Circ_0007624 suppresses the development of esophageal squamous cell carcinoma via targeting miR-224-5p/CPEB3 to inactivate the EGFR/PI3K/AKT signaling.

Circular RNAs (circRNAs) have been confirmed to be involved in the regulation of esophageal squamous cell carcinoma (ESCC) progression. According to GEO datasets (GSE112496 and GSE150476), we identified that circ_0007624 was abnormally down-regulated in ESCC. However, there is still no reports regarding the function and mechanism of circ_0007624 in ESCC development. Here, we found that circ_0007624 was significantly underexpressed in ESCC tissues, and low expression of circ_0007624 was indicative of a poor prognosis. Overexpressing circ_0007624 or silencing miR-224-5p suppressed cell proliferation, metastasis, epithelial-mesenchymal transition (EMT), and promoted apoptosis in vitro. Also, circ_0007624 up-regulation slowed ESCC tumor growth in vivo. Mechanistically, circ_0007624 could serve as a competing endogenous RNA (ceRNA) by sponging miR-224-5p to antagonize its inhibitory effect on the target cytoplasmic polyadenylation element binding protein 3 (CPEB3). Rescue experiments showed that the anti-cancer properity role of circ_0007624 in ESCC is partly reversed by the restoration of miR-224-5p or down-regulation of CPEB3. Furthermore, EGFR/PI3K/AKT pathway was involved in the regulation of circ_0007624/miR-224-5p/CPEB3 axis in ESCC. Together, our findings demonstrate for the first time that circ_0007624/miR-224-5p/CPEB3 suppresses ESCC progression by inactivating EGFR/PI3K/AKT signaling, providing a basis for developing circ_0007624-targeted therapies for ESCC patients.

Cheng J ，Ma H ，Yan M ，Zhang Z ，Xing W ... -  《-》

Hsa_circ_0023984 Regulates Cell Proliferation, Migration, and Invasion in Esophageal Squamous Cancer via Regulating miR-1294/PI3K/Akt/c-Myc Pathway.

Circular RNAs (circRNAs) exert an essential function in the tumorigenesis and progression of esophageal squamous cancer (ESCC). Nonetheless, the role and potential mechanism of circ_0023984 in ESCC are blurred. circRNA expression profile data from Gene Expression Omnibus (GEO) database was applied to analyze circRNAs that were differentially expressed between ESCC tissues and paracancerous tissues. Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to analyze circ_0023984 expression and miR-1294 expression in ESCC tissues and cells. Then a series of functional experiments were executed to validate the role of circ_0023984 and miR-1294 in modulating the proliferation, migration, invasion, and cell cycle progression of ESCC cells. Luciferase reporter experiment was performed to confirm the targeting relationship between circ_0023984 and miR-1294. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were carried out with DAVID database. Western blot assay was utilized to detect phosphorylated-Akt (p-Akt) expression and c-Myc expression. circ_0023984 was remarkably upmodulated in ESCC tumor tissues and cell lines. circ_0023984 overexpression was correlated with advanced clinical stage and lymph node metastasis of ESCC patients. circ_0023984 overexpression remarkably enhanced ESCC cell proliferation, migration, invasion, and cell cycle progression, while knockdown of circ_0023984 showed the opposite effect. circ_0023984 was the molecular sponge of miR-1294. miR-1294 could significantly inhibit ESCC cell proliferation, migration, invasion, and induce cell cycle arrest at G0/G1 phase. circ_0023984 affected ESCC progression through regulating miR-1294 expression. The target genes of miR-1294 were associated with cell cycle arrest and PI3K-Akt signaling pathway. circ_0023984 upregulated the expression of p-Akt and c-Myc by repressing miR-1294. circ_0023984 facilitates the malignant biological behaviors of ESCC cells through inhibiting miR-1294 and activating PI3K/Akt/c-myc pathway.

Liang W ，Wang C ，Wang J ，Zhang M ... -  《-》

Circular RNA hsa_circ_0000654 promotes esophageal squamous cell carcinoma progression by regulating the miR-149-5p/IL-6/STAT3 pathway.

Circular RNAs (circRNAs) are novel noncoding RNAs (ncRNAs) with covalently closed-loop structures that play an essential regulatory role in diverse malignancies, including esophageal squamous cell cancer (ESCC). Circ_0000654 expression in ESCC and its mechanism of action remains unclear. Real-time PCR (RT-PCR) was employed to detect circ_0000654 and miR-149-5p expression in ESCC tissues. Circ_0000654 and miR-149-5p expression in ESCC cells was selectively regulated. Furthermore, interleukin 6 (IL-6) and signal transducer and activator of transcription 3 (STAT3) expression in cells was detected by RT-PCR and western blot analysis, while CCK8, BrdU, flow cytometry, and transwell assays were used to monitor cell proliferation, apoptosis, migration and invasion, respectively. The dual-luciferase reporter assay and RIP assay were used to verify the targeting relationship between circ_0000654 and miR-149-5p, miR-149-5p and IL-6. The function of circ_0000654 on ESCC cell proliferation and metastasis in vivo was examined using a subcutaneous xenograft model and a tail intravenous injection model in nude mice. Circ_0000654 was significantly upregulated in ESCC tissues and cell lines, and its high expression was remarkably associated with an increased T stage and local lymph node metastasis in ESCC patients. Circ_0000654 overexpression and knockdown experiments revealed that circ_0000654 regulated ESCC cell proliferation, migration, invasion, and apoptosis in vitro. Circ_0000654 was identified as a sponge of miR-149-5p and facilitated ESCC progression by indirectly activating the IL-6/STAT3 signaling pathway. Additionally, knocking down circ_0000654 strikingly repressed ESCC growth and metastasis in vivo. In summary, circ_0000654 functions as an oncogenic circRNA in ESCC and accelerates ESCC progression via adsorbing miR-149-5p and activating the IL-6/STAT3 signaling pathway.

Xu Z ，Tie X ，Li N ，Yi Z ，Shen F ，Zhang Y ... -  《-》

Circular RNA hsa_circ_0000277 sequesters miR-4766-5p to upregulate LAMA1 and promote esophageal carcinoma progression.

Zhou PL ，Wu Z ，Zhang W ，Xu M ，Ren J ，Zhang Q ，Sun Z ，Han X ... -  《Cell Death & Disease》

Circ_FNDC3B Promotes Cell Proliferation and Metastasis in Esophageal Squamous Cell Carcinoma via Regulating MAPK1 by Binding to miR-136-5p.

Li Y ，Ma L ，Li P 《-》