Saudi Pharm J. 2022 Jan;30(1): 72-90
Excessive interleukin (IL)-6 production is a driver for malignancy and drug resistance in colorectal cancer (CRC). Our study investigated a seven-week post-treatment with the anti-inflammatory drug, Diacerein (Diac), alone or in combination with 5-fluorouracil (5-FU), using a 1,2-dimethylhydrazine (DMH) rat model of CRC. Diac alone and 5-FU+Diac reduced serum levels of carcino-embryonic antigen (CEA), while all regimens decreased serum levels of colon cancer-specific antigen (CCSA), a more specific CRC biomarker. Additionally, Diac, 5-FU and their combination suppressed colonic content/gene expression of IL-6, its downstream oncogene, Kirsten rat sarcoma viral oncogene homolog (K-Ras), and consequently Notch intracellular domain and nuclear factor-kappa B (NF-κB) p65. In turn, NF-κB downstream factors, viz., matrix metalloproteinase-9 (MMP-9), vascular endothelial growth factor (VEGF), c-Myc, and B-cell lymphoma-2 (Bcl-2) were also downregulated, while E-cadherin was elevated. Additionally, the drugs reduced the immunoreactivity of CD31 to prove their anti-angiogenic effect, while the TUNEL assay confirmed the apoptotic effect. The apoptotic effect was confirmed by transferase dUTP nick-end labeling assay. Moreover, these drugs inhibited colon content of p-Akt, β-catenin, and cyclin D1 immunoreactivity. The drugs also activated the tumor suppressor glycogen synthase kinase 3- β (GSK3-β) and upregulated the expression of the Nur77 gene, which represents the second arm of IL-6 signaling. However, only 5-FU upregulated miR-200a, another K-Ras downstream factor. The in-vitro cytotoxic and migration/invasion assays verified the molecular trajectories. Accordingly, we evaluated the antineoplastic effect of Diac alone and its possible chemosensitization effect when added to 5-FU. This combination may target critical oncogenic pathways, including the IL-6/K-Ras/Notch/NF-κB p65 axis, p-Akt/GSK3-β/β-catenin/cyclin D-1 hub, and Nur77.
Keywords: 5-FU, 5-flurouracil; 5-fluorouracil; ANOVA, analysis of variance; Akt, protein kinase B; BSA, bovine serum albumin; Bcl-2, B-cell lymphoma-2; CCSA-2, colon cancer specific antigen; CD 31, cluster of differentiation 31; CDK, cyclin dependent kinase; CEA, carcino-embryonic antigen; CRC, colorectal cancer; Colorectal cancer; Ct, cycle threshold; DAB, 3, 3'- Diaminobenzidine; DMH, di-methylhydrazine; Diac, diacerein; Diacerein; Dll-1, Delta-like 1; ELISA, Enzyme-Linked immunosorbent Assay; EMT, epithelial mesenchymal transition; GSK3-β, glycogen synthase kinase 3- β; H&E, hematoxylin & eosin; HRP, horse-radish peroxidase; Hes-1, hairy enhance of split-1; IL-6; Notch; VEGF, vascular endothelial growth factor; gp130, glycoprotein 130; β-catenin