Department of Cancer Biotherapy Center, Yunnan Cancer Hospital, the Third Affiliated Hospital of Kunming Medical University, Kunming, 650118, Yunnan, China.
Department of Rehabilitation and Palliative Medicine, Yunnan Cancer Hospital, the Third Affiliated Hospital of Kunming Medical University, Number 519 Kunzhou Road, Kunming, 650118, Yunnan, China.
J Transl Med. 2023 Jun 12;21(1):382. doi: 10.1186/s12967-023-04190-8.
Accumulating data indicate that N6-methyladenosine (mA) RNA methylation and lncRNA deregulation act crucial roles in cancer progression. Heterogeneous nuclear ribonucleoprotein A2B1 (HNRNPA2B1) as an mA "reader" has been reported to be an oncogene in multiple malignancies. We herein aimed to elucidate the role and underlying mechanism by which HNRNPA2B1-mediated mA modification of lncRNAs contributes to non-small cell lung cancer (NSCLC).
The expression levels of HNRNPA2B1 and their association with the clinicopathological characteristics and prognosis in NSCLC were determined by RT-qPCR, Western blot, immunohistochemistry and TCGA dataset. Then, the role of HNRNPA2B1 in NSCLC cells was assessed by in vitro functional experiments and in vivo tumorigenesis and lung metastasis models. HNRNPA2B1-mediated mA modification of lncRNAs was screened by mA-lncRNA epi-transcriptomic microarray and verified by methylated RNA immunoprecipitation (Me-RIP). The lncRNA MEG3-specific binding with miR-21-5p was evaluated by luciferase gene report and RIP assays. The effects of HNRNPA2B1 and (or) lncRNA MEG3 on miR-21-5p/PTEN/PI3K/AKT signaling were examined by RT-qPCR and Western blot analyses.
We found that upregulation of HNRNPA2B1 was associated with distant metastasis and poor survival, representing an independent prognostic factor in patients with NSCLC. Knockdown of HNRNPA2B1 impaired cell proliferation and metastasis in vitro and in vivo, whereas ectopic expression of HNRNPA2B1 possessed the opposite effects. Mechanical investigations revealed that lncRNA MEG3 was an mA target of HNRNPA2B1 and inhibition of HNRNPA2B1 decreased MEG3 mA levels but increased its mRNA levels. Furthermore, lncRNA MEG3 could act as a sponge of miR-21-5p to upregulate PTEN and inactivate PI3K/AKT signaling, leading to the suppression of cell proliferation and invasion. Low expression of lncRNA MEG3 or elevated expression of miR-21-5p indicated poor survival in patients with NSCLC.
Our findings uncover that HNRNPA2B1-mediated mA modification of lncRNA MEG3 promotes tumorigenesis and metastasis of NSCLC cells by regulating miR-21-5p/PTEN axis and may provide a therapeutic target for NSCLC.
越来越多的证据表明，N6-甲基腺苷（mA）RNA 甲基化和长链非编码 RNA 失调在癌症进展中起关键作用。异质性核核糖核蛋白 A2B1（HNRNPA2B1）作为 mA“阅读器”，已被报道在多种恶性肿瘤中为癌基因。本研究旨在阐明 HNRNPA2B1 介导的 lncRNA mA 修饰如何促进非小细胞肺癌（NSCLC）。
通过 RT-qPCR、Western blot、免疫组化和 TCGA 数据集确定 HNRNPA2B1 的表达水平及其与 NSCLC 临床病理特征和预后的关系。通过体外功能实验和体内肿瘤发生和肺转移模型评估 HNRNPA2B1 在 NSCLC 细胞中的作用。通过 mA-lncRNA epi 转录组微阵列筛选 HNRNPA2B1 介导的 lncRNA mA 修饰，并通过甲基化 RNA 免疫沉淀（Me-RIP）验证。通过荧光素酶基因报告和 RIP 测定评估长链非编码 RNA MEG3 与 miR-21-5p 的特异性结合。通过 RT-qPCR 和 Western blot 分析研究 HNRNPA2B1 和（或）lncRNA MEG3 对 miR-21-5p/PTEN/PI3K/AKT 信号通路的影响。
我们发现 HNRNPA2B1 的上调与远处转移和不良预后相关，是 NSCLC 患者的独立预后因素。HNRNPA2B1 敲低可抑制 NSCLC 细胞的体外和体内增殖和转移，而过表达 HNRNPA2B1 则具有相反的作用。机制研究表明，lncRNA MEG3 是 HNRNPA2B1 的 mA 靶点，抑制 HNRNPA2B1 可降低 MEG3 mA 水平，但增加其 mRNA 水平。此外，lncRNA MEG3 可以作为 miR-21-5p 的海绵，上调 PTEN 并使 PI3K/AKT 信号失活，从而抑制细胞增殖和侵袭。在 NSCLC 患者中，lncRNA MEG3 表达水平低或 miR-21-5p 表达水平高提示预后不良。
本研究揭示了 HNRNPA2B1 介导的 lncRNA MEG3 的 mA 修饰通过调节 miR-21-5p/PTEN 轴促进 NSCLC 细胞的发生和转移，可为 NSCLC 提供治疗靶点。
