Department of Clinical Hematology, Key Laboratory of Laboratory Medical Diagnostics Designated by the Ministry of Education, Chongqing Medical University, Chongqing 400016, P.R. China.
Int J Oncol. 2010 Apr;36(4):899-904. doi: 10.3892/ijo_00000568.
Apg-2, a mammalian heat-shock protein belonging to the heat-shock protein 110 (Hsp110) family, was previously found to be overexpressed in BaF3-BCR/ABL cells that were treated with hydrogen peroxide (H2O2) through our comparative proteomics study. The expression of Apg-2 in chronic myelogenous leukemia (CML) cells and its role have not been investigated, forming the basis for this study. BaF3-MIGR1 and BaF3-BCR/ABL cell lines stably overexpressing Apg-2 were established and exposed to 50 microM H2O2 for 10 min. Western blot analysis of Apg-2 expression confirmed that H2O2 treatment significantly up-regulated Apg-2 expression. Apg-2 overexpression elevated BaF3-BCR/ABL cell proportions in S and G2/M phase, increased cell proliferation and colony formation in vitro. Moreover, BaF3-MIGR1 and BaF3-BCR/ABL cells were exposed to 50 microM H2O2 in the absence or presence of Apg-2 overexpression and induction of H2AX phosphorylation, the reporters of DNA damage were assessed by Western blot and immunofluorescence. Results showed that exposure to H2O2 induced H2AX phosphorylation in BaF3-MIGR1 cells, but no increase was observed in BaF3-BCR/ABL cells. Together, the data indicate that Apg-2 is overexpressed and overexpression of Apg-2 in BaF3-BCR/ABL cells increases cell proliferation and protects cells from oxidative damage, which may play an important role in CML carcinogenesis and progression.
APG-2，一种属于热休克蛋白 110（Hsp110）家族的哺乳动物热休克蛋白，先前在我们的比较蛋白质组学研究中发现，过氧化氢（H2O2）处理的 BaF3-BCR/ABL 细胞中过度表达。APG-2 在慢性髓性白血病（CML）细胞中的表达及其作用尚未被研究，这构成了本研究的基础。本研究构建了稳定过表达 Apg-2 的 BaF3-MIGR1 和 BaF3-BCR/ABL 细胞系，并暴露于 50μM H2O2 中 10 分钟。Western blot 分析 Apg-2 的表达证实，H2O2 处理显著上调 Apg-2 的表达。APG-2 的过表达使 BaF3-BCR/ABL 细胞在 S 和 G2/M 期的比例增加，体外细胞增殖和集落形成增加。此外，在不存在或存在 Apg-2 过表达的情况下，将 BaF3-MIGR1 和 BaF3-BCR/ABL 细胞暴露于 50μM H2O2 中，并通过 Western blot 和免疫荧光评估 DNA 损伤的报告物 H2AX 磷酸化。结果表明，H2O2 暴露诱导了 BaF3-MIGR1 细胞中的 H2AX 磷酸化，但在 BaF3-BCR/ABL 细胞中没有观察到增加。总之，这些数据表明 Apg-2 过度表达，并且 Apg-2 在 BaF3-BCR/ABL 细胞中的过表达增加了细胞增殖并保护细胞免受氧化损伤，这可能在 CML 的发生和进展中起重要作用。
