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1.
Theranostics ; 10(3): 1033-1045, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31938049

RESUMO

Rationale: Abnormal expression of programmed death-1 (PD-1) ligand-1(PD-L1) in cancer cells plays a crucial role in cancer immune evasion and progression. The immune checkpoint molecules PD-1 and PD-L1 have been targeted for cancer treatment with significant benefits for cancer patients. However, the response rate is relatively low in certain types of cancer and the underlying mechanism remains poorly understood. Better understanding of the molecular mechanism of PD-L1 expression regulation in cancer cells is urgently needed to improve the treatment response rate and overall survival of patients. Fructose-1, 6-biphosphatase (FBP1) is a key enzyme in gluconeogenesis and is implicated in human cancer due to its frequent loss in various cancer types. Methods: Expression of FBP1 and PD-L1 was analyzed in various cancer cell lines. Western blot and RT-qPCR were performed to determine whether FBP1 regulates PD-L1 expression. Co-immunoprecipitation and glutathione S-transferase (GST) pulldown assay were employed to define the underlying regulatory mechanisms. Immunohistochemistry was conducted to determine the correlation between FBP1 and PD-L1 expression in a cohort of patients. A cancer syngeneic mouse model was utilized to examine how FBP1 affects tumor immunity. Results: We demonstrated that in a manner independent of its enzymatic activity FBP1 downregulates the expression of PD-L1 in various cell lines of different cancer types including pancreatic and prostate cancer. We further showed that this regulation occurs at the transcriptional level and is mediated by FBP1 inhibition of signal transducer and activator of transcription-3 (STAT3)-dependent PD-L1 transcription. Moreover, FBP1 and PD-L1 protein expression were negatively correlated in pancreatic ductal adenocarcinoma (PDAC) specimens from a cohort of patients. Most importantly, we demonstrated that decreased FBP1 expression promotes tumor growth and resistance to immune checkpoint blockade therapy in mice. Conclusions: Our findings reveal a new tumor suppressor function of FBP1 in inhibiting PD-L1 expression and enhancing cancer immunity. They also suggest that FBP1-deficient human cancers could be therapeutically targeted by PD-1/PD-L1-based immune checkpoint blockade therapy.

2.
Mol Cancer ; 18(1): 170, 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31771591

RESUMO

BACKGROUND: The gene encoding the E3 ubiquitin ligase substrate-binding adaptor SPOP is frequently mutated in primary prostate cancer, but how SPOP mutations contribute to prostate cancer pathogenesis remains poorly understood. Stress granules (SG) assembly is an evolutionarily conserved strategy for survival of cells under stress, and often upregulated in human cancers. We investigated the role of SPOP mutations in aberrant activation of the SG in prostate cancer and explored the relevanve of the mechanism in therapy resistance. METHODS: We identified SG nucleating protein Caprin1 as a SPOP interactor by using the yeast two hybrid methods. A series of functional analyses in cell lines, patient samples, and xenograft models were performed to investigate the biological significance and clinical relevance of SPOP regulation of SG signaling in prostate cancer. RESULTS: The cytoplasmic form of wild-type (WT) SPOP recognizes and triggers ubiquitin-dependent degradation of Caprin1. Caprin1 abundance is elevated in SPOP-mutant expressing prostate cancer cell lines and patient specimens. SPOP WT suppresses SG assembly, while the prostate cancer-associated mutants enhance SG assembly in a Caprin1-dependent manner. Knockout of SPOP or expression of prostate cancer-associated SPOP mutants conferred resistance to death caused by SG inducers (e.g. docetaxel, sodium arsenite and H2O2) in prostate cancer cells. CONCLUSIONS: SG assembly is aberrantly elevated in SPOP-mutated prostate cancer. SPOP mutations cause resistance to cellular stress induced by chemtherapeutic drug such as docetaxel in prostate cancer.

3.
Nat Commun ; 10(1): 5051, 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31699991

RESUMO

The oncogenic fusion protein AML1-ETO retains the ability of AML1 to interact with the enhancer core DNA sequences, but blocks AML1-dependent transcription. Previous studies have shown that post-translational modification of AML1-ETO may play a role in its regulation. Here we report that AML1-ETO-positive patients, with high histone lysine methyltransferase Enhancer of zeste homolog 1 (EZH1) expression, show a worse overall survival than those with lower EZH1 expression. EZH1 knockdown impairs survival and proliferation of AML1-ETO-expressing cells in vitro and in vivo. We find that EZH1 WD domain binds to the AML1-ETO NHR1 domain and methylates AML1-ETO at lysine 43 (Lys43). This requires the EZH1 SET domain, which augments AML1-ETO-dependent repression of tumor suppressor genes. Loss of Lys43 methylation by point mutation or domain deletion impairs AML1-ETO-repressive activity. These findings highlight the role of EZH1 in non-histone lysine methylation, indicating that cooperation between AML1-ETO and EZH1 and AML1-ETO site-specific lysine methylation promote AML1-ETO transcriptional repression in leukemia.

