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1.
Chemistry ; 30(12): e202303753, 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38215247

RESUMO

The enzyme-resistant thioglycosides are highly valuable immunogens because of their enhanced metabolic stability. We report the first synthesis of a family of thiooligosaccharides related to the capsular polysaccharides (CPS) of Campylobacter jejuni HS:4 for potential use in conjugate vaccines. The native CPS structures of the pathogen consist of a challenging repeating disaccharide formed with ß(1→4)-linked 6-deoxy-ß-D-ido-heptopyranoside and N-acetyl-D-glucosamine; the rare 6-deoxy-ido-heptopyranosyl backbone and ß-anomeric configuration of the former monosaccharide makes the synthesis of this family of antigens very challenging. So far, no synthesis of the thioanalogs of the CPS antigens have been reported. The unprecedented synthesis presented in this work is built on an elegant approach by using ß-glycosylthiolate as a glycosyl donor to open the 2,3-epoxide functionality of pre-designed 6-deoxy-ß-D-talo-heptopyranosides. Our results illustrated that this key trans-thioglycosylation can be designed in a modular and regio and stereo-selective manner. Built on the success of this novel approach, we succeeded the synthesis of a family of thiooligosaccharides including a thiohexasaccharide which is considered to be the desired antigen length and complexity for immunizations. We also report the first direct conversion of base-stable but acid-labile 2-trimethylsilylethyl glycosides to glycosyl-1-thioacetates in a one-pot manner.


Assuntos
Campylobacter jejuni , Polissacarídeos , Polissacarídeos/química , Oligossacarídeos , Dissacarídeos , Polissacarídeos Bacterianos/química
2.
J Biol Inorg Chem ; 28(8): 805-811, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37981582

RESUMO

In the search for improved and safer gadolinium-based magnetic resonance imaging (MRI) contrast agents, macrocyclic cyclodextrins (CDs) attract great interest. Our group previously synthesized a cyclodextrin-based ligand with 1,2,3-triazolmethyl residues conjugated to ß-CD, called ß-CD(A), which efficiently chelates Gd(III) ions. To probe the local structure around the Gd(III) ion in the 1:1 Gd(III): ß-CD(A) complex in aqueous solution (pH 5.5), we used extended X-ray absorption fine structure (EXAFS) spectroscopy. Least-squares curve fitting of the Gd L3-edge EXAFS spectrum revealed 5 Gd-O (4 COO- and 1 H2O) and 4 Gd-N (from two imino and two 1,2,3-triazole groups) bonds around the Gd(III) ion with average distances 2.36 and 2.56 ± 0.02 Å, respectively. A similar EXAFS spectrum was obtained from an aqueous solution of the clinically used MRI contrast agent Na[Gd(DOTA)(H2O)], also 9-coordinated in its first shell. Careful analysis revealed that the mean Gd-N distance is shorter in the Gd(III): ß-CD(A) (1:1) complex, indicating stronger Gd-N bonding and stronger Gd(III) complex formation than with the DOTA4- ligand. This is consistent with the lower free Gd3+ concentration found previously for the Gd(III): ß-CD(A) (1:1) complex than for the [Gd(DOTA)(H2O)]- complex, and shows its potential as an MRI probe. EXAFS spectroscopy revealed a similar Gd(III) 9-coordination although slightly stronger for a modified ß-cyclodextrin: Gd(III) 1:1 complex, [Gd(LH4)]7-, in aqueous solution than for the clinically used MRI contrast agent Na[Gd(DOTA)(H2O)].


Assuntos
Ciclodextrinas , beta-Ciclodextrinas , Gadolínio/química , Meios de Contraste , Ligantes , Imageamento por Ressonância Magnética/métodos
3.
Anal Chim Acta ; 1279: 341815, 2023 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-37827620

RESUMO

Tumor selective near-infrared (NIR) fluorescent contrast agents has the potential to greatly enhance the efficiency and precision of tumor surgery by enabling real-time tumor margin identification for tumor resection guided by imaging. However, the development of these agents is still challenging. In this study, based on the acidic tumor microenvironment (TME), we designed and synthesized a novel pH-sensitive NIR fluorescent contrast agent OBD from ß-carboline. The fluorescence quantum yield of OBD exhibited a notable increase at pH 3.6, approximately 12-fold higher compared to its value at pH 7.4. After cellular uptake, OBD lighted up the cancer cells with high specificity and accumulated in the mitochondria. Spraying OBD emitted selective fluorescence in xenograft tumor tissues with tumor-to-normal tissue ratios (TNR) as high as 11.18, implying successful image-guided surgery. Furthermore, OBD was also shown to track metastasis in spray mode. After simple topical spray, OBD rapidly and precisely visualized the tumor margins of clinical colon and liver tissues with TNR over 4.2. Therefore, the small-molecule fluorescent contrast agent OBD has promising clinical applications in tumor identification during surgery.


