The CtIP-CtBP1/2-HDAC1-AP1 transcriptional complex is required for the transrepression of DNA damage modulators in the pathogenesis of osteosarcoma

•CtIP couples with CtBP1/2 heterodimer, HDAC1, and two subunits of AP1 transcription factor to assemble a complex.•The CtIP-CtBP1/2-HDAC1-AP1 complex is required for the inhibition of MLH1, MSH3, BRCA1, and CDKN1A in osteosarcoma cells.•Overexpression of MLH1, MSH3, BRCA1, and CDKN1A in osteosarcoma cells inhibits tumor cell growth in vitro and in vivo.