Circ_0000267 promotes gastric cancer progression via sponging MiR‐503‐5p and regulating HMGA2 expression

Abstract

Background: Circular RNAs (circRNAs) are a class of newly discovered RNAs that attach great importance to modulate gene expression and biological function.Nonetheless, in gastric cancer (GC), the expression and function of circRNA are much less explored. In this study, circ_0000267 expression in GC was investigated and the function and mechanism of circ_0000267 was probed. Materials and Methods: Quantitative real-time PCR (qRT-PCR) was employed to detect circ_0000267, miR-503-5p, and HMGA2 expression. Immunohistochemistry and western blot were adopted to detect HMGA2 and epithelial-mesenchymal transition (EMT)-related proteins (E-cadherin and N-cadherin) expression in GC tissues and cells, respectively. GC cell lines with circ_0000267 overexpressed and knocked down were constructed, and CCK-8 assay, BrdU assay, scratch healing assay, and transwell assay were employed to assess the effect of circ_0000267 on the proliferation and metastasis of GC cells. Besides, dual-luciferase reporter gene assay was adopted to verify the targeting relationship between circ_0000267 and miR-503-5p. Results: Circ_0000267 showed a significant upregulation in GC tissues and cell lines, and its high expression level was extremely linked to the increased tumor diameter and local lymph node metastasis. Circ_0000267 overexpression accelerated GC cell proliferation, metastasis, and EMT processes, while knocking down circ_0000267 led to the opposite effect. From the perspective of mechanism, circ_0000267 promoted the progression of GC through adsorbing miR-503-5p and upregulating HMGA2 expression. Conclusion: Circ_0000267 is an oncogenic circRNA that affects the progression of GC, which participates in promotion of GC proliferation, migration, invasion, and EMT via modulating the miR-503-5p/HMGA2 axis. K E Y W O R D Scirc_0000267, Gastric cancer, HMGA2, miR-503-5p 2 of 12 | XIAOPENG Et Al. F I G U R E 2 circ_0000267 promoted GC cell proliferation, movement, migration, and invasion. (a) circ_0000267 plasmid was transfected into MGC-803 cells, and circ_0000267 in SGC-7901 cells was knocked down with siRNA, and the transfection efficiency was examined by qRT-PCR. (b-d) The proliferation of GC cells was examined using the CCK-8 assay and the BrdU assay. (e, f) Scratch healing experiments were used to detect the movement of GC cells. (g) Transwell assay was used to detect GC cell migration and invasion. (h) Western blot was used to detect the expression of EMT-related marker molecules, including E-cadherin and N-cadherin.

Circ_0001175 Promotes Hepatocellular Carcinoma Cell Proliferation and Metastasis by Regulating miR-130a-5p

“…Circular RNAs (circRNAs) are closed-loop RNAs formed by reverse splicing of pre-mRNA. 8 It is reported that the dysregulation of circRNAs is significantly associated with the carcinogenesis and progression of liver cancer. [9][10][11][12] For example, circ_0000885 expression is upregulated in HCC and circ_0000885 enhances HCC cell proliferation.…”

lncRNA RAET1K Promotes the Progression of Acute Myeloid Leukemia by Targeting miR-503-5p/INPP4B Axis

“…Then, Starbase database was used to predict their interaction, and the prediction suggested that there was putative binding site between RAET1K and miR-503-5p. MiR-503-5p has been revealed to play essential roles in human diseases such as cervical cancer, 33 neuroblastoma, 34 gastric cancer, 35 and so on. These studies above suggested that miR-503-5p might also play important roles in AML.…”

MicroRNA‑503‑5p improves carotid artery stenosis by inhibiting the proliferation of vascular smooth muscle cells

“…The clinical value of miR-503-5p has been widely reported in previous studies. Circular RNA (Circrna) 0000267 promotes gastric cancer progression through sponging miR-503-5p and regulation of high-mobility group AT-hook 2 expression ( 29 ). Low expression of miR-503 in gastric cancer tissues and serum may be used as a diagnostic marker for gastric cancer ( 30 ).…”