RESUMEN
Phospholipids are pivotal polar lipids in human milk and essential for infants' growth and development, especially in the brain and cognitive development. Its content and composition are affected by multiple factors and there exist discrepancies in different studies. In this study, we determined five major phospholipids classes (phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, phosphatidylcholine, and sphingomyelin) in 2270 human milk samples collected from 0 to 400 days postpartum in six regions of China. The high-performance liquid chromatography coupled with an evaporative light scattering detector (HPLC-ELSD) was performed to quantify the phospholipids. Total phospholipid median (IQR) content was in a range between 170.38 ± 96.52 mg/L to 195.69 ± 81.80 mg/L during lactation and was higher concentrated in colostrum milk and later stage of lactation (after 200 days postpartum) compared with that in the samples collected between 10 to 45 days postpartum. Variations in five major sub-class phospholipids content were also observed across lactation stages (phosphatidylethanolamine: 52.61 ± 29.05 to 59.95 ± 41.74 mg/L; phosphatidylinositol: 17.65 ± 10.68 to 20.38 ± 8.55 mg/L; phosphatidylserine: 15.98 ± 9.02 to 22.77 ± 11.17 mg/L; phosphatidylcholine: 34.13 ± 25.33 to 48.64 ± 19.73 mg/L; sphingomyelin: 41.35 ± 20.31 to 54.79 ± 35.26 mg/L). Phosphatidylethanolamine (29.18-32.52%), phosphatidylcholine (19.90-25.04%) and sphingomyelin (22.39-29.17%) were the dominant sub-class phospholipids in Chinese breast milk during the whole lactation period. These results updated phospholipids data in Chinese human milk and could provide evidence for better development of secure and effective human milk surrogates for infants without access to breast milk.
Asunto(s)
Leche Humana , Fosfolípidos , Animales , Femenino , Humanos , Lactante , Lactancia , Leche/química , Leche Humana/química , Fosfatidilcolinas , Fosfatidilinositoles , Fosfatidilserinas/análisis , Fosfolípidos/química , Esfingomielinas/análisisRESUMEN
BACKGROUND: We previously reported that the anti-transforming growth factor-beta1 (TGF-beta1) ribozymes directed by T7 and CMV promoters could reverse the character of activated hepatic stellate cells (HSCs) in vitro and improve fibrotic pathology in vivo. However, nonspecific elimination of the effects of TGF-beta1 without selectivity might have unfavorable consequences, such as overwhelming inflammation, tissue necrosis, etc. AIMS: To establish an activated-HSC-specific gene silencing method and validate its feasibility for antifibrosis in vitro. METHODS: An artificial intronic microRNA (miRNA) expression system was established, containing three parts: (1) a 1,074-bp SM-alpha actin promoter SMP8, which is a kind of RNA polymerase II promoter and has no activity in normal liver-derived cells but is switched on during the activation of HSCs, (2) intron1 modified by inserting an artificial pre-miRNA sequence against TGF-beta1, and (3) report gene enhanced green fluorescent proteins (EGFP). The feasibility of this system for artificial microRNA expression was validated through microRNA detection by real-time polymerase chain reaction (PCR). Alteration of biological characteristics of HSCs with the anti-TGF-beta1 miRNAs was preliminarily evaluated by measuring the expression levels of TGF-beta1 and its downstream molecules, including collagen I, matrix metalloproteinase 2 (MMP2), tissue inhibitor of metalloproteinase 1 (TIMP-1), etc. RESULTS: The microRNA expression system could successfully produce mature anti-TGF-beta1 miRNAs in an activated-HSC-specific manner. The microRNA-induced inhibition rate of TGF-beta1 reached 70% and above. Accompanied by TGF-beta1 suppression, its downstream targets such as collagen I, MMP2, TIMP-1, etc. were also significantly downregulated in vitro. CONCLUSIONS: Activated-HSC-cell-specific gene silencing could be induced well by the artificial intronic microRNA expression system to realize antifibrosis in vitro.
