IL-13 is a proinflammatory cytokine associated with multiple pathological conditions and the promotion of metastasis in lung cancer. Previous studies have demonstrated that IL-13 and YY1 are associated with PI3K/AKT signaling. In addition, miR-29a has been found to play a critical role in cell invasion in lung cancer. However, the molecular mechanism of miR-29a underlying its involvement in IL-13-induced lung cancer cell invasion remains largely unknown. In the present study, we aimed to investigate the role of miR-29a in cell invasion mediated by IL-13 in lung cancer. By using MTT and wound-scratch assays, we assessed cell proliferation and migration induced by IL-13, and identified activation of the PI3K/AKT/YY1 pathway. Inhibition of PI3K/AKT by LY294002 downregulated IL-13-induced YY1 expression. Furthermore, we found that miR-29a directly targets YY1 and suppressed its expression in lung cancer. By using MTT, flow cytometry and Transwell assays, overexpression of miR-29a restricted both YY1 and N-cadherin expression, and inhibited IL-13-induced invasion of lung cancer A549 cells. Taken together, these findings demonstrate that PI3K/AKT/YY1 is involved in the regulation of lung cancer cell behavior induced by IL-13, and miR-29a represents a promising therapeutic target.

Epithelial–mesenchymal transition (EMT) is a biological process of phenotypic transition of epithelial cells that can promote physiological development as well as tissue healing and repair. In recent years, cancer researchers have noted that EMT is closely related to the occurrence and development of tumors. When tumor cells undergo EMT, they can develop enhanced migration and local tissue invasion abilities, which can lead to metastatic growth. Nevertheless, two researches in NATURE deny its necessity in specific tumors and that is discussed in this review. The degree of EMT and the detection of EMT-associated marker molecules can also be used to judge the risk of metastasis and to evaluate patients’ prognosis. MicroRNAs (miRNAs) are noncoding small RNAs, which can inhibit gene expression and protein translation through specific binding with the 3′ untranslated region of mRNA. In this review, we summarize the miRNAs that are reported to influence EMT through transcription factors such as ZEB, SNAIL, and TWIST, as well as some natural products that regulate EMT in tumors. Moreover, mutual inhibition occurs between some transcription factors and miRNAs, and these effects appear to occur in a complex regulatory network. Thus, understanding the role of miRNAs in EMT and tumor growth may lead to new treatments for malignancies. Natural products can also be combined with conventional chemotherapy to enhance curative effects.