Effect of hypoxia inducible factor1-α inhibitor on reversal of multidrug resistance of K562/A02 cell line

Objective To study the reversal effect of the hypoxia inducible factor( HIF)-1α inhibitor,YC-1 ,on muitidrug resistance of K562/A02 cells and its mechanism. Methods Pre- and post- incubation with adriamycin (ADM) alone or in combination with YC-1 for 48 h, the proliferation capacity of K562/A02 and K562 cells were evaluated by MTT assay. The apoptosis rate of K562/A02 cells after treated with 0,5,10 and 20 μmol/L YC-1 alone or in combination with 1 mg/L ADM and intracellular ADM concentration were analyzed by flow cytometry(FCM). The mRNA levels of HIF-1α and mdr1 genes were determined by semi-quantitative RT-PCR. The protein levels of HIF-1α and P-glycoprotein (P-gp) were detected by Western blot. Results The IC50 of ADM for K562 and K562/A02 cells were ( 1.56 ± 0.07 ) mg/L and (42.98 ±3.15) mg/L respectively. The resistance of K562/A02 cells to ADM was 27.55- fold higher of that of K562cells. After treatment with YC-1 (5μmol/L, 10μmol/L, 20 μmol/L) for 48h, the resistances of K562/A02cells to ADM were 24.63-, 16.38- and 10.71- fold increase respectively. After treatment of K562/A02 cell with YC-1(0 μmol/L, 5 μmol/L, 10 μmol/L, 20 μmoL/L) alone or in combination with 1 mg/L ADM for 48 h, the apoptotic rates were ( 1.9 ± 0. 9) %, (4.9 ± 0. 9 ) %, ( 5.8 ± 1.1 ) %, and ( 9.3 ± 1.4 ) % and(2.3 ± 0.7 ) %, (8.2 ± 1.2) %, ( 19.0 ± 1.7 ) %, and ( 34.5 ± 2.4 ) % respectively. The intracellular flucorescence intensity of ADM were 232 ±33, 1300 ±219, 1961 ±240 and 3342 ±269 in the combined treatment group. With the increase in YC-1 concentration, the levels of mdr1 mRNA reduced, while that ofHIF-1α mRNA had no obvious change.Furthermore.the expressions of HIF-1α and P-gp were also decreased in K562/A02 cells.Conclusion YC-1,as a HIF-1 inhibitor,cau reverse multidrug resistance of K562/A02cells through down-regulating HIF-1α and p-gp.     

Effect of hypoxia inducible factor1-α inhibitor on reversal of multidrug resistance of K562/A02 cell line

Objective To study the reversal effect of the hypoxia inducible factor( HIF)-1α inhibitor,YC-1 ,on muitidrug resistance of K562/A02 cells and its mechanism. Methods Pre- and post- incubation with adriamycin (ADM) alone or in combination with YC-1 for 48 h, the proliferation capacity of K562/A02 and K562 cells were evaluated by MTT assay. The apoptosis rate of K562/A02 cells after treated with 0,5,10 and 20 μmol/L YC-1 alone or in combination with 1 mg/L ADM and intracellular ADM concentration were analyzed by flow cytometry(FCM). The mRNA levels of HIF-1α and mdr1 genes were determined by semi-quantitative RT-PCR. The protein levels of HIF-1α and P-glycoprotein (P-gp) were detected by Western blot. Results The IC50 of ADM for K562 and K562/A02 cells were ( 1.56 ± 0.07 ) mg/L and (42.98 ±3.15) mg/L respectively. The resistance of K562/A02 cells to ADM was 27.55- fold higher of that of K562cells. After treatment with YC-1 (5μmol/L, 10μmol/L, 20 μmol/L) for 48h, the resistances of K562/A02cells to ADM were 24.63-, 16.38- and 10.71- fold increase respectively. After treatment of K562/A02 cell with YC-1(0 μmol/L, 5 μmol/L, 10 μmol/L, 20 μmoL/L) alone or in combination with 1 mg/L ADM for 48 h, the apoptotic rates were ( 1.9 ± 0. 9) %, (4.9 ± 0. 9 ) %, ( 5.8 ± 1.1 ) %, and ( 9.3 ± 1.4 ) % and(2.3 ± 0.7 ) %, (8.2 ± 1.2) %, ( 19.0 ± 1.7 ) %, and ( 34.5 ± 2.4 ) % respectively. The intracellular flucorescence intensity of ADM were 232 ±33, 1300 ±219, 1961 ±240 and 3342 ±269 in the combined treatment group. With the increase in YC-1 concentration, the levels of mdr1 mRNA reduced, while that ofHIF-1α mRNA had no obvious change.Furthermore.the expressions of HIF-1α and P-gp were also decreased in K562/A02 cells.Conclusion YC-1,as a HIF-1 inhibitor,cau reverse multidrug resistance of K562/A02cells through down-regulating HIF-1α and p-gp.     