4.
Sensors (Basel) ; 19(22)2019 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-31744118

RESUMO

The detection of defects on irregular surfaces with specular reflection characteristics is an important part of the production process of sanitary equipment. Currently, defect detection algorithms for most irregular surfaces rely on the handcrafted extraction of shallow features, and the ability to recognize these defects is limited. To improve the detection accuracy of micro-defects on irregular surfaces in an industrial environment, we propose an improved Faster R-CNN model. Considering the variety of defect shapes and sizes, we selected the K-Means algorithm to generate the aspect ratio of the anchor box according to the size of the ground truth, and the feature matrices are fused with different receptive fields to improve the detection performance of the model. The experimental results show that the recognition accuracy of the improved model is 94.6% on a collected ceramic dataset. Compared with SVM (Support Vector Machine) and other deep learning-based models, the proposed model has better detection performance and robustness to illumination, which proves the practicability and effectiveness of the proposed method.

5.
EMBO Mol Med ; 11(11): e10659, 2019 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-31559706

RESUMO

CULLIN3-based E3 ubiquitin ligase substrate-binding adaptor gene SPOP is frequently mutated in prostate cancer (PCa). PCa harboring SPOP hotspot mutants (e.g., F133V) are resistant to BET inhibitors because of aberrant elevation of BET proteins. Here, we identified a previously unrecognized mutation Q165P at the edge of SPOP MATH domain in primary and metastatic PCa of a patient. The Q165P mutation causes structural changes in the MATH domain and impairs SPOP dimerization and substrate degradation. Different from F133V hotspot mutant tumors, Q165P mutant patient-derived xenografts (PDXs) and organoids were modestly sensitive to the BET inhibitor JQ1. Accordingly, protein levels of AR, BRD4 and downstream effectors such as RAC1 and phosphorylated AKT were not robustly elevated in Q165P mutant cells as in F133V mutant cells. However, NEO2734, a novel dual inhibitor of BET and CBP/p300, is active in both hotspot mutant (F133V) and non-hotspot mutant (Q165P) PCa cells in vitro and in vivo. These data provide a strong rationale to clinically investigate the anti-cancer efficacy of NEO2734 in SPOP-mutated PCa patients.

6.
Theranostics ; 9(17): 5020-5034, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31410199

RESUMO

Rationale: The Polycomb group (PcG) protein EZH2 is implicated in cancer progression due to its frequent overexpression in many cancer types and therefore is a promising therapeutic target. Forkhead box transcription factor-1 (FOXO1) is a tumor suppressor that is often transcriptionally downregulated in human cancers such as prostate cancer although the underlying regulatory mechanisms remain elusive. Methods: Analysis of EZH2 ChIP-seq and ChIP-on-chip data in various cell types was performed. ChIP-qPCR, RT-qPCR, and western blot analyses were conducted to determine the mechanism by which EZH2 represses FOXO1 expression. Immunohistochemistry was employed to assess the correlation between EZH2 and FOXO1 protein expression in prostate cancer patient specimens. In vitro MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) and animal experiments were performed to determine the anti-cancer efficacy of EZH2 inhibitor alone or in combination of docetaxel, a chemotherapy agent of the taxane family, and dependency of the efficacy on FOXO1 expression. Results: We demonstrated that EZH2 binds to the FOXO1 gene promoter. EZH2 represses FOXO1 gene expression at the transcriptional level. EZH2 protein level inversely correlated with FOXO1 protein expression in prostate cancer patient specimens. This repression requires the methyltransferase activity and the functional PRC2 complex. While effectively inducing loss of viability of PTEN-positive 22Rv1 prostate cancer cells, EZH2 inhibitor failed to inhibit growth of PTEN-negative C4-2 prostate cancer cells. Co-treatment with docetaxel overcame EZH2 inhibitor resistance in PTEN-negative cancer cells in vitro and in mice. This effect was largely mediated by docetaxel-induced nuclear localization and activation of FOXO1. Conclusions: This study identifies FOXO1 as a bona fide repression target of EZH2 and an essential mediator of EZH2 inhibition-induced cell death. Our findings suggest that EZH2 repression of FOXO1 can be targeted by EZH2 inhibitor as a monotherapy for PTEN-proficient cancers or in combination with taxane for treatment of cancers with PTEN mutation or deletion.

