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1.
Int J Biol Sci ; 17(15): 4459-4473, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34803510

RESUMO

miRNA-223 has been previously reported to play an essential role in hepatic cholesterol homeostasis. However, its role in regulation of biliary cholesterol secretion and gallstone formation remains unknown. Hence, mice with conventional knockout (KO), hepatocyte-specific knockout (ΔHepa) / knockdown (KD) or gain expression of miRNA-223 were included in the study and were subjected to lithogenic diet (LD) for various weeks. The gall bladders and liver tissues were harvested for cholesterol crystal imaging, gallstone mass measurement and molecular analysis. Levels of cholesterol, bile salt, phospholipids, and triglyceride were determined in serum, liver tissues, and bile by enzyme color reactive assays. A 3' UTR reporter gene assay was used to verify the direct target genes for miRNA-223. LD-induced gallstone formation was remarkably accelerated in miRNA-223 KO, ΔHepa, and KD mice with concurrent enhancement in total cholesterol levels in liver tissues and bile. Key biliary cholesterol transporters ABCG5 and ABCG8 were identified as direct targets of miRNA-223. Reversely, AAV-mediated hepatocyte-specific miRNA-223 overexpression prevented gallstone progression with reduced targets expression. Therefore, the present study demonstrates a novel role of miRNA-223 in the gallstone formation by targeting ABCG5 and ABCG8 and elevating miRNA-223 would be a potentially novel approach to overcome the sternness of cholesterol gallstone disease.

2.
Cancer Sci ; 2021 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-34710947

RESUMO

Fusion of RET with different partner genes has been detected in papillary thyroid, lung, colorectal, pancreatic, and breast cancer. Approval of selpercatinib for treatment of lung and thyroid cancer with RET gene mutations or fusions calls for studies to explore RET fusion partners and their eligibility for RET-based targeted therapy. In this study, RET fusion patterns in a large group of Chinese cancer patients covering several cancer types were identified using next-generation sequencing. A total of 44 fusion patterns were identified in the study cohort with KIF5B, CCDC6, and ERC1 being the most common RET fusion partners. Notably, 17 novel fusions were first reported in this study. Prevalence of functional RET fusions was 1.05% in lung cancer, 6.03% in thyroid cancer, 0.39% in colorectal cancer, and less than 0.1% in gastric cancer and hepatocellular carcinoma. Analysis showed a preference for fusion partners in different tumor types, with KIF5B being the common type in lung cancer, CCDC6 in thyroid cancer, and NCOA4 in colorectal cancer. Co-occurrence of EGFR mutations and RET fusions with rare partner genes (rather than KIF5B) in lung cancer patients was correlated with epidermal growth factor receptor-tyrosine kinase inhibitor resistance and could predict response to targeted therapies. Findings from this study provide a guide to clinicians in determining tumors with specific fusion patterns as candidates for RET targeted therapies.

3.
Gastric Cancer ; 24(6): 1342-1354, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34406546

RESUMO

BACKGROUND: Neoadjuvant chemotherapy (NACT) before radical gastrectomy is preferred for locally advanced gastric cancer (GC). However, clinical practices demonstrate that a considerable proportion of GC patients do not benefit from NACT, largely due to the lack of biomarkers for patient selection and prognosis prediction. A recent study revealed that patients with microsatellite instability-high (MSI-H) may be resistant to NACT, however, most tumors in Chinese GC patients (~ 95%) are characterized by microsatellite stability (MSS). Here, we aimed to discover new molecular biomarkers for this larger population. METHODS: We performed whole-exome sequencing on 46 clinical samples (pre- and post-treatment) from 30 stage II/III MSS GC patients whose response to NACT was rigorously defined. Serum tumor markers (TMs), including AFP, CEA, CA199, CA724 and CA242 were measured during the course. RESULTS: High tumor mutation burden (TMB-H) and 19q12 amplification (19q12 +) were positively associated with the NACT response. When TMB and 19q12 amplification were jointly analyzed, those with TMB-H or 19q12 + showed favorable response to NACT (p = 0.035). Further, TMB-H was negatively correlated with ypN stage, lymph node metastasis, and macrophage infiltration. Patients with TMB-H showed better disease-free survival (DFS) than those with TMB-L (P = 0.025, HR = 0.1331), and this was further validated using two larger GC datasets: TCGA-STAD (p = 0.004) and ICGC-CN (p = 0.045). CONCLUSION: The combination of TMB-H and 19q12 + can serve as an early indicator of response to NACT. Superior to traditional clinical indicators, TMB-H is a robust and easily accessible candidate biomarker associated with better DFS, and can be evaluated at the time of diagnosis.

