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1.
Int J Stem Cells ; 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38698632

RESUMO

The elucidation of the pathophysiology underlying various diseases necessitates the development of research platforms that faithfully mimic in vivo conditions. Traditional model systems such as two-dimensional cell cultures and animal models have proven inadequate in capturing the complexities of human disease modeling. However, recent strides in organoid culture systems have opened up new avenues for comprehending gastric stem cell homeostasis and associated diseases, notably gastric cancer. Given the significance of gastric cancer, a thorough understanding of its pathophysiology and molecular underpinnings is imperative. To this end, the utilization of patient-derived organoid libraries emerges as a remarkable platform, as it faithfully mirrors patient-specific characteristics, including mutation profiles and drug sensitivities. Furthermore, genetic manipulation of gastric organoids facilitates the exploration of molecular mechanisms underlying gastric cancer development. This review provides a comprehensive overview of recent advancements in various adult stem cell-derived gastric organoid models and their diverse applications.

2.
NAR Cancer ; 5(3): zcad042, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37554969

RESUMO

Targeting BRCA1- and BRCA2-deficient tumors through synthetic lethality using poly(ADP-ribose) polymerase inhibitors (PARPi) has emerged as a successful strategy for cancer therapy. PARPi monotherapy has shown excellent efficacy and safety profiles in clinical practice but is limited by the need for tumor genome mutations in BRCA or other homologous recombination genes as well as the rapid emergence of resistance. In this study, we identified 2-chloro-N,N-diethylethanamine hydrochloride (CDEAH) as a small molecule that selectively kills PARP1- and xeroderma pigmentosum A-deficient cells. CDEAH is a monofunctional alkylating agent that preferentially alkylates guanine nucleobases, forming DNA adducts that can be removed from DNA by either a PARP1-dependent base excision repair or nucleotide excision repair. Treatment of PARP1-deficient cells leads to the formation of strand breaks, an accumulation of cells in S phase and activation of the DNA damage response. Furthermore, CDEAH selectively inhibits PARP1-deficient xenograft tumor growth compared to isogenic PARP1-proficient tumors. Collectively, we report the discovery of an alkylating agent inducing DNA damage that requires PARP1 activity for repair and acts synergistically with PARPi.

3.
Exp Mol Med ; 55(8): 1720-1733, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37524868

RESUMO

Autophagy functions in cellular quality control and metabolic regulation. Dysregulation of autophagy is one of the major pathogenic factors contributing to the progression of nonalcoholic fatty liver disease (NAFLD). Autophagy is involved in the breakdown of intracellular lipids and the maintenance of healthy mitochondria in NAFLD. However, the mechanisms underlying autophagy dysregulation in NAFLD remain unclear. Here, we demonstrate that the hepatic expression level of Thrap3 was significantly increased in NAFLD conditions. Liver-specific Thrap3 knockout improved lipid accumulation and metabolic properties in a high-fat diet (HFD)-induced NAFLD model. Furthermore, Thrap3 deficiency enhanced autophagy and mitochondrial function. Interestingly, Thrap3 knockout increased the cytosolic translocation of AMPK from the nucleus and enhanced its activation through physical interaction. The translocation of AMPK was regulated by direct binding with AMPK and the C-terminal domain of Thrap3. Our results indicate a role for Thrap3 in NAFLD progression and suggest that Thrap3 is a potential target for NAFLD treatment.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Animais , Camundongos , Proteínas Quinases Ativadas por AMP/metabolismo , Autofagia/genética , Dieta Hiperlipídica/efeitos adversos , Metabolismo dos Lipídeos , Fígado/metabolismo , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Fatores de Transcrição/metabolismo , Humanos , Células Hep G2
4.
Nucleic Acids Res ; 51(15): 7936-7950, 2023 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-37378431

RESUMO

Replication protein A (RPA), a eukaryotic single-stranded DNA (ssDNA) binding protein, dynamically interacts with ssDNA in different binding modes and plays essential roles in DNA metabolism such as replication, repair, and recombination. RPA accumulation on ssDNA due to replication stress triggers the DNA damage response (DDR) by activating the ataxia telangiectasia and RAD3-related (ATR) kinase, which phosphorylates itself and downstream DDR factors, including RPA. We recently reported that the N-methyl-D-aspartate receptor synaptonuclear signaling and neuronal migration factor (NSMF), a neuronal protein associated with Kallmann syndrome, promotes RPA32 phosphorylation via ATR upon replication stress. However, how NSMF enhances ATR-mediated RPA32 phosphorylation remains elusive. Here, we demonstrate that NSMF colocalizes and physically interacts with RPA at DNA damage sites in vivo and in vitro. Using purified RPA and NSMF in biochemical and single-molecule assays, we find that NSMF selectively displaces RPA in the more weakly bound 8- and 20-nucleotide binding modes from ssDNA, allowing the retention of more stable RPA molecules in the 30-nt binding mode. The 30-nt binding mode of RPA enhances RPA32 phosphorylation by ATR, and phosphorylated RPA becomes stabilized on ssDNA. Our findings provide new mechanistic insight into how NSMF facilitates the role of RPA in the ATR pathway.


