Low concentration of δ-T3 enhanced the anti-cancer effects of Gemcitabine (GEM) on bladder cancer cell growth.

<p>(A) T24 and 5637 cells were incubated for 48 h in the presence of 25 μM δ-T3 and/or 0.08 μM GEM. Then, the percentage of cell viability was determined by MTT assay. (B) T24 and 5637 cells were cultured for 48 h in the absence or presence of 25 μM δ-T3 and/or 0.08 μM GEM, respectively. Apoptotic rates were analyzed by Annexin V/PI staining assay. (C) Combined treatment with GEM (0.08 μM) and δ-T3 (25 μM) for 14 days completely eliminated the colony formation capacity of T24 cells. (D) Western blotting analysis of the apoptosis-related and STAT3 signaling-related protein levels in T24 cells, treated with δ-T3 and/or GEM for 48 h. (E) Western blotting analysis of the STAT3 signaling-related protein levels in T24 cells, treated with δ-T3 and/or GEM for 24h. **, <i>P</i> < 0.01; ***, <i>P</i> < 0.001.