RESUMO
Metformin has been reported to possess antitumor activity and maintain high cytotoxic T lymphocyte (CTL) immune surveillance. However, the functions and detailed mechanisms of metformin's role in cancer immunity are not fully understood. Here, we show that metformin increases CTL activity by reducing the stability and membrane localization of programmed death ligand-1 (PD-L1). Furthermore, we discover that AMP-activated protein kinase (AMPK) activated by metformin directly phosphorylates S195 of PD-L1. S195 phosphorylation induces abnormal PD-L1 glycosylation, resulting in its ER accumulation and ER-associated protein degradation (ERAD). Consistently, tumor tissues from metformin-treated breast cancer patients exhibit reduced PD-L1 levels with AMPK activation. Blocking the inhibitory signal of PD-L1 by metformin enhances CTL activity against cancer cells. Our findings identify a new regulatory mechanism of PD-L1 expression through the ERAD pathway and suggest that the metformin-CTLA4 blockade combination has the potential to increase the efficacy of immunotherapy.
Assuntos
Antineoplásicos/farmacologia , Antígeno B7-H1/genética , Antígeno CTLA-4/genética , Regulação Neoplásica da Expressão Gênica , Hipoglicemiantes/farmacologia , Metformina/farmacologia , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/imunologia , Animais , Antígeno B7-H1/imunologia , Antígeno CTLA-4/imunologia , Linhagem Celular Tumoral , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/genética , Retículo Endoplasmático/metabolismo , Degradação Associada com o Retículo Endoplasmático , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/imunologia , Feminino , Glicosilação , Humanos , Glândulas Mamárias Humanas/citologia , Glândulas Mamárias Humanas/efeitos dos fármacos , Glândulas Mamárias Humanas/imunologia , Melanoma Experimental/tratamento farmacológico , Melanoma Experimental/genética , Melanoma Experimental/imunologia , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos NOD , Fosforilação , Serina/metabolismo , Linfócitos T Citotóxicos/citologia , Linfócitos T Citotóxicos/efeitos dos fármacos , Linfócitos T Citotóxicos/imunologiaRESUMO
Sustained energy starvation leads to activation of AMP-activated protein kinase (AMPK), which coordinates energy status with numerous cellular processes including metabolism, protein synthesis, and autophagy. Here, we report that AMPK phosphorylates the histone methyltransferase EZH2 at T311 to disrupt the interaction between EZH2 and SUZ12, another core component of the polycomb repressive complex 2 (PRC2), leading to attenuated PRC2-dependent methylation of histone H3 at Lys27. As such, PRC2 target genes, many of which are known tumor suppressors, were upregulated upon T311-EZH2 phosphorylation, which suppressed tumor cell growth both in cell culture and mouse xenografts. Pathologically, immunohistochemical analyses uncovered a positive correlation between AMPK activity and pT311-EZH2, and higher pT311-EZH2 correlates with better survival in both ovarian and breast cancer patients. Our finding suggests that AMPK agonists might be promising sensitizers for EZH2-targeting cancer therapies.
Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Animais , Carcinogênese/genética , Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células , Metilação de DNA , Proteínas de Ligação a DNA/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Proteína Potenciadora do Homólogo 2 de Zeste/fisiologia , Epigênese Genética , Feminino , Histonas/metabolismo , Humanos , Camundongos , Proteínas de Neoplasias , Proteínas Nucleares/metabolismo , Oncogenes , Neoplasias Ovarianas/metabolismo , Fosforilação , Complexo Repressor Polycomb 2/metabolismo , Complexo Repressor Polycomb 2/fisiologia , Fatores de Transcrição , Regulação para CimaRESUMO
Ocimum gratissimum (O. gratissimum), a medicinal herb with antifungal and antiviral activities, has been found to prevent liver injury and liver fibrosis and induce apoptosis in hepatocellular carcinoma (HCC) cells. In this study, we evaluated the effect of aqueous extracts of O. gratissimum (OGE) on improving the efficacy of chemotherapeutic drugs in HCC cells. Proteomic identification and functional assays were used to uncover the critical molecules responsible for OGE-induced sensitization mechanisms. The antitumor activity of OGE in combination with a chemotherapeutic drug was evaluated in a mouse orthotopic tumor model, and serum biochemical tests were further utilized to validate liver function. OGE sensitized HCC cells to the chemotherapeutic drug cisplatin. Proteomic analysis and Western blotting validation revealed the sensitization effect of OGE, likely achieved through the inhibition of breast cancer type 1 susceptibility protein (BRCA1). Mechanically, OGE treatment resulted in BRCA1 protein instability and increased proteasomal degradation, thereby synergistically increasing cisplatin-induced DNA damage. Moreover, OGE effectively inhibited cell migration and invasion, modulated epithelial-to-mesenchymal transition (EMT), and impaired stemness properties in HCC cells. The combinatorial use of OGE enhanced the efficacy of cisplatin and potentially restored liver function in a mouse orthotopic tumor model. Our findings may provide an alternate approach to improving chemotherapy efficacy in HCC.
