Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 96
Filtrar
1.
ACS Appl Mater Interfaces ; 16(30): 39528-39538, 2024 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-39015032

RESUMEN

Structural imperfections can cause both beneficial and detrimental consequences on the excitonic characteristics of transition metal dichalcogenides (TMDs). Regarding valley selection, structural defects typically promote valley depolarization in monolayer TMDs, but defect healing via an additional growth process can restore valley polarization in vertical heterobilayers (VHs). In this study, we analyzed the valley polarization of center-nucleated and edge-nucleated VHs (WS2/MoS2) grown using a controlled growth process and discovered that defect-related photoluminescence (PL) is strongly suppressed in the center-nucleated VHs due to defect healing. Additionally, we demonstrated that the valley polarization of lower-lying intralayer excitons is more sensitive to the defect density of the sample than to higher-lying intralayer excitons. Despite defect healing in the center-nucleated VHs, the temperature-dependent PL study indicated that valley depolarization of the lower-lying intralayer excitons becomes significant below 100 K because of stronger hybridization of defect states. Also, we conducted a comprehensive study on the excitation intensity dependence to investigate the electron-doping-induced Auger recombination mechanism, which also contributes to valley depolarization of intralayer excitons via regeneration of intervalley trions. Our findings provide valuable insight into the development of VH-based valleytronic devices.

2.
Biomed Rep ; 20(1): 4, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38124767

RESUMEN

Nutmeg is the seed derived from Myristica fragrans. Nutmeg seeds contain alkylbenzene derivatives such as myristicin, which are toxic to the human organism, and lignan compounds such as nectandrin B, which possess anti-aging and anti-diabetic properties. However, the anti-adipogenic, prolipolytic and anti-inflammatory effects of lignan-enriched nutmeg extract (LNX) on preadipocytes remain unclear. In the present study, the effects of LNX on lipid accumulation, glycerol release and inflammatory cyclooxygenase-2 (COX-2) expression in differentiated 3T3-L1 preadipocytes were investigated. Oil red O staining demonstrated that treatment with LNX resulted in a concentration-dependent reduction in lipid accumulation in differentiating 3T3-L1 preadipocytes without affecting cell growth. Mechanistically, LNX treatment at 6 µg/ml led to a reduction in phosphorylation levels of signal transducer and activator of transcription 3 (STAT3), whereas it did not influence the peroxisome proliferator-activated receptor gamma (PPAR-γ) and CCAAT enhancer binding protein alpha (C/EBP-α) expression levels during 3T3-L1 preadipocyte differentiation. In addition, LNX treatment at 6 µg/ml led to a decrease in fatty acid synthase (FAS) expression levels on day (D) 2, but not D5 and D8, during preadipocyte differentiation. Treatment with LNX at 6 µg/ml did not affect the expression levels of perilipin A during preadipocyte differentiation. In differentiated 3T3-L1 adipocytes, LNX treatment at 6 µg/ml did not stimulate glycerol release and hormone-sensitive lipase phosphorylation, which are known lipolysis hallmarks. Furthermore, LNX treatment at the doses tested had no effect on tumor necrosis factor alpha-induced COX-2 expression in 3T3-L1 preadipocytes. Collectively, these results demonstrated that LNX has an anti-adipogenic effect on differentiating 3T3-L1 preadipocytes, which is mediated by the downregulation of STAT3 phosphorylation and FAS expression.

