Virginia Polytechnic Institute(VPI)研究人员披露,他们经遗传工程获得了产生葡糖脑苷酯酶(GCR)的烟草植株。对此,Genzyme公司立即作出反应,很快消除了它的股东们的顾虑,并声称,该公司的药物(世界上价格最高的药物之一)仍具有强大的市...Virginia Polytechnic Institute(VPI)研究人员披露,他们经遗传工程获得了产生葡糖脑苷酯酶(GCR)的烟草植株。对此,Genzyme公司立即作出反应,很快消除了它的股东们的顾虑,并声称,该公司的药物(世界上价格最高的药物之一)仍具有强大的市场优势,不会受到什么威胁。展开更多
AIM: To observe the gene silencing mediated by the specific shRNA targeted against β-catenin and its effect on cell proliferation and cycle distribution in the human colon cancer cell line Colo205. METHODS: Two shRNA...AIM: To observe the gene silencing mediated by the specific shRNA targeted against β-catenin and its effect on cell proliferation and cycle distribution in the human colon cancer cell line Colo205. METHODS: Two shRNA plasmid vectors against β-catenin were constructed and transfected into Colo205 cells with LipofectamineTM2000. The down-regulations of β-catenin, c-myc and cyclinD1 expressions were detected by RT-PCR and western blot analysis. The cell proliferation inhibitions were determined by MTT assay and soft agar colony formation assay. The effect of these two β-catenin shRNAs on cell cycle distribution and apoptosis was examined by flow cytometry. RESULTS: These two shRNA vectors targeted against β-catenin efficiently suppressed the expression of β-catenin and its down stream genes, c-myc and cyclinD1. The expression inhibition rates were around 40%-50% either at the mRNA or at the protein level. The shRNA-mediated gene silencing of β-catenin resulted in significant inhibition of cell growth both on the culture plates and in the soft agar. Moreover, the cancer cells showed significant G0/G1 arrest and increased apoptosis at 72 h post transfection due to gene silencing. CONCLUSION: These specific shRNAs targeted against β-catenin could have a gene silencing effect and block the WNT signaling pathway. They could inhibit cell growth, increase apoptosis, and induce cell cycle arrest in Colo205 cells. ShRNA interference against β-catenin is of potential value in gene therapy of colon cancer.展开更多
AIM： To investigate the prevalence of hepatitis C virus （HCV） genotypes in Serbia and Montenegro and their influence on some clinical characteristics in patients with chronic HCV infection. METHODS： A total of 164...AIM： To investigate the prevalence of hepatitis C virus （HCV） genotypes in Serbia and Montenegro and their influence on some clinical characteristics in patients with chronic HCV infection. METHODS： A total of 164 patients was investigated. Complete history, route of infection, assessment of alcohol consumption, an abdominal ultrasound, standard biochemical tests and liver biopsy were done. Gene sequencing of 5＇ NTR type-specific PCR or commercial kits was performed for HCV genotyping and subtyping. The SPSS for Windows （version 10.0） was used for univariate regression analysis with further multivariate analysis. RESULTS： The genotypes 1, 2, 3, 4, 1b3a and 1b4 were present in 57.9%, 3.7%, 23.2%, 6.7%, 6.7% and 1.8% of the patients, respectively. The genotype 1 （mainly the subtype 1b） was found to be independent of age in subjects older than 40 years, high viral load, more severe necro-inflammatory activity, advanced stage of fibrosis, and absence of intravenous drug abuse. The genotype 3a was associated with intravenous drug abuse and the age below 40. Multivariate analysis demonstrated age over 40 and intravenous drug abuse as the positive predictive factors for the genotypes lb and 3a, respectively.CONCLUSION： In Serbia and Montenegro, the genotypes 1b and 3a predominate in patients with chronic HCV infection. The subtype lb is characteristic of older patients, while the genotype 3a is common in drug abusers. Association of the subtype lb with advanced liver disease, higher viral load and histological activity suggests earlier infection with this genotype and eventually its increased pathogenicity.展开更多
AIM: To clarify whether Lysophosphatidic acid (LPA) activates the nuclear translocation of nuclear factor-κB (NF-κB) in pancreatic cancer. METHODS: Panc-1, a human pancreatic cancer cell line, was used throughout th...AIM: To clarify whether Lysophosphatidic acid (LPA) activates the nuclear translocation of nuclear factor-κB (NF-κB) in pancreatic cancer. METHODS: Panc-1, a human pancreatic cancer cell line, was used throughout the study. The expression of LPA receptors was confirmed by reverse-transcript polymerase chain reaction (RT-PCR). Cytosolic free calcium was measured by fluorescent calcium indicator fura-2, and the localization of NF-κB was visualized by immunofluorescent method with or without various agents, which effect cell signaling. RESULTS: Panc-1 expressed LPA receptors, LPA1, LPA2 and LPA3. LPA caused the elevation of cytosolic free calcium dose-dependently. LPA also caused the nuclear translocation of NF-κB. Cytosolic free calcium was attenuated by pertussis toxin (PTX) and U73122, an inhibitor of phospholipase C. The translocation of NF-κB was similarly attenuated by PTX and U73122, but phorbol ester, an activator of protein kinase C, alone did not translocate NF-κB. Furthermore, the translocation of NF-κB was completely blocked by Ca2+ chelator BAPTA-AM. Thapsigargin, an endoplasmic- reticulum Ca2+-ATPase pump inhibitor, also promoted the translocation of NF-κB. Staurosporine, a proteinkinase C inhibitor, attenuated translocation of NF-κB induced by LPA. CONCLUSION: These findings suggest that protein kinase C is activated endogenously in Panc-1, and protein kinase C is essential for activating NF-κB with cytosolic calcium and that LPA induces the nuclear translocation of NF-κB in Panc-1 by mobilizing cytosolic free calcium.展开更多
