Circular RNA hsa_circ_0002483 promotes growth and invasion of lung adenocarcinoma by sponging miR-125a-3p

Prognostic significance of LINC01132 in lung cancer and its regulatory role in tumor progression

BACKGROUND

The application of long non-coding RNAs (lncRNAs) in cancer has been the focus of research in recent years. This study aimed to discuss the expression and functional mechanism of lncRNA LINC01132 (LINC01132) in lung cancer and explore its prognostic significance in tumors.

METHODS

The expression of LINC01132 in lung cancer patients was verified using GSE98929 screening and real-time quantitative polymerase chain reaction (RT-qPCR) detection. The prognostic potential of LINC01132 was evaluated by performing the chi-square analysis of clinical indicators, Kaplan-Meier analysis, and Cox proportional hazard model. Cell Counting Kit-8 (CCK-8), flow cytometry, and Transwell assay were used to characterize the biological functions of the lung cancer cells. The targeting relationship between LINC01132 and microRNA-125a-3p (miR-125a-3p), miR-125a-3p and SMAD2 was predicted by bioinformatics and verified by luciferase activity assay.

RESULTS

LINC01132 was upregulated in lung cancer tissues and cells, which was an independent risk factor for survival and prognostic outcomes of lung cancer patients. Silencing LINC01132 suppressed the proliferation and migration of lung cancer cells and accelerated cell death. The target of LINC01132 was miR-125a-3p, and miR-125a-3p inhibitor could eliminate the inhibitory effect of LINC01132 knockdown on the cells. Additionally, SMAD2 is a downstream target of miR-125a-3p, and knockdown of SMAD2 reversed the effects of miR-125a-3p inhibitor on cell migration and invasion.

CONCLUSION

LINC01132 may regulate the progression of lung cancer by targeting the miR-125a-3p /SMAD2 axis and serve as a prognostic biomarker for lung cancer.

Landscape of circular RNAs in different types of lung cancer and an emerging role in therapeutic resistance (Review)

Lung cancer is one of the most common malignant tumor types and the leading cause of cancer‑associated death worldwide. Different types of lung cancer exhibit differences in terms of pathophysiology and pathogenesis, and also treatment and prognosis. Accumulating evidence has indicated that circular RNAs (circRNAs) are abnormally expressed among different types of lung cancer and confer important biological functions in progression and prognosis. However, studies comparing different circRNAs in lung cancer subtypes are scarce. Furthermore, circRNAs have an important role in drug resistance and are related to clinicopathological features in lung cancer. Summaries of the association of circRNAs with drug resistance are also scarce in the literature. The present study outlined the biological functions of circRNAs and focused on discriminating differential circRNA patterns and mechanisms in three different types of lung cancer. The emerging roles of circRNAs in the resistance to chemotherapy, targeted therapy, radiotherapy and immunotherapy were also highlighted. Understanding these aspects of circRNAs sheds light on novel physiological and pathophysiological processes of lung cancer and suggests the application of circRNAs as biomarkers for diagnosis and prognosis, as well as therapeutic resistance.

CircPTK2 promotes cell viability, cell cycle process, and glycolysis and inhibits cell apoptosis in acute myeloid leukemia by regulating miR-582-3p/ALG3 axis

BACKGROUND

Circular RNA (circRNA) regulates the pathogenesis of acute myeloid leukemia (AML). However, the mechanism of circRNA protein tyrosine kinase 2 (circPTK2) in AML remains unclear.

METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) assay was adopted for circPTK2, miR-582-3p and alpha-1,3-mannosyltransferase (ALG3) mRNA levels. 3-(4, 5-Dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay, and 5'-ethynyl-2'-deoxyuridine (EdU) assay were conducted for cell proliferation. Flow cytometry analysis was employed for cell apoptosis and cell cycle process. The glycolysis level was estimated by specific commercial kits. Western blot assay was utilized for protein levels. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were performed to verify the interaction between miR-582-3p and circPTK2 or ALG3.

RESULTS

CircPTK2 level was enhanced in AML peripheral blood samples and cells. CircPTK2 knockdown restrained AML cell proliferation and glycolysis and promoted cell apoptosis and cell cycle arrest. Mechanically, circPTK2 functioned as the sponge for miR-582-3p to positively ALG3 expression in AML cells. Moreover, miR-582-3p inhibition ameliorated the impacts of circPTK2 knockdown on AML cell processes. MiR-582-3p overexpression regulated cell phenotypes by targeting ALG3.

CONCLUSION

CircPTK2 contributed to AML cell malignant behaviors by modulation of miR-582-3p/ALG3 axis, which might provide a potential target for AML therapy.