Assuntos
Proteína BRCA1 , Carcinoma Hepatocelular , Cisplatino , Neoplasias Hepáticas , Ocimum , Extratos Vegetais , Cisplatino/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Animais , Humanos , Ocimum/química , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Camundongos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Proteína BRCA1/metabolismo , Proteína BRCA1/genética , Linhagem Celular Tumoral , Ensaios Antitumorais Modelo de Xenoenxerto , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacosRESUMO
BACKGROUND: The treatment of recurrent or metastatic head and neck squamous-cell carcinoma (R/M HNSCC) remains challenging. Preclinical studies revealed that B cell depletion could modulate the microenvironment and overcome chemoresistance. We conducted a phase I study to evaluate the feasibility and safety of B cell depletion using the anti-CD20 antibody rituximab to treat HNSCC. METHODS: Ten patients were enrolled in two protocols. The first four patients treated using protocol 1 received rituximab 1000 mg on days -14 and -7, followed by gemcitabine/cisplatin every 3 weeks, and rituximab was administered every 6 months thereafter. Because of disease hyperprogression, protocol 1 was amended to protocol 2, which consisted of the concomitant administration of rituximab 375 mg/m2 and gemcitabine/cisplatin every 3 weeks. Another six patients were enrolled and treated using protocol 2. RESULTS: Three patients treated using protocol 1 exhibited rapid disease progression, and the remaining patient could not undergo evaluation after rituximab treatment. Conversely, no unpredicted harm was observed in the six patients treated using protocol 2. Among these patients, one achieved complete response, and two had partial responses. The disease-free durations in these patients were 7.0, 6.2, and 7.1 months, respectively. Immune cell analysis revealed a higher ratio of cytotoxic T cells to regulatory T cells in responders than in non-responders. CONCLUSIONS: B cell depletion using rituximab alone in patients with HNSCC can cause hyperprogressive disease. Contrarily, the co-administration of rituximab and cisplatin/gemcitabine was feasible and safe. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04361409 , 24 April 2020, retrospectively registered.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Cisplatino/administração & dosagem , Desoxicitidina/análogos & derivados , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Rituximab/administração & dosagem , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Adulto , Desoxicitidina/administração & dosagem , Intervalo Livre de Doença , Esquema de Medicação , Estudos de Viabilidade , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/tratamento farmacológico , Projetos Piloto , Resultado do Tratamento , GencitabinaRESUMO
Pluripotency and cell fates can be modulated through the regulation of super-enhancers; however, the underlying mechanisms are unclear. Here, we showed a novel mechanism in which Ash2l directly binds to super-enhancers of several stemness genes to regulate pluripotency and self-renewal in pluripotent stem cells. Ash2l recruits Oct4/Sox2/Nanog (OSN) to form Ash2l/OSN complex at the super-enhancers of Jarid2, Nanog, Sox2 and Oct4, and further drives enhancer activation, upregulation of stemness genes, and maintains the pluripotent circuitry. Ash2l knockdown abrogates the OSN recruitment to all super-enhancers and further hinders the enhancer activation. In addition, CRISPRi/dCas9-mediated blocking of Ash2l-binding motifs at these super-enhancers also prevents OSN recruitment and enhancer activation, validating that Ash2l directly binds to super-enhancers and initiates the pluripotency network. Transfection of Ash2l with W118A mutation to disrupt Ash2l-Oct4 interaction fails to rescue Ash2l-driven enhancer activation and pluripotent gene upregulation in Ash2l-depleted pluripotent stem cells. Together, our data demonstrated Ash2l formed an enhancer-bound Ash2l/OSN complex that can drive enhancer activation, govern pluripotency network and stemness circuitry.
