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1.
Environ Toxicol ; 39(3): 1505-1520, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37994574

RESUMO

Cytochrome P450 (CYP) 4Z1 (CYP4Z1) has recently garnered much interest as its expression predicts a poor prognosis and as a oncogene in breast cancer, and overexpressed in other many cancers. We previously showed that CYP4Z1 acts as a promoter of cancer stem cells (CSCs) to facilitate the occurrence and development of breast cancer. Here, RNA sequencing found that 1-benzylimidazole (1-Benzy) held a preferable correlation with breast cancer and suppressed the expression of CSC makers. Further functional experiments, including mammary spheroid formation, wound-healing, transwell-invasion, detection of tumor initiation, and metastatic ability, showed that 1-Benzy suppressed the stemness and metastasis of breast cancer cells. Additionally, we further demonstrated that CYP4Z1 is necessary for 1-Benzy-mediated suppression on breast cancer stemness and 1-Benzy exerted a weaker effect in breast cancer cells with CYP4Z1 knockdown. Taken together, our data suggest that 1-Benzy might be a potential drug suppressing breast cancer stemness via targeting CYP4Z1.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/metabolismo , Família 4 do Citocromo P450/genética , Família 4 do Citocromo P450/metabolismo , Sistema Enzimático do Citocromo P-450/genética , Imidazóis , Linhagem Celular Tumoral
2.
Bioorg Chem ; 130: 106268, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36399863

RESUMO

The phytoconstituents of the fraction with hemostatic activity of the 70% aqueous ethanol extract of Ypsilandra thibetica Franch. were investigated. As a result, fourteen previously unreported spirostanol saponins, ypsilandrosides Z1-Z14, and nine known analogues were isolated and characterized by MS, NMR, and chemical methods. Among them, ypsilandrosides Z1-Z4 (1-4) have a rare 12-O-ß-d-glucopyranosyl group, while ypsilandrosides Z5-Z8 (5-8) possess a rare double bond between C-4 and C-5, and a hydroxyl or carbonyl located at the C-6. All isolates were further tested for their hemostatic activity. The results suggested that five spirostanol tetraglycosides show favorable inducing platelet aggregation activities. Among them, ypsilandroside G (16) displayed significant inducing platelet aggregation activity with an EC50 value of 57.17 µM. Furthermore, the preliminary structure-activity relationship of these spirostanol glycosides' hemostatic activity was discussed.


Assuntos
Glicosídeos , Hemostáticos , Melanthiaceae , Espirostanos , Glicosídeos/farmacologia , Glicosídeos/química , Hemostáticos/farmacologia , Espectroscopia de Ressonância Magnética , Melanthiaceae/química , Espirostanos/química
3.
J Infect Dis ; 225(8): 1424-1434, 2022 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-33175129

RESUMO

BACKGROUND: Resistance to major public health insecticides in Côte d'Ivoire has intensified and now threatens the long-term effectiveness of malaria vector control interventions. METHODS: This study evaluated the bioefficacy of conventional and next-generation long-lasting insecticidal nets (LLINs), determined resistance profiles, and characterized molecular and metabolic mechanisms in wild Anopheles coluzzii from Southeast Côte d'Ivoire in 2019. RESULTS: Phenotypic resistance was intense: >25% of mosquitoes survived exposure to 10 times the doses of pyrethroids required to kill susceptible populations. Similarly, the 24-hour mortality rate with deltamethrin-only LLINs was very low and not significantly different from that with an untreated net. Sublethal pyrethroid exposure did not induce significant delayed vector mortality effects 72 hours later. In contrast, LLINs containing the synergist piperonyl butoxide, or new insecticides clothianidin and chlorfenapyr, were highly toxic to A. coluzzii. Pyrethroid-susceptible A. coluzzii were significantly more likely to be infected with malaria, compared with those that survived insecticidal exposure. Pyrethroid resistance was associated with significant overexpression of CYP6P4, CYP6P3, and CYP6Z1. CONCLUSIONS: Study findings raise concerns regarding the operational failure of standard LLINs and support the urgent deployment of vector control interventions incorporating piperonyl butoxide, chlorfenapyr, or clothianidin in areas of high resistance intensity in Côte d'Ivoire.