Assuntos
Meios de Contraste , Neoplasias , Humanos , Microambiente Tumoral , Neoplasias/diagnóstico por imagem , Corantes Fluorescentes/química , Fluorescência , Imagem Óptica/métodos
4.
Neurobiol Dis ; 186: 106282, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37683956

RESUMO

Stroke is the second leading cause of death worldwide and has two major subtypes: ischemic stroke and hemorrhagic stroke. Neuroinflammation is a pathological hallmark of ischemic stroke and intracerebral hemorrhage (ICH), contributing to the extent of brain injury but also in its repair. Neuroinflammation is intricately linked to the extracellular matrix (ECM), which is profoundly altered after brain injury and in aging. In the early stages after ischemic stroke and ICH, immune cells are involved in the deposition and remodeling of the ECM thereby affecting processes such as blood-brain barrier and cellular integrity. ECM components regulate leukocyte infiltration into the central nervous system, activate a variety of immune cells, and induce the elevation of matrix metalloproteinases (MMPs) after stroke. In turn, excessive MMPs may degrade ECM into components that are pro-inflammatory and injurious. Conversely, in the later stages after stroke, several ECM molecules may contribute to tissue recovery. For example, thrombospondin-1 and biglycan may promote activity of regulatory T cells, inhibit the synthesis of proinflammatory cytokines, and aid regenerative processes. We highlight these roles of the ECM in ischemic stroke and ICH and discuss their potential cellular and molecular mechanisms. Finally, we discuss therapeutics that could be considered to normalize the ECM in stroke. Our goal is to spur research on the ECM in order to improve the prognosis of ischemic stroke and ICH.


Assuntos
Lesões Encefálicas , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Doenças Neuroinflamatórias , Hemorragia Cerebral , Matriz Extracelular
5.
Theranostics ; 13(13): 4497-4511, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37649597

RESUMO

Rationale: Challenges such as developing a universal tumor-specific probe for tumor margin identification in diverse tumors with an easy-operative and fast-imaging pattern still exist. Hence, in the present study, a rapidly "off-on" near-infrared (NIR) fluorescent probe NBD with pH-activatable fluorescence and a large Stokes shift was constructed for spray mediated near-instant and precise clinical tumor margins identification. Methods: NBD was designed and synthesized by introducing both diphenyl amino group and benzo[e]indolium to ß-carboline at C-6 and C-3 positions respectively. The optical properties of NBD was characterized by absorption spectra, fluorescence spectra. Subsequently, we investigated its pH-dependent mechanism by 1H NMR and density functional theory (DFT) calculation. NBD was further under deeper investigation into its imaging performance in nude mice models (subcutaneous, orthotopic, metastatic tumor), and clinical tissues from patients with three clinically representative tumors (liver cancer, colon cancer, and lung cancer). Results: It was found that NBD had NIR fluorescence (742 nm), a large Stokes shift (160 nm), and two-photon absorbance (1040 nm). Fluorescence quantum yield (ФF) increased by 5.5-fold when pH decreased from 7.4 to 4.0, to show pH-dependent property. Furthermore, NBD could not only selectively light up all four cancer cell lines, but also delineate xenograft tumor and orthotopic microtumor to guide surgical tumor resection, and track metastatic tissues. Particularly, after simple topical spray (three minutes later), NBD could rapidly and precisely distinguish the boundary ranges of three kinds of clinical cancer specimens including liver, colon, and lung cancers, with high tumor-to-normal tissue signal ratios (6.48~9.80). Conclusions: Therefore, the proposed fluorescent probe NBD may serve as a versatile NIR fluorogenic spray for the near-instant visualization of tumor margins and assisting surgeons in surgerical resection of clinical cancers.


