Integrins: Molecular targets in cancer therapy

Integrins are cell surface adhesion molecules coupling the extracellular environment to the cytoskeleton as well as receptors for transmitting signals important for cell migration, invasion, proliferation, and survival. At least six integrin inhibitors are being evaluated in clinical trials for cancer. Currently, patients with melanoma and glioblastoma multiforme benefit from Vitaxin (MedImmune, Gaithersburg, MD) or cilengitide treatment, respectively. Many phase II trials are being or have been conducted with these two compounds (the most advanced). Surprisingly, despite the broad theoretical impact of such molecules on integrin function, and thus on pathology, the clear identification of discrete clinical niches for their use remains to be defined. Possible reasons for this are discussed in this review. The parallel development of integrin antagonists as imaging tools for patient selection may accelerate the discovery of new avenues for their use.

Molecularly targeted therapy for melanoma

Effective therapy for melanoma remains an unmet goal, with most traditional therapies representing inadequate trade-offs among the several goals of specificity, efficacy, and toxicity. Targeted molecular therapeutics are tailored to genetic abnormalities that are associated with tumor progression. Modulation of aberrant signaling pathways in cancer cells has the potential to provide more effective and potentially nontoxic therapy for a broad range of cancers, including melanoma. Among the possible targets in melanoma are the Ras-MAPK and PI3K/AKT signal transduction pathways, the proteasome, histone deacetylases, methyltransferases, and melanoma-induced angiogenesis.