米非司酮逆转K562/A02细胞多药耐药的研究

目的研究孕激素拮抗剂米非司酮对白血病多药耐药细胞K562／A02的逆转作用及其机制。方法MTT法检测米非司酮作用72h后K562／A02细胞增殖及其对阿霉素杀伤敏感性的变化；流式细胞术检测米非司酮作用前后K562／A02细胞表面P糖蛋白的表达和细胞内柔红霉素的浓度；免疫组化法观察米非司酮作用前后K562／A02细胞凋亡相关蛋白bcl-2、Bax、caspase-3的表达；RT—PCR检测米非司酮作用后对K562／A02细胞内葡萄糖神经酰胺合成酶（GcS）mRNA表达的影响。结果2．5、5．0和10．0μmol／L米非司酮不抑制K562／A02细胞的增殖，但上述浓度的米非司酮作用后K562／A02细胞对阿霉素的敏感性较前分别增强了1．68、4．17和10．71倍。K562／A02细胞表面P糖蛋白的表达为（49．03±5．32）％，10μmol／L米非司酮作用72h后降低到（28．60±2．13）％（P〈0．01）；K562／A02细胞内柔红霉素的浓度为（61．07±8．61）％，而10μmol／L米非司酮作用后升高到（92．72±3．48）％（P〈0．01）。经10μmol／L米非司酮作用后，bcl-2蛋白表达由（56±9）％降低到（37±6）％（P〈0．05）；Bax蛋白由（40±5）％升高到（87±10）％（P〈0．01）；caspase-3蛋白则由（36±7）％升高到（89±6）％（P〈0．01）。RT—PCR结果显示K562／A02细胞GcS mRNA的表达较K562细胞明显升高，10μmol／L米非司酮能明显降低K562／A02细胞内GcS mRNA的表达。结论米非司酮可逆转白血病K562／A02细胞的多药耐药，且具有剂量依赖性。10μmol／L米非司酮能明显逆转白血病K562／A02细胞的多药耐药，其机制与降低P糖蛋白的水平，调节凋亡相关蛋白bcl-2、Bax、caspase-3的表达，降低GcS mRNA有关。     

鼠尾草酸逆转K562/A02细胞多药耐药的机制研究

目的 探讨鼠尾草酸(Canosic acid,CA)对人类白血病多药耐药(MDR)细胞系K562/A02细胞的逆转作用及机制.方法 MTT法测定CA作用前后K562/A02细胞对阿霉素(ADM)的敏感性.流式细胞术(FCM)和激光扫描共聚焦显微镜(LSCM)测定细胞内ADM的平均荧光强度,计算细胞内ADM浓度.半定量RT-PCR检测细胞mdr1 mRNA表达水平.采用流式细胞术和Western blot 检测细胞膜P糖蛋白(P-gp)表达.结果 CA可将ADM对K562/A02细胞的IC50值由16.31μg/ml降至1.35μg/ml,逆转倍数为12.08倍.流式细胞术检测结果表明CA可将K562/A02细胞内ADM的荧光强度由17.05提高到60.53(P<0.01).LSCM结果显示CA可恢复ADM在K562/A02细胞的细胞核和胞质中的弥散分布,并使细胞内ADM的浓度由4.9 Oμg/ml提高至15.4μg/ml.RT-PCR结果显示K562/A02细胞mdr1 mRNA水平明显高于K562细胞,CA处理后K562/A02细胞mdr1 mRNA水平明显降低(P<0.01).流式细胞术检测K562/A02细胞膜上P-gp的荧光强度在经CA处理后由44.40降至22.80(P<0.05).Western blot结果显示CA处理后的K562/A02细胞膜上P-gp的表达明显降低.结论 在体外,CA可有效逆转人白血病细胞K562/A02的MDR,其逆转耐药的机制可能与P-gp蛋白表达下调并抑制其功能有关.     