7.
Gastroenterology ; 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31419436

RESUMO

BACKGROUND & AIMS: Mutations in the trypsinogen gene (PRSS1) cause human hereditary pancreatitis. However, it is not clear how mutant forms of PRSS1 contribute to disease development. We studied the effects of expressing mutant forms of human PRSS1 in mice. METHODS: We expressed forms of PRSS1 with and without the mutation encoding R122H (PRSS1R122H) specifically in pancreatic acinar cells under control of a full-length pancreatic elastase gene promoter. Mice that did not express these transgenes were used as controls. Mice were given injections of caerulein to induce acute pancreatitis or injections of lipopolysaccharide (LPS) to induce chronic pancreatitis. Other groups of mice were fed ethanol or placed on a high-fat diet to induce pancreatitis. Pancreata were collected and analyzed by histology, immunoblots, real-time PCR, and immunohistochemistry. Trypsin enzymatic activity and chymotrypsin enzymatic activity were measured in pancreatic homogenates. Blood was collected and serum amylase activity was measured. RESULTS: Pancreata from mice expressing transgenes encoding PRSS1 or PRSS1R122H had focal areas of inflammation; these lesions were more prominent in mice that express PRSS1R122H. Pancreata from mice that express PRSS1 or PRSS1R122H had increased levels of HSP70 and NRF2 and reduced levels of chymotrypsin C (CTRC), compared with control mice. Increased expression of PRSS1 or PRSS1R122H increased focal damage in pancreatic tissues and increased the severity of acute pancreatitis after caerulein injection. Administration of LPS exacerbated inflammation in mice that express PRSS1R122H compared to mice that express PRSS1 or control mice. Mice that express PRSS1R122H developed more severe pancreatitis after ethanol feeding or a high-fat diet than mice that express PRSS1 or control mice. Pancreata from mice that express PRSS1R122H had more DNA damage, apoptosis, and collagen deposition and increased trypsin activity and infiltration by inflammatory cells than mice that express PRSS1 or control mice. CONCLUSIONS: Expression of a transgene encoding PRSS1R122H in mice promoted inflammation and increase the severity of pancreatitis, compared with mice that express PRSS1 or control mice. These mice might be used as a model for human hereditary pancreatitis and can be studied to determine mechanisms of induction of pancreatitis by LPS, ethanol, or a high-fat diet.

8.
Bioorg Med Chem Lett ; 29(19): 126627, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31444083

RESUMO

Based on thiolysis of the NBD amine, a H2S-triggered prodrug has been designed and synthesized for localized production of ciprofloxacin under micromolar H2S. Activation of the prodrug can be monitored through fluorescence in real-time. We envision that thiolysis of the NBD amine could be readily used for development of other H2S-triggered prodrugs in the future.

9.
Gastroenterology ; 157(5): 1413-1428.e11, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31352001

RESUMO

BACKGROUND & AIMS: Obesity is a risk factor for pancreatic cancer. In mice, a high-fat diet (HFD) and expression of oncogenic KRAS lead to development of invasive pancreatic ductal adenocarcinoma (PDAC) by unknown mechanisms. We investigated how oncogenic KRAS regulates the expression of fibroblast growth factor 21, FGF21, a metabolic regulator that prevents obesity, and the effects of recombinant human FGF21 (rhFGF21) on pancreatic tumorigenesis. METHODS: We performed immunohistochemical analyses of FGF21 levels in human pancreatic tissue arrays, comprising 59 PDAC specimens and 45 nontumor tissues. We also studied mice with tamoxifen-inducible expression of oncogenic KRAS in acinar cells (KrasG12D/+ mice) and fElasCreERT mice (controls). KrasG12D/+ mice were placed on an HFD or regular chow diet (control) and given injections of rhFGF21 or vehicle; pancreata were collected and analyzed by histology, immunoblots, quantitative polymerase chain reaction, and immunohistochemistry. We measured markers of inflammation in the pancreas, liver, and adipose tissue. Activity of RAS was measured based on the amount of bound guanosine triphosphate. RESULTS: Pancreatic tissues of mice expressed high levels of FGF21 compared with liver tissues. FGF21 and its receptor proteins were expressed by acinar cells. Acinar cells that expressed KrasG12D/+ had significantly lower expression of Fgf21 messenger RNA compared with acinar cells from control mice, partly due to down-regulation of PPARG expression-a transcription factor that activates Fgf21 transcription. Pancreata from KrasG12D/+ mice on a control diet and given injections of rhFGF21 had reduced pancreatic inflammation, infiltration by immune cells, and acinar-to-ductal metaplasia compared with mice given injections of vehicle. HFD-fed KrasG12D/+ mice given injections of vehicle accumulated abdominal fat, developed extensive inflammation, pancreatic cysts, and high-grade pancreatic intraepithelial neoplasias (PanINs); half the mice developed PDAC with liver metastases. HFD-fed KrasG12D/+ mice given injections of rhFGF21 had reduced accumulation of abdominal fat and pancreatic triglycerides, fewer pancreatic cysts, reduced systemic and pancreatic markers of inflammation, fewer PanINs, and longer survival-only approximately 12% of the mice developed PDACs, and none of the mice had metastases. Pancreata from HFD-fed KrasG12D/+ mice given injections of rhFGF21 had lower levels of active RAS than from mice given vehicle. CONCLUSIONS: Normal acinar cells from mice and humans express high levels of FGF21. In mice, acinar expression of oncogenic KRAS significantly reduces FGF21 expression. When these mice are placed on an HFD, they develop extensive inflammation, pancreatic cysts, PanINs, and PDACs, which are reduced by injection of FGF21. FGF21 also reduces the guanosine triphosphate binding capacity of RAS. FGF21 might be used in the prevention or treatment of pancreatic cancer.


