ADAMTS4 exacerbates lung cancer progression via regulating c-Myc protein stability and activating MAPK signaling pathway.

BACKGROUND: Lung cancer is one of the most frequent cancers and the leading cause of cancer-related deaths worldwide with poor prognosis. A disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS4) is crucial in the regulation of the extracellular matrix (ECM), impacting its formation, homeostasis and remodeling, and has been linked to cancer progression. However, the specific involvement of ADAMTS4 in the development of lung cancer remains unclear. METHODS: ADAMTS4 expression was identified in human lung cancer samples by immunohistochemical (IHC) staining and the correlation of ADAMTS4 with clinical outcome was determined. The functional impact of ADAMTS4 on malignant phenotypes of lung cancer cells was explored both in vitro and in vivo. The mechanisms underlying ADAMTS4-mediated lung cancer progression were explored by ubiquitination-related assays. RESULTS: Our study revealed a significant upregulation of ADAMTS4 at the protein level in lung cancer tissues compared to para-carcinoma normal tissues. High ADAMTS4 expression inversely correlated with the prognosis of lung cancer patients. Knockdown of ADAMTS4 inhibited the proliferation and migration of lung cancer cells, as well as the tubule formation of HUVECs, while ADAMTS4 overexpression exerted opposite effects. Mechanistically, we found that ADAMTS4 stabilized c-Myc by inhibiting its ubiquitination, thereby promoting the in vitro and in vivo growth of lung cancer cells and inducing HUVECs tubule formation in lung cancer. In addition, our results suggested that ADAMTS4 overexpression activated MAPK signaling pathway. CONCLUSIONS: We highlighted the promoting role of ADAMTS4 in lung cancer progression and proposed ADAMTS4 as a promising therapeutic target for lung cancer patients.