Department of Pulmonary and Critical Care Medicine, The 8th Medical Center of Chinese, PLA General Hospital, Beijing, 100091, China.
Department of Oncology, Hainan Hospital of PLA General Hospital, Haitang District, Sanya, 572013, China.
J Cancer Res Clin Oncol. 2022 Dec;148(12):3485-3499. doi: 10.1007/s00432-022-04128-5. Epub 2022 Jul 30.
Lung cancer (LC) remains a threatening health issue worldwide. Methyltransferase-like protein 3 (METTL3) is imperative in carcinogenesis via m6A modification of microRNAs (miRNAs). This study estimated the effect of METTL3 in LC by regulating m6A methylation-mediated pri-miR-663 processing.
miR-663 expression in 4 LC cell lines and normal HBE cells was determined using RT-qPCR. A549 and PC9 LC cells selected for in vitro studies were transfected with miR-663 mimics or inhibitor. Cell viability, migration, invasion, proliferation, and apoptosis were detected by CCK-8, Transwell, EdU, and flow cytometry assays. The downstream target genes and binding sites of miR-663 were predicted via Starbase database and validated by dual-luciferase assay. LC cells were delivered with oe-METTL3/sh-METTL3. Crosslinking between METTL3 and DGCR8 was verified by co-immunoprecipitation. Levels of m6A, miR-663, and pri-miR-663 were measured by m6A dot blot assay and RT-qPCR. m6A modification of pri-miR-663 was verified by Me-RIP assay. Finally, the effects of METTL3 in vivo were ascertained by tumor xenograft in nude mice.
miR-663 was upregulated in LC cells, and miR-663 overexpression promoted cell proliferation, migration, invasion, and inhibited apoptosis, but miR-663 knockdown exerted the opposite effects. miR-663 repressed SOCS6 expression. SOCS6 overexpression annulled the promotion of miR-663 on LC cell growth. METTL3 bound to DGCR8, and METTL3 silencing elevated the levels of pri-miR-663 and m6A methylation-modified pri-miR-663, and suppressed miR-663 maturation and miR-663 expression. METTL3 facilitated tumor growth in mice through the miR-663/SOCS6 axis.
METTL3 promotes LC progression by accelerating m6A methylation-mediated pri-miR-663 processing and repressing SOCS6.
肺癌（LC）仍然是全球范围内具有威胁性的健康问题。甲基转移酶样蛋白 3（METTL3）通过 miRNA（miRNA）的 m6A 修饰在致癌作用中至关重要。本研究通过调节 m6A 甲基化介导的 pri-miR-663 加工来估计 METTL3 在 LC 中的作用。
采用 RT-qPCR 检测 4 种 LC 细胞系和正常 HBE 细胞中的 miR-663 表达。选择 A549 和 PC9 LC 细胞进行体外研究，并用 miR-663 模拟物或抑制剂转染。通过 CCK-8、Transwell、EdU 和流式细胞术检测细胞活力、迁移、侵袭、增殖和凋亡。通过 Starbase 数据库预测 miR-663 的下游靶基因和结合位点，并通过双荧光素酶报告基因实验验证。将 oe-METTL3/sh-METTL3 递送至 LC 细胞。通过 co-immunoprecipitation 验证 METTL3 和 DGCR8 之间的交联。通过 m6A 斑点印迹和 RT-qPCR 检测 m6A、miR-663 和 pri-miR-663 的水平。通过 Me-RIP 测定验证 pri-miR-663 的 m6A 修饰。最后，通过裸鼠肿瘤异种移植确定 METTL3 在体内的作用。
miR-663 在 LC 细胞中上调，miR-663 过表达促进细胞增殖、迁移、侵袭，抑制细胞凋亡，但 miR-663 敲低则产生相反的效果。miR-663 抑制 SOCS6 表达。SOCS6 过表达消除了 miR-663 对 LC 细胞生长的促进作用。METTL3 与 DGCR8 结合，METTL3 沉默增加了 pri-miR-663 的水平和 m6A 修饰的 pri-miR-663，抑制了 miR-663 的成熟和 miR-663 的表达。METTL3 通过 miR-663/SOCS6 轴促进小鼠肿瘤生长。
METTL3 通过加速 m6A 甲基化介导的 pri-miR-663 加工和抑制 SOCS6 促进 LC 进展。