Assuntos
Células Acinares/metabolismo , Carcinoma Ductal Pancreático/metabolismo , Transformação Celular Neoplásica/metabolismo , Dieta Hiperlipídica , Fatores de Crescimento de Fibroblastos/metabolismo , Neoplasias Intraductais Pancreáticas/metabolismo , Neoplasias Pancreáticas/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Células Acinares/patologia , Animais , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Carcinoma Ductal Pancreático/prevenção & controle , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/patologia , Regulação para Baixo , Fatores de Crescimento de Fibroblastos/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos Transgênicos , Mutação , PPAR gama/genética , PPAR gama/metabolismo , Cisto Pancreático/genética , Cisto Pancreático/metabolismo , Cisto Pancreático/patologia , Neoplasias Intraductais Pancreáticas/genética , Neoplasias Intraductais Pancreáticas/patologia , Neoplasias Intraductais Pancreáticas/prevenção & controle , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/prevenção & controle , Pancreatite/genética , Pancreatite/metabolismo , Pancreatite/patologia , Proteínas Proto-Oncogênicas p21(ras)/genética , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genética , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/metabolismo , Transdução de Sinais , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
10.
Theranostics ; 9(12): 3459-3475, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31281490

RESUMO

Rationale: The overall success rate of prostate cancer (PCa) diagnosis and therapy has been improved over the years. However, genomic and phenotypic heterogeneity remains a major challenge for effective detection and treatment of PCa. Efforts to better classify PCa into functional subtypes and elucidate the molecular mechanisms underlying prostate tumorigenesis and therapy resistance are warranted for further improvement of PCa outcomes. Methods: We generated Cre +;Runx2-cTg;Pten p/+ (Runx2-Pten double mutant) mice by crossbreeding Cre +;Runx2-cTg males with Pten conditional (Pten p/p) females. By using Hematoxylin and Eosin (H&E) staining, SMA and Masson's Trichrome staining, we investigated the effect of PTEN haploinsufficiency in combination with Runx2 overexpression on prostate tumorigenesis. Moreover, we employed immunohistochemistry (IHC) to stain Ki67 for cell proliferation, cleaved caspase 3 for apoptosis and AKT phosphorylation for signaling pathway in prostate tissues. Chromatin immunoprecipitation coupled quantitative PCR (ChIP-qPCR), reverse transcription coupled quantitative PCR (RT-qPCR), western blot (WB) analyses and immunofluorescence (IF) were conducted to determine the underlying mechanism by which RUNX2 regulates CXCR7 and AKT phosphorylation in PCa cells. Results: We demonstrated that mice with prostate-specific Pten heterozygous deletion and Runx2 overexpression developed high-grade prostatic intraepithelial neoplasia (HGPIN) and cancerous lesions at age younger than one year, with concomitant high level expression of Akt phosphorylation and the chemokine receptor Cxcr7 in malignant glands. RUNX2 overexpression induced CXCR7 transcription and membrane location and AKT phosphorylation in PTEN-deficient human PCa cell lines. Increased expression of RUNX2 also promoted growth of PCa cells and this effect was largely mediated by CXCR7. CXCR7 expression also positively correlated with AKT phosphorylation in PCa patient specimens. Conclusions: Our results reveal a previously unidentified cooperative role of RUNX2 overexpression and PTEN haploinsufficiency in prostate tumorigenesis, suggesting that the defined RUNX2-CXCR7-AKT axis can be a viable target for effective treatment of PCa.

