias de DNA , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Genes myc , Guanosina Trifosfato/metabolismo , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/genética , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/antagonistas & inibidores , Resultado do Tratamento , Ensaios Antitumorais Modelo de Xenoenxerto , MutaçãoRESUMO
Stress response pathways detect and alleviate adverse conditions to safeguard cell and tissue homeostasis, yet their prolonged activation induces apoptosis and disrupts organismal health1-3. How stress responses are turned off at the right time and place remains poorly understood. Here we report a ubiquitin-dependent mechanism that silences the cellular response to mitochondrial protein import stress. Crucial to this process is the silencing factor of the integrated stress response (SIFI), a large E3 ligase complex mutated in ataxia and in early-onset dementia that degrades both unimported mitochondrial precursors and stress response components. By recognizing bifunctional substrate motifs that equally encode protein localization and stability, the SIFI complex turns off a general stress response after a specific stress event has been resolved. Pharmacological stress response silencing sustains cell survival even if stress resolution failed, which underscores the importance of signal termination and provides a roadmap for treating neurodegenerative diseases caused by mitochondrial import defects.
Assuntos
Mitocôndrias , Proteínas Mitocondriais , Mutação , Doenças Neurodegenerativas , Estresse Fisiológico , Ubiquitina-Proteína Ligases , Apoptose/efeitos dos fármacos , Ataxia/genética , Sobrevivência Celular/efeitos dos fármacos , Demência/genética , Mitocôndrias/genética , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Proteínas Mitocondriais/química , Proteínas Mitocondriais/metabolismo , Complexos Multiproteicos/antagonistas & inibidores , Complexos Multiproteicos/genética , Complexos Multiproteicos/metabolismo , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/patologia , Estabilidade Proteica/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Proteólise/efeitos dos fármacos , Estresse Fisiológico/efeitos dos fármacos , Ubiquitina/metabolismo , Ubiquitina-Proteína Ligases/antagonistas & inibidores , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação/efeitos dos fármacosRESUMO
Depending on endoplasmic reticulum (ER) stress levels, the ER transmembrane multidomain protein IRE1α promotes either adaptation or apoptosis. Unfolded ER proteins cause IRE1α lumenal domain homo-oligomerization, inducing trans autophosphorylation that further drives homo-oligomerization of its cytosolic kinase/endoribonuclease (RNase) domains to activate mRNA splicing of adaptive XBP1 transcription factor. However, under high/chronic ER stress, IRE1α surpasses an oligomerization threshold that expands RNase substrate repertoire to many ER-localized mRNAs, leading to apoptosis. To modulate these effects, we developed ATP-competitive IRE1α Kinase-Inhibiting RNase Attenuators-KIRAs-that allosterically inhibit IRE1α's RNase by breaking oligomers. One optimized KIRA, KIRA6, inhibits IRE1α in vivo and promotes cell survival under ER stress. Intravitreally, KIRA6 preserves photoreceptor functional viability in rat models of ER stress-induced retinal degeneration. Systemically, KIRA6 preserves pancreatic ß cells, increases insulin, and reduces hyperglycemia in Akita diabetic mice. Thus, IRE1α powerfully controls cell fate but can itself be controlled with small molecules to reduce cell degeneration.
Assuntos
Estresse do Retículo Endoplasmático , Endorribonucleases/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Regulação Alostérica , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular , Endorribonucleases/química , Endorribonucleases/metabolismo , Ativação Enzimática/efeitos dos fármacos , Humanos , Ilhotas Pancreáticas/metabolismo , Masculino , Camundongos , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/metabolismo , Ratos , Retina/metabolismo , Ribonucleases/antagonistas & inibidoresRESUMO
Because apoptosis of infected cells can limit virus production and spread, some viruses have co-opted prosurvival genes from the host. This includes the Epstein-Barr virus (EBV) gene BHRF1, a homolog of human Bcl-2 proteins that block apoptosis and are associated with cancer. Computational design and experimental optimization were used to generate a novel protein called BINDI that binds BHRF1 with picomolar affinity. BINDI recognizes the hydrophobic cleft of BHRF1 in a manner similar to other Bcl-2 protein interactions but makes many additional contacts to achieve exceptional affinity and specificity. BINDI induces apoptosis in EBV-infected cancer lines, and when delivered with an antibody-targeted intracellular delivery carrier, BINDI suppressed tumor growth and extended survival in a xenograft disease model of EBV-positive human lymphoma. High-specificity-designed proteins that selectively kill target cells may provide an advantage over the toxic compounds used in current generation antibody-drug conjugates.
