Circ_0000808 promotes the development of non-small cell lung cancer by regulating glutamine metabolism via the miR-1827/SLC1A5 axis.

backgroundCircular RNA (circRNA) has been proved to be an important molecular target for cancer treatment. However, the function and molecular mechanism of circ_0000808 in non-small cell lung cancer (NSCLC) are still unclear.

methodsQuantitative real-time PCR was used to detect the expression of circ_0000808, miR-1827, and solute carrier family 1 member 5 (SLC1A5). Cell proliferation, apoptosis, migration, and invasion were measured by cell counting kit 8 assay, colony formation assay, EdU staining, flow cytometry, wound healing assay, and transwell assay. The protein expression was measured by Western blot analysis. Dual-luciferase reporter assay and RIP assay were used to investigate the interactions between miR-1827 and circ_0000808 or SLC1A5. Cell glutamine metabolism was assessed by determining glutamine uptake, glutamate production, and α-ketoglutarate production. Xenograft mouse model was used to assess the in vivo effects of circ_0000808.

resultsCirc_0000808 expression was upregulated in NSCLC tissues and cancer cells, and its silencing inhibited NSCLC cell proliferation, migration, and invasion and led to apoptosis. Further results confirmed that circ_0000808 interacted with miR-1827 to positively regulate SLC1A5. The rescue experiments showed that miR-1827 inhibitor reversed the suppressive effect of circ_0000808 knockdown on the malignant behaviors of NSCLC cells. Also, SLC1A5 overexpression abolished the inhibition effect of miR-1827 on NSCLC cell progression. In addition, circ_0000808/miR-1827/SLC1A5 axis positively regulated the glutamine metabolism process in NSCLC cells. Moreover, circ_0000808 knockdown reduced the NSCLC tumor growth in vivo.

conclusionIn summary, our data showed that circ_0000808 enhanced the progression of NSCLC by promoting glutamine metabolism through the miR-1827/SLC1A5 axis.