The present invention relates to particles comprising RNA, in which the RNA is associated with a cationic polymer or lipid or with both a cationic polymer and lipid, wherein the RNA comprises a cytotoxic nucleotide or cytotoxic nucleotide analog and/or the RNA is covalently attached to a cytotoxin, pharmaceutical compositions containing said particles and pharmaceutical uses of the particles and pharmaceutical compositions. The particles of the present invention are particularly useful as an immunostimulating medicament capable to block proliferation or induce death in dividing cells such as tumor cells.