鼠尾草酸逆转K562/A02细胞多药耐药的机制研究

Objective To investigate the effects of carnosic acid(CA)on reversal of the muhidrug resistance(MDR)of human leukemia cell line K562/A02 and its mechanism.Methods MTT assay was used to determine the sensitivity of K562/A02 cells to adriamycin(ADM)pre-and post-treated with CA.Flow cytometry(FCM)and laser scanning confocal microscopy(LSCM)were used to measure intracellular fluorescence intensity and concentration of ADM respectively.The expression level of mdr1 was detected by semi-quantitative RT-PCR.P-glycoprotein(P-gp)expression was detected by FCM and Western blot.Resuits CA decreased,IC50 of ADM in K562/A02 cells from 16.31 μg/mL to 1.35μg/mL,being a 12.08fold decrease.The intracellular ADM fluorescence intensity of K562/A02 was increased from 17.05 t0 60.53after treated with CA(P<0.01).In living K562/A02 ceils,after treated with CA,the diffuse distribution of intracellular ADM was recovered in both nuclear and cytoplasm,and the concentration of intracellular ADM increased from 4.93μg/mL to 15.43μg/mL.RT-PCR assay showed that CA inhibited the expressions of mdr1 mRNA in K562/A02 cells(P<0.01).Mean fluorescence intensity of P-gp detected by FCM in CA-treated K562/A02 was decreased to 22.80 as compared with that in untreated K562/A02 cells(44.40,P<0.05).Conclusion CA can reverse the MDR of K562/A02 cells in vitro.The mechanism may be associated with down-regulation of mdr1 and inhibition of P-gp function.     

鼠尾草酸逆转K562/A02细胞多药耐药的机制研究

Objective To investigate the effects of carnosic acid(CA)on reversal of the muhidrug resistance(MDR)of human leukemia cell line K562/A02 and its mechanism.Methods MTT assay was used to determine the sensitivity of K562/A02 cells to adriamycin(ADM)pre-and post-treated with CA.Flow cytometry(FCM)and laser scanning confocal microscopy(LSCM)were used to measure intracellular fluorescence intensity and concentration of ADM respectively.The expression level of mdr1 was detected by semi-quantitative RT-PCR.P-glycoprotein(P-gp)expression was detected by FCM and Western blot.Resuits CA decreased,IC50 of ADM in K562/A02 cells from 16.31 μg/mL to 1.35μg/mL,being a 12.08fold decrease.The intracellular ADM fluorescence intensity of K562/A02 was increased from 17.05 t0 60.53after treated with CA(P<0.01).In living K562/A02 ceils,after treated with CA,the diffuse distribution of intracellular ADM was recovered in both nuclear and cytoplasm,and the concentration of intracellular ADM increased from 4.93μg/mL to 15.43μg/mL.RT-PCR assay showed that CA inhibited the expressions of mdr1 mRNA in K562/A02 cells(P<0.01).Mean fluorescence intensity of P-gp detected by FCM in CA-treated K562/A02 was decreased to 22.80 as compared with that in untreated K562/A02 cells(44.40,P<0.05).Conclusion CA can reverse the MDR of K562/A02 cells in vitro.The mechanism may be associated with down-regulation of mdr1 and inhibition of P-gp function.     