Assuntos
Proteínas de Ligação a DNA/genética , Elementos Facilitadores Genéticos , Células-Tronco Embrionárias Murinas/metabolismo , Fator 3 de Transcrição de Octâmero/genética , Fatores de Transcrição/genética , Animais , Sistemas CRISPR-Cas/genética , Diferenciação Celular/genética , Linhagem da Célula/genética , Autorrenovação Celular/genética , Reprogramação Celular/genética , Elementos Facilitadores Genéticos/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Humanos , Camundongos , Mutação/genética , Proteína Homeobox Nanog/genética , Células-Tronco Pluripotentes/metabolismo , Fatores de Transcrição SOXB1/genética , TransfecçãoRESUMO
Proinflammatory cytokine TNFα plays critical roles in promoting malignant cell proliferation, angiogenesis, and tumor metastasis in many cancers. However, the mechanism of TNFα-mediated tumor development remains unclear. Here, we show that IKKα, an important downstream kinase of TNFα, interacts with and phosphorylates FOXA2 at S107/S111, thereby suppressing FOXA2 transactivation activity and leading to decreased NUMB expression, and further activates the downstream NOTCH pathway and promotes cell proliferation and tumorigenesis. Moreover, we found that levels of IKKα, pFOXA2 (S107/111), and activated NOTCH1 were significantly higher in hepatocellular carcinoma tumors than in normal liver tissues and that pFOXA2 (S107/111) expression was positively correlated with IKKα and activated NOTCH1 expression in tumor tissues. Therefore, dysregulation of NUMB-mediated suppression of NOTCH1 by TNFα/IKKα-associated FOXA2 inhibition likely contributes to inflammation-mediated cancer pathogenesis. Here, we report a TNFα/IKKα/FOXA2/NUMB/NOTCH1 pathway that is critical for inflammation-mediated tumorigenesis and may provide a target for clinical intervention in human cancer.
Assuntos
Carcinoma Hepatocelular/metabolismo , Transformação Celular Neoplásica/metabolismo , Fator 3-beta Nuclear de Hepatócito/genética , Quinase I-kappa B/metabolismo , Neoplasias Hepáticas/metabolismo , Receptor Notch1/metabolismo , Animais , Carcinoma Hepatocelular/patologia , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Fator 3-beta Nuclear de Hepatócito/metabolismo , Humanos , Neoplasias Hepáticas Experimentais/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Modelos Biológicos , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Fosforilação , Receptor Notch1/genética , Transdução de Sinais , Fator de Necrose Tumoral alfa/metabolismoRESUMO
MicroRNAs (miRNAs) are generated by two-step processing to yield small RNAs that negatively regulate target gene expression at the post-transcriptional level. Deregulation of miRNAs has been linked to diverse pathological processes, including cancer. Recent studies have also implicated miRNAs in the regulation of cellular response to a spectrum of stresses, such as hypoxia, which is frequently encountered in the poorly angiogenic core of a solid tumour. However, the upstream regulators of miRNA biogenesis machineries remain obscure, raising the question of how tumour cells efficiently coordinate and impose specificity on miRNA expression and function in response to stresses. Here we show that epidermal growth factor receptor (EGFR), which is the product of a well-characterized oncogene in human cancers, suppresses the maturation of specific tumour-suppressor-like miRNAs in response to hypoxic stress through phosphorylation of argonaute 2 (AGO2) at Tyr 393. The association between EGFR and AGO2 is enhanced by hypoxia, leading to elevated AGO2-Y393 phosphorylation, which in turn reduces the binding of Dicer to AGO2 and inhibits miRNA processing from precursor miRNAs to mature miRNAs. We also identify a long-loop structure in precursor miRNAs as a critical regulatory element in phospho-Y393-AGO2-mediated miRNA maturation. Furthermore, AGO2-Y393 phosphorylation mediates EGFR-enhanced cell survival and invasiveness under hypoxia, and correlates with poorer overall survival in breast cancer patients. Our study reveals a previously unrecognized function of EGFR in miRNA maturation and demonstrates how EGFR is likely to function as a regulator of AGO2 through novel post-translational modification. These findings suggest that modulation of miRNA biogenesis is important for stress response in tumour cells and has potential clinical implications.
Assuntos
Proteínas Argonautas/química , Proteínas Argonautas/metabolismo , Hipóxia Celular/fisiologia , Receptores ErbB/metabolismo , MicroRNAs/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Hipóxia Celular/genética , Linhagem Celular Tumoral , Sobrevivência Celular , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , MicroRNAs/biossíntese , MicroRNAs/química , MicroRNAs/genética , Invasividade Neoplásica , Conformação de Ácido Nucleico , Fosforilação , Fosfotirosina/metabolismo , Prognóstico , Ligação Proteica , Precursores de RNA/química , Precursores de RNA/genética , Precursores de RNA/metabolismo , Ribonuclease III/metabolismo , Análise de SobrevidaRESUMO
Negative-pressure pulmonary edema (NPPE) is acute-onset bilateral pulmonary interstitial edema. This condition can be caused by significant negative intrathoracic pressure generated by large inspiratory effort against acute upper airway obstruction. Postoperative NPPE is rare but potentially life-threatening if not recognized and treated promptly. This article describes a patient who developed postoperative NPPE following a laparoscopic appendectomy.
