腺苷脱氨酶作用于RNA1(ADAR1),一种RNA编辑酶,通过双链RNA的脱氨基作用将腺苷转化为肌苷,在各类癌症的发生和发展中起着重要作用。近年来,Ferroptosis已成为癌症研究的热门话题。我们先前报道过ADAR1通过调节miR-335-5p和METTL3促进乳腺癌进展。然而,ADAR1是否对乳腺癌细胞的铁凋亡有影响尚不清楚.在这项研究中,我们使用CRISPR-Cas9技术敲低ADAR1或使用表达ADAR1的质粒在MCF-7和MDA-MB-231乳腺癌细胞系中过表达ADAR1蛋白,然后检测细胞活力,和ROS的水平,MDA,GSH,Fe2+,GPX4蛋白和miR-335-5p。我们发现细胞增殖受到抑制,ROS的水平,MDA,Fe2+,和miR-335-5p增加,与对照组相比,ADAR1丢失后GSH和GPX4水平降低。在细胞中ADAR1过表达后观察到相反的作用。Further,我们证明了ADAR1控制的miR-335-5p靶向GPX4的Sp1转录因子,这是一种已知的铁死亡分子标记,导致乳腺癌细胞中ADAR1抑制铁凋亡。此外,ADAR1的RNA编辑活性对于诱导铁死亡不是必需的。总的来说,ADAR1缺失通过调节miR-335-5p/Sp1/GPX4途径诱导乳腺癌细胞铁凋亡。这些发现可能为ADAR1通过抑制铁性凋亡促进乳腺癌进展的机制提供了见解。
Adenosine deaminases acting on RNA 1(
ADAR1), an RNA editing enzyme that converts adenosine to inosine by deamination in double-stranded RNAs, plays an important role in occurrence and progression of various types of cancer. Ferroptosis has emerged as a hot topic of cancer research in recent years. We have previously reported that ADAR1 promotes breast cancer progression by regulating miR-335-5p and METTL3. However, whether
ADAR1 has effects on ferroptosis in breast cancer cells is largely unknown. In this study, we knocked down
ADAR1 using CRISPR-Cas9 technology or over-expressed
ADAR1 protein using plasmid expressing ADAR1 in MCF-7 and MDA-MB-231 breast cancer cell lines, then detected cell viability, and levels of ROS, MDA, GSH, Fe2+, GPX4 protein and miR-335-5p. We showed that the cell proliferation was inhibited, levels of ROS, MDA, Fe2+, and miR-335-5p were increased, while GSH and GPX4 levels were decreased after loss of ADAR1, compared to the control group. The opposite effects were observed after
ADAR1 overexpression in the cells. Further, we demonstrated that ADAR1-controlled miR-335-5p targeted Sp1 transcription factor of GPX4, a known ferroptosis molecular marker, leading to inhibition of ferroptosis by ADAR1 in breast cancer cells. Moreover, RNA editing activity of
ADAR1 is not essential for inducing ferroptosis. Collectively, loss of ADAR1 induces ferroptosis in breast cancer cells by regulating miR-335-5p/Sp1/GPX4 pathway. The findings may provide insights into the mechanism by which ADAR1 promotes breast cancer progression via inhibiting ferroptosis.