Elevated MMP-9 level has been shown to positively correlate with invasive and metastatic potentials in hepatocellular carcinoma cells and hypopharyngeal carcinoma.33, 34 In this study, overexpression of miR-375 was verified to reduce the expression of MMP-2 and MMP-9, while miR-375 inhibition led to significant increases in MMP-2 and MMP-9 protein levels, indicating miR-375 may also regulate extracellular matrix degradation in LSCC. This evidence concerns the gene MMP9 and hypopharyngeal carcinoma.