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1.
Adv Mater ; 36(9): e2309212, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38041711

RESUMO

The essential virtues of aqueous zinc battery chemistry stem from the energy-dense zinc metal anode and mild aqueous electrolytes. Yet, their incompatibility - as exposed by zinc's corrosion and associated dendrite problem - poses a challenge to achieving improved cycle life under practically relevant parameters. While electrolyte additives are a scalable strategy, additives that can function at low volume concentrations remain elusive. Here, through screening alkanol and alkanediol chemistries, 1,2-butanediol and pentanediol are unveiled as highly potent additives, which operate at a practical 1 volume% concentration owing to their ability to furnish dynamic solid-electrolyte interphase through pronounced interfacial filming. This unique mechanistic action renders effective corrosion and dendrite mitigation, resulting in up to five to twenty-fold zinc cyclability enhancement with a high Coulombic efficiency (up to 99.9%) and improved full-cell performance under demanding conditions, including at elevated temperatures. A machine learning-based analysis is presented to rationalize the additive performance relative to critical physicochemical descriptors, which can pave the way for a rational approach to efficient additive discoveries.

2.
Small ; 18(41): e2203222, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36094791

RESUMO

The practical application of Li-S batteries is severely limited due to low sulfur utilization, sluggish sulfur redox kinetics, intermediate polysulfide dissolution/shuttling, and subsequent anode degradation. A smart cathode with efficient electrocatalyst and a protected anode is necessary. Herein, hollow carbon (HC) spheres are used as a sulfur host to improve the electrical conductivity and buffer the volume expansion of active materials. Considering the weak interaction between carbon and lithium polysulfides (LiPS), tungsten diboride (WB2 ) nanoparticles are used as a conductive additive. Both experimental and density functional theory (DFT) comprehensively exhibit that metallic WB2 nanoparticles can firmly anchor the LiPS through B-S bond formation, accelerate their electrocatalytic conversion, and immobilize them. DFT also reveals that boron interacts with LiPS either through molecular or dissociative adsorption depending on its boron layer arrangement in WB2 . Further, a freestanding lithiated-poly(4-styrene sulfonate) membrane constructed on lithium, offers a homogeneous Li-ion flux, stable interface, and protection from LiPS. Finally, cells with the HC-S+WB2  cathode and protected anode exhibit improved active material utilization, superior rate performance, and impressive cycling stability, even at high sulfur loading and less quantity of the electrolyte. Further, the pouch cells demonstrate high reversible capacity and an excellent capacity retention.

6.
Am J Cardiovasc Drugs ; 20(4): 311-324, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32578167

RESUMO

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is now a global pandemic with the highest number of affected individuals in the modern era. Not only is the infection inflicting significant morbidity and mortality, but there has also been a significant strain to the health care system and the economy. COVID-19 typically presents as viral pneumonia, occasionally leading to acute respiratory distress syndrome (ARDS) and death. However, emerging evidence suggests that it has a significant impact on the cardiovascular (CV) system by direct myocardial damage, severe systemic inflammatory response, hypoxia, right heart strain secondary to ARDS and lung injury, and plaque rupture secondary to inflammation. Primary cardiac manifestations include acute myocarditis, myocardial infarction, arrhythmia, and abnormal clotting. Several consensus documents have been released to help manage CV disease during this pandemic. In this review, we summarize key cardiac manifestations, their management, and future implications.


Assuntos
Doenças Cardiovasculares/etiologia , Infecções por Coronavirus/complicações , Pandemias , Pneumonia Viral/complicações , COVID-19 , Doenças Cardiovasculares/patologia , Doenças Cardiovasculares/terapia , Infecções por Coronavirus/patologia , Infecções por Coronavirus/terapia , Humanos , Miocardite/virologia , Pneumonia Viral/patologia , Pneumonia Viral/terapia
7.
Oncotarget ; 11(13): 1097-1108, 2020 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-32284788

