背景:急性髓系白血病(AML),恶性肿瘤通常对普通化疗方案(阿糖胞苷(Ara-c)+柔红霉素(DNR))耐药,伴随着频繁的复发。许多因素参与引起化学抗性。血红素氧合酶-1(HO-1)和缺氧诱导因子-α(HIF-1α)是两个最著名的基因,据报道,在AML中过度表达,并促进对化疗的耐药性。用于AML治疗的主要化疗药物是Ara-c。我们假设同时靶向HO-1和HIF-1α可以使AML细胞对Ara-c敏感。
方法:在本研究中,我们用我们最近开发的,反式转录激活剂(TAT)-壳聚糖-羧甲基葡聚糖(CCMD)-聚乙二醇(PEG)-纳米颗粒(NP),将Ara-c与针对HO-1和HIF-1α基因的siRNA分子一起递送至AML原代细胞(离体)和包括THP-1、KG-1和HL-60的细胞系(体外)。随后,单一或组合处理对生长的影响,扩散,凋亡,并评估了活性氧(ROS)的形成。
结果:设计的NP在用siRNA和药物转染细胞方面具有很高的潜力。结果表明,用Ara-c处理细胞提高了细胞中ROS的产生,同时降低了增殖潜能。HO-1沉默后,响应Ara-c的凋亡率和ROS产生率显着增加。而与用游离Ara-c处理的细胞相比,HIF-1α-siRNA转染的AML细胞中的增殖和生长抑制是相当明显的。我们发现基因的共同抑制可以进一步使AML细胞对Ara-c治疗敏感。
结论:据我们所知,这项研究是首次使用NP同时抑制AML中的HO-1和HIF-1α基因。可以得出结论,HO-1通过保护细胞免受ROS损伤而引起化学抗性。然而,HIF-1α主要发挥大量和直接的抗凋亡作用。这些发现表明,同时抑制HO-1和HIF-1α可以克服Ara-c抵抗,并有助于改善AML患者的预后。
BACKGROUND: Acute myeloid leukemia (
AML), a malignancy Often resistant to common chemotherapy regimens (Cytarabine (Ara-c) + Daunorubicin (DNR)), is accompanied by frequent relapses. Many factors are involved in causing chemoresistance. Heme Oxygenase-1 (HO-1) and Hypoxia-Inducible Factor 1-alpha (HIF-1α) are two of the most well-known genes, reported to be overexpressed in AML and promote resistance against chemotherapy according to several studies. The main chemotherapy agent used for
AML treatment is Ara-c. We hypothesized that simultaneous targeting of HO-1 and HIF-1α could sensitize
AML cells to Ara-c.
METHODS: In this study, we used our recently developed, Trans-Activator of Transcription (TAT) - Chitosan-Carboxymethyl Dextran (CCMD) - Poly Ethylene Glycol (PEG) - Nanoparticles (NPs), to deliver Ara-c along with siRNA molecules against the HO-1 and HIF-1α genes to
AML primary cells (ex vivo) and cell lines including THP-1, KG-1, and HL-60 (in vitro). Subsequently, the effect of the single or combinational treatment on the growth, proliferation, apoptosis, and Reactive Oxygen Species (ROS) formation was evaluated.
RESULTS: The designed NPs had a high potential in transfecting cells with siRNAs and drug. The results demonstrated that treatment of cells with Ara-c elevated the generation of ROS in the cells while decreasing the proliferation potential. Following the silencing of HO-1, the rate of apoptosis and ROS generation in response to Ara-c increased significantly. While proliferation and growth inhibition were considerably evident in HIF-1α-siRNA-transfected-AML cells compared to cells treated with free Ara-c. We found that the co-inhibition of genes could further sensitize
AML cells to Ara-c treatment.
CONCLUSIONS: As far as we are aware, this study is the first to simultaneously inhibit the HO-1 and HIF-1α genes in AML using NPs. It can be concluded that HO-1 causes chemoresistance by protecting cells from ROS damage. Whereas, HIF-1α mostly exerts prolific and direct anti-apoptotic effects. These findings imply that simultaneous inhibition of HO-1 and HIF-1α can overcome Ara-c resistance and help improve the prognosis of AML patients.