Docosahexaenoic acid modulates different genes in cell cycle and apoptosis to control growth of human leukemia HL-60 cells.
Docosahexaenoic acid modulates different genes in cell cycle and apoptosis to control growth of human leukemia HL-60 cells.
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DOI：
10.3892/ijo.25.3.737
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发表时间：
2004-09
影响因子：
5.2
通讯作者：
L. C. Chiu;E. Wong;V. Ooi
中科院分区：
文献类型：
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作者：
L. C. Chiu;E. Wong;V. Ooi
虽然以前的研究表明，鱼油中的二十二碳六烯酸（DHA; 22：6 omega 3）抑制不同癌症的生长，但这些油中毒素污染的安全问题一再提出。最近有人建议将培养的微藻作为一种更清洁、更安全的脂肪酸来源。本研究探讨了从富集的柯氏隐甲藻（Crypthecodiniumcohnii，ADHA）中提取的DHA对人白血病HL-60细胞生长的调控作用及其机制。与10-160 μ M脂肪酸孵育72小时后，ADHA剂量依赖性地延迟白血病细胞增殖，为对照水平的4-93%; 50%抑制浓度（IC 50）估计为74 μ M。DNA流式细胞仪检测结果显示，ADHA与IC 50作用24、48和72 h后，G 0/G1期细胞的阻滞率为12-22%，诱导凋亡率为569-906%。进一步阐明了ADHA的细胞周期阻滞和促凋亡作用模式。基因芯片分析表明，ADHA调制的细胞周期和凋亡基因的数量来控制细胞生长，特别是，脂肪酸上调转录抑制因子E2 F-6和促凋亡Bax的1435和4172%，分别孵育24小时后。半定量RT-PCR研究进一步显示ADHA诱导Bax mRNA转录水平升高，并呈时间依赖性。同时，ADHA还可诱导白血病细胞中Rb蛋白磷酸化，从而使Rb蛋白失活。以上结果提示ADHA通过上调Bax蛋白表达和抑制Rb蛋白表达，诱导HL-60细胞生长调控和凋亡。
Although previous studies have shown that docosahexaenoic acid (DHA; 22:6 omega 3) from fish oils inhibits growth of different cancers, safety issues have been raised repeatedly about contaminations of toxins in these oils. Cultured microalgae are suggested recently as an alternative cleaner and safer source of the fatty acid. We investigated in this study the function of DHA from the enriched microalga Crypthecodinium cohnii (ADHA) in cell-growth control and its mechanism in human leukemia HL-60 cells. ADHA retarded proliferation of the leukemia cells dose-dependently by 4-93% of the control level, after 72-h incubations with 10-160 micro M of the fatty acid; and the 50% inhibitory concentration (IC50) was estimated as 74 micro M. DNA-flow cytometry study showed that ADHA arrested G0/G1 cells by 12-22% and induced apoptotic cells by 569-906% of their controls, after incubation with the IC50 of ADHA for 24, 48 and 72 h. The modes of cell-cycle arrest and pro-apoptotic actions of ADHA were further elucidated. Gene-array analysis illustrated that ADHA modulated a number of cell-cycle and apoptosis genes to control the cell growth; in particular, the fatty acid up-regulated the transcriptional repressor E2F-6 and pro-apoptotic Bax by 1435 and 4172% respectively, after 24 h of incubation. Semi-quantitative RT-PCR study further showed that ADHA induced elevation of the Bax mRNA transcript time-dependently. In meanwhile, ADHA also induced phosphorylation and thus inactivation of Rb protein in the leukemia cells. All these results suggest that ADHA up-regulates Bax and inactivates Rb protein to induce the cell-growth control and apoptosis in human leukemia HL-60 cells.