Assuntos
Anopheles , Mosquiteiros Tratados com Inseticida , Inseticidas , Malária , Piretrinas , Animais , Côte d'Ivoire , Resistência a Inseticidas , Inseticidas/farmacologia , Malária/prevenção & controle , Controle de Mosquitos , Mosquitos Vetores , Butóxido de Piperonila/farmacologia , Piretrinas/farmacologia
4.
Biochem Biophys Res Commun ; 611: 118-125, 2022 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-35525100

RESUMO

Radiation resistance reduces patient survival and is an important challenge in treating lung adenocarcinoma (LUAD). Previous studies have shown that histone H2A variants can affect the radiosensitivity of tumors; however, the main role of histone H2A variants in LUAD remains unclear. Using the TCGA database, we found that histone H2A variant H2A.Z.1 is positively associated with the progression and poor prognosis of LUAD. Colony formation, scratch wound-healing, and transwell assays as well as Western blot were performed to assess the role of H2A.Z.1 in vitro. Results suggested that H2A.Z.1 promoted cell migration and invasion, epithelial-mesenchymal transition, stemness, and radiation resistance in LUAD cells. Targeting H2A.Z.1 in combination with radiation therapy could be a potential therapeutic approach for radiation resistant LUAD.


Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/patologia , Adenocarcinoma de Pulmão/radioterapia , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Transição Epitelial-Mesenquimal/genética , Regulação Neoplásica da Expressão Gênica , Histonas/genética , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/radioterapia
5.
Breast Cancer Res Treat ; 191(2): 319-326, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34725776

RESUMO

PURPOSE: CYP4Z1 is a human cytochrome P450 enzyme involved in breast cancer progression and prognosis, but its functional role in these processes is not understood. In order to gain more insight into CYP4Z1's properties it was recombinantly expressed in a host animal that does not have an endogenous homologue. METHODS: We generated a transgenic mouse model that specifically expresses human CYP4Z1 in breast tissue under the control of the whey acidic protein promoter. Complementary experiments were done using cell lines derived from human breast cell. RESULTS: Induction of CYP4Z1 expression led to reduction of body weight, activity, and birth rates. Histological analysis revealed no evidence for tumor formation. However, a strong increase in estrogen receptor alpha was observed by immunohistochemistry; weaker but significantly increased immunoreactivity was also detected for collagen I and fibronectin. Overexpression of CYP4Z1 in the human breast cancer cell line MCF7 also led to increased ERα expression. Moreover, increased expression of both CYP4Z1 and ERα was observed in MCF-10A normal breast cells upon cocultivation with MCF-7 cells (with or without overexpression of CYP4Z1). CONCLUSION: These data suggest that CYP4Z1 facilitates breast cancer development by induction of ERα expression via an as yet undefined mechanism.


Assuntos
Neoplasias da Mama , Receptor alfa de Estrogênio , Animais , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Família 4 do Citocromo P450/genética , Família 4 do Citocromo P450/metabolismo , Receptor alfa de Estrogênio/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Camundongos Transgênicos , Regulação para Cima
6.
Small ; 18(13): e2106450, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35122466

RESUMO

A detailed understanding of the surface and interface properties of lead halide perovskites is of interest for several applications, in which these materials may be used. To develop this understanding, the study of clean crystalline surfaces can be an important stepping stone. In this work, the surface properties and electronic structure of two different perovskite single crystal compositions (MAPbI3 and Csx FA1- x PbI3 ) are investigated using synchrotron-based soft X-ray photoelectron spectroscopy (PES), molecular dynamics simulations, and density functional theory. The use of synchrotron-based soft X-ray PES enables high surface sensitivity and nondestructive depth-profiling. Core level and valence band spectra of the single crystals are presented. The authors find two carbon 1s contributions at the surface of MAPbI3 and assign these to MA+ ions in an MAI-terminated surface and to MA+ ions below the surface. It is estimated that the surface is predominantly MAI-terminated but up to 30% of the surface can be PbI2 -terminated. The results presented here can serve as reference spectra for photoelectron spectroscopy investigations of technologically relevant polycrystalline thin films, and the findings can be utilized to further optimize the design of device interfaces.

