Published online Dec 21, 2019. doi: 10.3748/wjg.v25.i47.6823
Peer-review started: September 23, 2019
First decision: November 4, 2019
Revised: November 15, 2019
Accepted: November 29, 2019
Article in press: November 29, 2019
Published online: December 21, 2019
Gastric adenocarcinoma (GAC) mortality rates have remained relatively changed over the past 30 years, and it continues to be one of the leading causes of cancer-related death.
To search for novel miRNAs related to GAC prognosis and further investigate the effect of miR-96-5p on MGC-803 cells.
The miRNA expression profile data of GAC based on The Cancer Genome Atlas were obtained and used to screen differently expressed miRNAs (DEMs) and DEMs related to GAC prognosis. Then, the expression of DEMs related to GAC prognosis was identified in GAC tumor samples and adjacent normal samples by qRT-PCR. The target gene, ZDHHC5, of miR-96-5p was predicted using TargetScan, miRTarBase, and miRDB databases and confirmed by luciferase reporter assay. Furthermore, MGC-803 cells were transfected with inhibitor NC, miR-96-5p inhibitor, si-ZDHHC5, or miR-96-5p inhibitor + si-ZDHHC5, and then cell apoptosis was detected by flow cytometry. The expression of ZDHHC5, Bcl-2, and COX-2 was detected using western blotting.
A total of 299 DEMs and 35 DEMs related to GAC prognosis were screened based on The Cancer Genome Atlas. Then compared with adjacent normal samples, the levels of miR-96-5p, miR-222-5p, and miR-652-5p were remarkably increased, while miR-125-5p, miR-145-3p, and miR-379-3p levels were reduced in GAC tumor samples (P < 0.01), which were consistent with bioinformatics analysis. Furthermore, ZDHHC5 was defined as a direct target gene of miR-96-5p. miR-96-5p inhibition increased the number of apoptotic cells as well as promoted the expression of ZDHHC5, Bcl-2, and COX-2 in MGC-803 cells (P < 0.01). After ZDHHC5 inhibition, the number of apoptotic cells and the expression of ZDHHC5, Bcl-2, and COX-2 were reduced. The addition of an miR-96-5p inhibitor partly reversed these effects (P < 0.01).
Our findings identified six miRNAs related to GAC prognosis and suggested that downregulated miR-96-5p might induce cell apoptosis via upregulating ZDHHC5 expression in MGC-803 cells.
Core tip: Gastric adenocarcinoma (GAC) is the most common malignant tumor. It is important to further reveal novel diagnostic and therapeutic methods as well as the underlying molecular mechanism of GAC. This study aimed to search for novel miRNAs related to GAC prognosis. Six miRNAs related to prognosis, including miR-96-5p, miR-125-5p, miR-145-3p, miR-222-5p, miR-379-3p, and miR-652-5p, were identified in GAC samples. Furthermore, downregulated miR-96-5p markedly induced cell apoptosis through targeting ZDHHC5. Current findings provide a potential molecular mechanism of miR-96-5p in GAC.