3.
ACS Nano ; 17(3): 2629-2638, 2023 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-36688595

RESUMEN

Vertical type II van der Waals heterobilayers of transition metal dichalcogenides (TMDs) have attracted wide attention due to their distinctive features mostly arising from the emergence of intriguing electronic structures that include moiré-related phenomena. Owing to strong spin-orbit coupling under a noncentrosymmetric environment, TMD heterobilayers host nonequivalent +K and -K valleys of contrasting Berry curvatures, which can be optically controlled by the helicity of optical excitation. The corresponding valley selection rules are well established by not only intralayer excitons but also interlayer excitons. Quite intriguingly, here, we experimentally demonstrate that unusual valley switching can be achieved using the lowest-lying intralayer excitons in H-type heterobilayer WS2/MoS2 prepared by one-step growth. This TMD combination provides an ideal case for interlayer coupling with an almost perfect lattice match, thereby also in the momentum space between +K and -K valleys in the H-type heterostructure. The underlying valley-switching mechanism can be understood by bright-to-dark conversion of initially created electrons in the valley of WS2, followed by interlayer charge transfer to the opposite valley in MoS2. Our suggested model is also confirmed by the absence of valley switching when the lowest-lying excitons in MoS2 are directly generated in the heterobilayer. In contrast to the H-type case, we show that no valley switching is observed from R-type heterobilayers prepared by the same method, where interlayer charge transfer does not occur between the opposite valleys. We compare the case with the series of valley polarization data from other heterobilayer combinations obtained under different excitation energies and temperatures. Our valley switching mechanism can be utilized for valley manipulation by controlling the excitation photon energy together with the photon helicity in valleytronic devices derived from H-type TMD heterobilayers.

4.
ACS Appl Mater Interfaces ; 13(48): 57588-57596, 2021 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-34797625

RESUMEN

Noncentrosymmetric transition-metal dichalcogenides, particularly their 3R polymorphs, provide a robust setting for valleytronics. Here, we report on the selective growth of monolayers and bilayers of MoS2, which were acquired from two closely but differently oriented substrates in a chemical vapor deposition reactor. It turns out that as-grown bilayers are predominantly 3R-type, not more common 2H-type, as verified by microscopic and spectroscopic characterization. As expected, the 3R bilayer showed a significantly higher valley polarization compared with the centrosymmetric 2H bilayer, which undergoes efficient interlayer scattering across contrasting valleys because of their vertical alignment of the K and K' points in momentum space. Interestingly, the 3R bilayer showed even higher valley polarization compared with the monolayer counterpart. Moreover, the 3R bilayer reasonably maintained its valley efficiency over a very wide range of excitation power density from ∼0.16 kW/cm2 to ∼0.16 MW/cm2 at both low and room temperatures. These observations are rather surprising because valley dephasing could be more efficient in the bilayer via both interlayer and intralayer scatterings, whereas only intralayer scattering is allowed in the monolayer. The improved valley polarization of the 3R bilayer can be attributed to its indirect-gap nature, where valley-polarized excitons can relax into the valley-insensitive band edge, which otherwise scatter into the contrasting valley to effectively cancel out the initial valley polarization. Our results provide a facile route for the growth of 3R-MoS2 bilayers that could be utilized as a platform for advancing valleytronics.

5.
Nat Commun ; 12(1): 6453, 2021 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-34753923

RESUMEN

Anisotropic triangular antiferromagnets can host two primary spin excitations, namely, spinons and triplons. Here, we utilize polarization-resolved Raman spectroscopy to assess the statistics and dynamics of spinons in Ca3ReO5Cl2. We observe a magnetic Raman continuum consisting of one- and two-pair spinon-antispinon excitations as well as triplon excitations. The twofold rotational symmetry of the spinon and triplon excitations are distinct from magnons. The strong thermal evolution of spinon scattering is compatible with the bosonic spinon scenario. The quasilinear spinon hardening with decreasing temperature is envisaged as the ordering of one-dimensional topological defects. This discovery will enable a fundamental understanding of novel phenomena induced by lowering spatial dimensionality in quantum spin systems.

