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1.
Macromol Rapid Commun ; 44(5): e2200766, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36377472

RESUMEN

The enhancement in dielectric properties and self-healing ability for dielectric materials has been a challenging subject these years. Herein, a series of self-healed dielectric elastomers by combining the ferric ions and carboxyl-containing poly(sulfone siloxane)s is reported. Experimental results indicate the excellent dielectric properties of obtained elastomers, as the dielectric constant up to 12.8. SEM micrographs exhibit that carboxyl groups and ferric ions can aggregate together to generate clusters, which further result in interfacial polarization. Besides, high polarity dipole units including sulfonyl units and carboxyl groups contribute to dipole polarization. The overlay of the two mentioned polarization eventually results in the high dielectric property. The dielectric constant obviously increases with the contents of carboxyl groups and ferric ions. Moreover, the samples are feasible for recycling and reprocessing with high self-healing efficiency, owing to the reversibility of the coordination bond. A self-healing efficiency of 92.1% in tensile strength of the obtained samples can be reached after 2 h treatment at 60 °C. And the elastomers can also conveniently recover most mechanical properties after solution treatment. This work may offer a promising method for preparing dielectric elastomers with high dielectric properties and self-healing ability.


Asunto(s)
Elastómeros , Siloxanos , Elastómeros/química , Siloxanos/química , Resistencia a la Tracción , Iones
2.
Macromol Rapid Commun ; 42(5): e2000606, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33270321

RESUMEN

The preparation of a series of luminescent perovskite-silicone elastomer (PSE) composites by embedding inorganic lead halide perovskite nanocrystals (CsPbBr3 NCs) into networks constructed by trimethylolpropane tris(2-mercaptoacetate) and sulfone-containing silicone copolymers with vinyl side groups (PSMVS) is reported herein. The networks are obtained by an environmentally friendly thiol-ene cross-linking reaction under 30 W household LED light. The conducted analysis shows that the prepared PSEs display strong green fluorescence due to encapsulation of CsPbBr3 NCs, which constitute a luminescent center in sulfone-containing silicone networks. Using PSMVS as basic polymers instead of commercial polysiloxanes endows PSEs with enhanced mechanical strength and excellent luminescent stability at high temperatures. The PSEs show robust tensile stress and >650% elongation. Additionally, the construction of colorful ultraviolet light-emitting diodes (UV-LEDs) by an in situ cross-linking process is described.


Asunto(s)
Elastómeros de Silicona , Compuestos de Sulfhidrilo , Compuestos de Calcio , Luminiscencia , Óxidos , Titanio
3.
Acta Obstet Gynecol Scand ; 100(2): 302-313, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-32981061

RESUMEN

INTRODUCTION: Biological rhythms, the innate cycle of changes in the body's physiological functions, are circadian if they have a 24-hour period. It is known that sleep is a key feature of human circadian rhythm but the relation between sleep and female fertility is largely unknown. This paucity of research is surprising given that circadian rhythms are paramount to human physiology and sleep is related to major female reproductive events. This study was designed to investigate whether there is a difference between the sleep and activity parameters of women with poor reproductive outcome compared with healthy, fertile parous women (comparator group) using subjective (questionnaires) and objective (actigraphy and light exposure) measures. MATERIAL AND METHODS: A prospective cohort study in a tertiary in vitro fertilization referral center in the UK; composed of three study groups: women diagnosed with recurrent implantation failure, women with recurrent miscarriage (RM) and a comparison group (fertile women without endometrial pathology). Comparison women were selected gynecology patients without endometrial disease (ie perineal complaints or altruistic egg donors). Primary outcome was differences in objective length of sleep in each of the participant groups using actigraphy. Secondary outcomes were subjective sleep quality and quantity, using participant questionnaires, light exposure, and the feasibility of machine learning in activity-pattern interpretation. RESULTS: Women with recurrent implantation failure slept daily on average for 7 hours 35 minutes (± 57 min), 53 minutes less than the comparison group (P = .03), although quality of their objective sleep, and quantity of their subjective sleep, were not significantly different. Women with recurrent miscarriage slept less that the comparison women (36 minutes less/night) but more than women with recurrent implantation failure (17 minutes more/night). No difference in light exposure was found between recurrent miscarriage and the recurrent implantation failure and comparison groups. CONCLUSIONS: This study demonstrates an objective observation of sleep time reduction in women with subfertility, although it is not yet clear if this association is casual. Given our increased understanding of the internal body clock and circadian rhythm on fertility, our observation warrants further investigation.


