The present Invention relates to a method of inhibiting or reducing the proliferation of prostate cancer cells, such as androgen independent prostate cancer (AIPC) cells, the method comprising administering to the cells a PLA 2 inhibitor. In one embodiment the PLA 2 inhibitor is a conformationally constrained molecule derived from a peptide consisting essentially of amino acid residues 70-74 of a human sPLA 2 -IIA protein, or the equivalent residues in other sPLA 2 proteins.