7.
Medicina (Kaunas) ; 58(9)2022 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-36143940

RESUMO

Background and Objective: Ovarian cancer is a leading cause of death in females. Since its treatment is challenging and causes severe side effects, novel therapies are urgently needed. One of the potential enzymes implicated in the progression of cancers is Cytochrome 4Z1 (CYP4Z1). Its expression in ovarian cancer remains unknown. Therefore, the current study aims to assess CYP4Z1 expression in different subtypes of ovarian cancers. Materials and Methods: Immunohistochemistry was used to characterize CYP4Z1 expression in 192 cases of ovarian cancers along with eight normal ovarian tissues. The enzyme's association with various clinicopathological characteristics and survival was determined. Results: CYP4Z1 was strongly expressed in 79% of ovarian cancers, compared to negative expression in normal ovarian samples. Importantly, significantly high CYP4Z1 expres-sion was determined in patients with advanced-stage cancer and a high depth of invasion (p < 0.05). Surprisingly, CYP4Z1 expression was significantly associated with a low patient survival rate. Univariate analysis revealed that patient survival was strongly associated with CYP4Z1 expression, tumor stage, depth of invasion, and lymph node metastasis (p < 0.05). Multivariate analysis showed that only CYP4Z1 expression was significantly associated with patient survival (p < 0.05). Conclusions: CYP4Z1 expression is correlated with shorter patient survival and has been identified as an independent indicator of a poor prognosis for ovarian cancer patients.


Assuntos
Neoplasias Ovarianas , Família 4 do Citocromo P450/química , Família 4 do Citocromo P450/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Neoplasias Ovarianas/patologia , Prognóstico
8.
J Biol Chem ; 295(4): 955-968, 2020 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-31822561

RESUMO

Perineuronal nets (PNNs) are conspicuous neuron-specific substructures within the extracellular matrix of the central nervous system that have generated an explosion of interest over the last decade. These reticulated structures appear to surround synapses on the cell bodies of a subset of the neurons in the central nervous system and play key roles in both developmental and adult-brain plasticity. Despite the interest in these structures and compelling demonstrations of their importance in regulating plasticity, their precise functional mechanisms remain elusive. The limited mechanistic understanding of PNNs is primarily because of an incomplete knowledge of their molecular composition and structure and a failure to identify PNN-specific targets. Thus, it has been challenging to precisely manipulate PNNs to rigorously investigate their function. Here, using mouse models and neuronal cultures, we demonstrate a role of receptor protein tyrosine phosphatase zeta (RPTPζ) in PNN structure. We found that in the absence of RPTPζ, the reticular structure of PNNs is lost and phenocopies the PNN structural abnormalities observed in tenascin-R knockout brains. Furthermore, we biochemically analyzed the contribution of RPTPζ to PNN formation and structure, which enabled us to generate a more detailed model for PNNs. We provide evidence for two distinct kinds of interactions of PNN components with the neuronal surface, one dependent on RPTPζ and the other requiring the glycosaminoglycan hyaluronan. We propose that these findings offer important insight into PNN structure and lay important groundwork for future strategies to specifically disrupt PNNs to precisely dissect their function.


Assuntos
Matriz Extracelular/metabolismo , Neurônios/metabolismo , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/metabolismo , Agrecanas/metabolismo , Animais , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Ácido Edético/farmacologia , Matriz Extracelular/efeitos dos fármacos , Heterozigoto , Ácido Hialurônico/farmacologia , Proteínas Imobilizadas/metabolismo , Camundongos Knockout , Modelos Biológicos , Neurônios/efeitos dos fármacos , Ligação Proteica/efeitos dos fármacos , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/deficiência , Tenascina/metabolismo
9.
Mol Carcinog ; 60(6): 413-426, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33866606

RESUMO

Ours and other previous studies have shown that CYP4Z1 is specifically and highly expressed in breast cancer, and acts as a promoter for the stemness of breast cancer cells. Here, we explored whether targeting CYP4Z1 could attenuate the stemness of breast cancer cells using HET0016, which has been confirmed to be an inhibitor of CYP4Z1 by us and others. Using the transcriptome-sequencing analysis, we found that HET0016 suppressed the expression of cancer stem cell (CSC) markers and stem cell functions. Additionally, HET0016 indeed reduced the stemness of breast cancer cells, as evident by the decrease of stemness marker expression, CD44+ /CD24- subpopulation with stemness, mammary-spheroid formation, and tumor-initiating ability. Moreover, HET0016 suppressed the metastatic capability through in vitro and in vivo experiments. Furthermore, we confirmed that HET0016 suppressed CYP4Z1 activity, and HET0016-induced inhibition on the stemness and metastasis of breast cancer cells was rescued by CYP4Z1 overexpression. Thus, our results demonstrate that HET0016 can attenuate the stemness of breast cancer cells through targeting CYP4Z1.


