Acacetin inhibited non-small-cell lung cancer (NSCLC) cell growth via upregulating miR-34a in vitro and in vivo

Abstract

Acacetin, one of the flavonoid compounds, is a natural product found in various plants, including Silver birch, and Damiana. Previous studies showed that acacetin has anti-cancer effects on many kinds of cancer cells, however, the role of and the mechanisms of actions of acacetin on non-small cell lung cancer (NSCLC) cells is still not fully understood. Herein, we found that, in vitro, acacetin inhibited the proliferation, invasion, and migration of NSCLC cells, A549 and H460, in a dose-dependent manner. Meanwhile, flow cytometry assay results showed that acacetin induced G2/M phase cell cycle arrest, and apoptosis of NSCLC cells. In vivo, acacetin suppressed tumor formation of A549-xenografted nude mice model with no obvious toxicities. Western blotting results showed that the protein levels of cell cycle-related proteins cyclin B1, cyclin D, and anti-apoptotic protein Bcl-2 had decreased, while the apoptosis-related protein Bak had increased both in NSCLC cells and in A549-xenografted tumor tissues. For investigating the molecular mechanism behind the biological effects of acacetin on NSCLC, we found that acacetin induced the expression levels of tumor suppressor p53 both in vitro and in vivo. MicroRNA, miR-34a, the direct target of p53, has been shown anti-NSCLC proliferation effects by suppressing the expression of its target gene programmed death ligand 1 (PD-L1). We found that acacetin upregulated the expression levels of miR-34a, and downregulated the expression levels of PD-L1 of NSCLC cells in vitro and of tumors in vivo. In vitro, knockdown p53 expression by siRNAs reversed the induction effects of acacetin on miR34a expression and abolished the inhibitory activity of acacetin on NSCLC cell proliferation. Furthermore, using agomir and antagomir to overexpress and suppress the expression miR-34a in NSCLC cells was also examined. We found that miR-34a agomir showed similar effects as acacetin on A549 cells, while miR-34a antagomir could partially or completely reverse acacetin’s effects on A549 cells. In vivo, intratumor injection of miR-34a antagomir could drastically suppress the anti-tumor formation effects of acacetin in A549-xenografted nude mice. Overall, our results showed that acacetin inhibits cell proliferation and induces cell apoptosis of NSCLC cells by regulating miR-34a.

PDL1 targeting by miR-138-5p amplifies anti-tumor immunity and Jurkat cells survival in non-small cell lung cancer

“…Some previous studies have shown that miR-138-5p plays a role in inhibiting proliferation, migration, and metastasis and inducing apoptosis in various cancers, including gastric, glioma, colorectal, and lung cancer 56 – 59 . However, most studies on NSCLC have focused on the A549 cell line 60 , 61 , so we designed an experiment to compare the behavior of A549 and Calu6 cell lines under the effect of miR-138-5p. Our study involved experiments to validate the impact of miR-138-5p on PDL1 expression, cell cycle, and apoptosis in adenocarcinoma cell lines, specifically A549 and Calu6.…”

Impact of Long-Lasting Environmental Factors on Regulation Mediated by the miR-34 Family

“…Research is still ongoing to improve the accessibility of miR-34 family members in translational research and clinical practice in respect to the treatment of breast cancer [41], colon cancer [42], lung cancer [43], oral cancer [44], oesophageal cancer [45] and some others (reviewed in [46]).…”