It has been well documented that many cancer cells over express Intreleukin-13 receptors—in particular 4T1 breast carcinoma cell lines and MCA304 sarcoma cell lines (Joshi, 2000). Interleukin-13 (IL-13) is a small, cell-signaling protein that is derived from a Th2 immune response that binds to Interleukin-13 receptors (IL-13R). IL-13Ralpha2 is one of two receptor subunits of the IL-13R complex. This subunit binds IL-13 with high affinity to mediate a signal transduction, ultimately resulting in the production of TGF-beta (Fichtner-Feigl et al., 2006).
Recent studies have focused on targeting IL-13R of tumor cells in order to control the progression of cancer. For this reason, an immunotoxin, IL13-PE, was formulated by recombining IL-13 and Pseudomonas exotoxin in order to target IL-13R expressing tumor cells (Kawakami et al., 2001). IL13-PE is able to specifically recognize IL-13Rs, limiting toxicity to cancerous tissues (Puri et al., 1996). IL13-PE acts to inhibit protein synthesis and cause cell death of IL-13 expressing cells by irreversibly ADP-ribosylating the diphthamide residue of elongation factor 2 (Fichtner-Feigl et al., 2006).
Vaccines have also been utilized as an alternative method to induce a strong immune response against tumor cells. T cells and B cells are leukocytes that are responsible for regulating the immune response by recognizing harmful entities in the body and carrying out their destruction. Antitumor vaccines are intended to incur an antigen-specific immune response against a tumor peptide by priming the immune system to activate T cells and B cells (Nakashima et al., 2010). By stimulating the production of T cells and B cells to recognize tumor cells, the proliferation of tumors can be controlled. One particular vaccine, IL-13Ralpha2 DNA vaccine, has shown to be effective in limiting tumor growth in both 4T1 breast carcinoma cell lines and MCA304 sarcoma cell lines (Nakashima et al., 2010).
