Role Of Insulin-like Growth Factor-1and ERα In The Anti-breast Tumor Effect Of Wogonin And Influence Of Its On The Angiogenesis And Immune Function

Breast cancer is one of the most common malignant tumors world wide; its incidence is increasing year by year. Breast cancer is the2nd most frequent cause of cancer death in females after cancer of lung. The flavonoid compound wogonin is widely exists in traditional Chinese herbs. Our previous study showed that wogonin could significantly inhibited proliferation of the breast cancer cell line MCF-7. Primary mechanism studies revealed that the compound inhibited MCF-7proliferation through blocking insulin-like growth factor-1(IGF-1)-mediated signal pathway. It is generally regarded that IGF-1R function is closely related to that of ERα. Because ERα plays key roles in IGF-1-mediated signal transduction pathway, it is necessary investigate effect of wogonin on ERα. Aim of the present study is: First, to investigated role of wogonin in IGF-1-mediated signal pathway and its relationship with ERα; Second, to study effect of the compound on angiogenesis, in vivo immuno function and its toxicity. The main results of our paper are as follows:1. Wogonin significantly inhibited agonist effect of IGF-1on MCF-7proliferation. Compared to IGF-1control group, viabilities of the MCF-7cells were greatly decreased in IGF-1+WO+ICI, IGF-1+WO and IGF-1+ICI groups, while viabilities of the MCF-7cells in IGF-1+WO+ICI, IGF-1+ICI and IGF-1+WO groups remained largely unchanged as determined by MTT assay, which manifested that wogonin could significantly inhibited IGF-1-mediated MCF-7cell proliferation, the effect was related to ERα.2. Western blotting analysis was applied for further mechanism studies. It showed that wogonin significantly inhibited agonist effect of IGF-1on MCF-7proliferation. Compared to IGF-1control group, expression of ERα and p-Akt were greatly decreased in IGF-1+WO+ICI, IGF-1+WO and IGF-1+ICI groups, while expression of ERa and p-Ak in IGF-1+WO+ICI, IGF-1+ICI and IGF-1+WO groups remained unchanged. Our primary results proposed that inhibition of IGF-1-mediated PI3K-Akt pathway by wogonin is ERa-dependent. ERα might be a potential molecular target in breast cancer therapy.3. In in vivo study done on6-day-old chick embryo chorioallantoic membrane (CAM) showed that wogonin could significantly inhibit angiogenesis in CAM.4. MTT assay was used to examine the effect of wogonin on T lymphocytes proliferation. Compared to DMSO control, wogonin could dose-dependently inhibit proliferation of T lymphocytes. At60μmol/L, T lymphocytes proliferation was decreased by1.23folds.5. Neutral red phagocytosis method was used in macrophage function study. It showed that wogonin could greatly increase the phagocytic rate of the macrophage. At60μmol/L, phagocytic rate of the macrophage was increased by5.7fold compared to the DMSO control.6. Toxicity of wogonin was evaluated by oral toxicity test, mice bone-marrow micro-nucleus test, sperm malformation test and hemolysis test. No significant toxicities were observed in the test conditions, which further manifested the potential use of wogonin in anti breast cancer therapy.