Asunto(s)
Silenciador del Gen , Genes Sintéticos , Células Estrelladas Hepáticas , Cirrosis Hepática/prevención & control , MicroARNs , Factor de Crecimiento Transformador beta1/genética , Animales , Células Cultivadas , Colágeno Tipo I/genética , Estudios de Factibilidad , Intrones , Cirrosis Hepática/genética , Masculino , Metaloproteinasa 2 de la Matriz/genética , Reacción en Cadena de la Polimerasa , Ratas , Ratas Wistar , Inhibidor Tisular de Metaloproteinasa-1/genética , TransfecciónRESUMEN
BACKGROUND & OBJECTIVE: Alpha-fetoprotein (AFP) promoter-driven target gene could be specifically expressed in AFP-positive hepatoma. Escherichia coli purine nucleoside phosphorylase/6-methylpurine-2-deoxyriboside (PNP/MeP-dR) suicide gene system has powerful killing effects on tumor cells. This study was to investigate the specific killing effect of PNP/MeP-dR suicide gene system driven by an AFP promoter, AF0.3, on AFP-positive hepatoma cells. METHODS: Inserting PNP gene into pAF0.3, a eukaryotic expression vector containing PNP gene, pAF0.3/PNP, was constructed. Then it was transfected into AFP-positive HepG2 and AFP-negative SMMC7721 hepatoma cell lines, respectively. Two cell lines HepG2/AF0.3-PNP and SMMC7721/AF0.3-PNP, stably transfected with PNP gene, were obtained with G418 selection. The expression of PNP gene was detected by reverse transcription-polymerase chain reaction (RT-PCR). The proliferation of HepG2/AF0.3-PNP and SMMC7721/AF0.3-PNP cells was determined with trypan blue exclusion. The sensitivity of the cells to MeP-dR and the bystander effects were assessed with MTT assay and flow cytometry (FCM). The enzymatic activities of PNP gene products were determined with high performance liquid chromatography (HPLC). RESULTS: Whether hypoxia or normoxia, HepG2/AF0.3-PNP cells were sensitive to MeP-dR, whereas SMMC7721/AF0.3-PNP cells were not. Under both conditions, obvious cytotoxic effects on HepG2 cells were observed when the proportion of HepG2/AF0.3-PNP cells in the mixture reached 25%. But there were no similar effects on SMMC7721 cells under the same conditions. HPLC assay showed that the product of PNP gene driven by AF0.3 promoter could convert a spot of MeP-dR into 6-MP in HepG2 cells, but not in SMMC7721 cells. CONCLUSION: PNP/MeP-dR system, driven by AF0.3 promoter, has powerful killing effect on AFP-positive hepatoma HepG2 cells.
Asunto(s)
Apoptosis , Genes Transgénicos Suicidas , Neoplasias Hepáticas/patología , Purina-Nucleósido Fosforilasa/genética , alfa-Fetoproteínas/genética , Efecto Espectador , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patología , Hipoxia de la Célula , Línea Celular Tumoral , Proliferación Celular , Terapia Genética , Humanos , Neoplasias Hepáticas/metabolismo , Regiones Promotoras Genéticas , Nucleósidos de Purina/metabolismo , Nucleósidos de Purina/farmacología , Purina-Nucleósido Fosforilasa/metabolismo , Transfección , alfa-Fetoproteínas/metabolismoRESUMEN
AIM: To investigate the prediction value of radiosensitivity of hepatocarcinoma cells for apoptosis and micronucleus assay. METHODS: Clonogenic assay, flow cytometry, and CB micronuclei assay were used to survey the cell survival rate, radiation-induced apoptosis and micronucleus frequency of hepatocarcinoma cell lines SMMC-7721, HL-7702, and HepG2 after being irradiated by X-ray at the dosage ranging 0-8 Gy. RESULTS: After irradiation, there was a dose-effect relationship between micronucleus frequency and radiation dosage among the three cell lines (P<0.05). A positive relationship was observed between apoptosis and radiation dosage among the three cell lines. The HepG2 cells had a significant correlation (P<0.05) but apoptosis incidence had a negative relationship with micronucleus frequency. There was a positive relationship between apoptosis and radiation dosage and the correlation between SMMC-7721 and HL-7702 cell lines had a significant difference (P<0.01). After irradiation, a negative relationship between cell survival rate and radiation dosages was found among the three cell lines (P<0.01). There was a positive relationship between cell survival rate and micronucleus frequency (P<0.01). No correlation was observed between apoptosis and cell survival rate. CONCLUSION: The radiosensitivity of hepatocarcinoma cells can be reflected by apoptosis and micronuclei. Detection of apoptosis and micronuclei could enhance the accuracy for predicting radiosensitivity.
