Cytomechanical And Cytobiological Study Of Pathological Osteogenic Differentiation Induced By Bone Metastasis Of Prostate Cancer Cells

Objective: To establish a biomechanical biological model of bone metastasis of prostate cancer by applying mechanical load to pre-osteoblast cells cultured in conditioned medium.The differential expression of m RNA and miRNAs in pathological osteogenic differentiation cells induced by bone metastasis of prostate cancer was screened.The signal molecules and signaling pathways associated with pathological osteogenic differentiation were predicted by screening.To predict the molecular target of pathological osteogenic differentiation or bone formation caused by bone metastasis of prostate cancer cell,and to explore the mechanism of pathological osteogenic differentiation caused by bone metastasis of prostate cancer.Methods: MC3T3-E1,a mouse pre-osteoblast cell,was cultured in the conditioned medium of prostate cancer PC-3 cells.The osteoblast cells were subjected to cyclic mechanical loading of 2500 ?? by a four-point bending loading device,considering as the pathological osteogenic differentiation group(pathological group);Applying the cyclic load of 2500 ?? to the untreated pre-osteoblast cells,as the physiological osteogenic differentiation group(physiological group),the relative osteogenic differentiation index was detected,to establish a cell model of pathological osteogenic differentiation induced by bone metastasis of prostate cancer.3.The Digital Gene Expression Tag Profiling was used to screen differential expression of miRNAs in physiological group and physiological group,and the results was verified by qRT-PCR.4.The Digital Gene Expression Tag Profiling were sequenced to screen differentially expressed m RNAs in physiological and pathological groups,Gene Cluster Analysis,GO and KEGG was used to analyze the differentially expressed m RNAs.To screen genes and key signaling pathways related to pathological osteogenic differentiation induced by bone metastases of prostate cancer,and to predict molecular targets and signal pathways related to pathological osteogenesis.Results: 1.Compared with physiological group,the activity and staining of ALP,the expression of osteogenic differentiation related gene /protein(Runx-2 I collagen,OCN)were down-regulated in pathologicalgroup(P<0.05).Compared with physiological group,the real-time fluorescence quantitative PCR showed 7 miRNAs up-regulated and 12 miRNAs down-regulated in pathological group(P<0.05),and was consistent with sequencing results.Go database analysis and KEGG Pathway analysis showed that the genes and the key signaling pathways might be related to pathological osteogenic differentiation induced by bone metastasis of prostate cancer.Conclusion: The MC3T3-E1 cells cultured in conditioned medium of PC-3 under physiological mechanical loading inhibit the osteogenic differentiation,and we establish a biomechanical biological model of bone metastasis of prostate cancer.7 up-regulated miRNAs and 12down-regulated miRNAs may play an important role in osteogenic differentiation of prostate cancer bone metastases.The distribution and significance of genes and signal pathways in GO and KEGG categories during osteogenic differentiation of prostate cancer bone metastases were obtained.It is suggested that the signal pathway and related genes may be related to pathological osteogenic differentiation caused by bone metastasis of prostate cancer.