4.
Front Oncol ; 11: 725938, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34422670

RESUMO

Background: Non-small cell lung cancer (NSCLC) is one of the most prevalent causes of cancer-related death worldwide. Recently, there are many important medical advancements on NSCLC, such as therapies based on tyrosine kinase inhibitors and immune checkpoint inhibitors. Most of these therapies require tumor molecular testing for selecting patients who would benefit most from them. As invasive biopsy is highly risky, NSCLC molecular testing based on liquid biopsy has received more and more attention recently. Objective: We aimed to introduce liquid biopsy and its potential clinical applications in NSCLC patients, including cancer diagnosis, treatment plan prioritization, minimal residual disease detection, and dynamic monitoring on the response to cancer treatment. Method: We reviewed recent studies on circulating tumor DNA (ctDNA) testing, which is a minimally invasive approach to identify the presence of tumor-related mutations. In addition, we evaluated potential clinical applications of ctDNA as blood biomarkers for advanced NSCLC patients. Results: Most studies have indicated that ctDNA testing is critical in diagnosing NSCLC, predicting clinical outcomes, monitoring response to targeted therapies and immunotherapies, and detecting cancer recurrence. Moreover, the changes of ctDNA levels are associated with tumor mutation burden and cancer progression. Conclusion: The ctDNA testing is promising in guiding the therapies on NSCLC patients.

5.
Front Oncol ; 11: 675873, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34221994

RESUMO

Combination immunotherapy can overcome the limited objective response rates of PD-1 blockade. Interferon alpha (IFN-α) has been proven to be effective in modulating immune responses and may enhance the clinical responses to PD-1 blockade. According to clinical practice guidelines, IFN-α was recommended as adjuvant therapy for stage IIB/C melanoma patients. However, the impact of prior IFN-α therapy on the efficacy of subsequent PD-1 blockade in melanoma has not been previously reported. Therefore, we performed a retrospective analysis for melanoma patients and addressed whether prior IFN-α therapy enhanced adjuvant pembrolizumab as later-line treatment. Fifty-six patients with resectable stage III/IV melanoma who received adjuvant therapy with pembrolizumab were retrospectively enrolled in this study. Notably, 25 patients received adjuvant pegylated IFN-α (PEG-IFN-α) in the prior line of treatment while 31 patients did not receive prior PEG-IFN-α therapy. Cox regression analysis showed that prior PEG-IFN-α therapy was associated with the efficacy of later-line adjuvant pembrolizumab (hazard ratio=0.37, 95% CI 0.16-0.89; P = 0.026). The recurrence rates after treatment with adjuvant pembrolizumab were significantly reduced in the prior PEG-IFN-α group (P < 0.001). The Kaplan-Meier analysis also showed that recurrence-free survival (RFS) after adjuvant pembrolizumab therapy was prolonged by prior PEG-IFN-α treatment (median RFSPem 8.5 months vs. 4.5 months; P = 0.0372). These findings indicated that prior PEG-IFN-α could enhance the efficacy of adjuvant pembrolizumab. The long-lasting effects of PEG-IFN-α provide a new rationale for designing combination or sequential immunotherapy.