11.
Org Biomol Chem ; 17(13): 3389-3395, 2019 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-30860220

RESUMO

Hydrogen sulfide (H2S) is an important endogenous signaling molecule with multiple biological functions. Based on the thiolysis of NBD (7-nitro-1,2,3-benzoxadiazole) amine, herein we rationally design and synthesize a new fluorescent probe 1 for the detection of mitochondrial H2S in living cells. Probe 1 displays bright red-emitting fluorescence after H2S activation (φ, 0.77). 1 shows higher selectivity and sensitivity for H2S than the red-emitting probe Rho-NBD (ChemBioChem, 2016, 17, 962). Moreover, 1 is water-soluble, cell-membrane-permeable, of low cytotoxicity and mitochondria-targeting, and can be employed for monitoring mitochondrial H2S in living cells.


Assuntos
Corantes Fluorescentes/química , Sulfeto de Hidrogênio/análise , Mitocôndrias/química , Imagem Óptica , Animais , Células HEK293 , Humanos , Peixe-Zebra
12.
EMBO J ; 38(5)2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30723117

RESUMO

In light of the increasing number of identified cancer-driven gain-of-function (GOF) mutants of p53, it is important to define a common mechanism to systematically target several mutants, rather than developing strategies tailored to inhibit each mutant individually. Here, using RNA immunoprecipitation-sequencing (RIP-seq), we identified the Polycomb-group histone methyltransferase EZH2 as a p53 mRNA-binding protein. EZH2 bound to an internal ribosome entry site (IRES) in the 5'UTR of p53 mRNA and enhanced p53 protein translation in a methyltransferase-independent manner. EZH2 augmented p53 GOF mutant-mediated cancer growth and metastasis by increasing protein levels of mutant p53. EZH2 overexpression was associated with worsened outcome selectively in patients with p53-mutated cancer. Depletion of EZH2 by antisense oligonucleotides inhibited p53 GOF mutant-mediated cancer growth. Our findings reveal a non-methyltransferase function of EZH2 that controls protein translation of p53 GOF mutants, inhibition of which causes synthetic lethality in cancer cells expressing p53 GOF mutants.


Assuntos
Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Mutação com Ganho de Função , Regulação Neoplásica da Expressão Gênica , Neoplasias da Próstata/patologia , RNA Mensageiro/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Apoptose , Proliferação de Células , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Humanos , Sítios Internos de Entrada Ribossomal , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Metástase Neoplásica , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Estabilidade Proteica , RNA Mensageiro/genética , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/química , Proteína Supressora de Tumor p53/genética , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Mol Cell ; 73(1): 22-35.e6, 2019 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-30527665

RESUMO

Aberrant expression of programmed death ligand-1 (PD-L1) in tumor cells promotes cancer progression by suppressing cancer immunity. The retinoblastoma protein RB is a tumor suppressor known to regulate the cell cycle, DNA damage response, and differentiation. Here, we demonstrate that RB interacts with nuclear factor κB (NF-κB) protein p65 and that their interaction is primarily dependent on CDK4/6-mediated serine-249/threonine-252 (S249/T252) phosphorylation of RB. RNA-seq analysis shows a subset of NF-κB pathway genes including PD-L1 are selectively upregulated by RB knockdown or CDK4/6 inhibitor. S249/T252-phosphorylated RB inversely correlates with PD-L1 expression in patient samples. Expression of a RB-derived S249/T252 phosphorylation-mimetic peptide suppresses radiotherapy-induced upregulation of PD-L1 and augments therapeutic efficacy of radiation in vivo. Our findings reveal a previously unrecognized tumor suppressor function of hyperphosphorylated RB in suppressing NF-κB activity and PD-L1 expression and suggest that the RB-NF-κB axis can be exploited to overcome cancer immune evasion triggered by conventional or targeted therapies.


Assuntos
Antígeno B7-H1/metabolismo , Neoplasias da Próstata/metabolismo , Proteína do Retinoblastoma/metabolismo , Fator de Transcrição RelA/metabolismo , Evasão Tumoral , Animais , Antineoplásicos Imunológicos/farmacologia , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/genética , Antígeno B7-H1/imunologia , Quimiorradioterapia/métodos , Quinase 4 Dependente de Ciclina/metabolismo , Quinase 6 Dependente de Ciclina/metabolismo , Regulação Neoplásica da Expressão Gênica , Células HEK293 , Humanos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Células PC-3 , Fosforilação , Neoplasias da Próstata/genética , Neoplasias da Próstata/imunologia , Neoplasias da Próstata/terapia , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Tolerância a Radiação , Proteína do Retinoblastoma/genética , Proteína do Retinoblastoma/imunologia , Transdução de Sinais , Fator de Transcrição RelA/genética , Fator de Transcrição RelA/imunologia , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Am J Physiol Gastrointest Liver Physiol ; 316(1): G179-G186, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30431318

