Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 12.065
Filtrar
1.
Anticancer Res ; 40(9): 4937-4946, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32878782

RESUMO

BACKGROUND/AIM: ALK inhibitors like Crizotinib, Ceritinib and Alectinib are targeted therapies used in patients with anaplastic lymphoma kinase (ALK)-positive, advanced non-small cell lung cancer (NSCLC). Since in this tumor entity radiotherapy is employed sequentially or concomitantly, potential synergistic effects were investigated, which may support the hypothesis of induced radiosensitization by using ALK inhibitors. MATERIALS AND METHODS: Two cell lines expressing wild-type (WT) or echinoderm microtubule-associated protein-like 4 (EML4)-ALK were treated with ALK inhibitors, followed by irradiation. Cell survival, cell death, cell cycle and phosphorylation of H2A histone family, member X (H2AX) were examined. RESULTS: Combined treatment with ALK-inhibitors plus 10 Gy-irradiation led to effects similar to those of sole radiotherapy, but was more effective than sole drug treatment. CONCLUSION: There is no clear evidence of sensitization to radiation by treating EML4-ALK mutated cells with ALK inhibitors.


Assuntos
Quinase do Linfoma Anaplásico/antagonistas & inibidores , Antineoplásicos/farmacologia , Carcinoma Pulmonar de Células não Pequenas/terapia , Neoplasias Pulmonares/terapia , Proteínas de Fusão Oncogênica/genética , Inibidores de Proteínas Quinases/farmacologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Ciclo Celular/efeitos da radiação , Morte Celular/efeitos dos fármacos , Morte Celular/efeitos da radiação , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Quimiorradioterapia , Resistencia a Medicamentos Antineoplásicos/genética , Humanos , Neoplasias Pulmonares/patologia , Mutação
2.
Anticancer Res ; 40(9): 5001-5013, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32878788

RESUMO

AIM: Newly synthesized platinum(IV) complexes with ethylenediamine-N,N'-diacetate ligands (EDDA-type) (butyl-Pt and pentyl-Pt) were investigated against two cancer (A549 lung, and HTB 140 melanoma) and one non-cancerous (MRC-5 embryonic lung fibroblast) human cell lines. MATERIALS AND METHODS: The effects of these agents were compared with those of cisplatin after 6-, 24- and 48-h treatment. Sulforhodamine-B (SRB) assay was performed to estimate the cytotoxic effect, while the inhibitory effect on cell proliferation was measured using 5-bromo-2,-deoxyuridine (BrdU) incorporation assay. Cell cycle analysis was performed by flow cytometry. Type of cell death induced by these agents was determined by electrophoretic analysis of DNA, flow cytometry and by western blot analysis of proteins involved in induction of apoptosis. The effects of gamma irradiation, alone and in combination with platinum-based compounds, were examined by clonogenic and SRB assays. RESULTS: All examined platinum-based compounds had inhibitory and antiproliferative effects on A549 cells, but not on HTB140 and MRC-5 cells. Butyl-Pt, pentyl-Pt and cisplatin arrested the cell cycle in the S-phase and induced apoptotic cell death via regulation of expression of B-cell lymphoma 2 (BCL2) and BCL2-associated X (BAX) proteins. Platinum-based compounds increased the sensitivity of A549 cells to gamma irradiation. Butyl-Pt and pentyl-Pt showed better antitumour effects against A549 cells than did cisplatin, by interfering in cell proliferation and the cell cycle, and by triggering apoptosis. CONCLUSION: The effects of gamma irradiation on tumour cells may be amplified by pre-treatment of cells with platinum-based compounds.


Assuntos
Antineoplásicos/farmacologia , Compostos Organoplatínicos/farmacologia , Radiossensibilizantes/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Cisplatino/farmacologia , Relação Dose-Resposta a Droga , Ácido Edético/análogos & derivados , Ácido Edético/química , Raios gama , Humanos , Concentração Inibidora 50 , Compostos Organoplatínicos/síntese química , Compostos Organoplatínicos/química , Radiossensibilizantes/síntese química , Radiossensibilizantes/química
3.
Anticancer Res ; 40(9): 5151-5158, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32878803

RESUMO

BACKGROUND/AIM: Magnetic stimulation is used in the treatment of a diversity of diseases, but a complete understanding of the underlying mechanisms of action requires further investigation. We examined the effect of static magnetic stimulation (SMS) in different cell lines. MATERIALS AND METHODS: A culture plate holder with attached NeFeB magnets was developed. Different magnetic field intensities and periods were tested in tumoral and non-tumoral cell lines. To verify the cellular responses to SMS, cell viability, cell death, cell cycle and BDNF expression were evaluated. RESULTS: Exposure of SH-SY5Y cells to SMS for 24 hours led to a decrease in cell viability. Analysis 24 h after stimulation revealed a decrease in apoptotic and double-positive cells, associated with an increase in the number of necrotic cells. CONCLUSION: The effects of SMS on cell viability are cell type-specific, inducing a decrease in cell viability in SH-SY5Y cells. This suggests that SMS may be a potential tool in the treatment of neuronal tumors.


