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Breast cancer is the most common type of invasive cancer in females and metastasis is one of the major causes of breast cancer-associated mortality. Following detachment from the primary site, disseminated tumor cells (DTCs) enter the bloodstream and establish secondary colonies during the metastatic process. An increasing amount of studies have elucidated the importance of Notch signaling in breast cancer metastasis; therefore, the present review focuses on the mechanisms by which Notch contributes to the occurrence of breast cancer DTCs, increases their motility, establishes interactions with the tumor microenvironment, protects DTCs from host surveillance and finally facilitates secondary colonization. Identification of the underlying mechanisms of Notch-associated breast cancer metastasis will provide additional insights that may contribute towards the development of novel Notch-targeted therapeutic strategies, which may aid in reducing metastasis, culminating in an improved patient prognosis.

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.

Interleukin-13 (IL-13), a Th2 cytokine, plays an important role in fibrosis, inflammation, tissue hyperresponsiveness and tumor development. Although studies have demonstrated that IL-13 exerts its roles through signal transducer and activator of transcription 6 (STAT6) signaling pathway, recent studies have revealed that I kappa B kinase (IKK)/nuclear factor kappa B (NFκB) pathway may also be involved in. The aim of this study was to investigate whether IL-13 delivers signals to IKKβ/NFκBp65 and whether autophagy genes are IL-13-induced the activation of NFκBp65 transcriptional targets in fibroblasts of breast tumor stroma. We examined the phosphorylation of IKKβ, the activation of NFκBp65 and NFκBp65-targeted autophagy genes in fibroblasts co-cultured with breast cancer cells under the condition of IL-13 stimulation. Results of this study showed that IL-13 induced IKKβ phosphorylation in the fibroblast line ESF co-cultured with breast cancer cell line BT474, and subsequently NFκBp65 was activated and aimed at beclin 1 and microtubule-associated protein 1 light chain 3 B (MAP1LC3B or LC3B) in these ESF cells. BMS345541, an inhibitor of IKK/NFκB pathway, significantly inhibited the IL-13-induced the activation of NFκB and also inhibited NFκB-targeted beclin 1 and LC3B expression. Our results suggest that IL-13 regulates beclin 1 and LC3B expression through IKKβ/NFκBp65 in fibroblasts co-cultured with breast cancer cells, and IL-13 plays role in activating IKKβ/NFκBp65.