DUSP6 promotes motility, invasion, and tumorigenicity of thyroid cancer cells via IL8-induced neutrophil extracellular traps.

This study aims to investigate the role of DUSP6 in thyroid cancer metastasis and elucidate its underlying molecular mechanisms. Immunohistochemistry were performed to explore the expression of DUSP6, IL-8 and PAD4 in papillary thyroid carcinoma (PTC) tissues and adjacent non-cancerous thyroid tissues. Effects of DUSP6 on the proliferation, apoptosis, migration, and invasion of thyroid cancer cell lines TPC-1 and IHH4 were performed through in vitro experiments. A rescue experiment was performed to verified DUSP6 regulated the migration and invasion of thyroid cancer cells TPC-1 and IHH4 through IL-8 and neutrophil extracellular traps (NETs) formation. In addition, in vitro cell experiments were conducted to analyze the regulation of NETs formation by DUSP6 through IL-8. Finally, the effect of sh-DUSP6 on the growth of thyroid cancer tumors in mice were conducted through in vivo experiments. DUSP6 expression was significantly upregulated in PTC tissues. Moreover, the expression of DUSP6 in tumor tissues of TPC patients is positively correlated with the expression of IL-8 and PAD4. Overexpression of DUSP6 promotes the proliferation, migration, and invasion of thyroid cancer cells (TPC-1 and IHH4) while inhibiting apoptosis. Conversely, silencing DUSP6 exerts opposing effects. Knockdown of IL-8 reverses the enhanced migratory and invasive capabilities induced by DUSP6 overexpression in these cell lines. NETs treatment enhances the migration and invasion of TPC-1 and IHH4 cells, whereas the application of sh-DUSP6 or sh-IL-8 counteracts this NETs-mediated promotion. Furthermore, DUSP6 overexpression facilitates NETs formation by upregulating IL-8 expression. In vivo experiments demonstrate that sh-DUSP6 suppresses thyroid cancer tumor growth in mouse models. Conclusion: DUSP6 promotes the metastasis of thyroid cancer by facilitating the formation of neutrophil extracellular traps via IL-8.