RESUMO

Glioblastoma (GBM) is the most common primary brain tumor and is invariably fatal. Heat shock proteins (HSPs) provide protein signatures/biomarkers for GBM that afford potential as targets for developing anti-GBM drugs. In GBM, elevated expression of hypoxia inducible factors under the influence of Ets family proteins significantly promotes the expression of HSPs. RNAseq analysis identified HSPB1 as a prominent upregulated HSP in GBM and in radiation resistant/temozolomide resistant (radio/TMZR) GBM. Here, we established friend leukemia integration 1 (Fli-1), a member of Ets family to be playing a transcriptional regulatory role on the HSPB1 gene. Fli-1 binds to nucleotide residues GGAA at binding sites 3, 6 and 7 in the 5-kb upstream region of HSPB1. Fli-1 has been linked to oncogenic transformation with upregulation in radio/TMZR GBM. Overexpression of Fli-1 in GBM promotes resistance, whereas Fli-1 knockdown in radio/TMZR GBM cells suppresses resistance. We identify the underlying molecular mechanisms of Fli-1-mediated regulation of HSPB1 that drive extracellular matrix remodeling and epithelial to mesenchymal transition in radio/TMZR GBM cells. This study uncovers Fli-1 as a potential therapeutic target for combating radiation and temozolomide resistance in GBM.

8.
Curr Hematol Malig Rep ; 14(4): 219-227, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31231778

RESUMO

PURPOSE OF REVIEW: To highlight recent results in targeting mRNA translation and discuss the results and prospects of translation inhibitors in cancer therapy. RECENT FINDINGS: Until recently, inhibitors of mRNA translation have been thought to likely lack a therapeutic window. In 2012, the Food and Drug Administration (FDA) approved omacetaxine mepesuccinate (homoharringtonine) for the treatment of adults with chronic myelogenous leukemia (CML) who are resistant to at least two tyrosine kinase inhibitors. Since then, a few drugs, notably tomivosertib (eFT-508), selinexor (KPT-330), and ribavirin, have entered clinical trials. These drugs are known to inhibit mRNA translation. More recently, a number of interesting studies report that discrete subsets of proteins in cancer cells may be selectively targeted at the translation step, through inhibiting signals such as phospho-4E-BP1, eIF4A, and eIF4E. Promising therapies using these strategies have demonstrated potent anti-tumor activity in preclinical cancer models. The growing number of translation inhibitors with diverse mechanisms, coupled with emerging insights into translational regulation of different cancer-promoting genes, suggests a bright new horizon for the field of therapeutic targeting of mRNA translation in cancer.


Assuntos
Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Terapia de Alvo Molecular , Neoplasias/tratamento farmacológico , Neoplasias/genética , Biossíntese de Proteínas/efeitos dos fármacos , RNA Mensageiro/genética , Animais , Biomarcadores , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias/metabolismo , Transdução de Sinais/efeitos dos fármacos
9.
Biochim Biophys Acta Gen Subj ; 1863(7): 1196-1209, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31028823

RESUMO

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.


Assuntos
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 , Humanos
10.
Cancer Lett ; 452: 254-263, 2019 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-30904616

RESUMO

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.


Assuntos
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/metabolismo
11.
Oncogene ; 37(33): 4546-4561, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29743594

RESUMO

Although there is a strong correlation between multinucleated cells (MNCs) and cancer chemo-resistance in variety of cancers, our understanding of how multinucleated cells modulate the tumor micro-environment is limited. We captured multinucleated cells from triple-negative chemo-resistant breast cancers cells in a time frame, where they do not proliferate but rather significantly regulate their micro-environment. We show that oxidatively stressed MNCs induce chemo-resistance in vitro and in vivo by secreting VEGF and MIF. These factors act through the RAS/MAPK pathway to induce chemo-resistance by upregulating anti-apoptotic proteins. In MNCs, elevated reactive oxygen species (ROS) stabilizes HIF-1α contributing to increase production of VEGF and MIF. Together the data indicate, that the ROS-HIF-1α signaling axis is very crucial in regulation of chemo-resistance by MNCs. Targeting ROS-HIF-1α in future may help to abrogate drug resistance in breast cancer.