6.
Sci Rep ; 11(1): 21202, 2021 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-34707186

RESUMEN

Gallium Telluride (GaTe), a layered material with monoclinic crystal structure, has recently attracted a lot of attention due to its unique physical properties and potential applications for angle-resolved photonics and electronics, where optical anisotropies are important. Despite a few reports on the in-plane anisotropies of GaTe, a comprehensive understanding of them remained unsatisfactory to date. In this work, we investigated thickness-dependent in-plane anisotropies of the 13 Raman-active modes and one Raman-inactive mode of GaTe by using angle-resolved polarized Raman spectroscopy, under both parallel and perpendicular polarization configurations in the spectral range from 20 to 300 cm-1. Raman modes of GaTe revealed distinctly different thickness-dependent anisotropies in parallel polarization configuration while nearly unchanged for the perpendicular configuration. Especially, three Ag modes at 40.2 ([Formula: see text]), 152.5 ([Formula: see text]), and 283.8 ([Formula: see text]) cm-1 exhibited an evident variation in anisotropic behavior as decreasing thickness down to 9 nm. The observed anisotropies were thoroughly explained by adopting the calculated interference effect and the semiclassical complex Raman tensor analysis.

7.
Sci Rep ; 11(1): 7843, 2021 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-33846520

RESUMEN

Van der Waals (vdW) heterostructures, consisting of a variety of low-dimensional materials, have great potential use in the design of a wide range of functional devices thanks to their atomically thin body and strong electrostatic tunability. Here, we demonstrate multi-functional indium selenide (InSe)/black phosphorous (BP) heterostructures encapsulated by hexagonal boron nitride. At a positive drain bias (VD), applied on the BP while the InSe is grounded, our heterostructures show an intermediate gate voltage (VBG) regime where the current hardly changes, working as a ternary transistor. By contrast, at a negative VD, the device shows strong negative differential transconductance characteristics; the peak current increases up to ~5 µA and the peak-to-valley current ratio reaches 1600 at VD = -2 V. Four-terminal measurements were performed on each layer, allowing us to separate the contributions of contact resistances and channel resistance. Moreover, multiple devices with different device structures and contacts were investigated, providing insight into the operation principle and performance optimization. We systematically investigated the influence of contact resistances, heterojunction resistance, channel resistance, and the thickness of BP on the detailed operational characteristics at different VD and VBG regimes.

8.
Phys Chem Chem Phys ; 22(14): 7597-7605, 2020 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-32226986

RESUMEN

The long stagnation of the photo-conversion efficiency of kesterites below 13% is a source of frustration in the scientific community. In this study, we investigated the effects of sodium on the passivation of grain boundaries and defects in Cu2ZnSnSe4 (CZTSe) grown on a soda-lime glass (SLG) and borosilicate (BS) glass. Because BS glass does not inherently contain sodium, we placed a thin layer of NaF between CZTSe and Mo. The composition of the samples is Cu-poor and Zn-rich. The distribution of sodium and its contributions to phase formation and defects were examined by cross-sectional energy-dispersive X-ray profiling, Raman scattering spectroscopy and imaging, surface potential and photoluminescence. From the experimental results, it can be strongly claimed that sodium ions segregate predominantly near the grain boundaries and reduce CuZn-related defects. These local surface imaging analyses provided the exact locations of the secondary phases. In particular, the photo-assisted scanning probe method enabled us to observe the changes in the optoelectrical properties of the thin films and the carrier behavior within the materials. Further studies with distinct alkali ions and optimal processing conditions will pave a way to improve the performance of kesterite solar cells.

9.
J Ginseng Res ; 44(1): 50-57, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32148389

RESUMEN

BACKGROUND: The cellular senescence of primary cultured cells is an irreversible process characterized by growth arrest. Restoration of senescence by ginsenosides has not been explored so far. Rg3(S) treatment markedly decreased senescence-associated ß-galactosidase activity and intracellular reactive oxygen species levels in senescent human dermal fibroblasts (HDFs). However, the underlying mechanism of this effect of Rg3(S) on the senescent HDFs remains unknown. METHODS: We performed a label-free quantitative proteomics to identify the altered proteins in Rg3(S)-treated senescent HDFs. Upregulated proteins induced by Rg3(S) were validated by real-time polymerase chain reaction and immunoblot analyses. RESULTS: Finally, 157 human proteins were identified, and variable peroxiredoxin (PRDX) isotypes were highly implicated by network analyses. Among them, the mitochondrial PRDX3 was transcriptionally and translationally increased in response to Rg3(S) treatment in senescent HDFs in a time-dependent manner. CONCLUSION: Our proteomic approach provides insights into the partial reversing effect of Rg3 on senescent HDFs through induction of antioxidant enzymes, particularly PRDX3.

