RESUMO
Phosphatidylinositol (PI) is the precursor lipid for the minor phosphoinositides (PPIns), which are critical for multiple functions in all eukaryotic cells. It is poorly understood how phosphatidylinositol, which is synthesized in the ER, reaches those membranes where PPIns are formed. Here, we used VT01454, a recently identified inhibitor of class I PI transfer proteins (PITPs), to unravel their roles in lipid metabolism, and solved the structure of inhibitor-bound PITPNA to gain insight into the mode of inhibition. We found that class I PITPs not only distribute PI for PPIns production in various organelles such as the plasma membrane (PM) and late endosomes/lysosomes, but that their inhibition also significantly reduced the levels of phosphatidylserine, di- and triacylglycerols, and other lipids, and caused prominent increases in phosphatidic acid. While VT01454 did not inhibit Golgi PI4P formation nor reduce resting PM PI(4,5)P2 levels, the recovery of the PM pool of PI(4,5)P2 after receptor-mediated hydrolysis required both class I and class II PITPs. Overall, these studies show that class I PITPs differentially regulate phosphoinositide pools and affect the overall cellular lipid landscape.
Assuntos
Fosfatidilinositóis , Proteínas de Transferência de Fosfolipídeos , Humanos , Fosfatidilinositóis/metabolismo , Proteínas de Transferência de Fosfolipídeos/metabolismo , Proteínas de Transferência de Fosfolipídeos/genética , Metabolismo dos Lipídeos , Membrana Celular/metabolismo , Células HeLa , Organelas/metabolismo , Endossomos/metabolismo , AnimaisRESUMO
The Hippo tumor suppressor pathway controls transcription by regulating nuclear abundance of YAP and TAZ, which activate transcription with the TEAD1-TEAD4 DNA-binding proteins. Recently, several small-molecule inhibitors of YAP and TEADs have been reported, with some entering clinical trials for different cancers with Hippo pathway deregulation, most notably, mesothelioma. Using genome-wide CRISPR/Cas9 screens we reveal that mutations in genes from the Hippo, MAPK, and JAK-STAT signaling pathways all modulate the response of mesothelioma cell lines to TEAD palmitoylation inhibitors. By exploring gene expression programs of mutant cells, we find that MAPK pathway hyperactivation confers resistance to TEAD inhibition by reinstating expression of a subset of YAP/TAZ target genes. Consistent with this, combined inhibition of TEAD and the MAPK kinase MEK, synergistically blocks proliferation of multiple mesothelioma and lung cancer cell lines and more potently reduces the growth of patient-derived lung cancer xenografts in vivo. Collectively, we reveal mechanisms by which cells can overcome small-molecule inhibition of TEAD palmitoylation and potential strategies to enhance the anti-tumor activity of emerging Hippo pathway targeted therapies.
RESUMO
Schwannoma tumours typically arise on the eighth cranial nerve and are mostly caused by loss of the tumour suppressor Merlin (NF2). There are no approved chemotherapies for these tumours and the surgical removal of the tumour carries a high risk of damage to the eighth or other close cranial nerve tissue. New treatments for schwannoma and other NF2-null tumours such as meningioma are urgently required. Using a combination of human primary tumour cells and mouse models of schwannoma, we have examined the role of the Hippo signalling pathway in driving tumour cell growth. Using both genetic ablation of the Hippo effectors YAP and TAZ as well as novel TEAD palmitoylation inhibitors, we show that Hippo signalling may be successfully targeted in vitro and in vivo to both block and, remarkably, regress schwannoma tumour growth. In particular, successful use of TEAD palmitoylation inhibitors in a preclinical mouse model of schwannoma points to their potential future clinical use. We also identify the cancer stem cell marker aldehyde dehydrogenase 1A1 (ALDH1A1) as a Hippo signalling target, driven by the TAZ protein in human and mouse NF2-null schwannoma cells, as well as in NF2-null meningioma cells, and examine the potential future role of this new target in halting schwannoma and meningioma tumour growth.
Assuntos
Neoplasias Meníngeas , Meningioma , Neurilemoma , Animais , Humanos , Camundongos , Proliferação de Células , Neurilemoma/genética , Neurilemoma/patologia , Neurofibromina 2/genética , Neurofibromina 2/metabolismo , Proteínas de Sinalização YAP/metabolismo , Proteínas com Motivo de Ligação a PDZ com Coativador Transcricional/metabolismo , Fatores de Transcrição de Domínio TEA/metabolismoRESUMO
Targeted therapy is effective in many tumor types including lung cancer, the leading cause of cancer mortality. Paradigm defining examples are targeted therapies directed against non-small cell lung cancer (NSCLC) subtypes with oncogenic alterations in EGFR, ALK and KRAS. The success of targeted therapy is limited by drug-tolerant persister cells (DTPs) which withstand and adapt to treatment and comprise the residual disease state that is typical during treatment with clinical targeted therapies. Here, we integrate studies in patient-derived and immunocompetent lung cancer models and clinical specimens obtained from patients on targeted therapy to uncover a focal adhesion kinase (FAK)-YAP signaling axis that promotes residual disease during oncogenic EGFR-, ALK-, and KRAS-targeted therapies. FAK-YAP signaling inhibition combined with the primary targeted therapy suppressed residual drug-tolerant cells and enhanced tumor responses. This study unveils a FAK-YAP signaling module that promotes residual disease in lung cancer and mechanism-based therapeutic strategies to improve tumor response.