Asunto(s)
Apoptosis , Carcinoma Hepatocelular , Línea Celular Tumoral/fisiología , Línea Celular Tumoral/efectos de la radiación , Neoplasias Hepáticas , Pruebas de Micronúcleos , Tolerancia a Radiación , Línea Celular Tumoral/citología , Supervivencia Celular , Relación Dosis-Respuesta en la Radiación , Humanos , Micronúcleos con Defecto Cromosómico , Valor Predictivo de las Pruebas , Rayos XRESUMEN
AIM: To establish the cell survival curve for primary hepatic carcinoma cells and to study the relationship between SF(2) of primary hepatic carcinoma cells and radiosensitivity. METHODS: Hepatic carcinoma cells were cultured in vitro using 39 samples of hepatic carcinoma at stages II-IV. Twenty-nine samples were cultured successfully in the fifth generation cells. After these cells were radiated with different dosages, the cell survival ratio and SF(2) were calculated by clonogenic assay and SF(2) model respectively. The relationship between SF(2) and the clinical pathological feature was analyzed. RESULTS: Twenty-nine of thirty-nine samples were successfully cultured. After X-ray radiation of the fifth generation cells with 0, 2, 4, 6, 8 Gy, the cell survival rate was 41%, 36.5%, 31.0%, 26.8%, and 19%, respectively. There was a negative correlation between cell survival and irradiation dosage (r = -0.973, P<0.05). SF(2) ranged 0.28-0.78 and correlated with the clinical stage and pathological grade of hepatic carcinoma (P<0.05). There was a positive correlation between SF(2) and D0.5 (r = 0.773, P<0.05). CONCLUSION: SF(2) correlates with the clinical stage and pathological grade of hepatic carcinoma and is a marker for predicting the radiosensitivity of hepatic carcinomas.
Asunto(s)
Carcinoma Hepatocelular/patología , Carcinoma Hepatocelular/radioterapia , Supervivencia Celular , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/radioterapia , Tolerancia a Radiación , Adulto , Anciano , Animales , Técnicas de Cultivo de Célula , Relación Dosis-Respuesta en la Radiación , Humanos , Persona de Mediana Edad , Estadificación de Neoplasias , Células Tumorales CultivadasRESUMEN
AIM: To study the antitumor effect of combined gene therapy of endostatin and interleukin 12 (IL-12) with polyvinylpyrrolidone (PVP) on mouse transplanted hepatoma. METHODS: Mouse endostatin eukaryotic plasmid (pSecES) with a mouse Igkappa signal sequence inside and mouse IL-12 eukaryotic plasmid (pmIL-12) were transfected into BHK-21 cells respectively. Endostatin and IL-12 were assayed by ELISA from the supernant and used to culture endothelial cells and spleen lymphocytes individually. Proliferation of the latter was evaluated by MTT. H22 cells were inoculated into the leg muscle of mouse, which was injected intratumorally with pSecES/PVP, pmIL-12/PVP or pSecES+pmIL-12/PVP repeatedly. Tumor weight, serum endostatin and serum IL-12 were assayed. Tumor infiltrating lymphocytes, tumor microvessel density and apoptosis of tumor cells were also displayed by HE staining, CD31 staining and TUNEL. RESULTS: Endostatin and IL-12 were secreted after transfection, which could inhibit the proliferation of endothelial cells or promote the proliferation of spleen lymphocytes. Tumor growth was highly inhibited by 91.8% after injection of pSecES+pmIL-12/PVP accompanied by higher serum endostatin and IL-12, more infiltrating lymphocytes, fewer tumor vessels and more apoptosis cells compared with injection of pSecES/PVP, pmIL-12/PVP or vector/PVP. CONCLUSION: Mouse endostatin gene and IL-12 gene can be expressed after intratumoral injection with PVP. Angiogenesis of hepatoma can be inhibited synergisticly, lymphocytes can be activated to infiltrate, and tumor cells are induced to apoptosis. Hepatoma can be highly inhibited or eradiated.
