RESUMO
Bromodomain-containing protein 4 (BRD4) has emerged as a promising therapeutic target in prostate cancer (PCa). Understanding the mechanisms of BRD4 stability could enhance the clinical response to BRD4-targeted therapy. In this study, we report that BRD4 protein levels are significantly decreased during mitosis in a PLK1-dependent manner. Mechanistically, we show that BRD4 is primarily phosphorylated at T1186 by the CDK1/cyclin B complex, recruiting PLK1 to phosphorylate BRD4 at S24/S1100, which are recognized by the APC/CCdh1 complex for proteasome pathway degradation. We find that PLK1 overexpression lowers SPOP mutation-stabilized BRD4, consequently rendering PCa cells re-sensitized to BRD4 inhibitors. Intriguingly, we report that sequential treatment of docetaxel and JQ1 resulted in significant inhibition of PCa. Collectively, the results support that PLK1-phosphorylated BRD4 triggers its degradation at M phase. Sequential treatment of docetaxel and JQ1 overcomes BRD4 accumulation-associated bromodomain and extra-terminal inhibitor (BETi) resistance, which may shed light on the development of strategies to treat PCa.
Assuntos
Azepinas , Proteínas de Ciclo Celular , Docetaxel , Resistencia a Medicamentos Antineoplásicos , Mitose , Quinase 1 Polo-Like , Neoplasias da Próstata , Proteínas Serina-Treonina Quinases , Proteínas Proto-Oncogênicas , Fatores de Transcrição , Triazóis , Humanos , Proteínas de Ciclo Celular/metabolismo , Masculino , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/genética , Fosforilação , Proteínas Proto-Oncogênicas/metabolismo , Mitose/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/metabolismo , Fatores de Transcrição/metabolismo , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Linhagem Celular Tumoral , Azepinas/farmacologia , Triazóis/farmacologia , Docetaxel/farmacologia , Proteólise/efeitos dos fármacos , Proteínas Nucleares/metabolismo , Animais , Proteína Quinase CDC2/metabolismo , Camundongos Nus , Camundongos , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas que Contêm Bromodomínio , Proteínas RepressorasRESUMO
PLK1 (Polo-like kinase 1) plays a critical role in the progression of lung adenocarcinoma (LUAD). Recent studies have unveiled that targeting PLK1 improves the efficacy of immunotherapy, highlighting its important role in the regulation of tumor immunity. Nevertheless, our understanding of the intricate interplay between PLK1 and the tumor microenvironment (TME) remains incomplete. Here, using genetically engineered mouse model and single-cell RNA-seq analysis, we report that PLK1 promotes an immunosuppressive TME in LUAD, characterized with enhanced M2 polarization of tumor associated macrophages (TAM) and dampened antigen presentation process. Mechanistically, elevated PLK1 coincides with increased secretion of CXCL2 cytokine, which promotes M2 polarization of TAM and diminishes expression of class II major histocompatibility complex (MHC-II) in professional antigen-presenting cells. Furthermore, PLK1 negatively regulates MHC-II expression in cancer cells, which has been shown to be associated with compromised tumor immunity and unfavorable patient outcomes. Taken together, our results reveal PLK1 as a novel modulator of TME in LUAD and provide possible therapeutic interventions.