Assuntos
Neoplasias do Colo , Neoplasias Pulmonares , Animais , Camundongos , Humanos , Corantes Fluorescentes , Camundongos Nus , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/cirurgia , Concentração de Íons de Hidrogênio
6.
Org Biomol Chem ; 21(24): 5046-5062, 2023 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-37266924

RESUMO

Campylobacter jejuni is a bacterial pathogen that causes hundreds of millions of cases of food-borne gastroenteritis worldwide annually. The infection caused by this bacterium is also associated with several forms of post-infectious autoimmune sequelae that can be very serious, including the life-threatening Guillain-Barré syndrome. The capsular polysaccharides (CPS) of C. jejuni HS:4 consist of a very unique repeating disaccharide unit that is characterized by a ß-1,4-linked 6-deoxy-ß-D-ido-heptopyranose and an N-acetyl-ß-D-glucosamine. Eliciting carbohydrate-specific antibodies against the CPS structures of C. jejuni HS:4 is an attractive strategy. The 6-deoxy-ido-configuration of the heptose combined with its ß-anomeric configuration makes the chemical synthesis of the disaccharide very challenging. Here, we report an efficient synthesis to obtain the key repeating disaccharide and its analog in reverse order plus a trisaccharide. Our synthesis features a highly efficient, one-step stereo- and regioselective conversion of ß-D-galacto-heptopyranosides to 6-deoxy-ß-D-ido-heptopyranosides via the intermediate 2,3-anhydro-ß-D-talo-heptopyranosides.


Assuntos
Campylobacter jejuni , Campylobacter jejuni/química , Polissacarídeos/química
7.
Biosens Bioelectron ; 234: 115343, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37167656

RESUMO

A fluorescent diagnostic probe for real-time intraoperative image-guided tumor resection can significantly improve the efficiency and quality of oncological therapy, but their development is challenging. Herein, a novel fluorescent diagnostic probe called HLTC based on ß-carboline was designed and synthesized. HLTC was found to show a ∼10-fold enhancement of fluorescence quantum field with pH from 7.4 to 4.0, indicating its imaging potential in acid environment which is a typical hallmark of the tumor microenvironment (TME). Following fluorescence microscopy imaging showed HLTC could emit specific signals in cancer cells and sections, by both one-photon excitation and two-photon excitation. Importantly, HLTC enabled the precise and rapid delineation of both transplanted tumor and clinical tumor tissues within several minutes of simple topical spray. The tumor-to-background ratio (TBR) was up to 10.2 ± 1.0 at clinical liver cancer tissues and 9.9 ± 0.3 at clinical colon cancer tissues, allowing precise tumor margin identification and the effective guidance of surgical tumor resection. Furthermore, CCK8 assay, pharmacokinetic evaluation, blood analysis and H&E staining were performed, which verified high biocompatibility and biosafety of HLTC at working concentration. These results reveal the exciting potential of this small-molecule fluorescent diagnostic probe for real-time fluorescence-based navigation during surgical tumor resection.


Assuntos
Técnicas Biossensoriais , Neoplasias Hepáticas , Humanos , Corantes Fluorescentes/química , Microambiente Tumoral
9.
Org Lett ; 24(47): 8667-8671, 2022 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-36383729

RESUMO

Pseudaminic acid and its biosynthetic altropyranoside precursors are bacterial components currently being investigated toward novel antibacterial strategies. One structural feature associated with these naturally occurring flagellar carbohydrates is the different N-acylation patterns on the two amido functionalities, posing a synthetic challenge. A new one-pot methodology is reported and a scope of diverse N2/N4-differentiated analogs are presented via a Staudinger reduction-mediated regiospecific O3 → N4 acyl migration, followed by an autonomous N2-acylation.


Assuntos
Acilação
10.
Nat Commun ; 13(1): 2445, 2022 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-35508608

RESUMO

Remyelination failure in multiple sclerosis (MS) contributes to progression of disability. The deficient repair results from neuroinflammation and deposition of inhibitors including chondroitin sulfate proteoglycans (CSPGs). Which CSPG member is repair-inhibitory or alters local inflammation to exacerbate injury is unknown. Here, we correlate high versican-V1 expression in MS lesions with deficient premyelinating oligodendrocytes, and highlight its selective upregulation amongst CSPG members in experimental autoimmune encephalomyelitis (EAE) lesions modeling MS. In culture, purified versican-V1 inhibits oligodendrocyte precursor cells (OPCs) and promotes T helper 17 (Th17) polarization. Versican-V1-exposed Th17 cells are particularly toxic to OPCs. In NG2CreER:MAPTmGFP mice illuminating newly formed GFP+ oligodendrocytes/myelin, difluorosamine (peracetylated,4,4-difluoro-N-acetylglucosamine) treatment from peak EAE reduces lesional versican-V1 and Th17 frequency, while enhancing GFP+ profiles. We suggest that lesion-elevated versican-V1 directly impedes OPCs while it indirectly inhibits remyelination through elevating local Th17 cytotoxic neuroinflammation. We propose CSPG-lowering drugs as potential dual pronged repair and immunomodulatory therapeutics for MS.