Asunto(s)
Aborto Habitual/epidemiología , Infertilidad Femenina/epidemiología , Trastornos del Sueño-Vigilia/epidemiología , Adulto , Estudios de Cohortes , Femenino , Fertilización In Vitro , Humanos , Luz , Embarazo
4.
Eur Radiol ; 26(1): 64-71, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25925361

RESUMEN

OBJECTIVES: To show the ability of using the amide proton transfer-weighted (APTW) MRI signals as imaging biomarkers to differentiate primary central nervous system lymphomas (PCNSLs) from high-grade gliomas (HGGs). METHODS: Eleven patients with lymphomas and 21 patients with HGGs were examined. Magnetization-transfer (MT) spectra over an offset range of ± 6 ppm and the conventional MT ratio (MTR) at 15.6 ppm were acquired. The APTW signals, total chemical-exchange-saturation-transfer signal (integral between 0 and 5 ppm, CEST total), and MTR signal were obtained and compared between PCNSLs and HGGs. The diagnostic performance was assessed with the receiver operating characteristic (ROC) curve analysis. RESULTS: The PCNSLs usually showed more homogeneous APTW hyperintensity (spatially compared to normal brain tissue) than the HGGs. The APTW max, APTW max-min and CEST total signal intensities were significantly lower (P < 0.05, 0.001 and 0.05, respectively), while the APTW min and MTR were significantly higher (both P < 0.01) in PCNSL lesions than in HGG lesions. The APTW values in peritumoral oedema were significantly lower for PCNSLs than for HGGs (P < 0.01). APTW max-min had the highest area under the ROC curve (0.963) and accuracy (94.1 %) in differentiating PCNSLs from HGGs. CONCLUSIONS: The protein-based APTW signal would be a valuable MRI biomarker by which to identify PCNSLs and HGGs presurgically. KEY POINTS: PCNSLs overall showed more homogeneous APTW hyperintensity than HGGs. Maximum APTW signals were lower in PCNSL lesions than in HGG lesions. MTR signals were higher in PCNSLs than in HGGs. APTW heterogeneity had the highest accuracy in differentiating PCNSLs from HGGs.


Asunto(s)
Neoplasias Encefálicas/patología , Glioma/patología , Linfoma no Hodgkin/patología , Adulto , Anciano , Anciano de 80 o más Años , Amidas , Encéfalo/patología , Diagnóstico Diferencial , Femenino , Humanos , Linfoma/patología , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Neuroimagen/métodos , Protones , Curva ROC , Estudios Retrospectivos
5.
Mol Carcinog ; 53(10): 841-6, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23625632

RESUMEN

Lung adenocarcinoma (AdC) and lung squamous cell carcinoma (SCC) are the most common non-small cell lung cancer (NSCLC) subtypes, however, most genetic mouse models of lung cancer produce predominantly, if not exclusively, AdC. Whether this is secondary to targeting mutations to the distal airway cells or to the use of activating Kras mutations that drive AdC formation is unknown. We previously showed that targeting Kras(G12D) activation and transforming growth factor ß receptor type II (TGFßRII) deletion to airway basal cells via a keratin promoter induced formation of both lung AdC and SCC. In this study we assessed if targeting phosphatase and tensin homologue (PTEN) deletion to airway basal cells could initiate lung tumor formation or increase lung SCC formation. We found that PTEN deletion is capable of initiating both lung AdC and SCC formation when targeted to basal cells and although PTEN deletion is a weaker tumor initiator than Kras(G12D) with low tumor multiplicity and long latency, tumors initiated by PTEN deletion were larger and displayed more malignant conversion than Kras(G12D) initiated tumors. That PTEN deletion did not increase lung SCC formation compared to Kras(G12D) activation, suggests that the initiating genetic event does not dictate tumor histology when genetic alterations are targeted to a specific cell. These studies also confirm that basal cells of the conducting airway are capable of giving rise to multiple NSCLC tumor types.


Asunto(s)
Carcinoma de Células Escamosas/metabolismo , Neoplasias Pulmonares/metabolismo , Neoplasias Basocelulares/metabolismo , Fosfohidrolasa PTEN/genética , Animales , Carcinoma de Células Escamosas/genética , Eliminación de Gen , Humanos , Neoplasias Pulmonares/genética , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Mutación Missense , Neoplasias Basocelulares/genética , Fosfohidrolasa PTEN/deficiencia , Proteínas Proto-Oncogénicas p21(ras)/metabolismo
6.
Int Immunopharmacol ; 118: 110038, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36996738