7.
Virus Evol ; 7(1): veab022, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33959381

RESUMO

Trillions of viruses inhabit the gastrointestinal tract. Some of them have been well-studied on their roles in infection and human health, but the majority remains unsurveyed. It has been established that the composition of the gut virome is highly variable based on the changes of diet, physical state, and environmental factors. However, the effect of host genetic factors, for example ethnic origin, on the gut virome is rarely investigated. Here, we characterized and compared the gut virome in a cohort of local Chinese residents and visiting Pakistani individuals, each group containing twenty-four healthy adults and six children. Using metagenomic shotgun sequencing and assembly of fecal samples, a huge number of viral operational taxonomic units (vOTUs) were identified for profiling the DNA and RNA viromes. National background contributed a primary variation to individuals' gut virome. Compared with the Chinese adults, the Pakistan adults showed higher macrodiversity and different compositional and functional structures in their DNA virome and lower diversity and altered composition in their RNA virome. The virome variations of Pakistan children were not only inherited from that of the adults but also tended to share similar characteristics with the Chinese cohort. We also analyzed and compared the bacterial microbiome between two cohorts and further revealed numerous connections between viruses and bacterial host. Statistically, the gut DNA and RNA viromes were covariant to some extent (P < 0.001), and they both correlated the holistic bacterial composition and vice versa. This study provides an overview of the gut viral community in Chinese and visiting Pakistanis and proposes a considerable role of ethnic origin in shaping the virome.

8.
Front Oncol ; 11: 569429, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33912440

RESUMO

Background: Brain metastasis mainly originates from lung cancer. Napsin A and TTF-1 factors have frequently been detected in lung adenocarcinoma cases. Brain metastasis tumors with napsin A and TTF-1 positive are easily classified as lung adenocarcinoma origin. However, some thyroid cancers also exhibit these clinical features. Besides, lung is the most common metastasis of undifferential thyroid cancer. Therefore, it requires development of novel diagnostic tools to aid in distinguishing between pulmonary and thyroid origin. Patient Findings: We reported a case that was initially diagnosed as brain metastatic lung cancer based on immunohistochemistry results. Analysis of next-generation sequencing (NGS) data from the brain lesion revealed that the cancer may have originated from the thyroid. We detected combo mutations in TERT promoter mutation, RET fusion and TP53, which are common in undifferential thyroid cancer (UTC), but rare for lung cancer. These results, coupled with identification of PAX8, indicated that this patient had UTC. Additionally, her three sons, despite being asymptomatic, were all diagnosed with papillary thyroid carcinoma. Summary: The patient received anlotinib treatment and showed good clinical outcomes. One month after anlotinib treatment, the pulmonary nodules were found to be controlled, and the thyroid tumor drastically reduced, and tracheal compression relieved. She continued anlotinib treatment for the following two months, but died one month later because the treatment stopped owing to financial reasons. All her sons underwent total thyroidectomy with lymph node dissection. Conclusions: Although NGS has been reported to assist in diagnosis of the origin of some tumors, this is the first evidence of NGS for the determination of the origin of thyroid tumors. To our knowledge, this is the first time that a combination of multiple mutations has been used to help determine the origin of a tumor, compared with the previous single mutant gene. Moreover, this is the first evidence on the use of anlotinib for treatment of UTC with distant metastasis. Besides, all three sons of the patient had thyroid carcinoma in subsequent examinations, indicating high-risk for familial non-medullary thyroid cancer in UTC patients and necessity for performing thyroid ultrasound testing in other family members.

