Department of Biochemistry and Molecular Biology, Medical College of Shantou University, Shantou, China; Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California.
Cancer Science Institute of Singapore, National University of Singapore, Singapore.
Gastroenterology. 2018 Jun;154(8):2137-2151.e1. doi: 10.1053/j.gastro.2018.02.018. Epub 2018 Feb 15.
BACKGROUND & AIMS: Long non-coding RNAs (lncRNAs) are expressed in tissue-specific pattern, but it is not clear how these are regulated. We aimed to identify squamous cell carcinoma (SCC)-specific lncRNAs and investigate mechanisms that control their expression and function.
We studied expression patterns and functions of 4 SCC-specific lncRNAs. We obtained 113 esophageal SCC (ESCC) and matched non-tumor esophageal tissues from a hospital in Shantou City, China, and performed quantitative reverse transcription polymerase chain reaction assays to measure expression levels of LINC01503. We collected clinical data from patients and compared expression levels with survival times. LINC01503 was knocked down using small interfering RNAs and oligonucleotides in TE7, TE5, and KYSE510 cell lines and overexpressed in KYSE30 cells. Cells were analyzed by chromatin immunoprecipitation sequencing, luciferase reporter assays, colony formation, migration and invasion, and mass spectrometry analyses. Cells were injected into nude mice and growth of xenograft tumors was measured. LINC01503 interaction with proteins was studied using fluorescence in situ hybridization, RNA pulldown, and RNA immunoprecipitation analyses.
We identified a lncRNA, LINC01503, which is regulated by a super enhancer and is expressed at significantly higher levels in esophageal and head and neck SCCs than in non-tumor tissues. High levels in SCCs correlated with shorter survival times of patients. The transcription factor TP63 bound to the super enhancer at the LINC01503 locus and activated its transcription. Expression of LINC01503 in ESCC cell lines increased their proliferation, colony formation, migration, and invasion. Knockdown of LINC01503 in SCC cells reduced their proliferation, colony formation, migration, and invasion, and the growth of xenograft tumors in nude mice. Expression of LINC01503 in ESCC cell lines reduced ERK2 dephosphorylation by DUSP6, leading to activation of ERK signaling via MAPK. LINC01503 disrupted the interaction between EBP1 and the p85 subunit of PI3K, increasing AKT signaling.
We identified an lncRNA, LINC01503, which is increased in SCC cells compared with non-tumor cells. Increased expression of LINC01503 promotes ESCC cell proliferation, migration, invasion, and growth of xenograft tumors. It might be developed as a biomarker of aggressive SCCs in patients.
长链非编码 RNA（lncRNA）在组织特异性模式中表达，但这些如何受到调控尚不清楚。我们旨在鉴定鳞状细胞癌（SCC）特异性 lncRNA，并研究控制其表达和功能的机制。
我们研究了 4 种 SCC 特异性 lncRNA 的表达模式和功能。我们从中国汕头市一家医院获得了 113 例食管鳞状细胞癌（ESCC）和匹配的非肿瘤食管组织，并进行了定量逆转录聚合酶链反应（qRT-PCR）检测，以测量 LINC01503 的表达水平。我们从患者那里收集了临床数据，并将表达水平与生存时间进行了比较。我们使用小干扰 RNA（siRNA）和寡核苷酸在 TE7、TE5 和 KYSE510 细胞系中敲低 LINC01503，并在 KYSE30 细胞中过表达 LINC01503。通过染色质免疫沉淀测序、荧光素酶报告基因检测、集落形成、迁移和侵袭以及质谱分析对细胞进行分析。将细胞注射到裸鼠中，并测量异种移植肿瘤的生长情况。使用荧光原位杂交（FISH）、RNA 下拉和 RNA 免疫沉淀（RIP）分析研究 LINC01503 与蛋白质的相互作用。
我们鉴定出一种 lncRNA，LINC01503，它受超级增强子调控，在食管和头颈部 SCC 中的表达水平明显高于非肿瘤组织。SCC 中的高表达与患者的生存时间较短相关。转录因子 TP63 与 LINC01503 基因座的超级增强子结合，并激活其转录。在 ESCC 细胞系中表达 LINC01503 可增加其增殖、集落形成、迁移和侵袭。在 SCC 细胞中敲低 LINC01503 可降低其增殖、集落形成、迁移和侵袭能力，并降低裸鼠异种移植肿瘤的生长。在 ESCC 细胞系中表达 LINC01503 可降低 DUSP6 对 ERK2 的去磷酸化作用，从而通过 MAPK 激活 ERK 信号。LINC01503 破坏了 EBP1 与 PI3K p85 亚基之间的相互作用，增加了 AKT 信号。
我们鉴定出一种 lncRNA，LINC01503，它在 SCC 细胞中的表达高于非肿瘤细胞。LINC01503 的高表达促进 ESCC 细胞的增殖、迁移、侵袭和异种移植肿瘤的生长。它可能被开发为患者侵袭性 SCC 的生物标志物。
