RESUMO
BACKGROUND: The Indian Armed Forces are fighting the battle at extreme High Altitude, the most inhospitable terrain in the world, for the last thirty five years. The stress of being isolated under harsh environmental conditions on a daily basis can have an adverse effect on their mind. However, so far, no study has been undertaken to assess the psychological effects of deployment at extreme High Altitude. METHODS: Three hundred thirty-four troops selected for deployment were initially evaluated using the General Health Questionnaire-12 (GHQ-12) and Armed Forces Medical College Life Events Scale (AFMC LES) as screening tools to assess mental health status after obtaining ethical clearance and informed consent. On deinduction after a deployment for more than three months, they were reassessed. The data collected were statistically analysed. RESULTS: As per GHQ-12 evaluation, after the deployment score increased from 0.2574 to 0.9162, but remained lower than the 'caseness' level of 2. Among the 79 troops with a score of 2 and more, the majority were married and had past history of tenures at high-altitude areas. There was statistically significant increase in the AFMC LES scores also on deployment. CONCLUSION: Deployment at extremely high-altitude areas for even three months produces significant psychological morbidity among troops.
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Glial tumor is one of the intrinsic brain tumors with high migratory and infiltrative potential. This essentially contributes to the overall poor prognosis by circumvention of conventional treatment regimen in glioma. The underlying mechanism in gliomagenesis is bestowed by two processes- Extracellular matrix (ECM) Remodeling and Epithelial to mesenchymal transition (EMT). Heat Shock Family of proteins (HSPs), commonly known as "molecular chaperons" are documented to be upregulated in glioma. A positive correlation also exists between elevated expression of HSPs and invasive capacity of glial tumor. HSPs overexpression leads to mutational changes in glioma, which ultimately drive cells towards EMT, ECM modification, malignancy and invasion. Differential expression of HSPs - a factor providing cytoprotection to glioma cells, also contributes towards its radioresistance /chemoresistance. Various evidences also display upregulation of EMT and ECM markers by various heat shock inducing proteins e.g. HSF-1. The aim of this review is to study in detail the role of HSPs in EMT and ECM leading to radioresistance/chemoresistance of glioma cells. The existing treatment regimen for glioma could be enhanced by targeting HSPs through immunotherapy, miRNA and exosome mediated strategies. This could be envisaged by better understanding of molecular mechanisms underlying glial tumorigenesis in relation to EMT and ECM remodeling under HSPs influence. Our review might showcase fresh potential for the development of next generation therapeutics for effective glioma management.
Assuntos
Neoplasias Encefálicas/genética , Proteínas de Ligação a DNA/genética , Regulação Neoplásica da Expressão Gênica , Glioma/genética , Proteínas de Choque Térmico/genética , MicroRNAs/genética , Fatores de Transcrição/genética , Antineoplásicos/uso terapêutico , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/cirurgia , Neoplasias Encefálicas/terapia , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/metabolismo , Progressão da Doença , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Transição Epitelial-Mesenquimal/efeitos da radiação , Matriz Extracelular/efeitos dos fármacos , Matriz Extracelular/metabolismo , Matriz Extracelular/patologia , Matriz Extracelular/efeitos da radiação , Raios gama/uso terapêutico , Glioma/patologia , Glioma/cirurgia , Glioma/terapia , Fatores de Transcrição de Choque Térmico , Proteínas de Choque Térmico/antagonistas & inibidores , Proteínas de Choque Térmico/metabolismo , Humanos , Lactamas Macrocíclicas/uso terapêutico , MicroRNAs/antagonistas & inibidores , MicroRNAs/metabolismo , Invasividade Neoplásica , Transdução de Sinais , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/metabolismoRESUMO
BACKGROUND: Gold nanorods, by virtue of surface plasmon resonance, convert incident light energy (NIR) into heat energy which induces hyperthermia. We designed unique, multifunctional, gold nanorod embedded block copolymer micelle loaded with GW627368X for targeted drug delivery and photothermal therapy. METHODS: Glutathione responsive diblock co-polymer was synthesized by RAFT process forming self-assembled micelle on gold nanorods prepared by seed mediated method and GW627368X was loaded on to the reduction responsive gold nanorod embedded micelle. Photothermal therapy was administered using cwNIR laser (808nm; 4W/cm2). Efficacy of nanoformulated GW627368X, photothermal therapy and combination of both were evaluated in vitro and in vivo. RESULTS: In response to photothermal treatment, cells undergo regulated, patterned cell death by necroptosis. Combining GW627368X with photothermal treatment using single nanoparticle enhanced therapeutic outcome. In addition, these nanoparticles are effective X-ray CT contrast agents, thus, can help in monitoring treatment. CONCLUSION: Reduction responsive nanorod embedded micelle containing folic acid and lipoic acid when treated on cervical cancer cells or tumour bearing mice, aggregate in and around cancer cells. Due to high glutathione concentration, micelles degrade releasing drug which binds surface receptors inducing apoptosis. When incident with 808nm cwNIR lasers, gold nanorods bring about photothermal effect leading to hyperthermic cell death by necroptosis. Combination of the two modalities enhances therapeutic efficacy by inducing both forms of cell death. GENERAL SIGNIFICANCE: Our proposed treatment strategy achieves photothermal therapy and targeted drug delivery simultaneously. It can prove useful in overcoming general toxicities associated with chemotherapeutics and intrinsic/acquired resistance to chemo and radiotherapy.
