MACC1 is a direct target of miR-338-3p. (A) Putative binding sites of miR-338-3p within the 3′-UTR region of MACC1 mRNA and the sequences of wild-type and mutant-type vector. (B) The relative luciferase activities were inhibited in A375 and G361 cells co-transfected with wild-type MACC1 3′UTR vector and miR-338-3p mimic, not with the mutant-type vector. Firefly luciferase activity was normalized to Renilla luciferase. Data are presented as the mean value ± standard deviation from triplicate experiments. **P<0.01 vs. miR-NC; (C) The protein level of MACC1 was detected by western blotting in A375 and G361 cells transfected with miR-338-3p mimics or miR-NC. (D) The relative expression levels of MACC1 mRNA in MM tissues and adjacent tissues were detected by quantitative polymerase chain reaction. ***P<0.001. (E) The Pearson's correlation analysis for the association between miR-338-3p levels and MACC1 mRNA levels in MM tissues. miR, microRNA; NC, negative control; MM, malignant melanoma; UTR, untranslated; Mut, mutant; Wt, wild-type; MACC1, metastasis-associated in colon cancer-1.