Scutellarin resensitizes oxaliplatin-resistant colorectal cancer cells to oxaliplatin treatment through inhibition of PKM2

Although oxaliplatin is an effective chemotherapeutic drug commonly used for colorectal cancer (CRC) treatment, drug resistance usually occurs during the long-term use of it. It is urgent to create strategies to reduce the resistance of CRC cells to oxaliplatin. Oxaliplatin-resistant CRC cells (OR-SW480 and OR-HT29) were acquired through long-term exposure of CRC cells to oxaliplatin. It was found that OR-SW480 and OR-HT29 cells exhibited obvious lower sensitivity and a higher metabolism rate of glucose compared to their parental SW480 and HT29 cells, respectively. However, combination with scutellarin significantly resensitized the OR-SW480 and OR-HT29 cells to oxaliplatin-induced cytotoxicity. Mechanically, overexpression of pyruvate kinase isoenzyme M2 (PKM2) was responsible for the resistance to oxaliplatin in OR-SW480 and OR-HT29. Combination with scutellarin was able to inhibit the PKM2 activity and thus reduced the production of adenosine triphosphate (ATP) to sensitize the oxaliplatin-induced mitochondrial apoptosis pathway in both OR-SW480 and OR-HT29 cells. It was indicated that scutellarin resensitizes oxaliplatin-resistant CRC cells to oxaliplatin treatment through inhibition of PKM2.