| Mechanism of Action | Interferon gamma signals as an antiparallel homodimeric glycoprotein, acting at the complex of interferon gamma receptor 1 (IFNGR1) and IFNGR2 after direct binding to IFNGR1. It activates the JAK/STAT, MAPK, and PI3-Kinase pathways. In addition, Interferon gamma activates macrophages, mediates antiviral and antibacterial immunity, regulates Th1/Th2 balance, and controls cellular proliferation and apoptosis. It is currently being investigated as an antitumor drug, and a therapy for juvenile rheumatoid arthritis, chemoresistant pulmonary tuberculosis, idiopathic pulmonary fibrosis, and atypical pulmonary mycobacteriosis. This cytokine has been found to have effects such as promotion of host response in antitumor immunity, playing roles in all three phases (elimination, equilibrium, and escape) of cancer immunoediting, directly influencing antiproliferation, apoptosis, and antiangiogenesis on tumor cells, and indirectly influencing antitumor immunity. However, currently there is no approved indication report of using interferon gamma in cancer treatment, indicating that interferon has not yet reached a stage of being a clinically-useful antitumor drug. Interferon gamma, when administered in combination with interferon alpha-2-beta as part of the HerberFERON therapy, is found to have synergistic effects, with the potential for more favorable pharmacodynamics than either alone. This synergy between interferon alpha and gamma include antiproliferative effects on several cancers. |