Basic Study
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Aug 15, 2019; 11(8): 622-633
Published online Aug 15, 2019. doi: 10.4251/wjgo.v11.i8.622
shRNA-interfering LSD1 inhibits proliferation and invasion of gastric cancer cells via VEGF-C/PI3K/AKT signaling pathway
Hong-Ming Pan, Wei-Ya Lang, Li-Jie Yao, Yan Wang, Xiao-Ling Li
Hong-Ming Pan, Department of Biochemistry, Qiqihar Medical University, Qiqihar 161000, Heilongjiang Province, China
Wei-Ya Lang, Department of Histology and Embryology, Qiqihar Medical University, Qiqihar 161000, Heilongjiang Province, China
Li-Jie Yao, Yan Wang, Xiao-Ling Li, Department of Anatomy, Qiqihar Medical University, Qiqihar 161000, Heilongjiang Province, China
Author contributions: Pan HM, Lang WY, Yao LJ and Wang Y designed this work, collected and interpreted the data, and drafted the manuscript; Li XL designed this work, critically revised the manuscript, and performed overall supervision; all authors contributed to the final approval and accountability for the manuscript.
Supported by Doctoral Special Research Fund of Qiqihar Medical College, No. QY2016B-06.
Institutional review board statement: This study was reviewed and approved by the Qiqihar Medical University.
Conflict-of-interest statement: No conflict of interest exists.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Xiao-Ling Li, PhD, Associate Professor, Department of Anatomy, Qiqihar Medical University, No. 333 Bukui North Street, Jianhua District, Qiqihar 161006, Heilongjiang Province, China. lixiaoling0420@126.com
Telephone: +886-452-2663121
Received: May 16, 2019
Peer-review started: May 21, 2019
First decision: July 22, 2019
Revised: July 31, 2019
Accepted: August 3, 2019
Article in press: August 3,2019
Published online: August 15, 2019
Processing time: 91 Days and 22.4 Hours
Abstract
BACKGROUND

Histone Lysine Specific Demethylase 1 (LSD1) is the first histone demethylase to be discovered, which regulates various biological functions by making lysine of histone H3K4, H3K9 and non-histone substrates demethylated. Abnormal regulation of LSD1 is closely related to the occurrence and development of gastric cancer. The change of LSD1 expression level plays an important role in the proliferation and metastasis of gastric cancer cells. The study of its function and mechanism may provide a theoretical basis for early diagnosis and targeted therapy of gastric cancer.

AIM

To investigate the effect of downregulation of lysine-specific demethylase 1 (LSD1) expression on proliferation and invasion of gastric cancer cells and the possible regulatory mechanisms of the VEGF-C/PI3K/AKT signaling pathway.

METHODS

The LSD1-specific short hairpin RNA (shRNA) interference plasmid was transiently transfected, and expression of LSD1 was downregulated. The cell proliferation ability of LSD1 was observed by CCK-8 assay after downregulating expression of LSD1. Transwell invasion assay was used to observe the change of cell invasion ability after downregulating expression of LSD1. Expression of phosphorylated phosphoinositide 3-kinase (p-PI3K), PI3K, p-AKT, AKT, vascular endothelial growth factor receptor (VEGFR)-3, matrix metalloproteinase (MMP)-2 and MMP-9 in each group was detected by Western blotting.

RESULTS

The cell proliferation ability of transiently transfected LSD1-shRNA interference plasmid group was significantly lower than that of the control group (P < 0.05). Transwell invasion assay showed that the number of cells across the membrane of the LSD1-shRNA transfection group (238.451 ± 5.216) was significantly lower than that of the control group (49.268 ± 6.984) (P < 0.01). Western blotting showed that expression level of VEGF-C, p-PI3K, PI3K, p-AKT, AKT, VEGFR-3, MMP-2 and MMP-9 in the LSD1-shRNA group was significantly lower than that in the control group (P < 0.05).

CONCLUSION

Downregulation of LSD1 expression inhibits metastatic potential of gastric cancer cells, and VEGF-C-mediated activation of PI3K/AKT signaling pathway, which may be an important mechanism for inhibiting lymph node metastasis in gastric cancer cells.

Keywords: Gastric cancer; Lysine specific histone demethylase 1; Cell proliferation; Cell invasion; VEGF-C/PI3K/AKT signaling pathway

Core tip: The abnormal regulation of Lysine Specific Demethylase 1 (LSD1) is closely related to the occurrence and development of various cancers, such as gastric cancer. LSD1 is highly expressed in gastric cancer tissues, and the change in LSD1 expression level plays an important role in the proliferation and metastasis of gastric cancer cells. The VEGF-C/PI3K/AKT signaling pathway plays an important role in lymphangiogenesis and metastasis of gastric cancer. Therefore, this study investigated downregulation of LSD1 expression in order to observe the changes in gastric cancer cell proliferation and invasion, and further explored the role of the VEGF-C/PI3K/AKT signaling pathway. This study explores the role and mechanism of LSD1 in inhibiting gastric cancer cell metastasis from the perspective of epigenetics, providing a basis for early clinical diagnosis of gastric cancer metastasis.