STAT3 as a Major Contributor to Chemoresistance

Signal transducer and activator of transcription 3 (STAT3) is a well-validated anticancer target that promotes tumorigenesis. Although it has historically been considered "undruggable", multiple classes of direct STAT3 inhibitors have recently been discovered that successfully abrogate STAT3 activation or DNA-binding activity, ultimately generating selective cytotoxicity against cancerous cells. Considering the growing body of evidence implicating STAT3 in the development of treatment resistance, direct STAT3 inhibitors have promising potential to augment the antitumor effects of conventional chemotherapy drugs, radiation, and molecular targeting agents, leading to improved patient outcomes. This chapter focuses on the progress made in developing direct STAT3 inhibitors and their evaluation in preclinical models and clinical trials.