A composition for expressing a polypeptide within a target organ, the composition comprising a delivery particle, and at least a first mRNA sequence complexed with, encapsulated by, or otherwise associated with the delivery particle. The mRNA sequence comprises a coding sequence which codes for the polypeptide, at least a first untranslated region (UTR) sequence, and at least one micro-RNA (miRNA)binding site sequence, wherein the miRNA binding site sequence is located within, immediately 5' to, or immediately 3' to, the first UTR sequence. The miRNA binding site sequence is selected so as toprovide for differential expression of the coding sequence between first and second cell types comprised within the target organ. The composition may be used in combination with or to supplement other therapeutic approaches, including chemotherapy, oncolytic viral therapy, and cellular therapies. Methods for making and using the composition are provided, particularly in treatment of disease, suchas cancer of the liver, brain, lung, breast and pancreas.