RETRACTED ARTICLE: Circular RNA hsa_circ_0001829 promotes gastric cancer progression through miR-155-5p/SMAD2 axis

Abstract

Background Accumulating evidences have shown that circular RNAs (circRNAs) play important roles in regulating the pathogenesis of cancer. However, the role of circRNAs in gastric cancer (GC) remains largely unclear. Methods In this study, we identified a novel upregulated circRNA, hsa_circ_0001829, in chemically induced malignant transformed human gastric epithelial cells using RNA-seq. Subsequent qRT-PCR and ISH assays were performed to detect the expression level of hsa_circ_0001829 in GC cell lines and tissues. Functional roles of hsa_circ_0001829 in GC were then explored by loss- and gain-of- function assays. Bioinformatic prediction and luciferase assay were used to investigate potential mechanisms of hsa_circ_0001829. Finally, the mice xenograft and metastasis models were constructed to assess the function of hsa_circ_0001829 in vivo. Results We found that hsa_circ_0001829 was significantly upregulated in GC tissues and cell lines. Loss- and gain-of- function assays showed that hsa_circ_0001829 promotes GC cells proliferation, migration and invasion, and the affected cell cycle progression and apoptosis rates may account for the effect of hsa_circ_0001829 on GC proliferation. In addition, bioinformatic prediction and luciferase assay showed that hsa_circ_0001829 acts as a molecular sponge for miR-155-5p and that SMAD2 was a target gene of miR-155-5p; moreover, hsa_circ_0001829 sponges miR-155-5p to regulate SMAD2 expression and hsa_circ_0001829 promotes GC progression through the miR-155-5p–SMAD2 pathway. Finally, suppression of hsa_circ_0001829 expression inhibited tumor growth and aggressiveness in vivo. Conclusion Taken together, our findings firstly demonstrated a novel oncogenic role of hsa_circ_0001829 in GC progression through miR-155-5p–SMAD2 axis, and our study may offer novel biomarkers and therapeutic targets for GC.

Circular RNA hsa_circ_0110389 promotes gastric cancer progression through upregulating SORT1 via sponging miR-127-5p and miR-136-5p

“…Hsa_circ_0110389 is up-regulated in GC tissues and cells, and high hsa_circ_0110389 expression associates with advanced stages of GC and predicts poor prognosis RNA-seq analysis between malignant-transformed human gastric epithelial cells (GES-1-T cells) induced by MNNG and NC cells (GES-1-N cells) was conducted in our previous study [17,18], and the heat map expression results showed that hsa_circ_0110389, accession id according to the annotation of circBase (http://www.circbase.org/), was highly up-regulated in GES-1-T cells (Fig. 1A).…”

“…CircRNAs play as ceRNAs to regulate target gene expression through miRNAs [29,30]. For example, circPGR was recently found to function as a ceRNA to promote estrogen receptorpositive breast cancer cell growth [31]; our recent study found that hsa_circ_0001829 functions as an oncogene in GC and exerts its effects via miR-155-5p/SMAD2 axis [18]. In current study, results of knockdown and overexpression assays revealed that hsa_circ_0110389 regulates GC cells proliferation, migration and invasion in vitro, and animal studies showed that hsa_circ_0110389 silencing inhibited tumor growth in vivo.…”

“…The absorbence was measured at 450 nm using Universal Microplate Spectrophotometer (Bio-Tek Instruments, Inc., Winooski, VT, USA). For EdU incorporation assay, GC cell proliferation ability was analyzed using EdU cell proliferation kit (Ribo, Guangzhou, China) according the manufacturer's protocol as we previously described [18].…”

“…For example, Liu et al recently demonstrated that circDLC1 was downregulated in hepatocellular carcinoma (HCC) tissues and inhibits HCC progression via interaction with RNAbinding protein HuR [15]; Zhang et al previously found that an endogenous circRNA is decreased in glioblastoma and suppresses oncogenic transcriptional elongation through encoding peptides [16]. In the context of GC, although our previous studies have revealed that hsa_circ_0001829 and hsa_circ_006100 participated in the MNNG-induced GC progression [17,18], the functions and mechanisms of circRNAs on environmental carcinogen-related gastric tumorigenesis remain poorly elucidated.…”

The role of circular RNA circ_0008285 in gestational diabetes mellitus by regulating the biological functions of trophoblasts

“…RNase R was purchased from Geneseed Biotech Co., Ltd. (Guangzhou, China). RNase R treatment was performed as described in a previous study [ 26 ]. In brief, total RNA (2 μg) was incubated with RNase R (3 U/μg) for 10 min at 37 °C.…”