Proteomic study of medicinal mushroom extracts reveals antitumor mechanisms in an advanced colon cancer animal model via ribosomal biogenesis, translation, and metabolic pathways

Abstract

Introduction: Colorectal cancer ranks as the third most common cancer in both men and women, with approximately 35% of cases being stage IV metastatic at diagnosis. Even with treatment advancements, the survival rates for these patients remain suboptimal. There is a significant focus on developing multi-targeted therapies due to the common issue of drug resistance in standard and targeted cancer treatments. Medicinal mushrooms, both as single compounds and as complex extracts, have undergone extensive research. Numerous types of mushrooms have been shown to be safe, effective inhibitors of cancer pathways and strong enhancers of the immune system.

Methods: In this study, we performed both qualitative and quantitative proteomic analyses using tandem mass tags (TMT) on CT26 wild type (CT26. WT) colon cancer tissues from Balb/c mice, which were treated with a special blend of medicinal mushroom extracts, either alone or in combination with the chemotherapy drug 5-fluorouracil.

Results: The results showed a notable increase in survival rates and indicated that medicinal mushroom preparation Agarikon Plus, both alone and combined with 5-fluorouracil or another medicinal mushroom preparation Agarikon.1, impedes multiple key processes in colorectal cancer progression. The analysis of differentially expressed proteins in treated groups was done by use of bioinformatics tools and a decrease in ribosomal biogenesis (e.g., RPS3) and translation processes (e.g., RPL14) as well as an increase in unfolded protein response (e.g., DNAJC3), lipid metabolism (e.g., ACOT7), and the tricarboxylic acid cycle (e.g., FH) were observed.

Conclusion: The treatment induced various alterations of known biomarkers and protein clusters critical to the progression and prognosis of colorectal cancer, laying a promising foundation for further translational research on this treatment modality.

Keywords: cancer metabolism; colorectal cancer; medicinal mushrooms; proteomics; translation; unfolded protein response.

FIGURE 1

Kaplan-Meier survival curves of mice bearing CT26 WT tumors in different treatment groups.

FIGURE 2

Effect of Agarikon Plus (AP), Agarikon.1 (AG), 5-fluorouracil (5-FU), and their combination on tumor volume. Treatment started 14 days after s.c. inoculation of CT26 WT (1 × 10⁶/mouse) cells with 1,200 mg/kg of Agarikon 1 by oral gavage for 14 days continuously, or with 5-FU intraperitoneally at dose of 30 mg/kg on days 1–4. and 15 mg/kg on 6, 8, 10, and 12 day of treatment. Volumes were determined once weekly for 6 weeks. *p <; 0.05; **p < 0.01; ***p < 0.001, versus control group. Bars show means ± SEM.

FIGURE 3

Protein-protein interaction networks identified using STRING for differential proteins in abundance. Different line colors represent the types of evidence for association. Gene names are shown. (A) AP group up-accumulated proteins, (B) AP group down-accumulated proteins, (C) combinatorial group (AP with 5-FU) group up-accumulated proteins, (D) combinatorial group (AP with 5-FU) down-accumulated proteins, (E) combinatorial group (AP with AG) up-accumulated proteins, and (F) combinatorial group (AP with AG) down-accumulated proteins, (G) 5-FU group up-accumulated proteins, (H) 5-FU group down-accumulated proteins.

FIGURE 4

Representative Western blot and relative expression of Acot7, Fh, Rps3, Dnajc3, and Apoa2 in tumor tissues from control and four treated groups of animals (each group included tumors obtained from two mice). Results are presented as relative expression ±SEM measured in two biological replicates run in technical duplicates. Statistically significant changes (ANOVA, p < 0.05) are marked with an asterisk. C, control group of animals; AP, Agarikon Plus; AP + 5-FU, Agarikon Plus and 5-fluorouracil, AP + AG, Agarikon Plus and Agarikon.1; 5-FU, 5-fluorouracil.