Assuntos
Amidinas/farmacologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Família 4 do Citocromo P450/genética , Células-Tronco Neoplásicas/efeitos dos fármacos , Amidinas/administração & dosagem , Animais , Antinematódeos/administração & dosagem , Antinematódeos/farmacologia , Linhagem Celular Tumoral , Família 4 do Citocromo P450/antagonistas & inibidores , Relação Dose-Resposta a Droga , Feminino , Humanos , Camundongos Endogâmicos BALB C , Células-Tronco Neoplásicas/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
10.
Xenobiotica ; 51(8): 901-915, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33993844

RESUMO

8-[(1H-1,2,3-benzotriazol-1-yl)amino]octanoic acid (8-BOA) was recently identified as a selective and potent mechanism-based inactivator (MBI) of breast cancer-associated CYP4Z1 and exhibited favourable inhibitory activity in vitro, thus meriting in vivo characterization.The pharmacokinetics and metabolism of 8-BOA in rats was examined after a single IV bolus dose of 10 mg/kg. A biphasic time-concentration profile resulted in relatively low clearance and a prolonged elimination half-life.The major circulating metabolites identified in plasma were products of ß-oxidation; congeners losing two and four methylene groups accounted for >50% of metabolites by peak area. The -(CH2)2 product was characterized previously as a CYP4Z1 MBI and so represents an active metabolite that may contribute to the desired pharmacological effect.Ex vivo analysis of total CYP content in rat liver and kidney microsomes showed that off-target CYP inactivation was minimal; liver microsomal probe substrate metabolism also demonstrated low off-target inactivation. Standard clinical chemistries provided no indication of acute toxicity.In silico simulations using the free concentration of 8-BOA in plasma suggested that the in vivo dose used here may effectively inactivate CYP4Z1 in a xenografted tumour.


Assuntos
Sistema Enzimático do Citocromo P-450 , Microssomos Hepáticos , Animais , Caprilatos/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Família 4 do Citocromo P450/metabolismo , Humanos , Microssomos Hepáticos/metabolismo , Oxirredução , Ratos
11.
Toxicol Ind Health ; 36(5): 305-309, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32546109

RESUMO

(Z)-1-Chloro-2,3,3,3-tetrafluoropropene (HCFO-1224yd(Z)) is a colorless gas used as a single substance or in a mixture with other substances for refrigeration. The 4-h rat inhalation LC50 values from two studies were reported to be >20,180 ppm and >213,100 ppm. HCFO-1224yd(Z) is not expected to undergo significant metabolism. The no-observed-effect level of HCFO-1224yd(Z) for cardiac sensitization (in dogs) was 75,000 ppm. In a 5-day repeat inhalation study in rats, the only observation noted was repetitive movement of the mouth/jaws in some animals in the 50,000-ppm exposure group for 1-2 days during the first 3 exposure days. The toxicological significance of this observation was unknown; therefore, the study no-observed-adverse-effect level (NOAEL) was established at 50,000 ppm. In a good laboratory practice (GLP)-compliant, 4-week inhalation study in rats, there were no test substance-related adverse effects noted at any exposure concentration. The study NOAEL was established at 40,000 ppm. In a GLP-compliant inhalation developmental toxicity study, female rats were exposed for 6 h/day from gestation day 6 through 19. There were no test substance-related adverse effects on either the maternal or fetal rats at any exposure concentration. The NOAEL for developmental effects was established at 20,000 ppm. There are no chronic toxicity or carcinogenicity studies available. HCFO-1224yd(Z) gave mixed results in in vitro genotoxicity assays but was negative in an in vivo micronucleus assay. The NOAEL of 40,000 ppm for HCFO-1224yd(Z) from the 4-week, GLP-compliant inhalation study in rats was used at the point of departure (POD) for workplace environmental exposure level (WEEL) value development. This POD was adjusted to account for interindividual variability, duration of exposure, and database limitations. The resulting 8-h time-weighted average WEEL value of 1000 ppm is expected to provide a significant margin of safety against any potential adverse health effects in workers exposed to HCFO-1224yd(Z).