Assuntos
Sistemas de Liberação de Medicamentos/métodos , Ouro/química , Hipertermia Induzida , Micelas , Nanotubos/química , Neoplasias/terapia , Fototerapia , Polímeros/química , Animais , Materiais Biocompatíveis/farmacologia , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Meios de Contraste/química , Liberação Controlada de Fármacos , Endocitose/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , Isoindóis/farmacologia , Camundongos , Nanotubos/ultraestrutura , Polímeros/síntese química , Espectrofotometria Ultravioleta , Espectroscopia de Luz Próxima ao Infravermelho , Sulfonamidas/farmacologia , Raios XRESUMO
Glioma accounts for the majority of human brain tumors. With prevailing treatment regimens, the patients have poor survival rates. In spite of current development in mainstream glioma therapy, a cure for glioma appears to be out of reach. The infiltrative nature of glioma and acquired resistance substancially restrict the therapeutic options. Better elucidation of the complicated pathobiology of glioma and proteogenomic characterization might eventually open novel avenues for the design of more sophisticated and effective combination regimens. This could be accomplished by individually tailoring progressive neuroimaging techniques, terminating DNA synthesis with prodrug-activating genes, silencing gliomagenesis genes (gene therapy), targeting miRNA oncogenic activity (miRNA-mRNA interaction), combining Hedgehog-Gli/Akt inhibitors with stem cell therapy, employing tumor lysates as antigen sources for efficient depletion of tumor-specific cancer stem cells by cytotoxic T lymphocytes (dendritic cell vaccination), adoptive transfer of chimeric antigen receptor-modified T cells, and combining immune checkpoint inhibitors with conventional therapeutic modalities. Thus, the present review captures the latest trends associated with the molecular mechanisms involved in glial tumorigenesis as well as the limitations of surgery, radiation and chemotherapy. In this article we also critically discuss the next generation molecular therapeutic strategies and their mechanisms for the successful treatment of glioma.
Assuntos
Neoplasias Encefálicas/terapia , Encéfalo/patologia , Glioma/terapia , Terapia de Alvo Molecular/tendências , Antineoplásicos/uso terapêutico , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Carcinogênese/genética , Carcinogênese/patologia , Glioma/genética , Glioma/patologia , Humanos , Terapia de Alvo Molecular/métodosRESUMO
Amplification of PI3K-Akt pathway promotes radioresistance in various cancers including colorectal carcinoma. Local recurrence in colon cancer causes poor prognosis affecting overall survival of cancer-affected patient population. To avoid local recurrence, pre-operative or post-operative additional radiotherapy is given. However, main concern regarding radiotherapy is to increase the radiosensitivity of malignant cell without hampering the activities of normal cells. In this context, addition of two or more than two chemotherapeutic drugs as a radiosensitizer is a common practice in radiation biology. BI-69A11 earlier showed potential apoptosis-inducing effect in melanoma and colon carcinoma. Celecoxib showed anti-cancer effects in both COX-2 dependent and independent pathways and used to act as a radiosensitizing enhancer. Here, we suggest that the combination of BI-69A11 and celecoxib inhibits the phosphorylation of ataxia telangiectasia mutated (ATM) kinase and DNA-PK responsible for ionizing radiation (IR)-induced double-strand break (DSB) repair. Moreover, the combinatorial effect of BI-69A11 and celecoxib attenuates the IR-induced G2/M cell cycle arrest. Furthermore, this combination also impairs IR-induced activation of Akt and downstream targets of ATM. This might lead to induced activation of apoptotic pathway after triple therapy treatment modulating pro-apoptotic and anti-apoptotic proteins. This activation of apoptotic pathway also showed the interdependence of PUMA and BAD in triple combination-treated colon cancer cells in a p53 independent manner. This study reveals the therapeutic potential of the triple combination therapy in prevention of radioresistance. Besides, it also demonstrates the cytotoxic effects of triple combination therapy in colon cancer. This study shows utility and potential implication on safety of the patients undergoing radiation therapy.
