Innate immune response to G-quadruplex binders in cancer cells

G-quadruplex (G4) is non-canonical nucleic acid structure involved in a plethora of fundamental biological processes. In past decades, it has been studied as a promising pharmaceutical target for anticancer therapy. However, no G4-targeting agent has shown significant clinical effects up to date. Pyridostatin (PDS), a well-known G4 binder, can induce double-stranded DNA breaks and genome instability. We have recently shown that Pyridostatin (Pyridostatin) and other G4 binders can trigger micronuclei formation in cancer cells at non-cytotoxic concentrations. As micronuclei can play a crucial role in linking genome instability to innate immunity, we have here wondered whether G4 binders can induce immune gene activation in human MCF-7 breast cancer cells. Overall design: By using RNA seq technology, we show that non-cytotoxic doses of Pyridostatin (PDS) can activate Interferon beta- and IRF3-dependent genes leading to an innate immune gene response in human cancer cells. In addition, immune gene activation follows the induction of micronuclei formation supporting cytoplasmic DNA as a trigger of immune gene activation.