RESUMEN

This study seeks to test the effect of metformin treatment on the outcomes of breast cancer in BALB/c mice bearing 4 T1 breast cancer cells. The survival rate and tumor size of mice were compared, as well as evaluation of the changes of immune cells in spleens and the microenvironment of tumors using flow cytometry and ELISA. Our results demonstrate that metformin prolongs mouse survival. A significant decrease in M2-like macrophages (F4/80+CD206+) was found in mice spleen treated with metformin. The treatment also inhibited monocytic myeloid-derived suppressor cells (M-MDSCs, CD11b+Gr-1+) and regulatory T cells (Tregs, CD4+CD25+Foxp3+). Metformin treatment resulted in an increase in the level of IFN-γ and a decrease in IL-10. Expression of the immune checkpoint molecule PD-1 on T cells was inhibited following treatment. Metformin enhances local antitumor activity in the tumor microenvironment, and our data supports the drug as a candidate for evaluation in the treatment of breast cancer.


Asunto(s)
Metformina , Neoplasias , Animales , Ratones , Proteínas de Punto de Control Inmunitario , Metformina/farmacología , Metformina/uso terapéutico , Inmunidad , Macrófagos , Células Mieloides , Línea Celular Tumoral , Microambiente Tumoral
7.
Oncol Rep ; 49(2)2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36579667

RESUMEN

The epidermal growth factor receptor (EGFR) remains one of the best molecules for developing targeted therapy for multiple human malignancies, including head and neck squamous cell carcinoma (HNSCC). Small molecule inhibitors or antibodies targeting EGFR have been extensively developed in recent decades. Immunotoxin (IT)­based therapy, which combines cell surface binding ligands or antibodies with a peptide toxin, represents another cancer treatment option. A total of 3 diphtheria toxin (DT)­based fusion toxins that target human EGFR­monovalent EGFR IT (mono­EGF­IT), bivalent EGFR IT (bi­EGF­IT), and a bispecific IT targeting both EGFR and interleukin­2 receptor (bis­EGF/IL2­IT) were recently generated by the authors. Improved efficacy and reduced toxicity of bi­EGF­IT compared with mono­EGF­IT in immunocompromised HNSCC mouse models was reported. In the present study, bis­EGF/IL2­IT were generated using a unique DT­resistant yeast expression system and evaluated the in vitro and in vivo efficacy and toxicity of the 3 EGF­ITs in immunocompetent mice. The results demonstrated that while the three EGF­ITs had different efficacies in vitro and in vivo against HNSCC, bi­EGF­IT and bis­EGF/IL2­IT had significantly improved in vivo efficacy and remarkably less off­target toxicity compared with mono­EGF­IT. In addition, bis­EGF/IL2­IT was superior to bi­EGF­IT in reducing tumor size and prolonging survival in the metastatic model. These data suggested that targeting either the tumor immune microenvironment or enhancing the binding affinity could improve the efficacy of IT­based therapy. Bi­EGF­IT and bis­EGF/IL2­IT represent improved candidates for IT­based therapy for future clinical development.


Asunto(s)
Neoplasias de Cabeza y Cuello , Interleucina-2 , Humanos , Animales , Ratones , Carcinoma de Células Escamosas de Cabeza y Cuello/tratamiento farmacológico , Línea Celular Tumoral , Receptores ErbB/metabolismo , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Toxina Diftérica/farmacología , Microambiente Tumoral
8.
Ther Adv Musculoskelet Dis ; 15: 1759720X231158198, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36937823

RESUMEN

Osteoarthritis (OA) is the commonest musculoskeletal disease worldwide, with an increasing prevalence due to aging. It causes joint pain and disability, decreased quality of life, and a huge burden on healthcare services for society. However, the current main diagnostic methods are not suitable for early diagnosing patients of OA. The use of machine learning (ML) in OA diagnosis has increased dramatically in the past few years. Hence, in this review article, we describe the research progress in the application of ML in the early diagnosis of OA, discuss the current trends and limitations of ML approaches, and propose future research priorities to apply the tools in the field of OA. Accurate ML-based predictive models with imaging techniques that are sensitive to early changes in OA ahead of the emergence of clinical features are expected to address the current dilemma. The diagnostic ability of the fusion model that combines multidimensional information makes patient-specific early diagnosis and prognosis estimation of OA possible in the future.