9.
Free Radic Biol Med ; 168: 247-257, 2021 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-33812997

RESUMO

Methicillin-resistant Staphylococcus aureus (MRSA) is the leading cause of bacterial pneumonia, featured with exuberant inflammatory cytokine production, extensive oxidative stress and tissue injury. The Keap1/Nrf2 system is the major apparatus essential for host defense against oxidative and electrophilic stresses of both exogenous and endogenous origins, representing a logical target for host-directed strategy to treat severe inflammatory diseases including MRSA-induced pneumonia. In an effort to search therapeutics for bacterial pneumonia, we identify rosmarinic acid (RA) as a covalent modifier of Keap1 and hence an activator of Nrf2. Specifically, RA forms a covalent bond with the cysteine 151 of Keap1 in BTB domain, and blocks its association with Nrf2 for proteasome-mediated degradation. Consequently, RA treatment caused the increased Nrf2 nuclear translocation to initiate antioxidant and mitochondrial biogenic programs, as well as macrophage bactericidal activity through inducing autophagic pathway, which eventually led to expedited bacterial eradication, inflammation resolution, and disease recovery. Collectively, our findings establish RA as a specific inducer of Nrf2 and show its potential to prevent MRSA pneumonia.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Pneumonia Bacteriana , Cinamatos , Depsídeos , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch/genética , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo
10.
Artigo em Inglês | MEDLINE | ID: mdl-33759222

RESUMO

Cancer is counted as a second leading cause of death among nontransmissible diseases. Identification of novel anticancer drugs is therefore necessary for the effective treatment of cancer. Conventional drug discovery is time consuming and expensive process. Unlike conventional drug discovery, drug repositioning offers a novel strategy for urgent drug discovery since it is a cost-effective and faster process. Bazedoxifene (BZA) is a synthetic selective estrogen receptor modulator, approved by the United States Food and Drug Administration for the treatment of osteoporosis in postmenopausal women. BZA is now being studied for its anticancer activity in various cancers including breast cancer, liver cancer, pancreatic cancer, colon cancer, head and neck cancer, medulloblastoma, brain cancer, and gastrointestinal cancer. Studies have reported that BZA is effective in reducing cancer progression through multiple mechanisms. BZA could effectively inhibit STAT3, PI3K/AKT, and MAPK signaling pathways and induce apoptosis. In addition to its anticancer activity as monotherapy, BZA has been shown to enhance the chemotherapeutic efficacy of clinical drugs such as paclitaxel, cisplatin, palbociclib, and oxaliplatin in multiple neoplasms. This review mainly focused on the anticancer activity, cellular targets, and anticancer mechanism of BZA, which may help the further design and conduct of research and repositioning it for oncological clinic trials.

11.
Biomed Res Int ; 2021: 1294536, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33490263

RESUMO

[This corrects the article DOI: 10.1155/2019/1851740.].

12.
Phytother Res ; 35(2): 771-789, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32945582

RESUMO

Cancer is one of the most devastating disease and leading cause of death worldwide. The conventional anticancer drugs are monotarget, toxic, expensive and suffer from drug resistance. Development of multi-targeted drugs from natural products has emerged as a new paradigm to overcome aforementioned conventionally encountered obstacles. Hispidulin (HIS), is a biologically active natural flavone with versatile biological and pharmacological activities. The anticancer, antimutagenic, antioxidative and anti-inflammatory properties of HIS have been reported. The aim of this review is to summarize the findings of several studies over the last few decades on the anticancer activity of HIS published in various databases including PubMed, Google Scholar, and Scopus. HIS has been shown to reduce the growth of cancer cells by inducing apoptosis, arresting cell cycle, inhibiting angiogenesis, invasion and metastasis via modulating multiple signaling pathways implicated in cancer initiation and progression. Multitargeted anticancer activity of HIS remains the strongest point for developing it into potential anticancer drug. We also highlighted the natural sources, anticancer mechanism, cellular targets, and chemo-sensitizing potential of HIS. This review will provide bases for design and conduct of further pre-clinical and clinical trials to develop HIS into a lead structure for future anticancer therapy.


