Published online Jul 21, 2023. doi: 10.3748/wjg.v29.i27.4317
Peer-review started: March 28, 2023
First decision: April 27, 2023
Revised: May 10, 2023
Accepted: June 2, 2023
Article in press: June 2, 2023
Published online: July 21, 2023
Processing time: 106 Days and 22.9 Hours
Gastric cancer(GC) is among the most severe gastrointestinal malignancies, with high morbidity and mortality. In recent years, increasing evidence has shown that natural products can prevent and inhibit the development of GC by regulating miRNA and other genes, showing great therapeutic potential.
Targeting miRNA and other genes in GC with natural drugs is a promising strategy, which provides a valid reference to further elucidate the molecular mechanism of natural products in the treatment of GC.
The purpose of this study was to investigate the molecular mechanism of 18β-glycyrrhetinic acid (18β-GRA) regulating the miR-328-3p/ signal transducer and activator of transcription 3 (STAT3) signaling pathway, promoting the autophagy flow of GC cells and inhibiting cell proliferation.
The differentially expressed miRNAs were screened by full transcriptomic analysis. The cells were transfected with lentivirus, and the functional indices of the cells were determined by Cell Counting Kit-8, clone forming method, and flow cytometry. The effect of overexpression of miR-328-3p on the tumorigenicity of GC cells was detected in the transplanted tumor model of nude mice. Hematoxylin-eosin staining and immunohistochemistry were used to observe tumor tissue morphology and detect protein expression, respectively. Bioinformatics analysis was performed using TransmiR, STRING, and miRWalk databases. Real-time quantitative polymerase chain reaction and western blot were used to detect mRNA and protein expression levels. Dual luciferase reporter system was used to verify the targeting relationship between genes. The autophagy flow of monomeric red fluorescent protein- green fluorescent protein - light chain 3 adenovirus double-labeled infected cells was observed under confocal laser microscopy.
18β-GRA could upregulate the expression of miR-328-3p in AGS cells. Overexpression of miR-328-3p inhibited the cell proliferation and colony formation ability, arrested the cell cycle, promoted apoptosis, inhibited the growth of subcutaneous tumors, and led to GC tissue cell necrosis increase. miR-328-3p can target and regulate STAT3. 18β-GRA intervention in GC cells and overexpression of miR-328-3p could downregulate the expression level of STAT3 mRNA. Compared with the vector group, the expression level of LC3 II was downregulated in the overexpressed miR-328-3p + bafilomycin A1 (Baf A1) group and upregulated in the overexpressed miR-328-3p + Baf A1 group. The number of yellow spots and separate red signals in the 18β-GRA group were significantly increased compared with the negative control group, and the number of yellow spots in the 18β-GRA + Baf A1 group was significantly increased compared with the Baf A1 group.
18β-GRA promotes GC cells' autophagosome synthesis and inhibits cell proliferation by regulating the miR-328-3p/STAT3 signaling pathway.
MiR-328-3p/STAT3 can be regulated by 18β-GRA and can be used as an effective drug target for the prevention and treatment of GC, thus providing a scientific basis for the clinical treatment of GC.