Assuntos
Sobrevivência Celular/efeitos da radiação , Fenômenos Magnéticos , Apoptose/efeitos da radiação , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Ciclo Celular/efeitos da radiação , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Humanos , Neuroblastoma/genética , Neuroblastoma/metabolismo , Especificidade de Órgãos/efeitos da radiação
4.
Anticancer Res ; 40(10): 5497-5502, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32988872

RESUMO

BACKGROUND/AIM: The cell-killing and radiosensitizing effects of carbon-ion (C-ion) beams with low linear energy transfer (LET) are underexplored. We aimed to demonstrate the cell-killing effects of 60Co gamma rays and C-ion beams at various LET values and the radiosensitizing effect of C-ion beams at various LET and cisplatin levels. MATERIALS AND METHODS: Human uterine cervical cancer cells were irradiated with 60Co gamma rays and C-ion beams at different levels of LET, with and without cisplatin treatment. RESULTS: Low-LET C-ion beams had a superior cell-killing effect compared to 60Co gamma rays. Survival curves under low-LET C-ion beams were more similar to that of 60Co gamma rays than that of high-LET C-ion beams. Cisplatin significantly reduced cell survival after 1, 2, and 3 Gy C-ion beam irradiations at LET values of 13/30/70 keV/µm, 13/30 keV/µm, and 13 keV/µm, respectively. CONCLUSION: Low-LET C-ion beams combined with cisplatin have higher radiosensitizing effects than high-LET C-ion beams.


Assuntos
Carbono/uso terapêutico , Radioisótopos de Cobalto/uso terapêutico , Radiossensibilizantes/uso terapêutico , Neoplasias do Colo do Útero/radioterapia , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Cisplatino/farmacologia , Relação Dose-Resposta à Radiação , Feminino , Raios gama , Humanos , Transferência Linear de Energia/efeitos da radiação , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/patologia
5.
Nat Commun ; 11(1): 4116, 2020 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-32807793

RESUMO

Glioblastoma contains a rare population of self-renewing brain tumor stem cells (BTSCs) which are endowed with properties to proliferate, spur the growth of new tumors, and at the same time, evade ionizing radiation (IR) and chemotherapy. However, the drivers of BTSC resistance to therapy remain unknown. The cytokine receptor for oncostatin M (OSMR) regulates BTSC proliferation and glioblastoma tumorigenesis. Here, we report our discovery of a mitochondrial OSMR that confers resistance to IR via regulation of oxidative phosphorylation, independent of its role in cell proliferation. Mechanistically, OSMR is targeted to the mitochondrial matrix via the presequence translocase-associated motor complex components, mtHSP70 and TIM44. OSMR interacts with NADH ubiquinone oxidoreductase 1/2 (NDUFS1/2) of complex I and promotes mitochondrial respiration. Deletion of OSMR impairs spare respiratory capacity, increases reactive oxygen species, and sensitizes BTSCs to IR-induced cell death. Importantly, suppression of OSMR improves glioblastoma response to IR and prolongs lifespan.


Assuntos
Glioblastoma/metabolismo , Células-Tronco Neoplásicas/metabolismo , Radiação Ionizante , Receptores de Oncostatina M/metabolismo , Animais , Morte Celular/efeitos da radiação , Linhagem Celular Tumoral , Proliferação de Células/efeitos da radiação , Sobrevivência Celular/efeitos da radiação , Células Cultivadas , Imunofluorescência , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Humanos , Masculino , Camundongos , Camundongos SCID , NADH Desidrogenase/genética , NADH Desidrogenase/metabolismo , Células-Tronco Neoplásicas/efeitos da radiação , Oncostatina M/metabolismo , Estresse Oxidativo/efeitos da radiação , Receptores de Oncostatina M/genética , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais/efeitos da radiação
6.
Life Sci ; 257: 118087, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32702442

RESUMO

AIMS: Recent studies suggest that direct exposure of cells to fractionated radiotherapy might induce radioresistance. However, the effects of fractionated radiotherapy on the non-irradiated bystander cells remain unclear. We hypothesized that fractionated radiotherapy could enhance radioresistance and proliferation of bystander cells. MAIN METHODS: Human tumor cell lines, including A549 and HT29 were irradiated (2 Gy per day). The irradiated cells (either A549 or HT29) were co-cultured with non-irradiated cells of the same line using transwell co-culture system. Tumor cell proliferation, radioresistance and apoptosis were measured using MTT assay, clonogenic survival assay and Annexin-V in bystander cells, respectively. In addition, activation of Chk1 (Ser 317), Chk2 (Thr 68) and Akt (Ser473) were measured via western blot. KEY FINDINGS: Irradiated HT29 cells induced conventional bystander effects detected as modulation of clonogenic survival parameters (decreased area under curve, D10 and ED50 and increased α) and proliferation in recipient neighbors. While, irradiated A549 cells significantly enhanced the radioresistance and proliferation of bystander cells. These changes were accompanied with enhanced activation of Chk1, Chk2 and Akt in non-irradiated bystander A549 cells. Moreover, both bystander effects (damaging and protective) were mediated through secreted factors. SIGNIFICANCE: These findings suggest that fractionated radiotherapy could promote proliferation and radioresistance of bystander cells probably through survival and proliferation pathways.


