The present invention provides a method of treating a cancer associated with a mutation in a subject in need thereof. The method comprises the steps of (1) identifying a subject with a cancer associated with a K-ras mutation; and (2) adminsiterign to the subject (i) an inhibitor of PI3 kinase and (ii) an HDAC inhibitor, wherein the PI3 kinase inhibitor and the HDAC inhibitor are administered in amounts which together are therapeutically effective.