Assuntos
Adenocarcinoma de Pulmão , Proteínas de Ciclo Celular , Neoplasias Pulmonares , Quinase 1 Polo-Like , Proteínas Serina-Treonina Quinases , Proteínas Proto-Oncogênicas , Análise de Célula Única , Microambiente Tumoral , Animais , Humanos , Camundongos , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/imunologia , Adenocarcinoma de Pulmão/patologia , Apresentação de Antígeno/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Quimiocina CXCL2/genética , Quimiocina CXCL2/metabolismo , Regulação Neoplásica da Expressão Gênica , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe II/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/patologia , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Microambiente Tumoral/imunologia , Microambiente Tumoral/genética , Macrófagos Associados a Tumor/imunologia , Macrófagos Associados a Tumor/metabolismoRESUMO
Metastasis of lung adenocarcinoma (LUAD) is a major cause of death in patients. Aryl hydrocarbon receptor (AHR), an important transcription factor, is involved in the initiation and progression of lung cancer. Polo-like kinase 1 (PLK1), a serine/threonine kinase, acts as an oncogene promoting the malignancy of multiple cancer types. However, the interaction between these two factors and their significance in lung cancer remain to be determined. In this study, we demonstrate that PLK1 phosphorylates AHR at S489 in LUAD, leading to epithelial-mesenchymal transition (EMT) and metastatic events. RNA-seq analyses reveal that type 2 deiodinase (DIO2) is responsible for EMT and enhanced metastatic potential. DIO2 converts tetraiodothyronine (T4) to triiodothyronine (T3), activating thyroid hormone (TH) signaling. In vitro and in vivo experiments demonstrate that treatment with T3 or T4 promotes the metastasis of LUAD, whereas depletion of DIO2 or a deiodinase inhibitor disrupts this property. Taking together, our results identify the AHR phosphorylation by PLK1 and subsequent activation of DIO2-TH signaling as mechanisms leading to LUAD metastasis. These findings can inform possible therapeutic interventions for this event.
Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Humanos , Fosforilação , Iodeto Peroxidase/metabolismo , Receptores de Hidrocarboneto Arílico/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Adenocarcinoma de Pulmão/genética , Hormônios Tireóideos/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Transição Epitelial-Mesenquimal/genética , Proliferação de Células/fisiologia , Quinase 1 Polo-LikeRESUMO
PLK1 (Polo-like kinase 1) plays a critical role in the progression of lung adenocarcinoma (LUAD). Recent studies have unveiled that targeting PLK1 improves the efficacy of immunotherapy, highlighting its important role in the regulation of tumor immunity. Nevertheless, our understanding of the intricate interplay between PLK1 and the tumor microenvironment (TME) remains incomplete. Here, using genetically engineered mouse model and single-cell RNA-seq analysis, we report that PLK1 promotes an immunosuppressive TME in LUAD, characterized with enhanced M2 polarization of tumor associated macrophages (TAM) and dampened antigen presentation process. Mechanistically, elevated PLK1 coincides with increased secretion of CXCL2 cytokine, which promotes M2 polarization of TAM and diminishes expression of class II major histocompatibility complex (MHC-II) in professional antigen-presenting cells. Furthermore, PLK1 negatively regulates MHC-II expression in cancer cells, which has been shown to be associated with compromised tumor immunity and unfavorable patient outcomes. Taken together, our results reveal PLK1 as a novel modulator of TME in LUAD and provide possible therapeutic interventions.
RESUMO
Metastasis of Lung adenocarcinoma (LUAD) is a major cause of death in patients. Aryl hydrocarbon receptor (AHR) is an important transcription factor involved in the initiation and progression of lung cancer. Polo-like kinase 1 (PLK1), a serine/threonine kinase, is an oncogene that promotes the malignancy of multiple cancer types. Nonetheless, the interaction between these two factors and significance in lung cancer remains to be determined. Here, we demonstrate that PLK1 phosphorylates AHR at S489 in LUAD, which leads to epithelial-mesenchymal transition (EMT) and metastatic events. RNA-seq analyses show that type 2 deiodinase (DIO2) is responsible for EMT and enhanced metastatic potential. DIO2 converts tetraiodothyronine (T4) to triiodothyronine (T3), which then activates thyroid hormone signaling. In vitro and in vivo experiments demonstrate that treatment with T3 or T4 promotes the metastasis of LUAD, whereas depletion of DIO2 or deiodinase inhibitor disrupts this property. Taken together, our results identify the phosphorylation of AHR by PLK1 as a mechanism leading to the progression of LUAD and provide possible therapeutic interventions for this event.