10.
ACS Appl Mater Interfaces ; 12(2): 2490-2496, 2020 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-31840505

RESUMEN

Steam generation by eco-friendly solar energy has immense potential in terms of low-cost power generation, desalination, sanitization, and wastewater treatment. Herein, highly efficient steam generation in a bilayer solar steam generator (BSSG) is demonstrated, which is comprised of a large-area SnSe-SnSe2 layer deposited on a glassy carbon foam (CF). Both CF and SnSe-SnSe2 possess high photothermal conversion capabilities and low thermal conductivities. The combined bilayer system cumulatively converts input solar light into heat through phonon-assisted transitions in the indirect band gap SnSe-SnSe2 layer, together with trapping of sunlight via multiple scattering due to the porous morphology of the CF. This synergistic effect leads to efficient broadband solar absorption. Moreover, the low out-of-plane thermal conductivities of SnSe-SnSe2 and CF confine the generated heat at the evaporation surface, resulting in a significant reduction of heat losses. Additionally, the hydrophilic nature of the acid-treated CF offers effective water transport via capillary action, required for efficient solar steam generation in a floating form. A high evaporation rate (1.28 kg m-2 h-1) and efficiency (84.1%) are acquired under 1 sun irradiation. The BSSG system shows high recyclability, stability, and durability under repeated steam-generation cycles, which renders its practical device applications possible.

11.
Small ; 15(38): e1901793, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31379110

RESUMEN

Band-like transport behavior of H-doped transition metal dichalcogenide (TMD) channels in field effect transistors (FET) is studied by conducting low-temperature electrical measurements, where MoTe2 , WSe2 , and MoS2 are chosen for channels. Doped with H atoms through atomic layer deposition, those channels show strong n-type conduction and their mobility increases without losing on-state current as the measurement temperature decreases. In contrast, the mobility of unintentionally (naturally) doped TMD FETs always drops at low temperatures whether they are p- or n-type. Density functional theory calculations show that H-doped MoTe2 , WSe2 , and MoS2 have Fermi levels above conduction band edge. It is thus concluded that the charge transport behavior in H-doped TMD channels is metallic showing band-like transport rather than thermal hopping. These results indicate that H-doped TMD FETs are practically useful even at low-temperature ranges.

12.
Nanotechnology ; 30(38): 384001, 2019 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-31181554

RESUMEN

High quality gallium sulfide II (GaS) and gallium sulfide III ([Formula: see text]) thin films on [Formula: see text]/Si substrates were simultaneously grown by using physical vapor deposition with GaS powder as a single precursor. By controlling the substrate temperature, we can selectively grow either GaS or Ga2S3 thin films on SiO2/Si substrates. Relatively high and low substrate temperature conditions resulted in Ga2S3 and GaS thin films, respectively. The synthesized thin films were characterized by x-ray diffraction, Raman spectroscopy, field emission scanning electron microscopy, atomic force microscopy, and x-ray photoelectron spectroscopy analyses.

