Fig. 4

miR-32-5p promotes multidrug resistance. a-d Elevated or reduced expression of miR-32-5p induces or inhibits resistance to 5-FU, OXA, GEM, and sorafenib in vitro. siPTEN enhances, whereas PTEN-expressing vector reverses the resistance to 5-FU, OXA, GEM, and sorafenib. Ectopic expression of PTEN in Bel7402 cells transfected with miR-32-5p mimics rescues the resistance to 5-FU, OXA, GEM, and sorafenib, while inhibition of PTEN in Bel/5-FU cells transduced with miR-32-5p inhibitor reverses the inhibition of 5-FU, OXA, GEM, and sorafenib. WM sensitizes Bel/5-FU cells to 5-FU, OXA, GEM, and sorafenib, but miR-32-5p mimics or siPTEN increases multidrug resistance. n = three independent experiments, *p < 0.05, **p < 0.01, ***p < 0.001 by Student’s t-test or one-way ANOVA test. e Growth curves of xenograft tumors derived from Bel7402 cells injected with agomiR and Bel/5-FU cells injected with antagomiR in response to 0.9%NS or 5-FU. *p < 0.05, by one-way ANOVA test. 0.9%NS, 0.9% normal saline. f, h IHC staining for Ki67, PTEN, p-Akt, p-mTOR, and p-P70S6K in xenograft tumors; original magnification, 400×; scale bar, 25 μm. p-Akt, phosphorylated Akt; p-P70S6K, phosphorylated P70S6K; p-mTOR, phosphorylated mTOR. g The expression of miR-32-5p in xenograft tumors by real-time PCR. The expression of miR-32-5p is normalized to the level of the corresponding internal control U6. *p < 0.05, **p < 0.01 by Student’s t-test