Assuntos
Proteínas Serina-Treonina Quinases , Proteína de Replicação A , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Quinase 1 do Ponto de Checagem/metabolismo , Dano ao DNA , Replicação do DNA , DNA de Cadeia Simples , Proteínas de Ligação a DNA/genética , Fosforilação , Ligação Proteica , Proteínas Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteína de Replicação A/metabolismo , Humanos
5.
Biochem Biophys Res Commun ; 665: 10-18, 2023 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-37148741

RESUMO

Autophagy has bidirectional functions in cancer by facilitating cell survival and death in a context-dependent manner. Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) are a large family of proteins essential for numerous biological processes, including autophagy; nevertheless, their potential function in cancer malignancy remains unclear. Here, we explored the gene expression patterns of SNAREs in tissues of patients with colorectal cancer (CRC) and discovered that SEC22B expression, a vesicle SNARE, was higher in tumor tissues than in normal tissues, with a more significant increase in metastatic tissues. Interestingly, SEC22B knockdown dramatically decreased CRC cell survival and growth, especially under stressful conditions, such as hypoxia and serum starvation, and decreased the number of stress-induced autophagic vacuoles. Moreover, SEC22B knockdown successfully attenuated liver metastasis in a CRC cell xenograft mouse model, with histological signs of decreased autophagic flux and proliferation within cancer cells. Together, this study posits that SEC22B plays a crucial role in enhancing the aggressiveness of CRC cells, suggesting that SEC22B might be an attractive therapeutic target for CRC.


Assuntos
Neoplasias Colorretais , Proteínas SNARE , Animais , Humanos , Camundongos , Autofagossomos/metabolismo , Autofagia/genética , Linhagem Celular Tumoral , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Proteínas R-SNARE/metabolismo , Proteínas SNARE/metabolismo
6.
Theranostics ; 12(12): 5258-5271, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35910805

RESUMO

Rationale: Doublecortin-like kinase 1 (DCLK1) is a serine/threonine kinase that selectively marks cancer stem-like cells (CSCs) and promotes malignant progression in colorectal cancer (CRC). However, the exact molecular mechanism by which DCLK1 drives the aggressive phenotype of cancer cells is incompletely determined. Methods: Here, we performed comprehensive genomics and proteomics analyses to identify binding proteins of DCLK1 and discovered X-ray repair cross-complementing 5 (XRCC5). Thus, we explored the biological role and downstream events of the DCLK1/XRCC5 axis in human CRC cells and CRC mouse models. Results: The results of comprehensive bioinformatics analyses suggested that DCLK1-driven CRC aggressiveness is linked to inflammation. Mechanistically, DCLK1 bound and phosphorylated XRCC5, which in turn transcriptionally activated cyclooxygenase-2 expression and enhanced prostaglandin E2 production; these events collectively generated the inflammatory tumor microenvironment and enhanced the aggressive behavior of CRC cells. Consistent with the discovered mechanism, inhibition of DCLK1 kinase activity strongly impaired the tumor seeding and growth capabilities in CRC mouse models. Conclusion: Our study illuminates a novel mechanism that mediates the pro-inflammatory function of CSCs in driving the aggressive phenotype of CRC, broadening the biological function of DCLK1 in CRC.


Assuntos
Neoplasias Colorretais , Quinases Semelhantes a Duplacortina , Animais , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Complemento C5/metabolismo , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/metabolismo , Quinases Semelhantes a Duplacortina/metabolismo , Transição Epitelial-Mesenquimal/genética , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Autoantígeno Ku/metabolismo , Camundongos , Células-Tronco Neoplásicas/metabolismo , Proteínas Serina-Treonina Quinases/genética , Microambiente Tumoral/genética , Raios X
7.
Theranostics ; 12(9): 4399-4414, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35673579

