Fig. 8

MBNL1 negatively regulates STAT3 activity. A and B Tsc2 − / − and Tsc1 − / − MEFs were transduced with a lentiviral vector expressing MBNL1 (Lv-MBNL1) or empty vector alone (Lv). C Tsc2 + / + and Tsc1 + / + MEFs were infected with lentiviruses expressing shRNAs targeting MBNL1 (shMBNL1-2) or a non-targeting shRNA (shSc). A and C Cell lysates were subjected to immunoblotting with the indicated antibodies. B The expression of STAT3 in the indicated cells was analyzed by an immunofluorescence assay. Scale bar, 20 μm. D and E Xenograft tumor tissues derived from the indicated cells were subjected to immunoblotting. F Schematic illustration of the STAT3/miR-130b-3p/MBNL1 feedback loop downstream of mTORC1 signaling promotes tumor angiogenesis