Fig. 5

Advances of the STAT3 signaling pathways involving breast cancer chemoresistance. Classical IL-6/JAK/STAT3 pathways can induce chemoresistance in breast cancer, while miR-4532 may attenuate this effect by inhibiting HIC-1 and IL-6/STAT3 pathways. Leukemia inhibitory factor (LIF) binding to its receptor LIFR can increase the activation of STAT3. STAT3 and pSTAT3 levels are regulated by GRP78. Then, phosphorylated STAT3 activates cellular molecules including FAO, CPT1B and MAPK/AKT to induce the chemoresistance of breast cancer. Oct-4 and c-Myc form a signaling loop to promote STAT3/NF-κB activation and chemoresistance in breast cancer. Additionally, miR-124 can inhibit HIF-1 and promote breast cancer chemoresistance