MiR-145 functions as a tumor suppressor in Papillary Thyroid Cancer by inhibiting RAB5C

Papillary thyroid carcinoma (PTC) accounts for the largest proportion of thyroid cancers; and its morbidity rate has dramatically increased in recent decades. However, the pathogenesis mechanisms of PTC are still not clear. This study aimed to reveal that miR-145 acts as an antitumor miRNA in the progression of PTC. In the present study, the expression of miR-145 was analyzed in 57 paired PTC patient samples. The relationship between clinicopathological features and miR-145 expression were also defined. The tumor suppressive function of miR-145 on PTC cell metastasis, proliferation and apoptosis were revealed in vitro. Also, we used dual luciferase reporter assay to define the relationship of miR-145 and RAB5C. RAB5C was reported to participate in cell invasion and cell motility. We found that miR-145 was downregulated in PTCs, which was negatively correlated with PTC progression and metastasis. MiR-145 inhibited PTC migration, proliferation and promoted apoptosis by directly suppresing RAB5C. In conclusion, miR-145 functions as a tumor suppressor in PTC by inhibiting RAB5C. MiR-145 and RAB5C are potential therapeutic targets in therapy of aggressive PTC cases.