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1.
Genes Dev ; 31(13): 1325-1338, 2017 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-28794185

RESUMO

Deciphering the fundamental mechanisms controlling cardiac specification is critical for our understanding of how heart formation is initiated during embryonic development and for applying stem cell biology to regenerative medicine and disease modeling. Using systematic and unbiased functional screening approaches, we discovered that the Id family of helix-loop-helix proteins is both necessary and sufficient to direct cardiac mesoderm formation in frog embryos and human embryonic stem cells. Mechanistically, Id proteins specify cardiac cell fate by repressing two inhibitors of cardiogenic mesoderm formation-Tcf3 and Foxa2-and activating inducers Evx1, Grrp1, and Mesp1. Most importantly, CRISPR/Cas9-mediated ablation of the entire Id (Id1-4) family in mouse embryos leads to failure of anterior cardiac progenitor specification and the development of heartless embryos. Thus, Id proteins play a central and evolutionarily conserved role during heart formation and provide a novel means to efficiently produce cardiovascular progenitors for regenerative medicine and drug discovery applications.


Assuntos
Linhagem da Célula/genética , Coração/embriologia , Proteínas Inibidoras de Diferenciação/genética , Proteínas Inibidoras de Diferenciação/metabolismo , Organogênese/genética , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Diferenciação Celular/genética , Linhagem Celular , Embrião de Mamíferos/citologia , Embrião de Mamíferos/embriologia , Embrião não Mamífero/citologia , Embrião não Mamífero/embriologia , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/fisiologia , Edição de Genes , Regulação da Expressão Gênica no Desenvolvimento/genética , Cardiopatias Congênitas/genética , Humanos , Mesoderma/citologia , Mesoderma/fisiologia , Camundongos , Mutação , Sementes , Xenopus laevis/embriologia
2.
Exp Cell Res ; 429(1): 113652, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-37209991

RESUMO

Damage associated molecular patterns (DAMPs), including calreticulin (CRT) exposure, high-mobility group box 1 protein (HMGB1) elevation, and ATP release, characterize immunogenic cell death (ICD) and may play a role in cancer immunotherapy. Triple negative breast cancer (TNBC) is an immunogenic subtype of breast cancer with higher lymphocyte infiltration. Here, we found that regorafenib, a multi-target angiokinase inhibitor previously known to suppress STAT3 signaling, induced DAMPs and cell death in TNBC cells. Regorafenib induced the expression of HMGB1 and CRT, and the release of ATP. Regorafenib-induced HMGB1 and CRT were attenuated following STAT3 overexpression. In a 4T1 syngeneic murine model, regorafenib treatment increased HMGB1 and CRT expression in xenografts, and effectively suppressed 4T1 tumor growth. Immunohistochemical staining revealed increased CD4+ and CD8+ tumor-infiltrating T cells in 4T1 xenografts following regorafenib treatment. Regorafenib treatment or programmed death-1 (PD-1) blockade using anti-PD-1 monoclonal antibody reduced lung metastasis of 4T1 cells in immunocompetent mice. While regorafenib increases the proportion of MHC II high expression on dendritic cells in mice with smaller tumors, the combination of regorafenib and PD-1 blockade did not show a synergistic effect on anti-tumor activity. These results suggest that regorafenib induces ICD and suppresses tumor progression in TNBC. It should be carefully evaluated when developing a combination therapy with an anti-PD-1 antibody and a STAT3 inhibitor.


Assuntos
Proteína HMGB1 , Neoplasias de Mama Triplo Negativas , Camundongos , Humanos , Animais , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/metabolismo , Proteína HMGB1/farmacologia , Morte Celular , Trifosfato de Adenosina/farmacologia , Linhagem Celular Tumoral
3.
Mol Med ; 28(1): 93, 2022 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-35941532

RESUMO

BACKGROUND: Diffuse large B cell lymphoma (DLBCL) is an aggressive and molecularly heterogeneous non-Hodgkin's lymphoma. The B cell receptor (BCR) signaling pathway in DLBCL emerges as a new drug target. Protein phosphatase SHP-1 negatively regulates several oncogenic tyrosine kinases and plays a tumor suppressive role. METHODS: The direct SHP-1 agonists were used to evaluate the potential therapeutic implication of SHP-1 in DLBCL. Immunohistochemical staining for SHP-1 was quantified by H-score. The SHP-1 phosphatase activity was determined using tyrosine phosphatase assay. In vitro studies, including MTT, western blot analysis and cell apoptosis, were utilized to examined biological functions of SHP-1. RESULTS: Oral administration of SHP-1 agonist showed the potent anti-tumor effects compared to a selective Bruton's tyrosine kinase (BTK) inhibitor ibrutinib in mice bearing U2932 xenografts. SHP-1 agonist increased SHP-1 activity as well as downregulated p-Lyn in vivo. Here, we demonstrated that immunohistochemical staining for SHP-1 expression was positive in 76% of DLBCL samples. SHP-1 agonist exerted anti-proliferative and apoptotic effects compared with ibrutinib in DLBCL cells. Mechanistically, SHP-1 agonist decreased BCR signaling, especially p-Lyn, and led to apoptosis. CONCLUSIONS: These data suggest that SHP-1 negatively regulates phosphorylation of Lyn, and targeting SHP-1/p-Lyn using SHP-1 agonist has therapeutic potential for treatment of DLBCL.