Assuntos
Resistencia a Medicamentos Antineoplásicos/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Neoplasias de Mama Triplo Negativas/metabolismo , Mama/metabolismo , Linhagem Celular Tumoral , Feminino , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Fatores Inibidores da Migração de Macrófagos/metabolismo , Transdução de Sinais/fisiologia , Microambiente Tumoral/fisiologia , Fator A de Crescimento do Endotélio Vascular/metabolismo
13.
Cell Signal ; 35: 24-36, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28347875

RESUMO

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.


Assuntos
Antígeno 96 de Linfócito/genética , Neoplasias/tratamento farmacológico , Neovascularização Patológica/tratamento farmacológico , Peptídeos Cíclicos/administração & dosagem , Receptor 4 Toll-Like/genética , Bacillus megaterium/química , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana , Humanos , Quinase I-kappa B/genética , Antígeno 96 de Linfócito/química , Fator 88 de Diferenciação Mieloide/genética , NF-kappa B/genética , Invasividade Neoplásica/genética , Neoplasias/genética , Neoplasias/patologia , Neovascularização Patológica/genética , Neovascularização Patológica/patologia , Peptídeos Cíclicos/química , RNA Interferente Pequeno/genética , Transdução de Sinais/efeitos dos fármacos , Receptor 4 Toll-Like/química
14.
Acta Pharmacol Sin ; 38(5): 591-613, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28317871

RESUMO

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/métodos
15.
Cancer Lett ; 388: 292-302, 2017 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-28025102

RESUMO

Selective targeting to the tumor niche remains a major challenge in successful cancer therapy. Somatostatin receptor 2 (SSTR2) is overexpressed in breast cancer cells thus making this receptor an attractive target for selective guidance of ligand-conjugated drug liposomes to the tumor site. In this study, a synthetic somatostatin analogue (SST) was used as SSTR2 targeting agent and Diacerein was employed as therapeutic molecule. Diacerein loaded liposomes (DNL) were prepared and they were further decorated with the synthetic and stable analogue of somatostatin (SST-DNL). Fabricated liposomes were nano-size in range and biocompatible. SST-DNL displayed significantly better anti-tumor efficacy as compared to free Diacerein (DN) and DNL in breast cancer models. Enhanced apoptosis in breast cancer cells was detected in SST-DNL treated groups as monitored by cell cycle analysis and changes in expression level of apoptotic/anti-apoptotic proteins Bcl-2, Bax, cleaved Caspase 3 and PARP. SST-DNL more effectively inhibited the oncogenic IL-6/IL-6R/STAT3/MAPK/Akt signalling pathways as compared to DN or DNL in cancer cells. In addition, SST-DNL effectively suppressed angiogenesis and cancer cell invasion. In vivo tumor growth in a MDA-MB-231 mouse xenograft model was significantly suppressed following SST-DNL treatment. In xenograft model, immunohistochemistry of Ki-67 and CD-31 indicated that SST-DNL improved the anti-proliferative and anti-angiogenic impacts of Diacerein. In vivo pharmacokinetic studies in rats showed enhanced circulation time in the DNL or SST-DNL treated groups as compared to free DN. Considering all of these findings, we conclude that SST-DNL provides a novel strategy with better efficacy for breast cancer therapy.


Assuntos
Antraquinonas/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Lipossomos/metabolismo , Receptores de Somatostatina/metabolismo , Animais , Antraquinonas/farmacologia , Anti-Inflamatórios/farmacologia , Feminino , Humanos , Interleucina-6 , Camundongos , Camundongos Nus
16.
Biochim Biophys Acta Gen Subj ; 1861(1 Pt A): 3039-3052, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27721046

RESUMO

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 X
17.
Tumour Biol ; 37(5): 6389-402, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26631035

RESUMO

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.