RESUMO
Enzalutamide (ENZA), a second-generation androgen receptor antagonist, has significantly increased progression-free and overall survival of patients with metastatic prostate cancer (PCa). However, resistance remains a prominent obstacle in treatment. Utilizing a kinome-wide CRISPR-Cas9 knockout screen, we identified casein kinase 1α (CK1α) as a therapeutic target to overcome ENZA resistance. Depletion or pharmacologic inhibition of CK1α enhanced ENZA efficacy in ENZA-resistant cells and patient-derived xenografts. Mechanistically, CK1α phosphorylates the serine residue S1270 and modulates the protein abundance of ataxia telangiectasia mutated (ATM), a primary initiator of DNA double-strand break (DSB)-response signaling, which is compromised in ENZA-resistant cells and patients. Inhibition of CK1α stabilizes ATM, resulting in the restoration of DSB signaling, and thus increases ENZA-induced cell death and growth arrest. Our study details a therapeutic approach for ENZA-resistant PCa and characterizes a particular perspective for the function of CK1α in the regulation of DNA-damage response.
Assuntos
Caseína Quinase Ialfa , Neoplasias de Próstata Resistentes à Castração , Masculino , Humanos , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/patologia , Feniltioidantoína/farmacologia , Feniltioidantoína/uso terapêutico , DNA/uso terapêuticoRESUMO
Increased abundance of polo-like kinase 1 (PLK1) is observed in various tumor types, particularly in lung adenocarcinoma (LUAD). Here, we found that PLK1 accelerated the progression of LUAD through a mechanism that was independent of its role in mediating mitotic cell division. Analysis of human tumor databases revealed that increased PLK1 abundance in LUAD correlated with mutations in KRAS and p53, with tumor stage, and with reduced survival in patients. In a mouse model of KRASG12D-driven, p53-deficient LUAD, PLK1 overexpression increased tumor burden, decreased tumor cell differentiation, and reduced animal survival. PLK1 overexpression in cultured cells and mice indirectly increased the expression of the gene encoding the receptor tyrosine kinase RET by phosphorylating the transcription factor TTF-1. Signaling by RET and mutant KRAS in these tumors converged to activate the mitogen-activated protein kinase (MAPK) pathway. Pharmacological inhibition of the MAPK pathway kinase MEK combined with inhibition of either RET or PLK1 markedly suppressed tumor growth. Our findings show that PLK1 can amplify MAPK signaling and reveal a potential target for stemming progression in lung cancers with high PLK1 abundance.
Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Adenocarcinoma de Pulmão/genética , Animais , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Humanos , Neoplasias Pulmonares/metabolismo , Camundongos , Quinases de Proteína Quinase Ativadas por Mitógeno/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Proteínas Serina-Treonina Quinases , Proteínas Proto-Oncogênicas , Proteínas Proto-Oncogênicas c-ret/genética , Proteínas Proto-Oncogênicas c-ret/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Fatores de Transcrição/metabolismo , Ativação Transcricional , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Quinase 1 Polo-LikeRESUMO
Prostate cancer (PCa) continues to threaten men's health, and treatment targeting the androgen receptor (AR) pathway is the major therapy for PCa patients. Several second-generation androgen receptor inhibitors (SG-ARIs), including enzalutamide (ENZ), apalutamide (APA) and darolutamide (DARO), have been developed to better block the activity of AR. Unavoidably, emergence of resistance to these novel drugs still persists. Herein, we identified glutathione S-transferase Mu 2 (GSTM2) as an important determinant in the acquisition of resistance to SG-ARIs. Elevated GSTM2 was detected in enzalutamide-resistant (ENZ-R) PCa, and overexpression of GSTM2 in naïve enzalutamide-sensitive (ENZ-S) cells effectively transformed them to ENZ-R PCa. Aryl hydrocarbon receptor (AhR), the upstream transcription factor, was implicated in the overexpression of GSTM2 in ENZ-R cells. Mechanistically, GSTM2 antagonized the effect of ENZ by rescuing cells from oxidative stress-associated damage and activation of p38 MAPK pathway. Surprisingly, high GSTM2 levels also associated with cross-resistance to APA and DARO. Taking together, these results provide new insight to ameliorate resistance to SG-ARIs and improve treatment outcome.