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Carcinoma/tratamento farmacológico , Carcinoma/radioterapia , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/radioterapia , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Benzimidazóis/administração & dosagem , Carcinoma/patologia , Celecoxib/administração & dosagem , Neoplasias do Colo/patologia , Terapia Combinada , Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Reparo do DNA/efeitos da radiação , Células HCT116 , Humanos , Quinolonas/administração & dosagem , Tolerância a Radiação/efeitos dos fármacos , Tolerância a Radiação/efeitos da radiação , Radiação Ionizante , Radiossensibilizantes/administração & dosagem , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/efeitos da radiaçãoRESUMO
A new fluorescent photoremovable protecting group (FPRPG) based on acetylcarbazole framework has been explored for the first time release of single and dual (similar or different) substrates from single chromophore. Mechanistic studies of the photorelease process revealed that photorelease of two (similar or different) substrates from acetyl carbazole proceeds via a stepwise pathway. Further, we constructed photoresponsive dual drug delivery system (DDS) to release two different anticancer drugs (caffeic acid and chlorambucil, 1 equiv each). In vitro study reveals that our DDS exhibit excellent properties like biocompatibility, cellular uptake, and photoregulated dual drug release.
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Aminoácidos/química , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Carbazóis/química , Ácidos Carboxílicos/química , Sistemas de Liberação de Medicamentos , Neoplasias/tratamento farmacológico , Linhagem Celular Tumoral , Humanos , Espectroscopia de Ressonância Magnética/métodos , Fotoquímica , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Espectrofotometria UltravioletaRESUMO
Probiotics offer a promising prophylactic approach against various pathogens and represent an alternative strategy to combat biofilm-related infections. In this study, we isolated vaginal commensal microbiota from 54 healthy Indian women to investigate their probiotic traits. We primarily explored the ability of cell-free supernatant (CFS) from Lactobacilli to prevent Uropathogenic Escherichia coli (UPEC) colonization and biofilm formation. Our findings revealed that CFS effectively reduced UPEC's swimming and swarming motility, decreased cell surface hydrophobicity, and hindered matrix production by downregulating specific genes (fimA, fimH, papG, and csgA). Subsequent GC-MS analysis identified Tryptamine, a monoamine compound, as the potent bioactive substance from Lactobacilli CFS, inhibiting UPEC biofilms with an MBIC of 4 µg/ml and an MBEC of 8 µg/ml. Tryptamine induced significant changes in E. coli colony biofilm morphology, transitioning from the Red, Dry, and Rough (RDAR) to the Smooth and White phenotype, indicating reduced extracellular matrix production. Biofilm time-kill assays demonstrated a four-log reduction in UPEC viability when treated with Tryptamine, highlighting its potent antibacterial properties, comparable to CFS treatment. Biofilm ROS assays indicated a significant elevation in ROS generation within UPEC biofilms, suggesting a potential antibacterial mechanism. Gene expression studies with Tryptamine-treated samples showed a reduction in expression of curli gene (csgA), consistent with CFS treatment. This study underscores the potential of Tryptamine from probiotic Lactobacilli CFS as a promising antibiofilm agent against UPEC biofilms.
