Chloroquine as a promising adjuvant chemotherapy together with sunitinib

Abstract

Chloroquine -a clinically available and cheap antimalarial drug -might have potential usefulness as adjuvant chemotherapy when combined with sunitinib, reports a preclinical study recently published online in Chemico-biological Interactions. Just few years after its FDA approval to be used in imatinib resistant gastrointestinal tumor, renal carcinoma and pancreatic neuroendocrine tumor, light has been shed on the limited clinical efficacy of sunitinib as well as rapid development of resistant cells when used as monotherapy. Abdel-Aziz and her colleagues now showed that chloroquine augments sunitinib anticancer activity in vitro human cancer cell lines of breast, colorectal, cervical, laryngeal, liver and prostate origin and in vivo in murine Ehrlich ascites carcinoma tumor model. Furthermore, chloroquine interrupted autophagic flux which was induced by sunitinib. They noted that chloroquine when combined with sunitinib showed further activation of apoptosis in cancer cells. The observed synergy was associated with increased nitric oxide and reduced reactive oxygen species levels. The present findings warrant further studies to explore the safety profile of the combination regimen and its clinical usefulness in vivo and then in controlled clinical trials.