The invention relates to Optineurin-derived polypeptide(s) consisting of a polypeptidic sequence disclosed in SEQ ID N°2, which represents the portion of the wild-type human Optineurin protein sequence from its amino-acid residue 131 to its amino-acid residue 297, or having a polypeptidic sequence encompassing the polypeptidic sequence disclosed in SEQ ID N°2, or having a polypeptidic sequence derived from the polypeptidic sequence disclosed in SEQ ID N°2 to the exclusion of the wild-type Optineurin protein. The polypeptide(s) of the invention retain one, any combination of two, or three of the following functional properties: the capacity to bind Rab8 protein, when the latter are associated with the Golgi apparatus of a cell, the capacity to bind MYPT1 protein, when said protein is engaged in a Myosin-Phosphatase (MP) complex, the capacity to be phosphorylated by Plk1. The invention also relates to nucleic acid molecule(s) encoding such polypeptide(s), vector(s) and method(s) of production thereof, as well as uses thereof, in particular uses in treating cancer(s) or in treating a disease involving mitosis deregulation(s) or alteration(s).