Assuntos
Apendicectomia , Laringismo/diagnóstico , Complicações Pós-Operatórias/diagnóstico por imagem , Edema Pulmonar/diagnóstico por imagem , Diuréticos/uso terapêutico , Furosemida/uso terapêutico , Humanos , Laparoscopia , Laringismo/complicações , Laringismo/terapia , Masculino , Complicações Pós-Operatórias/tratamento farmacológico , Complicações Pós-Operatórias/etiologia , Edema Pulmonar/tratamento farmacológico , Edema Pulmonar/etiologia , Radiografia Torácica , Adulto JovemRESUMO
(1) Background: A high incidence of intervening sequence (IVS)4+919 G>A mutation with later-onset cardiac phenotype have been reported in a majority of Taiwan Fabry cohorts. Some evidence indicated that conventional biomarkers failed to predict the long-term progression and therapeutic outcome; (2) Methods: In this study, we constructed an induced pluripotent stem cell (iPSC)-based platform from Fabry cardiomyopathy (FC) patients carrying IVS4+919 G>A mutation to screen for potential targets that may help the conventional treatment; (3) Results: The FC-patient-derived iPSC-differentiated cardiomyocytes (FC-iPSC-CMs) carried an expected IVS4+919 G>A genetic mutation and recapitulated several FC characteristics, including low α-galactosidase A enzyme activity and cellular hypertrophy. The proteomic analysis revealed that arachidonate 12/15-lipoxygenase (Alox12/15) was the most highly upregulated marker in FC-iPSC-CMs, and the metabolites of Alox12/15, 12(S)- and 15(S)-hydroxyeicosatetraenoic acid (HETE), were also elevated in the culture media. Late administration of Alox12/15 pharmacological inhibitor LOXBlock-1 combined with α-galactosidase, but not α-galactosidase alone, effectively reduced cardiomyocyte hypertrophy, the secretion of 12(S)- and 15(S)-HETE and the upregulation of fibrotic markers at the late phase of FC; (4) Conclusions: Our study demonstrates that cardiac Alox12/15 and circulating 12(S)-HETE/15(S)-HETE are involved in the pathogenesis of FC with IVS4+919 G>A mutation.
Assuntos
Araquidonato 12-Lipoxigenase/metabolismo , Araquidonato 15-Lipoxigenase/metabolismo , Doença de Fabry/metabolismo , Células-Tronco Pluripotentes Induzidas/citologia , Miócitos Cardíacos/citologia , Miócitos Cardíacos/metabolismo , alfa-Galactosidase/metabolismo , Adulto , Idoso , Reprogramação Celular , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Terapia de Reposição de Enzimas , Doença de Fabry/genética , Feminino , Humanos , Imuno-Histoquímica , Isoenzimas/genética , Isoenzimas/metabolismo , Isoenzimas/uso terapêutico , Masculino , Pessoa de Meia-Idade , Mutação , Proteína Homeobox Nanog/genética , Proteína Homeobox Nanog/metabolismo , Fator 3 de Transcrição de Octâmero/genética , Fator 3 de Transcrição de Octâmero/metabolismo , Fatores de Transcrição SOXB1/genética , Fatores de Transcrição SOXB1/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , alfa-Galactosidase/genética , alfa-Galactosidase/uso terapêuticoRESUMO
Burning incense to worship deities is a popular religious ritual in large parts of Asia, and is a popular custom affecting more than 1.5 billion adherents. Due to incomplete combustion, burning incense has been well recognized to generate airborne hazards to human health. However, the correlation between burning incense and lung cancer in epidemiological studies remains controversy. Therefore, we speculated that some unknown materials in incense smoke are involved in the initiation or progression of lung cancer. Based on this hypothesis, we identified a major compound auramine O (AuO) from the water-soluble fraction of incense burned condensate using mass spectrometry. AuO is commonly used in incense manufacture as a colorant. Due to thermostable, AuO released from burned incenses becomes an unexpected air pollutant. AuO is classified as a Group 2B chemical by the International Agency of Research on Cancer (IARC), however, the damage of AuO to the respiratory system remains elusive. Our study revealed that AuO has no apparent effect on malignant transformation; but, it dramatically promotes lung cancer malignancy. AuO accumulates in the nucleus and induces the autophagy activity in lung tumor cells. AuO significantly enhances migration and invasive abilities and the in vitro and in vivo stemness features of lung tumor cells through activating the expression of aldehyde dehydrogenase family 1 member A1 (ALDH1A1), and ALDH1A1 knockdown attenuates AuO-induced autophagy activity and blocks AuO-induced lung tumor malignancy. In conclusion, we found that AuO, an ingredient of incense smoke, significantly increases the metastatic abilities and stemness characters of lung tumor cells through the activation of ALDH1A1, which is known to be associated with poor outcome and progression of lung cancer. For public health, reducing or avoiding the use of AuO in incense is recommended.
