MicroRNA-183 (miR-183) has been demonstrated to be a tumor suppressor miRNA in inhibition of migration and invasion of osteosarcoma by targeting an oncogene Ezrin. The aim of the present study was to determine the correlation of combined miR-183 and Ezrin mRNA expression with clinicopathologic features and prognosis in patients with osteosarcomas. Expressions of MiR-183 and Ezrin mRNA were both examined using quantitative real-time reverse transcriptase-polymerase chain reaction analysis in 68 specimens from patients with osteosarcomas. MiR-183 and Ezrin mRNA expression levels were, respectively, lower and higher in osteosarcoma tissues than those in noncancerous bone tissues significantly (both P < 0.001). Notably, the downregulation of miR-183 was negatively correlated with the upregulation of Ezrin mRNA in osteosarcoma tissues (r = -0.66, P = 0.01). In addition, the combined miR-183 downregulation and Ezrin upregulation (miR-183-low/Ezrin-high) was significantly associated with high tumor grade (P = 0.02), poor response to chemotherapy (P = 0.01), positive metastasis (P = 0.006) and recurrence (P = 0.008). Moreover, miR-183/Ezrin expression and the status of metastasis were both found to be independent prognostic factors for overall survival (P = 0.02 and 0.01, respectively) and disease-free survival (both P = 0.02). Our findings showed that the aberrant expression of miR-183 and its target gene Ezrin may play a crucial role in the development and progression of human osteosarcoma. More interestingly, the dysregulation of miR-183/Ezrin axis may be related to the prediction of aggressiveness and poor prognosis for patients with this lethal disease.

The Kindlin protein family, comprising Kindlin-1, Kindlin-2 and Kindlin-3, play important roles in various human cancers. Here, to explore the clinical significance of Kindlins in human osteosarcomas, quantitative real-time PCR and Western blot analyses were performed to detect the expression of Kindlin-1, Kindlin-2 and Kindlin-3 mRNAs and proteins in 20 self-pairs of osteosarcoma and adjacent noncancerous tissues. Then, immunohistochemistry was performed to examine subcellular localizations and expression patterns of Kindlin proteins in 100 osteosarcoma and matched adjacent noncancerous tissues. Kindlin-1, Kindlin-2 and Kindlin-3 protein immunostainings were localized in the cytoplasm, nucleus and cytoplasm, respectively, of tumor cells in primary osteosarcoma tissues. Statistically, the expression levels of Kindlin-1 and Kindlin-2 mRNAs and proteins in osteosarcoma tissues were all significantly higher (both P<0.01), but those of Kindlin-3 mRNA and protein were both dramatically lower (both P<0.05), than in matched adjacent noncancerous tissues. In addition, the overexpressions of Kindlin-1 and Kindlin-2 proteins were both significantly associated with high tumor grade (both P=0.01), presence of metastasis (both P=0.006), recurrence (both P=0.006) and poor response to chemotherapy (both P=0.02). Moreover, Kindlin-1 and Kindlin-2 expressions were both identified as independent prognostic factors for overall (both P=0.01) and disease-free (P=0.02 and 0.01, respectively) survivals of osteosarcoma patients. However, no associations were observed between Kindlin-3 expression and various clinicopathologic features and patients’ prognosis. In conclusion, aberrant expression of Kindlin-1 and Kindlin-2 may function as reliable markers for progression and prognosis in osteosarcoma patients, especially for tumor recurrence.