Asunto(s)
Adyuvantes Inmunológicos/genética , Inhibidores de la Angiogénesis/genética , Carcinoma Hepatocelular/terapia , Endostatinas/genética , Terapia Genética , Interleucina-12/genética , Neoplasias Hepáticas/terapia , Povidona/uso terapéutico , Animales , Carcinoma Hepatocelular/tratamiento farmacológico , Línea Celular , Terapia Combinada , Humanos , Inmunoterapia , Neoplasias Hepáticas/tratamiento farmacológico , Masculino , Ratones , Ratones Endogámicos BALB CRESUMEN
Cyclooxygenase-2 (cox-2) overexpression has been observed in several types of human cancers and has been implicated in carcinogenesis. To elucidate the role of cox-2 in esophageal carcinogenesis, we evaluated the expression of cox-2 in normal squamous epithelium squamous epithelial dysplasia (n=47), and squamous cell carcinoma of the esophagus (n=86) by immunohistochemistry, reverse transcription-PCR assay, and western blotting. A significant overexpression of cox-2 was observed in esophageal squamous dysplasia and squamous cell carcinoma compared with normal squamous epithelium. The immunoreactive score of cox-2 expression, an index determined by intensity and positivity of cox-2 staining, was 0.71 +/- 0.46 (mean +/- SD) in normal squamous esophagus, 2.19 +/- 1.79 in squamous epithelial dysplasia, and 2.67 +/- 1.77 in squamous cell carcinoma. The results of immunohistochemistry were confirmed by a reverse transcription-PCR assay and western blotting analysis. Cox-2 expression level was correlated with proliferation activity assessed by proliferating cell nuclear antigen (PCNA) index and MIB-1 index in dysplastic lesion (r=0.55, P<0.01 with PCNA and r=0.72, P<0.01 with MIB-1) and carcinoma (r=0.56, P<0.01 with PCNA and r=0.72, P<0.01 with MIB-1). Elevated cox-2 expression was associated with high p53 expression (p<0.001) but not with clinicopathological features including age, sex, tumor size, histological grade, lymph node metastasis, and TNM stage. The results indicated that cox-2 may be involved in an early stage of squamous carcinogenesis of the esophagus, and that cox-2 overexpression was related to cell proliferation in esophageal squamous dysplasia and squamous cell carcinoma.
