Co-localisation of intra-nuclear membrane type-1 matrix metalloproteinase and hypoxia inducible factor-2α in osteosarcoma and prostate carcinoma cells

Increased membrane type-1 matrix metalloproteinase (MT1-MMP) expression in osteosarcoma is predictive of poor prognosis and directs bone metastasis in prostate carcinoma. MT1-MMP subcellular localisation varies with oxygen tension, and, therefore, the aim of the present study was to assess protein interactions between MT1-MMP and the hypoxia inducible factors (HIF-1 alpha and HIF-2 alpha). MT1-MMP protein expression was investigated across a panel of cancer cell lines, including a positive and negative control. The hypoxia-induced alteration in subcellular location of MT1-MMP, HIF-1 alpha and HIF-2 alpha in the U2OS osteosarcoma cell line was assessed using subcellular fractionation. A proximity ligation assay was utilised to assess protein to protein interactions in the osteosarcoma U2OS and prostate carcinoma PC3 cell lines. U2OS and PC3 cells exhibited a significantly increased intra-nuclear interaction between MT1-MMP and HIF-2 alpha in response to hypoxia. The role of this warrants further investigation as it may unveil novel opportunities to target MT1-MMP, which is of particular significance for osteosarcoma since current treatment options are limited.

Automated summary

Increased MT1-MMP expression in osteosarcoma is associated with poor prognosis and bone metastasis in prostate carcinoma. Protein interactions between MT1-MMP and HIF-1α/2α were observed, with a significant intra-nuclear interaction between MT1-MMP and HIF-2α in U2OS and PC3 cells under hypoxia, providing potential novel therapeutic targets for osteosarcoma.