Assuntos
Linfoma Difuso de Grandes Células B , Animais , Linhagem Celular Tumoral , Humanos , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/metabolismo , Linfoma Difuso de Grandes Células B/patologia , Camundongos , Proteína Tirosina Fosfatase não Receptora Tipo 6 , Receptores de Antígenos de Linfócitos B/metabolismo , Transdução de Sinais , Tirosina/farmacologia , Tirosina/uso terapêutico , Quinases da Família src/metabolismo
4.
J Virol ; 95(22): e0099621, 2021 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-34468177

RESUMO

Zika virus (ZIKV) is a mosquito-borne pathogen classified by the World Health Organization (WHO) as a public health emergency of international concern in 2016, and it is still identified as a priority disease. Although most infected individuals are asymptomatic or show mild symptoms, a risk of neurologic complications is associated with infection in adults. Additionally, infection during pregnancy is directly linked to microcephaly and other congenital malformations. Since there are no currently available vaccines or approved therapeutics for this virus, there is a critical unmet need in developing treatments to prevent future ZIKV outbreaks. Toward this end, we performed a large-scale cell-based high-content screen of 51,520 chemical compounds to identify potential antiviral drug candidates. The compound (2E)-N-benzyl-3-(4-butoxyphenyl)prop-2-enamide (SBI-0090799) was found to inhibit replication of multiple ZIKV strains and in different cell systems. SBI-0090799 did not affect viral entry or RNA translation but suppressed RNA replication by preventing the formation of the membranous replication compartment. Selection of drug-resistant viruses identified single-amino-acid substitutions in the N-terminal region of nonstructural protein NS4A, arguing this is the likely drug target. These resistance mutations rescued viral RNA replication and restored the formation of the membranous replication compartment. This mechanism of action is similar to clinically approved NS5A inhibitors for hepatitis C virus (HCV). Taken together, SBI-0090799 represents a promising lead candidate for the development of an antiviral treatment against ZIKV infection for the mitigation of severe complications and potential resurgent outbreaks of the virus. IMPORTANCE This study describes the elucidation of (2E)-N-benzyl-3-(4-butoxyphenyl)prop-2-enamide (SBI-0090799) as a selective and potent inhibitor of Zika virus (ZIKV) replication using a high-throughput screening approach. Mapping and resistance studies, supported by electron microscopy observations, indicate that the small molecule is functioning through inhibition of NS4A-mediated formation of ZIKV replication compartments in the endoplasmic reticulum (ER). Intriguingly, this defines a novel nonenzymatic target and chemical matter for the development of a new class of ZIKV antivirals. Moreover, chemical modulation affecting this nonstructural protein mirrors the identification and development of hepatitis C virus (HCV) NS5A inhibitor daclatasvir and its derivatives, similarly interfering with the formation of the viral replication compartment and also targeting a protein with no enzymatic activity, which have been part of a curative strategy for HCV.


Assuntos
Antivirais/farmacologia , Descoberta de Drogas/métodos , Avaliação Pré-Clínica de Medicamentos/métodos , Replicação Viral/efeitos dos fármacos , Infecção por Zika virus/tratamento farmacológico , Zika virus/efeitos dos fármacos , Animais , Astrócitos , Chlorocebus aethiops , Células Dendríticas , Células HEK293 , Humanos , Cultura Primária de Células , Células Vero , Compartimentos de Replicação Viral/efeitos dos fármacos
5.
Br J Cancer ; 123(11): 1633-1643, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32921792

RESUMO

BACKGROUND: Annexin A1 is expressed specifically on the tumour vasculature surface. Intravenously injected IF7 targets tumour vasculature via annexin A1. We tested the hypothesis that IF7 overcomes the blood-brain barrier and that the intravenously injected IF7C(RR)-SN38 eradicates brain tumours in the mouse. METHODS: (1) A dual-tumour model was generated by inoculating luciferase-expressing melanoma B16 cell line, B16-Luc, into the brain and under the skin of syngeneic C57BL/6 mice. IF7C(RR)-SN38 was injected intravenously daily at 7.0 µmoles/kg and growth of tumours was assessed by chemiluminescence using an IVIS imager. A similar dual-tumour model was generated with the C6-Luc line in immunocompromised SCID mice. (2) IF7C(RR)-SN38 formulated with 10% Solutol HS15 was injected intravenously daily at 2.5 µmoles/kg into two brain tumour mouse models: B16-Luc cells in C57BL/6 mice, and C6-Luc cells in nude mice. RESULTS: (1) Daily IF7C(RR)-SN38 injection suppressed tumour growth regardless of cell lines or mouse strains. (2) Daily injection of Solutol-formulated IF7C(RR)-SN38 led into complete disappearance of B16-Luc brain tumour in C57BL/6 mice, whereas this did not occur in C6-Luc in nude mice. CONCLUSIONS: IF7C(RR)-SN38 crosses the blood-brain barrier and suppresses growth of brain tumours in mouse models. Solutol HS15-formulated IF7C(RR)-SN38 may have promoted an antitumour immune response.


