PSA-alpha-2-macroglobulin complex is enzymatically active in the serum of patients with advanced prostate cancer and can degrade circulating peptide hormones.
Binding of α(2)M* to prostate cancer cell surface GRP78 upregulates mTORC1 and mTORC2 activation and promotes protein synthesis in the prostate cancer cells.
We previously reported that advanced prostate cancer (PCa) patients with multiple distant bone metastases had markedly decreased serum α2M levels (<20 mg/dl) and no detection of α2M by immunoelectrophoresis (defined as α2M deficiency).