Department of Pancreato-Biliary Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
Key Laboratory of Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou, China.
Clin Transl Med. 2022 Jun;12(6):e848. doi: 10.1002/ctm2.848.
Intrahepatic cholangiocarcinoma (ICC) is an aggressive cancer with exceedingly poor prognosis, and chemoresistance is a huge challenge for treatment. N6-methyladenosine (m A) modification plays an important role in the progression and chemoresistance of cancers. We aimed to investigate the oncogenic function and therapeutic significance of the m A binding protein, YTH domain family 2 (YTHDF2), in ICC progression and cisplatin-based chemotherapy.
Several independent data sets were used to assess the expression of YTHDF2 in ICC, particularly in chemoresistant ICC. Knockdown and overexpression were used to evaluate the effects of YTHDF2 on tumourigenesis and cisplatin response in ICC. Multi-omics sequencing was performed to identify target genes. RIP, dual luciferase reporter, RNA stability experiment and loss-of-function assays were conducted to study the mechanisms underlying the oncogenic function of YTHDF2. Furthermore, patient-derived xenograft (PDX) model was established to determine the effect of combination treatment of YTHDF2 siRNA and cisplatin in ICC.
Our study showed that YTHDF2 was upregulated in ICC tissues, particularly in chemoresistant ICC tissues, and correlated with poor prognosis. Furthermore, silencing YTHDF2 led to inhibited proliferation, promoted apoptosis and G0/G1 cell cycle arrest. Its downregulation also enhanced DNA damage and sensitised ICC cells to cisplatin. YTHDF2 overexpression exerted the opposite results. Integration analysis using RNA-seq, MeRIP-seq and anti-YTHDF2 RIP-seq elucidated the role of YTHDF2 in tumourigenesis and cisplatin-desensitising function by promoting the degradation of cyclin-dependent kinase inhibitor 1B (CDKN1B) mRNA in an m A-dependent manner. Downregulation of CDKN1B increased the YTHDF2 silencing-induced influence on tumourigenesis and cisplatin response to ICC. In addition, the combination treatment of YTHDF2 siRNA and cisplatin significantly enhanced the anti-tumour effect of cisplatin in a chemoresistant ICC PDX model.
YTHDF2 exhibits tumour oncogenic and cisplatin-desensitising properties, which may offer insight into the development of novel combination therapeutic strategies for ICC.
肝内胆管癌（ICC）是一种侵袭性癌症，预后极差，化疗耐药性是治疗的巨大挑战。N6-甲基腺苷（m A）修饰在癌症的进展和化疗耐药性中发挥重要作用。我们旨在研究 m A 结合蛋白 YTH 结构域家族 2（YTHDF2）在 ICC 进展和基于顺铂的化疗中的致癌功能和治疗意义。
使用多个独立数据集评估 YTHDF2 在 ICC 中的表达，特别是在化疗耐药性 ICC 中的表达。使用敲低和过表达来评估 YTHDF2 对 ICC 肿瘤发生和顺铂反应的影响。进行多组学测序以鉴定靶基因。进行 RIP、双荧光素酶报告、RNA 稳定性实验和功能丧失实验来研究 YTHDF2 致癌功能的机制。此外，建立患者来源的异种移植（PDX）模型以确定 YTHDF2 siRNA 和顺铂联合治疗在 ICC 中的效果。
我们的研究表明，YTHDF2 在 ICC 组织中上调，特别是在化疗耐药性 ICC 组织中上调，并与不良预后相关。此外，沉默 YTHDF2 导致增殖受到抑制、促进凋亡和 G0/G1 细胞周期停滞。其下调还增强了 DNA 损伤并使 ICC 细胞对顺铂敏感。YTHDF2 的过表达则产生相反的结果。使用 RNA-seq、MeRIP-seq 和抗-YTHDF2 RIP-seq 进行的整合分析表明，YTHDF2 通过以 m A 依赖性方式促进细胞周期蛋白依赖性激酶抑制剂 1B（CDKN1B）mRNA 的降解，在肿瘤发生和顺铂脱敏功能中发挥作用。CDKN1B 的下调增加了 YTHDF2 沉默对 ICC 肿瘤发生和顺铂反应的影响。此外，YTHDF2 siRNA 和顺铂的联合治疗在化疗耐药性 ICC PDX 模型中显著增强了顺铂的抗肿瘤作用。
YTHDF2 具有肿瘤致癌和顺铂脱敏特性，这可能为 ICC 新型联合治疗策略的发展提供新的思路。