三氧化二砷对K562及其多药耐药细胞系K562/A02细胞的诱导凋亡研究

Ｐ170表达阳性的白血病细胞往往对多种不同化学结构和作用靶点的药物同时发生耐药。我们观察了三氧化二砷(Ａｓ2 Ｏ3 )对体外培养的人急性红白血病细胞系Ｋ5 6 2及其多药耐药细胞系Ｋ5 6 2 /Ａ0 2细胞的凋亡诱导作用 ,以探讨Ａｓ2 Ｏ3 对多药耐药白血病细胞的作用。材料和方法1　药品　Ａｓ2 Ｏ3 (Ｓｉｇｍａ公司 )溶于Ｈａｎｋｓ缓冲液中 ,配制成 1ｍｍｏｌ/Ｌ ,保存于 4℃。2　细胞株及细胞培养　Ｋ5 6 2及其多药耐药细胞系Ｋ5 6 2 /Ａ0 2细胞 (中国医学科学院、中国协和医科大学血液学研究所提供 )置于含体积分数为 10 %小牛血清的ＲＰＭ…     

姜黄素、红霉素逆转K562/A02细胞多药耐药机制的研究

目的研究姜黄素（curcumin，Cur）及红霉素（erythromycin，EM）对多药耐药（MDR）细胞株K562／A02的影响及作用机制。方法MTF法测定Cur、EM作用后K562／A02细胞对阿霉素（ADM）敏感性的变化。流式细胞仪测定细胞内柔红霉素的平均荧光强度（DNR MFI）。免疫组化法检测细胞膜上P—gP的表达。RT—PCR法检测细胞mdr1 mRNA水平：结果Cur、EM均可减低ADM对K562／A02细胞的IC50值，两药合用时逆转倍数可达11．3倍。K562／A02细胞内DNR MFI明显低于K562细胞（P〈0．01），Cur、EM均可明显增加K562／A02细胞内DNR MFI（P〈0．05），以两药合用时作用最为明显，Cur2．5μg／ml处理组细胞内DNR MFI略高于EM120μg／ml处理组，但差异无统计学意义（P〉0．05）。免疫组化检测结果显示K562／A02细胞P—gP表达明显高于K562细胞（P〈0．01），各组药物分别处理后，K562／A02细胞膜P—gP表达减低（P〈0．01），但仍高于K562细胞（P〈0．01）；各药物组处理5d细胞膜P—gP表达均低于3d组（P〈0．01），Cur与EM合用时细胞膜P—gP表达降低最为明湿，低于其它处理组（P〈0．01）。RT—PCR结果显示K562／A02细胞mdr1 mRNA水平明显高于K562细胞（P〈0．01），各组药物处理后，K562／A02细胞mdr1 mRNA水平均减低（P〈0．01），5d组低于3d组，但仍高于K562细胞（P〈0．01）；Cur与EM合用时K562／A02细胞mdr1 mRNA水平降低最为显著，Cur 2．5μg／ml处理5dK562／A02细胞mdr1 mRNA水平低于EM120μg／ml处理5d组（P〈0．01）。结论Cur、EM均可部分逆转K562／A02细胞的MDR，降低其P—gP的表达和功能，逆转作用有时间依赖性；两药联合应用时逆转作用明湿增强，Cur2．5μg／ml逆转作用略强于EM120μg／ml。     

低氧诱导因子-1α对B-ALL细胞长春新碱敏感性的影响及机制研究

目的:研究低氧条件下急性B淋巴细胞白血病(B-ALL)细胞对长春新碱(VCR)敏感性的影响及可能的作用机制。方法:以B-ALL细胞SUP-B15、Nalm-6及RS4;11为研究对象,将细胞分为对照和低氧模拟组(CoCl₂预处理),两组细胞分别给予浓度递增的VCR处理24 h,采用CCK-8法检测细胞活性,流式细胞术检测细胞凋亡,蛋白免疫印迹法检测细胞内低氧诱导因子-1α(HIF-1α)、BAX、Bcl-2及β-Actin蛋白的表达水平,实时荧光定量PCR技术检测细胞内BAX及β-actin mRNA表达水平。结果:CoCl₂可模拟低氧环境诱导HIF-1α蛋白表达,SUP-B15及RS4;11低氧模拟组细胞对VCR的敏感性低于对照组;80 nmol/L VCR处理后低氧模拟组细胞的凋亡率低于对照组(P<0.05);低氧模拟组细胞的BAX mRNA及蛋白表达水平均低于对照组(P<0.05),Bcl-2蛋白表达水平在两组细胞间均未见明显变化。结论:低氧条件下HIF-1α可能通过下调促凋亡蛋白BAX表达导致B-ALL细胞对VCR耐药。     

低氧诱导因子-1α在血液系统恶性肿瘤中的研究进展

低氧诱导因子1-α(Hypoxia inducible factor,HIF-1α)为低氧环境下诱导产生的转录因子,调控低氧相关基因转录,是细胞特别是肿瘤细胞适应低氧环境生存的重要转录因子.HIF-1α在乳腺癌、肝癌等实体肿瘤中研究较多,HIF-1α表达水平增高与肿瘤的血管生成、转移、化疗耐药相关.近年来研究发现HIF...     

