Terpenoids from quinoa reverse drug resistance of colon cancer by upregulating miR-495-3p.

BACKGROUND: Quinoa contains far more nutrients than any traditional grain crop. It is known that terpenoids in quinoa have anti-inflammatory and antitumor effects, but their role in reversing drug resistance remains unclear. RESULTS: Our previous studies showed that quinoa-derived terpenoid compounds (QBT) can inhibit the occurrence and development of colon cancer. This study further indicates that QBT markedly reverse drug resistance of colon cancer. The results showed that QBT combined with 5-fluorouracil (5-Fu) treatment significantly enhanced the chemotherapy sensitivity of HCT-8/Fu, compared with 5-Fu treatment alone. Moreover, we found that QBT significantly reduced the expression of drug-resistant proteins (P-gp, MRP1, BCRP), and increased the accumulation of chemotherapy drugs. Taking P-gp as the target for biogenesis prediction analysis, results showed that upregulation of miR-495-3p enhanced the chemosensitivity of drug-resistant HCT-8/Fu cells. Besides, the results showed that miR-495-3p was abnormally methylated in HCT-8/Fu compared with HCT-8 colon cancer cells. The expression of methyltransferases DNMT1, DNMT3a and DNMT3b was abnormal. After QBT treatment, the expression level of methyltransferases returned to normal. In addition, the QBT + 5Fu group showed inhibition of tumors in nude mice. CONCLUSION: QBT treatment downregulated the expression of drug-resistant protein P-gp by inhibiting the methylation of miR-495-3p, and enhanced the accumulation of 5-Fu in vivo, which in turn reversed its chemoresistance. This suggests that QBT has potential ability as a new drug-resistance reversal agent in colorectal cancer. © 2024 Society of Chemical Industry.

Polyunsaturated Fatty Acids in Quinoa Induce Ferroptosis of Colon Cancer by Suppressing Stemness.

Polyunsaturated fatty acids (PUFAs) are essential nutrients for the human body, playing crucial roles in reducing blood lipids, anti-inflammatory responses, and anticancer effect. Quinoa is a nutritionally sound food source, rich in PUFAs. This study investigates the role of quinoa polyunsaturated fatty acids (QPAs) on quelling drug resistance in colorectal cancer. The results reveal that QPA downregulates the expression of drug-resistant proteins P-gp, MRP1, and BCRP, thereby enhancing the sensitivity of colorectal cancer drug-resistant cells to the chemotherapy drug. QPA also inhibits the stemness of drug-resistant colorectal cancer cells by reducing the expression of the stemness marker CD44. Consequently, it suppresses the downstream protein SLC7A11 and leads to ferroptosis. Additionally, QPA makes the expression of ferritin lower and increases the concentration of free iron ions within cells, leading to ferroptosis. Overall, QPA has the dual-function reversing drug resistance in colorectal cancer by simultaneously inhibiting stemness and inducing ferroptosis. This study provides a new option for chemotherapy sensitizers and establishes a theoretical foundation for the development and utilization of quinoa.

QPH-FR: A Novel Quinoa Peptide Enhances Chemosensitivity by Targeting Leucine-Rich Repeat-Containing G Protein-Coupled Receptor 5 in Colorectal Cancer.

Chemoresistance is one of the difficulties in the treatment of colorectal cancer (CRC), and the enhanced stemness of tumor cells is the underlying contributing factor. Leucine-rich repeat-containing G-protein-coupled receptor 5 (LGR5) is a classical marker of CRC stem cells and can be an important potential target for CRC chemotherapy. Quinoa, a protein-rich plant, offers potential as a source of high-quality active peptides. Novelly, the study obtained quinoa protein hydrolysate (QPH) from whole quinoa grains by simulated digestion. In vivo experiments revealed that the tumor volume in the 5-FU+QPH group decreased from 145.90 ± 13.35 to 94.49 ± 13.05 mm3 in the 5-FU group, suggesting that QPH enhances the chemosensitivity of CRC. Further, the most effective peptide QPH-FR from 631 peptides in QPH was screened by activity prediction, molecular docking, and experimental validation. Mechanistically, QPH-FR competitively suppressed the formation of the LGR5/RSPO1 complex by binding to LGR5, causing RNF43/ZNRF3 to ubiquitinate the FZD receptor, thereby suppressing the Wnt/ß-catenin signaling pathway and exerting stemness inhibition. In summary, the study proposes that a novel peptide QPH-FR from quinoa elucidates the mechanism by which QPH-FR targets LGR5 to enhance chemosensitivity, providing theoretical support for the development of chemotherapeutic adjuvant drugs based on plant peptides.