Jolkinolide B inhibits proliferation or migration and promotes apoptosis of MCF-7 or BT-474 breast cancer cells by downregulating the PI3K-Akt pathway

The diterpenoids extracted from Euphorbia kansui S.L. Liou ex S.B.Ho, Euphorbia fischeriana Steud. have good antitumor effects. Jolkinolide B has anti-breast cancer effect, but it is unclear whether it has different therapeutic effects between luminal A subtype and luminal B subtype breast cancer.This study investigated the Jolkinolide B has different therapeutic, important targets and pathways effects between luminal A subtype and luminal B subtype breast cancer.We used bioinformatics to predict the biological process and molecular mechanism of Jolkinolide B in treating two types of breast cancer. Then, in vitro, cultured MCF-7 cells and BT-474 cells were divided into control group, PI3K inhibitor + control group, Jolkinolide B group and PI3K inhibitor + Jolkinolide B group. The CCK-8 assay, Flow cytometric analysis and Transwell cell migration assay was used to detect the cell proliferation, apoptosis, and migration in each group, respectively. ELISA was used to measure the content of Akt and phosphorylated Akt (p-Akt) in cell lysis buffer.Compared to luminal A breast cancer, Jolkinolide B had more targets, proliferation, migration processes and KEGG pathways when treating luminal B subtype breast cancer. Jolkinolide B significantly prolonged the survival time of luminal B subtype breast cancer patients. Compared to the control group, the cell proliferation absorbance value (A value) and migration number of the two kinds of breast cancer cells in the Jolkinolide B group were decreased (P < 0.01, n = 6), and the number of apoptotic cells was increased (P < 0.01, n = 6). Compared to the Jolkinolide B group, the A value and migration number of the two types of breast cancer cells were significantly decreased in the PI3K inhibitor + Jolkinolide B group (P < 0.01, n = 6), and the number of apoptotic cells was significantly increased (P < 0.01, n = 6). In addition, compared to MCF-7 cells, the A value and migration number of BT-474 cells stimulated with Jolkinolide B were significantly decreased (P < 0.01, n = 6), and the number of apoptotic cells was significantly increased (P < 0.01, n = 6). Akt and p-Akt protein levels in the two breast cancer cell lines in the Jolkinolide B group were all decreased (P < 0.01, n = 6), especially in BT-474 cells stimulated by Jolkinolide B.Jolkinolide B regulates the luminal A and luminal B subtypes of breast cancer through PI3K-Akt, EGFR and other pathways. Jolkinolide B has more significant therapeutic effect on luminal B subtype breast cancer. In vitro, experiments verified that Jolkinolide B significantly inhibited the proliferation and migration activity of BT-474 breast cancer cells by downregulating the PI3K-Akt pathway.