Curcumin functions as a MEK inhibitor to induce a synthetic lethal effect on KRAS mutant colorectal cancer cells receiving targeted drug regorafenib

Chi Shiuan Wu, Shan Ying Wu, Hsin Chih Chen, Chien An Chu, Han Hsuan Tang, Hsiao Sheng Liu, Yi Ren Hong, Chi Ying F. Huang, Guan Cheng Huang, Chun Li Su

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Curcumin, a major yellow pigment and spice in turmeric and curry, has been demonstrated to have an anticancer effect in human clinical trials. Mutation of KRAS has been shown in 35%-45% of colorectal cancer, and regorafenib has been approved by the US FDA to treat patients with colorectal cancer. Synthetic lethality is a type of genetic interaction between two genes such that simultaneous perturbations of the two genes result in cell death or a dramatic decrease of cell viability, while a perturbation of either gene alone is not lethal. Here, we reveal that curcumin significantly enhanced the growth inhibition of regorafenib in human colorectal cancer HCT 116 cells (KRAS mutant) to a greater extent than in human colorectal cancer HT-29 cells (KRAS wild-type), producing an additive or synergistic effect in HCT 116 cells and causing an antagonistic effect in HT-29 cells. Flow cytometric analysis showed that the addition of curcumin elevated apoptosis and greatly increased autophagy in HCT 116 cells but not in HT-29 cells. Mechanistically, curcumin behaved like MEK-specific inhibitor (U0126) to enhance regorafenib-induced growth inhibition, apoptosis and autophagy in HCT 116 cells. Our data suggest that curcumin may target one more gene other than mutant KRAS to enhance regorafenib-induced growth inhibition (synthetic lethality) in colorectal cancer HCT 116 cells, indicating a possible role of curcumin in regorafenib-treated KRAS mutant colorectal cancer.

Original languageEnglish
Article number108227
JournalJournal of Nutritional Biochemistry
Publication statusPublished - Dec 2019



  • Chemosensitivity
  • Curcumin
  • FDA-approved anticancer drugs
  • MEK inhibition
  • Regorafenib
  • Synthetic lethality

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Biochemistry
  • Molecular Biology
  • Nutrition and Dietetics
  • Clinical Biochemistry

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