A method for treating a solid tumor comprising a population of tumor-propagating cells with stem-like characteristics (TPCs) in a subject, comprising administering to the subject a pharmaceutical composition comprising a peptide derivative of Wnt5a, wherein the peptide derivative comprises amino acid sequence LECGDM (SEO ID NO:
- 2), or amino acid sequence LEGDM (SEO ID NO:
- 3), or a combination of peptide derivatives comprising LECGDM (SEO ID NO:
- 2) and LEGDM (SEO ID NO:
- 3), and wherein the peptide derivative is formulated per se or in salt form.