9.
Int Urol Nephrol ; 55(10): 2507-2516, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36964321

RESUMEN

OBJECTIVE: To mechanistically assess the involvement of tenascin-C (TNC) in diabetic nephropathy (DN). METHODS: Renal specimens from DN patients were histopathologically examined, and their TNC expression patterns were evaluated via immunohistochemistry. Additionally, the hereditarily diabetic C57BL/KsJ db/db mice were induced to develop DN via adaptive feeding, and then their renal levels of TNC and ß-catenin were assessed via western blotting and immunohistochemistry. Furthermore, the TNC and ß-catenin levels in primary rat mesangial cells (RMCs) cultured with high glucose levels were assessed via western blotting. In parallel, RMCs cultured with TNC in the presence or absence of the ß-catenin blocker ICG-001 were analyzed for their fibronectin and collagen I levels via immunostaining, and for their fibronectin, α-SMA, vimentin, PDGFR-ß, PCNA, and ß-catenin levels via western blotting. RESULTS: The TNC levels in the specimens were associated with the pathological classification. In these DN specimens, TNC protein was highly detected in the MCs and slightly in the tubulointerstitium. Renal TNC (P < 0.05) and ß-catenin (P < 0.001) were upregulated in db/db vs. db/m mice. High-glucose treatment upregulated TNC (P < 0.01) and ß-catenin (P < 0.05) in RMCs. TNC treatment upregulated fibronectin (P < 0.05), α-SMA (P < 0.01), vimentin (P < 0.05), PCNA (P < 0.05), and ß-catenin (P < 0.05) in RMCs, as assessed via western blotting. Immunohistochemical analysis confirmed the fibronectin upregulation and showed collagen I upregulation. Western-blot results also showed that levels of fibronectin (P < 0.001), α-SMA (P < 0.01), vimentin (P < 0.001), PCNA (P < 0.05), PDGFR-ß (P < 0.05), and ß-catenin (P < 0.01) were lower in RMCs co-treated with TNC and ICG-001 than in TNC-treated cells. Immunofluorescence analysis confirmed the decreased fibronectin level and showed that the collagen I level was also decreased by ICG-001. CONCLUSION: TNC is upregulated in DN and induces MC proliferation and fibrosis through the ß-catenin pathway.


Asunto(s)
Diabetes Mellitus , Nefropatías Diabéticas , Ratas , Ratones , Animales , Nefropatías Diabéticas/metabolismo , Células Mesangiales/metabolismo , Fibronectinas , Tenascina/metabolismo , Vimentina/metabolismo , beta Catenina , Antígeno Nuclear de Célula en Proliferación/metabolismo , Ratones Endogámicos C57BL , Glucosa/farmacología , Glucosa/metabolismo , Fibrosis , Proliferación Celular , Diabetes Mellitus/metabolismo
10.
Curr Med Imaging ; 2023 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-36895124

RESUMEN

OBJECTIVE: The objective of this study is to investigate whether quantitatively measured infrapatellar fat pad (IPFP) signal intensity alteration is associated with joint effusion-synovitis in people with knee osteoarthritis (OA) over two years. METHODS: Among 255 knee OA patients, IPFP signal intensity alteration represented by four measurement parameters [standard deviation of IPFP signal intensity (IPFP sDev), upper quartile value of IPFP high signal intensity region (IPFP UQ (H)), ratio of IPFP high signal intensity region volume to whole IPFP volume (IPFP percentage (H)), and clustering factor of IPFP high signal intensity (IPFP clustering factor (H))] was measured quantitatively at baseline and two-year follow-up using magnetic resonance imaging (MRI). Effusion-synovitis of the suprapatellar pouch and other cavities were measured both quantitatively and semi-quantitatively as effusion-synovitis volume and effusion-synovitis score at baseline and two-year follow-up using MRI. Mixed effects models assessed the associations between IPFP signal intensity alteration and effusion-synovitis over two years. RESULTS: In multivariable analyses, all four parameters of IPFP signal intensity alteration were positively associated with total effusion-synovitis volume and effusion-synovitis volumes of the suprapatellar pouch and of other cavities over two years (all P<0.05). They were also associated with the semi-quantitative measure of effusion-synovitis except for IPFP percentage (H) with effusion-synovitis in other cavities. CONCLUSION: Quantitatively measured IPFP signal intensity alteration is positively associated with joint effusion-synovitis in people with knee OA, suggesting that IPFP signal intensity alteration may contribute to effusion-synovitis and a coexistent pattern of these two imaging biomarkers could exist in knee OA patients.

