CAJ | 학술논문

目的: 研究转化生长因子β_1 (TGF-β_1)作用于NB4细胞后的细胞凋亡情况、细胞周期改变及内源性TGF-β_1、P27~(Kip1)、cyclin E及bcl-2 mRNA水平的变化.方法: 瑞氏-吉姆萨染色观察凋亡细胞形态学的变化;流式细胞术检测细胞周期和凋亡;半定量RT-PCR技术检测内源性TGF-β_1、P27~(Kip1)、cyclin E以及bcl-2的mRNA水平.结果: TGF-β_1能抑制NB4细胞的生长,促进NB4细胞的凋亡.5 μg/L TGF-β_1使NB4细胞阻滞在G1期.外源性TGF-β_1浓度<5 μg/L时,内源性TGF-β_1的mRNA表达上调,外源性TGF-β_1浓度为10 μg/L时,内源性TGF-β_1 mRNA表达下调.5 μg/L TGF-β_1可使P27~(Kip1)表达上调、cyclin E、bcl-2表达下调.结论: TGF-β_1可诱导NB4细胞凋亡,引起细胞周期分布异常;外源性TGF-β_1可能通过(1)上调内源性TGF-β_1,从而使下游因子P27~(Kip1)高表达以诱导NB4细胞凋亡;(2)TGF-β_1直接抑制了cyclin E的表达,或者通过调高P27~(Kip1)的表达反馈抑制cyclin E的活性,进而导致细胞周期阻滞;(3)通过下调bcl-2而诱导NB4细胞凋亡.高浓度的外源性TGF-β_1可拮抗内源性TGF-β_1表达,可能与其导致TGF-β_1受体突变,或存在TGF-β_1受体靶点过饱和现象有关.
목적: 연구전화생장인자β_1 (TGF-β_1)작용우NB4세포후적세포조망정황、세포주기개변급내원성TGF-β_1、P27~(Kip1)、cyclin E급bcl-2 mRNA수평적변화.방법: 서씨-길모살염색관찰조망세포형태학적변화;류식세포술검측세포주기화조망;반정량RT-PCR기술검측내원성TGF-β_1、P27~(Kip1)、cyclin E이급bcl-2적mRNA수평.결과: TGF-β_1능억제NB4세포적생장,촉진NB4세포적조망.5 μg/L TGF-β_1사NB4세포조체재G1기.외원성TGF-β_1농도<5 μg/L시,내원성TGF-β_1적mRNA표체상조,외원성TGF-β_1농도위10 μg/L시,내원성TGF-β_1 mRNA표체하조.5 μg/L TGF-β_1가사P27~(Kip1)표체상조、cyclin E、bcl-2표체하조.결론: TGF-β_1가유도NB4세포조망,인기세포주기분포이상;외원성TGF-β_1가능통과(1)상조내원성TGF-β_1,종이사하유인자P27~(Kip1)고표체이유도NB4세포조망;(2)TGF-β_1직접억제료cyclin E적표체,혹자통과조고P27~(Kip1)적표체반궤억제cyclin E적활성,진이도치세포주기조체;(3)통과하조bcl-2이유도NB4세포조망.고농도적외원성TGF-β_1가길항내원성TGF-β_1표체,가능여기도치TGF-β_1수체돌변,혹존재TGF-β_1수체파점과포화현상유관.
AIM:To study the effects of transforming growth factor-β_1 (TGF-β_1) on cell apoptosis,cell cycle,production of endogenous TGF-β_1,expressions of P27~(Kip1),cyclin E and bcl-2 mRNA levels in NB4 cells. METHODS:Apoptotic morphological changes were observed by Wright-Giemsa staining. Cell cycle and apoptosis were detected with flow cytometry. Semiquantitative RT-PCR was used to examine the mRNA levels of endogenous TGF-β_1,P27~(Kip1),cyclin E and bcl-2. RESULTS:TGF-β_1 significantly restrained the growth and promoted the apoptosis of NB4 cells. The blockage of NB4 cells treated by TGF-β_1 at concentration of 5 μg/L was in G1 phase. Endogenous TGF-β_1 mRNA expression in NB4 cells was up-regulated when the concentration of exogenous TGF-β_1 was <5 μg/L. Meanwhile,the expression of endogenous TGF-β_1 mRNA was down-regulated when the concentration of exogenous TGF-β_1 was 10 μg/L. After treated with TGF-β_1 at concentration of 5 μg/L,P27~(Kip1) mRNA expression in NB4 cells was up-regulated,cyclin E and bcl-2 were reduced. CONCLUSION:TGF-β_1 is able to induce apoptosis and cell cycle distribution abnormally in NB4 cells by (1) Up-regulation of endogenous TGF-β_1,so that NB4 cells was induced into apoptosis through consequently high expression of P27~(Kip1). (2) TGF-β_1 may lead to cell cycle arrest by inhibiting the expression of cyclin E directly,or by inhibiting the activity of cyclin E through the increased expression of P27~(Kip1). (3) Down-regulation of bcl-2 induces apoptosis of NB4 cells.