Assuntos
Produtos Biológicos/uso terapêutico , Flavonas/uso terapêutico , Neoplasias/tratamento farmacológico , Animais , Produtos Biológicos/farmacologia , Flavonas/farmacologia , Humanos , Camundongos
14.
Front Pharmacol ; 11: 01055, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33013353

RESUMO

Breast cancer is the most heterogenous cancer type among women across the world. Despite concerted efforts, breast cancer management is still unsatisfactory. Interplay between apoptosis and autophagy is an imperative factor in categorizing therapeutics for cancer treatment. Proscillaridin A (PSD-A), a well-known cardiac glycoside used for cardiac arrest and arrythmias, has been unveiled in many cancer types but the underlying mechanism for apoptosis and autophagy in breast cancer is not fully understood. In our study, PSD-A restricted cell growth, inhibited STAT3 activation and induced apoptosis and autophagy in breast cancer cells via ROS generation and Ca+2 oscillation. Pretreatment of NAC and BAPTA-AM restored PSD-A induced cellular events in breast cancer cells. PSD-A induced apoptosis via DNA fragmentation, caspase-cascade activation, PARP cleavage, mitochondrial dysfunction, Bax/Bcl-2 proteins modulation and ER chaperone GRP78 inhibition along with decreased phosphorylation of ERK1/2. Inhibition of STAT3 activation was found to be associated with decreased phosphorylation of SRC. Moreover, PSD-A induced events of autophagy i.e. conversion of LC3-I to LC3-II, and Atg3 expression via JNK activation and decreased mTOR and AKT phosphorylation. In this study, pretreatment of SP600125, a JNK inhibitor, reduced autophagy and enhanced STAT3 inhibition and apoptosis. Additionally, SB203580, a commercial p38 inhibitor, stimulated STAT3 activation and improved autophagic events rate in breast cancer cells, displaying the role of the MAPK signaling pathway in interplay between apoptosis and autophagy. Our data suggest that the rate of apoptotic cell death is improved by blocking JNK-induced autophagy in PSD-A treated MCF-7 and MDA-MB-231 breast cancer cells.

16.
Infect Drug Resist ; 13: 2751-2759, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32884304

RESUMO

Background: Aminoglycosides are one of a few susceptible antimicrobials available for carbapenem-resistant Enterobacteriaceae (CRE). However, the altered pharmacokinetics and increasing drug resistance of aminoglycosides will make them hardly effective if used in monotherapy. The purpose of this study was to identify herbal compounds that potentiate the antibacterial effect of gentamicin against carbapenem-resistant Klebsiella pneumoniae (CRKp) with gentamicin resistance and explore the action mechanisms. Methods: A collection of 280 Chinese herbal compounds was screened for synergistic effect with gentamicin against CRKp by broth microdilution method according to the standard of the Clinical and Laboratory Standards Institute (CLSI). Intracellular gentamicin was measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The membrane potential was evaluated by BacLightTM Bacterial Membrane Potential Kit. Plumbagin-induced metabolite changes of vital metabolic pathways were measured by an optimized untargeted metabolomics method based on gas chromatography-mass spectrometer (GC/MS). Intracellular nicotinamide adenine dinucleotide (NADH) was detected via EnzyChrom NAD/NADH assay kit. Results: We identified plumbagin to remarkably potentiate the antimicrobial activity of gentamicin against the CRKp with gentamicin resistance. Plumbagin at 100 µM could bring the MIC of gentamicin from >16 µg/mL to ~4 µg/mL despite its minimal inhibitory effect on the CRKp. A similar synergistic effect with gentamicin was also observed in an antibiotics-susceptible strain of Klebsiella pneumoniae. Compared with gentamicin monotreatment, the combination group showed a higher intracellular concentration of gentamicin and increased membrane potential in CRKp. Metabolomics analysis indicated remarkable increases of malate and α-ketoglutarate in the tricarboxylic acid (TCA) cycle in the CRKp upon plumbagin treatment. Further analysis revealed higher intracellular NADH concentration in plumbagin-treated CRKp, supporting increased proton-motive force (PMF) that facilitates aminoglycosides uptake. Conclusion: Herbal compound plumbagin was identified to stimulate gentamicin uptake by CRKp via enhancing TCA efflux and PMF to achieve a synergistic antibacterial effect. Plumbagin may be used in combination with aminoglycosides for severe CRKp infection by potentiating their therapeutic efficacy and lowering dosage.

