Curcumin Synergizes with Cisplatin to Inhibit Colon Cancer through Targeting the MicroRNA-137-Glutaminase Axis

Objective Colorectal cancer (CRC) is one of the most lethal and prevalent malignancies world-wide. Currently, surgery, radiotherapy and chemotherapy are clinically applied as common approaches for CRC patients. Cisplatin is one of the most frequently used chemotherapy drugs for diverse cancers. Although chemotherapeutic strategies have improved the prognosis and survival of cancer patients, development of cisplatin resistance has led to cancer recurrence. Curcumin, isolated from turmeric, has been used as an effective anti-cancer agent. However, the molecular mechanisms for curcumin-mediated cisplatin sensitivity of CRC have not been elucidated. This study aimed to investigate the effects of curcumin treatment on cisplatin-resistant CRC cells. Methods Expression levels of miRNAs and mRNAs were determined by qRT-PCR. Protein expression levels were detected by Western blotting. Cell responses to curcumin treatments were evaluated by MTT assay, Clonogenic assay and Annexin V apoptosis assay. The glutamine metabolism of colon cancer cells was assessed by glutamine uptake and glutaminase (GLS) activity. The binding of miR-137 on 3′ UTR of GLS was validated by Western blotting and luciferase assay. Results Results demonstrated that curcumin significantly synergized with cisplatin (combination index