Assuntos
Antagonistas de Receptores de Andrógenos , Resistencia a Medicamentos Antineoplásicos , Glutationa Transferase , Neoplasias de Próstata Resistentes à Castração , Antagonistas de Receptores de Andrógenos/farmacologia , Benzamidas , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/genética , Glutationa Transferase/genética , Humanos , Masculino , Nitrilas/farmacologia , Feniltioidantoína , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/metabolismo , Receptores Androgênicos/metabolismo , Receptores de Hidrocarboneto Arílico , Proteínas Quinases p38 Ativadas por MitógenoRESUMO
BACKGROUND: The androgen receptor (AR) signaling pathway has been well demonstrated to play a crucial role in the development, progression, and drug resistance of prostate cancer. Although the current anti-androgen therapy could significantly benefit prostate cancer patients initially, the efficacy of the single drug usually lasts for a relatively short period, as drug resistance quickly emerges. METHODS: We have performed an unbiased bioinformatics analysis using the RNA-seq results in 22Rv1 cells to identify the cell response toward Dip G treatment. The RNA-seq results were validated by qRT-PCR. Protein levels were detected by western blot or staining. Cell viability was measured by Aquabluer and colony formation assay. RESULTS: Here, we identified that Diptoindonesin G (Dip G), a natural extracted compound, could promote the proteasome degradation of AR and polo-like kinase 1 (PLK1) through modulating the activation of CHIP E3 ligase. Administration of Dip G has shown a profound efficiency in the suppression of AR and PLK1, not only in androgen-dependent LNCaP cells but also in castration-resistant and enzalutamide-resistant cells in a CHIP-dependent manner. Through co-targeting the AR signaling, Dip G robustly improved the efficacy of HSP90 inhibitors and enzalutamide in both human prostate cancer cells and in vivo xenograft mouse model. CONCLUSIONS: Our results revealed that Dip G-mediated AR degradation would be a promising and valuable therapeutic strategy in the clinic.
Assuntos
Neoplasias de Próstata Resistentes à Castração , Antagonistas de Androgênios/farmacologia , Antagonistas de Androgênios/uso terapêutico , Animais , Benzofuranos , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Humanos , Masculino , Camundongos , Nitrilas/uso terapêutico , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/metabolismo , Receptores Androgênicos/metabolismo , Transdução de Sinais , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Background: Osteosarcoma is a common malignant bone tumor with a poor prognosis. The progression and metastasis of osteosarcoma are significantly influenced by the tumor microenvironment (TME). This study aimed to develop a personalized classifier based on metastasis and immune cells in the TME to achieve better prognostic prediction in osteosarcoma. Methods: Firstly, osteosarcoma metastasis-related differentially expressed genes (DEGs) and infiltrating immune cells in the TME were analyzed using a series of bioinformatics methods. The metastasis-related gene signature (MRS) and TME score of osteosarcoma patients were then developed. On this basis, a personalized MRS-TME classifier was constructed and validated in other clinical cohorts and different subgroups. In addition, the relationship between the MRS-related genes and the immune microenvironment was also clarified. Finally, the signaling pathways and immune response genes in osteosarcoma patients among different MRS-TME subgroups were analyzed to explore the underlying molecular mechanism. Results: We first identified the metastasis-related DEGs in osteosarcoma, which were primarily involved in the muscle system process, calcium ion homeostasis, cell chemotaxis, and leukocyte migration. A personalized MRS-TME classifier was then constructed by integrating the MRS (10 genes) and TME (six immune cells) scores. The MRS-TME classifier demonstrated a potent capacity of predicting the survival prognosis in diverse osteosarcoma cohorts as well as in the clinical feature subgroups. The MRS score was negatively associated with the TME score, and patients in the MRSlow/TMEhigh subgroup exhibited a better prognosis compared to all other subgroups. Significant differences existed between the cellular signaling pathways and immune response profiles among the different MRS-TME subgroups, especially in relation to the metabolism-related biological processes and the inflammatory response. Conclusions: The MRS-TME classifier might be a beneficial tool to aid in the prognostic evaluation and risk stratification of osteosarcoma patients.