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Resistencia a Medicamentos Antineoplásicos , Neoplasias Pulmonares , Transdução de Sinais , Fatores de Transcrição , Proteínas de Sinalização YAP , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Proteínas de Sinalização YAP/metabolismo , Linhagem Celular Tumoral , Animais , Resistencia a Medicamentos Antineoplásicos/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Neoplasia Residual , Camundongos , Quinase 1 de Adesão Focal/metabolismo , Quinase 1 de Adesão Focal/genética , Receptores ErbB/metabolismo , Receptores ErbB/genética , Quinase do Linfoma Anaplásico/metabolismo , Quinase do Linfoma Anaplásico/genética , Quinase do Linfoma Anaplásico/antagonistas & inibidores , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Antineoplásicos/uso terapêutico , Antineoplásicos/farmacologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Primary/intrinsic and treatment-induced acquired resistance limit the initial response rate to and long-term efficacy of direct inhibitors of the KRASG12C mutant in cancer. To identify potential mechanisms of resistance, we applied a CRISPR/Cas9 loss-of-function screen and observed loss of multiple components of the Hippo tumor suppressor pathway, which acts to suppress YAP1/TAZ-regulated gene transcription. YAP1/TAZ activation impaired the antiproliferative and proapoptotic effects of KRASG12C inhibitor (G12Ci) treatment in KRASG12C-mutant cancer cell lines. Conversely, genetic suppression of YAP1/WWTR1 (TAZ) enhanced G12Ci sensitivity. YAP1/TAZ activity overcame KRAS dependency through two distinct TEAD transcription factor-dependent mechanisms, which phenocopy KRAS effector signaling. First, TEAD stimulated ERK-independent transcription of genes normally regulated by ERK (BIRC5, CDC20, ECT2, FOSL1, and MYC) to promote progression through the cell cycle. Second, TEAD caused activation of PI3K-AKT-mTOR signaling to overcome apoptosis. G12Ci treatment-induced acquired resistance was also caused by YAP1/TAZ-TEAD activation. Accordingly, concurrent treatment with pharmacologic inhibitors of TEAD synergistically enhanced KRASG12C inhibitor antitumor activity in vitro and prolonged tumor suppression in vivo. In summary, these observations reveal YAP1/TAZ-TEAD signaling as a crucial driver of primary and acquired resistance to KRAS inhibition and support the use of TEAD inhibitors to enhance the antitumor efficacy of KRAS-targeted therapies. SIGNIFICANCE: YAP1/TAZ-TEAD activation compensates for loss of KRAS effector signaling, establishing a mechanistic basis for concurrent inhibition of TEAD to enhance the efficacy of KRASG12C-selective inhibitor treatment of KRASG12C-mutant cancers. See related commentary by Johnson and Haigis, p. 4005.
Assuntos
Resistencia a Medicamentos Antineoplásicos , Neoplasias , Fatores de Transcrição de Domínio TEA , Humanos , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Transativadores/metabolismo , Proteínas de Sinalização YAP , Fatores de Transcrição de Domínio TEA/antagonistas & inibidoresRESUMO
Non-small lung cancers (NSCLC) frequently (â¼30%) harbor KRAS driver mutations, half of which are KRASG12C. KRAS-mutant NSCLC with comutated STK11 and/or KEAP1 is particularly refractory to conventional, targeted, and immune therapy. Development of KRASG12C inhibitors (G12Ci) provided a major therapeutic advance, but resistance still limits their efficacy. To identify genes whose deletion augments efficacy of the G12Cis adagrasib (MRTX-849) or adagrasib plus TNO155 (SHP2i), we performed genome-wide CRISPR/Cas9 screens on KRAS/STK11-mutant NSCLC lines. Recurrent, potentially targetable, synthetic lethal (SL) genes were identified, including serine-threonine kinases, tRNA-modifying and proteoglycan synthesis enzymes, and YAP/TAZ/TEAD pathway components. Several SL genes were confirmed by siRNA/shRNA experiments, and the YAP/TAZ/TEAD pathway was extensively validated in vitro and in mice. Mechanistic studies showed that G12Ci treatment induced gene expression of RHO paralogs and activators, increased RHOA activation, and evoked ROCK-dependent nuclear translocation of YAP. Mice and patients with acquired G12Ci- or G12Ci/SHP2i-resistant tumors showed strong overlap with SL pathways, arguing for the relevance of the screen results. These findings provide a landscape of potential targets for future combination strategies, some of which can be tested rapidly in the clinic. SIGNIFICANCE: Identification of synthetic lethal genes with KRASG12C using genome-wide CRISPR/Cas9 screening and credentialing of the ability of TEAD inhibition to enhance KRASG12C efficacy provides a roadmap for combination strategies. See related commentary by Johnson and Haigis, p. 4005.
Assuntos
Neoplasias Pulmonares , Proteínas Proto-Oncogênicas p21(ras) , Humanos , Animais , Camundongos , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Fator 2 Relacionado a NF-E2/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , MutaçãoRESUMO
Mutations in the neurofibromatosis type 2 (NF2) gene that limit or abrogate expression of functional Merlin are common in malignant mesothelioma. Merlin activates the Hippo pathway to suppress nuclear translocation of YAP and TAZ, the major effectors of the pathway that associate with the TEAD transcription factors in the nucleus and promote expression of genes involved in cell proliferation and survival. In this article, we describe the discovery of compounds that selectively inhibit YAP/TAZ-TEAD promoted gene transcription, block TEAD auto-palmitoylation, and disrupt interaction between YAP/TAZ and TEAD. Optimization led to potent analogs with excellent oral bioavailability and pharmacokinetics that selectively inhibit NF2-deficient mesothelioma cell proliferation in vitro and growth of subcutaneous tumor xenografts in vivo These highly potent and selective TEAD inhibitors provide a way to target the Hippo-YAP pathway, which thus far has been undruggable and is dysregulated frequently in malignant mesothelioma and in other YAP-driven cancers and diseases.