Assuntos
Adenocarcinoma/patologia , Poluentes Atmosféricos/toxicidade , Benzofenoneídio/toxicidade , Corantes/toxicidade , Neoplasias Pulmonares/patologia , Fumaça/efeitos adversos , Adenocarcinoma/induzido quimicamente , Adenocarcinoma de Pulmão , Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados , Aldeído Desidrogenase/genética , Aldeído Desidrogenase/metabolismo , Família Aldeído Desidrogenase 1 , Animais , Linhagem Celular Tumoral , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/patologia , Humanos , Neoplasias Pulmonares/induzido quimicamente , Camundongos Endogâmicos BALB C , Camundongos Nus , Metástase Neoplásica , Mucosa Respiratória/efeitos dos fármacos , Mucosa Respiratória/patologia , Retinal Desidrogenase , Fumaça/análise , Esferoides Celulares/patologiaRESUMO
PARP1 and poly(ADP-ribosyl)ation (PARylation) have been shown to be essential for the initial steps of cellular reprogramming. However, the mechanism underlying PARP1/PARylation-regulated activation of pluripotency loci remains undetermined. Here, we demonstrate that CHD1L, a DNA helicase, possesses chromatin remodeling activity and interacts with PARP1/PARylation in regulating pluripotency during reprogramming. We found that this interaction is mediated through the interplay of the CHD1L macro-domain and the PAR moiety of PARylated-PARP1. Chromatin immunoprecipitation assays demonstrated the co-occupancy of CHD1L and PARP1 at Pou5f1, Nanog, and Esrrb pluripotency loci. Knockdown of CHD1L significantly blocked the binding activity of PARP1 at pluripotency loci and inhibited the efficiency of PARP1-driven reprogramming. Notably, we found that CHD1L-promoted reprogramming requires both a PARP1-interacting domain and DNA helicase activity, partly contributing to the chromatin-remodeling states of pluripotency loci. Taken together, these results identify CHD1L as a key chromatin remodeler involved in PARP1/PARylation-regulated early-stage reprogramming and pluripotency in stem cells.
Assuntos
Reprogramação Celular/genética , Montagem e Desmontagem da Cromatina/genética , DNA Helicases/genética , Proteínas de Ligação a DNA/genética , Células-Tronco Pluripotentes , Poli(ADP-Ribose) Polimerases/genética , Animais , Diferenciação Celular/genética , DNA Helicases/biossíntese , Proteínas de Ligação a DNA/biossíntese , Técnicas de Silenciamento de Genes , Proteínas de Homeodomínio/biossíntese , Camundongos , Proteína Homeobox Nanog , Fator 3 de Transcrição de Octâmero/biossíntese , Poli(ADP-Ribose) Polimerase-1 , Poli(ADP-Ribose) Polimerases/biossíntese , Receptores de Estrogênio/biossínteseRESUMO
BACKGROUND: Paraptosis is a programmed cell death characterized by cytoplasmic vacuolation, which has been explored as an alternative method for cancer treatment and is associated with cancer resistance. However, the mechanisms underlying the progression of paraptosis in cancer cells remain largely unknown. METHODS: Paraptosis-inducing agents, CPYPP, cyclosporin A, and curcumin, were utilized to investigate the underlying mechanism of paraptosis. Next-generation sequencing and liquid chromatography-mass spectrometry analysis revealed significant changes in gene and protein expressions. Pharmacological and genetic approaches were employed to elucidate the transcriptional events related to paraptosis. Xenograft mouse models were employed to evaluate the potential of paraptosis as an anti-cancer strategy. RESULTS: CPYPP, cyclosporin A, and curcumin induced cytoplasmic vacuolization and triggered paraptosis in cancer cells. The paraptotic program involved reactive oxygen species (ROS) provocation and the activation of proteostatic dynamics, leading to transcriptional activation associated with redox homeostasis and proteostasis. Both pharmacological and genetic approaches suggested that cyclin-dependent kinase (CDK) 7/9 drive paraptotic progression in a mutually-dependent manner with heat shock proteins (HSPs). Proteostatic stress, such as accumulated cysteine-thiols, HSPs, ubiquitin-proteasome system, endoplasmic reticulum stress, and unfolded protein response, as well as ROS provocation primarily within the nucleus, enforced CDK7/CDK9-Rpb1 (RNAPII subunit B1) activation by potentiating its interaction with HSPs and protein kinase R in a forward loop, amplifying transcriptional regulation and thereby exacerbating proteotoxicity leading to initiate paraptosis. The xenograft mouse models of MDA-MB-231 breast cancer and docetaxel-resistant OECM-1 head and neck cancer cells further confirmed the induction of paraptosis against tumor growth. CONCLUSIONS: We propose a novel regulatory paradigm in which the activation of CDK7/CDK9-Rpb1 by nuclear proteostatic stress mediates transcriptional regulation to prime cancer cell paraptosis.