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Biofilmes , Lactobacillus , Probióticos , Triptaminas , Escherichia coli Uropatogênica , Vagina , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Humanos , Triptaminas/farmacologia , Feminino , Escherichia coli Uropatogênica/efeitos dos fármacos , Escherichia coli Uropatogênica/fisiologia , Probióticos/farmacologia , Vagina/microbiologia , Lactobacillus/efeitos dos fármacos , Lactobacillus/metabolismo , Lactobacillus/fisiologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/prevenção & controle , Adulto , Antibacterianos/farmacologiaRESUMO
Dendrimers as vectors for gene delivery were established, primarily by utilizing few prominent dendrimer types so far. We report herein studies of DNA complexation efficacies and gene delivery vector properties of a nitrogen-core poly(propyl ether imine) (PETIM) dendrimer, constituted with 22 tertiary amine internal branches and 24 primary amines at the periphery. The interaction of the dendrimer with pEGFPDNA was evaluated through UV-vis, circular dichroism (CD) spectral studies, ethidium bromide fluorescence emission quenching, thermal melting, and gel retardation assays, from which most changes to DNA structure during complexation was found to occur at a weight ratio of dendrimer:DNA â¼ 2:1. The zeta potential measurements further confirmed this stoichiometry at electroneutrality. The structure of a DNA oligomer upon dendrimer complexation was simulated through molecular modeling and the simulation showed that the dendrimer enfolded DNA oligomer along both major and minor grooves, without causing DNA deformation, in 1:1 and 2:1 dendrimer-to-DNA complexes. Atomic force microscopy (AFM) studies on dendrimer-pEGFP DNA complex showed an increase in the average z-height as a result of dendrimers decorating the DNA, without causing a distortion of the DNA structure. Cytotoxicity studies involving five different mammalian cell lines, using [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide] (MTT) assay, reveal the dendrimer toxicity profile (IC50) values of â¼400-1000 µg mL(-1), depending on the cell line tested. Quantitative estimation, using luciferase assay, showed that the gene transfection was at least 100 times higher when compared to poly(ethylene imine) branched polymer, having similar number of cationic sites as the dendrimer. The present study establishes the physicochemical behavior of new nitrogen-core PETIM dendrimer-DNA complexes, their lower toxicities, and efficient gene delivery vector properties.
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DNA/administração & dosagem , Dendrímeros/química , Éteres/química , Iminas/química , Transfecção , Animais , Linhagem Celular , DNA/química , DNA/genética , Dendrímeros/toxicidade , Éteres/toxicidade , Humanos , Iminas/toxicidade , Simulação de Dinâmica MolecularRESUMO
INTRODUCTION: Facial contour deformities presents with varied aetiology and degrees severity. Accurate assessment, selecting a suitable tissue and sculpturing it to fill the defect is challenging and largely subjective. Objective assessment with imaging and software is not always feasible and preparing a template is complicated. A three-dimensional (3D) wax template pre-fabricated over the facial moulage aids surgeons to fulfil these tasks. Severe deformities demand a stable vascular tissue for an acceptable outcome. MATERIALS AND METHODS: We present review of eight consecutive patients who underwent augmentation of facial contour defects with free flaps between June 2005 and January 2011. De-epithelialised free anterolateral thigh (ALT) flap in three, radial artery forearm flap and fibula osteocutaneous flap in two each and groin flap was used in one patient. A 3D wax template was fabricated by augmenting the deformity on facial moulage. It was utilised to select the flap, to determine the exact dimensions and to sculpture intraoperatively. Ancillary procedures such as genioplasty, rhinoplasty and coloboma correction were performed. RESULTS: The average age at the presentation was 25 years and average disease free interval was 5.5 years and all flaps survived. Mean follow-up period was 21.75 months. The correction was aesthetically acceptable and was maintained without any recurrence or atrophy. CONCLUSION: The 3D wax template on facial moulage is simple, inexpensive and precise objective tool. It provides accurate guide for the planning and execution of the flap reconstruction. The selection of the flap is based on the type and extent of the defect. Superiority of vascularised free tissue is well-known and the ALT flap offers a versatile option for correcting varying degrees of the deformities. Ancillary procedures improve the overall aesthetic outcomes and minor flap touch-up procedures are generally required.