RESUMO
CONTEXT: The immune system plays a central role in the pathophysiology of gestational diabetes mellitus (GDM). Monocytes, the main innate immune cells, are especially important in the maintenance of a normal pregnancy. OBJECTIVE: Here, we investigated the potential effect of monocytes in GDM. METHODS: Monocyte count was monitored throughout pregnancy in 214 women with GDM and 926 women without in a case-control and cohort study. Circulating levels of inflammatory cytokines, placenta-derived macrophages, and their products were measured. RESULTS: Throughout pregnancy, monocyte count was significantly decreased in women with GDM, and was closely associated with glucose level, insulin resistance, and newborn weight. First-trimester monocyte count outperformed that of the second and third trimester as a risk factor and diagnostic predictor of GDM and macrosomia both in the case-control and cohort study. In addition, our cohort study showed that as first-trimester monocyte count decreased, GDM and macrosomia incidence, glucose level, and newborn weight increased in a stepwise manner. Risk of GDM started to decrease rapidly when first-trimester monocyte count exceeded 0.48â ×â 109/L. Notably, CD206 and interleukin 10 (IL-10) were significantly lower, whereas CD80, CD86, tumor necrosis factor α (TNF-α), and interleukin 6 (IL-6) were higher both in GDM placental tissue and peripheral blood. First-trimester monocyte count was positively related to IL-10 and CD206, but negatively related to CD80, CD86, TNF-α, and IL-6. CONCLUSION: Decreased monocyte count throughout pregnancy was closely associated with the development of GDM, macrosomia, and the chronic inflammatory state of GDM. First-trimester monocyte count has great potential as an early diagnostic marker of GDM.
Assuntos
Diabetes Gestacional/epidemiologia , Macrossomia Fetal/epidemiologia , Monócitos/imunologia , Adulto , Peso ao Nascer/imunologia , Glicemia/análise , Estudos de Casos e Controles , Diabetes Gestacional/sangue , Diabetes Gestacional/diagnóstico , Diabetes Gestacional/imunologia , Feminino , Macrossomia Fetal/imunologia , Humanos , Incidência , Recém-Nascido , Inflamação/sangue , Inflamação/epidemiologia , Inflamação/imunologia , Contagem de Leucócitos , Gravidez , Primeiro Trimestre da Gravidez/sangue , Medição de Risco/métodos , Fatores de Risco , Adulto JovemRESUMO
Ribosome biogenesis plays a pivotal role in tumorigenesis by supporting robust protein translation. We investigate the functional and molecular mechanism of Zinc finger protein 545 (ZNF545), a transcriptional repressor for ribosomal RNA (rRNA), in colorectal cancer (CRC). ZNF545 was silenced in CRC compared to adjacent normal tissues (P < 0.0001), implying a tumor-suppressive role. Colon-specific Znf545 knockout in mice accelerated CRC in ApcMin/+ and azoxymethane/dextran sulfate sodium-induced CRC. Mechanistically, we demonstrated that ZNF545 uses its two zinc finger clusters to bind to minimal rDNA promoter, where it assembled transcriptional repressor complex by interacting with KAP1. Znf545 deletion in mouse embryonic fibroblasts not only increased rRNA transcription rate and the nucleolar size and number but also altered the nucleolar composition and architecture with an increased number of fibrillar centers surrounded by net-like dense fibrillar components. Consequently, Znf545 deletion promoted the gene expression of translation machinery, protein translation, and cell growth. Consistent with its tumor-suppressive role, ZNF545 overexpression in CRC cells induced growth arrest and apoptosis. Finally, administration of rRNA synthesis inhibitor, CX-5461, inhibited CRC development in Znf545Δ/ΔApcMin/+ mice. In conclusion, ZNF545 suppresses CRC through repressing rRNA transcription and protein translation. Targeting rRNA biosynthesis in ZNF545-silenced tumors is a potential therapeutic strategy for CRC.