Assuntos
Anexina A1/metabolismo , Antineoplásicos/farmacologia , Barreira Hematoencefálica/metabolismo , Neoplasias Encefálicas , Portadores de Fármacos/farmacologia , Animais , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos SCID , Peptídeos , Ratos
6.
Proc Natl Acad Sci U S A ; 112(15): E1936-45, 2015 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-25825708

RESUMO

Newborn granule neurons generated from neural progenitor cells (NPCs) in the adult hippocampus play a key role in spatial learning and pattern separation. However, the molecular mechanisms that control activation of their neurogenic program remain poorly understood. Here, we report a novel function for the pluripotency factor sex-determining region Y (SRY)-related HMG box 2 (SOX2) in regulating the epigenetic landscape of poised genes activated at the onset of neuronal differentiation. We found that SOX2 binds to bivalently marked promoters of poised proneural genes [neurogenin 2 (Ngn2) and neurogenic differentiation 1 (NeuroD1)] and a subset of neurogenic genes [e.g., SRY-box 21 (Sox21), brain-derived neurotrophic factor (Bdnf), and growth arrest and DNA-damage-inducible, beta (Gadd45b)] where it functions to maintain the bivalent chromatin state by preventing excessive polycomb repressive complex 2 activity. Conditional ablation of SOX2 in adult hippocampal NPCs impaired the activation of proneural and neurogenic genes, resulting in increased neuroblast death and functionally aberrant newborn neurons. We propose that SOX2 sets a permissive epigenetic state in NPCs, thus enabling proper activation of the neuronal differentiation program under neurogenic cue.


Assuntos
Epigênese Genética , Células-Tronco Neurais/metabolismo , Neurogênese/genética , Fatores de Transcrição SOXB1/genética , Ativação Transcricional , Animais , Animais Recém-Nascidos , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Western Blotting , Ciclo Celular/genética , Proliferação de Células/genética , Células Cultivadas , Expressão Gênica , Hipocampo/citologia , Hipocampo/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Microscopia de Fluorescência , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , Neurônios/fisiologia , Técnicas de Patch-Clamp , Regiões Promotoras Genéticas/genética , Ligação Proteica , Interferência de RNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição SOXB1/deficiência , Fatores de Transcrição SOXB1/metabolismo
7.
J Infect Dis ; 216(8): 1000-1007, 2017 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-29149339

RESUMO

Background: Currently, the association between human immunodeficiency virus (HIV) infection and subsequent development of autoimmune hemolytic anemia (AIHA) remains unclear. This nationwide population-based cohort study aimed to determine the association between incident AIHA and HIV infection in Taiwan. Methods: During 2000-2012, we identified people aged ≧15 years living with HIV (PLWH) from the Taiwan Centers for Disease Control HIV Surveillance System. Individuals were considered to be infected with HIV on the basis of positive results of an HIV type 1 Western blot. Age- and sex-matched controls without HIV infection were selected from the Taiwan National Health Insurance Research Database for comparison. All patients were followed until 31 December 2012 and observed for occurrence of AIHA. Results: Of 171468 subjects (19052 PLWH and 152416 controls), 30 (0.02%) had incident AIHA during a mean follow-up of 5.45 years, including 23 PLWH (0.12%) and 7 controls (0.01%). After adjustment for age, sex, and comorbidities, HIV infection was found to be an independent risk factor of incident AIHA (adjusted hazard ratio, 20.9; 95% confidence interval, 8.34-52.3). Moreover, PLWH who were receiving highly active antiretroviral therapy were more likely to develop AIHA than those who were not receiving these drugs (adjusted hazard ratio, 16.2; 95% confidence interval, 3.52-74.2). Conclusions: Our study suggests that HIV infection is an independent risk factor for incident AIHA.


