RNA binding protein HuR promotes osteosarcoma cell progression via suppressing the miR-142-3p/HMGA1 axis

The present study aimed to study the roles and underlying mechanisms of human antigen R (HuR) in osteosarcoma (OS) cell progression. It was determined that the HuR mRNA and protein levels were significantly upregulated in OS tissues, compared with that in normal adjacent tissues. HuR expression was negatively associated with miR-142-3p expression, but positively with High Mobility Group AT-Hook 1 (HMGA1). Additionally, knockdown of HuR inhibited OS cells viability, epithelial-mesenchymal transition and promoted cell apoptosis. HuR was determined to harbor binding sites on HMGA1, directly binding to HMGA1, increasing HMGA1 mRNA stability and expression. Notably, the promotion of HuR on HMGA1 expression was attenuated via miR-142-3p overexpression, and miR-142-3p could directly bind to HMGA1 3'untranslated region (UTR). Furthermore, HMGA1 3'UTR with a mutated miR-142-3p binding site did not respond to HuR alterations. Finally, the inhibition of HuR knockdown was attenuated or even reversed via HMGA1 overexpression; therefore, the results of the present study indicated that RNA binding protein HuR may facilitate OS cell progression via competitively binding to HMGA1 with miR-142-3p.