Assuntos
Herpesvirus Humano 4/química , Engenharia de Proteínas , Proteínas/farmacologia , Proteínas Virais/antagonistas & inibidores , Sequência de Aminoácidos , Animais , Apoptose/efeitos dos fármacos , Biologia Computacional , Cristalografia por Raios X , Infecções por Vírus Epstein-Barr/tratamento farmacológico , Herpesvirus Humano 4/fisiologia , Xenoenxertos , Humanos , Linfoma de Células B/tratamento farmacológico , Camundongos , Modelos Moleculares , Dados de Sequência Molecular , Transplante de Neoplasias , Proteínas/química , Proteínas/metabolismo , Alinhamento de Sequência , Proteínas Virais/químicaRESUMO
Marine-derived cyclic imine toxins, portimine A and portimine B, have attracted attention because of their chemical structure and notable anti-cancer therapeutic potential1-4. However, access to large quantities of these toxins is currently not feasible, and the molecular mechanism underlying their potent activity remains unknown until now. To address this, a scalable and concise synthesis of portimines is presented, which benefits from the logic used in the two-phase terpenoid synthesis5,6 along with other tactics such as exploiting ring-chain tautomerization and skeletal reorganization to minimize protecting group chemistry through self-protection. Notably, this total synthesis enabled a structural reassignment of portimine B and an in-depth functional evaluation of portimine A, revealing that it induces apoptosis selectively in human cancer cell lines with high potency and is efficacious in vivo in tumour-clearance models. Finally, practical access to the portimines and their analogues simplified the development of photoaffinity analogues, which were used in chemical proteomic experiments to identify a primary target of portimine A as the 60S ribosomal export protein NMD3.
Assuntos
Antineoplásicos , Técnicas de Química Sintética , Iminas , Compostos de Espiro , Humanos , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Iminas/síntese química , Iminas/química , Iminas/farmacologia , Neoplasias/tratamento farmacológico , Proteômica , Ribossomos/metabolismo , Proteínas de Ligação a RNA/metabolismo , Compostos de Espiro/síntese química , Compostos de Espiro/química , Compostos de Espiro/farmacologia , Relação Estrutura-Atividade , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologiaRESUMO
Genes that drive the proliferation, survival, invasion and metastasis of malignant cells have been identified for many human cancers1-4. Independent studies have identified cell death pathways that eliminate cells for the good of the organism5,6. The coexistence of cell death pathways with driver mutations suggests that the cancer driver could be rewired to activate cell death using chemical inducers of proximity (CIPs). Here we describe a new class of molecules called transcriptional/epigenetic CIPs (TCIPs) that recruit the endogenous cancer driver, or a downstream transcription factor, to the promoters of cell death genes, thereby activating their expression. We focused on diffuse large B cell lymphoma, in which the transcription factor B cell lymphoma 6 (BCL6) is deregulated7. BCL6 binds to the promoters of cell death genes and epigenetically suppresses their expression8. We produced TCIPs by covalently linking small molecules that bind BCL6 to those that bind to transcriptional activators that contribute to the oncogenic program, such as BRD4. The most potent molecule, TCIP1, increases binding of BRD4 by 50% over genomic BCL6-binding sites to produce transcriptional elongation at pro-apoptotic target genes within 15 min, while reducing binding of BRD4 over enhancers by only 10%, reflecting a gain-of-function mechanism. TCIP1 kills diffuse large B cell lymphoma cell lines, including chemotherapy-resistant, TP53-mutant lines, at EC50 of 1-10 nM in 72 h and exhibits cell-specific and tissue-specific effects, capturing the combinatorial specificity inherent to transcription. The TCIP concept also has therapeutic applications in regulating the expression of genes for regenerative medicine and developmental disorders.