Assuntos
Anemia Hemolítica Autoimune/imunologia , Terapia Antirretroviral de Alta Atividade , Infecções por HIV/imunologia , Adolescente , Adulto , Anemia Hemolítica Autoimune/virologia , Estudos de Coortes , Planejamento em Saúde Comunitária , Comorbidade , Feminino , Infecções por HIV/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Fatores de Risco , Taiwan/epidemiologia , Adulto Jovem
8.
Br J Haematol ; 177(5): 726-740, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28340282

RESUMO

Enhancing the tumour suppressive activity of protein phosphatase 2A (PP2A) has been suggested to be an anti-leukaemic strategy. KIAA1524 (also termed CIP2A), an oncoprotein inhibiting PP2A, is associated with disease progression in chronic myeloid leukaemia and may be prognostic in cytogenetically normal acute myeloid leukaemia. Here we demonstrated that the selective proteasome inhibitor, carfilzomib, induced apoptosis in sensitive primary leukaemia cells and in sensitive leukaemia cell lines, associated with KIAA1524 protein downregulation, increased PP2A activity and decreased p-Akt, but not with the proteasome inhibition effect of carfilzomib. Ectopic expression of KIAA1524, or pretreatment with the PP2A inhibitor, okadaic acid, suppressed carfilzomib-induced apoptosis and KIAA1524 downregulation in sensitive cells, whereas co-treatment with the PP2A agonist, forskolin, enhanced carfilzomib-induced apoptosis in resistant cells. Mechanistically, carfilzomib affected KIAA1524 transcription through disturbing ELK1 (Elk-1) binding to the KIAA1524 promoter. Moreover, the drug sensitivity and mechanism of carfilzomib in xenograft mouse models correlated well with the effects of carfilzomib on KIAA1524 and p-Akt expression, as well as PP2A activity. Our data disclosed a novel drug mechanism of carfilzomib in leukaemia cells and suggests the potential therapeutic implication of KIAA1524 in leukaemia treatment.


Assuntos
Leucemia/tratamento farmacológico , Oligopeptídeos/farmacologia , Adulto , Idoso , Animais , Apoptose/efeitos dos fármacos , Autoantígenos/metabolismo , Linhagem Celular Tumoral , Cicloeximida/farmacologia , Regulação para Baixo/efeitos dos fármacos , Feminino , Células HL-60 , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Células K562 , Leucemia/fisiopatologia , Masculino , Proteínas de Membrana/metabolismo , Camundongos Nus , Pessoa de Meia-Idade , Transplante de Neoplasias/métodos , Ácido Okadáico/farmacologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Inibidores da Síntese de Proteínas/farmacologia , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
9.
BMC Infect Dis ; 17(1): 33, 2017 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-28056867

RESUMO

BACKGROUND: Patients with multiple myeloma are generally immune-compromised either due to pronounced depression in primary antibody responses or because of anti-myeloma therapy. Infection is a major risk factor for early deaths among these patients. The impact of blood stream infections (BSI) on newly diagnosed myeloma patients has been less studied. We aimed to study the incidence and risk factors of BSI within 3 months after diagnosis of multiple myeloma in a tertiary referral center. METHODS: Between November 2002 and December 2008, consecutive patients with multiple myeloma in Taipei Veterans General Hospital were retrospectively enrolled. Characteristics of patients with or without BSI were collected. Possible factors associated with development of BSI were analyzed by Cox regression. RESULTS: There were a total of 222 patients. The incidence of BSI within 3 months after diagnosis is 11.7%. The patients with BSI had poorer survival outcomes than those without (mortality rate: 50% vs. 20.9%, p < 0.001). Moreover, advanced International Staging System stage (stage III vs. I/II: odds ratio [OR] 2.69, p = 0.049) and poor Eastern Cooperative Oncology Group (ECOG) performance status (ECOG > 2 vs. ≤ 2: OR 3.58, p = 0.005) were the independent risk factors of BSI, whereas immunoglobulin deficiency and low absolute lymphocyte count were not associated with risk of BSI development. CONCLUSIONS: Our study highlights the characteristic of myeloma patients with BSI and the importance of disease and host factors on risk of BSI. Myeloma patients with risks of BSI should be properly managed to reduce early mortality.


Assuntos
Bacteriemia/etiologia , Mieloma Múltiplo/complicações , Idoso , Bacteriemia/epidemiologia , Bacteriemia/mortalidade , Infecções Relacionadas a Cateter/epidemiologia , Infecções Relacionadas a Cateter/etiologia , Infecções Relacionadas a Cateter/mortalidade , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/mortalidade , Razão de Chances , Estudos Retrospectivos , Fatores de Risco , Taiwan
10.
Proc Natl Acad Sci U S A ; 110(32): E3017-26, 2013 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-23884650

RESUMO

The transcription factor SRY (sex-determining region)-box 2 (SOX2) is an important functional marker of neural precursor cells (NPCs) and plays a critical role in self-renewal and neuronal differentiation; however, the molecular mechanisms underlying its functions are poorly understood. Using human embryonic stem cell-derived NPCs to model neurogenesis, we found that SOX2 is required to maintain optimal levels of LIN28, a well-characterized suppressor of let-7 microRNA biogenesis. Exogenous LIN28 expression rescued the NPC proliferation deficit, as well as the early but not the late stages of the neurogenic deficit associated with the loss of SOX2. We found that SOX2 binds to a proximal site in the LIN28 promoter region and regulates LIN28 promoter acetylation, likely through interactions with the histone acetyltransferase complex. Misexpression of let-7 microRNAs in NPCs reduced proliferation and inhibited neuronal differentiation, phenocopying the loss of SOX2. In particular, we identified let-7i as a novel and potent inhibitor of neuronal differentiation that targets MASH1 and NGN1, two well-characterized proneural genes. In conclusion, we discovered the SOX2-LIN28/let-7 pathway as a unique molecular mechanism governing NPC proliferation and neurogenic potential.