17.
Cancer Med ; 9(22): 8397-8405, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32976686

RESUMO

BACKGROUND: Thyroid nodules are highly prevalent, with fine-needle aspiration (FNA) commonly used as the standard preoperative tool for their diagnosis. However, the method classifies some of the samples as indeterminate, leading to unnecessary surgery. In this study, we evaluated the value of next-generation sequencing (NGS) for cancer diagnosis in indeterminate thyroid nodules. MATERIALS AND METHODS: We performed a prospective, blinded cohort study on 189 patients, with 196 Bethesda III/IV nodules. Specifically, we analyzed DNA mutations and RNA fusions across the FNA samples using NGS, then reviewed follow-up reports from 84 nodules following definitive surgery, to determine the assay performance. RESULTS: Enough DNA and RNA were obtained in 188 nodules, revealing mutations or fusions in 34.6% of them. The most frequently mutated genes were RAS, followed by BRAF V600E. Based on surgical pathology, 39% (33/84) and 4.8% (4/84) of the nodules were malignant and intermediate, respectively. According to the risk stratification criteria, 28 cases were categorized High-Risk group, all of the resected nodules (n = 20) were malignant. Twenty-four thyroid nodules were in the Low-Risk group, 28.6% (4/14) surgically removed nodules were malignant. In the Benign-Like category, 18.0% (9/50) were malignant. Five out of 13 nodules with benign mutations were resected, including SPOP, EZH1, and ZNF148, all of them were benign. If genetic alterations annotated with High-Risk or Low-Risk was considered as positive, and negative if Benign-Like. Multigene testing revealed sensitivity, specificity, positive predictive values (PPV), and negative predictive value (NPV) of 73%, 80%, 71%, and 82%, respectively. In addition, if four intermediate nodules were counted as malignant, the PPV and NPV were 71% and 74%. CONCLUSION: Our results allow for further stratification of Bethesda III/IV thyroid nodules based on the risk of their malignancy. SPOP, EZH1, and ZNF148 mutations may be used as benign markers.


Assuntos
Biomarcadores Tumorais/genética , Perfilação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Neoplasias da Glândula Tireoide/genética , Nódulo da Glândula Tireoide/genética , Transcriptoma , Adulto , Idoso , Pequim , Biópsia por Agulha Fina , Proteínas de Ligação a DNA/genética , Feminino , Fusão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Estadiamento de Neoplasias , Proteínas Nucleares/genética , Complexo Repressor Polycomb 2/genética , Valor Preditivo dos Testes , Estudos Prospectivos , Proteínas Repressoras/genética , Método Simples-Cego , Neoplasias da Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/cirurgia , Nódulo da Glândula Tireoide/patologia , Nódulo da Glândula Tireoide/cirurgia , Tireoidectomia , Fatores de Transcrição/genética , Adulto Jovem
18.
J Am Chem Soc ; 142(37): 15638-15643, 2020 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-32876439

RESUMO

Artificial aquaporins are synthetic molecules that mimic the structure and function of natural aquaporins (AQPs) in cell membranes. The development of artificial aquaporins would provide an alternative strategy for treatment of AQP-related diseases. In this report, an artificial aquaporin has been constructed from an amino-terminated tubular molecule, which operates in a unimolecular mechanism. The artificial channel can work in cell membranes with high water permeability and selectivity rivaling those of AQPs. Importantly, the channel can restore wound healing of the cells that contain function-lost AQPs.