Asunto(s)
Carcinoma de Células Escamosas/enzimología , Neoplasias Esofágicas/enzimología , Regulación Neoplásica de la Expresión Génica , Isoenzimas/genética , Prostaglandina-Endoperóxido Sintasas/genética , Análisis de Varianza , Western Blotting , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/cirugía , División Celular , Ciclooxigenasa 2 , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/patología , Neoplasias Esofágicas/cirugía , Esófago/enzimología , Regulación Enzimológica de la Expresión Génica , Humanos , Inmunohistoquímica , Antígeno Ki-67/análisis , Proteínas de la Membrana , Estadificación de Neoplasias , ARN Mensajero/genética , Valores de Referencia , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transcripción GenéticaRESUMEN
AIM: To establish a luciferase reporter cell line that responds dioxin-like chemicals (DLCs) and on this basis to evaluate its characteristics and application in the determination of DLCs. METHODS: A recombinant luciferase reporter plasmid was constructed by inserting dioxin-responsive element (DREs) and MMTV promoter segments into the pGL(3)-promoter plasmid immediately upstream of the luciferase gene, which was structurally demonstrated by fragment mapping analysis in gel electrophoresis and transfected into the human hepatoma cell line HepG(2), both transiently and stably, to identify the inducible expression of luciferase by 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD). The time course, responsive period, sensitivity, structure-inducibility and dose-effect relationships of inducible luciferase expression to DLCs was dynamically observed in HepG(2) cells stably transfected by the recombinant vector (HepG(2)-Luc) and compared with that assayed by ethoxyresorufin-O-deethylase (EROD) in non-transfected HepG(2) cells (HepG(2)-wt). RESULTS: The inducible luciferase expression of HepG(2)-Luc cells was noted in a time-, dose-, and AhR-dependent manner, which peaked at 4 h and then decreased to a stable level at 14 h after TCDD treatment. The responsiveness of HepG(2)-Luc cells to TCDD induction was decreased with culture time and became undetectable at 10th month of HepG(2)-Luc cell formation. The fact that luciferase activity induced by 3, 3', 4, 4'-PCB in HepG(2)-Luc cells was much less than that induced by TCDD suggests a structure-inducibility relationship existing among DLCs. Within the concentrations from 3.5 x 10(-12) to 5 x 10(-9) mol/L, significant correlations between TCDD doses and EROD activities were observed in both HepG(2)-luc and HepG(2)-wt cells. The correlation between TCDD doses from 1.1 x 10(-13) to 1 x 10(-8) mol/L and luciferase activities was also found to be significant in HepG(2)-luc cells (r=0.997, P<0.001), but not in their HepG(2)-wt counterparts. For the comparison of the enzyme responsiveness between cell lines to TCDD, the luciferase sensitivity and reproducibility in HepG(2)-luc cells were both better than that of EROD in HepG(2)-wt cells, the former was at 1.1 x 10(-13) mol/L and 3.5 x 10(-12) mol/L, and the coefficients of variation (CV) of the latter was 15-30 % and 22-38 %, respectively. CONCLUSION: The luciferase expression of HepG(2)-luc cells established in the present study could sensitively respond to the DLCs stimulation and might be a prospective tool for the determination of DLCs.
Asunto(s)
Carcinoma Hepatocelular , Dioxinas/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Neoplasias Hepáticas , Luciferasas/genética , Línea Celular Tumoral , Genes Reporteros , Humanos , Proteínas Recombinantes/genéticaRESUMEN
OBJECTIVE: To improve the chemically-activated luciferase expression (CALUX) bioassay for detection of dioxin-like chemicals (DLCs) based on the toxicity mechanisms of DLCs. METHODS: A recombinant vector was constructed and used to transfect human hepatoma (HepG2). The expression of this vector was 10-100 folds higher than that of pGL2 used in previous experiments. The transfected cells showed aromatic hydrocarbon receptor (AhR)-meditated luciferase gene expression. The reliability of luciferase induction in this cell line as a reporter of AhR-mediated toxicity was evaluated, the optimal detection time was examined and a comparison was made by using the commonly used ethoxyresoufin-O-deethylase (EROD) activity induction assay. RESULTS: The results suggested that the luciferase activity in recombinant cells was peaked at about 4 h and then decreased to a stable activity by 14 h after TCDD treatment. The detection limit of this cell line was 0.11 pmol/L, or 10-fold lower than in previous studies, with a linear range from 1 to 100 pmol/L, related coefficient of 0.997, and the coefficient of variability (CV) of 15-30%. CONCLUSION: The luciferase induction is 30-fold more sensitive than EROD induction, the detection time is 68 h shorter and the detection procedure is also simpler.