RESUMO
The COVID-19 pandemic has caused hundreds million cases and millions death as well as continues to infect human life in the world since late of 2019. The breakthrough infection caused from mutation of SARS-CoV-2 is rising even the vaccinated population has been increasing. Currently, the severe threat posed by SARS-CoV-2 has been alleviated worldwide, and the situation has transitioned to coexisting with the virus. The dietary food with antiviral activities may improve to prevent virus infection for living with COVID-19 pandemic. Teas containing enriched phenolic ingredients such as tannins have been reported to be antitumor agents as well as be good inhibitors for coronavirus. This study developed a highly sensitive and selective ultra-high performance liquid chromatography-high resolution mass spectrometric method for quantification of tannic acids, a hydrolysable tannin, and proanthocyanidins, a condense tannin, in teas with different levels of fermentation. The in vitro pseudoviral particles (Vpp) infection assay was used to evaluate the inhibition activities of various teas. The results of current research demonstrate that the tannins in teas are effective inhibitors against infection of SARS-CoV-2 and its variants.
RESUMO
Chronic inflammation associated with lung cancers contributes to immunosuppressive tumor microenvironments, reducing CD8+ T-cell function and leading to poor patient outcomes. A disintegrin and metalloprotease domain 9 (ADAM9) promotes cancer progression. Here, we aim to elucidate the role of ADAM9 in the immunosuppressive tumor microenvironment. A bioinformatic analysis of TIMER2.0 was used to investigate the correlation of ADAM9 and to infiltrate immune cells in the human lung cancer database and mouse lung tumor samples. Flow cytometry, immunohistochemistry, and RNA sequencing (RNA-seq) were performed to investigate the ADAM9-mediated immunosuppressive microenvironment. The coculture system of lung cancer cells with immune cells, cytokine array assays, and proteomic approach was used to investigate the mechanism. By analyzing the human LUAD database and the mouse lung cancer models, we showed that ADAM9 was associated with the immunosuppressive microenvironment. Additionally, ADAM9 released IL6 protein from cancer cells to inhibit IL12p40 secretion from dendritic cells, therefore leading to dendritic cell dysfunction and further affecting T-cell functions. Proteomic analysis indicated that ADAM9 promoted cholesterol biosynthesis and increased IL6-STAT3 signaling. Mechanistically, ADAM9 reduced the protein stability of LDLR, resulting in reduced cholesterol uptake and induced cholesterol biosynthesis. Moreover, LDLR reduction enhanced IL6-STAT3 activation. We reveal that ADAM9 has a novel biological function that drives the immunosuppressive tumor microenvironment by linking lung cancer's metabolic and signaling axes. Thus, by targeting ADAM9 an innovative and promising therapeutic opportunity was indicated for regulating the immunosuppression of lung cancer.
RESUMO
Bladder cancer poses a significant challenge to chemotherapy due to its resistance to cisplatin, especially at advanced stages. Understanding the mechanisms behind cisplatin resistance is crucial for improving cancer therapy. The enzyme glutathione S-transferase omega class 1 (GSTO1) is known to be involved in cisplatin resistance in colon cancer. This study focused on its role in cisplatin resistance in bladder cancer. Our analysis of protein expression in bladder cancer cells stimulated by secretions from tumor-associated macrophages (TAMs) showed a significant increase in GSTO1. This prompted further investigation into the role of GSTO1 in bladder cancer. We found a strong correlation between GSTO1 expression and cisplatin resistance. Mechanistically, GSTO1 triggered the release of large extracellular vesicles (EVs) that promoted cisplatin efflux, thereby reducing cisplatin-DNA adduct formation and enhancing cisplatin resistance. Inhibition of EV release effectively counteracted the cisplatin resistance associated with GSTO1. In conclusion, GSTO1-mediated EV release may contribute to cisplatin resistance caused by TAMs in bladder cancer. Strategies to target GSTO1 could potentially improve the efficacy of cisplatin in treating bladder cancer.