RESUMO

Rationale: Dysadherin is a tumor-associated, membrane-embedded antigen found in multiple types of cancer cells, and associated with malignant behavior of cancer cells; however, the fundamental molecular mechanism by which dysadherin drives aggressive phenotypes of cancer is not yet fully determined. Methods: To get a mechanistic insight, we explored the physiological relevance of dysadherin on intestinal tumorigenesis using dysadherin knockout mice and investigated its impact on clinicopathological features in patients with advanced colorectal cancer (CRC). Next, to discover the downstream signaling pathways of dysadherin, we applied bioinformatic analysis using gene expression data of CRC patient tumors and dysadherin knockout cancer cells. Additionally, comprehensive proteomic and molecular analyses were performed to identify dysadherin-interacting proteins and their functions. Results: Dysadherin deficiency suppressed intestinal tumorigenesis in both genetic and chemical mouse models. Moreover, increased dysadherin expression in cancer cells accounted for shorter survival in CRC patients. Comprehensive bioinformatics analyses suggested that the effect of dysadherin deletion is linked to a reduction in the extracellular matrix receptor signaling pathway. Mechanistically, the extracellular domain of dysadherin bound fibronectin and enhanced cancer cell adhesion to fibronectin, facilitating the activation of integrin-mediated mechanotransduction and leading to yes-associated protein 1 activation. Dysadherin-fibronectin interaction promoted cancer cell growth, survival, migration, and invasion, effects collectively mediated the protumor activity of dysadherin. Conclusion: Our results highlight a novel function of dysadherin as a driver of mechanotransduction that stimulates CRC progression, providing a potential therapy strategy for CRC.


Assuntos
Neoplasias Colorretais , Canais Iônicos/metabolismo , Proteínas dos Microfilamentos/metabolismo , Proteínas de Neoplasias , Animais , Carcinogênese/genética , Linhagem Celular Tumoral , Transformação Celular Neoplásica/genética , Neoplasias Colorretais/patologia , Fibronectinas/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Mecanotransdução Celular , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Camundongos , Proteínas dos Microfilamentos/genética , Proteínas de Neoplasias/genética , Proteômica
8.
Proc Natl Acad Sci U S A ; 119(9)2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35217600

RESUMO

An ideal cancer therapeutic strategy involves the selective killing of cancer cells without affecting the surrounding normal cells. However, researchers have failed to develop such methods for achieving selective cancer cell death because of shared features between cancerous and normal cells. In this study, we have developed a therapeutic strategy called the cancer-specific insertions-deletions (InDels) attacker (CINDELA) to selectively induce cancer cell death using the CRISPR-Cas system. CINDELA utilizes a previously unexplored idea of introducing CRISPR-mediated DNA double-strand breaks (DSBs) in a cancer-specific fashion to facilitate specific cell death. In particular, CINDELA targets multiple InDels with CRISPR-Cas9 to produce many DNA DSBs that result in cancer-specific cell death. As a proof of concept, we demonstrate here that CINDELA selectively kills human cancer cell lines, xenograft human tumors in mice, patient-derived glioblastoma, and lung patient-driven xenograft tumors without affecting healthy human cells or altering mouse growth.


Assuntos
Sistemas CRISPR-Cas , Mutação INDEL , Neoplasias/genética , Animais , Morte Celular/genética , Quebras de DNA de Cadeia Dupla , Xenoenxertos , Humanos , Camundongos
9.
Elife ; 102021 12 29.
Artigo em Inglês | MEDLINE | ID: mdl-34964438

RESUMO

Background: Non-alcoholic fatty liver disease (NAFLD) is characterized by excessive lipid accumulation and imbalances in lipid metabolism in the liver. Although nuclear receptors (NRs) play a crucial role in hepatic lipid metabolism, the underlying mechanisms of NR regulation in NAFLD remain largely unclear. Methods: Using network analysis and RNA-seq to determine the correlation between NRs and microRNA in human NAFLD patients, we revealed that MIR20B specifically targets PPARA. MIR20B mimic and anti-MIR20B were administered to human HepG2 and Huh-7 cells and mouse primary hepatocytes as well as high-fat diet (HFD)- or methionine-deficient diet (MCD)-fed mice to verify the specific function of MIR20B in NAFLD. We tested the inhibition of the therapeutic effect of a PPARα agonist, fenofibrate, by Mir20b and the synergic effect of combination of fenofibrate with anti-Mir20b in NAFLD mouse model. Results: We revealed that MIR20B specifically targets PPARA through miRNA regulatory network analysis of nuclear receptor genes in NAFLD. The expression of MIR20B was upregulated in free fatty acid (FA)-treated hepatocytes and the livers of both obesity-induced mice and NAFLD patients. Overexpression of MIR20B significantly increased hepatic lipid accumulation and triglyceride levels. Furthermore, MIR20B significantly reduced FA oxidation and mitochondrial biogenesis by targeting PPARA. In Mir20b-introduced mice, the effect of fenofibrate to ameliorate hepatic steatosis was significantly suppressed. Finally, inhibition of Mir20b significantly increased FA oxidation and uptake, resulting in improved insulin sensitivity and a decrease in NAFLD progression. Moreover, combination of fenofibrate and anti-Mir20b exhibited the synergic effect on improvement of NAFLD in MCD-fed mice. Conclusions: Taken together, our results demonstrate that the novel MIR20B targets PPARA, plays a significant role in hepatic lipid metabolism, and present an opportunity for the development of novel therapeutics for NAFLD. Funding: This research was funded by Korea Mouse Phenotyping Project (2016M3A9D5A01952411), the National Research Foundation of Korea (NRF) grant funded by the Korea government (2020R1F1A1061267, 2018R1A5A1024340, NRF-2021R1I1A2041463, 2020R1I1A1A01074940, 2016M3C9A394589324), and the Future-leading Project Research Fund (1.210034.01) of UNIST.


