miR-375 negatively mediates expression of PAX6 protein. (A) Reverse transcription-quantification polymerase chain reaction and (B) western blot analysis were performed to examine levels of PAX6 mRNA and protein in miR-375-upregulating or -downregulating MCF-7 cells. GAPDH was used as an internal reference. **P<0.01 vs. Control. miR, microRNA; PAX6, paired box 6; MCF, Michigan Cancer Foundation; GAPDH, glyceraldehyde 3-phosphate dehydrogenase; Control, non-transfected MCF-7 cells.