IM To determine whether antisense insulinlike growth factorI(IGFI) gene can modulate CEA and AFP expression in human hepatoma cells (HepG2).METHODS Transfection of HepG2 cells was accomplished using Lipofectin reage...IM To determine whether antisense insulinlike growth factorI(IGFI) gene can modulate CEA and AFP expression in human hepatoma cells (HepG2).METHODS Transfection of HepG2 cells was accomplished using Lipofectin reagent. Northern blot analysis confirmed the antisense IGFI RNA of the transfected cells. CEA and AFP levels were measured using radioimmunoassay.RESULTS Human hepatoma cell lines (HepG2) were transfected with antisense IGFI gene. Northern blot analysis confirmed that antisense IGFI RNA was expressed in the transfected cells. The effect of antisense IGFI gene on CEA and AFP expression was demonstrated by the fact that the CEA and AFP levels in the supernatant of transfected cell culture were significantly lower as compared with the parent cells, 〔CEA 70μg/L±076μg/L and 329μg/L±180μg/L (P<005) and AFP 5363μg/L±602μg/L and 90μg/L±526μg/L (P<001), respectively〕.CONCLUSION The malignant potentiality of the transfected cells was partially suppressed. Antisense IGFI gene can modulate the expression of CEA and AFP in human hepatoma cell lines (HepG2).展开更多
Background Human embryonic stem cells can propagate indefinitely in vitro and are able to differentiate into derivatives of all three embryonic germ layers. The excitement surrounding human embryonic stem cells lies l...Background Human embryonic stem cells can propagate indefinitely in vitro and are able to differentiate into derivatives of all three embryonic germ layers. The excitement surrounding human embryonic stem cells lies largely in their potential to produce specialized cells that can be used for transplant therapies. However, further investigation requires additional cell lines with varying genetic background. Therefore, efforts to derive and establish more human embryonic stern cell lines are highly warranted. Methods Surplus embryos （blastocysts） from donors were used to isolate the inner cell mass by immunosurgery. All cells were cultured continuously on irradiated murine embryonic fibroblasts feed layer and likely human embryonic stem cell colonies were subsequently characterized by cell surface marker staining, karyotyping and teratoma formation. Results Two human embryonic stern cell lines （SYSU-1 and SYSU-2） were established from surplus embryos. The two lines express several pluripotency markers including alkaline phosphatase, SSEA- 4, Tra-1-60, Oct-4, Nanog and Rex-1. They remain in undifferentiated state with normal karyotype after prolonged passages and can form embryoid bodies in vitro and teratoma in vivo. Conclusion Two new human embryonic stem cell lines have been established from surplus embryos. They can be used to understand selfrenewal and differentiating mechanisms and provide more choices for regenerative medicine.展开更多
Background The prospects of using immature CD8a^＋ dendritic cells （DC2） to establish transplant immunologic tolerance and treatments for autoimmune diseases in the future are promising. However, the methods for ind...Background The prospects of using immature CD8a^＋ dendritic cells （DC2） to establish transplant immunologic tolerance and treatments for autoimmune diseases in the future are promising. However, the methods for inducing DC2 are still being explored. The present study was aimed to investigate the optimal in vitro conditions for preparing large numbers of predominant DC2 from murine bone marrow cells. Methods Three groups of bone marrow cells cultured under different conditions were examined, namely a cytokine-induced experimental group （cytokine group）, a control group with a low concentration of granulocyte-macrophage colony stimulating factor （GM-CSF, low GM-CSF group） and a control group without endogenous cytokines. The cytokine group was cultured with 5 ng/ml GM-CSF, 25 ng/ml Fit3 ligand （FIt3L）, 20 ng/ml interleukin 4 （IL-4） and 100 ng/ml stem cell factor （SCF）. The low GM-CSF control group was cultured with 0.4 ng/ml GM-CSF, 25 ng/ml FIt3L and 100 ng/ml SCF, without IL-4. The control group without exogenous cytokines was cultured without additional cytokines. All cells were cultured at 37℃ under 5% CO2. On days 3, 7 and 16, 4-color flow cytometry was carried out to analyze the cell phenotypes, and the total cell numbers were counted to analyze the cell yields. Phase-contrast microscopy was used to observe the cell morphologies. Results The cytokine group exhibited higher proportions of typical immature CD8a^＋ DC, especially on day 3, but the total cell number and DC2 proportion decreased during prolonged culture. The low GM-CSF control group showed the same tendencies as the cytokine group on days 16 and 22, but produced higher total cell numbers （P 〈0.05） with lower DC2 proportions and cell numbers. The control group without exogenous cytokines spontaneously generated a certain proportion of DC2, but with low total cell and DC2 numbers that decreased rapidly, especially during prolonged culture （days 7 and 16, P 〈0.05）, Conclusions Culture in the presence of 5 ng/ml GM-CSF, 25 ng/ml FIt3L, 20 ng/ml IL-4 and 100 ng/ml SCF can rapidly induce large quantities of predominant immature CD8a^＋ DC from murine bone marrow cells. Therefore, these represent optimal culture conditions for preparing murine immature DC2 in vitro.展开更多
文摘IM To determine whether antisense insulinlike growth factorI(IGFI) gene can modulate CEA and AFP expression in human hepatoma cells (HepG2).METHODS Transfection of HepG2 cells was accomplished using Lipofectin reagent. Northern blot analysis confirmed the antisense IGFI RNA of the transfected cells. CEA and AFP levels were measured using radioimmunoassay.RESULTS Human hepatoma cell lines (HepG2) were transfected with antisense IGFI gene. Northern blot analysis confirmed that antisense IGFI RNA was expressed in the transfected cells. The effect of antisense IGFI gene on CEA and AFP expression was demonstrated by the fact that the CEA and AFP levels in the supernatant of transfected cell culture were significantly lower as compared with the parent cells, 〔CEA 70μg/L±076μg/L and 329μg/L±180μg/L (P<005) and AFP 5363μg/L±602μg/L and 90μg/L±526μg/L (P<001), respectively〕.CONCLUSION The malignant potentiality of the transfected cells was partially suppressed. Antisense IGFI gene can modulate the expression of CEA and AFP in human hepatoma cell lines (HepG2).
