ObjectiveTo investigate the effects of excessive activation of the Specific protein 1 （Sp1）-MicroRNA-582-3p （miR-582-3p）-cyclin-dependent kinase inhibitor （p27） axis on the cell cycle and proliferation of A549 lung adenocarcinoma cells at the cellular level， thereby investigating the possible mechanisms by which Astragali Radix and Hedyotis diffusa（A-H） regulate the axis to inhibit A549 cells proliferation. MethodsLentiviral plasmid transfection technology was used to obtain four stable A549 transgenic cell lines： shRNA-Sp1+LV-miR-582-3p mimic， shRNA-Sp1+LV-mNC， shRNA-NC+LV-miR-582-3p mimic， and shRNA-NC+LV-mNC. Real-time PCR was used to detect the effect of Sp1 on miR-582-3p expression in A549 lung adenocarcinoma cells. CCK-8 and colony formation assay were used to detect the effect of Sp1 on cell proliferation through miR-582-3p， while flow cytometry was used to detect the effect of Sp1 on cell cycle via miR-582-3p. Western blot was used to detect the effect of Sp1 on cyclin in A549 cells through miR-582-3p. CCK-8 was employed to detect the effects of different concentrations （5%， 10%， 20%， 40%， 80%） of A-H on A549 cell viability， and the optimal concentration was selected for subsequent mechanism exploration. Stable transgenic strains oe-Sp1 and control oe-Vector were constructed using the above-mentioned transfection techniques. Real-time PCR was then used to investigate the effect of A-H on miR-582-3p expression in A549 cells， while Western blot was employed to detect the effect of A-H on Sp1 and p27 expression in A549 lung adenocarcinoma cells. ResultsCompared with the shRNA-NC+LV-mNC group， the expression of miR-582-3p was significantly inhibited in the shRNA-Sp1+LV-mNC group （P<0.01）. Compared with the shRNA-Sp1+LV-mNC group， the shRNA-Sp1+LV-miR-582-3p mimic group significantly reversed miR-582-3p expression （P<0.01）， indicating that Sp1 has a significant regulatory effect on miR-582-3p. Compared with the shRNA-Sp1+LV-mNC group， the shRNA-Sp1+LV-miR-582-3p mimic group significantly reversed cell proliferation （P<0.01）， suggesting that miR-582-3p can partially reverse the proliferative effect of Sp1 on A549 lung adenocarcinoma. Compared with the shRNA-Sp1+LV-mNC group， the shRNA-Sp1+LV-miR-582-3p mimic group showed a significant decrease in G₀/G₁ proportions， while the G₂/M and S phase proportions increased significantly （P<0.01）， indicating that miR-582-3p can partially reverse the effect of Sp1 on the A549 cell cycle. Compared with the shRNA-Sp1+LV-mNC group， the shRNA-Sp1+LV-miR-582-3p mimic group significantly reversed the expression of various proteins with the decrease of p27 and the increase of Cyclin D₁， CDK4， Cyclin E， CDK2， p-Rb， and E2F3 （P<0.01）， indicating that miR-582-3p can partially reverse the effect of Sp1 on the cell cycle of A549 lung adenocarcinoma. Compared with the blank group， the serum containing A-H significantly inhibited A549 cell viability in a concentration-dependent manner. Therefore， 10% A-H was selected for intervention of subsequent mechanism experiments. Compared with A-H+oe-Vector， A-H+oe-Sp1 significantly reversed the downregulation of Sp1， miR-582-3p， and the upregulation of p27 （P<0.01）. This suggests that Sp1 can partially reverse the effects of A-H on miR-582-3p and p27 levels in A549 lung adenocarcinoma cells. ConclusionOveractivation of the Sp1-miR-582-3p-p27 axis significantly promotes the proliferation of A549 lung adenocarcinoma cells， and the potential mechanism of the inhibitory effect of A-H on the proliferation of A549 cells may be related to its inhibition on the overactivation of the Sp1-miR-582-3p-p27 axis.