CBR3-AS1 Accelerates the Malignant Proliferation of Gestational Choriocarcinoma Cells by Stabilizing SETD4

BACKGROUND: Gestational choriocarcinoma (GC) is a rare malignant gestational trophoblastic tumor. Long noncoding RNA (lncRNA) CBR3 antisense RNA 1 (CBR3-AS1) has been reported to serve as a critical oncogene and facilitate tumor progression. Besides, we found that CBR3-AS1 is implicated in GC progression. MATERIALS AND METHODS: Gene and protein expression was detected via quantitative reverse transcription PCR (RT-qPCR) and western blot analyses, respectively. CCK-8 assay and colony formation assay were performed to assess cell proliferative abilities while flow cytometry analysis was applied for cell cycle and apoptosis. To analyze the specific mechanism among CBR3-AS1, SET domain containing 4 (SETD4), and polypyrimidine tract binding protein 1 (PTBP1), RNA binding protein immunoprecipitation (RIP), RNA pulldown, and mRNA stability assays were conducted. RESULTS: CBR3-AS1 was markedly upregulated in GC cells, and its downregulation suppressed cell proliferation, induced cell cycle arrest, but promoted cell apoptosis in GC. SETD4 was determined as the downstream mRNA of CBR3-AS1 and positively regulated by CBR3-AS1 in GC cells. Furthermore, CBR3-AS1 could interact with its RNA binding protein (RBP) PTBP1, thereby stabilizing SETD4 mRNA. Rescue assays verified that CBR3-AS1 facilitates GC cell malignant proliferation via SETD4. CONCLUSION: CBR3-AS1 accelerates the malignant proliferation of GC cells via stabilizing SETD4.