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.     

成人B细胞性急性淋巴细胞白血病RAG1表达特点及临床意义

目的:探讨成人B细胞性急性淋巴细胞白血病(B-ALL)中RAG1基因的表达特点及其临床意义。方法:应用实时定量PCR方法检测104例初发、22例复发成人B-ALL患者和30例正常对照者RAG1基因的表达,分析基因表达特点及其与临床和实验室参数之间的关系。结果:初发、复发成人B-ALL患者RAG1基因表达水平均高于正常对照者(3.94 vs 1.23)(P0.001);(5.86 vs1.23)(P0.01)。6例初发与复发患者成对标本分析显示,RAG1表达水平在疾病复发时显著高于初发(13.65 vs2.31)(P0.01)。IKZF1基因外显子3-6缺失的异构体Ikaros isoform 6(Ik6)阳性患者RAG1基因表达水平显著高于Ik6阴性患者(5.30 vs2.11)(P0.05)。RAG1高表达组LDH水平大于1 000 U/L患者的比例显著高于低表达组(42.2%vs20.5%)(P0.05)。结论:RAG1基因表达上调在成人B-ALL发生发展中尤其在复发过程中可能起重要作用,其上调与IKZF1基因缺失相关。监测RAG1表达水平的变化可能为临床预测成人B-ALL患者疾病进展提供帮助。     

甲基化特异性微阵列法定量检测恶性血液病患者p16基因甲基化

DNA甲基化是细胞的一种表观遗传现象,也是一种重要的影响基因表达的机制.当DNA异常甲基化时会导致癌基因的激活和抑癌基因的沉默,促使肿瘤的发生[1].     

MTT比色法的改良及其在LAK细胞活性检测中的应用

目的：改良四甲基偶氮唑盐（MTT）比色法,并用来检测淋巴因子激化的杀伤细胞（LAK细胞）活性。方法：在MTT代谢产物甲瓒DMSO溶解后的最佳吸光度测定及效靶细胞不同孵育时间的比较等方面进行研究。结果：MTT代谢产物甲瓒DMSO溶解后的最佳吸光度为510nm,效靶细胞最佳孵育时间为4h。结论：改良的MTT比色法优于常规的MTT比色法。     

C3435T多态性与肿瘤发病风险及疗效的关系

多药耐药基因1(MDR1)C3435T多态性影响肿瘤发病风险及疗效.由于T等位基因能够使致癌物质更易在组织中积聚,因此TT基因型患者更易发生乳腺癌、胃癌、结直肠癌.并且C3435TTT基因型与KRAS基因野生型同时存在的患者化疗效果最好.但由于种族不同、地区差异、样本量不同等客观因素存在,C3435T多态性与乳腺癌、胃...     

脾切除治疗移植相关血栓性微血管病导致血小板减少一例报告附文献复习

移植相关血栓性微血管病(TA-TMA)是指发生于造血干细胞移植(HSCT)后,以微血管病性溶血性贫血、消耗性血小板减少以及脏器功能不全为特征,包括血栓性血小板减少性紫癜和溶血尿毒症综合征在内的一组疾病的总称,首次报道于1980年[1].TA-TMA起病急骤,多发于HSCT后120 d内,早期死亡率极高,具体发病机制不明,主要与内皮细胞功能失调有关.我们采用脾切除术治疗1例重型再生障碍性贫血(SAA)移植后TA-TMA导致血小板减少患者,报道如下,并进行相关文献复习.     

藤黄酸对SKM-1细胞生长抑制作用及其机制

本研究探讨藤黄酸（GA）对骨髓增生异常综合征细胞SKM-1生长抑制和诱导细胞凋亡及其机制。采用MTr比色法检测GA对SKM-1细胞的增殖抑制作用,在光学显微镜下观察细胞形态学变化,流式细胞术检测细胞凋亡和细胞周期分布,RT-PCR检测SKM-1细胞baxmRNA和bcl-2mRNA表达情况。结果表明：GA能明显抑制SKM-1细胞增殖,具有时间和剂量依赖性,其48h的IC50值为0．37μg/ml;GA诱导SKM-1细胞凋亡,具有浓度依赖性,诱导SKM-l阻滞在G0／G1期;显微镜下可见典型的凋亡细胞形态特征;GA可明显下调SKM-1细胞bcl-2mRNA表达和上调baxmRNA表达。结论：GA能诱导SKM-1细胞凋亡,其机制可能与细胞G0／G1期阻滞及bcl-2／bax比率下调有关。     

BCR/ABL探针在骨髓增殖性疾病中的临床运用

本研究通过回顾分析荧光原位杂交(FISH)检测BCR/ABL融合基因结果,探讨其在慢性骨髓增殖性疾病(CMPD)和Ph+急性淋巴细胞白血病(Ph+ALL)的鉴别诊断及治疗后微小残留病(MRD)动态监测中的运用价值。初诊和治疗后病例分别使用BCR/ABL(ES)和BCR/ABL(DF)探针检测BCR/ABL融合基因。结果表明:初诊CMPD 49例,形态学符合CML骨髓象28例,确诊CML 23例,形态符合率23/28(82.1%),BCR/ABL阳性23/23,敏感度、特异度均为100%。确诊病例BCR/ABL阳性细胞率为81.3%±17.7%;allo-HSCT 13例,9例长期无病生存,4例复发,经供者淋巴细胞输注(DLI)、伊马替尼或allo-HSCT治疗后多次监测BCR/ABL阴性;伊马替尼治疗16例,其中11例于1年后多次监测BCR/ABL阴性,5例分别于6、7、10年后监测BCR/ABL阳性,其中1例经allo-HSCT成功,BCR/ABL转阴。结论:FISH技术是一项敏感、特异的诊断技术,针对初诊和治疗后病例分别运用两种不同的探针检测BCR/ABL融合基因,有助于准确、快速鉴别诊断CML、Ph+ALL,动态监测酪氨酸激酶抑制剂治疗和allo-HSCT后MRD。