According to the present invention, an apoptosis-inducing agent for prostate cancer comprising REIC/Dkk-3 DNA or an REIC/Dkk-3 protein, and a therapeutic agent for prostate cancer and an agent for inhibiting prostate cancer metastasis that comprise such apoptosis-inducing agent are provided.An apoptosis-inducing agent for prostate cancer, comprising, as an active ingredient, an REIC/Dkk-3 protein (a) or (b) or REIC/Dkk-3 DNA (c) or (d):(a) a protein consisting of the amino acid sequence represented by SEQ ID NO: 2(b) a protein consisting of an amino acid sequence derived from the amino acid sequence represented by SEQ ID NO: 2 by substitution or deletion of 1 or more amino acids(c) DNA consisting of the nucleotide sequence represented by SEQ ID NO: 1 or(d) DNA that hybridizes under stringent conditions to DNA consisting of a nucleotide sequence complementary to the nucleotide sequence represented by SEQ ID NO: 1 and encodes a protein having apoptosis activity anda therapeutic agent for prostate cancer comprising such apoptosis-inducing agent are provided.
