Prediction of the Que target genes
The chemical structure of Que was obtained from the PubChem database, as shown in Fig. 2A. Based on its structure, the PharmMapper database, TCMSP database, and Swiss Target Prediction database were used to predict the potential target genes of Que. The targets obtained from these databases were combined. Duplicates were removed to obtain 482 potential target genes.
Prediction of precancerous lesions of breast cancer-related que target genes by a systematic pharmacology approach
Information on a total of 1602 disease target genes associated with breast cancer lesions were obtained in the GeneCards database (https://www.genecards.org/) when the keywords "precancerous lesions" were used. Intersecting 482 potential target genes of Que with 1602 disease targets resulted in 314 genes, as shown in Fig. 2B, and these target genes were not only precancerous lesion-related genes but also drug targets. The PPI network graph of the target contained 157 nodes and 589 edges, in which the nodes represent targets and the edges represent the interaction between targets. The PPI data were imported into Cytoscape 3.6.1 software for visualization. As shown in Fig. 2C, the top 20 targets for the degree value of the target were MAPK1, SRC, HRAS, AKT1, HSP90AA1, MAPK8, RHOA, MAPK14, ESR1, EGFR, IGF1, RXRA, JAK2, CASP3, AR, PTK2, IL-2, STAT1 and MMP9.
Functional enrichment analysis for the Que target genes
To explore the relationship between these 314 potential target genes, GO and KEGG enrichment analyses were performed using the STRING database. A variety of GO enrichment terms were enriched, including 1980 biological processes, 100 cellular components, and 223 molecular functions. We found that biological processes such as cellular process and metabolic process, cellular components such as binding and catalytic activity, and molecular function such as cell and intracellular (Fig. 2D) were enriched, which may be involved in the biological activity of the Que treatment process. In addition, 176 KEGG pathways were enriched (Fig. 2E). Among the major Que-related pathways identified by KEGG, the pathways were mainly associated with the cancer pathway and PI3K-Akt signaling pathway; however, JAK/STAT1 signaling pathway ranked fourth among the pathways screened for immunity to Que (Fig. 2F). It has been suggested that Que may improve the progression of breast cancer from precancerous lesions to breast cancer or improve the prognosis of breast cancer patients through the JAK/STAT1 signaling pathway.
Cell proliferation experiments in MCF-10AT, MCF-7 and MDA-MB-231 cells
The effects of Que on the proliferation of MCF-10AT, MCF-7 and MDA-MB-231 cells were determined by an MTT assay, and the results are shown in Fig. 3D. The half maximal inhibitory concentration (IC50) values of Que on MCF-10AT, MCF-7 and MDA-MB-231 cells were 52.39 µM, 53.76 µM and 64.23 μM, respectively.
Apoptosis of MCF-10AT, MCF-7 and MDA-MB-231 cells was induced by Que at different concentrations at different time periods
To evaluate the proapoptotic properties of Que on induced cell death, we performed an Annexin-V binding assay and made compensation-related errors (Fig. 3A). We detected the apoptosis of MCF-10A, MCF-10AT, MCF-7, MDA-MB-231 cells treated with Que at 5 μM, 20 μM, 80 μM, and 120 μM at 24 h and 48 h (Fig. 3B and C). First, mammary gland cells were treated with Que for 24 h. We compared MCF-10AT with MCF-10A, MCF-7 and MDA-MB-231 cell lines at a Que concentration of 5 μM. The percentage of the total apoptotic cell population was determined to be 2.85 ± 0.21% and 3.27 ± 0.14%, 2.84 ± 0.21%, and 2.85 ± 0.21% (P = 0.006, P = 0.109, and P = 0.004, respectively), and the difference was statistically significant. MCF-10AT cells were compared with MCF-10A, MCF-7, MDA-MB-231 cell lines treated with 20 μM Que. The percentage of the apoptotic cell population was 7.60 ± 0.21% and 3.31 ± 0.12%, 12.76 ± 0.37%, and 20.17 ± 2.90% (P = 0.004, P = 0.002, and P = 0.004, respectively). There was a significant statistical difference. MCF-10AT cells were compared with MCF-10A, MCF-7, and MDA-MB-231 cells treated with 80 μM Que. The percentage of the apoptotic cell population was 35.63 ± 0.60% and 1.64 ± 0.05%, 25.34 ± 5.06%, 29.80 ± 0.98% (P = 0.002, P = 0.004, P = 0.004, respectively), which showed statistical significance. MCF-10AT cells were compared with MCF-10A, MCF-7 and MDA-MB-231 cell lines treated with 120 μM Que. The percentage of the apoptotic cell population was 40.25 ± 0.71% and 3.40 ± 0.07%, 29.38 ± 2.50%, and 29.40 ± 2.51% (P = 0.002, P = 0.002, and P = 0.002, respectively), with statistical significance. Next, MCF-10AT was compared with MCF-10A, MCF-7, MDA-MB-231 cell lines at 5 μM concentration of Que, the percentage of apoptotic cell population was determined as 1.75 ± 0.33% and 1.34 ± 0.15%, 9.63 ± 1.70%, 9.58 ± 0.32% (P = 0.240, P = 0.004, and P = 0.004, respectively). MCF-10AT was compared with MCF-10A, MCF-7, MDA-MB-231 cell lines at 20 μM concentration of Que and percentage of the apoptotic cell population was determined as 8.44 ± 1.54% and 0.84 ± 0.10%, 11.12 ± 1.38%, 14.23 ± 1.62% (P = 0.004, P = 0.016, and P = 0.004, respectively) with significant statistical differences. MCF-10AT was compared with MCF-10A, MCF-7 and MDA-MB-231 cell lines at 80 μM Que, and the percentage of apoptotic cell population was determined to be 72.36 ± 1.77% and 3.52 ± 0.14%, 61.95 ± 1.22%, 74.73 ± 0.77% (P = 0.004, P = 0.004, and P = 0.009, respectively) with statistical significance. MCF-10AT was compared with MCF-10A, MCF-7, MDA-MB-231 cell lines at 120 μM concentration of Que, the percentage of apoptotic cell population was determined to be 79.19 ± 1.76% and 5.52 ± 0.30%, 61.95 ± 1.22%, 74.37 ± 0.80% (P = 0.004, P = 0.004, and P = 0.002, respectively) with significant statistical differences (Fig. 3E). These results indicate that Que can induce apoptosis in MCF-10AT (precancerous breast cancer cells) and MCF-7, MDA-MB-231 (breast cancer cells) at different periods and at different doses in a time- and concentration-dependent manner. However, Que has a stronger apoptosis effect on MCF-10AT cells with precancerous breast cancer lesions but less or even no effect on MCF-10A cell apoptosis. Apoptosis rates at different concentrations at 24 h and 48 h are shown in Fig. 3F.