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We study the complexation of nontoxic, native poly(propyl ether imine) dendrimers with single-walled carbon nanotubes (SWNTs). The interaction was monitored by measuring the quenching of inherent fluorescence of the dendrimer. The dendrimer-nanotube binding also resulted in the increased electrical resistance of the hole doped SWNT, due to charge-transfer interaction between dendrimer and nanotube. This charge-transfer interaction was further corroborated by observing a shift in frequency of the tangential Raman modes of SWNT. We also report the effect of acidic and neutral pH conditions on the binding affinities. Experimental studies were supplemented by all atom molecular dynamics simulations to provide a microscopic picture of the dendrimer-nanotube complex. The complexation was achieved through charge transfer and hydrophobic interactions, aided by multitude of oxygen, nitrogen, and n-propyl moieties of the dendrimer.
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Dendrímeros/química , Éteres/química , Iminas/química , Nanotubos de Carbono/química , Simulação de Dinâmica Molecular , Estrutura Molecular , Água/químicaRESUMO
Non-coding RNAs are known to participate in cancer initiation, progression, and metastasis by regulating the status of chromatin epigenetics and gene expression. Although these non-coding RNAs do not possess defined protein-coding potential, they are involved in the expression and stability of messenger RNA (mRNA). The length of microRNAs (miRs) ranges between 20 and 22 nt, whereas, long non-coding RNAs (lncRNAs) length ranges between 200 nt to 1â¯Kb. In the case of circular RNAs (circRNAs), the size varies depending upon the length of the exon from where they were derived. Epigenetic regulations of miR and lncRNA genes will influence the gene expression by modulating histone acetylation and methylation patterns. Especially, lncRNAs will act as a scaffold for various epigenetic proteins, such as EZH2 and LSD1, and influence the chromatin epigenetic state at various genomic loci involved at silencing. Thus investigations on the expression of lncRNAs and designing drugs to modulate the expression of these genes will have a profound impact on future therapeutics against cancers such as Glioblastoma Multiforme (GBM) and also against various other diseases. With the recent advancements in genome-wide transcriptomic studies, scientists are focused on the non-coding RNAs and their regulations on various cellular processes involved in GBM and on other types of cancer as well as trying to understand possible epigenetic modulations that help in generating promising therapeutics for the future generations. In this review, the involvement of epigenetic proteins, enzymes that change chromatin architecture and epigenetic landscape and new roles of lncRNAs that are involved in GBM progression are elaborately discussed.
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Neoplasias Encefálicas/tratamento farmacológico , Glioblastoma/tratamento farmacológico , MicroRNAs/genética , RNA Longo não Codificante/genética , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Neoplasias Encefálicas/genética , Ensaios Clínicos como Assunto , Epigênese Genética/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Redes Reguladoras de Genes/efeitos dos fármacos , Glioblastoma/genética , HumanosRESUMO
Glioblastoma (GBM) is the most malignant form of brain tumor posing a major threat to cancer amelioration. Temozolomide (TMZ) resistance is one of the major hurdles towards GBM prognosis. Oxidative stress and ECM remodeling are the two important processes involved in gaining chemo-resistance. Here, we established NFE2L2, an important member of oxidative stress regulation elevated in resistant cells, to be playing a transcriptional regulatory role on MMP-2, an ECM remodeling marker. This link led us to further explore targeted molecules to inhibit NFE2L2, thus affecting MMP-2, an important member promoting chemo-resistance. Thus, diosgenin was proposed as a novel NFE2L2 inhibitor acting as an alternative strategy to prevent the high dose administration of TMZ. Combinatorial therapy of diosgenin and TMZ significantly reduced the dosage regimen of TMZ and also showed affectivity in hitherto TMZ resistant GBM cells. GBM cells underwent apoptosis and early cell cycle arrest with significant reduction in MMP-2 levels. Thus preclinical validation of molecular interaction between diosgenin and NFE2L2 down-regulating MMP-2, EMT markers and promoting apoptosis, offers rationale for new therapeutic horizons in the field of glioblastoma management.
