Abstract 2964: Saffron has enhanced anti-proliferative effect against colorectal cancer cells with deficient DNA mismatch repair

Background: Colorectal cancer (CRC) is one of the most common cancers worldwide. A subtype of CRC is associated with defective mismatch repair (dMMR) genes. Saffron has many potentially protective roles against colon malignancy, however, these roles in the context of of dMMR have not been explored. In this study, we aimed to study the effects of saffron in CRC cell lines with dMMR. Methods: Saffron crude extracts and specific compounds (crocin, crocetin and safranal) were used in colorectal cancer cell lines HCT116, HCT116+3 (inserted MLH1), HCT116+5 (inserted MH3) and HCT116+3+5 (Inserted MLH1 and MSH3). CDC25b, p-H.H2AX, TPDP1, and GAPDH were analyzed by Western blot. Cell cycle was analyzed by FACS. Proliferation and cytotoxicity were analyzed by MTT. Wound and migration assays were also performed. Results: Saffron crudes restricted the proliferation in colon cells with deficient MMR (HCT116) compared to proficient MMR. Wound healing assay indicates that deficient MMR cells are doing better than proficient MMR cells. The expression of CDC25b and TDP1 were upregulated in proficient MMR cell compared to deficient MMR cell, while H2AX was significantly upregulated in both cells type particularly at >10 mg/ml saffron in a concentration-dependent manner (after normalization with GADPH as control).The reduction in cellular proliferation and motility might be due to cell cycle arrest at G2-phase rather than to apoptosis. The major active saffron compounds, safranal and crocin reproduced total saffron crudes effects but with lesser outcome. Conclusion: Saffron9s anti-proliferative and healing effects is significant in cells with deficient MMR MLH1 and MSH3 genes. This effect may have a therapeutic implications and benefits for the CRC MSI tumors that are generally not recommended for 5FU-based treatment. Citation Format: Amr Amin, Akbar Soleimani, Chandraprabha Murali, Lucie Beresova, Hamid Shoraka, Hassan Brim, Hassan Ashktorab. Saffron has enhanced anti-proliferative effect against colorectal cancer cells with deficient DNA mismatch repair [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2964.