13.
Sci Rep ; 6: 39334, 2016 12 23.
Artículo en Inglés | MEDLINE | ID: mdl-28008951

RESUMEN

Insulin-like growth factor-binding protein 5 (IGFBP-5) plays a role in cell growth, differentiation, and apoptosis. In this study, we found that IGFBP5 was markedly downregulated in ovarian cancer tissue. We investigated the functional significance of IGFBP-5 as a tumor suppressor. To determine functional regions of IGFBP-5, truncation mutants were prepared and were studied the effect on tumor growth. Expression of C-terminal region of IGFBP-5 significantly decreased tumor growth in an ovarian cancer xenograft. A peptide derived from the C-terminus of IGFBP-5 (BP5-C) was synthesized to evaluate the minimal amino acid motif that retained anti-tumorigenic activity and its effect on angiogenesis was studied. BP5-C peptide decreased the expression of VEGF-A and MMP-9, phosphorylation of Akt and ERK, and NF-kB activity, and inhibited angiogenesis in in vitro and ex vivo systems. Furthermore, BP5-C peptide significantly decreased tumor weight and angiogenesis in both ovarian cancer orthotopic xenograft and patient-derived xenograft mice. These results suggest that the C-terminus of IGFBP-5 exerts anti-cancer activity by inhibiting angiogenesis via regulation of the Akt/ERK and NF-kB-VEGF/MMP-9 signaling pathway, and might be considered as a novel angiogenesis inhibitor for the treatment of ovarian cancer.


Asunto(s)
Proteína 5 de Unión a Factor de Crecimiento Similar a la Insulina/metabolismo , Neovascularización Patológica , Neoplasias Ováricas/patología , Animales , Análisis Mutacional de ADN , Modelos Animales de Enfermedad , Femenino , Xenoinjertos , Humanos , Proteína 5 de Unión a Factor de Crecimiento Similar a la Insulina/genética , Ratones , Trasplante de Neoplasias , Eliminación de Secuencia , Transducción de Señal
14.
Artículo en Inglés | MEDLINE | ID: mdl-25768551

RESUMEN

Recently large-scale cascading failures in complex systems have garnered substantial attention. Such extreme events have been treated as an integral part of self-organized criticality (SOC). Recent empirical work has suggested that some extreme events systematically deviate from the SOC paradigm, requiring a different theoretical framework. We shed additional theoretical light on this possibility by studying financial crisis. We build our model of financial crisis on the well-known forest fire model in scale-free networks. Our analysis shows a nontrivial scaling feature indicating supercritical behavior, which is independent of system size. Extreme events in the supercritical state result from bursting of a fat bubble, seeds of which are sown by a protracted period of a benign financial environment with few shocks. Our findings suggest that policymakers can control the magnitude of financial meltdowns by keeping the economy operating within reasonable duration of a benign environment.

15.
Chem Commun (Camb) ; 48(93): 11431-3, 2012 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-23086600

RESUMEN

New phenothiazine-based organic dyes with two anchoring groups at 3,7 positions and systematic alkyl chains on nitrogen were prepared. Their TiO(2)-Pt composites showed excellent photo-catalytic activities in visible light-induced water splitting. Interestingly, phenothiazine dyes with longer alkyl chains showed better stability in catalytic systems.

16.
Gynecol Obstet Invest ; 74(4): 313-9, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23075517

RESUMEN

AIM: To evaluate prognostic factors in Korean patients with endometrial cancer. METHODS: A retrospective analysis was conducted on 248 patients who were staged surgically at the Samsung Medical Center between 1995 and 2004. Survival data were analyzed using Kaplan-Meier estimates, and multivariate analysis was performed using the Cox regression method. RESULTS: The median age was 51 years (range 21-75), which was younger than in previous studies in Western patients, and the age of 50 years was the cutoff to predict survival. More than half (55.6%) were normal weight or underweight (BMI <25). Multivariate analysis revealed that age, Fédération Internationale de Gynécologie et d'Obstétrique (FIGO) stage, and histopathology were independent predictors of disease-free survival, and FIGO stage and p53 mutation were independent prognostic factors for disease-specific survival (DSS). The 5-year DSS for patients with stage I, II, III and IV disease was 95.6, 93.8, 69.8 and 50%, respectively. The 5-year DSS rate for patients with a p53 mutation was 84.4%, compared with 97.1% for patients without. CONCLUSIONS: Korean patients with endometrial cancer were younger and had a lower BMI than previously reported. Furthermore, age greater than 50 years was predictive of a poor outcome. Age, FIGO stage, histopathology and a p53 mutation were independent prognostic factors for survival.