Assuntos
Fluorocarbonos/toxicidade , Animais , Cães , Exposição Ambiental/efeitos adversos , Feminino , Fluorocarbonos/química , Fluorocarbonos/farmacocinética , Coração/efeitos dos fármacos , Masculino , Nível de Efeito Adverso não Observado , Gravidez , Ratos
12.
BMC Genomics ; 20(1): 873, 2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31744473

RESUMO

BACKGROUND: Candida albicans is an opportunistic pathogen which is responsible for widespread nosocomial infections. It encompasses a fungus specific serine/threonine protein phosphatase gene, CaPPZ1 that is involved in cation transport, cell wall integrity, oxidative stress response, morphological transition, and virulence according to the phenotypes of the cappz1 deletion mutant. RESULTS: We demonstrated that a short-term treatment with a sublethal concentration of tert-butyl hydroperoxide suppressed the growth of the fungal cells without affecting their viability, both in the cappz1 mutant and in the genetically matching QMY23 control strains. To reveal the gene expression changes behind the above observations we carried out a global transcriptome analysis. We used a pilot DNA microarray hybridization together with extensive RNA sequencing, and confirmed our results by quantitative RT-PCR. Novel functions of the CaPpz1 enzyme and oxidative stress mechanisms have been unraveled. The numbers of genes affected as well as the amplitudes of the transcript level changes indicated that the deletion of the phosphatase sensitized the response of C. albicans to oxidative stress conditions in important physiological functions like membrane transport, cell surface interactions, oxidation-reduction processes, translation and RNA metabolism. CONCLUSIONS: We conclude that in the wild type C. albicans CaPPZ1 has a protective role against oxidative damage. We suggest that the specific inhibition of this phosphatase combined with mild oxidative treatment could be a feasible approach to topical antifungal therapy.


Assuntos
Candida albicans/genética , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica , Estresse Oxidativo/genética , Fosfoproteínas Fosfatases/genética , Transcriptoma , Transporte Biológico , Candida albicans/efeitos dos fármacos , Candida albicans/enzimologia , Proteínas Fúngicas/metabolismo , Deleção de Genes , Perfilação da Expressão Gênica , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Fosfoproteínas Fosfatases/deficiência , Biossíntese de Proteínas , terc-Butil Hidroperóxido/farmacologia
13.
Int J Mol Sci ; 20(21)2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31652755

RESUMO

Variation in the location of the 15p region D15Z1 is recognized as a polymorphism in several human populations. We used high-stringency Fluorescence In Situ Hybridization (FISH) to detect D15Z1 in a Mexican cohort. Here, we report the presence of extra D15Z1 sequences on the p-arm of acrocentric chromosomes other than 15 in two groups of Mexican couples, one with healthy offspring (n = 75) and the other with aneuploid offspring (n = 87), mainly trisomy 21. The additional D15Z1 polymorphism was significantly increased in individuals with aneuploid offspring (26.4%), in comparison to individuals with healthy offspring (14%). The most frequent acceptor chromosome of D15Z1 was chromosome 13p, followed by 14p, and finally, 21p. Our results show an overall frequency of 21.6% of this polymorphism in the Mexican population and suggest that its presence might be associated with the mis-segregation of other acrocentric chromosomes and aneuploid offspring. The high frequency of the polymorphism of the D15Z1 sequence on acrocentric chromosomes other than 15 suggests a sequence homogenization of the acrocentric p arms, related to the important function of the centromere and the nucleolar organization region, which flank satellite III DNA.


Assuntos
Aneuploidia , Cromossomos Humanos Par 15/genética , Polimorfismo Genético , Adulto , Feminino , Humanos , Masculino , México , Linhagem
14.
Chemphyschem ; 19(2): 169-174, 2018 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-29206333

RESUMO

In this paper we remind the reader of a simple, intuitive picture of chemical shifts in X-ray photoelectron spectroscopy (XPS) as the difference in chemical bonding between the probed atom and its neighbor to the right in the periodic table, the so called Z+1 approximation. We use the classical ESCA molecule, ethyl trifluoroacetate, and 4d-transition metals to explicitly demonstrate agreement between core-level shifts computed as differences between final core-hole states and the approach where each core-ionized atom is replaced by a Z+1 atom. In this final state, or total energy picture, the XPS shift arises due to the more or less unfavorable chemical bonding of the effective nitrogen in the carbon geometry for the ESCA molecule. Surface core level shifts in metals are determined by whether the Z+1 atom as an alloy segregates to the surface or is more soluble in the bulk. As further illustration of this more chemical picture, we compare the geometry of C 1s and O 1s core-ionized CO with that of, respectively, NO+ and CF+ . The scope is not to propose a new method to compute XPS shifts but rather to stress the validity of this simple interpretation.