以K562/MDR细胞为模型的白血病多药耐药逆转研究

白血病细胞多药耐药（ＭＤＲ）是导致化疗失败的主要原因,其中ｍｄｒ１基因产物Ｐ糖蛋白（Ｐｇｐ）起着重要作用。多种Ｐｇｐ拮抗剂可逆转ＭＤＲ从而改善化疗结果。目前ＭＤＲ逆转研究多以药物加压筛选的耐药变异株为模型,但除其表达ｍｄｒ１基因外,尚有多种与耐...     

siRNA逆转K562/A02细胞多药耐药的研究

目的　研究小分子干扰RNA片段 (smallinterferingRNAs,siRNA)对白血病多药耐药细胞系K5 6 2 A0 2mdr1基因和P 糖蛋白 (P gp)表达及功能的影响。方法　根据mdr1基因已知序列设计 3条含 2 1个碱基的siRNA(si mdr1 1,si mdr1 2 ,si mdr1 3)及阴性对照 (si neg) ,在脂质体的介导下转染K5 6 2 A0 2细胞 ;用RT PCR分析mdr1mRNA的表达 ;流式细胞术检测P gp表达和细胞内柔红霉素积累量 ;MTT法检测阿霉素对K5 6 2 A0 2细胞的半数抑制浓度 (IC50 )。结果　 3条siRNA均能不同程度地逆转K5 6 2 A0 2细胞的多药耐药。第 3条序列能更有效地封闭mdr1基因 ,使mdr1mRNA相对水平下降(5 8.0± 1 5 4 ) % ;P gp表达由处理前的 (76 .0± 1.0 ) %降到处理后的 (19.6± 1.9) % ;对阿霉素药物敏感性的相对逆转效率为 70 .4 % ;同时使K5 6 2 A0 2细胞内柔红霉素积累量增加。结论　siRNA可逆转mdr1基因编码蛋白P gp介导的多药耐药。     

环孢菌素A、雷洛昔芬及其联合应用逆转K562/A02细胞多药耐药的研究

本研究探讨环孢菌素A（CsA）、雌激素受体抑制荆雷洛昔芬及其联合应用对K562／A02细胞多药耐药的逆转作用。采用甲基四唑蓝法（MTT）测定柔红霉素（DNR）的半数抑制量，RT-PCR法检测mdr1基因mRNA表达水平，FCM检测P-gp的表达和细胞内DNR浓度。结果表明：DNR对K562／A02和K562细胞的IC50分别为23．51和0．29mg／L，雷洛昔芬（2．5mg／L）及CsA（1mg／L）单用和两药联合处理K562／A02细胞时，DNR的IC50值分别为5．98、8．15和3．68mg／L，两药对DNR作用K562细胞的IC50没有影响。CsA及雷洛昔芬单独作用后耐药株mdr1mRNA下调微弱，联合用药下调效果明显。CsA及雷洛昔芬均可降低P-gP蛋白的表达，且具有协同作用。同时还观察到逆转剂雷洛昔芬和CsA作用后细胞内柔红霉素浓度增加，两药联合作用时效果增强。结论：CsA及雷洛昔芬均可逆转耐药。且联合作用效果增强。     

miR-451在白血病细胞株K562/A02多药耐药中的作用及相关机制

目的：检测miR-451、ABCB1、ABCC2在白血病药物敏感细胞株K562及其耐药株K562/A02中的差异表达,探讨miR-451与ABCB1、ABCC2表达的调控关系及miR-451参与白血病耐药的相关机制。方法：CCK-8法检测K562/A02及K562细胞的耐药性,实时荧光定量PCR(qRT-PCR)验证miR-451在K562及K562/A02细胞中的差异表达,将miR-451模拟物(mimic)及其阴性对照(miR-NC)、miR-451抑制剂(inhibitor)及其阴性对照(miR-inNC)分别转染K562及K562/A02细胞,应用q RT-PCR、Western blot检测ABCB1、ABCC2在K562、K562/A02细胞及转染后各组细胞中的mRNA、蛋白表达水平。结果：K562/A02细胞对阿霉素的耐药是其亲本细胞系K562的177倍。与K562细胞相比,K562/A02细胞中miR-451明显高表达(P<0.001),ABCB1、ABCC2在K562/A02中的mRNA及蛋白表达水平均显著高于K562细胞(P<0.001)。K562/A0...     

