Quarfloxin (CX-3543), a fluoroquinolone derivative with antineoplastic activity, targets and inhibits RNA pol I activity, with IC50 values in the nanomolar range in neuroblastoma cells. Quarfloxin disrupts the interaction between the nucleolin protein and a G-quadruplex DNA structure in the ribosomal DNA (rDNA) template[1]. RNA pol I[1].
Quarfloxin (CX-3543) effectively inhibits the growth of neuroblastoma cells in vitro. MNA (or high c-Myc) and wt-TP53 cell lines are found to be more sensitive to Quarfloxin. Quarfloxin and induces DNA damage, p53 signaling, cell death, and cell cycle arrest in neuroblastoma cell lines[1].
[1]. Hald ØH, et al. Inhibitors of ribosome biogenesis repress the growth of MYCN-amplified neuroblastoma. Oncogene. 2018 Dec 12.