Pharmaceutical compounds, pharmaceutical compositions and methods of treatment are disclosed, wherein a compound comprises a targeting moiety which, in free form, binds a cell receptor with a dissociation constant Kof less than about 10M, and a pharmaceutically active moiety, wherein the targeting moiety is other than an oligopeptide, a polypeptide, a peptidomimetic, a protein or a protein domain, and wherein the targeting moiety and the pharmaceutically active moiety are covalently attached. In some aspects, the targeting moiety binds a sigma-2 receptor with high affinity and high specificity, and the pharmaceutically active moiety is a pro-apoptotic peptide moiety. Methods of cancer treatment are disclosed comprising administering a disclosed pharmaceutical compound to a subject in need of thereof. The treatments selectively induce apoptosis in cancer cells. These methods can further comprise co-administration of radiation therapy and/or an additional chemotherapeutic agent.