Assuntos
Carcinogênese/patologia , Neoplasias Colorretais/patologia , Proteínas Nucleares/fisiologia , Biossíntese de Proteínas , RNA Ribossômico/metabolismo , Ribossomos/metabolismo , Animais , Azoximetano/toxicidade , Carcinogênese/genética , Carcinogênese/metabolismo , Comunicação Celular , Nucléolo Celular/genética , Nucléolo Celular/metabolismo , Proliferação de Células , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Fibroblastos/metabolismo , Fibroblastos/patologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , RNA Ribossômico/genéticaRESUMO
Prostate cancer (PCa) is the most commonly diagnosed malignancy among men, and the progression of this disease results in fewer treatment options available to clinical patients. It highlights the vital necessity for discovering novel therapeutic approaches and expanding the current understanding of molecular mechanisms. Epigenetic alternations such as DNA methylation models and histone modifications have been associated as key drivers in the development and advancement of PCa. Several studies have been conducted and demonstrated that targeting these epigenetic enzymes or regulatory proteins has been strongly associated with the regulation of cancer cell growth. Due to the success rate of these therapeutic routes in pre-clinical settings, many drugs have now advanced to clinical testing, where efficacy will be measured. This review will discuss the role of epigenetic modifications in PCa development and its function in the progression of the disease to resistant forms and introduce therapeutic strategies that have demonstrated successful results as PCa treatment.
RESUMO
Upregulation of EZH2 is associated with advanced stage and poor prognosis of prostate cancer; therefore, it is likely to be a promising therapeutic target. Metformin, a drug that has been used to treat type 2 diabetes, was found to have antineoplastic activity in different cancers. Herein, we report that the combination of metformin and the EZH2 inhibitor GSK126 exerts synergistic inhibition on prostate cancer cell growth, both in vitro and in vivo Mechanistically, we identify that metformin can reduce EZH2 expression through upregulating miR-26a-5p, which is antagonized by androgen receptor (AR). Furthermore, we show that AR binds to the promoter of miR-26a-5p and suppresses its transcription. Although metformin can remove AR from the miR-26a-5p promoter, the interaction between AR and EZH2, which usually exists in androgen-refractory prostate cancer cells, strongly impedes the removal. However, GSK126 can inhibit the methyltransferase-dependent interaction between AR and EZH2, thus restoring metformin's efficacy in androgen-refractory prostate cancer cells. Collectively, our finding suggests that the combination of metformin and GSK126 would be an effective approach for future prostate cancer therapy, and particularly effective for AR-positive castration-resistant prostate cancer.
Assuntos
Antineoplásicos/farmacologia , Proteína Potenciadora do Homólogo 2 de Zeste/antagonistas & inibidores , Metformina/farmacologia , Neoplasias da Próstata/metabolismo , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Sinergismo Farmacológico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Indóis/farmacologia , Masculino , Camundongos , MicroRNAs/genética , Regiões Promotoras Genéticas , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/etiologia , Neoplasias da Próstata/patologia , Piridonas/farmacologia , Receptores Androgênicos/metabolismo , Ativação Transcricional , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Prostate cancer (PCa) cells heavily rely on an active androgen receptor (AR) pathway for their survival. Enzalutamide (MDV3100) is a second-generation antiandrogenic drug that was approved by the Food and Drug Administration in 2012 to treat patients with castration-resistant prostate cancer (CRPC). However, emergence of resistance against this drug is inevitable, and it has been a major challenge to develop interventions that help manage enzalutamide-resistant CRPC. Erythropoietin-producing human hepatocellular (Eph) receptors are targeted by ephrin protein ligands and have a broad range of functions. Increasing evidence indicates that this signaling pathway plays an important role in tumorigenesis. Overexpression of EPH receptor B4 (EPHB4) has been observed in multiple types of cancer, being closely associated with proliferation, invasion, and metastasis of tumors. Here, using RNA-Seq analyses of clinical and preclinical samples, along with several biochemical and molecular methods, we report that enzalutamide-resistant PCa requires an active EPHB4 pathway that supports drug resistance of this tumor type. Using a small kinase inhibitor and RNAi-based gene silencing to disrupt EPHB4 activity, we found that these disruptions re-sensitize enzalutamide-resistant PCa to the drug both in vitro and in vivo Mechanistically, we found that EPHB4 stimulates the AR by inducing proto-oncogene c-Myc (c-Myc) expression. Taken together, these results provide critical insight into the mechanism of enzalutamide resistance in PCa, potentially offering a therapeutic avenue for enhancing the efficacy of enzalutamide to better manage this common malignancy.
