Department of Plastic and Reconstructive Surgery, Shanghai 9th People's Hospital, Shanghai Jiao Tong University School of Medicine, 639 Zhi Zao Ju Road, Shanghai, 200011, PR China.
Department of Plastic and Reconstructive Surgery, Shanghai 9th People's Hospital, Shanghai Jiao Tong University School of Medicine, 639 Zhi Zao Ju Road, Shanghai, 200011, PR China.
Biochem Biophys Res Commun. 2019 Jul 23;515(2):310-317. doi: 10.1016/j.bbrc.2019.05.155. Epub 2019 May 29.
The cutaneous squamous cell carcinoma (cSCC) originates from epithelial stem cells through the dysregulation of self-renewal and differentiation. Recent studies have identified methyltransferase-like 3 (METTL3)-mediated N6-methyladenosine (mA) modification as key regulator of fate of stem cells. However, little is known about the functional importance of METTL3 in cSCC. Here, Western blot and immunohistochemistry were used to investigate the METTL3 levels in cSCC tissues. Functional experiments including surface marker detection, Brdu incorporation assay, colony forming assay, mA dot blot and tumor xenograft assay were performed to investigate the properties in cSCC cell lines after METTL3 knock down. The expression of METTL3 was up-regulated in cSCC samples. METTL3 knock down impaired cSCC cell stem-like properties, including colony forming ability in vitro and tumorigenicity in vivo. Furthermore, METTL3 knock down and methylation inhibitor cycloleucine could decrease the mA levels and the expression of ΔNp63 in cSCC. Exogenous expression of ΔNp63 partially restored the cell proliferation of METTL3-knockdown cSCC cells. Therefore, our data indicated the mA methyltransferases METTL3 as a critical gene in regulating tumorigeneis of cSCC.
皮肤鳞状细胞癌（cSCC）起源于上皮干细胞，通过自我更新和分化的失调。最近的研究已经确定了甲基转移酶样 3（METTL3）介导的 N6-甲基腺苷（mA）修饰作为干细胞命运的关键调节剂。然而，关于 METTL3 在 cSCC 中的功能重要性知之甚少。在这里，使用 Western blot 和免疫组织化学检测 cSCC 组织中的 METTL3 水平。进行功能实验，包括表面标志物检测、Brdu 掺入测定、集落形成测定、mA 点印迹和肿瘤异种移植测定，以研究 METTL3 敲低后 cSCC 细胞系的特性。METTL3 在 cSCC 样本中表达上调。METTL3 敲低削弱了 cSCC 细胞的干细胞样特性，包括体外集落形成能力和体内致瘤性。此外，METTL3 敲低和甲基化抑制剂环亮氨酸可降低 mA 水平和 cSCC 中的ΔNp63 表达。外源性表达 ΔNp63 部分恢复了 METTL3 敲低的 cSCC 细胞的增殖。因此，我们的数据表明 mA 甲基转移酶 METTL3 是调节 cSCC 肿瘤发生的关键基因。