15.
Cell Commun Signal ; 16(1): 92, 2018 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-30497491

RESUMO

BACKGROUND: Chemotherapy is the primary established systemic treatment for patients with breast cancer, especially those with the triple-negative subtype. Simultaneously, the resistance of triple-negative breast cancer (TNBC) to chemotherapy remains a major clinical problem. Our previous study demonstrated that the expression levels of PTN and its receptor PTPRZ1 were upregulated in recurrent TNBC tissue after chemotherapy, and this increase was closely related to poor prognosis in those patients. However, the mechanism and function of chemotherapy-driven increases in PTN/PTPRZ1 expression are still unclear. METHODS: We compared the expression of PTN and PTPRZ1 between normal breast and cancer tissues as well as before and after chemotherapy in cancer tissue using the microarray analysis data from the GEPIA database and GEO database. The role of chemotherapy-driven increases in PTN/PTPRZ1 expression was examined with a CCK-8 assay, colony formation efficiency assay and apoptosis analysis with TNBC cells. The potential upstream pathways involved in the chemotherapy-driven increases in PTN/PTPRZ1 expression in TNBC cells were explored using microarray analysis, and the downstream mechanism was dissected with siRNA. RESULTS: We demonstrated that the expression of PTN and PTPRZ1 was upregulated by chemotherapy, and this change in expression decreased chemosensitivity by promoting tumour proliferation and inhibiting apoptosis. CDKN1A was the critical switch that regulated the expression of PTN/PTPRZ1 in TNBC cells receiving chemotherapy. We further demonstrated that the mechanism of chemoresistance by chemotherapy-driven increases in the CDKN1A/PTN/PTPRZ1 axis depended on the NF-κB pathway. CONCLUSIONS: Our studies indicated that chemotherapy-driven increases in the CDKN1A/PTN/PTPRZ1 axis play a critical role in chemoresistance, which suggests a novel strategy to enhance chemosensitivity in breast cancer cells, especially in those of the triple-negative subtype.


Assuntos
Proteínas de Transporte/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Citocinas/metabolismo , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , NF-kappa B/metabolismo , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/metabolismo , Transdução de Sinais/efeitos dos fármacos , Neoplasias de Mama Triplo Negativas/patologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Retroalimentação Fisiológica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos
16.
Artigo em Inglês | MEDLINE | ID: mdl-30220828

RESUMO

In this paper we present design, construction, and preliminary results of a proof-of-concept prototype of high-temperature superconductor (HTS) shim coils operated at 77 K and energized, for the first time among all shim coils, by a flux pump, here called digital flux injector (DFI). Although the prototype shims were wound with 2-mm wide REBCO tape, and DFI with Bi2223 and REBCO tapes, the HTS Z1 and Z2 shims to be installed in the MIT 1.3-GHz LTS/HTS NMR magnet (1.3G) currently under construction and operated at 4.2 K will be wound with reinforced Bi2212 wire and DFI with Nb3Sn tape. The paper concludes with two sets of Bi2212 Z1 and Z2 shims for 1.3G.

17.
Protein Expr Purif ; 140: 74-80, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28811266

RESUMO

Telethonin anchors the N-terminal region of titin in the Z-disk of the sarcomere by binding to two immunoglobulin-like (Ig) domains (Z1 and Z2) of titin (Z1Z2). Thereby telethonin plays an important role in myofibril assembly and in muscle development and functional regulation. The expression and purification of recombinant telethonin is very challenging. In previous studies, recombinant telethonin expressed from E. coli was refolded in the presence of Z1Z2. Here, we report various strategies to establish a reliable and efficient protocol for the preparation of telethonin and titin Z1Z2 protein. First, a co-expression strategy was designed to obtain soluble Z1Z2/telethonin complexes. The concentration of antibiotics and the type of expression vector were found to be important for achieving high yields of purified complex. Second, the five cysteine residues of telethonin were mutated to serine to avoid severe problems with cysteine oxidation. Third, a short version of telethonin (telethonin1-90) was designed to avoid the proteolytic degradation observed for longer constructs of the protein. The short telethonin formed a highly stable complex with Z1Z2 with no degradation being observed for 30 days at 4 °C. Fourth, an improved refolding protocol was developed to achieve high yields of Z1Z2/telethonin complex. Finally, based on the crystal structure in which Z1Z2 and telethonin1-90 assemble into a 2:1 complex, a single chain fusion protein was designed, comprising two Z1Z2 modules that are connected by flexible linkers N- and C-terminally of the telethonin1-90. Expression of this fusion protein, named ZTZ, affords high yields of soluble expressed and purified protein.