Assuntos
Resistencia a Medicamentos Antineoplásicos , Neoplasias de Próstata Resistentes à Castração/metabolismo , Receptor EphB4/metabolismo , Receptores Androgênicos/genética , Animais , Antineoplásicos/uso terapêutico , Benzamidas , Linhagem Celular Tumoral , Humanos , Masculino , Camundongos , Camundongos Nus , Nitrilas , Feniltioidantoína/análogos & derivados , Feniltioidantoína/uso terapêutico , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas c-myc/metabolismo , Receptor EphB4/antagonistas & inibidores , Receptores Androgênicos/metabolismoRESUMO
BACKGROUND: Chromosomal instability plays an important part in cancer, but its genetic basis in liver tumorigenesis remains largely unclear. We aimed to characterize the mechanistic significance and clinical implication of mitotic regulator microtubule-associated protein 9 (MAP9) in hepatocellular carcinoma (HCC). METHODS: The biological functions of MAP9 were determined by in vitro tumorigenicity assays. Systematic MAP9 knockout mouse (MAP9∆/∆) and hepatocyte-specific MAP9 knockout mouse (MAP9∆/∆hep) were generated to confirm the role of MAP9 in HCC. The clinical impact of MAP9 was assessed in primary HCC tissue samples. FINDINGS: We found that MAP9 was frequently silenced in HCC tissue samples. The transcriptional silence of MAP9 in liver cancer cell lines and tissue samples was mediated by its promoter hypermethylation. MAP9 promoter hypermethylation or downregulation was associated with poor survival and recurrence in patients with HCC. Mechanistically, ectopic expression of MAP9 in LO2 and HepG2 cell lines impaired cell proliferation, colony formation, migration and invasion, and induced cell apoptosis and cycle arrest, whereas knockdown of MAP9 in Miha cell line showed the opposite effects. We found that MAP9∆/∆ mice spontaneously developed a liver hyperplastic nodule and MAP9∆/∆hep accelerated diethylnitrosamine-induced HCC formation. The tumour suppressive effect of MAP9 in HCC was mediated by downregulating excision repair cross-complementation group 3 (ERCC3), a nucleotide excision repair gene. Restoration of ERCC3 expression possessed an oncogenic potency and abrogated the tumour suppressive effects of MAP9. INTERPRETATION: MAP9 is a novel tumour suppressor in HCC by inhibiting ERCC3 expression, and serves as a prognostic factor in HCC patients.