RESUMO

Replacement of the exocrine parenchyma by fibrous tissue is a main characteristic of chronic pancreatitis. Understanding the mechanisms of pancreatic fibrogenesis is critical for the development of preventive and therapeutic interventions. Cyclooxygenase-2 (COX-2), a rate-limiting enzyme for prostaglandin synthesis, is expressed in patients with chronic pancreatitis. However, it is unknown whether COX-2 can cause chronic pancreatitis. To investigate the roles of pancreatic acinar COX-2 in fibrogenesis and the development of chronic pancreatitis, COX-2 was ectopically expressed specifically in pancreatic acinar cells in transgenic mice. Histopathological changes and expression levels of several profibrogenic factors related to chronic pancreatitis were evaluated. COX-2 was expressed in the pancreas of the transgenic mice, as detected by Western blot analysis. Immunohistochemical staining showed COX-2 was specifically expressed in pancreatic acinar cells. COX-2 expression led to progressive changes in the pancreas, including pancreas megaly, persistent inflammation, collagen deposition, and acinar-to-ductal metaplasia. Quantitative RT-PCR and immunostaining showed that profibrogenic factors were upregulated and pancreatic stellate cells were activated in the COX-2 transgenic mice. Expression of COX-2 in pancreatic acinar cells is sufficient to induce chronic pancreatitis. Targeting this pathway may be valuable in the prevention of chronic pancreatitis. NEW & NOTEWORTHY COX-2 expression is observed in pancreatic tissues of human chronic pancreatitis. In this study, we showed that COX-2 expression caused the development of chronic pancreatitis in transgenic mice, supporting the idea that COX-2 inhibition may be an effective preventive and therapeutic strategy.


Assuntos
Células Acinares/metabolismo , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/metabolismo , Pancreatite Crônica/metabolismo , Animais , Transformação Celular Neoplásica/metabolismo , Inflamação/metabolismo , Camundongos Transgênicos , Pâncreas/metabolismo , Pâncreas Exócrino/metabolismo , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Células Estreladas do Pâncreas/metabolismo
15.
Asian J Androl ; 21(3): 241-248, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-29900883

RESUMO

Therapy resistance is a significant challenge for prostate cancer treatment in clinic. Although targeted therapies such as androgen deprivation and androgen receptor (AR) inhibition are effective initially, tumor cells eventually evade these strategies through multiple mechanisms. Lineage reprogramming in response to hormone therapy represents a key mechanism that is increasingly observed. The studies in this area have revealed specific combinations of alterations present in adenocarcinomas that provide cells with the ability to transdifferentiate and perpetuate AR-independent tumor growth after androgen-based therapies. Interestingly, several master regulators have been identified that drive plasticity, some of which also play key roles during development and differentiation of the cell lineages in the normal prostate. Thus, further study of each AR-independent tumor type and understanding underlying mechanisms are warranted to develop combinational therapies that combat lineage plasticity in prostate cancer.

16.
Adv Exp Med Biol ; 1210: 319-331, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31900915

RESUMO

The PI3K signaling pathway is activated in a majority of cancer types. It promotes tumorigenesis by regulating nutrient metabolism, cell proliferation, survival, migration, and angiogenesis. The underlying mechanisms of PI3K/AKT activation are mainly due to deletions or mutations in its key negative regulator gene-PTEN. However, mutations in other pathway genes, such as the tumor suppressor gene SPOP, may contribute indirectly to the activation of this pathway. Interestingly, a mutually exclusive relationship exists between genomic alterations in PTEN and mutations in SPOP in prostate cancer patients, suggesting that altered functions of these two tumor suppressors might share similar or at least partially overlapping mechanisms in tumorigenesis. Activated AKT can phosphorylate directly a number of downstream effectors and thereby inhibit or activate their functions. An important target of PI3K/AKT signaling is FOXO1 protein that can be phosphorylated directly by AKT leading to translocation of FOXO1 from the cytoplasm to the nucleus. This not only impairs FOXO1 activities on transactivation of downstream target genes, but also abolishes its transcriptional activity-independent inhibitory effect on other targets such as AR, ERG and RUNX2. Interestingly, heterozygous deletion of Pten, or mutation of Spop alone has minimal effects on tumorigenesis in the mouse prostate, suggesting that PI3K/AKT pathway interacts with other pathways to drive prostate cancer progression. Indeed, the cross talk between PI3K/AKT and other pathways, such as AR, WNT, and ERK signaling pathways is known to play essential roles in disease progression and drug resistance in prostate cancer. Therefore, co-targeting the PI3K/AKT signaling pathway and its cooperating pathways may be critical for improving the anti-cancer efficacy of PI3K/AKT inhibitors in the clinic.


