Methods and compositions inhibiting tumor cell proliferation
The invention provides agents, compositions, pharmaceutical compositions and method for inhibiting tumor cell proliferation by inhibiting FoxM1B activity, expression, or nuclear localization in a tumor cell.
1. A method of eliminating a liver cancer stem cell comprising the step of contacting the liver cancer stem cell with a polypeptide comprising (1) a p19Arf peptide fragment comprising amino acid residues KFVRSRRRPTASCALAFVN (SEQ ID NO: 16), and (2) an HIV Tat peptide of SEQ ID NO:17 or a nine-D-Arg peptide of SEQ ID NO:18 that is covalently linked to the N-terminus of the p19Arf peptide fragment, wherein the polypeptide is modified at both the N terminus and the C terminus, wherein the N terminus is modified by acetylation and wherein the C terminus is modified by amidation.
2. The method of claim 1 , wherein the modified polypeptide has the amino acid sequence of SEQ ID NO:19.