Department of Thoracic Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
The Frist People's Hospital, Chongqing Liang Jiang New Area, Chongqing, China.
Cancer Med. 2022 Dec;11(23):4555-4574. doi: 10.1002/cam4.4795. Epub 2022 May 24.
Long noncoding RNAs (lncRNAs) are implicated in the oncogenesis and metastasis of multiple human cancers. Nonetheless, the precise molecular mechanisms underlying the oncogenic role of lncRNA in esophageal squamous cell carcinoma (ESCC) remains to be clarified.
The expression of GK intronic transcript 1 (GK-IT1) was analyzed using ESCC RNA-seq data from The Cancer Genome Atlas database. Quantitative real-time PCR was used to measure the expression of GK-IT1 in ESCC clinical samples and cells. The correlation between GK-IT1 expression and clinicopathological variables was examined using chi-squared tests. Kaplan-Meier survival and Cox regression analyses were employed to generate the survival curve and assess the prognostic value of GK-IT1. Functional experiments were utilized to explore the role of GK-IT1 in promoting cell migration, invasion, proliferation, and suppressing apoptosis and autophagy in ESCC. To understand the mechanism, an RNA pulldown assay, RNA immunoprecipitation, agarose gel electrophoresis, immunofluorescence, and co-immunoprecipitation assays were used.
In this study we identified an unreported lncRNA, termed GK-IT1 that was aberrantly overexpressed in ESCC tissues and cells. GK-IT1 was closely associated with advanced clinical stage, and it was an independent prognostic indicator of ESCC. Functional assays verified that GK-IT1 significantly promoted ESCC proliferation, invasion, and migration, and suppressed ESCC apoptosis and autophagy. Furthermore, tumorigenesis experiments in nude mice indicated that GK-IT1 promoted ESCC tumor growth and metastasis. Mechanistically, GK-IT1 competitively bound to mitogen-activated protein kinase 1 (MAPK1) to prevent the interaction between dual specificity phosphatase 6 (DUSP6) and MAPK1, thereby controlling the phosphorylation of MAPK1 and promoting ESCC progression.
Our study revealed that GK-IT1 competed with DUSP6 to attenuate the interaction between DUSP6 and MAPK1, leading to activation of the ERK/MAPK pathway, thereby promoting progression of ESCC. Our research indicated that GK-IT1 served as a novel potential target for the diagnosis and treatment of ESCC.
长链非编码 RNA（lncRNA）参与多种人类癌症的发生和转移。然而，lncRNA 在食管鳞状细胞癌（ESCC）中的致癌作用的确切分子机制仍有待阐明。
使用来自癌症基因组图谱（TCGA）数据库的 ESCC RNA-seq 数据分析 GK 内含子转录本 1（GK-IT1）的表达。使用定量实时 PCR 测量 ESCC 临床样本和细胞中 GK-IT1 的表达。使用卡方检验检查 GK-IT1 表达与临床病理变量之间的相关性。使用 Kaplan-Meier 生存和 Cox 回归分析生成生存曲线并评估 GK-IT1 的预后价值。利用功能实验探索 GK-IT1 在促进 ESCC 细胞迁移、侵袭、增殖以及抑制细胞凋亡和自噬中的作用。为了了解其机制，我们进行了 RNA 下拉测定、RNA 免疫沉淀、琼脂糖凝胶电泳、免疫荧光和共免疫沉淀测定。
在这项研究中，我们鉴定了一种未被报道的 lncRNA，称为 GK-IT1，它在 ESCC 组织和细胞中异常高表达。GK-IT1 与晚期临床分期密切相关，是 ESCC 的独立预后指标。功能测定验证了 GK-IT1 可显著促进 ESCC 的增殖、侵袭和迁移，并抑制 ESCC 的凋亡和自噬。此外，裸鼠肿瘤生成实验表明 GK-IT1 促进了 ESCC 肿瘤的生长和转移。机制上，GK-IT1 竞争性地与丝裂原活化蛋白激酶 1（MAPK1）结合，防止双特异性磷酸酶 6（DUSP6）与 MAPK1 之间的相互作用，从而控制 MAPK1 的磷酸化并促进 ESCC 的进展。
我们的研究揭示了 GK-IT1 与 DUSP6 竞争，减弱了 DUSP6 与 MAPK1 的相互作用，导致 ERK/MAPK 通路的激活，从而促进 ESCC 的进展。我们的研究表明 GK-IT1 可作为 ESCC 诊断和治疗的新的潜在靶点。