Assuntos
Antineoplásicos Alquilantes/administração & dosagem , Neoplasias Encefálicas/metabolismo , Glioblastoma/metabolismo , Metaloproteinase 2 da Matriz/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Temozolomida/administração & dosagem , Animais , Sequência de Bases , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/genética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/fisiologia , Relação Dose-Resposta a Droga , Sistemas de Liberação de Medicamentos/métodos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/fisiologia , Glioblastoma/tratamento farmacológico , Glioblastoma/genética , Humanos , Metaloproteinase 2 da Matriz/genética , Camundongos Nus , Fator 2 Relacionado a NF-E2/antagonistas & inibidores , Fator 2 Relacionado a NF-E2/genética , Estrutura Terciária de Proteína , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
BACKGROUND: Epithelial to mesenchymal transition (EMT) and extracellular matrix (ECM) remodeling, are the two elemental processes promoting glioblastoma (GBM). In the present work we propose a mechanistic modelling of GBM and in process establish a hypothesis elucidating critical crosstalk between heat shock proteins (HSPs) and matrix metalloproteinases (MMPs) with synergistic upregulation of EMT-like process and ECM remodeling. METHODS: The interaction and the precise binding site between the HSP and MMP proteins was assayed computationally, in-vitro and in GBM clinical samples. RESULTS: A positive crosstalk of HSP27 with MMP-2 and MMP-9 was established in both GBM patient tissues and cell-lines. This association was found to be of prime significance for ECM remodeling and promotion of EMT-like characteristics. In-silico predictions revealed 3 plausible interaction sites of HSP27 interacting with MMP-2 and MMP-9. Site-directed mutagenesis followed by in-vitro immunoprecipitation assay (IP) with 3 mutated recombinant HSP27, confirmed an interface stretch containing residues 29-40 of HSP27 to be a common interaction site for both MMP-2 and MMP-9. This was further validated with in-vitro IP of truncated (sans AA 29-40) recombinant HSP27 with MMP-2 and MMP-9. CONCLUSION: The association of HSP27 with MMP-2 and MMP-9 proteins along with the identified interacting stretch has the potential to contribute towards drug development to inhibit GBM infiltration and migration. GENERAL SIGNIFICANCE: Current findings provide a novel therapeutic target for GBM opening a new horizon in the field of GBM management.
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Neoplasias Encefálicas/terapia , Glioblastoma/terapia , Proteínas de Choque Térmico HSP27/metabolismo , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 8 da Matriz/metabolismo , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Progressão da Doença , Glioblastoma/metabolismo , Glioblastoma/patologia , HumanosRESUMO
Epithelial to mesenchymal transition (EMT) is compulsory for metastatic dissemination and is stimulated by TGF-ß. Although targeting EMT has significant therapeutic potential, very few pharmacological agents have been shown to exert anti-metastatic effects. BI-69A11, a competitive Akt inhibitor, displays anti-tumor activity toward melanoma and colon carcinoma. This study provides molecular and biochemical insights into the effects of BI-69A11 on EMT in colon carcinoma cells in vitro and in vivo. BI-69A11 inhibited metastasis-associated cellular migration, invasion and adhesion by inhibiting the Akt-ß-catenin pathway. The underlying mechanism of BI-69A11-mediated inhibition of EMT included suppression of nuclear transport of ß-catenin and diminished phosphorylation of ß-catenin, which was accompanied by enhanced E-cadherin-ß-catenin complex formation at the plasma membrane. Additionally, BI-69A11 caused increased accumulation of vinculin in the plasma membrane, which fortified focal adhesion junctions leading to inhibition of metastasis. BI-69A11 downregulated activation of the TGF-ß-induced non-canonical Akt/NF-κB pathway and blocked TGF-ß-induced enhanced expression of Snail causing restoration of E-cadherin. Overall, this study enhances our understanding of the molecular mechanism of BI-69A11-induced reversal of EMT in colorectal carcinoma cells in vitro, in vivo and in TGF-ß-induced model systems.
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Antígenos CD/metabolismo , Antineoplásicos/farmacologia , Benzimidazóis/farmacologia , Caderinas/metabolismo , Neoplasias Colorretais/patologia , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Quinolonas/farmacologia , beta Catenina/metabolismo , Adesão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Neoplasias Colorretais/tratamento farmacológico , Humanos , Invasividade Neoplásica/patologia , Metástase Neoplásica/patologia , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Fator de Crescimento Transformador beta/metabolismo , Vinculina/metabolismoRESUMO
A new strategy for the detection of hypoxia and NO succeeded by photocontrolled delivery of an anticancer agent has been demonstrated. The developed system is able to produce distinct responses (dual channel) upon interaction with hypoxia and NO. This probe can also release anticancer drugs upon photoirradiation acting potentially as both a dual-analyte imaging agent and a prodrug.
