Fig. 8

Signal transduction pathways induced by estrogen and heteronemin in ER-positive and -negative breast cancer cells. Estrogen binds to ER-α at the cell surface or integrin αvβ3 receptor in ER-positive or ER-negative breast cancer cells, respectively to activate signal transduction pathways such as ERK1/2 and STAT3. Those signals play vital roles in gene expression involved in cancer cell proliferation and metastasis. In addition. On the other hand, heteronemin suppresses ERK1/2 and STAT3 activation and inhibits the expression of proliferative genes. In addition, heteronemin activates the caspase signal pathway