Zhou Menghan, Yu Shenling, Liu Yue, Shu Shihui, Xu Ying, Liu Min, Ge Yanping, Fan Hong
Department of Medical Genetics and Developmental Biology, Medical School of Southeast University, The Key Laboratory of Developmental Genes and Human Diseases, Ministry of Education, Southeast University, Nanjing, 210000, China.
School of Life Science and Technology, Southeast University, Nanjing, 210000, China.
Dig Dis Sci. 2023 Jun;68(6):2463-2473. doi: 10.1007/s10620-023-07892-7. Epub 2023 Mar 18.
Histone methylations are generally considered to play an important role in multiple cancers by regulating cancer-related genes.
This study aims to investigate the effects of H3K27me3-mediated inactivation of tumor suppressor gene SFRP1 and its function in esophageal squamous cell carcinoma (ESCC).
We performed ChIP-seq on H3K27me3-enriched genomic DNA fragments in ESCC cells to screen out tumor suppressor genes that may be regulated by H3K27me3. ChIP-qPCR and Western blot were employed to explore the regulating mechanisms between H3K27me3 and SFRP1. Expression level of SFRP1 was assessed by quantitative real-time polymerase chain reaction (q-PCR) in 29 pairs of ESCC surgical samples. SFRP1 function in ESCC cells were detected by cell proliferation assay, colony formation assay and wound-healing assay.
Our results indicated that H3K27me3 was widely distributed in the genome of ESCC cells. Specifically, we found that H3K27me3 deposited on the upstream region of SFRP1 promoter and inactivated SFRP1 expression. Furthermore, we found SFRP1 was significantly down-regulated in ESCC tissues compared with the adjacent non-tumor tissues, and SFRP1 expression was significantly associated with TNM stage and lymph node metastasis. In vitro cell-based assay indicated that over-expression of SFRP1 significantly suppressed cell proliferation and negatively correlated with the expression of β-catenin in the nucleus.
Our study revealed a previously unrecognized finding that H3K27me3-mediated SFRP1 inhibit the cell proliferation of ESCC through inactivation of Wnt/β-catenin signaling pathway.
组蛋白甲基化通常被认为通过调控癌症相关基因在多种癌症中发挥重要作用。
本研究旨在探讨H3K27me3介导的肿瘤抑制基因SFRP1失活及其在食管鳞状细胞癌（ESCC）中的作用。
我们对ESCC细胞中富含H3K27me3的基因组DNA片段进行了染色质免疫沉淀测序（ChIP-seq），以筛选出可能受H3K27me3调控的肿瘤抑制基因。采用染色质免疫沉淀定量聚合酶链反应（ChIP-qPCR）和蛋白质免疫印迹法（Western blot）探讨H3K27me3与SFRP1之间的调控机制。通过定量实时聚合酶链反应（q-PCR）检测29对ESCC手术样本中SFRP1的表达水平。采用细胞增殖试验、集落形成试验和伤口愈合试验检测SFRP1在ESCC细胞中的功能。
我们的结果表明，H3K27me3广泛分布于ESCC细胞基因组中。具体而言，我们发现H3K27me3沉积在SFRP1启动子上游区域并使SFRP1表达失活。此外，我们发现与相邻非肿瘤组织相比，ESCC组织中SFRP1明显下调，且SFRP1表达与TNM分期和淋巴结转移显著相关。体外细胞试验表明，SFRP1的过表达显著抑制细胞增殖，且与细胞核中β-连环蛋白的表达呈负相关。
我们的研究揭示了一个此前未被认识的发现，即H3K27me3介导的SFRP1通过使Wnt/β-连环蛋白信号通路失活来抑制ESCC细胞增殖。
