The present invention relates to a N1-methyl-pyrazoloanthrone, e.g., a N1-methyl 1,9-pyrazoloanthrone or functional derivatives or analogues thereof to inhibit at least one kinase of the CK1 family (e.g., CSNK1A1, CSNK1B, CSNK1G1, CSNK1G2, CSNK1G3, CSNK1D, CSNK1E) and/or ARK5/NUAK1 in a cell. Another aspect relates to administration of N1-methyl-pyrazoloanthrone, e.g., a N1-methyl 1,9-pyrazoloanthrone or a functional derivative thereof in a method to treat cancer, e.g., a cancer with increased expression and/or a genetic alteration in at least one member of the CK1 family and/or ARK5/NUAK. Another aspect of the present invention relates to methods to decrease the dose of a chemotherapeutic agent by administering the chemotherapeutic agent in combination with a N1-methyl-pyrazoloanthrone, e.g., a N1-methyl 1,9-pyrazoloanthrone or a functional derivative or analogue thereof.