Assuntos
Apoptose/efeitos da radiação , Efeito Espectador/efeitos da radiação , Proliferação de Células/efeitos da radiação , Tolerância a Radiação/efeitos da radiação , Células A549 , Sobrevivência Celular/efeitos da radiação , Técnicas de Cocultura , Células HT29 , Humanos
7.
PLoS One ; 15(7): e0236199, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32673355

RESUMO

Antimicrobial-resistant and novel pathogens continue to emerge, outpacing efforts to contain and treat them. Therefore, there is a crucial need for safe and effective therapies. Ultraviolet-A (UVA) phototherapy is FDA-approved for several dermatological diseases but not for internal applications. We investigated UVA effects on human cells in vitro, mouse colonic tissue in vivo, and UVA efficacy against bacteria, yeast, coxsackievirus group B and coronavirus-229E. Several pathogens and virally transfected human cells were exposed to a series of specific UVA exposure regimens. HeLa, alveolar and primary human tracheal epithelial cell viability was assessed after UVA exposure, and 8-Oxo-2'-deoxyguanosine was measured as an oxidative DNA damage marker. Furthermore, wild-type mice were exposed to intracolonic UVA as an in vivo model to assess safety of internal UVA exposure. Controlled UVA exposure yielded significant reductions in Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Enterococcus faecalis, Clostridioides difficile, Streptococcus pyogenes, Staphylococcus epidermidis, Proteus mirabilis and Candida albicans. UVA-treated coxsackievirus-transfected HeLa cells exhibited significantly increased cell survival compared to controls. UVA-treated coronavirus-229E-transfected tracheal cells exhibited significant coronavirus spike protein reduction, increased mitochondrial antiviral-signaling protein and decreased coronavirus-229E-induced cell death. Specific controlled UVA exposure had no significant effect on growth or 8-Oxo-2'-deoxyguanosine levels in three types of human cells. Single or repeated in vivo intraluminal UVA exposure produced no discernible endoscopic, histologic or dysplastic changes in mice. These findings suggest that, under specific conditions, UVA reduces various pathogens including coronavirus-229E, and may provide a safe and effective treatment for infectious diseases of internal viscera. Clinical studies are warranted to further elucidate the safety and efficacy of UVA in humans.


Assuntos
Infecções Bacterianas/terapia , Micoses/terapia , Infecções Oportunistas/terapia , Terapia Ultravioleta/métodos , Viroses/terapia , Animais , Apoptose/efeitos da radiação , Bactérias/efeitos da radiação , Infecções Bacterianas/microbiologia , Sobrevivência Celular/efeitos da radiação , Colo/microbiologia , Colo/efeitos da radiação , Coronavirus Humano 229E/efeitos da radiação , Dano ao DNA/efeitos da radiação , Modelos Animais de Doenças , Enterovirus Humano B/efeitos da radiação , Feminino , Células HeLa , Humanos , Mucosa Intestinal/microbiologia , Mucosa Intestinal/efeitos da radiação , Masculino , Camundongos , Micoses/microbiologia , Infecções Oportunistas/microbiologia , Cultura Primária de Células , Terapia Ultravioleta/efeitos adversos , Viroses/virologia , Leveduras/efeitos da radiação
8.
Prostate ; 80(12): 986-992, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32557725

RESUMO

BACKGROUND: Focal therapies for prostate cancer (PC) can reduce adverse events and do not lead to androgen-independent progression. Ultrasound could be used for cancer treatments if the repetition frequency is fitted to the purpose. We investigated the possible therapeutic effect of ultrasound irradiation on PC cells. MATERIALS AND METHODS: We irradiated two PC cell lines, androgen-dependent LNCaP and -independent PC-3 with ultrasound (3.0 W/cm2 , 3 MHz, irradiation time rate: 20%) for 2 minutes for 1 day or 3 consecutive days at a repetition frequency of 1, 10, or 100 Hz in vitro. Cell proliferation and apoptosis were determined after irradiation. RESULTS: Cell proliferation of PC-3 was significantly inhibited after 1 day (P < .0001) and 3 days (P < .0001) of 10 Hz ultrasound irradiation, and that of LNCaP after 1 day (P < .0001) and 3 days (P < .0001) of irradiation. LNCaP was more sensitive to ultrasound at both lower and higher cell density but PC-3 was only sensitive at a lower cell density (P < .01). Irradiation with 10 Hz ultrasound-induced significantly more PC-3 apoptotic cells than control (1 day, P = .0137; 3 days, P = .0386) rather than irradiation with 1 Hz. Apoptosis via caspase-3 was induced at 10 Hz in 1-day (P < .05) irradiation in both cell lines. CONCLUSIONS: Ultrasound irradiation with even 1 day of 10 Hz significantly inhibited cell proliferation in both LNCaP and PC-3, especially by the remarkable induction of apoptosis in vitro. Our study indicated that ultrasound irradiation can be a therapeutic option for PC and further studies in vivo will be undertaken.


