Polyinosinic-polycytidylic acid sodium (Poly(I:C) sodium) is a synthetic analog of double-stranded RNA and an agonist of toll-like receptor 3 (TLR3) and retinoic acid inducible gene I (RIG-I)-like receptors (RIG-I and MDA5). Polyinosinic-polycytidylic acid sodium can be used as a vaccine adjuvant to enhance innate and adaptive immune responses, and to alter the tumor microenvironment. Polyinosinic-polycytidylic acid sodium can directly trigger cancer cells to undergo apoptosis[1][2].

Polyinosinic-polycytidylic acid (20 ng/mL; 24 hours; WM793, WM278, WM239A, WM9 and 1205Lu cells) treatment strongly reduces viability from 100% in controls to 20%-50% within 24 hours[1].Polyinosinic-polycytidylic acid (200 ng/mL; 24 hours; 1205Lu cells) treatment induces apoptosis in 1205Lu cells[1].Polyinosinic-polycytidylic acid (3 ng/mL; 24 hours; 1205Lu cells) treatment induces IFN-β expression in melanoma cells. Silencing of RIG-I and MDA-5 confirmed that induction of IFN-β by Polyinosinic-polycytidylic acid required RIG-I and MDA-5, respectively, and that required IPS-1[1].Polyinosinic-polycytidylic acid (5 ng/mL; 24 hours; 1205Lu cells) treatment reveals active subunits of caspase-9 and caspase-8 in melanoma cells[1]. Cell Viability Assay[1] Cell Line: WM793, WM278, WM239A, WM9 and 1205Lu cells

Polyinosinic-polycytidylic acid treatment inhibits tumor growth in NOD/SCID immunodeficient mice injected with 1205Lu cells. The level of human DNA is 50% lower in mice treated with Polyinosinic-polycytidylic acid[1].

[1]. Besch R, et al. Proapoptotic signaling induced by RIG-I and MDA-5 results in type I interferon-independent apoptosis in human melanoma cells. J Clin Invest. 2009 Aug;119(8):2399-411. [2]. Cheng YS, et al. Anticancer function of polyinosinic-polycytidylic acid. Cancer Biol Ther. 2010 Dec 15;10(12):1219-23.