Compositions and methods for the treatment and diagnosis of diseases or disorders amenable to treatment through modulation of Activating Protein 1 (AP-1) expression are provided. In accordance with various embodiments of the present invention, oligonucleotides are provided which are specifically hybridizable with c-fos or c-jun, the genes encoding c-Fos or c-Jun, respectively. In a preferred embodiment, a method of modulating the metastasis of malignant tumors via modulation of one or more of the AP-1 subunits is provided; this method can be effected using the oligonucleotides of the invention or any other agent which modulates AP-1 or AP-1-mediated transcription.