Assuntos
Encefalomielite Autoimune Experimental , Esclerose Múltipla , Células Precursoras de Oligodendrócitos , Remielinização , Animais , Diferenciação Celular , Encefalomielite Autoimune Experimental/patologia , Inflamação/patologia , Camundongos , Camundongos Endogâmicos C57BL , Esclerose Múltipla/patologia , Células Precursoras de Oligodendrócitos/metabolismo , Oligodendroglia/metabolismo , Remielinização/fisiologia , Versicanas/metabolismo
11.
Cells ; 11(3)2022 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-35159249

RESUMO

Iron deposition in the brain begins early in multiple sclerosis (MS) and continues unabated. Ferrous iron is toxic to neurons, yet the therapies used in MS do not counter iron neurotoxicity. Extracts of Hibiscus sabdariffa (HS) are used in many cultures for medicinal purposes. We collected a distinct HS extract and found that it abolished the killing of neurons by iron in culture; medications used in MS were ineffective when similarly tested. Neuroprotection by HS was not due to iron chelation or anthocyanin content. In free radical scavenging assays, HS was equipotent to alpha lipoic acid, an anti-oxidant being tested in MS. However, alpha lipoic acid was only modestly protective against iron-mediated killing. Moreover, a subfraction of HS without radical scavenging activity negated iron toxicity, whereas a commercial hibiscus preparation with anti-oxidant activity could not. The idea that HS might have altered properties within neurons to confer neuroprotection is supported by its amelioration of toxicity caused by other toxins: beta-amyloid, rotenone and staurosporine. Finally, in a mouse model of MS, HS reduced disability scores and ameliorated the loss of axons in the spinal cord. HS holds therapeutic potential to counter iron neurotoxicity, an unmet need that drives the progression of disability in MS.


Assuntos
Hibiscus , Esclerose Múltipla , Síndromes Neurotóxicas , Ácido Tióctico , Animais , Antioxidantes , Ferro , Camundongos , Esclerose Múltipla/tratamento farmacológico , Extratos Vegetais/farmacologia
12.
Cell Death Discov ; 7(1): 224, 2021 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-34455417

RESUMO

Hepatocellular carcinoma (HCC) is a heterogeneous tumor with an increased incidence worldwide accompanied by high mortality and dismal prognosis. Emerging evidence indicates that mesenchymal stem cells (MSCs)-derived exosomes possess protective effects against various human diseases by transporting microRNAs (miRNAs or miRs). We aimed to explore the role of exosomal miR-15a derived from MSCs and its related mechanisms in HCC. Exosomes were isolated from transduced MSCs and co-incubated with Hep3B and Huh7 cells. miR-15a expression was examined by RT-qPCR in HCC cells, MSCs, and secreted exosomes. CCK-8, transwell, and flow cytometry were used to detect the effects of miR-15a or spalt-like transcription factor 4 (SALL4) on cell proliferative, migrating, invasive, and apoptotic properties. A dual-luciferase reporter gene assay was performed to validate the predicted targeting relationship of miR-15a with SALL4. Finally, in vivo experiments in nude mice were implemented to assess the impact of exosome-delivered miR-15a on HCC. The exosomes from MSCs restrained HCC cell proliferative, migrating, and invasive potentials, and accelerated their apoptosis. miR-15a was expressed at low levels in HCC cells and could bind to SALL4, thus curtailing the proliferative, migrating, and invasive abilities of HCC cells. Exosomes successfully delivered miR-15a to HCC cells. Exosomal miR-15a depressed tumorigenicity and metastasis of HCC tumors in vivo. Overall, exosomal miR-15a from MSCs can downregulate SALL4 expression and thereby retard HCC development.