Asunto(s)
Carcinoma Endometrioide/genética , Carcinoma Endometrioide/secundario , Neoplasias Endometriales/genética , Neoplasias Endometriales/patología , Proteína p53 Supresora de Tumor/genética , Adulto , Anciano , Antígeno Ca-125/sangre , Carcinoma Endometrioide/cirugía , Supervivencia sin Enfermedad , Neoplasias Endometriales/cirugía , Femenino , Estudios de Seguimiento , Humanos , Estimación de Kaplan-Meier , Metástasis Linfática , Proteínas de la Membrana/sangre , Persona de Mediana Edad , Análisis Multivariante , Mutación , Invasividad Neoplásica , Estadificación de Neoplasias , Modelos de Riesgos Proporcionales , Receptores de Estrógenos/metabolismo , Receptores de Progesterona/metabolismo , República de Corea , Estudios Retrospectivos , Tasa de Supervivencia , Factores de Tiempo , Adulto Joven
17.
PLoS One ; 7(8): e42006, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22870275

RESUMEN

The p53 tumor suppressor function can be compromised in many tumors by the cellular antagonist HDM2 and human papillomavirus oncogene E6 that induce p53 degradation. Restoration of p53 activity has strong therapeutic potential. Here, we identified TSC-22 as a novel p53-interacting protein and show its novel function as a positive regulator of p53. We found that TSC-22 level was significantly down-regulated in cervical cancer tissues. Moreover, over-expression of TSC-22 was sufficient to inhibit cell proliferation, promote cellular apoptosis in cervical cancer cells and suppress growth of xenograft tumors in mice. Expression of also TSC-22 enhanced the protein level of p53 by protecting it from poly-ubiquitination. When bound to the motif between amino acids 100 and 200 of p53, TSC-22 inhibited the HDM2- and E6-mediated p53 poly-ubiquitination and degradation. Consequently, ectopic over-expression of TSC-22 activated the function of p53, followed by increased expression of p21(Waf1/Cip1) and PUMA in human cervical cancer cell lines. Interestingly, TSC-22 did not affect the interaction between p53 and HDM2. Knock-down of TSC-22 by small interfering RNA clearly enhanced the poly-ubiquitination of p53, leading to the degradation of p53. These results suggest that TSC-22 acts as a tumor suppressor by safeguarding p53 from poly-ubiquitination mediated-degradation.


Asunto(s)
Complejo de la Endopetidasa Proteasomal/metabolismo , Proteolisis , Proteínas Represoras/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Ubiquitinación , Neoplasias del Cuello Uterino/metabolismo , Animales , Apoptosis/genética , Proliferación Celular , Regulación hacia Abajo/genética , Femenino , Regulación Neoplásica de la Expresión Génica/genética , Técnicas de Silenciamiento del Gen , Células HeLa , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Complejo de la Endopetidasa Proteasomal/genética , Proteínas Proto-Oncogénicas c-mdm2/genética , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , ARN Interferente Pequeño , Proteínas Represoras/genética , Proteína p53 Supresora de Tumor/genética , Neoplasias del Cuello Uterino/genética , Neoplasias del Cuello Uterino/patología
18.
Cancer Res Treat ; 44(2): 142-5, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22802753

RESUMEN

Clinical observation of skin metastasis in ovarian cancer cases is relatively uncommon. And distant metastatic skin lesions including the extremities are much rarer still as most metastatic skin lesions are located in the skin in the abdominal wall adjacent to where the primary ovarian tumors exist. We report the case of a 60-year-old woman who presented skin lesions on both lower extremities as a consequence of the metastasis of serous papillary adenocarcinoma of the ovary. She presented with erythematous and painful cutaneous nodules on both upper legs and in the inguinal area 42 months after initial diagnosis of ovarian cancer. Skin biopsy revealed metastasis of adenocarcinoma in the dermis. She was treated with surgical excision and systemic chemotherapy. Literature review has suggested that a combined modality approach including surgical excision and chemotherapy may be useful in the management of skin metastases due to ovarian cancer.

