The MicroRNA Express Difference Spectrum Of Liposarcoma By Using Eve-Green Based RT-PCR Microrna Assay

Background and purpose:Soft Tissue Sarcomas is rare, however it contains many histological types, and each type has its own biological behaviors. Liposarcoma is the most common type of Soft Tissue Sarcoma. Liposarcoma is located in the retroperitoneum which makes it can retain for a long time without any clinical syndromes. The most striking feature of liposarcoma is recurrence rapidly, but metastasis is uncommon. According to2002WHO guidelines liposarcoma is classified into five subtypes constituting three biological groups:(1) well-differentiated liposarcoma (WDLPS) and dedifferentiated liposarcoma (DDLPS),(2) myxoid and round cell liposarcoma (MLS/RCLS),(3) pleomorphic liposarcoma (PLS). Well-differentiated and myxoid liposarcoma are low-grade types, whereas dedifferentiated, round cell and pleomorphic liposarcoma are high-grade, aggressive types with metastatic potential. Surgical resection is the cornerstone of potentially curative treatment to date. Complete resection of tumor (negative margins of1-2cm) is associated with optimal outcome, for most of liposarcoma located in retroperitoneum, which makes complete resection hard to achieve. Uncompleted resection is the main cause of recurrence. Chemotherapy and radiotherapy (RT) are used to treat those patients, whose tumor is unresectable or resectable but with positive margins or resectable with negative margins but with risk of significant morbidity. Nonetheless, except MLS/RCLS, liposarcoma is low sensitive to chemotherapy and RT, thus there is of urgently necessity to develop new targeted therapies for liposarcoma patients. MiRNAs are a class of18-24nucleotide RNA molecules that negatively regulate target mRNAs. Dysregulation of miRNAs can influence on cellular differentiation, oncogenesis, tumor invasion, tumor metastasis and tumor recurrent. MiRNAs can function either as tumor suppressors or oncogenes. Accordingly, developing new therapeutic strategies to target tumor-driving miRNAs dysregulation is essential. Review the related literature, the study of relationship between liposarcoma and miRNAs has been rarely reported. In our study, we use Eve-Green based RT-PCR assay to detect the expression of miRNAs of each sample. We used59cases of frozen tissues acquired under an Institution Research Board approved protocol derived from25surgically resected samples. Among these,9cases are well-differentiated liposarcoma,8cases are myxoid and round-cell liposarcoma,8cases are dedifferentiated liposarcoma,18cases of liposarcoma patients’ normal adipose tissue (away from tumor more than5cm), and16cases are the adjacent adipose tissues of tumor (away from tumor within1cm). All liposarcoma cases were diagnosed by pathology. For further research in the future, we need analysis specific miRNA expression differences among different types of liposarcoma and other adipose tissues.Methods:Using Eve-Green based RT-PCR assay to detect the expression of1920miRNAs of each sample. We used59cases of frozen tissues acquired under an Institution Research Board approved protocol derived from25surgically resected samples. Among these,9cases are well-differentiated liposarcoma,8cases are myxoid and round-cell liposarcoma,8cases are dedifferentiated liposarcoma,18cases of liposarcoma patients’ normal adipose tissue (away from tumor more than5cm), and16cases are the adjacent adipose tissues of tumor (away from tumor within1cm). All liposarcoma cases were diagnosed by pathology. Then analysis specific miRNA expression differences among different types of liposarcoma and other adipose tissues. Using Eve-Green based RT-PCR assay to check the expression of some distinguished miRNAs between liposarcoma cell line and normal adipose cell line.Results:The Quantile-Mean method was used to analyze the data. Statistical analysis identifies40miRNAs are significantly (P<0.05, fold change>1.5) overexpressed in liposarcoma as compared with normal adipose tissues, and21miRNAs are downexpressed in liposarcoma. Compared liposarcoma tissues with the adjacent adipose tissues of tumor, there are121miRNAs dysregulation (P<0.05, fold change>2). We find that9miRNAs overexpressed in the adjacent adipose tissues of tumor higher than in normal adipose tissues, and2miRNAs downregulated in the adjacent adipose tissues of tumor (P<0.05, fold change>2). Among WDLPS, DDLPS and MLS/RCLS, there are miRNAs expression differences. Using SVM method, we identified a unique eight-tumor miRNA signature, and verified in two cell lines. Conclusion:In sum, we identified a unique eight-tumor miRNA signature from the whole genome-wide1920miRNAs for LPS detection, implied that these8miRNAs may connect with liposarcoma tumorigenesis and development. We also identified some miRNAs can classify the subtypes of LPS. This work will serve as the basis for future studies about the clinical value of tumor miRNAs in predicting therapeutic efficacy, maintaining surveillance and forecasting prognosis, and pave the way for the understanding of the mechanisms with respect to the distinguish among liposarcoma subtypes.