11.
Front Genet ; 14: 1122955, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37007954

RESUMEN

Objective: To assess the causal effect of systemic iron status by using four biomarkers (serum iron; transferrin saturation; ferritin; total iron-binding capacity) on knee osteoarthritis (OA), hip OA, total knee replacement, and total hip replacement using 2-sample Mendelian randomization (MR) design. Methods: Three instrument sets were used to construct the genetic instruments for the iron status: Liberal instruments (variants associated with one of the iron biomarkers), sensitivity instruments (liberal instruments exclude variants associated with potential confounders), and conservative instruments (variants associated with all four iron biomarkers). Summary-level data for four OA phenotypes, including knee OA, hip OA, total knee replacement, and total hip replacement were obtained from the largest genome-wide meta-analysis with 826,690 individuals. Inverse-variance weighted based on the random-effect model as the main approach was conducted. Weighted median, MR-Egger, and Mendelian randomization pleiotropy residual sum and outlier methods were used as sensitivity MR approaches. Results: Based on liberal instruments, genetically predicted serum iron and transferrin saturation were significantly associated with hip OA and total hip replacement, but not with knee OA and total knee replacement. Statistical evidence of heterogeneity across the MR estimates indicated that mutation rs1800562 was the SNP significantly associated with hip OA in serum iron (odds ratio, OR = 1.48), transferrin saturation (OR = 1.57), ferritin (OR = 2.24), and total-iron binding capacity (OR = 0.79), and hip replacement in serum iron (OR = 1.45), transferrin saturation (OR = 1.25), ferritin (OR = 1.37), and total-iron binding capacity (OR = 0.80). Conclusion: Our study suggests that high iron status might be a causal factor of hip OA and total hip replacement where rs1800562 is the main contributor.

12.
J Clin Med ; 11(16)2022 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-36013035

RESUMEN

Objectives: We aimed to examine whether metformin (MET) use is associated with a reduced risk of total knee arthroplasty (TKA) and low severity of knee pain in patients with knee osteoarthritis (OA) and diabetes and/or obesity. Methods: Participants diagnosed with knee OA and diabetes and/or obesity from June 2000 to July 2019 were selected from the information system of a local hospital. Regular MET users were defined as those with recorded prescriptions of MET or self-reported regular MET use for at least 6 months. TKA information was extracted from patients' surgical records. Knee pain was assessed using the numeric rating scale. Log-binomial regression, linear regression, and propensity score weighting (PSW) were performed for statistical analyses. Results: A total of 862 participants were included in the analyses. After excluding missing data, there were 346 MET non-users and 362 MET users. MET use was significantly associated with a reduced risk of TKA (prevalence ratio: 0.26, 95% CI: 0.15 to 0.45, p < 0.001), after adjustment for age, gender, body mass index, various analgesics, and insurance status. MET use was significantly associated with a reduced degree of knee pain after being adjusted for the above covariates (ß: −0.48, 95% CI: −0.91 to −0.05, p = 0.029). There was a significantly accumulative effect of MET use on the reduced risk of TKA. Conclusion: MET can be a potential therapeutic option for OA. Further clinical trials are needed to determine if MET can reduce the risk of TKA and the severity of knee pain in metabolic-associated OA patients.

13.
Oncogene ; 41(9): 1269-1280, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-35087236

RESUMEN

Recent studies have reported dysbiotic oral microbiota and tumor-resident bacteria in human head and neck squamous cell carcinoma (HNSCC). We aimed to identify and validate oral microbial signatures in treatment-naïve HNSCC patients compared with healthy control subjects. We confirm earlier reports that the relative abundances of Lactobacillus spp. and Neisseria spp. are elevated and diminished, respectively, in human HNSCC. In parallel, we examined the disease-modifying effects of microbiota in HNSCC, through both antibiotic depletion of microbiota in an induced HNSCC mouse model (4-Nitroquinoline 1-oxide, 4NQO) and reconstitution of tumor-associated microbiota in a germ-free orthotopic mouse model. We demonstrate that depletion of microbiota delays oral tumorigenesis, while microbiota transfer from mice with oral cancer accelerates tumorigenesis. Enrichment of Lactobacillus spp. was also observed in murine HNSCC, and activation of the aryl-hydrocarbon receptor was documented in both murine and human tumors. Together, our findings support the hypothesis that dysbiosis promotes HNSCC development.