Assuntos
Fenofibrato/farmacologia , Hipolipemiantes/farmacologia , Metabolismo dos Lipídeos , MicroRNAs/genética , Hepatopatia Gordurosa não Alcoólica/genética , PPAR alfa/genética , Animais , Feminino , Humanos , Masculino , Camundongos , MicroRNAs/metabolismo , Hepatopatia Gordurosa não Alcoólica/fisiopatologia , PPAR alfa/metabolismo
10.
Int J Mol Sci ; 22(24)2021 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-34948208

RESUMO

Recurrence and metastasis remain major obstacles in colorectal cancer (CRC) treatment. Recent studies suggest that a small subpopulation of cells with a self-renewal ability, called cancer stem-like cells (CSCs), promotes recurrence and metastasis in CRC. Unfortunately, no CSC inhibitor has been demonstrated to be more effective than existing chemotherapeutic drugs, resulting in a significant unmet need for effective CRC therapies. In this study, transcriptomic profiling of metastatic tumors from CRC patients revealed significant upregulation in the Wnt pathway and stemness genes. Thus, we examined the therapeutic effect of the small-molecule Wnt inhibitor ICG-001 on cancer stemness and metastasis. The ICG-001 treatment efficiently attenuated self-renewal activity and metastatic potential. Mechanistically, myeloid ecotropic viral insertion site 1 (MEIS1) was identified as a target gene of ICG-001 that is transcriptionally regulated by Wnt signaling. A series of functional analyses revealed that MEIS1 enhanced the CSC behavior and metastatic potential of the CRC cells. Collectively, our findings suggest that ICG-001 efficiently inhibits CRC stemness and metastasis by suppressing MEIS1 expression. These results provide a basis for the further clinical investigation of ICG-001 as a targeted therapy for CSCs, opening a new avenue for the development of novel Wnt inhibitors for the treatment of CRC metastasis.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Neoplasias Colorretais/tratamento farmacológico , Proteína Meis1/metabolismo , Células-Tronco Neoplásicas/efeitos dos fármacos , Pirimidinonas/farmacologia , Bibliotecas de Moléculas Pequenas/farmacologia , Via de Sinalização Wnt/efeitos dos fármacos , Animais , Linhagem Celular Tumoral , Neoplasias Colorretais/metabolismo , Perfilação da Expressão Gênica/métodos , Células HCT116 , Células HT29 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos NOD , Transcrição Gênica/efeitos dos fármacos
11.
Clin Transl Med ; 11(11): e552, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34841679

RESUMO

BACKGROUND: Lipid rafts (LRs), cholesterol-enriched microdomains on cell membranes, are increasingly viewed as signalling platforms governing critical facets of cancer progression. The phenotype of cancer stem-like cells (CSCs) presents significant hurdles for successful cancer treatment, and the expression of several CSC markers is associated with LR integrity. However, LR implications in CSCs remain unclear. METHODS: This study evaluated the biological and molecular functions of LRs in colorectal cancer (CRC) by using an LR-disrupting alkylphospholipid (APL) drug, miltefosine. The mechanistic role of miltefosine in CSC inhibition was examined through normal or tumour intestinal mouse organoid, human CRC cell, CRC xenograft and miltefosine treatment gene expression profile analyses. RESULTS: Miltefosine suppresses CSC populations and their self-renewal activities in CRC cells, a CSC-targeting effect leading to irreversible disruption of tumour-initiating potential in vivo. Mechanistically, miltefosine reduced the expression of a set of genes, leading to stem cell death. Among them, miltefosine transcriptionally inhibited checkpoint kinase 1 (CHEK1), indicating that LR integrity is essential for CHEK1 expression regulation. In isolated CD44high CSCs, we found that CSCs exhibited stronger therapy resistance than non-CSC counterparts by preventing cell death through CHEK1-mediated cell cycle checkpoints. However, inhibition of the LR/CHEK1 axis by miltefosine released cell cycle checkpoints, forcing CSCs to enter inappropriate mitosis with accumulated DNA damage and resulting in catastrophic cell death. CONCLUSION: Our findings underscore the therapeutic potential of LR-targeting APLs for CRC treatment that overcomes the therapy-resistant phenotype of CSCs, highlighting the importance of the LR/CHEK1 axis as a novel mechanism of APLs.


