In the current study, utilizing a genetic mouse model of advanced prostate cancer with hyperactivated metastasis-associated protein 1/mammalian target of rapamycin (MTA1/mTOR) tumor-promoting pathway, we show for the first time that gnetin C, a natural compound from the melinjo plant, blocks the progression of prostate cancer by reducing cell proliferation and angiogenesis and promoting cell death through the efficient targeting of the MTA1/mTOR pathway. Here, MTA1 is linked to Familial prostate cancer.