DNMT1 and osteosarcoma: Prompted by the evidence that 1 decreased DNMT expression in primary osteosarcoma cells [28], and 4 phenocopied similar effects in HCT116 and PC-3 cells [29], we tested selected compounds 2b and 4c as representative samples of the 2 and 4 series to study their effects on DNMT1 and DNMT3A protein expression.