Assuntos
Neoplasias Colorretais/tratamento farmacológico , Microdomínios da Membrana/efeitos dos fármacos , Fosforilcolina/análogos & derivados , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/fisiopatologia , Modelos Animais de Doenças , Camundongos , Fosforilcolina/farmacologia , Fosforilcolina/uso terapêutico
12.
Exp Mol Med ; 53(10): 1602-1611, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34697388

RESUMO

Transcription-replication conflicts lead to DNA damage and genomic instability, which are closely related to human diseases. A major source of these conflicts is the formation of R-loops, which consist of an RNA-DNA hybrid and a displaced single-stranded DNA. Although these structures have been studied, many aspects of R-loop biology and R-loop-mediated genome instability remain unclear. Here, we demonstrate that thyroid hormone receptor-associated protein 3 (Thrap3) plays a critical role in regulating R-loop resolution. In cancer cells, Thrap3 interacts with DEAD-box helicase 5 (DDX5) and localizes to R-loops. Arginine-mediated methylation of DDX5 is required for its interaction with Thrap3, and the Thrap3-DDX5 axis induces the recruitment of 5'-3' exoribonuclease 2 (XRN2) into R-loops. Loss of Thrap3 increases R-loop accumulation and DNA damage. These findings suggest that Thrap3 mediates resistance to cell death by preventing R-loop accumulation in cancer cells.


Assuntos
Estruturas R-Loop , Fatores de Transcrição , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/metabolismo , DNA/genética , Proteínas de Ligação a DNA/metabolismo , Instabilidade Genômica , Humanos , RNA , Fatores de Transcrição/genética
13.
Theranostics ; 11(18): 8755-8770, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34522210

RESUMO

Rationale: Chemoradiation (CRT) is commonly used as an adjuvant or neoadjuvant treatment for colorectal cancer (CRC) patients. However, resistant cells manage to survive and propagate after CRT, increasing the risk of recurrence. Thus, better understanding the mechanism of resistant cancer cells is required to achieve better clinical outcomes. Methods: Here, we explored gene expression profiling of CRC patient tumors to identify therapy resistance genes and discovered that protein tyrosine phosphatase receptor type C (PTPRC), which encodes CD45, was increased in remnant tumor tissues after CRT and correlated with metastasis. Through multiple validations using patient tumors and CRC cell lines, we found for the first time the increase of CD45 expression in CRC (EpCAM+) epithelial cells surviving after CRT. Thus, we investigated the biological role and downstream events of CD45 were explored in human CRC cells and CRC mouse models. Results: Increased CD45 expression in cancer cells in pretreated primary tumors accounts for poor regression and recurrence-free survival in CRT-treated patients. High CD45 expression promotes CRC cell survival upon 5-fluorouracil or radiation treatment, while CD45 depletion sensitizes CRC cells to CRT. Intriguingly, CD45 is preferentially expressed in cancer stem-like cells (CSCs), as determined by spheroid culture and the expression of CSC markers, and is required for the distinct functions of CSCs, such as cancer initiation, repopulation, and metastasis. Mechanistically, CD45 phosphatase activity promotes Wnt transcriptional activity by stabilizing the ß-catenin protein, which collectively enhances stemness and the therapy-resistant phenotype. Conclusions: Our results highlight a novel function of CD45 as a mediator of CRT resistance and provide a potential therapy strategy for CRC therapy.