13.
Cell Death Dis ; 12(5): 489, 2021 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-33990548

RESUMO

Tumor recurrence is the major obstacle for pushing the envelope of liver transplantation for hepatocellular carcinoma (HCC) patients. The inflammatory cascades activated by acute liver graft injury promote tumor recurrence. We aimed to explore the role and mechanism of myeloid-derived suppressor cell (MDSC) mobilization induced by liver graft injury on tumor recurrence. By analyzing 331 HCC patients who received liver transplantation, the patients with graft weight ratio (GWR, the weight of liver graft divided by the estimated standard liver weight of recipient) <60% had higher tumor recurrence than GWR ≥60% ones. MDSCs and CXCL10/TLR4 levels were significantly increased in patients with GWR <60% or tumor recurrence. These findings were further validated in our rat orthotopic liver transplantation model. In CXCL10-/- and TLR4-/- mice of hepatic ischemia/reperfusion injury plus major hepatectomy (IRH) model, monocytic MDSCs, instead of granulocytic MDSCs, were significantly decreased. Importantly, CXCL10 deficiency reduced the accumulation of TLR4+ monocytic MDSCs, and CXCL10 increased MDSC mobilization in the presence of TLR4. Moreover, MMP14 was identified as the key molecule bridging CXCL10/TLR4 signaling and MDSC mobilization. Knockout or inhibition of CXCL10/TLR4 signaling significantly reduced the tumor growth with decreased monocytic MDSCs and MMP14 in the mouse tumor recurrent model. Our data indicated that monocytic MDSCs were mobilized and recruited to liver graft during acute phase injury, and to promote HCC recurrence after transplantation. Targeting MDSC mobilization via CXCL10/TLR4/MMP14 signaling may represent the therapeutic potential in decreasing post-transplant liver tumor recurrence.


Assuntos
Quimiocina CXCL10/metabolismo , Transplante de Fígado/métodos , Células Supressoras Mieloides/metabolismo , Animais , Humanos , Masculino , Camundongos , Ratos , Transdução de Sinais
14.
Nat Chem Biol ; 17(7): 806-816, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33958792

RESUMO

The central dogma of biology does not allow for the study of glycans using DNA sequencing. We report a liquid glycan array (LiGA) platform comprising a library of DNA 'barcoded' M13 virions that display 30-1,500 copies of glycans per phage. A LiGA is synthesized by acylation of the phage pVIII protein with a dibenzocyclooctyne, followed by ligation of azido-modified glycans. Pulldown of the LiGA with lectins followed by deep sequencing of the barcodes in the bound phage decodes the optimal structure and density of the recognized glycans. The LiGA is target agnostic and can measure the glycan-binding profile of lectins, such as CD22, on cells in vitro and immune cells in a live mouse. From a mixture of multivalent glycan probes, LiGAs identify the glycoconjugates with optimal avidity necessary for binding to lectins on living cells in vitro and in vivo.


Assuntos
Bacteriófago M13/química , Análise em Microsséries , Polissacarídeos/química , Animais , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Bacteriófago M13/genética , Bacteriófago M13/metabolismo , Camundongos , Polissacarídeos/genética , Polissacarídeos/metabolismo
15.
Mol Ther Oncolytics ; 20: 484-498, 2021 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-33718596

RESUMO

Previous evidence has highlighted M2 macrophage regulation of cancer cells via exosome shuttling of microRNAs (miRNAs or miRs). The current study set out to explore the possible role of M2 macrophage-derived exosomal miR-155-5p in regard to immune escape of colon cancer cells. Experimental data from quantitative reverse-transcriptase PCR (qRT-PCR) and western blot analysis revealed highly expressed miR-155-5p and interleukin (IL)-6 and poorly expressed ZC3H12B in M2 macrophage-derived exosomes. Additionally, miR-155-5p could be transferred by M2 macrophage-isolated exosomes to colon cancer cells, which targeted ZC3H12B by binding to the 3¢ UTR, as identified by dual luciferase reporter gene. Meanwhile, gain- and loss-of function experimentation on miR-155-5p and ZC3H12B in SW48 and HT29 cells cocultured with M2 macrophage-secreted exosomes demonstrated that miR-155-5p overexpression or ZC3H12B silencing promoted the proliferation and antiapoptosis ability of SW48 and HT29 cells, as well as augmenting the CD3+ T cell proliferation and the proportion of interferon (IFN)-γ+ T cells. Xenograft models confirmed that M2 macrophage-derived exosomal miR-155-5p reduced the ZC3H12B expression to upregulate IL-6, which consequently induced immune escape and tumor formation. Collectively, our findings indicated that M2 macrophage-derived exosomal miR-155-5p can potentially promote the immune escape of colon cancer by impairing ZC3H12B-mediated IL-6 stability reduction, thereby promoting the occurrence and development of colon cancer.