低氧诱导因子抑制剂对白血病细胞株HIF-1α和VEGF表达及诱导细胞凋亡作用的研究

本研究探讨低氧诱导因子抑制剂3-(5′-hydroxymethyl-2′-furyl)-1-benzylindazole(YC-1)对人急性白血病病细胞低氧诱导因子1α(hypoxia inducible factor1α,HIF-1α)和血管内皮因子(vascular endothelial growth factor,VEGF)的调节及诱导细胞凋亡作用。应用DAPI染色检查凋亡细胞的形态;流式细胞术检测细胞凋亡率;RT-PCR检测K562、U937、Jurkat白血病细胞株hif-1α和vegf mRNA表达以及YC-1对U937细胞hif-1α、vegf mRNA表达影响;Western blot检测YC-1对U937细胞HIF-1α和VEGF蛋白表达,以及BAX、BCL-2、caspase-3蛋白变化,分析YC-1诱导U937细胞凋亡的可能机制。结果表明:在3种白血病细胞株均可见hif-1α和vegf mRNA表达。4μmol/L YC-1处理U937细胞(0、8、16和24小时)后,可见凋亡细胞出现的典型凋亡形态特征;流式细胞术检测的细胞0、8、16和24小时凋亡率分别为(4.87±0.70)%、(27.27±2.00)%、(51.53±2.81)%及(60.5±3.20)%;vegf mRNA表达下调,而hif-1αmRNA表达无明显变化;HIF-1α蛋白、VEGF蛋白和BCL-2蛋白表达下调,而BAX和caspase-3蛋白表达上调,BAX/BCL-2比率升高并呈时间依赖性(r=0.973,p0.01)。结论:3种白血病细胞株均显示hif-1α和vegf mRNA表达,YC-1可以抑制白血病细胞HIF-1α蛋白表达,进而下调VEGF,并通过上调BAX/BCL-2比率、caspase-3蛋白表达诱导细胞凋亡。     

环孢菌素D衍生物PSC 833逆转K562/A02细胞多药耐药的研究

目的 证实PSC833逆转剂的高效性，探讨PSC833逆转肿瘤细胞多药耐药的机制。方法 以人红白血病细胞系K562及其耐药细胞系K562／A02（耐阿霉素）为实验研究对象，采用MTT法检测细胞毒性；直接免疫荧光测定法检测P糖蛋白（P-gp）表达水平；RT－PCR法检测mdr1 mRNA水平，以流式细胞术测定两种细胞系内柔红霉素（DNR）的潴留来的反映P-gp的外排功能。结果 与K562细胞系相比，K562／A02耐药细胞系mdr1 mRNA及P－gp高表达，DNR潴留减少。1μmol/L的PSC833对K562／A02铁mdr1 mRNA及P－gp表达水平无明显影响（P＞0.05），PSC833对K562／A02细胞的DNR细胞毒性有剂量依赖性增敏作用，其增敏作用至少是环孢菌素A（CsA）、维拉帕米（Ver）的3倍。PSC833能增加K562／A02耐药细胞系的DNR潴留。1μmol/L的PSC833能使K562／A02细胞内DNR潴留量恢复至K562细胞的100.9%，而10μmol/L CsA只恢复至K562细胞的86.9%，PSC833对K562细胞系的DNR细胞毒性及DNR潴留均无明显影响（P＞0.05）。结论 PSC833较CsA、Ver逆转活性至少高3－10倍，其逆转K562／A02多药耐药的机制可能是通过抑制P－gp功能，而非直接下调mdr1 mRNA及P-gp水平。     