Que promotes γδ T cell amplification
In vitro induction of peripheral blood mononuclear cells from healthy volunteers in complete medium containing TCR γδ monoclonal antibody and cytokine IL-2 was performed. After adding 0 μM, 2.5 μM, 5 μM, and 10 μM Que on Day 3, the cell morphology was observed under a microscope, and the proportion of γδ T cell subsets was determined by flow cytometry after 10–12 days. We found that the number of γδ T cells increased after Que treatment each day in vitro. Flow cytometry analysis showed that γδ T cells could be effectively amplified with more than 60% purity. γδ T cells expanded to 90% at concentrations of 2.5 μM to 5 μM. Vδ2 T cell subsets were dominant at 2.5 μM Que, Vδ1 T cell subsets were dominant at 5 μM Que, and Vδ2 T cell killing subsets were dominant at 10 μM Que (Fig. 4A). Different concentrations of Que had no significant difference in γδ T cells and their Vδ2 T subsets but had a significant difference in Vδ1T cell subsets (P = 0.40, P = 0.08, and P = 0.04, respectively) (Fig. 4B). These results indicate that γδ T cells have improved killing and immunomodulatory effects.
Cytotoxicity of healthy human γδ T cells against MCF-10A, MCF-10AT, MCF-7, MDA-MB-231 cell lines
After amplification in vitro, the effector cell: target cell (E/T) ratio was 10:1, the killing rates of γδ T cells against MCF-10A, MCF-10AT, MCF-7, and MDA-MB-231 cells were 61.44 ± 4.70, 55.52 ± 3.10, 53.94 ± 2.74, and 53.28 ± 1.73 (P = 0.114, P = 0.486, and P = 0.343, respectively) (Fig. 4C), and the trend was 10:1 > 5:1 > 1:1. There was no significant difference between the groups. These results indicate that γδ T cells have a certain killing effect on both precancer and breast cancer cells.
Que and γδ T cells have synergistic cytotoxic effects on mammary gland cells
To investigate the killing effect of Que and γδ T cells on mammary gland cells, we used 5 μM Que to detect E/T (1:1, 5:1, 10:1) and investigate the specific killing effect. We found that the cell killing rates of MCF-10A cells in E/T (1:1, 5:1, 10:1) were 24.12 ± 4.34, 51.93 ± 6.47, 64.94 ± 3.61. The cytotoxicity rates of MCF-10AT in E/T (1:1, 5:1, 10:1) were 19.38 ± 5.30, 33.45 ± 5.49, 64.96 ± 5.45, and MCF-10A > MCF-10AT (P = 0.222, P = 0.008, and P = 0.917, respectively). The cell killing rates of MCF-7 at E/T (1:1, 5:1, 10:1) were 13.23 ± 2.68, 24.39 ± 3.13, 55.59 ± 5.98, compared with MCF-10AT, the killing rate of MCF-7 versus MCF-10AT was statistically significant at 5:1 (P = 0.095, P = 0.032, and P = 0.056, respectively). The cell killing rates of MDA-MB-231 cells at E:T ratios of 1:1, 5:1, and 10:1 were 12.77 ± 3.64, 22.7 ± 1.39, and 59.04 ± 5.67, respectively. Thus, compared with MDA-MB-231 cells, MCF-10AT cells were also statistically significant at a 5:1 ratio (P = 0.056, P = 0.016, and P = 0.222, respectively). In addition, with the increase in effector cell proportion, the Que concentration was still 5 μM, and MCF-10A > MCF-10AT > MCF-7 > MDA-MB-231, 1:1 < 5:1 < 10:1 (Fig. 4D). These results indicate that Que combined with γδ T cells had a specific killing effect on both precancerous breast cancer cells and breast cancer cells. The strongest killing effect on precancerous breast cancer cells and breast cancer cells was found when the Que concentration was 5 μM and E/T (10:1).
Effect of Que on IFNγ-R, phospho-JAK2 (p-JAK2), phospho-STAT1 (p-STAT1) and PD-L1 in MCF‐10AT and MCF-7 cell line protein expression
Western blotting of IFNγ-R, p-JAK2, p-STAT1 and PD-L1 protein was performed. MCF-10AT and MCF-7 cells were treated with different concentrations of Que at 0 μM, 5 μM, 20 μM, 80 μM and 120 μM for 48 h. Our results showed that when MCF-10AT and MCF-7 cells were treated with Que at 80 μM and 120 μM, respectively, IFNγ-R protein levels and p-JAK2 and p-STAT1 phosphorylation were significantly increased (P < 0.0001), while PD-L1 protein levels were decreased (P < 0.0001, P = 0.0005) (Fig. 5A and B).