Chen Si-yu, Ma Li-heng, Dong Ying, Guo Wei-jian, Wang Zhen-yi
Department of Oncology, Xinhua Hospital, Shanghai Jiaotong University, Shanghai 200092, China.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi. 2007 Sep;23(9):824-6.
To investigate effects of arsenic trioxide (As(2)O(3)) and alltrans retinoic acid (ATRA) on PLZF-RARalpha-positive cells.
PLZF-RARalpha-positive U937 cells (U937/PLZF) were used as an in vitro model. The change of cell morphology was observed by Wright-Giemsa staining. Cell growth and proliferation were detected by methyl thiazolyl tetrazolium(MTT) assay. Cell cycle distribution and expression of cell membrane surface differentiation-related antigens (such as CD11b, CD64 and CD14) were determined by flow cytometry assay. Expression of PLZF was analyzed by immunofluorescence. Functional differentiation was reflected by nitroblue tetrazolium(NBT) reduction ability and cytochemistry staining.
While U937/PLZF cells were incubated in tetracycline-withdrawn medium, the expression of PLZF-RARalpha; protein increased. After treated with As(2)O(3) (0.5 micromol/L) and ATRA (1 mumol/L), U937/PLZF cells presented some changes such as decreased nuclear/cytoplasm ratio, and partial disappearance of nucleoli, suggesting a certain degree of morphological differentiation. The cell growth and proliferation were inhibited in a dose- and time-dependent manner. The proportion of cells in S phage was decreased and CD11b level was increased. The expression of PLZF relocated in treated cells. However, no significant difference in NBT assay and cytochemistry staining was documented with the combination therapy.
The combination of As(2)O(3) with ATRA can cause a slight tendency to morphological differentiation but is insufficient to induce functional differentiation of PLZF-RARalpha positive U937 leukemia cells.
研究三氧化二砷（As₂O₃）和全反式维甲酸（ATRA）对PLZF-RARα阳性细胞的影响。
以PLZF-RARα阳性的U937细胞（U937/PLZF）作为体外模型。通过瑞氏-吉姆萨染色观察细胞形态变化。采用甲基噻唑基四氮唑（MTT）法检测细胞生长和增殖情况。通过流式细胞术检测细胞周期分布及细胞膜表面分化相关抗原（如CD11b、CD64和CD14）的表达。通过免疫荧光分析PLZF的表达。用硝基蓝四氮唑（NBT）还原能力和细胞化学染色反映功能分化情况。
当U937/PLZF细胞在不含四环素的培养基中培养时，PLZF-RARα蛋白表达增加。用As₂O₃（0.5 μmol/L）和ATRA（1 μmol/L）处理后，U937/PLZF细胞出现一些变化，如核质比降低、核仁部分消失，提示有一定程度的形态分化。细胞生长和增殖受到剂量和时间依赖性抑制。S期细胞比例降低，CD11b水平升高。处理后细胞中PLZF的表达发生重新定位。然而，联合治疗在NBT试验和细胞化学染色方面无显著差异。
As₂O₃与ATRA联合应用可使PLZF-RARα阳性U937白血病细胞有轻微的形态分化倾向，但不足以诱导其功能分化。