Assuntos
Cisplatino , Resistencia a Medicamentos Antineoplásicos , Vesículas Extracelulares , Glutationa Transferase , Macrófagos Associados a Tumor , Neoplasias da Bexiga Urinária , Humanos , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Cisplatino/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Vesículas Extracelulares/metabolismo , Glutationa Transferase/metabolismo , Glutationa Transferase/genética , Macrófagos Associados a Tumor/metabolismo , Macrófagos Associados a Tumor/efeitos dos fármacos , Neoplasias da Bexiga Urinária/patologia , Neoplasias da Bexiga Urinária/tratamento farmacológico , Neoplasias da Bexiga Urinária/metabolismo , Neoplasias da Bexiga Urinária/genética , Masculino , Animais , CamundongosRESUMO
Nuclear existence of epidermal growth factor receptor (EGFR) has been documented for more than two decades. Resistance of cancer to radiotherapy is frequently correlated with elevated EGFR expression, activity, and nuclear translocation. However, the role of nuclear EGFR (nEGFR) in radioresistance of cancers remains elusive. In the current study, we identified a novel nEGFR-associated protein, polynucleotide phosphorylase (PNPase), which possesses 3' to 5' exoribonuclease activity toward c-MYC mRNA. Knockdown of PNPase increased radioresistance. Inactivation or knock-down of EGFR enhanced PNPase-mediated c-MYC mRNA degradation in breast cancer cells, and also increased its radiosensitivity. Interestingly, the association of nEGFR with PNPase and DNA-dependent protein kinase (DNAPK) increased significantly in breast cancer cells after exposure to ionizing radiation (IR). We also demonstrated that DNAPK phosphorylates PNPase at Ser-776, which is critical for its ribonuclease activity. The phospho-mimetic S776D mutant of PNPase impaired its ribonuclease activity whereas the nonphosphorylatable S776A mutant effectively degraded c-MYC mRNA. Here, we uncovered a novel role of nEGFR in radioresistance, and that is, upon ionizing radiation, nEGFR inactivates the ribonuclease activity of PNPase toward c-MYC mRNA through DNAPK-mediated Ser-776 phosphorylation, leading to increase of c-MYC mRNA, which contributes to radioresistance of cancer cells.
Assuntos
Proteína Quinase Ativada por DNA/metabolismo , Receptores ErbB/metabolismo , Exorribonucleases/metabolismo , Raios gama , Proteínas Nucleares/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Estabilidade de RNA/efeitos da radiação , RNA Mensageiro/metabolismo , Substituição de Aminoácidos , Linhagem Celular Tumoral , Proteína Quinase Ativada por DNA/genética , Receptores ErbB/genética , Exorribonucleases/genética , Humanos , Mutação de Sentido Incorreto , Proteínas Nucleares/genética , Fosforilação/genética , Fosforilação/efeitos da radiação , Proteínas Proto-Oncogênicas c-myc/genética , Estabilidade de RNA/genética , RNA Mensageiro/genética , Tolerância a Radiação/genética , Tolerância a Radiação/efeitos da radiaçãoRESUMO
EGF induces the translocation of EGF receptor (EGFR) from the cell surface to the nucleus where EGFR activates gene transcription through its binding to an AT-rich sequence (ATRS) of the target gene promoter. However, how EGFR, without a DNA-binding domain, can bind to the gene promoter is unclear. In the present study, we show that RNA helicase A (RHA) is an important mediator for EGFR-induced gene transactivation. EGF stimulates the interaction of EGFR with RHA in the nucleus of cancer cells. The EGFR/RHA complex then associates with the target gene promoter through binding of RHA to the ATRS of the target gene promoter to activate its transcription. Knockdown of RHA expression in cancer cells abrogates the binding of EGFR to the target gene promoter, thereby reducing EGF/EGFR-induced gene expression. In addition, interruption of EGFR-RHA interaction decreases the EGFR-induced promoter activity. Consistently, we observed a positive correlation of the nuclear expression of EGFR, RHA, and cyclin D1 in human breast cancer samples. These results indicate that RHA is a DNA-binding partner for EGFR-mediated transcriptional activation in the nucleus.
