Yiqi Huayu Jiedu Decoction inhibits liver metastasis of colorectal cancer via enhancing natural killer cells function

Abstract

Ethnopharmacological relevance: Complementary treatment with valuable efficacy and less toxic or side effect is in urgent need for colorectal cancer (CRC) therapy. Yiqi Huayu Jiedu Decoction (YHJD) is a polyherbal formulation which has been applied in clinic to treat CRC for a long period of time. Nevertheless, the potential active ingredients and molecular mechanism remains to be further explored.

Aim of the study: To probe the effective compounds of YHJD and its underlying pharmacological effects. Moreover, the influence on liver metastasis of CRC as well as function of natural killer (NK) cells results from YHJD was investigated.

Materials and methods: The active ingredients and target genes of YHJD was examined through TCMSP databases. Compound-compound target network was performed by applying Cytoscape3.9.1 software. The CRC-related disease targets were explored via DisGeNET database. Venn database was used to find the common genes between CRC and YHJD. Protein-protein interaction network was established by STRING database. Biological process and signaling pathways potentially regulated by YHJD were evaluated by DAVID database. Western blot assay was then conducted to further investigate the effect of YHJD on PI3K-AKT signaling. The association between NK cells content and TNM or pathological stages of CRC was studied through TCGA database. The killing efficiency of NK cells was researched by CCK8 experiment. In vivo assay and HE staining were performed to assess the anti-liver metastasis effect of YHJD. The variation of NK cells content was authenticated by applying flow cytometry analysis.

Results: We firstly found 176 active ingredients and 268 target genes of YHJD. Compound-compound target network was then established consisted of 455 nodes and 3989 edges. Then 707 disease targets associated with CRC were discovered and 42 common genes between CRC and YHJD were identified. Protein-protein interaction network was further constructed, among which 5 vital genes including TP53, AKT1, TNF, MYC and CCND1 were recognized. GO and KEGG analysis was performed to explore probable biological process and signaling pathways regulated by YHJD. Particularly, the ratio of p-PI3K/PI3K and p-AKT/AKT at protein level representing the activation of PI3K-AKT signaling could be suppressed by YHJD. In addition, bioinformatic analysis detected reduced NK cells content in CRC tissues, which gave rise to more advanced node, metastasis and pathological stages. We next presented that YHJD can improve the killing effect of NK cells on CRC. At meantime, YHJD was capable of suppressing liver metastasis of CRC in vivo as well as promoting the content of NK cells, while the improving effect was partially neutralized by anti-ASGM1.

Conclusions: Our research indicates that YHJD can prohibit liver metastasis of CRC in vivo. The therapeutic effectiveness is linked to regulation of multiple targets and effector process, especially PI3K-AKT signaling as well as immune response dominated by NK cells.

Keywords: Active constituents; Colorectal cancer; Liver metastasis; NK cells; Yiqi Huayu Jiedu decoction.