CAJ | 학술논문

不断增殖是肿瘤的基本特征.一些基本的细胞周期调控分子参与了肿瘤的形成.细胞周期蛋白A(cyclin A)是在G1/S期表达的细胞周期蛋白(cyclin),其异常高表达参与了肿瘤的形成.为了探讨cyclin A异常高表达与白血病细胞恶性增殖的关系,采用流式细胞仪胞浆内间接免疫荧光/DNA双染色法半定量分析了急性白血病患者、门诊修回骨髓穿刺的患者、健康献血者这三种不同来源的外周血或骨髓标本细胞,以及白血病细胞系(HL-60) cyclin A表达水平.为了进一步研究cyclin A在白血病细胞增殖中的作用,用在体内、体外均有抗肿瘤作用的六亚甲基二乙酰胺(HMBA)在体外抑制白血病细胞系HL-60增殖,并诱导其分化.增殖抑制效应采用四唑盐还原试验和细胞周期分析来检测.细胞表面分化抗原CD33、CD11b改变来检测分化.结果发现,两组来自白血病标本的细胞S期cyclin A (即急性白血病患者外周血或骨髓幼稚细胞和白血病细胞系)表达阳性率要远远高于另两组(门诊骨髓穿刺的患者骨髓细胞和健康献血员外周血细胞);在HMBA抗肿瘤细胞系HL-60增殖实验中发现随药物剂量的加大,增殖抑制和分化程度呈剂量依赖性;同时,胞内cyclin A蛋白表达水平被明显下调了,也呈剂量依赖性.结论:白血病细胞S期cyclin A异常高表达,HMBA能下调 S期cyclin A表达水平,且随着胞内S期cyclin A表达下调,细胞增殖被抑制和分化程度亦不断加深,两者均呈剂量依赖性,这证明了下调cyclin A表达是HMBA抗白血病细胞系增殖的主要机理,同时提示cyclin A的异常高表达参与了白血病恶性增殖的环节.
불단증식시종류적기본특정.일사기본적세포주기조공분자삼여료종류적형성.세포주기단백A(cyclin A)시재G1/S기표체적세포주기단백(cyclin),기이상고표체삼여료종류적형성.위료탐토cyclin A이상고표체여백혈병세포악성증식적관계,채용류식세포의포장내간접면역형광/DNA쌍염색법반정량분석료급성백혈병환자、문진수회골수천자적환자、건강헌혈자저삼충불동래원적외주혈혹골수표본세포,이급백혈병세포계(HL-60) cyclin A표체수평.위료진일보연구cyclin A재백혈병세포증식중적작용,용재체내、체외균유항종류작용적륙아갑기이을선알(HMBA)재체외억제백혈병세포계HL-60증식,병유도기분화.증식억제효응채용사서염환원시험화세포주기분석래검측.세포표면분화항원CD33、CD11b개변래검측분화.결과발현,량조래자백혈병표본적세포S기cyclin A (즉급성백혈병환자외주혈혹골수유치세포화백혈병세포계)표체양성솔요원원고우령량조(문진골수천자적환자골수세포화건강헌혈원외주혈세포);재HMBA항종류세포계HL-60증식실험중발현수약물제량적가대,증식억제화분화정도정제량의뢰성;동시,포내cyclin A단백표체수평피명현하조료,야정제량의뢰성.결론:백혈병세포S기cyclin A이상고표체,HMBA능하조 S기cyclin A표체수평,차수착포내S기cyclin A표체하조,세포증식피억제화분화정도역불단가심,량자균정제량의뢰성,저증명료하조cyclin A표체시HMBA항백혈병세포계증식적주요궤리,동시제시cyclin A적이상고표체삼여료백혈병악성증식적배절.
Uncontrolled cell proliferation is the basic feature of cancer. Some of the prime cell cycle regulators are involved directly in tumorigenesis. Cyclin A, one of the G1/S cyclin, can cause transformation. The purpose of this research was to investigate whether cyclin A overexpression was involved in leukemogenesis and proliferation of leukemia cells. The expression of cyclin A at S-phase in leukemia cell line HL-60, blast cells of acute leukemia patients, bone marrow cells of outpatients without malignant hematological disease and peripheral blood cells of healthy donors was investigated by simultaneous indirect immunofluorence staining of intracellular antigen and DNA. To further investigate whether cyclin A played as a key molecular in cell proliferation, HL-60 cells were exposed to different concentrations of hexamethylene bisacetamide (HMBA). MTT dye absorbance of living cells and cell cycle analysis were adopted to evaluate growth arrest. Differentiation was evaluated by detection of the change of expression of CD11b and CD33 on cell surface. The results showed that overexpression of cyclin A was only found among specimens from acute leukemia and leukemia cell line. There was no elevated cyclin A detection for cyclin A among specimens from outpatients and healthy donors. In HMBA interference experiment, HMBA was able to induce growth arrest and monocytic macrophase differentiation of HL-60 cells in a dose-dependent manner, and all these changes were associated with a marked down-regluation of cyclin A expression. In condlusion, aberrant overexpression of cyclin A at S-phase was only found in leukemia cell lines and blast cells from acute leukemia. The dose-dependent effect of HMBA on cell growth and differentiation of HL-60 cell line which was consistent with the decrease of cyclin A expression in these cells suggested that the molecular mechanisms of HMBA inducement involved downregulation of cyclin A expression.