m6A demethylase ALKBH5 inhibits pancreatic cancer tumorigenesis by decreasing WIF-1 RNA methylation and mediating Wnt signaling
m6A demethylase ALKBH5 inhibits pancreatic cancer tumorigenesis by decreasing WIF-1 RNA methylation and mediating Wnt signaling
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m(6)A 去甲基化酶 ALKBH5 通过减少 WIF-1 RNA 甲基化和介导 Wnt 信号传导抑制胰腺癌肿瘤发生
DOI：
10.1186/s12943-019-1128-6
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发表时间：
2020-01-06
期刊：
影响因子：
37.3
通讯作者：
Shimamoto, Fumio
中科院分区：
文献类型：
--
作者：
Tang, Bo;Yang, Yihua;Shimamoto, Fumio
背景胰腺癌是最致命的癌症之一，诊断和预后极差，化疗耐药性仍然是一个主要挑战。动态和可逆的N-6-甲基腺苷（m（6）A）RNA修饰已成为表观遗传基因调控的新层次。方法采用qRT-PCR和免疫组化技术检测正常胰腺组织和胰腺癌组织中ALKBH 5的表达。通过克隆形成、化疗敏感性检测和Western印迹分析来评估癌细胞增殖和化疗抗性。m（6）进行A-seq以鉴定目的基因。我们评估了ALKBH 5在体内和体外模型中的抑制作用。结果：在吉西他滨处理的患者来源的异种移植（PDX）模型中，m（6）A脱甲基酶ALKBH 5下调，其过表达使胰腺导管腺癌（PDAC）细胞对化疗敏感。ALKBH 5水平降低预示PDAC和多种其他癌症的临床结局较差。此外，沉默ALKBH 5显着增加PDAC细胞的增殖，迁移和侵袭在体外和体内，而其过表达引起相反的效果。总体m（6）A谱显示某些ALKBH 5靶基因的表达改变，包括Wnt抑制因子1（WIF-1），其与WIF-1反式激活和Wnt通路的介导相关。结论ALKBH 5具有抑瘤和化疗增敏作用，为进一步研究m（6）A甲基化在PDAC中的作用提供了新的思路。
Background Pancreatic cancer is one of the most lethal types of cancer with extremely poor diagnosis and prognosis, and chemo-resistance remains a major challenge. The dynamic and reversible N-6-methyladenosine (m(6)A) RNA modification has emerged as a new layer of epigenetic gene regulation. Methods qRT-PCR and IHC were applied to examine ALKBH5 levels in normal and pancreatic cancer tissues. Cancer cell proliferation and chemo-resistance were evaluated by clonogenic formation, chemosensitivity detection, and Western blotting assays. m(6)A-seq was performed to identify target genes. We evaluated the inhibitory effect of ALKBH5 in both in vivo and in vitro models. Results Here, we show that m(6)A demethylase ALKBH5 is downregulated in gemcitabine-treated patient-derived xenograft (PDX) model and its overexpression sensitized pancreatic ductal adenocarcinoma (PDAC) cells to chemotherapy. Decreased ALKBH5 levels predicts poor clinical outcome in PDAC and multiple other cancers. Furthermore, silencing ALKBH5 remarkably increases PDAC cell proliferation, migration, and invasion both in vitro and in vivo, whereas its overexpression causes the opposite effects. Global m(6)A profile revealed altered expression of certain ALKBH5 target genes, including Wnt inhibitory factor 1 (WIF-1), which is correlated with WIF-1 transactivation and mediation of the Wnt pathway. Conclusions Our work uncovers the tumor suppressive and chemo-sensitizing function for ALKBH5, which provides insight into critical roles of m(6)A methylation in PDAC.