Assuntos
Neoplasias da Próstata/radioterapia , Terapia por Ultrassom/métodos , Apoptose/efeitos da radiação , Linhagem Celular Tumoral , Proliferação de Células/efeitos da radiação , Sobrevivência Celular/efeitos da radiação , Humanos , Masculino , Células PC-3 , Neoplasias da Próstata/patologia , Neoplasias de Próstata Resistentes à Castração/patologia , Neoplasias de Próstata Resistentes à Castração/radioterapia
9.
Lasers Med Sci ; 35(8): 1841-1848, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32483748

RESUMO

Photobiomodulation (PBM) has been used to modulate the inflammatory and immune responses, pain relief, and to promote wound healing. PBM is widely used in dental practice and its cellular effects should be investigated. The aim was to evaluate if PBM changes proteins cell death-related, such as caspase-6 and Bcl-2, in periodontal ligament cells. Eighteen mice were divided in three groups (n = 6), i.e., (I) control, (II) 3 J cm-2, and (III) 30 J cm-2. Low power infrared laser (830 nm) parameters were power at 10 mW, energy densities at 3 and 30 J cm-2 in continuous emission mode, exposure time of 15 and 150 s, respectively for 4 days in a row. Twenty-four hours after last irradiation, the animals were euthanized, and their jaws were fixed and decalcified. Caspase-6 and Bcl-2 were analyzed by real-time polymerase chain reaction and immunocytochemical techniques, and DNA fragmentation was evaluated by TUNEL. Statistical differences were not significant to caspase-6 mRNA relative levels in tissues from jaws at both energy densities, but a significant increase of Bcl-2 mRNA relative levels was obtained at 30 J cm-2 group. Also, 30 J cm-2 group showed caspase-6 positive-labeled cells decreased and Bcl-2 positive-labeled cells significantly increased. TUNEL-labeled cells demonstrated DNA fragmentation decreased at 30 J cm-2. PBM can alter Bcl-2 mRNA relative level and both caspase-6 and Bcl-2 protein, modulating cell survival, as well as to reduce DNA fragmentation. More studies must be performed in order to obtain conclusive results about photobiostimulation effects using infrared low-level laser in apoptosis process as to achieve the optimum dosage.


Assuntos
Apoptose/efeitos da radiação , Terapia com Luz de Baixa Intensidade , Ligamento Periodontal/citologia , Animais , Sobrevivência Celular/efeitos da radiação , Fragmentação do DNA/efeitos da radiação , Regulação da Expressão Gênica/efeitos da radiação , Camundongos , Proteínas Proto-Oncogênicas c-bcl-2/genética , RNA Mensageiro/genética , Cicatrização/efeitos da radiação
10.
Br J Radiol ; 93(1112): 20190949, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32464080

RESUMO

OBJECTIVES: The relative biological effectiveness (RBE) of X-rays and γ radiation increases substantially with decreasing beam energy. This trend affects the efficacy of medical applications of this type of radiation. This study was designed to develop a model based on a survey of experimental data that can reliably predict this trend. METHODS: In our model, parameters α and ß of a cell survival curve are simple functions of the frequency-average linear energy transfer (LF) of delta electrons. The choice of these functions was guided by a microdosimetry-based model. We calculated LF by using an innovative algorithm in which LF is associated with only those electrons that reach a sensitive-to-radiation volume (SV) within the cell. We determined model parameters by fitting the model to 139 measured (α,ß) pairs. RESULTS: We tested nine versions of the model. The best agreement was achieved with [Formula: see text] and ß being linear functions of [Formula: see text] .The estimated SV diameter was 0.1-1 µm. We also found that α, ß, and the α/ß ratio increased with increasing [Formula: see text] . CONCLUSIONS: By combining an innovative method for calculating [Formula: see text] with a microdosimetric model, we developed a model that is consistent with extensive experimental data involving photon energies from 0.27 keV to 1.25 MeV. ADVANCES IN KNOWLEDGE: We have developed a photon RBE model applicable to an energy range from ultra-soft X-rays to megaelectron volt γ radiation, including high-dose levels where the RBE cannot be calculated as the ratio of α values. In this model, the ionization density represented by [Formula: see text] determines the RBE for a given photon spectrum.