Assuntos
Proteína Forkhead Box O1/metabolismo , PTEN Fosfo-Hidrolase/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Neoplasias da Próstata/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores Androgênicos/metabolismo , Transdução de Sinais , Animais , Humanos , Masculino , Neoplasias da Próstata/patologia
17.
Nat Commun ; 9(1): 4381, 2018 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-30348973

RESUMO

Maintaining innate immune homeostasis is important for individual health. Npl4 zinc finger (NZF) domain-mediated ubiquitin chain sensing is reported to function in the nuclear factor-kappa B (NF-κB) signal pathway, but the regulatory mechanism remains elusive. Here we show that cyclophilin J (CYPJ), a member of the peptidylprolyl isomerase family, is induced by inflammation. CYPJ interacts with the NZF domain of transform growth factor-ß activated kinase 1 binding protein 2 and 3 as well as components of the linear ubiquitin chain assembly complex to block the binding of ubiquitin-chain and negatively regulates NF-κB signaling. Mice with Cypj deficiency are susceptible to lipopolysaccharide and heat-killed Listeria monocytogenes-induced sepsis and dextran sulfate sodium-induced colitis. These findings identify CYPJ as a negative feedback regulator of the NF-κB signaling pathway, and provide insights for understanding the homeostasis of innate immunity.


Assuntos
Colite/imunologia , Ciclofilinas/uso terapêutico , Sepse/imunologia , Ubiquitina/metabolismo , Animais , Colite/induzido quimicamente , Colite/tratamento farmacológico , Sulfato de Dextrana/toxicidade , Citometria de Fluxo , Células HEK293 , Células HeLa , Humanos , Lipopolissacarídeos/toxicidade , Listeria monocytogenes/patogenicidade , Camundongos , Microscopia Confocal , NF-kappa B , Poliubiquitina/metabolismo , Ligação Proteica , Interferência de RNA , Sepse/tratamento farmacológico , Sepse/microbiologia , Transdução de Sinais/efeitos dos fármacos , Células Vero
18.
Mol Cell ; 71(4): 592-605.e4, 2018 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-30057199

RESUMO

The bromodomain and extra-terminal domain (BET) protein BRD4 is emerging as a promising anticancer therapeutic target. However, resistance to BET inhibitors often occurs, and it has been linked to aberrant degradation of BRD4 protein in cancer. Here, we demonstrate that the deubiquitinase DUB3 binds to BRD4 and promotes its deubiquitination and stabilization. Expression of DUB3 is transcriptionally repressed by the NCOR2-HDAC10 complex. The NCOR2 gene is frequently deleted in castration-resistant prostate cancer patient specimens, and loss of NCOR2 induces elevation of DUB3 and BRD4 proteins in cancer cells. DUB3-proficient prostate cancer cells are resistant to the BET inhibitor JQ1 in vitro and in mice, but this effect is diminished by DUB3 inhibitory agents such as CDK4/6 inhibitor in a RB-independent manner. Our findings identify a previously unrecognized mechanism causing BRD4 upregulation and drug resistance, suggesting that DUB3 is a viable therapeutic target to overcome BET inhibitor resistance in cancer.


Assuntos
Quinase 4 Dependente de Ciclina/genética , Quinase 6 Dependente de Ciclina/genética , Endopeptidases/genética , Regulação Neoplásica da Expressão Gênica , Proteínas Nucleares/genética , Neoplasias de Próstata Resistentes à Castração/genética , Fatores de Transcrição/genética , Animais , Antineoplásicos/farmacologia , Azepinas/farmacologia , Proteínas de Ciclo Celular , Linhagem Celular Tumoral , Quinase 4 Dependente de Ciclina/antagonistas & inibidores , Quinase 4 Dependente de Ciclina/metabolismo , Quinase 6 Dependente de Ciclina/antagonistas & inibidores , Quinase 6 Dependente de Ciclina/metabolismo , Progressão da Doença , Resistencia a Medicamentos Antineoplásicos/genética , Endopeptidases/metabolismo , Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Humanos , Masculino , Camundongos , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/metabolismo , Correpressor 2 de Receptor Nuclear/deficiência , Correpressor 2 de Receptor Nuclear/genética , Piperazinas/farmacologia , Próstata/efeitos dos fármacos , Próstata/enzimologia , Próstata/patologia , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/enzimologia , Neoplasias de Próstata Resistentes à Castração/patologia , Inibidores de Proteínas Quinases/farmacologia , Proteólise , Piridinas/farmacologia , Transdução de Sinais , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/metabolismo , Transcrição Genética , Triazóis/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
19.
Clin Cancer Res ; 24(18): 4551-4565, 2018 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-29844131

