Long noncoding RNA NEAT1 promotes tumorigenesis in H. pylori gastric cancer by sponging miR-30a to regulate COX-2/BCL9 pathway.

Abstract

BACKGROUND:

Helicobacter pylori (H. pylori) is a carcinogenic factor for gastric cancer. Our previous study demonstrated that H. pylori decreased the expression of micro-RNA (miRNA)-30a to promote the tumorigenesis of gastric cancer. However, the upstream regulatory molecules of miR-30a are not well elucidated. In this study, we found the long non-coding RNA (lncRNA) nuclear paraspeckle assembly transcript 1 (NEAT1) may sponge miR-30a to regulate COX-2/BCL9 pathway.

METHODS:

The expression of NEAT1 was detected in gastric cancer tissues and tumor-adjacent tissues by fluorescence in situ hybridization (FISH) analysis and RT-qPCR. LncRNA-miRNA interaction networks were constructed using the RNAhybrid and starBase v.2.0. and then validated using a dual-luciferase reporter assay. The effects of NEAT1 dysregulation on the proliferative, migratory, and invasive abilities of H. pylori filtrate-infected gastric cancer cells were observed by cell counting kit-8 (CCK-8), colony formation, wound healing test, and transwell assays. Western blot and RT-qPCR were performed to detect protein and RNA expression. Immunohistochemistry (IHC) was carried out to analyze the localization and expression of COX-2 and BCL9.

RESULTS:

FISH and RT-qPCR demonstrated that the expression of NEAT1 was up-regulated in gastric cancer tissues, especially in H. pylori-infected gastric cancer tissues, and the expression of NEAT1 was negatively correlated with miR-30a (miR-30a-3p and miR-30a-5p). The upregulation of NEAT1 enhanced proliferation, migration, and invasion of H. pylori filtrate-infected gastric cancer cells, while the downregulation of NEAT1 decreased these abilities, and miR-30a could reverse the effect of NEAT1 on these abilities. The dual-luciferase reporter assay identified that NEAT1 directly targeted miR-30a (miR-30a-3p and miR-30a-5p). Because miR-30a (miR-30a-3p and miR-30a-5p) negatively regulates the expression of downstream COX-2 and BCL9, NEAT1 was identified to upregulate indirectly the expression of COX-2 and BCL9. IHC showed that the expression of COX-2 and BCL9 was increased in H. pylori gastric cancer tissues.

CONCLUSION:

The study demonstrated that lncRNA NEAT1 may act as a promoter of tumorigenesis in H. pylori gastric cancer, by sponging miR-30a (miR-30a-3p and miR-30a-5p) to regulate the COX-2/BCL9 pathway.

• Authors: Xiwu Rao, Xuan Liu, Ningning Liu, Yi Zhang, Zhaozhou Zhang, Lihong Zhou, Gang Han, Rong Cen, Nuolin Shi, Huirong Zhu, Hangjun Gong, Chen Huang, Qing Ji, Qi Li
• Journal: Helicobacter (Helicobacter) Vol. 26 Issue 6 Pg. e12847 (Dec 2021) ISSN: 1523-5378 [Electronic] England
• PMID: 34396632 (Publication Type: Journal Article)
• Copyright: © 2021 John Wiley & Sons Ltd.

Chemical References

• BCL9 protein, human
• MIRN30a microRNA, human
• MicroRNAs
• NEAT1 long non-coding RNA, human
• RNA, Long Noncoding
• Transcription Factors
• Cyclooxygenase 2

Topics

• Carcinogenesis (genetics)
• Cell Line, Tumor
• Cell Movement
• Cell Proliferation
• Cyclooxygenase 2 (genetics)
• Gene Expression Regulation, Neoplastic
• Helicobacter Infections (complications, genetics)
• Helicobacter pylori
• Humans
• In Situ Hybridization, Fluorescence
• MicroRNAs (genetics)
• RNA, Long Noncoding (genetics)
• Stomach Neoplasms (genetics, microbiology)
• Transcription Factors (genetics)