15-Lipoxygenase-2 (15-LOX-2) and 15(S)-hydroxyeicosatetraenoic acid (15(S)-HETE) have been considered as latent mediators of diverse biological processes including cancer. However, their functions in lung adenocarcinoma (LAC) are unclear. In this study, we aimed to determine whether 15-LOX-2/15(S)-HETE is involved in the proliferation and migration of A549 cells and to identify the signaling pathways that participate in this process. We used immunohistochemistry to identify the expression levels of 15-LOX-2 in lung cancer tissue samples. The effects of 15(S)-HETE on the proliferation and migration of A549 cells under hypoxic conditions were assessed by cell viability assays, immunofluorescence, western blotting, scratch wound assays and transwell assays. We found that the expression of 15-LOX-2 was significantly up-regulated in LAC tissue samples compared with adjacent normal tissue samples. The content of 15(S)-HETE in A549 cells was increased under hypoxic conditions. Moreover, 15(S)-HETE could stimulate the expression of PCNA, cyclin A and cyclin D. In addition, siRNA of 15-LOX-2 inhibited the proliferation and migration of A549 cells in vitro. Our data also provide novel evidence demonstrating that the STAT3 pathway participates in the 15(S)-HETE-induced proliferation and migration of A549 cells. This study may provide a greater understanding of LAC metastasis and shed new light on the mechanisms by which the 15(S)-HETE/STAT3 pathway is related to this disease.
Keywords: 15(S)-Hydroxyeicosatetraenoic acid; 15-Lipoxygenase-2; Hypoxia; Lung adenocarcinoma; Proliferation; Signal transducer and activator of transcription 3.
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