Assuntos
Conectina/isolamento & purificação , Complexos Multiproteicos/isolamento & purificação , Proteínas Recombinantes/isolamento & purificação , Conectina/biossíntese , Conectina/química , Conectina/genética , Escherichia coli/genética , Humanos , Complexos Multiproteicos/química , Complexos Multiproteicos/genética , Proteínas Musculares/química , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Sarcômeros/química , Sarcômeros/genética
18.
Biochem Biophys Res Commun ; 478(2): 900-7, 2016 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-27520371

RESUMO

To investigate the effects of CYP4Z1 3'UTR in migration of breast cancer cells, a series of assays were used to confirm that overexpression of CYP4Z1 3'UTR could suppress the capacity of migration and adhesion of MCF-7 and MDA-MB-231 cells. EMT (Epithelial-mesenchymal transition)-related proteins were regulated by CYP4Z1 3'UTR. Mesenchyma markers like Vimentin, MMP-2, and MMP-9 were down-regulated, while the expression of E-cadherin was up-regulated with CYP4Z1 3'UTR overexpression. Notably, luciferase reporter and qRT-PCR assays were applied to verify that CYP4Z1 3'UTR was the potential target of miR-9. In addition, our results showed that CYP4Z1 3'UTR repressed the expression of E-cadherin in a miRNA-dependent manner. Combining with our previous study, we have discovered the underlying link between CYP4Z1 and E-cadherin. Therefore, those preliminary data suggest that CYP4Z1 3'UTR could inhibit the migration and EMT of breast cancer cells via acting as a ceRNA for E-cadherin.


Assuntos
Regiões 3' não Traduzidas/genética , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Movimento Celular/genética , Família 4 do Citocromo P450/genética , Antígenos CD , Caderinas , Adesão Celular , Linhagem Celular Tumoral , Família 4 do Citocromo P450/metabolismo , Transição Epitelial-Mesenquimal/genética , Feminino , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Interferente Pequeno/metabolismo , Transfecção
19.
Mol Ecol ; 25(14): 3436-52, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27135886

RESUMO

Carbamates are increasingly used for vector control notably in areas with pyrethroid resistance. However, a cross-resistance between these insecticides in major malaria vectors such as Anopheles funestus could severely limit available resistance management options. Unfortunately, the molecular basis of such cross-resistance remains uncharacterized in An. funestus, preventing effective resistance management. Here, using a genomewide transcription profiling, we revealed that metabolic resistance through upregulation of cytochrome P450 genes is driving carbamate resistance. The P450s CYP6P9a, CYP6P9b and CYP6Z1 were the most upregulated detoxification genes in the multiple resistant mosquitoes. However, in silico docking simulations predicted CYP6Z1 to metabolize both pyrethroids and carbamates, whereas CYP6P9a and CYP6P9b were predicted to metabolize only the pyrethroids. Using recombinant enzyme metabolism and inhibition assays, we demonstrated that CYP6Z1 metabolizes bendiocarb and pyrethroids, whereas CYP6P9a and CYP6P9b metabolize only the pyrethroids. Other upregulated gene families in resistant mosquitoes included several cuticular protein genes suggesting a possible reduced penetration resistance mechanism. Investigation of the target-site resistance in acetylcholinesterase 1 (ace-1) gene detected and established the association between the new N485I mutation and bendiocarb resistance (odds ratio 7.3; P < 0.0001). The detection of multiple haplotypes in single mosquitoes after cloning suggested the duplication of ace-1. A TaqMan genotyping of the N485I in nine countries revealed that the mutation is located only in southern Africa with frequency of 10-15% suggesting its recent occurrence. These findings will help in monitoring the spread and evolution of carbamate resistance and improve the design of effective resistance management strategies to control this malaria vector.


Assuntos
Acetilcolinesterase/genética , Anopheles/genética , Sistema Enzimático do Citocromo P-450/genética , Resistência a Inseticidas/genética , África Austral , Animais , Análise Mutacional de DNA , Perfilação da Expressão Gênica , Genes de Insetos , Genótipo , Haplótipos , Insetos Vetores/genética , Inseticidas , Simulação de Acoplamento Molecular , Mutação , Fenilcarbamatos , Piretrinas
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