Assuntos
Aquaporinas/farmacologia , Cicatrização/efeitos dos fármacos , Aquaporinas/química , Células Hep G2 , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Modelos Moleculares , Simulação de Dinâmica Molecular , Estrutura Molecular , Imagem Individual de Molécula
19.
Cell Death Dis ; 11(5): 404, 2020 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-32472021

RESUMO

Dysfunction of intestinal epithelial Cl- currents and channels have previously been reported in inflammatory intestinal diseases. However, the expression and function of the newly identified Ca2+-activated Cl- channel transmembrane member 16A (TMEM16A) in the intestinal epithelium is unclear. In this study, we investigated the effects of TMEM16A on intestinal epithelial barrier function in vitro. Intestinal epithelial barrier dysfunction was modeled by lipopolysaccharide (LPS)-induced cell damage in intestinal epithelial IEC-6 cells and the effects of TMEM16A knockdown and overexpression on cell apoptosis and tight junctions were studied. Corresponding mRNA and protein expression levels were measured by quantitative real-time polymerase chain reaction, western blotting, and immunofluorescence analysis, respectively. TMEM16A expression was significantly increased by LPS, possibly via a process involving the transcription factor nuclear factor-κB and both Th1 and Th2 cytokines. Low- and high-dose LPS dysregulated tight junctions (high-myosin light-chain kinase expression) and cell apoptosis-dependent cell barrier dysfunction, respectively. TMEM16A aggravated cell barrier dysfunction in IEC-6 cells pretreated with low-dose LPS by activating ERK1/MLCK signaling pathways, but protected against cell barrier dysfunction by activating ERK/Bcl-2/Bax signaling pathways in IEC-6 cells pretreated with high-dose LPS. We concluded that TMEM16A played a dual role in LPS-induced epithelial dysfunction in vitro. The present results indicated the complex regulatory mechanisms and targeting of TMEM16A may provide potential treatment strategies for intestinal epithelial barrier damage, as well as forming the basis for future studies of the expression and function of TMEM16A in normal and inflammatory intestinal diseases in vivo.


Assuntos
Anoctamina-1/metabolismo , Células Epiteliais/patologia , Intestinos/patologia , Lipopolissacarídeos/toxicidade , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular , Sulfato de Dextrana , Impedância Elétrica , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Masculino , Camundongos Endogâmicos C57BL , RNA Interferente Pequeno/metabolismo , Ratos , Junções Íntimas/efeitos dos fármacos , Junções Íntimas/metabolismo , Ácido Trinitrobenzenossulfônico
20.
J Cancer ; 11(13): 3725-3735, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32328177

RESUMO

Sesquiterpene lactones have been shown to be promising leads for anticancer drug development. Brevilin A (BLN-A), a sesquiterpene lactone compound of Centipeda minima has been shown to exhibit anticancer effects against various cancer cells. However, the anticancer mechanism and cellular targets of BLN-A remain elusive. Here in this study, BLN-A inhibits proliferation and induces cell morphological changes in A549 and NCI-H1650 non-small cell lung cancer cells in a dose-dependent manner. Moreover, BLN-A increased ROS generation and bax/bcl-2 ratio while decreased intracellular glutathione (GSH), and mitochondrial membrane potential which resulted in induction of apoptosis as evident by annexin-V/FITC staining, caspase-3 activation and PARP cleavage. Supplementation of cells with NAC (ROS Scavenger) effectively protected the cells from BLN-A-induced apoptosis. Finally, BLN-A inhibited constitutive as well as IL-6- and EGF-induced STAT3 activation at Tyr705. Using molecular docking and SPR analyses, we found that BLN-A directly binds with STAT3 and thereby inhibits its activation. Knocking down of STAT3 by stable transfection with shRNA suppressed growth and augmented cytotoxicity of BLN-A, indicating the key role of STAT3 in BLN-A-mediated apoptosis. Cumulative findings suggest that BLN-A is a promising lead structure for developing it into a potent STAT3 inhibitor and therapeutic agent against NSCLC as well.

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