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Nitric oxide photodonor (NOD) conjugated perylene tetracarboxylate ester (TPT) based fluorescent organic TPT(NOD)4 nanoparticles (NPs) with aggregation induced NIR emission have shown photoinduced nitric oxide delivery along with a red to green emission transition. Time dependent imaging and dose dependent cytotoxicity studies of these NPs using U87MG cells demonstrate the self monitoring and real time reporting abilities and potential anticancer activity of the system, respectively.
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Cholesterol (Chol) is a ubiquitous steroidal component of cell membrane and is known to modulate the packing of phospholipids within the bilayer. Thus, Chol has been frequently used in the formulation and study of artificial "model membranes" like vesicles and liposomes. In this work, we have developed a novel anionic surfactant by conjugating two biomolecules, cholesterol and γ-aminobutyric acid via a urethane linkage. We have studied its physicochemical behavior in aqueous buffer. The surfactant has been shown to spontaneously form small unilamellar vesicles above a very low critical concentration in aqueous neutral buffer at room temperature. The vesicle phase was characterized by use of fluorescence probe, transmission electron microscopy and dynamic light scattering (DLS) techniques. The vesicle bilayer was found to be much less polar as well as more viscous compared to the bulk water. The vesicle stability with respect to change of temperature, pH, and ageing time was investigated by fluorescence probe and DLS techniques. The loading efficiency of the vesicles for the hydrophobic drug, curcumin, was determined and its release under physiological condition was studied. The in vitro cellular uptake of curcumin-loaded vesicles to human breast cancer cell line (MDA-MB-231) also was investigated. The MTT assay showed that the surfactant was non-cytotoxic up to a relatively high concentration.
Assuntos
Antineoplásicos Fitogênicos/química , Colesterol/química , Curcumina/química , Tensoativos/química , Ácido gama-Aminobutírico/química , Animais , Antineoplásicos Fitogênicos/administração & dosagem , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Curcumina/administração & dosagem , Portadores de Fármacos , Liberação Controlada de Fármacos , Difusão Dinâmica da Luz/métodos , Fluorescência , Humanos , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Lipossomos , Camundongos , Micelas , Células NIH 3T3 , Tamanho da Partícula , Propriedades de Superfície , ViscosidadeRESUMO
We report a new strategy, viz. cascade photocaging, for protecting diethylamine diazeniumdiolate (O2-position), a light sensitive molecule. Upon photolysis, the cascade photocage at first releases the light activatable linker (latent fluorophore) O2-caged diazeniumdiolate, which undergoes spontaneous 1,8-elimination, triggering the release of the diazeniumdiolate anion and the fluorophore.
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Tumor angiogenesis and invasion are deregulated biological processes that drive multistage transformation of tumors from a benign to a life-threatening malignant state activating multiple signaling pathways including MD-2/TLR4/NF-κB. Development of potential inhibitors of this signaling is emerging area for discovery of novel cancer therapeutics. In the current investigation, we identified Iturin A (A lipopeptide molecule from Bacillus megaterium) as a potent inhibitor of angiogenesis and cancer invasion by various in vitro and in vivo methods. Iturin A was found to suppress VEGF, a powerful inducer of angiogenesis and key player in tumor invasion, as confirmed by ELISA, western blot and real time PCR. Iturin A inhibited endothelial tube arrangement, blood capillary formation, endothelial sprouting and vascular growth inside the matrigel. In addition, Iturin A inhibited MMP-2/9 expression in MDA-MB-231 and HUVEC cells. Cancer invasion, migration and colony forming ability were significantly hampered by Iturin A. Expressions of MD-2/TLR4 and its downstream MyD88, IKK-α and NF-κB were also reduced in treated MDA-MB-231 and HUVEC cells. Western blot and immunofluorescence study showed that nuclear accumulation of NF-κB was hampered by Iturin A. MD-2 siRNA or plasmid further confirmed the efficacy of Iturin A by suppressing MD-2/TLR4 signaling pathway. The in silico docking study showed that the Iturin A interacted well with the MD-2 in MD-2/TLR4 receptor complex. Conclusively, inhibition of MD-2/TLR4 complex with Iturin A offered strategic advancement in cancer therapy.