RESUMO

Purpose: Deletions or mutations in PTEN and TP53 tumor suppressor genes have been linked to lineage plasticity in therapy-resistant prostate cancer. Fusion-driven overexpression of the oncogenic transcription factor ERG is observed in approximately 50% of all prostate cancers, many of which also harbor PTEN and TP53 alterations. However, the role of ERG in lineage plasticity of PTEN/TP53-altered tumors is unclear. Understanding the collective effect of multiple mutations within one tumor is essential to combat plasticity-driven therapy resistance.Experimental Design: We generated a Pten-negative/Trp53-mutated/ERG-overexpressing mouse model of prostate cancer and integrated RNA-sequencing with ERG chromatin immunoprecipitation-sequencing (ChIP-seq) to identify pathways regulated by ERG in the context of Pten/Trp53 alteration. We investigated ERG-dependent sensitivity to the antiandrogen enzalutamide and cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor palbociclib in human prostate cancer cell lines, xenografts, and allografted mouse tumors. Trends were evaluated in TCGA, SU2C, and Beltran 2016 published patient cohorts and a human tissue microarray.Results: Transgenic ERG expression in mice blocked Pten/Trp53 alteration-induced decrease of AR expression and downstream luminal epithelial genes. ERG directly suppressed expression of cell cycle-related genes, which induced RB hypophosphorylation and repressed E2F1-mediated expression of mesenchymal lineage regulators, thereby restricting adenocarcinoma plasticity and maintaining antiandrogen sensitivity. In ERG-negative tumors, CDK4/6 inhibition delayed tumor growth.Conclusions: Our studies identify a previously undefined function of ERG to restrict lineage plasticity and maintain antiandrogen sensitivity in PTEN/TP53-altered prostate cancer. Our findings suggest ERG fusion as a biomarker to guide treatment of PTEN/TP53-altered, RB1-intact prostate cancer. Clin Cancer Res; 24(18); 4551-65. ©2018 AACR.


Assuntos
PTEN Fosfo-Hidrolase/genética , Neoplasias da Próstata/tratamento farmacológico , Serina Endopeptidases/genética , Antagonistas de Androgênios/farmacologia , Animais , Linhagem da Célula/efeitos dos fármacos , Linhagem da Célula/genética , Quinase 4 Dependente de Ciclina/genética , Quinase 6 Dependente de Ciclina/genética , Modelos Animais de Doenças , Resistencia a Medicamentos Antineoplásicos/genética , Células Epiteliais/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Camundongos Transgênicos , Proteínas de Fusão Oncogênica/genética , Feniltioidantoína/análogos & derivados , Feniltioidantoína/farmacologia , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Regulador Transcricional ERG/genética , Proteína Supressora de Tumor p53/genética , Ensaios Antitumorais Modelo de Xenoenxerto
20.
Clin Cancer Res ; 24(14): 3299-3308, 2018 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-29618619

RESUMO

Purpose: Homozygous deletions play important roles in carcinogenesis. The genome-wide screening for homozygously deleted genes in many different cancer types with a large number of patient specimens representing the tumor heterogeneity has not been done.Experimental Design: We performed integrative analyses of the copy-number profiles of 10,759 patients across 31 cancer types from The Cancer Genome Atlas project.Results: We found that the type-I interferon, α-, and ß-defensin genes were homozygously deleted in 19 cancer types with high frequencies (7%-31%, median = 12%; interquartile range = 10%-16.5%). Patients with homozygous deletion of interferons exhibited significantly shortened overall or disease-free survival time in a number of cancer types, whereas patients with homozygous deletion of defensins did not significantly associate with worse overall or disease-free survival. Gene expression analyses suggested that homozygous deletion of interferon and defensin genes could activate genes involved in oncogenic and cell-cycle pathways but repress other genes involved in immune response pathways, suggesting their roles in promoting tumorigenesis and helping cancer cells evade immune surveillance. Further analysis of the whole exomes of 109 patients with melanoma demonstrated that the homozygous deletion of interferon (P = 0.0029, OR = 11.8) and defensin (P = 0.06, OR = 2.79) genes are significantly associated with resistance to anti-CTLA4 immunotherapy.Conclusions: Our analysis reveals that the homozygous deletion of interferon and defensin genes is prevalent in human cancers, and importantly this feature can be used as a novel prognostic biomarker for immunotherapy resistance. Clin Cancer Res; 24(14); 3299-308. ©2018 AACR.


Assuntos
Defensinas/genética , Resistencia a Medicamentos Antineoplásicos/genética , Frequência do Gene , Homozigoto , Interferon Tipo I/genética , Neoplasias/genética , Deleção de Sequência , Antineoplásicos Imunológicos/farmacologia , Antineoplásicos Imunológicos/uso terapêutico , Biologia Computacional/métodos , Bases de Dados Genéticas , Genômica/métodos , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/imunologia , Neoplasias/mortalidade , Prognóstico , Resultado do Tratamento
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