RESUMO
CircRNAs have been identified play a key role in various different types of cancer. However, their role in lung adenocarcinoma remains unclear. In this study, we explored the specific circular transcriptome and characterized the circRNA expression profiles of five paired lung adenocarcinoma (LAC) tissues relative to adjacent normal tissues from LAC patients using next-generation sequencing (NGS). To illuminate circRNAs function, their gene targets were initially predicted before using, Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses to further analyse the associated significant cell signalling pathways and functions. The potential interactions between circRNA-miRNA-mRNA were also investigated. Additionally, qRT-PCR assay, Western blot and Immunohistochemistry were performed to validate the differential expression of circRNA, microRNA and mRNA in the LAC group in comparison to the control group. Two-hundred-eighty-five dysregulated circular transcripts were found in LAC tissues, among which 102 and 183 were either up or down regulated, respectively. Our biological analysis suggested that the host genes of differentially expressed circRNAs targeted to cancer-related processes and mechanisms. The interaction maps of the circRNA-miRNA-target gene were constructed using Cytoscope. In further study, hsa_circ_0002360 was found to be the most significantly overexpressed circRNA in LAC tissues by interacting with miRNA and its corresponding mRNA. Our results showed that hsa_circ_0002360 was aberrantly and abundantly expressed and implicated in the development of LAC, suggesting a valuable therapeutic target for LAC treatment.
RESUMO
Objective The relationship between circular RNAs (circRNA) and lung adenocarcinoma (LAC) remains to be further explored. This study aimed to investigate the expression of Hsa_circ_0002360 in LAC and its value in the clinical diagnosis and treatment of the malignancy. Methods This study included 50 cases of LAC treated in our hospital from May 2018 to June 2019 and another 50 healthy subjects as normal controls. We determined the expression of Hsa_circ_0002360 in the LAC cells by qRT⁃PCR. We cultured human LAC cell lines A549, H1299 and H1975 and human bronchial mucosal epithelial cell line BEAS-2B, inoculated the A549 and H1975 LAC cells in the 6-well plate, with 3 wells for si-circRNAs and the other 3 for negative controls (si-NC), followed by cell transfection experiment. Using the CCK8, colony formation and wound healing assays, we detected the effects of Hsa_circ_0002360 on the activity, proliferation, invasiveness and metastasis of the A549 and H1975 cells. Results The expression of Hsa_circ_0002360 was significantly higher in the LAC tissue than in the adjacent tissue (2.84 ± 0.12 vs 1.46 ± 0.08, P < 0.01), and so was it in the serum of the LAC patients than in the normal controls (2.59 ± 0.17 vs 1.21 ± 0.11, P < 0.01), but remarkably lower in the serum of the patients after than before surgery (1.58 ± 0.09 vs 2.65 ± 0.13, P < 0.01). Besides, its expression was significantly increased in the LAC A549, H1299 and H1975 cell lines compared with that in the BEAS-2B cells (P < 0.05). In comparison with the si-NC group, the si-circRNA group showed significant decreases in the rates of colony formation ([65.66± 4.93]% vs [38.33 ± 1.69]%, P < 0.01) and migration of the cells ([54.66±4.10]% vs [13.50 ± 3.34]%, P < 0.01) and in the count of H1975 cells as well (P < 0.01). Conclusion Hsa_circ_0002360 can be used as a biomarker for the early diagnosis and treatment of lung adenocarcinoma.
