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STAT1 is involved in signal transduction in the EPOinduced hel cells

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Cell Research 1998年第2期8卷 105-117页

作者： JIANG CHU CHANG YUN GUI JIE FAN XIAO DA TANG RUO LAN QIAO(Shanghai Institute of Cell Biology, Chinese Academy ofSciences, Shanghai 200031, China )(Dept. of Urology, Shanghai First People,s Hospital,Shanghai 200081, China) Shanghai Institute of Cell Biology Chinese Academy of Sciences Shangai China Dept. of Urology Shanghai First People's Hospital Shangai China

Erythropoietin (EPO) is the ma jor regulator of mammalian erythropoisis, which stimulates the growth and differentiation of hematopoietic cells through interaction with its receptor (EPO-R). Here we use hel cells (a human erythro-leukemia cell line) as a model to elucidate the pathway of signal transduction in the EPO-induced hel cells. our data show that the EPOR (EPO receptor) on the surface of hel cells interacts with the Janus tyrosine protein kinase (Jak2) to transduce intracellular signals through phosphorylation of cytoplasmic proteins in EPO-treated hel cells. Both STAT1 and STAT5 in this cell line are tyrosine-phosphorylated and translocated to nucleus following the binding of EPO to hel ***, the binding of both STAT1 and STAT5 proteins to specific DNA elements (SIE and PIE elements) is revealed in an EPO-dependent manner. Our data demonstrate that the pathway of signal transduction following the binding of EPO to hel cells is similar to immature erythroid cell from the spleen of mice infected with anemia strain of Friend virus.

关键词： Erythropoietin hel cells signal transduction

The apoptosis of hel cells induced by hydroxyurea

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Cell Research 1997年第1期7卷 91-97页

作者： GUI CHANG YUN CHU JIANG HENG YUE XIE RUO LAN QIAN(Shanghai Institute of Cell Biology, Chinese Academy of Sciences, Shanghai 200031) Shanghai Institute of Cell Biology Chinese Academy of Sciences Shanghai

Hydroxyurea has been used to synchronize cultured cells to S-phase and used to treat patients with sicklecell anemia. Recently, we found that hydroxyurea can induce the apoptosis of hel (human erythroleukemia) *** induced hel cells showed ultrastructurally chromatin condensation with regular crescents at the nuclear edges and apoptotic bodies. However, the cells of K562, another human erythroleukemia cell line, did not show such morphological changes. Under fluoroscope, the hel cells after induction often displayed a clear reduction in nuclear diameter and nuclear chromatin cleavage and condensation and the presence of nuclear ring and apoptotic bodies. Analysis with flow cytometry showed that the percentage of apoptotic cells is about 30-40% after hel cells were induced by hydroxyurea for 3 days. DNA ladder can be observed by electrophoretic analysis.

关键词： hel cells hydroxyurea apoptosis

Ameliorated Chrysotile-induced DNA Damage in Human Embryo Lung cells by Surface Modification of Chrysotile With Rare Earth Compounds

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Biomedical and Environmental Sciences 2001年第3期14卷 220-228页

作者： FANJING－GUANG WANGQI－EN 等 NationalCenterforOccupationalSafetyScienceandTechnology Beijing100029China DepartmentofOccupationalHealth SchoolofPublicHealthBeijingMedicalUniversityBeijing100083China

Objective In view of the fact that asbestos is not only a key occupational hazard, but also an important environmental pollutant, it is necessary to develop a proper method to decrease the carcinogenecity of asbestos fibers. This study was designed to determine if the surface modification of chrysotile asbestos fiber (CAF) with rare earth compounds (REC) can ameliorate CAF-induced DNA damages in human embryo lung (hel) cells. Methods After incubation with REC solution at different concentrations at room temperature for 1 h, natural and REC-pretreated CAF was added to cell culture at various doses. At the selected time as the experiment designed, DNA damages of the hel cells were detected by Unscheduled DNA Synthesis (UDS) and Single Cell Gel Electrophoresis (SCGE) assays. Results The UDS induced by natural CAF was elevated with the increase of CAF doses. There was a good dose-response relationship between the UDS and the amount of CAF in the medium and the coefficient of correlation (R) was 0.958 at Phel cells may be partly mediated by oxygen derivatives, and the surface modification of CAF with REC might hide critical sites on the fiber surface, thereby reducing the fiber-mediated production of oxygen derivation and lowering the CAF-induced UDS and DNA chain breakage in hel cells.

关键词： DNA Damage Surface Modification surface modification hel cells Unscheduled DNA Synthesis rare earth compounds occupational hazard Gel Electrophoresis room temperature asbestos fiber cell culture Single Cell

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Chrysotile-induced Cell Transformation and Transcri-ptional Changes of c-myc Oncogene in Human Embryo Lung cells

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Biomedical and Environmental Sciences 2000年第3期13卷 163-169页

It has been verified that asbestos induce neoplastic transformation of several rodent cell lines in vitro. Very little information is available, however, on asbestos induced human cell line transformation and oncogene activation in the development of asbestos induced cell transformation. This study was designed to investigate the induction of cell transformation and transcriptional changes of the c myc oncogene by chrysotile asbestos fibers (CAF) in human embryo lung (hel) cells. Surface modified CAF soaked in aluminium citrate (AC), rare earth compounds (REC) or sodium selenite (SS) solutions were used to observe the effects of surface modification on chrysotile induced cell transformation and transcriptional changes in the c myc oncogene. The results showed that the natural CAF caused dose dependent increases in transformed foci, along with increased transcription of the c myc oncogene in hel cells, while the pretreated CAF induced fewer transformed foci and less c myc oncogene transcription than the natural CAF. The percent inhibition of equivalent AC, REC and SS were 38.9%, 50.0%, 33.3% (for transformation focus), 81.6%, 69.5%, 89.9% (for c myc oncogene transcription), respectively. These results indicated that CAF may induce cell transformation and transcriptional changes and that the carcinogenicity of CAF might be reduced by pretreatment of CAF with the above mentioned compounds.

关键词： cell transformation neoplastic transformation surface modification chrysotile asbestos cell lines hel cells in vitro

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