RESUMEN
BACKGROUND: Alzheimer's disease (AD) is clinically characterized as a progressive cognitive impairment and behavioral disorder. Pathological hallmarks of AD include extracellular senile plaques (SPs), intracellular neurofibrillary tangles (NFTs) and massive neuronal loss. Although the exact cause of AD is not well understood, a mounting body of evidence has demonstrated that the pathogenesis of AD is associated with oxidative stress, neu-roinflammation, and amyloid beta (Aß) induced neural apoptosis. Moreover, overexpression of ß-secretase 1 (BACE1), Aß, mammalian target of rapamycin (mTOR), and Tau proteins are closely related to cognitive symptoms in AD. Studies have demonstrated that artemether, an antimalarial drug with acceptable side effects, possesses protective effects against neuroinflammation and oxidative stress. Importantly, artemether can easily penetrate the blood brain barrier, thereby representing an ideal drug candidate for AD treatment. METHODS: The effect of artemether on memory protection and the associated molecular mechanisms were investigated in an Aß25-35 induced cognitive impairments rat model. RESULTS: Results of the in vivo study showed that oral administration of artemether significantly attenuated Aß25-35-induced cognitive impairment in rats. Results of the in vitro study revealed that artemether significantly downregulated the endogenous expression of Aß, BACE1, mTOR, and Tau proteins in N2a cells. CONCLUSIONS: The beneficial effect of artemether against Aß 25-35-induced cognitive impairments was attributable to the downregulation of the expression of Aß, BACE1, mTOR, and Tau proteins, suggesting the potential of artemether as an effective, neuronal protective, and multi-targeted drug candidate for AD treatment.
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Enfermedad de Alzheimer , Disfunción Cognitiva , Enfermedad de Alzheimer/inducido químicamente , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/genética , Secretasas de la Proteína Precursora del Amiloide/genética , Péptidos beta-Amiloides , Animales , Arteméter , Ácido Aspártico Endopeptidasas/genética , Disfunción Cognitiva/inducido químicamente , Disfunción Cognitiva/tratamiento farmacológico , Fragmentos de Péptidos , Ratas , Serina-Treonina Quinasas TOR , Proteínas tauRESUMEN
In tumor research, the occurrence and origin of tumors are the fundamental problems. In the 1970s, the basic discussion of the developmental biology problem of tumors was proposed, and it was believed that tumorigenesis is closely related to developmental biology. Tumors are abnormal biological structures in organisms, and their biological behavior is very similar to that of the early embryo. Many tumor-related genes also serve regulatory roles in the normal development and differentiation of embryos. However, it remains unclear whether gene expression in early embryos has any similarities with tumor cells. In this study, to compare the similarities and differences in gene expression between early embryos and tumor cells, reverse transcription-quantitative PCR was conducted to determine and compare the relative expression levels of nine tumor-related genes in the brain glioma cell line, T98G, and in the early embryo of Spodoptera litura, which is fast-growing, low-cost, easily accessible and easy to observe. The expression of tumor-related genes in early embryos and the similarity of regulatory mechanisms between early embryonic development and tumor growth were explored. In conclusion, tumor growth may be regarded as an abnormal embryogenic activation that happens in the organs of adult individuals.
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The incidence and associated mortality of lung cancer in tin miners in Gejiu County and farmers in Xuanwei Country, Yunnan Province have been very high in the world. Current published literatures on the molecular mechanisms of lung cancer initiation and progression in Gejiu and Xuanwei County are still controversial. Studies confirmed that microRNA-34a (miR-34a) functioned as a vital tumor suppressor in tumorigenesis and progression. However, the role and precise mechanisms of miR-34a and its regulatory gene network in initiation and progression of lung cancer in Gejiu and Xuanwei County, Yunnan Province, have not been elucidated. In the current study, we first found that miR-34a was downregulated in Gejiu lung squamous carcinoma YTMLC-90, Xuanwei lung adenocarcinoma XWLC-05, and other non-small cell lung carcinoma (NSCLC) cell lines, and miR-34a overexpression inhibited cell proliferation, migration and invasion, as well as induced cell apoptosis in YTMLC-90 and XWLC-05 cells. Our findings revealed that miR-34a is critical and cannot be considered as the area-specific non-coding RNA in initiation and progression of lung cancer in Gejiu and Xuanwei County. Next we revealed that miR-34a overexpression suppressed lung cancer growth and metastasis partially via increasing PTEN but reducing CDK6 expression that might lead to subsequent inactivation of PI3K/AKT pathway. Furthermore, our findings demonstrated that YY1 functioned as a tumor suppressor gene in initiation and progression of lung cancer in Gejiu and Xuanwei County. In conclusion, our findings in the study confirmed that miR-34a overexpression could simultaneously suppress tumor growth and metastasis and play a vital role in tumorigenesis and progression of NSCLC via increasing PTEN and YY1 expression, but decreasing CDK6. Most interestingly, our findings also raised doubts about the current ideas about these area-specific diseases.