19.
PLoS One ; 7(5): e35399, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22623951

RESUMEN

Thymosin ß(10) (Tß(10)) regulates actin dynamics as a cytoplasm G-actin sequestering protein. Previously, we have shown that Tß(10) diminishes tumor growth, angiogenesis, and proliferation by disrupting actin and by inhibiting Ras. However, little is known about its mechanism of action and biological function. In the present study, we establish a new gene therapy model using a genetically modified adenovirus, referred to as Ad.TERT.Tß(10), that can overexpress the Tß(10) gene in cancer cells. This was accomplished by replacing the native Tß(10) gene promoter with the human TERT promoter in Ad.TERT.Tß(10). We investigated the cancer suppression activity of Tß(10) and found that Ad.TERT.Tß(10) strikingly induced cancer-specific expression of Tß(10) as well as apoptosis in a co-culture model of human primary ovarian cancer cells and normal fibroblasts. Additionally, Ad.TERT.Tß(10) decreased mitochondrial membrane potential and increased reactive oxygen species (ROS) production. These effects were amplified by co-treatment with anticancer drugs, such as paclitaxel and cisplatin. These findings indicate that the rise in ROS production due to actin disruption by Tß(10) overexpression increases apoptosis of human ovarian cancer cells. Indeed, the cancer-specific overexpression of Tß(10) by Ad.TERT.Tß(10) could be a valuable anti-cancer therapeutic for the treatment of ovarian cancer without toxicity to normal cells.


Asunto(s)
Apoptosis/fisiología , Regulación Neoplásica de la Expresión Génica/genética , Terapia Genética/métodos , Neoplasias Ováricas/terapia , Especies Reactivas de Oxígeno/metabolismo , Timosina/metabolismo , Actinas/metabolismo , Adenoviridae , Anexina A5 , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Cisplatino , Cartilla de ADN/genética , Femenino , Citometría de Flujo , Fluoresceína-5-Isotiocianato , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Técnicas de Transferencia de Gen , Humanos , Inmunohistoquímica , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Invasividad Neoplásica/fisiopatología , Neoplasias Ováricas/fisiopatología , Paclitaxel , Regiones Promotoras Genéticas/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Telomerasa/genética , Timosina/genética , Timosina/farmacología
20.
Anticancer Res ; 32(4): 1555-61, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22493401

RESUMEN

AIM: This study was designed to investigate the prognostic value of the neutrophil:lymphocyte ratio (NLR) in cervical cancer. PATIENTS AND METHODS: Patients with clinically staged cervical carcinoma (IB to IVA) at Samsung Medical Center, Seoul, Korea, from 1996 to 2007 were retrospectively enrolled. RESULTS: We enrolled 1061 patients with cervical cancer. The median NLR was 1.9, with a range of 0.3-27.0. When the cohort was divided according to the median NLR, poorer survival outcomes were observed in the group with higher NLR (≥1.9) than in the lower NLR group (<1.9). Patients of the higher NLR group (≥1.9) were younger in age and had more advanced staged disease when compared with those of the lower NLR group (<1.9). In multivariable analysis, higher pretreatment NLR was identified as being an independent poor prognostic factor for survival. CONCLUSION: Pretreatment NLR may be a cost-effective biomarker to stratify risk of recurrence and death in patients with cervical cancer.


Asunto(s)
Recuento de Linfocitos , Neutrófilos , Neoplasias del Cuello Uterino/patología , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Persona de Mediana Edad , Pronóstico , Neoplasias del Cuello Uterino/sangre
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...