Assuntos
Neoplasias Colorretais/metabolismo , Antígenos Comuns de Leucócito/genética , Via de Sinalização Wnt/fisiologia , Animais , Linhagem Celular Tumoral , Neoplasias Colorretais/fisiopatologia , Bases de Dados Genéticas , Modelos Animais de Doenças , Resistencia a Medicamentos Antineoplásicos/fisiologia , Expressão Gênica/genética , Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Antígenos Comuns de Leucócito/metabolismo , Antígenos Comuns de Leucócito/fisiologia , Camundongos , Camundongos Nus , Células-Tronco Neoplásicas/metabolismo , Estudos Retrospectivos , Células-Tronco/metabolismo , Transcriptoma/genética
14.
J Ethnopharmacol ; 278: 114238, 2021 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-34048878

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Vernicia fordii (Hemsl.) Airy Shaw (V. fordii) is also known as the tung tree and its leaves and fruit are used as an oriental treatment for dyspepsia, edema, and skin diseases, which are known as diabetic complications. AIM OF THE STUDY: In this study, we aimed to investigate the methanolic extract (VF5) of the leaves of V. fordii as an insulin secretagogue and its probable mechanism and verify the effect in HFD-fed mice. MATERIALS AND METHODS: The insulin secretagogue activity of different doses of VF5 (0.1, 0.3 and 1.0 µg/ml) was assessed using in vitro insulin secretion assay and confirmed the anti-diabetic effect in mice fed HFD for 4 weeks with different doses of VF5 (10, 20 and 50 mg/kg oral) for another 6 weeks. Glbenclamide (30 mg/kg, oral) was used as positive control drug. The possible mechanisms were evaluated by using Gö6983 (10 µM), U73122 (10 µM) and nifedipine (10 µM). The major constituents of VF5 were analyzed by UPLC-QToF-MS and 1H and 13C NMR spectroscopy. RESULTS: UPLC-QToF-MS and NMR spectroscopy analysis indicated that one of the main active components of VF5 was tigliane-diterpene esters. VF5 functioned as an insulin secretagogue and enhanced mitochondria respiration and insulin homeostasis. We confirmed that VF5 preserved the ß-cell and reduced the ß-cell expansion which caused by metabolic stress under HFD. The antidiabetic role of VF5 in HFD fed mice was assessed by glucose tolerance test (GTT) and insulin tolerance test (ITT), fasting plasma insulin level, fasting blood glucose level, AKT signal in peripheral tissue in the absence of toxic effects. Mechanistically, insulinotropic effect of VF5 was mediated by activation of PKCα via intracellular Ca2+ influx and enhanced mitochondria function. CONCLUSION: VF5 exhibits potent insulin secretagogue function and improves insulin sensitivity and protection of pancreatic ß-cells from metabolic stress without toxicity. Taken together, our study suggests that VF5 could be potentially used for treating diabetes and metabolic diseases through improving ß-cell function.


Assuntos
Aleurites/química , Diabetes Mellitus Experimental/tratamento farmacológico , Secreção de Insulina/efeitos dos fármacos , Extratos Vegetais/farmacologia , Animais , Diabetes Mellitus Experimental/fisiopatologia , Relação Dose-Resposta a Droga , Teste de Tolerância a Glucose , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/isolamento & purificação , Hipoglicemiantes/farmacologia , Resistência à Insulina , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Extratos Vegetais/administração & dosagem , Extratos Vegetais/efeitos adversos , Estresse Fisiológico/efeitos dos fármacos
15.
Nucleic Acids Res ; 49(10): 5605-5622, 2021 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-33963872

RESUMO

Proper activation of DNA repair pathways in response to DNA replication stress is critical for maintaining genomic integrity. Due to the complex nature of the replication fork (RF), problems at the RF require multiple proteins, some of which remain unidentified, for resolution. In this study, we identified the N-methyl-D-aspartate receptor synaptonuclear signaling and neuronal migration factor (NSMF) as a key replication stress response factor that is important for ataxia telangiectasia and Rad3-related protein (ATR) activation. NSMF localizes rapidly to stalled RFs and acts as a scaffold to modulate replication protein A (RPA) complex formation with cell division cycle 5-like (CDC5L) and ATR/ATR-interacting protein (ATRIP). Depletion of NSMF compromised phosphorylation and ubiquitination of RPA2 and the ATR signaling cascade, resulting in genomic instability at RFs under DNA replication stress. Consistently, NSMF knockout mice exhibited increased genomic instability and hypersensitivity to genotoxic stress. NSMF deficiency in human and mouse cells also caused increased chromosomal instability. Collectively, these findings demonstrate that NSMF regulates the ATR pathway and the replication stress response network for genome maintenance and cell survival.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Proteínas de Ciclo Celular/metabolismo , Dano ao DNA , Reparo do DNA , Proteínas de Ligação a RNA/metabolismo , Proteína de Replicação A/metabolismo , Fatores de Transcrição/fisiologia , Animais , Replicação do DNA , Células HEK293 , Células HeLa , Humanos , Camundongos , Camundongos Knockout
16.
Int J Mol Sci ; 22(6)2021 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-33802993

