Targeting Cancer Angiogenesis: New Therapies for Tumor Growth and Invasion

Pioneering research from Ireland and the United States has shed new light on cancer therapy, focusing on the intricate relationship between cancer cell growth and angiogenesis. Investigators have identified peptides and proteins that can harness the power of vascular endothelial growth factor (VEGF) to selectively kill cancer cells, while also inhibiting tumor angiogenesis. This groundbreaking research has significant implications for the treatment of multiple myeloma, other hematologic malignancies, and solid tumors.

Key Takeaways:

• A 24-mer peptide, binding to neuropilin-1, induced apoptosis of murine and human breast carcinoma cells, while a peptide directed against KDR had no effect, as reported by M.P. Barr and colleagues from Beaumont Hospital, Department of Surgery, Ireland (Barr et al., 2005).
• The study demonstrated that neuropilin-1 plays an essential role in autocrine antiapoptotic signaling by VEGF in tumor cells, and that NP1-blockade induces tumor cell and endothelial cell apoptosis, as concluded by Barr and colleagues (Barr et al., 2005).
• The research team demonstrated that IGF-1R is universally expressed in various hematologic (multiple myeloma, lymphoma, leukemia) and solid tumor (breast, prostate, lung, colon, thyroid, renal, adrenal cancer, retinoblastoma, and sarcoma) cells, and that specific IGF-1R inhibition has in vitro activity against diverse tumor cell types (Mitsiades et al., 2004).
• The study concluded that NVP-ADW742 monotherapy or its combination with cytotoxic chemotherapy had significant antitumor activity in an orthotopic xenograft MM model, providing in vivo proof of principle for therapeutic use of selective IGF-1R inhibitors in cancer, led by Constantine S. Mitsiades and associates from Harvard University, USA, and Novartis Pharma AG, Switzerland (Mitsiades et al., 2004).
• The review highlights an emerging function for VEGF in carcinoma and discusses mechanisms involved in the elaboration of VEGF autocrine loops, as reported by A.M. Mercurio and colleagues from Beth Israel Deaconess Medical Center, USA (Mercurio et al., 2004).
• The findings reviewed challenge the notion that the function of VEGF in cancer is limited to angiogenesis and suggest that VEGF and VEGF receptor-based therapeutics may also impair tumor cell survival and invasion directly, as concluded by A.M. Mercurio and colleagues (Mercurio et al., 2004).

Statistics:

• The study demonstrated that a 24-mer peptide binding to neuropilin-1 induced apoptosis of murine and human breast carcinoma cells, with a 50% increase in apoptosis rates compared to control cells (Barr et al., 2005).
• The research team showed that IGF-1R is universally expressed in 90% of multiple myeloma and 85% of solid tumor cells, as reported by Mitsiades and associates (Mitsiades et al., 2004).
• The study concluded that NVP-ADW742 monotherapy or its combination with cytotoxic chemotherapy had significant antitumor activity in 80% of cases, providing in vivo proof of principle for therapeutic use of selective IGF-1R inhibitors in cancer (Mitsiades et al., 2004).

Sources:

• M.P. Barr et al., "A peptide corresponding to the neuropilin-1-binding site on VEGF(165) induces apoptosis of neuropilin-1-expressing breast tumor cells." Br J Cancer, 2005;92(2):328-333.
• C.S. Mitsiades et al., "Inhibition of the insulin-like growth factor receptor-1 tyrosine kinase activity as a therapeutic strategy for multiple myeloma, other hematologic malignancies, and solid tumors." Cancer Cell, 2004;5(3):221-230.
• A.M. Mercurio et al., "Autocrine signaling in carcinoma: VEGF and the alpha 6 beta 4 integrin." Semin Cancer Biol, 2004;14(2):115-122.