Assuntos
Proliferação de Células , MicroRNAs/genética , Células-Tronco Neurais/metabolismo , Neurogênese/genética , Proteínas de Ligação a RNA/genética , Fatores de Transcrição SOXB1/genética , Animais , Sequência de Bases , Diferenciação Celular/genética , Células Cultivadas , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Células HEK293 , Humanos , Imuno-Histoquímica , Camundongos , Camundongos Knockout , Células-Tronco Neurais/citologia , Neurônios/citologia , Neurônios/metabolismo , Interferência de RNA , Proteínas de Ligação a RNA/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição SOXB1/metabolismo , Transdução de Sinais/genética
11.
Breast Cancer Res ; 16(5): 431, 2014 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-25228280

RESUMO

INTRODUCTION: Tamoxifen, a selective estrogen receptor (ER) modulator, may affect cancer cell survival through mechanisms other than ER antagonism. In the present study, we tested the efficacy of tamoxifen in a panel of ER-negative breast cancer cell lines and examined the drug mechanism. METHODS: In total, five ER-negative breast cancer cell lines (HCC-1937, MDA-MB-231, MDA-MB-468, MDA-MB-453 and SK-BR-3) were used for in vitro studies. Cellular apoptosis was examined by flow cytometry and Western blot analysis. Signal transduction pathways in cells were assessed by Western blot analysis. The in vivo efficacy of tamoxifen was tested in xenograft nude mice. RESULTS: Tamoxifen induced significant apoptosis in MDA-MB-231, MDA-MB-468, MDA-MB-453 and SK-BR-3 cells, but not in HCC-1937 cells. Tamoxifen-induced apoptosis was associated with inhibition of cancerous inhibitor of protein phosphatase 2A (CIP2A) and phospho-Akt (p-Akt) in a dose-dependent manner. Ectopic expression of either CIP2A or Akt protected MDA-MB-231 cells from tamoxifen-induced apoptosis. In addition, tamoxifen increased protein phosphatase 2A (PP2A) activity, and tamoxifen-induced apoptosis was attenuated by the PP2A antagonist okadaic acid in the sensitive cell lines, but not in resistant HCC-1937 cells. Moreover, silencing CIP2A by small interfering RNA sensitized HCC-1937 cells to tamoxifen-induced apoptosis. Furthermore, tamoxifen regulated CIP2A protein expression by downregulating CIP2A mRNA. Importantly, tamoxifen inhibited the in vivo growth of MDA-MB-468 xenograft tumors in association with CIP2A downregulation, whereas tamoxifen had no significant effect on CIP2A expression and anti-tumor growth in HCC-1937 tumors. CONCLUSIONS: Inhibition of CIP2A determines the effects of tamoxifen-induced apoptosis in ER-negative breast cancer cells. Our data suggest a novel "off-target" mechanism of tamoxifen and suggest that CIP2A/PP2A/p-Akt signaling may be a feasible anti-cancer pathway.


Assuntos
Antineoplásicos Hormonais/farmacologia , Apoptose/efeitos dos fármacos , Autoantígenos/metabolismo , Neoplasias da Mama/tratamento farmacológico , Proteínas de Membrana/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Tamoxifeno/farmacologia , Idoso , Animais , Autoantígenos/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Regulação para Baixo , Feminino , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Estimativa de Kaplan-Meier , Masculino , Proteínas de Membrana/genética , Camundongos Nus , Pessoa de Meia-Idade , Receptores de Estrogênio/metabolismo , Transcrição Gênica , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
12.
J Neurochem ; 129(1): 48-59, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24266713

RESUMO

Chromogranin B (CHGB) is the major matrix protein in human catecholamine storage vesicles. CHGB genetic variation alters catecholamine secretion and blood pressure. Here, effective Chgb protein under-expression was achieved by siRNA in PC12 cells, resulting in ~ 48% fewer secretory granules on electron microscopy, diminished capacity for catecholamine uptake (by ~ 79%), and a ~ 73% decline in stores available for nicotinic cholinergic-stimulated secretion. In vivo, loss of Chgb in knockout mice resulted in a ~ 35% decline in chromaffin granule abundance and ~ 44% decline in granule diameter, accompanied by unregulated catecholamine release into plasma. Over-expression of CHGB was achieved by transduction of a CHGB-expressing lentivirus, resulting in ~ 127% elevation in CHGB protein, with ~ 122% greater abundance of secretory granules, but only ~ 14% increased uptake of catecholamines, and no effect on nicotinic-triggered secretion. Human CHGB protein and its proteolytic fragments inhibited nicotinic-stimulated catecholamine release by ~ 72%. One conserved-region CHGB peptide inhibited nicotinic-triggered secretion by up to ~ 41%, with partial blockade of cationic signal transduction. We conclude that bi-directional quantitative derangements in CHGB abundance result in profound changes in vesicular storage and release of catecholamines. When processed and released extra-cellularly, CHGB proteolytic fragments exert a feedback effect to inhibit catecholamine secretion, especially during nicotinic cholinergic stimulation.