Asunto(s)
Carcinoma de Células Escamosas de Cabeza y Cuello
14.
Front Cell Infect Microbiol ; 12: 746428, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35521215

RESUMEN

Otitis media (OM), defined as infection or inflammation of the middle ear (ME), remains a major public health problem worldwide. Cholesteatoma is a non-cancerous, cyst-like lesion in the ME that may be acquired due to chronic OM and cause disabling complications. Surgery is required for treatment, with high rates of recurrence. Current antibiotic treatments have been largely targeted to previous culturable bacteria, which may lead to antibiotic resistance or treatment failures. For this study, our goal was to determine the microbiota of cholesteatoma tissue in comparison with other ME tissues in patients with long-standing chronic OM. ME samples including cholesteatoma, granulation tissue, ME mucosa and discharge were collected from patients undergoing tympanomastoidectomy surgery for chronic OM. Bacteria were profiled by 16S rRNA gene sequencing in 103 ME samples from 53 patients. Respiratory viruses were also screened in 115 specimens from 45 patients. Differences in bacterial profiles (beta-diversity) and the relative abundances of individual taxa were observed between cholesteatoma and ME sample-types. Additionally, patient age was associated with differences in overall microbiota composition while numerous individual taxa were differentially abundant across age quartiles. No viruses were identified in screened ME samples. Biodiversity was moderately lower in cholesteatoma and ME discharge compared to ME mucosal tissues. We also present overall bacterial profiles of ME tissues by sample-type, age, cholesteatoma diagnosis and quinolone use, including prevalent bacterial taxa. Our findings will be useful for fine-tuning treatment protocols for cholesteatoma and chronic OM in settings with limited health care resources.


Asunto(s)
Colesteatoma , Microbiota , Otitis Media Supurativa , Otitis Media , Bacterias/genética , Enfermedad Crónica , Humanos , Infección Persistente , ARN Ribosómico 16S/genética
15.
Dev Cell ; 11(3): 301-12, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16950122

RESUMEN

To assess whether Smad signaling affects skin development, we generated transgenic mice in which a Smad antagonist, Smad7, was induced in keratinocytes, including epidermal stem cells. Smad7 transgene induction perturbed hair follicle morphogenesis and differentiation, but accelerated sebaceous gland morphogenesis. Further analysis revealed that independent of its role in anti-Smad signaling, Smad7 bound beta-catenin and induced beta-catenin degradation by recruiting an E3 ligase, Smurf2, to the Smad7/beta-catenin complex. Consequently, Wnt/beta-catenin signaling was suppressed in Smad7 transgenic hair follicles. Coexpression of the Smurf2 and Smad7 transgenes exacerbated Smad7-induced abnormalities in hair follicles and sebaceous glands. Conversely, when endogenous Smad7 was knocked down, keratinocytes exhibited increased beta-catenin protein and enhanced Wnt signaling. Our data reveal a mechanism for Smad7 in antagonizing Wnt/beta-catenin signaling, thereby shifting the skin differentiation program from forming hair follicles to sebaceous glands.


Asunto(s)
Epidermis/patología , Folículo Piloso/fisiología , Proteína smad7/fisiología , Células Madre/fisiología , beta Catenina/metabolismo , Animales , Diferenciación Celular , Proliferación Celular , Regulación hacia Abajo , Epidermis/metabolismo , Folículo Piloso/metabolismo , Humanos , Queratinocitos/metabolismo , Ratones , Ratones Transgénicos , Morfogénesis , Glándulas Sebáceas/fisiología , Transducción de Señal , Proteína smad7/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Proteínas Wnt/metabolismo
16.
J Clin Invest ; 118(8): 2722-32, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18618014

RESUMEN

TGF-beta and its signaling mediators, Smad2, -3, and -4, are involved with tumor suppression and promotion functions. Smad4-/- mouse epidermis develops spontaneous skin squamous cell carcinomas (SCCs), and Smad3-/- mice are resistant to carcinogen-induced skin cancer; however, the role of Smad2 in skin carcinogenesis has not been explored. In the present study, we found that Smad2 and Smad4, but not Smad3, were frequently lost in human SCCs. Mice with keratinocyte-specific Smad2 deletion exhibited accelerated formation and malignant progression of chemically induced skin tumors compared with WT mice. Consistent with the loss of Smad2 in poorly differentiated human SCCs, Smad2-/- tumors were poorly differentiated and underwent epithelial-mesenchymal transition (EMT) prior to spontaneous Smad4 loss. Reduced E-cadherin and activation of its transcriptional repressor Snail were also found in Smad2-/- mouse epidermis and occurred more frequently in Smad2-negative human SCCs than in Smad2-positive SCCs. Knocking down Snail abrogated Smad2 loss-associated EMT, suggesting that Snail upregulation is a major mediator of Smad2 loss-associated EMT. Furthermore, Smad2 loss led to a significant increase in Smad4 binding to the Snail promoter, and knocking down either Smad3 or Smad4 in keratinocytes abrogated Smad2 loss-associated Snail overexpression. Our data suggest that enhanced Smad3/Smad4-mediated Snail transcription contributed to Smad2 loss-associated EMT during skin carcinogenesis.


