Background: Soothing the liver (called Shu Gan Jie Yu in Chinese, SGJY) is a significant therapeutic method for breast cancer in TCM. In this study, 3 liver-soothing herbs, including Cyperus rotundus L., Citrus medica L. var. sarcodactylis Swingle and Rosa rugosa Thunb. were selected and combined to form a SGJY herbal combinatory.
The aim of the study: To investigate the inhibiting effect of SGJY on breast cancer in vivo and vitro, and to explore the potential mechanisms.
Materials and methods: SGJY herbal combination was extracted using water. A breast cancer rat model was developed by chemical DMBA by gavage, then treated with SGJY for 11 weeks. The tumor tissue was preserved for RNA sequencing and analyzed by IPA software. The inhibition effects of SGJY on MCF-7 and T47D breast cancer cells were investigated by SRB assay and cell apoptosis analysis, and the protein expression levels of SNCG, ER-α, p-AKT and p-ERK were measured by western blotting.
Results: SGJY significantly reduced the tumor weight and volume, and the level of estradiol in serum. The results of IPA analysis reveal SGJY upregulated 7 canonical pathways and downregulated 16 canonical pathways. Estrogen receptor signaling was the key canonical pathway with 9 genes downregulated. The results of upstream regulator analysis reveal beta-estradiol was the central target; the upstream regulator network scheme showed that 86 genes could affect the expression of the beta-estradiol, including SNCG, CCL21 and MB. Additionally, SGJY was verified to significantly alter the expression of SNCG mRNA, CCL21 mRNA and MB mRNA which was consistent with the data of RNA-Seq. The inhibition effects of SGJY exhibited a dose-dependent response. The apoptosis rates of MCF7 and T47D cells were upregulated. The protein expression of SNCG, ER-α, p-AKT and p-ERK were all significantly decreased by SGJY on MCF-7 and T47D cells.
Conclusion: The results demonstrate that SGJY may inhibit the growth of breast cancer. The mechanism might involve downregulating the level of serum estradiol, and suppressing the protein expression in the SNCG/ER-α/AKT-ERK pathway.
Keywords: IPA analysis; RNA-SEQ; SNCG/ER-a/AKT-ERK pathway; Shu Gan Jie Yu combination (SGJY); breast cancer.