16.
J Cell Mol Med ; 25(8): 4040-4052, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33621431

RESUMO

Hepatocellular cancer (HCC) has been reported to belong to one of the highly vascularized solid tumours accompanied with angiogenesis of human umbilical vein endothelial cells (HUVECs). KDM5A, an attractive drug target, plays a critical role in diverse physiological processes. Thus, this study aims to investigate its role in angiogenesis and underlying mechanisms in HCC. ChIP-qPCR was utilized to validate enrichment of H3K4me3 and KDM5A on the promotor region of miR-433, while dual luciferase assay was carried out to confirm the targeting relationship between miR-433 and FXYD3. Scratch assay, transwell assay, Edu assay, pseudo-tube formation assay and mice with xenografted tumours were conducted to investigate the physiological function of KDM5A-miR-433-FXYD3-PI3K-AKT axis in the progression of HCC after loss- and gain-function assays. KDM5A p-p85 and p-AKT were highly expressed but miR-433 was down-regulated in HCC tissues and cell lines. Depletion of KDM5A led to reduced migrative, invasive and proliferative capacities in HCC cells, including growth and a lowered HUVEC angiogenic capacity in vitro. Furthermore, KDM5A suppressed the expression of miR-433 by demethylating H3K4me3 on its promoterregion. miR-433 negatively targeted FXYD3. Depleting miR-433 or re-expressing FXYD3 restores the reduced migrative, invasive and proliferative capacities, and lowers the HUVEC angiogenic capacity caused by silencing KDM5A. Therefore, KDM5A silencing significantly suppresses HCC tumorigenesis in vivo, accompanied with down-regulated miR-433 and up-regulated FXYD3-PI3K-AKT axis in tumour tissues. Lastly, KDM5A activates the FXYD3-PI3K-AKT axis to enhance angiogenesis in HCC by suppressing miR-433.


Assuntos
Carcinoma Hepatocelular/patologia , Proteínas de Membrana/antagonistas & inibidores , MicroRNAs/genética , Proteínas de Neoplasias/antagonistas & inibidores , Neovascularização Patológica/prevenção & controle , Fosfatidilinositol 3-Quinases/química , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteína 2 de Ligação ao Retinoblastoma/antagonistas & inibidores , Idoso , Apoptose , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Movimento Celular , Proliferação de Células , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Neovascularização Patológica/genética , Neovascularização Patológica/metabolismo , Neovascularização Patológica/patologia , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Prognóstico , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteína 2 de Ligação ao Retinoblastoma/genética , Proteína 2 de Ligação ao Retinoblastoma/metabolismo , Taxa de Sobrevida , Células Tumorais Cultivadas
17.
RSC Adv ; 11(19): 11583-11594, 2021 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-35423663

RESUMO

Bacterial nonulosonic acids such as pseudaminic acids and others constitute a family of 9-carbon monosaccharides that contain a common 3-deoxy-2-ketoacid fragment but differ in their stereochemistries at 5 stereogenic centers between C-4 to C-8. Their unique structures make them attractive targets for use as antigens in vaccinations to combat drug-resistant bacterial infections and their challenging stereochemistries have attracted considerable attention from chemists. In this work we report the development of an improved synthesis for 2,4-di-N-acetyl-l-altrose (l-2,4-Alt-diNAc), which is a key hexose required for the chemical and chemoenzymatic synthesis of pseudaminic acids. Using l-fucose as a starting material, our synthesis overcomes several pitfalls in previously reported syntheses.

18.
Bioorg Chem ; 105: 104360, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33074118

RESUMO

A series of mono- and di-methylenecyclohexenone derivatives, 3a-f and 4a-f, respectively, were designed and synthesized from piperlongumine (PL) and their in vitro and in vivo pharmacological properties were evaluated. A majority of the compounds exhibited a potent antiproliferative effect on five human cancer cell lines, especially those causing breast cancer. Compound 4f showed the highest antiproliferative potency among all of the compounds, almost a 10-fold higher inhibitory potency against thioredoxin reductase (TrxR) compared with PL in cells causing breast cancer. In addition, 4f was found to increase the levels of reactive oxygen species (ROS), thus leading to more potent antiproliferative effects. More importantly, the suppression assays of migration and invasion revealed that compound 4f could reverse the epithelial-mesenchymal transition induced by the transforming growth factor ß1, and exhibit prominent anti-metastasis effects. Compound 4f also showed strong inhibition potency toward solid tumors of breast cancer in vivo. Our findings show that compound 4f is a promising therapeutic candidate in the treatment of breast cancer, which, however, needs further research to be proved.


