Downregulation of microRNA-26a is associated with metastatic potential and the poor prognosis of osteosarcoma patients
Authors: Zhi-Bin Shi
Qi-Chun Song
Yong-Tao Zhang
Le Ji
Da-Peng Duan
Xiao-Qian Dang
Kun-Zheng Wang
Journal: Oncology Reports (2014)
Discipline: CLINICAL MEDICINE
Keywords: microRNA-26a; osteosarcoma; tumor suppressor; prognosis; clinical stage
Affiliations: Department of Orthopedics, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, P.R. China., Department of Orthopedics, Shaanxi Provincial People's Hospital, Xi'an, Shaanxi 710068, P.R. China.

Abstract:  Accumulating evidence indicates that microRNAs are involved in multiple processes in cancer development and progression. microRNA-26a (miR-26a) has been identified as a tumor suppressor and its downregulation is associated with poor prognosis in several types of human cancer. However, the specific function of miR-26a in osteosarcoma remains unclear. In the present study, we found that the expression of miR-26a in osteosarcoma tissues and cell lines was much lower than that in the normal controls, respectively. In addition, downregulation of miR-26a more frequently occurred in osteosarcoma specimens with adverse clinical stage and with the presence of distant metastasis. Moreover, multivariate survival analyses demonstrated that loss of miR-26a is an independent prognostic factor for both disease-free and overall survival in osteosarcoma. In addition, restoration of miR-26a expression inhibited the invasion and migration in osteosarcoma cells, and miR-26a directly inhibited enhancer of zeste homolog 2 (EZH2) expression by targeting its 3'-UTR. Moreover, EZH2 was upregulated and inversely correlated with miR-26a expression in the osteosarcoma tissues. Thus, for the first time, we provide convincing evidence that downregulation of miR-26a is associated with tumor aggressiveness and tumor metastasis, and miR-26a inhibits cell migration and invasion by targeting the EZH2 gene in osteosarcoma. Thus, miR-26a is an independent prognostic marker for osteosarcoma patients. 

Retracted: No

PubPeer comments:
 Fig 3 C,D.  I am not convinced that the two marked Migration panels came from different cell-lines. , 
 #1 Dear Camphorifolia, Thank you for your concern. In the original version of this manuscript, We accidentally duplicated the image belonging to MG-63 NC group to U2OS NC group, for unscientific picture naming when we took the photos of the transwell assays. My student named the pictures of MG-63 NC group as N-1, N-2, N-3, etc, and named the pictures of U2OS NC group as N-1, N-1-2, N-1-3. When he was taking the pictures, I pointed out the unscientific naming would lead to confusion in result analysis, and told him the scientific naming method. Thus he use scientific naming method in the following. But he forget to correct the error in NC group naming. So, when we prepare the Figures, we misused N-1 and N-2 as the representative picture for MG-63 and U2OS group. I apologize for the unintentional mistake. Many thanks for your kind reminding, we are very sorry for the erro of the Figure. And we have corrected this and we will send a correction to the journal and expect to publish Erratum soon. We will be more rigorous in the future scientific research work. Thank you for your interest in our work! Sincerely, Dang. encl: Corrected Figure  , 
 I thank the authors for their helpful response. ,