FIG 2.

Pharmacological and genetic inhibition of SUV39H1 activity restores IFN production upon poly(dA·dT) transfection in HPV-transformed cells. (A) ELISA quantitation of IFN-β and IFN-λ₁ protein in supernatants from cells treated with chaetocin (150 nM) or vehicle (DMSO) for 6 h and mock transfected or transfected with poly(dA·dT) for 24 h. Data are presented as mean values from biological triplicates. Error bars indicate SD. *, P < 0.05; **, P < 0.01 (unpaired t test). (B) Acid extracts from SUV39H1-deficient (KO) HeLa and CaSki or wild-type (WT) cells were subjected to immunoblot analysis with anti-SUV39H1, anti-H3K9me3, anti-H3K27me3, or anti-PAN-H3 antibodies. The densitometry values of protein bands were normalized to those of PAN-H3. Values are representative of three independent experiments. Error bars indicate SD. *, P < 0.05; **, P < 0.01 (unpaired t test). (C) Transcript levels of the indicated genes were assessed by qPCR in cells described in panel B, and values were normalized to those of GAPDH, with the WT mock-transfected cell value set to 1. Data are presented as mean values from biological triplicates. Error bars indicate SD. *, P < 0.05 (unpaired t test). (D) HeLa and CaSki SUV39H1 KO or control cells were subjected to immunoblot analysis with anti-RIG-I, anti-cGAS, anti-STING, or anti-tubulin antibodies. The densitometry values of protein bands were normalized to those of tubulin. Values are representative of three independent experiments. Error bars indicate SD. *, P < 0.05 (unpaired t test). (E) ELISA quantitation of IFN-β and IFN-λ₁ protein in supernatants from HeLa and CaSki SUV39H1 KO or control cells mock transfected or transfected with poly(dA·dT) for 24 h. Data are presented as mean values from biological triplicates. Error bars indicate SD. *, P < 0.05 (unpaired t test).