基金Supported by the Guangdong Provincial Scientific Research Grants: No. 2004B30301002, No. 2007B030702012 and No. 04300330
文摘AIM: To observe the gene silencing mediated by the specific shRNA targeted against β-catenin and its effect on cell proliferation and cycle distribution in the human colon cancer cell line Colo205. METHODS: Two shRNA plasmid vectors against β-catenin were constructed and transfected into Colo205 cells with LipofectamineTM2000. The down-regulations of β-catenin, c-myc and cyclinD1 expressions were detected by RT-PCR and western blot analysis. The cell proliferation inhibitions were determined by MTT assay and soft agar colony formation assay. The effect of these two β-catenin shRNAs on cell cycle distribution and apoptosis was examined by flow cytometry. RESULTS: These two shRNA vectors targeted against β-catenin efficiently suppressed the expression of β-catenin and its down stream genes, c-myc and cyclinD1. The expression inhibition rates were around 40%-50% either at the mRNA or at the protein level. The shRNA-mediated gene silencing of β-catenin resulted in significant inhibition of cell growth both on the culture plates and in the soft agar. Moreover, the cancer cells showed significant G0/G1 arrest and increased apoptosis at 72 h post transfection due to gene silencing. CONCLUSION: These specific shRNAs targeted against β-catenin could have a gene silencing effect and block the WNT signaling pathway. They could inhibit cell growth, increase apoptosis, and induce cell cycle arrest in Colo205 cells. ShRNA interference against β-catenin is of potential value in gene therapy of colon cancer.
文摘AIM： To investigate the prevalence of hepatitis C virus （HCV） genotypes in Serbia and Montenegro and their influence on some clinical characteristics in patients with chronic HCV infection. METHODS： A total of 164 patients was investigated. Complete history, route of infection, assessment of alcohol consumption, an abdominal ultrasound, standard biochemical tests and liver biopsy were done. Gene sequencing of 5＇ NTR type-specific PCR or commercial kits was performed for HCV genotyping and subtyping. The SPSS for Windows （version 10.0） was used for univariate regression analysis with further multivariate analysis. RESULTS： The genotypes 1, 2, 3, 4, 1b3a and 1b4 were present in 57.9%, 3.7%, 23.2%, 6.7%, 6.7% and 1.8% of the patients, respectively. The genotype 1 （mainly the subtype 1b） was found to be independent of age in subjects older than 40 years, high viral load, more severe necro-inflammatory activity, advanced stage of fibrosis, and absence of intravenous drug abuse. The genotype 3a was associated with intravenous drug abuse and the age below 40. Multivariate analysis demonstrated age over 40 and intravenous drug abuse as the positive predictive factors for the genotypes lb and 3a, respectively.CONCLUSION： In Serbia and Montenegro, the genotypes 1b and 3a predominate in patients with chronic HCV infection. The subtype lb is characteristic of older patients, while the genotype 3a is common in drug abusers. Association of the subtype lb with advanced liver disease, higher viral load and histological activity suggests earlier infection with this genotype and eventually its increased pathogenicity.
基金The Research Committee of Intractable Pancreatic Diseases, provided by the Ministry of Health, Labour, and Welfare, Japan, No. 50253448
文摘AIM: To clarify whether Lysophosphatidic acid (LPA) activates the nuclear translocation of nuclear factor-κB (NF-κB) in pancreatic cancer. METHODS: Panc-1, a human pancreatic cancer cell line, was used throughout the study. The expression of LPA receptors was confirmed by reverse-transcript polymerase chain reaction (RT-PCR). Cytosolic free calcium was measured by fluorescent calcium indicator fura-2, and the localization of NF-κB was visualized by immunofluorescent method with or without various agents, which effect cell signaling. RESULTS: Panc-1 expressed LPA receptors, LPA1, LPA2 and LPA3. LPA caused the elevation of cytosolic free calcium dose-dependently. LPA also caused the nuclear translocation of NF-κB. Cytosolic free calcium was attenuated by pertussis toxin (PTX) and U73122, an inhibitor of phospholipase C. The translocation of NF-κB was similarly attenuated by PTX and U73122, but phorbol ester, an activator of protein kinase C, alone did not translocate NF-κB. Furthermore, the translocation of NF-κB was completely blocked by Ca2+ chelator BAPTA-AM. Thapsigargin, an endoplasmic- reticulum Ca2+-ATPase pump inhibitor, also promoted the translocation of NF-κB. Staurosporine, a proteinkinase C inhibitor, attenuated translocation of NF-κB induced by LPA. CONCLUSION: These findings suggest that protein kinase C is activated endogenously in Panc-1, and protein kinase C is essential for activating NF-κB with cytosolic calcium and that LPA induces the nuclear translocation of NF-κB in Panc-1 by mobilizing cytosolic free calcium.
