Abstract

Odd-skipped related transcription factor 1 (OSR1) is implicated in various pathophysiologic processes, such as embryonic heart and urogenital formation, and functions as a tumour suppressor in diverse tumours. Regardless, the regulatory role and mechanism of OSR1 in acute myeloid leukaemia are scarce. Firstly, the CD34-positive blasts or the normal blasts were isolated from the plasma samples of acute myeloid leukaemia patients or healthy donors, respectively. Expression of OSR1 analysis by western blot and qRT-PCR showed that OSR1 was reduced in CD34-positive blasts and acute myeloid leukaemia cell lines. Secondly, acute myeloid leukaemia cell lines were transfected with pcDNA vector or shRNA for the over-expression or silence of OSR1, respectively. Functional assays demonstrated that ectopic expression of OSR1 decreased cell viability and repressed the proliferation of acute myeloid leukaemia cells, while promoted the cell apoptosis. Silence of OSR1 contributed to the proliferation of acute myeloid leukaemia cells and suppressed the cell apoptosis. Thirdly, over-expression of OSR1 decreased protein expression of leucine-rich-repeat-containing G-protein-coupled receptor 5 (LGR5) and JNK phosphorylation in the acute myeloid leukaemia cells. Ectopic expression of LGR5 attenuated OSR1 over-expression-induced decrease of LGR5 and JNK phosphorylation. Lastly, ectopic expression of LGR5 attenuated OSR1 over-expression-induced decrease of cell viability and proliferation in acute myeloid leukaemia cells. In conclusion, OSR1 functioned as a tumour suppressor in acute myeloid leukaemia cells by inhibiting LGR5-mediated activation of JNK signalling.

摘要

奇数跳跃相关转录因子 1 (OSR1) 与各种病理生理过程有关，例如胚胎心脏和泌尿生殖系统的形成，并在多种肿瘤中充当肿瘤抑制因子。无论如何，OSR1在急性髓系白血病中的调节作用和机制是稀缺的。首先，分别从急性髓性白血病患者或健康供体的血浆样品中分离出CD34阳性原始细胞或正常原始细胞。通过蛋白质印迹和 qRT-PCR 分析 OSR1 的表达显示 OSR1 在 CD34 阳性原始细胞和急性髓性白血病细胞系中降低。其次，用pcDNA载体或shRNA转染急性髓性白血病细胞系，分别过表达或沉默OSR1。功能测定表明，OSR1 的异位表达降低了细胞活力并抑制了急性髓性白血病细胞的增殖，同时促进了细胞凋亡。OSR1的沉默有助于急性髓性白血病细胞的增殖并抑制细胞凋亡。第三，OSR1 的过表达降低了急性髓细胞白血病细胞中富含亮氨酸重复序列的 G 蛋白偶联受体 5 (LGR5) 的蛋白质表达和 JNK 磷酸化。LGR5 的异位表达减弱了 OSR1 过表达诱导的 LGR5 和 JNK 磷酸化的降低。最后，LGR5 的异位表达减弱了 OSR1 过表达诱导的急性髓性白血病细胞中细胞活力和增殖的降低。综上所述，