Assuntos
Sobrevivência Celular/efeitos da radiação , Raios gama , Modelos Estatísticos , Raios X , Animais , Linhagem Celular , Cricetulus , Relação Dose-Resposta à Radiação , Fibroblastos/efeitos da radiação , Humanos , Camundongos , Doses de Radiação
11.
Cancer Radiother ; 24(3): 247-257, 2020 Jun.
Artigo em Francês | MEDLINE | ID: mdl-32220563

RESUMO

In radiotherapy, the dose prescription is currently based on discretized dose-effects records that do not take into fully account for the complexity of the patient-dose-response relationship. Their predictive performance on both anti-tumour efficacy and toxicity can be optimized by integrating radiobiological models. It is with this in mind that the calculation models TCP (Tumor Control Probability) and NTCP (Normal Tissue Complication Probability) have been developed. Their construction involves several important steps that are necessary and important to understand. The first step is based on radiobiological models allowing to calculate according to more or less complexity the rate of surviving cells after irradiation. Two additional steps are required to convert the physical dose into an equivalent biological dose, in particular a 2Gy equivalent biological dose (EQD2): first to take into account the effect of the fractionation of the dose for both the target volume and the organs at risk; second to convert an heterogeneous dose to an organ into an homogeneous dose having the same effect (Niemierko generalized equivalent uniform dose (gEUD)). Finally, the process of predicting clinical effects based on radiobiological models transform doses into tumour control (TCP) or toxicity (NTCP) probabilities using parameters that reflect the radiobiological characteristics of the tissues in question. The use of these models in current practice is still limited, but since the radiotherapy softwares increasingly integrate them, it is important to know the principle and limits of application of these models.


Assuntos
Sobrevivência Celular/efeitos da radiação , Modelos Biológicos , Radiobiologia , Relação Dose-Resposta à Radiação , Humanos , Órgãos em Risco/efeitos da radiação , Probabilidade , Dosagem Radioterapêutica , Eficiência Biológica Relativa
12.
Radiat Res ; 193(6): 520-530, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32216710

RESUMO

Genetic and epigenetic profile changes associated with individual radiation sensitivity are well documented and have led to enhanced understanding of the mechanisms of the radiation-induced DNA damage response. However, the search continues to identify reliable biomarkers of individual radiation sensitivity. Herein, we report on a multi-biomarker approach using traditional cytogenetic biomarkers, DNA damage biomarkers and transcriptional microRNA (miR) biomarkers coupled with their potential gene targets to identify radiosensitivity in ataxia-telangiectasia mutated (ATM)-deficient lymphoblastoid cell lines (LCL); ATM-proficient cell lines were used as controls. Cells were 0.05 and 0.5 Gy irradiated, using a linear accelerator, with sham-irradiated cells as controls. At 1 h postirradiation, cells were fixed for γ-H2AX analysis as a measurement of DNA damage, and cytogenetic analysis using the G2 chromosomal sensitivity assay, G-banding and FISH techniques. RNA was also isolated for genetic profiling by microRNA (miR) and RT-PCR analysis. A panel of 752 miR were analyzed, and potential target genes, phosphatase and tensin homolog (PTEN) and cyclin D1 (CCND1), were measured. The cytogenetic assays revealed that although the control cell line had functional cell cycle checkpoints, the radiosensitivity of the control and AT cell lines were similar. Analysis of DNA damage in all cell lines, including an additional control cell line, showed elevated γ-H2AX levels for only one AT cell line. Of the 752 miR analyzed, eight miR were upregulated, and six miR were downregulated in the AT cells compared to the control. Upregulated miR-152-3p, miR-24-5p and miR-92-15p and all downregulated miR were indicated as modulators of PTEN and CCDN1. Further measurement of both genes validated their potential role as radiation-response biomarkers. The multi-biomarker approach not only revealed potential candidates for radiation response, but provided additional mechanistic insights into the response in AT-deficient cells.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/deficiência , Ciclina D1/metabolismo , Linfócitos/metabolismo , Linfócitos/efeitos da radiação , MicroRNAs/genética , PTEN Fosfo-Hidrolase/metabolismo , Biomarcadores/metabolismo , Linhagem Celular , Proliferação de Células/efeitos da radiação , Sobrevivência Celular/efeitos da radiação , Dano ao DNA , Regulação da Expressão Gênica/efeitos da radiação , Humanos , Linfócitos/citologia
13.
PLoS One ; 15(3): e0229272, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32119704