Assuntos
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 radiação
19.
Eur J Pharmacol ; 765: 217-27, 2015 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-26306675

RESUMO

BI-69A11, novel Akt inhibitor, is currently drawing much attention due to its intriguing effect in inducing apoptosis in melanoma, breast, prostate and colon cancer. However, earlier reports reveal that PI3K/Akt/mTOR inhibitors promote autophagy at the early stage as a survival mechanism that might affect its apoptotic potential. It is necessary to investigate whether BI-69A11 mediated apoptosis is associated with autophagy for enhancing its therapeutic efficacy. Here, we found that BI-69A11 induced autophagy at earlier time point through the inhibition of Akt/mTOR/p70S6kinase pathway. Dose-dependent and time-dependent conversion of LC3-I to LC3-II, increased accumulation of LC3-GFP dots in cytoplasm and increase in other autophagic markers such as Beclin-1, firmly supported the fact that BI-69A11 induces autophagy. Atg5, Atg7 and Beclin-1 siRNA mediated genetic attenuation and pre-treatment with pharmacological inhibitor 3-MA and CQ diminished the autophagy and increased the propensity of cell death towards apoptosis. It was also suggested that BI-69A11 mediated interaction between Akt, HSP-90 and Beclin-1 maintained the fine balance between autophagy and apoptosis. Interaction between Beclin-1 and HSP90 is one of the prime causes of induction of autophagy. Here, we also generated a novel combination therapy by pretreatment with CQ that inhibited the autophagy and accelerated the apoptotic potential of BI-69A11. In summary; our findings suggest that induction of autophagy lead to the resistance of colon cancer towards BI-69A11 mediated apoptosis.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Benzimidazóis/farmacologia , Neoplasias do Colo/patologia , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Quinolonas/farmacologia , Ciclo Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cloroquina/farmacologia , Neoplasias do Colo/metabolismo , Sinergismo Farmacológico , Células HCT116 , Células HT29 , Humanos , Proteínas Proto-Oncogênicas c-akt/genética , Transdução de Sinais/efeitos dos fármacos , Transfecção
20.
Cancer Cell Int ; 15: 74, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26225121

RESUMO

BACKGROUND: Squamous cell carcinoma of the oral cavity (SCCOC) is the dominant origin of cancer associated mortality. Previous findings by our study reported that acquisition of anoikis resistance has a significant role in tumor progression of oral cavity. Several genes were over-expressed in anoikis-resistant cells under detached conditions which we confirmed earlier by microarray. Normal oral squamous epithelia grow adherent to a basement membrane, and when detached from the extracellular matrix, undergoes programmed cell death. The acquisition of anoikis-resistance is crucial phenomena in oral tumor advancement. In the current study, we have identified S100A7 expression as contributing factor for anoikis resistance and tumorigenicity in human oral cancer cells. Further, we have explored that elevated S100A7 expression in anoikis-sensitive oral keratinocytes and cancer cells reshape them more resistant to anoikis and apoptosis inducers via activation of cellular intrinsic and extrinsic avenue. METHODS: A subset of human cancer cell lines TU167, JMAR, JMARC39, JMARC42 and MDA-MB-468 were utilized for the generation of resistant stable cell lines. Further, immunohistochemistry, western blot and immunoprecipitation, assays of apoptosis, soft agar assay, orthotopic animal model and signaling elucidation were performed to establish our hypothesis. RESULTS: S100A7 gene is found to be responsible for anoikis resistance and tumorigenicity in human oral cancer cells. We have observed up-regulation of S100A7 in anoikis resistant cell lines, orthotropic model and patients samples with head and neck cancer. It is also noticed that secretion of S100A7 protein in conditioned medium by anoikis resistant head & neck cancer cell and in saliva of head and neck cancer patients. Up-regulation of S100A7 expression has triggered enhanced tumorigenicity and anchorage-independent growth of cancer cells through Akt phosphorylation leading to development of aniokis resistance in head and neck cancer cells. CONCLUSIONS: These data have led us to conclude that S100A7 is the major contributing factor in mediating anoikis-resistance of oral cancer cells and local tumor progression, and S100A7 might be useful as diagnostic marker for early detection of primary and recurrent squamous cell cancer.

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