低氧对大鼠肝肾组织内红细胞生成素和低氧诱导因子-1α基因表达的影响

目的　观察急性低氧和间断低氧习服对大鼠肝、肾组织内红细胞生成素 (EPO)及其调控蛋白低氧诱导因子 1α(HIF 1α)基因表达的影响。方法　用低压舱模拟高原低氧环境 ,进行 30 0 0 m 2周、5 0 0 0 m2周低氧训练 ,使大鼠达到低氧习服状态后 ,采用 Northern斑点杂交研究间断低氧习服前后 ,80 0 0 m4 h低氧处理的大鼠肝、肾组织内 EPO和 HIF 1α基因表达的变化。结果　与常氧对照组相比 ,急性低氧处理的大鼠肝、肾组织内 EPO基因表达都明显增强 (P<0 .0 5或 P<0 .0 1) ;而间断低氧习服后 ,同样的低氧处理的大鼠肝、肾组织中 EPO基因表达都明显低于急性低氧组 (P<0 .0 1) ,EPO m RNA含量与常氧对照组水平差异不显著 (P>0 .0 5 )。急性低氧处理的大鼠肝组织中 HIF 1α基因表达水平明显高于常氧对照组和间断低氧习服组 (P均 <0 .0 1) ,而在不同处理的肾组织中 ,该基因表达水平差异不明显 (P均 >0 .0 5 )。结论　急性低氧能够刺激肝、肾组织内 EPO基因表达 ;而间断低氧习服的大鼠耐低氧能力明显增强 ,肝、肾组织内 EPO基因表达水平可恢复到常氧对照组水平。 HIF 1α在低氧影响 EPO基因表达的过程中可能起着重要的调节作用。     

低氧诱导因子-1α在大鼠心肌梗死中的表达及其意义

目的：观察低氧诱导因子-1α（HIF1α）在梗死心肌中mRNA表达水平的变化。方法：结扎SD大鼠冠状动脉左前降支制备心肌梗死模型。36只大鼠随机分为对照组（6只）和模型组（30只），模型组于冠状动脉结扎后24h、48～72h和1周时分别取左心室心肌梗死区及非梗死区组织．用半定量逆转录-聚合酶链反应（RT—PCR）检测HIF—1α mRNA的表达。结果：模型组不同时间点HIF-1α在梗死区心肌中mRNA表达水平均明显升高，且与非梗死区心肌比较差异均有显著性（P均〈0．01），在缺血l周内持续在高水平，模型组非梗死区域心肌组织与对照组HIF-1α mRNA水平比较差异无显著性（P均〉0．05）。结论：HIF1α mRNA在心肌梗死区的高表达是心肌对缺血和缺氧导致心肌坏死的一种分子水平的反应。     

甲基莲心碱、红霉素逆转K562／A02细胞多药耐药及其机制的研究

多药耐药(muhidrug resistance，MDR)足当今肿瘤治疗的一大难点，中药复方拈新康有逆转耐药，增加化疗效果的作用，其有效成分甲基莲心碱(Nef)可增加肿瘤细胞内抗癌药物浓度逆转MDR大环内酯类抗生素红霉素(EM)体外有逆转MDR的作用。为探讨Nef、EM逆转白血病细胞MDR的机制，我们以多药耐药细胞株K562／A02为研究对象，分别采用MTT法，免疫组化SABC法，RT-PCR法研究Nef、EM对K562／A02细胞增殖及PgP／mdrl基因表达的影响。     

低氧诱导因子-1α对肺癌生长影响的研究

目的:研究抑制低氧诱导因子-1α(HIF-1α)表达对肺癌细胞体内生长的影响并探讨可能机制。方法:以小RNA干扰(siRNA)表达质粒抑制A549肺癌细胞的HIF-1α表达,建立稳定表达细胞株并接种于裸鼠,观察肿瘤生长情况,TUNEL法检测细胞凋亡,MTT法检测细胞增殖。结果:抑制HIF-1α表达可加速肿瘤生长,促进细胞增殖并抑制细胞凋亡的发生,降低糖酵解关键基因的表达。结论:HIF-1α在低氧环境下可能通过上调糖酵解基因表达促进糖酵解,改变细胞生长环境,促进细胞凋亡并抑制细胞增殖。