RESUMO

BACKGROUND AND AIMS: Radiotherapy is one of the major remedies for the treatment of cancer, including nasopharyngeal carcinoma (NPC). Radioresistance occurs very often in target cells that is a large drawback in cancer treated with radiotherapy. Livin involves the over-growth of cancer cells. This study aims to investigate the role of livin in the radioresistance formation in NPC cells. METHODS: NPC cell lines were exposed to small doses of irradiation to establish a cell model of radioresistance, in which the role of livin in the development of radioresistance was evaluated. RESULTS: The expression of livin was observed in NPC cells, which was significantly increased after exposing to small doses of irradiation. A negative correlation was detected between livin and Fas expression in NPC cells. Livin formed a complex with heat shock factor-1 (HSF1, the transcription factor of Fas) in NPC cells after irradiation, which sped up ubiquitination of HSF1. Livin was involved in suppressing Fas expression in NPC cells with radioresistance. Exposure to livin inhibitors prevented radioresistance development and overcame the established radioresistance in NPC cells. CONCLUSIONS: Livin expression in NPC cells plays a critical role in the development of radioresistance. Depletion of livin increases the sensitiveness of NPC cells to irradiation. Target therapy against livin may have the translational potential for the treatment of NPC.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Inibidoras de Apoptose/genética , Proteínas Inibidoras de Apoptose/metabolismo , Carcinoma Nasofaríngeo/metabolismo , Neoplasias Nasofaríngeas/metabolismo , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Tolerância a Radiação , Regulação para Cima , Proteínas Adaptadoras de Transdução de Sinal/antagonistas & inibidores , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Fatores de Transcrição de Choque Térmico/metabolismo , Humanos , Proteínas Inibidoras de Apoptose/antagonistas & inibidores , Carcinoma Nasofaríngeo/genética , Carcinoma Nasofaríngeo/radioterapia , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/radioterapia , Proteínas de Neoplasias/antagonistas & inibidores , Peptídeos/farmacologia , Tolerância a Radiação/efeitos dos fármacos , Transdução de Sinais , Ubiquitinação , Regulação para Cima/efeitos dos fármacos , Receptor fas/metabolismo
14.
Radiat Res ; 193(5): 451-459, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32150497

RESUMO

Findings from previous studies have suggested that the telomerase system is involved in radiation-induced genomic instability. In this study, we investigated the involvement of telomerase in the development and processing of chromosomal damage at different cell cycle stages after irradiation of human fibroblasts. Several response criteria were investigated, including cell survival, chromosomal damage (using the micronucleus assay), G2-induced chromatid aberrations (using the conventional G2 assay as well as a chemically-induced premature chromosome condensation assay) and DNA double-strand breaks (DSBs; using γ-H2AX, 53BP1 and Rad51) in an isogenic pair of cell lines: BJ human foreskin fibroblasts and BJ1-hTERT, a telomerase-immortalized BJ cell line. To distinguish among G1, S and G2 phase, cells were co-immunostained for CENP-F and cyclin A, which are tightly regulated proteins in the cell cycle. After X-ray irradiation at doses in the range of 0.1-6 Gy, the results showed that for cell survival and micronuclei induction, where the overall effect is dominated by the cells in G1 and S phase, no difference was observed between the two cell types; in contrast, when radiation sensitivity at the G2 stage of the cell cycle was analyzed, a significantly higher number of chromatid-type aberrations (breaks and exchanges), and higher levels of γ-H2AX and of Rad51 foci were observed for the BJ cells compared to the BJ1-hTERT cells. Therefore, it can be concluded that telomerase appears to be involved in DNA DSB repair processes, mainly in the G2 phase. These data, taken overall, reinforce the notion that hTERT or other elements of the telomere/telomerase system may defend chromosome integrity in human fibroblasts by promoting repair in G2 phase of the cell cycle.


Assuntos
Instabilidade Genômica/efeitos da radiação , Telomerase/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos da radiação , Fibroblastos/citologia , Fibroblastos/metabolismo , Fibroblastos/efeitos da radiação , Fase G2/efeitos da radiação , Raios gama/efeitos adversos , Humanos , Testes para Micronúcleos , Rad51 Recombinase/metabolismo , Fase S/efeitos da radiação
15.
J Opt Soc Am A Opt Image Sci Vis ; 37(2): 346-352, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32118916

RESUMO

Digital holographic microscopy supplemented with the developed cell segmentation and machine learning and classification algorithms is implemented for quantitative description of the dynamics of cellular necrosis induced by photodynamic treatment in vitro. It is demonstrated that the developed algorithms operating with a set of optical, morphological, and physiological parameters of cells, obtained from their phase images, can be used for automatic distinction between live and necrotic cells. The developed classifier provides high accuracy of about 95.5% and allows for calculation of survival rates in the course of cell death.


