As disclosed herein, stapled peptides targeting the interaction interface between proteins that maintain the integrity of Wiskott-Aldrich syndrome protein family member 3 (WASF3) leads to destabilization of WASF3 and suppression of invasion. Disclosed are stapled peptides that inhibit the binding of Cytoplasmic FMR1-interacting protein 1 (CYFIP1) to either WASF3 or NCK-associated protein (NCKAP1). Also disclosed are methods for treating or suppressing invasion and metastasis of a cancer in a subject that involve administering to the subject a therapeutically effective amount of a stapled peptide disclosed herein.