Assuntos
Biomarcadores Tumorais/genética , Carcinogênese/genética , Carcinoma Hepatocelular/metabolismo , DNA Helicases/genética , Proteínas de Ligação a DNA/genética , Neoplasias Hepáticas/metabolismo , Proteínas Associadas aos Microtúbulos/genética , Animais , Biomarcadores Tumorais/metabolismo , Carcinogênese/metabolismo , Carcinogênese/patologia , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Movimento Celular , Proliferação de Células , DNA Helicases/metabolismo , Proteínas de Ligação a DNA/metabolismo , Regulação para Baixo , Inativação Gênica , Células Hep G2 , Hepatócitos/metabolismo , Hepatócitos/fisiologia , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Associadas aos Microtúbulos/metabolismo , Células Tumorais CultivadasRESUMO
Blockade of programmed death-ligand 1 (PD-L1) by therapeutic antibodies has shown to be a promising strategy in cancer therapy, yet clinical response in many types of cancer, including prostate cancer (PCa), is limited. Tumor cells secrete PD-L1 through exosomes or splice variants, which has been described as a new mechanism for the resistance to PD-L1 blockade therapy in multiple cancers, including PCa. This suggests that cutting off the secretion or expression of PD-L1 might improve the response rate of PD-L1 blockade therapy in PCa treatment. Here we report that p300/CBP inhibition by a small molecule p300/CBP inhibitor dramatically enhanced the efficacy of PD-L1 blockade treatment in a syngeneic model of PCa by blocking both the intrinsic and IFN-γ-induced PD-L1 expression. Mechanistically, p300/CBP could be recruited to the promoter of CD274 (encoding PD-L1) by the transcription factor IRF-1, which induced the acetylation of Histone H3 at CD274 promoter followed by the transcription of CD274. A485, a p300/CBP inhibitor, abrogated this process and cut off the secretion of exosomal PD-L1 by blocking the transcription of CD274, which combined with the anti-PD-L1 antibody to reactivate T cells function for tumor attack. This finding reports a new mechanism of how cancer cells regulate PD-L1 expression through epigenetic factors and provides a novel therapeutic approach to enhance the efficacy of immune checkpoint inhibitors treatment.
Assuntos
Antígeno B7-H1/genética , Interferon gama/genética , Neoplasias da Próstata/terapia , Bibliotecas de Moléculas Pequenas/farmacologia , Fatores de Transcrição de p300-CBP/genética , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/farmacologia , Antígeno B7-H1/antagonistas & inibidores , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Imunoterapia/métodos , Fator Regulador 1 de Interferon/genética , Masculino , Neoplasias da Próstata/genética , Neoplasias da Próstata/imunologia , Neoplasias da Próstata/patologia , Linfócitos T/imunologia , Fatores de Transcrição de p300-CBP/antagonistas & inibidoresRESUMO
PURPOSE: Chromosomal instability (CIN) is a common phenomenon in colorectal cancer, but its role and underlying cause remain unknown. We have identified that mitotic regulator microtubule-associated protein 9 (MAP9) is a critical regulator of CIN in colorectal cancer. We thus studied the effect of MAP9 loss on colorectal cancer in Map9-knockout mice and in cell lines. EXPERIMENTAL DESIGN: We generated colon epithelial-specific Map9-knockout mice and evaluated colorectal cancer development. Effect of Map9 knockout on colorectal cancer progression was determined in chemical or ApcMin /+ -induced colorectal cancer. Molecular mechanism of MAP9 was determined using spectral karyotyping, microtubule assays, and whole-genome sequencing (WGS). Clinical significance of MAP9 was examined in 141 patients with CRC. RESULTS: Spontaneous colonic tumors (9.1%) were developed in colon epithelium-specific Map9-knockout mice at 17 months, but none was observed in wild-type littermates. Map9 deletion accelerated colorectal cancer formation both in ApcMin /+ mice and azoxymethane-treated mice, and reduced survival in ApcMin /+ mice. Mechanistically, MAP9 stabilized microtubules and mediated mitotic spindle assembly. MAP9 also maintained the spindle pole integrity and protected K-fiber from depolymerization at spindle poles. MAP9 loss induced severe mitosis failure, chromosome segregation errors, and aneuploidy, leading to transformation of normal colon epithelial cells. WGS confirmed enhanced CIN in intestinal tumors from Map9 knockout ApcMin /+ mice. In patients with colorectal cancer, MAP9 was frequently silenced and its downregulation was associated with poor survival. CONCLUSIONS: MAP9 is a microtubule stabilizer that contributes to spindle stability and inhibits colorectal tumorigenesis, supporting the role of MAP9 as a tumor suppressor for preventing CIN in colorectal cancer.