Circular RNA hsa_circ_0102231 sponges miR-145 to promote non-small cell lung cancer cell proliferation by up-regulating the expression of RBBP4.

Circular RNAs (circRNAs) are important regulators in various cancers. Previous studies have found that hsa_circ_0102231 is an oncogene in lung adenocarcinoma. Here, we investigated its mechanism in the development of non-small cell lung cancer (NSCLC). We detected the levels of hsa_circ_0102231 in five NSCLC cell lines and one normal bronchial epithelium cell line. The interaction between hsa_circ_0102231 and miR-145 was predicted and confirmed by pull-down and luciferase assays. The nuclear mass separation assay and fluorescence in situ hybridization were used to detect the distribution of hsa_circ_0102231. Cell Counting Kit-8 and Transwell assays were used to assess the cell proliferative and invasive ability. Western blot and RT-qPCR, respectively, detected the protein and mRNA levels of RBBP4. The RBBP4 promoter activity was detected with a luciferase assay. We found that hsa_circ_0102231 level was higher in NSCLC cells. hsa_circ_0102231 is mainly localized to the cytoplasm. hsa_circ_0102231 promotes NSCLC cell proliferation and invasion by sponge for miR-145. miR-145 significantly decreases the RBBP4 promoter activity, and its mRNA and protein levels. RBBP4 is an oncogene to promote proliferation and invasion ability. Our findings suggest that hsa_circ_0102231 promotes proliferation and invasion by mediating the miR-145/RBBP4 axis in NSCLC, indicating that it might be a potential target for NSCLC treatment.