Assuntos
Holografia , Aprendizado de Máquina , Microscopia , Necrose/diagnóstico por imagem , Sobrevivência Celular/efeitos da radiação , Células HeLa , Humanos , Processamento de Imagem Assistida por Computador
16.
J Photochem Photobiol B ; 204: 111587, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32062387

RESUMO

Although the photothermal therapy (PTT) has achieved tremendous progress in the recent times, still it has to improve an extensive way to achieve the efficient targeted photothermal removal of the tumor cells. Owing to this requirement, we demonstrated a novel class of reduced graphene oxide based photothermal therapeutic agent for the ablation of lung cancer cells (A549). A single step bio facile fabrication of graphene nanosheets using Memecylon edule leaf extract intermediated reduction of Graphene Oxide (GO). This process does not include the utilization of any toxic or harmful reducing agents. The relative results of different characterizations of graphene oxide and Memecylon edule leaf extract RGO delivers a potential representation by excluding the groups containing oxygen from GO and consecutive stabilization of the developed RGO. The reduced GO functionalization with the oxidized polyphenols results in their stability by avoiding the aggregation. The poly phenol anchored Reduced Graphene Oxide (RGO) exhibited exceptional near-infrared (NIR) irradiation of the lung cancer cells directed in vitro to deliver cytotoxicity. In an area of restricted success in the treatment of cancer, the results of our translation can provide a path for designing targeted PTT agents and also responds to stimulus environment for the safe ablation of the devastating disease.


Assuntos
Grafite/química , Raios Infravermelhos , Nanoestruturas/química , Polifenóis/química , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Cães , Química Verde , Humanos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/terapia , Células Madin Darby de Rim Canino , Magnoliopsida/química , Magnoliopsida/metabolismo , Nanoestruturas/uso terapêutico , Nanoestruturas/toxicidade , Fototerapia/métodos , Extratos Vegetais/química , Folhas de Planta/química , Folhas de Planta/metabolismo
17.
Lasers Med Sci ; 35(5): 1205-1212, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32030556

RESUMO

The aim of this study was to assess the effects of IL-6 and IL-8 cytokines on human gingival fibroblasts (HGF) cultured in a 3-D model and the possible photobiomodulation (PBM) of such effects by low-level laser therapy. In complete culture medium (DMEM), HGF from a healthy patient were seeded in a type I collagen matrix inserted into 24-well plates. After 5 days of incubation, the cytokines were added or not to serum-free DMEM, which was applied to the cell-enriched matrices. Then, PBM was performed: three consecutive irradiations using LaserTable diode device (780 nm, 0.025 W) at 0.5 J/cm2 were delivered or not to the cells. Twenty-four hours after the last irradiation, cell viability and morphology, gene expression, and synthesis of inflammatory cytokines and growth factors were assessed. The histological evaluation demonstrated that, for all groups, matrices presented homogeneous distribution of cells with elongated morphology. However, numerous cytokine-exposed cells were rounded. IL-6 and IL-8 decreased cell viability, synthesis of VEGF, and gene expression of collagen type I. PBM enhanced cell density in the matrices and stimulated VEGF expression, even after IL-6 challenge. Reduced TNF-α synthesis occurred in those cells subjected to PBM. In conclusion, PBM can penetrate collagen matrix and stimulate HGF, highlighting the relevance of this research model for further phototherapy studies and in vitro biomodulation of the healing process.


Assuntos
Técnicas de Cultura de Células/métodos , Citocinas/metabolismo , Fibroblastos/patologia , Fibroblastos/efeitos da radiação , Gengiva/patologia , Inflamação/patologia , Terapia com Luz de Baixa Intensidade , Modelos Biológicos , Sobrevivência Celular/efeitos da radiação , Colágeno Tipo I/metabolismo , Regulação da Expressão Gênica/efeitos da radiação , Humanos , Interleucina-1beta/biossíntese , Fator de Necrose Tumoral alfa/biossíntese , Fator A de Crescimento do Endotélio Vascular/biossíntese , Cicatrização/efeitos da radiação
18.
Biochim Biophys Acta Mol Cell Res ; 1867(6): 118678, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32061892

RESUMO

The endothelium contributes to the pathophysiology of adverse effects caused by conventional (genotoxic) anticancer therapeutics (cAT). The relevance of structurally different types of cAT-induced DNA lesions for eliciting selected endothelial stress responses is largely unknown. Here, we analyzed the cAT-induced formation of DNA double-strand breaks (DSB), transcription blockage and DNA damage response (DDR) in time kinetic analyses employing a monolayer of primary human endothelial cells (HUVEC). We observed that the degree of cAT-induced transcription blockage, the number of DSB and activation of DDR-related factors diverge. For instance, ionizing radiation caused the formation of numerous DSB and triggerd a substantial activation of ATM/Chk2 signaling, which however were not accompanied by a significant transcription inhibition. By contrast, the DNA cross-linking cAT cisplatin triggered a rapid and substantial blockage of transcription, which yet was not reflected by an appreciable number of DSB or increased levels of pATM/pChk2. In general, cAT-stimulated ATM-dependent phosphorylation of Kap1 (Ser824) and p53 (Ser15) reflected best cAT-induced transcription blockage. In conclusion, cAT-induced formation of DSB and profound activation of prototypical DDR factors is independent of the inhibition of RNA polymerase II-regulated transcription in an endothelial monolayer. We suggest that DSB formed directly or indirectly following cAT-treatment do not act as comprehensive triggers of superior signaling pathways shutting-down transcription while, at the same time, causing an appreciable stimulation of the DDR. Rather, it appears that distinct cAT-induced DNA lesions elicit diverging signaling pathways, which separately control transcription vs. DDR activity in the endothelium.