基金This work was supported by the National Basic Research Program of China （973 Program） （No. 2001CB509904） the Key Scientific and Technological Projects of Guangdong Province （No. 2003A3020103, 2005A30201001）+1 种基金 the Key Scientific and Technological Projects of Guangzhou City （No. 2002U13E0011） National Natural Science Foundation of China （No 30571891, 30671023）.
文摘Background Human embryonic stem cells can propagate indefinitely in vitro and are able to differentiate into derivatives of all three embryonic germ layers. The excitement surrounding human embryonic stem cells lies largely in their potential to produce specialized cells that can be used for transplant therapies. However, further investigation requires additional cell lines with varying genetic background. Therefore, efforts to derive and establish more human embryonic stern cell lines are highly warranted. Methods Surplus embryos （blastocysts） from donors were used to isolate the inner cell mass by immunosurgery. All cells were cultured continuously on irradiated murine embryonic fibroblasts feed layer and likely human embryonic stem cell colonies were subsequently characterized by cell surface marker staining, karyotyping and teratoma formation. Results Two human embryonic stern cell lines （SYSU-1 and SYSU-2） were established from surplus embryos. The two lines express several pluripotency markers including alkaline phosphatase, SSEA- 4, Tra-1-60, Oct-4, Nanog and Rex-1. They remain in undifferentiated state with normal karyotype after prolonged passages and can form embryoid bodies in vitro and teratoma in vivo. Conclusion Two new human embryonic stem cell lines have been established from surplus embryos. They can be used to understand selfrenewal and differentiating mechanisms and provide more choices for regenerative medicine.
文摘Background The prospects of using immature CD8a^＋ dendritic cells （DC2） to establish transplant immunologic tolerance and treatments for autoimmune diseases in the future are promising. However, the methods for inducing DC2 are still being explored. The present study was aimed to investigate the optimal in vitro conditions for preparing large numbers of predominant DC2 from murine bone marrow cells. Methods Three groups of bone marrow cells cultured under different conditions were examined, namely a cytokine-induced experimental group （cytokine group）, a control group with a low concentration of granulocyte-macrophage colony stimulating factor （GM-CSF, low GM-CSF group） and a control group without endogenous cytokines. The cytokine group was cultured with 5 ng/ml GM-CSF, 25 ng/ml Fit3 ligand （FIt3L）, 20 ng/ml interleukin 4 （IL-4） and 100 ng/ml stem cell factor （SCF）. The low GM-CSF control group was cultured with 0.4 ng/ml GM-CSF, 25 ng/ml FIt3L and 100 ng/ml SCF, without IL-4. The control group without exogenous cytokines was cultured without additional cytokines. All cells were cultured at 37℃ under 5% CO2. On days 3, 7 and 16, 4-color flow cytometry was carried out to analyze the cell phenotypes, and the total cell numbers were counted to analyze the cell yields. Phase-contrast microscopy was used to observe the cell morphologies. Results The cytokine group exhibited higher proportions of typical immature CD8a^＋ DC, especially on day 3, but the total cell number and DC2 proportion decreased during prolonged culture. The low GM-CSF control group showed the same tendencies as the cytokine group on days 16 and 22, but produced higher total cell numbers （P 〈0.05） with lower DC2 proportions and cell numbers. The control group without exogenous cytokines spontaneously generated a certain proportion of DC2, but with low total cell and DC2 numbers that decreased rapidly, especially during prolonged culture （days 7 and 16, P 〈0.05）, Conclusions Culture in the presence of 5 ng/ml GM-CSF, 25 ng/ml FIt3L, 20 ng/ml IL-4 and 100 ng/ml SCF can rapidly induce large quantities of predominant immature CD8a^＋ DC from murine bone marrow cells. Therefore, these represent optimal culture conditions for preparing murine immature DC2 in vitro.
