Yu Chuan, Yao Xiaomin, Zhao Linjie, Wang Ping, Zhang Qian, Zhao Chengjian, Yao Shaohua, Wei Yuquan
State Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy, West China Hospital, College of Life Science, Sichuan University, Chengdu, 610041, People's Republic of China.
State Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy, West China Hospital, College of Life Science, Sichuan University, Chengdu, 610041, People's Republic of China.
Neoplasia. 2017 Aug;19(8):606-616. doi: 10.1016/j.neo.2017.05.001. Epub 2017 Jun 24.
Wolf-Hirschhorn syndrome candidate 1 (WHSC1) is a histone 3 lysine 36 (H3K36) specific methyltransferase that is frequently deleted in Wolf-Hirschhorn syndrome (WHS). Whsc1 is also found mutated in a subgroup of B-cell derived malignant diseases by genomic translocation or point mutation, both of which resulted in hyperactivity of WHSC1 mediated H3K36 methylation and uncontrolled cell proliferation, suggesting that whsc1 functions as an oncogene. However, here we provided evidences to show that whsc1 also has tumor suppressor functions. We used zebrafish as an in vivo model and generated homozygous whsc1 mutant lines via clustered regularly interspaced short palindromic repeats-associated protein Cas9 (CRISPR/Cas9) technology. Then western-blot (WB) and immunofluorescence (IF) were performed to analysis the expression level of H3K36Me2 and H3K36Me3, and we identified the diseased tissue via hematoxylin-eosin (HE) staining, IF staining or immunohistochemistry (IHC). Whsc1 lose-of-function led to significant decrease in di- and tri-methylation of H3K36. A series of WHS related phenotypes were found in whsc1 zebrafish, including growth retardation, neural development defects and heart failure. In addition, loss of function of whsc1 led to defects in the development of swim bladder, possibly through the dis-regulation of key genes in swim bladder organogenesis and inhibition of progenitor cell differentiation, which was correlated with its expression in this organ during embryonic development. At later stage, these whsc1 zebrafishes are inclined to grow tumors in the swim bladder. Our work suggested that whsc1 may function as a tumor suppressor by governing progenitor cell differentiation.
沃尔夫-赫希霍恩综合征候选基因1（WHSC1）是一种组蛋白3赖氨酸36（H3K36）特异性甲基转移酶，在沃尔夫-赫希霍恩综合征（WHS）中经常缺失。在B细胞来源的恶性疾病亚组中也发现Whsc1通过基因组易位或点突变发生突变，这两种情况均导致WHSC1介导的H3K36甲基化活性增强和细胞增殖失控，提示Whsc1作为一种癌基因发挥作用。然而，我们在此提供证据表明Whsc1也具有肿瘤抑制功能。我们以斑马鱼作为体内模型，通过成簇规律间隔短回文重复序列相关蛋白Cas9（CRISPR/Cas9）技术构建了纯合Whsc1突变系。然后进行蛋白质免疫印迹（WB）和免疫荧光（IF）分析H3K36Me2和H3K36Me3的表达水平，并通过苏木精-伊红（HE）染色、IF染色或免疫组织化学（IHC）鉴定病变组织。Whsc1功能缺失导致H3K36二甲基化和三甲基化显著降低。在Whsc1斑马鱼中发现了一系列与WHS相关的表型，包括生长迟缓、神经发育缺陷和心力衰竭。此外，Whsc1功能缺失导致鳔发育缺陷，可能是通过扰乱鳔器官发生中的关键基因和抑制祖细胞分化，这与其在胚胎发育期间在该器官中的表达相关。在后期，这些Whsc1斑马鱼倾向于在鳔中发生肿瘤。我们的研究表明，Whsc1可能通过调控祖细胞分化发挥肿瘤抑制作用。