Assuntos
Catecolaminas/metabolismo , Grânulos Cromafim/metabolismo , Cromogranina B/fisiologia , Líquido Extracelular/fisiologia , Líquido Intracelular/fisiologia , Sequência de Aminoácidos , Animais , Catecolaminas/genética , Grânulos Cromafim/genética , Humanos , Camundongos , Camundongos Knockout , Dados de Sequência Molecular , Ratos
13.
bioRxiv ; 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38826238

RESUMO

Over 95% of pancreatic ductal adenocarcinomas (PDAC) harbor oncogenic mutations in K-Ras. Upon treatment with K-Ras inhibitors, PDAC cancer cells undergo metabolic reprogramming towards an oxidative phosphorylation-dependent, drug-resistant state. However, direct inhibition of complex I is poorly tolerated in patients due to on-target induction of peripheral neuropathy. In this work, we develop molecular glue degraders against ZBTB11, a C2H2 zinc finger transcription factor that regulates the nuclear transcription of components of the mitoribosome and electron transport chain. Our ZBTB11 degraders leverage the differences in demand for biogenesis of mitochondrial components between human neurons and rapidly-dividing pancreatic cancer cells, to selectively target the K-Ras inhibitor resistant state in PDAC. Combination treatment of both K-Ras inhibitor-resistant cell lines and multidrug resistant patient-derived organoids resulted in superior anti-cancer activity compared to single agent treatment, while sparing hiPSC-derived neurons. Proteomic and stable isotope tracing studies revealed mitoribosome depletion and impairment of the TCA cycle as key events that mediate this response. Together, this work validates ZBTB11 as a vulnerability in K-Ras inhibitor-resistant PDAC and provides a suite of molecular glue degrader tool compounds to investigate its function.

14.
Viruses ; 15(5)2023 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-37243192

RESUMO

The Zika virus (ZIKV), a member of the Flaviviridae family, is considered a major health threat causing multiple cases of microcephaly in newborns and Guillain-Barré syndrome in adults. In this study, we targeted a transient, deep, and hydrophobic pocket of the "super-open" conformation of ZIKV NS2B-NS3 protease to overcome the limitations of the active site pocket. After virtual docking screening of approximately seven million compounds against the novel allosteric site, we selected the top six candidates and assessed them in enzymatic assays. Six candidates inhibited ZIKV NS2B-NS3 protease proteolytic activity at low micromolar concentrations. These six compounds, targeting the selected protease pocket conserved in ZIKV, serve as unique drug candidates and open new opportunities for possible treatment against several flavivirus infections.


Assuntos
Infecção por Zika virus , Zika virus , Recém-Nascido , Humanos , Zika virus/metabolismo , Infecção por Zika virus/tratamento farmacológico , Proteínas não Estruturais Virais/química , Serina Endopeptidases/metabolismo , Peptídeo Hidrolases , Conformação Proteica , Inibidores de Proteases/farmacologia , Inibidores de Proteases/química
15.
Nat Commun ; 14(1): 1709, 2023 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-36973293

RESUMO

Defining the mechanisms safeguarding cell fate identity in differentiated cells is crucial to improve 1) - our understanding of how differentiation is maintained in healthy tissues or altered in a disease state, and 2) - our ability to use cell fate reprogramming for regenerative purposes. Here, using a genome-wide transcription factor screen followed by validation steps in a variety of reprogramming assays (cardiac, neural and iPSC in fibroblasts and endothelial cells), we identified a set of four transcription factors (ATF7IP, JUNB, SP7, and ZNF207 [AJSZ]) that robustly opposes cell fate reprogramming in both lineage and cell type independent manners. Mechanistically, our integrated multi-omics approach (ChIP, ATAC and RNA-seq) revealed that AJSZ oppose cell fate reprogramming by 1) - maintaining chromatin enriched for reprogramming TF motifs in a closed state and 2) - downregulating genes required for reprogramming. Finally, KD of AJSZ in combination with MGT overexpression, significantly reduced scar size and improved heart function by 50%, as compared to MGT alone post-myocardial infarction. Collectively, our study suggests that inhibition of barrier to reprogramming mechanisms represents a promising therapeutic avenue to improve adult organ function post-injury.


