Department of Urology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China.
J Cell Biochem. 2019 Apr;120(4):6471-6481. doi: 10.1002/jcb.27938. Epub 2018 Nov 11.
Bladder cancer (BCa) is the most common malignant tumor in the urinary system. Growing evidence suggests that as a tumor suppressor gene, hypermethylated in cancer 1 (HIC1) is correlated with various malignancies in the modulation of tumor progression. This study aims to investigate the effect of HIC1 on regulating the proliferation, migration, and invasion of BCa.
Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot (WB) were used to evaluate the expression of HIC1 messenger RNA and protein in human BCa tissues and cells. Proliferation, migration and invasion assays, and flow cytometry assay were performed to assess the biological functional role of HIC1 in BCa. Co-immunoprecipitation (Co-IP) examined the protein-protein interaction. The signaling pathways involved in the mode of action of HIC1 in BCa were also investigated.
HIC1 was found downregulated in tested samples. Cloning formation assay and cell-proliferation activity analysis showed that overexpression of HIC1 significantly inhibited the proliferation of BCa cells, while knockdown led to the opposite, namely the promotion of the proliferation. Flow cytometry assay confirmed the arrest of the cell cycle at the G1 phase with overexpression of HIC1 observed. Moreover, HIC1 inhibited migration and invasion of BCa. Co-IP showed the binding between YAP (yes-associated protein) and TEAD (TEA domain/transcription enhancer factor family members) as well as the cancerostatic activity of HIC1, partially manifested via its negative regulation of YAP signaling pathway.
Our data unprecedently showed that HIC1 was responsible for the inhibition of proliferation, migration, and invasion of BCa via the YAP signaling pathway. These findings suggested that therapeutic strategies regulating HIC1 expression might provide effective treatments for BCa.
膀胱癌（BCa）是泌尿系统最常见的恶性肿瘤。越来越多的证据表明，作为一种肿瘤抑制基因，异常高甲基化 1（HIC1）与多种恶性肿瘤在肿瘤进展的调节中相关。本研究旨在探讨 HIC1 对调节膀胱癌增殖、迁移和侵袭的影响。
采用定量逆转录聚合酶链反应（qRT-PCR）和 Western blot（WB）检测 HIC1 信使 RNA 和蛋白在人膀胱癌组织和细胞中的表达。进行增殖、迁移和侵袭测定以及流式细胞术分析，以评估 HIC1 在 BCa 中的生物学功能作用。采用免疫共沉淀（Co-IP）检测蛋白-蛋白相互作用。还研究了 HIC1 在 BCa 作用模式中涉及的信号通路。
发现 HIC1 在测试样本中下调。克隆形成测定和细胞增殖活性分析表明，HIC1 的过表达显著抑制了 BCa 细胞的增殖，而敲低则导致相反的结果，即促进增殖。流式细胞术分析证实 HIC1 的过表达导致细胞周期停滞在 G1 期。此外，HIC1 抑制了 BCa 的迁移和侵袭。Co-IP 显示 YAP（yes-associated protein）和 TEAD（TEA 结构域/转录增强因子家族成员）之间的结合以及 HIC1 的抗癌活性，部分通过其对 YAP 信号通路的负调控来表现。
我们的数据前所未有地表明，HIC1 通过 YAP 信号通路负责抑制 BCa 的增殖、迁移和侵袭。这些发现表明，调节 HIC1 表达的治疗策略可能为 BCa 提供有效的治疗方法。