RESUMO

Despite advances in the preparation of metal oxide (MO) nanoparticles (NPs) as catalysts for various applications, concerns about the biosafety of these particles remain. In this study, we prepared transition metal-doped cerium oxide (TM@CeO2; TM = Cr, Mn, Fe, Co, or Ni) nanoparticles and investigated the mechanism underlying dopant-dependent toxicity in HaCaT human keratinocytes. We show that doping with Cr or Co but not Fe, Mn, or Ni increased the toxicity of CeO2 NPs in dose- and time-dependent manners and led to apoptotic cell death. Interestingly, while both undoped and transition metal-doped NPs increased intracellular reactive oxygen species (ROS), toxic Cr@CeO2 and Co@CeO2 NPs failed to induce the expression of NRF2 (nuclear factor erythroid 2-related factor 2) as well as its downstream target genes involved in the antioxidant defense system. Moreover, activation of NRF2 transcription was correlated with dynamic changes in H3K4me3 and H3K27me3 at the promoter of NRF2, which was not observed in cells exposed to Cr@CeO2 NPs. Furthermore, exposure to relatively non-toxic Fe@CeO2 NPs, but not the toxic Cr@CeO2 NPs, resulted in increased binding of MLL1 complex, a major histone lysine methylase mediating trimethylation of histone H3 lysine 4, at the NRF2 promoter. Taken together, our findings strongly suggest that failure of cells to respond to oxidative stress is critical for dopant-dependent toxicity of CeO2 NPs and emphasize that careful evaluation of newly developed NPs should be preceded before industrial or biomedical applications.


Assuntos
Cério/toxicidade , Células HaCaT/metabolismo , Histonas/metabolismo , Fator 2 Relacionado a NF-E2/genética , Nanopartículas/toxicidade , Ativação Transcricional/genética , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células HaCaT/efeitos dos fármacos , Humanos , Metilação , Fator 2 Relacionado a NF-E2/metabolismo , Nanopartículas/ultraestrutura , Regiões Promotoras Genéticas/genética , Espécies Reativas de Oxigênio/metabolismo
17.
Theranostics ; 10(20): 9153-9171, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32802184

RESUMO

Background: Cancer-specific ligands have been of great interest as pharmaceutical carriers due to the potential for site-specific delivery. In particular, cancer-specific peptides have many advantages over nanoparticles and antibodies, including high biocompatibility, low immunogenicity, and the formation of nontoxic metabolites. The goal of the present study was the development of a novel cancer-specific ligand. Methods: Cancer-specific peptide ligands were screened using a one-bead-one-compound (OBOC) combinatorial method combined with a multiple-antigen-peptide (MAP) synthesis method. The specificity of the peptide ligands toward cancer cells was tested in vitro using a whole-cell binding assay, flow cytometry, and fluorescence confocal microscopy. The tissue distribution profile and therapeutic efficacy of a paclitaxel (PTX)-conjugated peptide ligand was assessed in vivo using xenograft mouse models. Results: We discovered that AGM-330 specifically bound to cancer cells in vitro and in vivo. Treatment with PTX-conjugated AGM-330 dramatically inhibited cancer cell growth in vitro and in vivo compared to treatment with PTX alone. The results of pull-down assay and LC-MS/MS analyses showed that membrane nucleolin (NCL) was the target protein of AGM-330. Although NCL is known as a nuclear protein, we observed that it was overexpressed on the membranes of cancer cells. In particular, membrane NCL neutralization inhibited growth in cancer cells in vitro. Conclusions: In summary, our findings indicated that NCL-targeting AGM-330 has great potential for use in cancer diagnosis and targeted drug delivery in cancer therapy.


Assuntos
Neoplasias/tratamento farmacológico , Paclitaxel/farmacologia , Peptídeos/metabolismo , Fosfoproteínas/metabolismo , Proteínas de Ligação a RNA/metabolismo , Animais , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cromatografia Líquida/métodos , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Células HCT116 , Células HT29 , Humanos , Células Jurkat , Ligantes , Células MCF-7 , Camundongos , Nanopartículas/uso terapêutico , Neoplasias/metabolismo , Medicina de Precisão/métodos , Espectrometria de Massas em Tandem/métodos , Nucleolina
18.
Nanomaterials (Basel) ; 10(8)2020 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-32781774

RESUMO

We demonstrated that Fe/Cr doped and pH-modified CeO2 nanoparticles (NPs) exhibit enhanced photocatalytic performance as compared to bare CeO2 NPs, using photocatalytic degradation. To assess the toxicity level of these double-modified CeO2 NPs on the human skin, they were introduced into HaCaT cells. The results of our conventional cellular toxicity assays (neutral red uptake and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide for assays) indicated that Cr@CeOx NPs prompt severe negative effects on the viability of human cells. Moreover, the results obtained by scanning transmission X-ray microscopy and bio-transmission electron microscope analysis showed that most of the NPs were localized outside the nucleus of the cells. Thus, serious genetic toxicity was unlikely. Overall, this study highlights the need to prevent the development of Cr@CeOx NP toxicity. Moreover, further research should aim to improve the photocatalytic properties and activity of these NPs while accounting for their stability issues.