Assuntos
Antineoplásicos/farmacologia , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Quinase do Ponto de Checagem 2/metabolismo , Cisplatino/farmacologia , Proteína 28 com Motivo Tripartido/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Quebras de DNA de Cadeia Dupla , Células Endoteliais da Veia Umbilical Humana , Humanos , Fosforilação/efeitos dos fármacos , Fosforilação/efeitos da radiação , Cultura Primária de Células , Radiação Ionizante , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/efeitos da radiação , Ativação Transcricional/efeitos dos fármacos , Ativação Transcricional/efeitos da radiação
19.
Lasers Med Sci ; 35(3): 741-749, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32095920

RESUMO

This in vitro study evaluated the role of photobiomodulation therapy (PBMT) on viability and migration of human dental pulp stem cells (hDPSCs) and its association to epigenetic mechanisms such as histone acetylation. The hDPSCs were characterized and assigned into control and PBMT groups. For the PBMT, five laser irradiations at 6-h intervals were performed using a continuous-wave InGaAlP diode laser. Viability (MTT), migration (scratch), and histone acetylation H3 (H3K9ac immunofluorescence) were evaluated immediately after the last irradiation. PBMT significantly increased the viability (P = 0.004). Also, PBMT group showed significantly increased migration of cells in the wound compared to the control in 6 h (P = 0.002), 12 h (P = 0.014) and 18 h (P = 0.083) being faster than the control, which only finished the process at 24 h. PBMT induced epigenetic modifications in hDPSC due to increased histone acetylation (P = 0.001). PBMT increased viability and migration of hDPSCs, which are related with the upregulation of histone acetylation and could be considered a promising adjuvant therapy for regenerative endodontic treatment.


Assuntos
Movimento Celular/efeitos da radiação , Polpa Dentária/citologia , Histonas/metabolismo , Terapia com Luz de Baixa Intensidade , Células-Tronco/citologia , Células-Tronco/efeitos da radiação , Regulação para Cima/efeitos da radiação , Acetilação/efeitos da radiação , Sobrevivência Celular/efeitos da radiação , Humanos , Células-Tronco/metabolismo
20.
Lasers Med Sci ; 35(7): 1509-1518, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32065300

RESUMO

In spinal cord injury (SCI), inflammation is a major mediator of damage and loss of function and is regulated primarily by the bone marrow-derived macrophages (BMDMs). Photobiomodulation (PBM) or low-level light stimulation is known to have anti-inflammatory effects and has previously been used in the treatment of SCI, although its precise cellular mechanisms remain unclear. In the present study, the effect of PBM at 810 nm on classically activated BMDMs was evaluated to investigate the mechanisms underlying its anti-inflammatory effects. BMDMs were cultured and irradiated (810 nm, 2 mW/cm2) following stimulation with lipopolysaccharide and interferon-γ. CCK-8 assay, 2',7'-dichlorofluorescein diacetate assay, and ELISA and western blot analysis were performed to measure cell viability, reactive oxygen species production, and inflammatory marker production, respectively. PBM irradiation of classically activated macrophages significantly increased the cell viability and inhibited reactive oxygen species generation. PBM suppressed the expression of a marker of classically activated macrophages, inducible nitric oxide synthase; decreased the mRNA expression and secretion of pro-inflammatory cytokines, tumor necrosis factor alpha, and interleukin-1 beta; and increased the secretion of monocyte chemotactic protein 1. Exposure to PBM likewise significantly reduced the expression and phosphorylation of NF-κB p65 in classically activated BMDMs. Taken together, these results suggest that PBM can successfully modulate inflammation and polarization in classically activated BMDMs. The present study provides a theoretical basis to support wider clinical application of PBM in the treatment of SCI.


Assuntos
Polaridade Celular , Inflamação/radioterapia , Macrófagos/patologia , Animais , Polaridade Celular/efeitos da radiação , Sobrevivência Celular/efeitos da radiação , Quimiocinas/genética , Quimiocinas/metabolismo , Regulação da Expressão Gênica/efeitos da radiação , Ativação de Macrófagos/efeitos da radiação , Macrófagos/efeitos da radiação , Camundongos Endogâmicos BALB C , Fosforilação/efeitos da radiação , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Fator de Transcrição RelA/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA