Yang Zhaoting, Cui Yan, Ni Weidong, Kim Seokhyung, Xuan Yanhua
Key Laboratory of Natural Resources of the Changbai Mountain and Functional Molecules, Ministry of Education, Yanbian University, Yanji, 133002, China.
Institute for Regenerative Medicine, Yanbian University College of Medicine, Yanji, 133002, China.
J Cancer Res Clin Oncol. 2017 Feb;143(2):243-254. doi: 10.1007/s00432-016-2273-6. Epub 2016 Sep 28.
The hedgehog (Hh) pathway is involved in cancer stem cell (CSC) maintenance in various tumors. Glioma-associated oncogene homolog 1 (Gli1) is a key mediator of the Hh pathway; however, its expression and clinical significance in esophageal squamous cell carcinoma (ESCC) have not been reported. In this study, we aimed to reveal clinical significance of Gli1 expression in ESCC and further investigate the potential of Gli1 as a CSC regulator of ESCC by comparing its expression with expressions of other stemness genes in ESCC.
We assessed the expressions of Gli1, Sox9, CD44, Sox2, LSD1, and Oct4 in 127 patients' tissue specimens of ESCC using immunohistochemistry and in ESCC cell lines using Western blotting. The relationship of Gli1 expression with clinic-pathologic parameters as well as cell-cycle-regulating genes was investigated. We also investigated the biological pathways that are activated in Gli1-high ESCC using The Cancer Genome Atlas (TCGA) data.
Gli1 expression was observed in 28.3 % of ESCC, and its expression was correlated with the expression of stemness genes, Sox9 (P = 0.003) and CD44 (P = 0.012). And Gli1, CD44, and Sox9 were highly expressed in more poorly differentiated ESCC cell lines such as TE8 and TE1 cells. Notably, Gli1 expression was positively associated with distant metastasis (P = 0.011), increased microvessel density (MVD) (P = 0.002), and expression of cell cycle regulators such as p21, cyclin D1, cyclin E1, and NF-κB (P < 0.05). Sox9 and CD44 expressions in ESCC were also significantly associated with unfavorable clinic-pathologic parameters such as increased MVD, advanced tumor (pT) stage, and higher TNM stage. Moreover, all three potential CSC markers such as Gli1, Sox9, and CD44 were strongly linked to worse clinical outcome and independent poor prognostic factors in overall survival and disease-free survival in ESCC. Gene set enrichment analysis revealed that the Gli1-high-expressing ESCC patients' group was strongly enriched for gene expression signature of Hh signaling pathway, epithelial-mesenchymal transition, and cancer stem cell.
Targeting Gli1, a potential diagnostic marker of ESCC stem cells, will have a profound therapeutic and prognostic value.
刺猬（Hh）信号通路参与多种肿瘤中癌症干细胞（CSC）的维持。胶质瘤相关癌基因同源物1（Gli1）是Hh信号通路的关键介质；然而，其在食管鳞状细胞癌（ESCC）中的表达及临床意义尚未见报道。在本研究中，我们旨在揭示Gli1在ESCC中的临床意义，并通过比较其与ESCC中其他干性基因的表达，进一步研究Gli1作为ESCC的CSC调节因子的潜力。
我们使用免疫组织化学方法评估了127例ESCC患者组织标本中Gli1、Sox9、CD44、Sox2、LSD1和Oct4的表达，并使用蛋白质印迹法评估了ESCC细胞系中的表达。研究了Gli1表达与临床病理参数以及细胞周期调节基因的关系。我们还使用癌症基因组图谱（TCGA）数据研究了Gli1高表达的ESCC中激活的生物学途径。
在28.3%的ESCC中观察到Gli1表达，其表达与干性基因Sox9（P = 0.003）和CD44（P = 0.012）的表达相关。Gli1、CD44和Sox9在分化较差的ESCC细胞系如TE8和TE1细胞中高表达。值得注意的是，Gli1表达与远处转移（P = 0.011）、微血管密度（MVD）增加（P = 0.002）以及细胞周期调节因子如p21、细胞周期蛋白D1、细胞周期蛋白E1和NF-κB的表达呈正相关（P < 0.05）。ESCC中Sox9和CD44的表达也与不良临床病理参数显著相关，如MVD增加、肿瘤（pT）分期进展和TNM分期较高。此外，Gli1、Sox9和CD44这三种潜在的CSC标志物均与ESCC患者更差的临床结局以及总生存和无病生存的独立不良预后因素密切相关。基因集富集分析显示，Gli1高表达的ESCC患者组强烈富集Hh信号通路、上皮-间质转化和癌症干细胞的基因表达特征。
靶向Gli1，一种ESCC干细胞的潜在诊断标志物，将具有深远的治疗和预后价值。
