Research Report
Copyright ©2014 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jul 7, 2014; 20(25): 8139-8150
Published online Jul 7, 2014. doi: 10.3748/wjg.v20.i25.8139
Screening of lymph nodes metastasis associated lncRNAs in colorectal cancer patients
Jun Han, Long-Fei Rong, Chuan-Bin Shi, Xiao-Gang Dong, Jie Wang, Bao-Lin Wang, Hao Wen, Zhen-Yu He
Jun Han, Long-Fei Rong, Xiao-Gang Dong, Jie Wang, Bao-Lin Wang, Hao Wen, Zhen-Yu He, Department of General Surgery, Second Affiliated Hospital of Nanjing Medical University, Nanjing 210011, Jiangsu Province, China
Chuan-Bin Shi, Department of Pathology, Second Affiliated Hospital of Nanjing Medical University, Nanjing 210011, Jiangsu Province, China
Author contributions: Han J, Rong LF and He ZY designed the research; Shi CB, Dong XG, Wang J, Wang BL and Wen H performed the research and analyzed the data; Han J and Rong LF wrote the paper; Han J and Rong LF contributed equally to this work.
Supported by Natural Science Foundation Project of Jiangsu Province, No. BK2012872; and the Science and Technology Projects, Health Department of Jiangsu Province, No. H201207
Correspondence to: Zhen-Yu He, PhD, Department of General Surgery, Second Affiliated Hospital of Nanjing Medical University, 121 Jiangjiayuan Road, Nanjing 210011, Jiangsu Province, China. hezhenyu1967@163.com
Telephone: +86-25-58509900  Fax: +86-25-58509900
Received: November 15, 2013
Revised: February 15, 2014
Accepted: May 12, 2014
Published online: July 7, 2014
Processing time: 229 Days and 17.2 Hours
Abstract

AIM: To screen lymph nodes metastasis associated long noncoding RNAs (lncRNAs) in colorectal cancer through microarray analysis.

METHODS: Metastatic lymph node (MLN), normal lymph node (NLN) and tumor tissues of 3 colorectal cancer (CRC) patients were collected during the operation and validated by pathological examinations. RNAs were extracted from MLN, NLN, and cancer tissues separately. RNA quantity and quality were measured with a NanoDrop ND-1000 spectrophotometer and RNA integrity was assessed by standard denaturing agarose electrophoresis. Agilent Feature Extraction Software (Version 11.0.1.1) was used to analyze acquired array images. Four differently expressed lncRNAs were confirmed by quantitative real-time polymerase chain reaction (qRT-PCR) in 26 subsets of MLN, NLN, and tumor tissues.

RESULTS: Of 33045 lncRNAs, 1133 were differentially expressed in MLN compared with NLN, of which 260 were up-regulated and 873 down-regulated (≥ 2 fold-change). Five hundred and forty-five lncRNAs were differentially expressed in MLN compared with tumor tissues, of which 460 were up-regulated and 85 down-regulated (≥ 2 fold-change). Compared with NLN and cancer tissues, 14 lncRNAs were specifically up-regulated and 5 specifically down-regulated in MLN. AK307796, ENST00000425785, and AK021444 were confirmed to be specifically up-regulated in MLN and ENST00000465846 specifically down-regulated in MLN by qRT-PCR in 26 CRC patients.

CONCLUSION: The specifically expressed lncRNAs in MLN may exert a partial or key role in the progress of lymph nodes metastasis of CRC.

Keywords: Long noncoding RNAs; Colorectal cancer; Lymph nodes metastasis; Quantitative real-time polymerase chain reaction; MicroRNA

Core tip: Long noncoding RNAs (lncRNAs) have been reported to be aberrantly expressed in a variety of human cancers. However, no data are available regarding their functions in the lymph nodes metastasis of colorectal cancer (CRC). Our study is the first study to focus on lymph nodes metastasis associated lncRNAs in CRC by microarray. Obvious changes of lncRNAs expression profiles were observed in metastatic lymph node, normal lymph node, and tumor tissues of CRC. These changes of lncRNAs may serve as new diagnostic biomarkers and therapeutic targets for lymph node metastasis of CRC.