Identification Of MiRNAs That Are Associated With Tumor Metastasis In Neuroblastoma And Tumorigenesis In Osteoblastoma

The discovery of microRNAs (miRNAs) has opened a new avenue for both diagnosis and treatment of cancers. Accumulating experimental evidences indicate that miRNAs are aberrantly expressed in different tumor types and have a critical role in tumorigenesis. However, the miRNAexpression profile in neuroblastoma (NB), one of the most common cancer forms in children, has not been well characterized. In the present study, we established a heterotopic transplant mice model of NB and employed miRNAmicroarray analysis to identify miRNAs that are differentially expressed in metastatic NB compared to primary NB. Alist of54miRNAs was found to be significantly altered in metastatic tumors compared to primary tumors. These differentially-expressed miRNAs were selectively validated by a stem-loop qRT-PCR assay. Furthermore, we predicted a list of potential miRNA-target pairs that may be involved in the metastasis of neuroblastoma by three different computer-aided algorithms. Taken together, our results indicate that a unique panel of miRNAs are associated with metastatic NB and these differentially-expressed miRNAs may play an important role in the NB metastatic process. This finding may also shed light in our understanding of the nature of metastatic NB and provide a potential novel target for therapeutic treatment of this tumor.The second project, we collaborate with Nanjing General Hospital of Nanjing Military Region to collection tumor tissue samples and blood samples of Osteosarcoma(OS) patients. From3/2008to present we have collection53samples tissue and nearly one hundred blood samples. By using microArray,we investigated the microRNA expression profile in tumor tissue samples. The significance of difference changed microRNA also been validated by real-time qRT-PCR in all tissue samples. We find that there are63microRNAs significant changed in tumor tissue samples relative to normal control samples. This result indicate that the cluster of significant changed microRNAs could be play a role in OS tumorigenesis. The most significant down-regulate microRNA(miR-199a-5p) in tissue samples was selected to study on OS cell-lines(MG-63cell line). Overexpression of miR-199a-5p in MG-63cell line by transfection hsa-miR-199a-5p mimic, we investigate the proliferation, apoptosis, migration&invasion and differentiation by MTT, flow cytometry, transwell, immunocytochemistry respectively. We found that overexpression of miR-199a-5p can reduce MG-63proliferation、 migration, and enhance apoptosis、differentiation. All of this results indicate that has-miR-199a-5p could be a potential target gene of Osteosarcoma therapy.