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Lung cancer is the most prevalent and observed type of cancer in Xuanwei County, Yunnan, South China. Lung cancer in this area is called Xuanwei lung cancer. However, its pathogenesis remains largely unknown. To date, a number of studies have shown that microRNA (miR)218 functions as a tumor suppressor in multiple types of cancer. However, the role of miR218 and its regulatory gene network in Xuanwei lung cancer have yet to be investigated. The current study identified that the expression levels of miR218 in XWLC05 cells were markedly lower compared with those in immortalized lung epithelial BEAS2B cells. The present study also demonstrated that overexpression of miR218 could decrease cell proliferation, invasion, viability and migration in Xuanwei lung cancer cell line XWLC05 and NSCLC cell line NCIH157. Additionally, the results revealed that overexpression of miR218 could induce XWLC05 and NCIH157 cell apoptosis by arresting the cell cycle at G2/M phase. Finally, the present study demonstrated that overexpression of miR218 could lead to a significant increase in phosphatase and tensin homolog (PTEN) and YY1 transcription factor (YY1), and a decrease in Bcell lymphoma 2 (BCL2) and BMI1 protooncogene, polycomb ring finger (BMI1) at the mRNA and protein level in XWLC05 and NCIH157 cell lines. However, we did not observe any remarkable difference in the roles of miR218 and miR218mediated regulation of BCL2, BMI1, PTEN and YY1 expression in the progression of Xuanwei lung cancer. In conclusion, miR218 could simultaneously suppress cell proliferation and tumor invasiveness and induce cell apoptosis by increasing PTEN and YY1 expression, while decreasing BCL2 and BMI1 in Xuanwei lung cancer. The results demonstrated that miR218 might serve a vital role in tumorigenesis and progression of Xuanwei lung cancer and overexpression of miR218 may be a novel approach for the treatment of Xuanwei lung cancer.
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Carcinoma de Pulmón de Células no Pequeñas/genética , Regulación hacia Abajo , Neoplasias Pulmonares/genética , MicroARNs/genética , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Ciclo Celular , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Supervivencia Celular , China , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias Pulmonares/metabolismo , Fosfohidrolasa PTEN/genética , Fosfohidrolasa PTEN/metabolismo , Complejo Represivo Polycomb 1/genética , Complejo Represivo Polycomb 1/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Factor de Transcripción YY1/genética , Factor de Transcripción YY1/metabolismoRESUMEN
To explore the inhibitive effect of artemether on glioma growth and angiogenesis in brain tumor bearing SD rat. MTT assay was used to evaluate the inhibitory effect of artemether treatment on C6 glioma cells. Forty SD rats which were subcutaneous planted with SD rat C6 glioma cell to establish SD rat orthotopic glioma model were divided resourcefully into 5 groups. each group was 8 rats. Length-path (a mm) and short-path (b mm) of tumor each rat was measured. Tumor volume was calculated using the following formula: V (mm(3)) = a(2)bpi/6. Microvessel density (MVD) in different therapy groups was significantly lower than that in normal saline control group and brain glioma volume in different therapy groups was significantly smaller than that in normal saline control group. There were remarkably inhibitory effects of artmeter on brain glioma growth and angiogenesis in SD rats and the mechanism that artemether inhibited brain glioma growth might be penetrating the blood-brain barrier and inhibiting angiogenesis.
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Artemisininas/farmacología , Neoplasias Encefálicas/tratamiento farmacológico , Glioma/tratamiento farmacológico , Neovascularización Patológica/tratamiento farmacológico , Inhibidores de la Angiogénesis/administración & dosificación , Inhibidores de la Angiogénesis/farmacocinética , Inhibidores de la Angiogénesis/farmacología , Animales , Arteméter , Artemisininas/administración & dosificación , Artemisininas/farmacocinética , Barrera Hematoencefálica/metabolismo , Neoplasias Encefálicas/fisiopatología , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Glioma/fisiopatología , Microvasos/efectos de los fármacos , Microvasos/patología , Trasplante de Neoplasias , Neovascularización Patológica/fisiopatología , Ratas , Ratas Sprague-Dawley , Factores de TiempoRESUMEN
A new bis-cyclometalated iridium(III) complex [Ir(dmabt)(2)(bipy)][PF(6)] (3) (dmabt = 4-(benzo[d]thiazol-2-yl)-N,N-dimethylaniline, bipy = 2,2'-bipyridine) has been synthesized and fully characterized. The complex 3 has been determined by X-ray structure analyses which shows that the central iridium(III) ion assumes distorted octahedral geometry. The photoluminescence spectrum exhibits orange emission maximum at 612 nm with quantum yield of 17% at 298 K. The frontier molecular orbital diagrams and the spin-allowed singlet-singlet electronic transitions of 3 have been calculated with density functional theory (DFT) and time-dependent DFT (TD-DFT), and the UV-Vis spectra are discussed based on the theoretical calculations.