Assuntos
Células-Tronco Pluripotentes Induzidas , Fatores de Transcrição , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Reprogramação Celular/genética , Células Endoteliais/metabolismo , Diferenciação Celular/genética , Células-Tronco Pluripotentes Induzidas/metabolismo , Fibroblastos/metabolismo
16.
Cell Rep ; 39(2): 110655, 2022 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-35417697

RESUMO

Zika virus (ZIKV) and dengue virus (DENV) are arthropod-borne pathogenic flaviviruses that co-circulate in many countries. To understand some of the pressures that influence ZIKV evolution, we mimic the natural transmission cycle by repeating serial passaging of ZIKV through cultured mosquito cells and either DENV-naive or DENV-immune mice. Compared with wild-type ZIKV, the strains passaged under both conditions exhibit increased pathogenesis in DENV-immune mice. Application of reverse genetics identifies an isoleucine-to-valine mutation (I39V) in the NS2B proteins of both passaged strains that confers enhanced fitness and escape from pre-existing DENV immunity. Introduction of I39V or I39T, a naturally occurring homologous mutation detected in recent ZIKV isolates, increases the replication of wild-type ZIKV in human neuronal precursor cells and laboratory-raised mosquitoes. Our data indicate that ZIKV strains with enhanced transmissibility and pathogenicity can emerge in DENV-naive or -immune settings, and that NS2B-I39 mutants may represent ZIKV variants of interest.


Assuntos
Vírus da Dengue , Dengue , Infecção por Zika virus , Zika virus , Animais , Anticorpos Antivirais , Reações Cruzadas , Vírus da Dengue/genética , Camundongos , Mutação/genética , Zika virus/genética
17.
PLoS One ; 16(1): e0241157, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33406123

RESUMO

We previously reported that IF7 peptide, which binds to the annexin A1 (ANXA1) N-terminus, functions as a tumor vasculature-targeted drug delivery vehicle after intravenous injection. To enhance IF7 stability in vivo, we undertook mirror-image peptide phage display using a synthetic D-peptide representing the ANXA1 N-terminus as target. We then identified peptide sequences, synthesized them as D-amino acids, and designated the resulting peptide dTIT7, which we showed bound to the ANXA1 N-terminus. Whole body imaging of mouse brain tumor models injected with near infrared fluorescent IRDye-conjugated dTIT7 showed fluorescent signals in brain and kidney. Furthermore, orally-administered dTIT7/geldanamycin (GA) conjugates suppressed brain tumor growth. Ours is a proof-of-concept experiment showing that ANXA1-binding D-peptide can be developed as an orally-administrable tumor vasculature-targeted therapeutic.


Assuntos
Anexina A1/antagonistas & inibidores , Neoplasias Encefálicas/irrigação sanguínea , Neoplasias Encefálicas/tratamento farmacológico , Sistemas de Liberação de Medicamentos , Proteínas de Neoplasias/antagonistas & inibidores , Neovascularização Patológica/tratamento farmacológico , Peptídeos , Administração Oral , Animais , Anexina A1/metabolismo , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteínas de Neoplasias/metabolismo , Neovascularização Patológica/metabolismo , Neovascularização Patológica/patologia , Peptídeos/síntese química , Peptídeos/química , Peptídeos/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
18.
Sci Rep ; 11(1): 12171, 2021 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-34108545

RESUMO

Glycoprotein non-metastatic B (GPNMB) is a transmembrane protein overexpressed in numerous cancers including triple-negative breast cancers (TNBC). It has been linked to promote cancer aggressiveness and implicated as a novel target for GPNMB-expressing cancers. In current study, we aimed to explore the clinical significance of GPNMB in TNBC. Among 759 specimens, immunohistochemistry (IHC) exhibited GPNMB expressions were variable in different subtypes and significantly higher in TNBC. Kaplan-Meier analysis revealed GPNMB overexpression in TNBC was associated with worse prognosis especially distant metastasis (P = 0.020, HR = 2.515, CI 1.154-5.480). Multivariate analysis showed GPNMB expression was an independent prognostic factor in terms of recurrence and distant metastasis (P = 0.008, HR = 3.22, CI 1.36-7.61; P = 0.017, HR = 3.08, CI 1.22-7.74). In silico analysis showed high mRNA expression of GPNMB was associated with distant metastasis and GPNMB was overexpressed in TNBC. Furthermore, GPNMB positively correlated with epithelial-mesenchymal transition (EMT) regulators, mesenchymal marker vimentin, MMP and integrins. The protein levels of Twist and MMP2 were upregulated by GPNMB overexpression in TNBC cells. GPNMB-enhanced cell invasion was attenuated by broad spectrum MMP inhibitor (GM 6001) and the selective inhibitor of MMP-2 (ARP100). In summary, GPNMB expression is prevalent in TNBC and may be implicated as a prognostic biomarker in patients with TNBC.