Assuntos
Núcleo Celular/metabolismo , DNA/metabolismo , Receptores ErbB/metabolismo , RNA Helicases/metabolismo , Ativação Transcricional , Transporte Ativo do Núcleo Celular , Neoplasias da Mama/metabolismo , Ciclina D1/genética , Ciclina D1/metabolismo , Regulação da Expressão Gênica , Células HeLa , Humanos , Regiões Promotoras Genéticas , Ligação Proteica , RNA Helicases/genéticaRESUMO
Taxanes, particularly docetaxel (DTX), has been widely used for combination therapy of head and neck squamous cell carcinoma (HNSCC). For locally advanced unresectable HNSCC, DTX combined with cisplatin and 5-fluorouracil as a revolutionary treatment revealed an advantage in the improvement of patient outcome. In addition, DTX plus immune check inhibitors (ICIs) showed low toxicity and an increased response of patients with recurrent or metastatic HNSCC (R/M HNSCC). Accumulated data indicate that taxanes not only function as antimitotics but also impair diverse oncogenic signalings, including angiogenesis, inflammatory response, ROS production, and apoptosis induction. However, despite an initial response, the development of resistance remains a major obstacle to treatment response. Taxane resistance could result from intrinsic mechanisms, such as enhanced DNA/RNA damage repair, increased drug efflux, and apoptosis inhibition, and extrinsic effects, such as angiogenesis and interactions between tumor cells and immune cells. This review provides an overview of taxanes therapy applied in different stages of HNSCC and describe the mechanisms of taxane resistance in HNSCC. Through a detailed understanding, the mechanisms of resistance may help in developing the potential therapeutic methods and the effective combination strategies to overcome drug resistance.
RESUMO
Most breast cancers are estrogen receptor (ER)-positive, targeted by endocrine therapies, but chemoresistance remains a significant challenge in treating the disease. Altered intracellular metabolite has closely connected with the pathogenic process of breast cancer and drug resistance. Itaconate is an anti-inflammatory metabolite generated from converting cis-aconitate in the tricarboxylic acid (TCA) cycle by the immune response gene 1 (IRG1). However, the potential role of IRG1/Itaconate in the crosstalk of metabolic pathways and tumor development is currently unknown. We tested the hypothesis that IRG1/Itaconate controls metabolic homeostasis to modulate breast cancer cell growth. We showed that breast cancers harboring an IRG1 deletion displayed a worse prognosis than those without IRG1 deletion; approximately 70% of breast cancer with IRG1 deletion were ER-positive. There was no significant difference in the IRG1 copy number, mRNA, and protein levels between ER-positive and ER-negative breast cancer cell lines and breast tumors. Itaconate selectively inhibited ER-positive breast cancer cell growth via the blockade of DNA synthesis and the induction of apoptosis. Mechanistically, IRG1 overexpression led to decreased intermediate levels of glycolysis, the TCA cycle, and lipid metabolism to compromise the entire biomass and energy of the cell. Itaconate inhibited the enzymatic activity of succinate dehydrogenase (SDH) in the mitochondrial electron-transport chain, concomitant with reactive oxygen species (ROS) production and the decreased adenylate kinase (AK) activities, which, in turn, induced AMP-activated protein kinase (AMPK) activation to restore metabolic homeostasis. These results suggest a new regulatory pathway whereby IRG1/Itaconate controls metabolic homeostasis in ER-positive breast cancer cells, which may contribute to developing more efficacious therapeutic strategies for breast cancer.
RESUMO
BACKGROUND: To date, most countries lifted the restriction requirement and coexisted with SARS-CoV-2. Thus, dietary behavior for preventing SARS-CoV-2 infection becomes an interesting issue on a daily basis. Coffee consumption is connected with reduced COVID-19 risk and correlated to COVID-19 severity. However, the mechanisms of coffee for the reduction of COVID-19 risk are still unclear. RESULTS: Here, we identified that coffee can inhibit multiple variants of the SARS-CoV-2 infection by restraining the binding of the SARS-CoV-2 spike protein to human angiotensin-converting enzyme 2 (ACE2), and reducing transmembrane serine protease 2 (TMPRSS2) and cathepsin L (CTSL) activity. Then, we used the method of "Here" (HRMS-exploring-recombination-examining) and found that isochlorogenic acid A, B, and C of coffee ingredients showed their potential to inhibit SARS-CoV-2 infection (inhibitory efficiency 43-54%). In addition, decaffeinated coffee still preserves inhibitory activity against SARS-CoV-2. Finally, in a human trial of 64 subjects, we identified that coffee consumption (approximately 1-2 cups/day) is sufficient to inhibit infection of multiple variants of SARS-CoV-2 entry, suggesting coffee could be a dietary strategy to prevent SARS-CoV2 infection. CONCLUSIONS: This study verified moderate coffee consumption, including decaffeination, can provide a new guideline for the prevention of SARS-CoV-2. Based on the results, we also suggest a coffee-drinking plan for people to prevent infection in the post-COVID-19 era.