Asunto(s)
Carcinoma de Células Escamosas/etiología , Carcinoma de Células Escamosas/patología , Neoplasias Cutáneas/etiología , Neoplasias Cutáneas/patología , Proteína Smad2/deficiencia , Animales , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/secundario , Células Cultivadas , Progresión de la Enfermedad , Epitelio/patología , Técnica del Anticuerpo Fluorescente Directa , Eliminación de Gen , Humanos , Queratinocitos/metabolismo , Mesodermo/patología , Ratones , Ratones Noqueados , ARN Interferente Pequeño/metabolismo , Estudios Retrospectivos , Neoplasias Cutáneas/genética , Proteína Smad2/genética , Proteína Smad2/metabolismo
17.
Magn Reson Med ; 66(4): 1033-41, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21394783

RESUMEN

Amide proton transfer (APT) imaging is capable of detecting mobile cellular proteins and peptides in tumor and monitoring pH effects in stroke, through the saturation transfer between irradiated amide protons and water protons. In this work, four healthy subjects, eight brain tumor patients (four with high-grade glioma, one with lung cancer metastasis, and three with meningioma), and four stroke patients (average 4.3 ± 2.5 days after the onset of the stroke) were scanned at 3 T, using different radiofrequency saturation powers. The APT effect was quantified using the magnetization transfer ratio (MTR) asymmetry at 3.5 ppm with respect to the water resonance. At a saturation power of 2 µT, the measured APT-MRI signal of the normal brain tissue was almost zero, due to the contamination of the negative conventional magnetization transfer ratio asymmetry. This irradiation power caused an optimal hyperintense APT-MRI signal in the tumor and an optimal hypointense signal in the stroke, compared to the normal brain tissue. The results suggest that the saturation power of 2 µT is ideal for APT imaging of these two pathologies at 3 T with the existing clinical hardware.


Asunto(s)
Amidas/análisis , Neoplasias Encefálicas/diagnóstico , Imagen por Resonancia Magnética/métodos , Accidente Cerebrovascular/diagnóstico , Análisis de Varianza , Biomarcadores de Tumor/análisis , Neoplasias Encefálicas/secundario , Glioma/diagnóstico , Humanos , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Neoplasias Pulmonares/patología , Meningioma/diagnóstico , Protones , Reproducibilidad de los Resultados
18.
Mol Oncol ; 15(4): 1054-1068, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33540470

RESUMEN

Epidermal growth factor receptor (EGFR) is often overexpressed in head and neck squamous cell carcinoma (HNSCC) and represents a top candidate for targeted HNSCC therapy. However, the clinical effectiveness of current Food and Drug Administration (FDA)-approved drugs targeting EGFR is moderate, and the overall survival rate for HNSCC patients remains low. Therefore, more effective treatments are urgently needed. In this study, we generated a novel diphtheria toxin-based bivalent human epidermal growth factor fusion toxin (bi-EGF-IT) to treat EGFR-expressing HNSCC. Bi-EGF-IT was tested for in vitro binding affinity, cytotoxicity, and specificity using 14 human EGFR-expressing HNSCC cell lines and three human EGFR-negative cancer cell lines. Bi-EGF-IT had increased binding affinity for EGFR-expressing HNSCC compared with the monovalent version (mono-EGF-IT), and both versions specifically depleted EGFR-positive HNSCC, but not EGFR-negative cell lines, in vitro. Bi-EGF-IT exhibited a comparable potency to that of the FDA-approved EGFR inhibitor, erlotinib, for inhibiting HNSCC tumor growth in vivo using both subcutaneous and orthotopic HNSCC xenograft mouse models. When tested in an experimental metastasis model, survival was significantly longer in the bi-EGF-IT treatment group than the erlotinib treatment group, with a significantly reduced number of metastases compared with mono-EGF-IT. In addition, in vivo off-target toxicities were significantly reduced in the bi-EGF-IT treatment group compared with the mono-EGF-IT group. These results demonstrate that bi-EGF-IT is more effective and markedly less toxic at inhibiting primary HNSCC tumor growth and metastasis than mono-EGF-IT and erlotinib. Thus, the novel bi-EGF-IT is a promising drug candidate for further development.


