Background: Laryngeal cancer (LC) is one of the common malignant tumors in the head and neck area, and the survival rate for patients is low.
Objectives: To investigate miR-122a and miR-3195 expressions in LC tissue, their correlations with clinicopathological features, and their impacts on Hep-2 proliferation and apoptosis.
Material and methods: Thirty LC and 20 peritumoral tissue specimens were analyzed. miR-122a, miR-122a-negative control sequence, miR-3195, and miR-3195-NG sequence were transfected into Hep-2 in the miR-122a-mimics, miR-122a-NG, miR-3195-mimics, and miR-3195-NG groups, respectively. The miR-122a-mimics-non-transfected and miR-3195-mimics-non-transfected groups used non-transfected Hep-2.
Results: There were lower miR-122a, miR-3195 and occludin protein, and higher TBX1 protein expressions in LC than in the peritumoral tissue; the miR-122a level was associated with clinical stage (all p < 0.001). Positive correlations between miR-122a and miR-3195, and miR-122a and occludin expressions, and a negative correlation between miR-3195 and TBX1 expressions were observed (r = 0.418, r = 0.541, r = -0.428, all p < 0.001). The miR-122a and miR-3195 levels in the 2 mimics groups increased respectively compared to their NG and the non-transfected groups. At different time points after 24 h of transfection, the optical density in the 2 mimics groups was lower than in their NG groups. The miR-122a-mimics group had an increased occludin level and the miR-3195-mimics group had a decreased TBX1 level, and both groups had greater apoptosis rates than their NG groups and in the non-transfected groups (all p < 0.001).
Conclusions: miR-122a is associated with clinical stage. miR-122a and miR-3195 may act as tumor suppressors and play a role in LC pathogenesis. They can suppress Hep-2 proliferation and promote its apoptosis, probably owing to the upregulation of occludin by miR-122a and suppression of TBX1 by miR-3195.
Keywords: apoptosis; cell proliferation; laryngeal neoplasms; microRNAs.