Assuntos
Antineoplásicos/farmacologia , Cicloexenos/farmacologia , Inibidores Enzimáticos/farmacologia , Tiorredoxina Dissulfeto Redutase/antagonistas & inibidores , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cicloexenos/síntese química , Cicloexenos/química , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Humanos , Masculino , Neoplasias Mamárias Experimentais/tratamento farmacológico , Neoplasias Mamárias Experimentais/metabolismo , Neoplasias Mamárias Experimentais/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Estrutura Molecular , Espécies Reativas de Oxigênio/análise , Espécies Reativas de Oxigênio/metabolismo , Relação Estrutura-Atividade , Tiorredoxina Dissulfeto Redutase/metabolismo , Células Tumorais Cultivadas
19.
Curr Probl Cancer ; 44(6): 100612, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32517878

RESUMO

OBJECTIVE: We used meta-analysis to evaluate the efficacy of transcatheter hepatic arterial chemoembolization (TACE) for the treatment of intrahepatic cholangiocarcinoma (ICC). METHODS: We performed the meta-analysis using the R 3.12 software and the quality evaluation of data using the Newcastle-Ottawa Scale. The main outcomes were recorded as 1-year overall survival (OS), 3-year OS, 5-year OS, and hazard ratio (HR) of TACE treatment or non-TACE treatment. The heterogeneity test was performed using the Q-test based on chi-square and I2 statistics. Egger's test was used to test the publication bias. The odds ratio or HR and 95% confidence interval (CI) were used to represent the effect index. RESULTS: Nine controlled clinical trials involving 1724 participants were included in this study; patients came mainly from China, Italy, South Korea, and Germany. In the OS meta-analysis, the 1-year and 3-year OS showed significant heterogeneity, but not the 5-year OS. TACE increased the 1-year OS (odds ratio = 2.66, 95% CI: 1.10-6.46) of the patients with ICC, but the 3- and 5-year OS rates were not significantly increased. The results had no publication bias, but the stability was weak. The HR had significant heterogeneity (I2 = 0%, P= 0.54). TACE significantly decreased the HR of ICC patients (HR = 0.59, 95% CI: 0.48-0.73). The results had no publication bias, and the stability was good. CONCLUSIONS: Treatment with TACE is effective for patients with ICC. Regular updating and further research and analysis still need to be carried out.


Assuntos
Neoplasias dos Ductos Biliares/terapia , Quimioembolização Terapêutica/métodos , Quimioterapia Adjuvante/métodos , Colangiocarcinoma/terapia , Artéria Hepática , Infusões Intra-Arteriais/métodos , Neoplasias dos Ductos Biliares/patologia , Colangiocarcinoma/patologia , Humanos , Prognóstico
20.
Mol Ther Nucleic Acids ; 21: 229-241, 2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32585630

RESUMO

Numerous studies have suggested that dysregulated long noncoding RNAs (lncRNAs) contributed to the development and progression of many cancers. lncRNA OIP5 antisense RNA 1 (OIP5-AS1) has been reported to be increased in several cancers. However, the roles of OIP5-AS1 in liver hepatocellular carcinoma (LIHC) remain to be investigated. In this study, we demonstrated that OIP5-AS1 was upregulated in LIHC tissue specimens and its overexpression was associated with the poor survival of patients with LIHC. Furthermore, loss-of function experiments indicated that OIP5-AS1 promoted cell proliferation and inhibited cell apoptosis both in vitro and in vivo. Moreover, binding sites between OIP5-AS1 and hsa-miR-26a-3p as well as between hsa-miR-26a-3p and EPHA2 were confirmed by luciferase assays. Finally, a rescue assay was performed to prove the effect of the OIP5-AS1/hsa-miR-26a-3p/EPHA2 axis on LIHC cell biological behaviors. Based on all of the above findings, our results suggested that OIP5-AS1 promoted LIHC cell proliferation and invasion via regulating the hsa-miR-26a-3p/EPHA2 axis.

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