Asunto(s)
Toxina Diftérica/uso terapéutico , Factor de Crecimiento Epidérmico/uso terapéutico , Carcinoma de Células Escamosas de Cabeza y Cuello/tratamiento farmacológico , Animales , Línea Celular Tumoral , Clorhidrato de Erlotinib/uso terapéutico , Humanos , Ratones , Ratones Endogámicos NOD , Ratones SCID , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteínas Recombinantes de Fusión/uso terapéutico , Ensayos Antitumor por Modelo de Xenoinjerto
19.
J Cell Commun Signal ; 14(2): 175-192, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31925646

RESUMEN

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignant tumors with poor prognosis. Aryl hydrocarbon receptor (AHR) is a ligand-dependent transcription factor and emerging evidence shows it is associated with tumor initiation and promotion. However, the relationship between AHR and ESCC is not clear and it is meaningful to explore whether AHR could be a therapeutic target. In the present study, immunohistochemistry was performed to determine AHR expression levels in ESCC tissues. Knockdown of AHR expression in ESCC cell lines genetically and modulation of AHR by 3, 3'-diindolylmethane (DIM) pharmacologically both in vitro and in vivo were utilized to examine the corresponding alterations in cell growth, migration and invasion. Our study indicated that AHR expression levels were elevated in ESCC and associated with poor prognosis. Both knockdown and modulation of AHR inhibited tumor progression through down-regulating expression levels of PCNA, Bcl-2, Cyclin D1, MMP1, MMP2, MMP9 and up-regulating expression levels of Bax, Cleaved-Caspase 3. Our findings also indicated that repressing COX2/PGE2/STAT3 axis exerted inhibitory effects on ESCC both in vitro and in vivo assays. Taken together, AHR plays the key role in ESCC progression and targeting AHR as a therapeutic strategy with DIM is deserved for further exploration.

20.
Mol Oncol ; 14(1): 139-158, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31600013

RESUMEN

Recurrence and metastasis are the major causes of mortality in head and neck squamous cell carcinoma (HNSCC). It is suggested that cancer stem cells (CSCs) play pivotal roles in recurrence and metastasis. Thus, a greater understanding of the mechanisms of CSC regulation may provide opportunities to develop novel therapies for improving survival by controlling recurrence or metastasis. Here, we report that overexpression of the gene encoding the catalytic subunit of PI3K (PIK3CA), the most frequently amplified oncogene in HNSCC, promotes epithelial-to-mesenchymal transition and enriches the CSC population. However, PIK3CA is not required to maintain these traits and inhibition of the phosphatidylinositol 3-kinase (PI3K) signaling pathway paradoxically promotes CSC population. Molecular analysis revealed that overexpression of PIK3CA activates multiple receptor tyrosine kinases (RTKs), in which ephrin receptors (Ephs), tropomyosin receptor kinases (TRK) and mast/stem cell growth factor receptor (c-Kit) contribute to maintain CSC population. Accordingly, simultaneous inhibition of these RTKs using a multi-kinase inhibitor ponatinib has a superior effect at eliminating the CSC population and reduces metastasis of PIK3CA-overexpressing HNSCC cells. Our result suggests that co-targeting of Ephs, TRKs and the c-Kit pathway may be effective at eliminating the PI3K-independent CSC population, thereby providing potential targets for future development of a novel anti-CSC therapeutic approach for HNSCC patients, particularly for patients with PIK3CA amplification.


Asunto(s)
Fosfatidilinositol 3-Quinasa Clase I/metabolismo , Neoplasias de Cabeza y Cuello/metabolismo , Imidazoles/farmacología , Recurrencia Local de Neoplasia/metabolismo , Células Madre Neoplásicas/metabolismo , Piridazinas/farmacología , Transducción de Señal/genética , Carcinoma de Células Escamosas de Cabeza y Cuello/metabolismo , Animales , Antineoplásicos/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Proliferación Celular/genética , Fosfatidilinositol 3-Quinasa Clase I/antagonistas & inhibidores , Fosfatidilinositol 3-Quinasa Clase I/genética , Transición Epitelial-Mesenquimal/genética , Técnicas de Silenciamiento del Gen , Neoplasias de Cabeza y Cuello/enzimología , Neoplasias de Cabeza y Cuello/genética , Neoplasias de Cabeza y Cuello/patología , Humanos , Ratones , Ratones Endogámicos C57BL , Recurrencia Local de Neoplasia/genética , Células Madre Neoplásicas/efectos de los fármacos , Células Madre Neoplásicas/patología , Inhibidores de Proteínas Quinasas/farmacología , ARN Interferente Pequeño , Proteínas Tirosina Quinasas Receptoras , Transducción de Señal/efectos de los fármacos , Carcinoma de Células Escamosas de Cabeza y Cuello/enzimología , Carcinoma de Células Escamosas de Cabeza y Cuello/genética , Carcinoma de Células Escamosas de Cabeza y Cuello/secundario , Regulación hacia Arriba , Ensayos Antitumor por Modelo de Xenoinjerto
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