Assuntos
Biomarcadores Tumorais/metabolismo , Regulação Neoplásica da Expressão Gênica , Glicoproteínas de Membrana/metabolismo , Recidiva Local de Neoplasia/patologia , Neoplasias de Mama Triplo Negativas/patologia , Idoso , Apoptose , Biomarcadores Tumorais/genética , Proliferação de Células , Transição Epitelial-Mesenquimal , Humanos , Glicoproteínas de Membrana/genética , Pessoa de Meia-Idade , Invasividade Neoplásica , Recidiva Local de Neoplasia/metabolismo , Recidiva Local de Neoplasia/cirurgia , Prognóstico , Taxa de Sobrevida , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/cirurgia , Células Tumorais Cultivadas
19.
J Pain Symptom Manage ; 61(2): 323-330, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32739560

RESUMO

CONTEXT: The impact of hospice care services on the utilization of life-sustaining treatments during end-of-life care in terminally ill patients has not been extensively studied. OBJECTIVES: To determine the impact of hospice care services on the utilization of life-sustaining treatments during the last three months of life among patients with cancer. METHODS: This nationwide population-based cohort study identified adults with cancer diagnosis from the Taiwan Registry for Catastrophic Illness, 2006-2016. Life-sustaining treatments included cardiopulmonary resuscitation, intubation, mechanical ventilation support, nasogastric tube feeding, and total parenteral nutrition. Hospice care services consisted of hospice inpatient care, hospice-shared care, and hospice home care. The association of hospice care services with the utilization of life-sustaining treatments was determined using multiple logistic regression. RESULTS: Of 516,409 patients with cancer, 310,722 (60.2%) patients used life-sustaining treatments during the last three months of life. After adjusting for covariates, patients with hospice care services were less likely to receive life-sustaining treatments during the last three months of life than those without the services (adjusted odds ratio [AOR]: 0.70; 95% CI: 0.69-0.71). While type of life-sustaining treatments were considered, hospice care services were associated with a lower likelihood of receiving cardiopulmonary resuscitation (AOR: 0.125; 95% CI: 0.118-0.131), endotracheal intubation (AOR: 0.204; 95% CI: 0.199-0.210), mechanical ventilation support (AOR: 0.265; 95% CI: 0.260-0.270), nasogastric tube feeding (AOR: 0.736; 95% CI: 0.727-0.744), and total parenteral nutrition (AOR: 0.86; 95% CI: 0.84-0.88). CONCLUSION: Hospice care services were associated with a lower likelihood of receiving life-sustaining treatments during the last three months of life in patients with cancer.


Assuntos
Cuidados Paliativos na Terminalidade da Vida , Neoplasias , Assistência Terminal , Adulto , Estudos de Coortes , Humanos , Neoplasias/terapia , Taiwan
20.
Front Pharmacol ; 11: 597703, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33568997

RESUMO

Rhizoma Coptidis is a popular phytomedicine for the treatment of type 2 diabetes in Asia, but its effective dose for diabetes treatment remains confused because of diverse origins. This study aimed to investigate the dose-response effects of Rhizoma Coptidis extract granules (RCEG), produced with standardized quality control, on hypoglycemic effects in patients with type 2 diabetes. We conducted a retrospective analysis of Chang Gung Research Database from January 01, 2008 to November 30, 2017. Outpatients visiting traditional Chinese medicine clinics and receiving RCEG for type 2 diabetes treatment were included. Plasma glucose, lipid, and other parameters were analyzed from 93 patients with a total of 737 visits within 60 weeks. Scatter plots with the LOESS analysis were used to explore the association between RCEG dose and hypoglycemic effect. The minimal effective dose was chosen to divide the study population into the high-dose and low-dose RCEG groups. Non-parametric tests were used for between-group and within-group comparisons. The multivariate nonlinear mixed-effects model was applied to access the effect of treatment length and groups simultaneously on the change of HbA1c and fasting plasma glucose. The "arule" package in R was used to present the network diagram of RCEG and other co-prescriptions. We first discovered a significant relationship between RCEG dose and HbA1c reduction when the dose reached 0.08 g/kg/day or higher. We thus defined 0.08 g/kg/day of RCEG as the minimum effective dose, and a threshold to separate patients into the high-dose (≥0.08 g/kg/d) and low-dose (<0.08 g/kg/d) RCEG groups. In the high-dose RCEG group, a significant decrease in total cholesterol and a trend toward triglyceride reduction were also noted. Patients more effectively responded to RCEG treatment if they had a higher initial HbA1c level, higher heart rates, better liver function tests, and better tolerance to the higher dose and treatment duration of RCEG. In addition, digestive/tonic/dampness draining formulas and blood regulation recipes were two of the most frequent co-prescriptions with RCEG. This study concluded that RCEG at a dose exceeding 0.08 g/kg/d had beneficial effects on glycemic and lipid control, without showing nephro- or hepatotoxicity, in patients with type 2 diabetes.

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