19.
Exp Mol Med ; 52(6): 940-950, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32504039

RESUMO

The endoplasmic reticulum (ER) stress response is an adaptive mechanism that is activated upon disruption of ER homeostasis and protects the cells against certain harmful environmental stimuli. However, critical and prolonged cell stress triggers cell death. In this study, we demonstrate that Flightless-1 (FliI) regulates ER stress-induced apoptosis in colon cancer cells by modulating Ca2+ homeostasis. FliI was highly expressed in both colon cell lines and colorectal cancer mouse models. In a mouse xenograft model using CT26 mouse colorectal cancer cells, tumor formation was slowed due to elevated levels of apoptosis in FliI-knockdown (FliI-KD) cells. FliI-KD cells treated with ER stress inducers, thapsigargin (TG), and tunicamycin exhibited activation of the unfolded protein response (UPR) and induction of UPR-related gene expression, which eventually triggered apoptosis. FliI-KD increased the intracellular Ca2+ concentration, and this upregulation was caused by accelerated ER-to-cytosolic efflux of Ca2+. The increase in intracellular Ca2+ concentration was significantly blocked by dantrolene and tetracaine, inhibitors of ryanodine receptors (RyRs). Dantrolene inhibited TG-induced ER stress and decreased the rate of apoptosis in FliI-KD CT26 cells. Finally, we found that knockdown of FliI decreased the levels of sorcin and ER Ca2+ and that TG-induced ER stress was recovered by overexpression of sorcin in FliI-KD cells. Taken together, these results suggest that FliI regulates sorcin expression, which modulates Ca2+ homeostasis in the ER through RyRs. Our findings reveal a novel mechanism by which FliI influences Ca2+ homeostasis and cell survival during ER stress.


Assuntos
Cálcio/metabolismo , Neoplasias Colorretais/metabolismo , Estresse do Retículo Endoplasmático/fisiologia , Proteínas dos Microfilamentos/metabolismo , Transativadores/metabolismo , Animais , Apoptose/genética , Apoptose/fisiologia , Linhagem Celular Tumoral , Sobrevivência Celular/genética , Sobrevivência Celular/fisiologia , Neoplasias Colorretais/genética , Estresse do Retículo Endoplasmático/genética , Humanos , Immunoblotting , Masculino , Camundongos , Proteínas dos Microfilamentos/genética , Transativadores/genética , Ensaios Antitumorais Modelo de Xenoenxerto
20.
Nutrients ; 12(3)2020 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-32183397

RESUMO

: The chronic low-grade inflammation in adipose tissue plays a causal role in obesity-induced insulin resistance and its associated pathophysiological consequences. In this study, we investigated the effects of extracts of Broussonetia papyrifera root bark (PRE) and its bioactive components on inflammation and insulin sensitivity. PRE inhibited TNF-α-induced NF-κB transcriptional activity in the NF-κB luciferase assay and pro-inflammatory genes' expression by blocking phosphorylation of IκB and NF-κB in 3T3-L1 adipocytes, which were mediated by activating AMPK. Ten-week-high fat diet (HFD)-fed C57BL6 male mice treated with PRE had improved glucose intolerance and decreased inflammation in adipose tissue, as indicated by reductions in NF-κB phosphorylation and pro-inflammatory genes' expression. Furthermore, PRE activated AMP-activated protein kinase (AMPK) and reduced lipogenic genes' expression in both adipose tissue and liver. Finally, we identified broussoflavonol B (BF) and kazinol J (KJ) as bioactive constituents to suppress pro-inflammatory responses via activating AMPK in 3T3-L1 adipocytes. Taken together, these results indicate the therapeutic potential of PRE, especially BF or KJ, in metabolic diseases such as obesity and type 2 diabetes.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Tecido Adiposo/metabolismo , Anti-Inflamatórios , Broussonetia/química , Resistência à Insulina , Casca de Planta/química , Extratos Vegetais , Raízes de Plantas/química , Transdução de Sinais/efeitos dos fármacos , Células 3T3-L1 , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patologia , Ativação Enzimática/efeitos dos fármacos , Células HEK293 , Humanos , Masculino , Camundongos , Obesidade/tratamento farmacológico , Obesidade/metabolismo , Obesidade/patologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Células RAW 264.7
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