The Mechanism Of PRAME In Regulating Lung Cancer Bone Metastasis

Objective:Lung cancer is the most common diseases and 30%~40% lung cancer patients develop bone metastasis.It has been a social health problem now.Melanoma specific antigen(Preferentially expressed antigen of melanoma,PRAME)is in many melanoma screening in patient group,it is a kind of surface antigen,cytotoxic T lymphocytes can identify PRAME,dissolve immediately cause the correlation of specific tumor.At present,the research has identified PRAME can act as a judge the prognosis of patients with cancer and recurrence of important indicators,PRAME in primary osteosarcoma,squamous cell carcinoma of the skin,such as tumor also herald cancer that has spread to the performance of the high or low in the case.In order to clarify the role of PRAME in the metastasis of lung cancer and its regulation of downstream gene signaling pathway,we designed this study,which I think is very initial.methods1.The expression of PRAME in normal lung tissue,lung cancer in situ and lung cancer bone metastases.Specimens of human lung cancer in situ,bone metastasis and normal lung tissues were gained and we used Western-Bloting and qRT-PCR to compare the expression of PRAME with one another.So that we can get the conclusion.2.Experiments in vitro to clarify PRAMEs expression in lung cancer bone metastasis.we transfected PC9 and A549 Cell linesof lung adenocarcinoma with PRAME siPRAME to knock down the PRAME's expression.we used The Invasion assay and MTT assay to evaluate the change of cell metastasis and migration after transfection,and as the expression of E-cadherin is related to cell migration,we also measured them by the methods: western blot and qRT-PCR.3.Experiments on mouse model to clarify PRAMEs expression in lung cancer bone metastasis.Established the mouse model of tibial bone metastasis using the PC9 cell lines via intraosseous injection.Detect the PRAME gene expression and E-cadherin using immunohistological staining,and evaluate the tumor model by X-Ray and IVIS.Results1.The expression of PRAME in normal lung tissue,lung cancer in situ and lung cancer bone metastases.The Western-Bloting results all showed that not only lung cancer tissures but also normal lung tissues expressed PRAME which was obvious higher for the later.The lung cancer tissures also showed a obviously lower level of PRAME mRNA as we found.So was the similiar trend of E-cadherin m RNA in lung cancer bone metastasis tissures.2.Experiments in vitro to clarify PRAMEs expression in lung cancer bone metastasis.It was proved by the obvious lower level of expression of PRAME protein and PRAME mRNA detected by qRT-PCR and western blot respectively that the knock down of PRAME through siPRAME transfecting absolutely succeeded.The Inviasion assay and the MTT assay showed an obviously high cell migration of the transfected cells in the two lines.At the same time E-cadherin protein expression levels and PRAME genes were positively correlated.3.Experiments on mouse model to clarify PRAMEs expression in lung cancer bone metastasis.The bone erosion phenomenon is founded more obvious in SiPRAME than in SiN by X-Ray and IVIS.The tumor immunohistological staining also indicates that the PRAME genes expression in SiPRAME group was obviously lower,at the same time,E-cadherin protein expression level is obviously reduced.ConclusionFrom all above,It is found that the PRAME were able to be expressed in both lung cancer bone metastasis and normal lung tissues while the latter had a higher expression.We also demonstrated that knocking down the PRAME will promote migration and metastasis of the E-cadherin,which in turn decrease the migration related genes' expression.