ANXA8 Regulates Proliferation of Human Non-Small Lung Cancer Cells A549 via EGFR-AKT-mTOR Signaling Pathway

Annexin A8 (ANXA8) is a member of the annexin family, which had been reported to regulate multiple cancer cellular processes including proliferation, metastasis and inflammation. However, the specific role of ANXA8 in lung cancer cell biology remains unknown. Our previous transcriptome study revealed that ANXA8 mRNA was downregulated in curcumin analog (MHMD)-treated human non-small lung cancer cells (A549 cell line). Here, we continued to study the ANXA8 expression in A549 cells using reverse transcription-quantitative PCR and Western blotting, compared with that in human normal bronchial epithelium cells (BE-AS-2B cell line). Overexpression of ANXA8 via transfection of pEGFP-ANXA8 recombinant vector contributed to the proliferation and migration of A549 cells. Moreover, the cell cycle protein cyclin E1 was upregulated in ANXA8-transfected A549 cells. Knockdown of ANXA8 using an RNA interference technique decreased A549 cell viability and restrained their migration in vitro. The expression levels of multiple cellular factors, including EGFR, PI3K, Akt, mTOR, p70S6K and 4EBP1, in the epidermal growth factor receptor (EGFR) signaling pathway were also altered by ANXA8 knockdown or overexpression in A549 cells, which confirmed the activation of the EGFR/Akt/mTOR signaling pathway by ANXA8. The present results provided evidence to support further investigation of the functional identification of ANXA8 in lung cancer cells in the future.