OBJECTIVE: To study the changes in patterns of gene expression exhibited by @entity1 chondrocytes as they dedifferentiate into fibroblastic cells in culture in order to better understand the mechanisms that control this process and its relationship to the phenotypic changes that occur in chondrocytes during the development of @entity571 ( @entity571 ). METHODS: @entity1 fetal epiphyseal chondrocytes (HFCs) were cultured either on @entity27023 -coated plates (differentiated HFC cultures) or in plastic tissue culture flasks as monolayers (dedifferentiated HFC cultures). Following 11 days of culture under either condition, @entity12564 RNA was isolated from the two cell populations and subjected to a gene expression analysis using a microarray containing approximately 5,000 known @entity1 genes and approximately 3,000 expressed sequence tags (ESTs). RESULTS: A > or =2-fold difference in the expression of 62 known genes and 6 ESTs was observed between the two cell types. The differences in expression of several of the genes detected by the microarray hybridization were confirmed by Northern analyses. Two transcription factor genes, @entity8945 and @entity7738 , and a cellular adhesion protein gene, @entity31492 , were markedly regulated in response to differentiation and dedifferentiation. Expression of these genes was also detected in adult normal and @entity571 cartilage and chondrocytes. Analysis of the gene expression profile of HFCs revealed a complex pattern of gene expression, including many genes not yet reported to be expressed by chondrocytes. CONCLUSION: Chondrocytes in monolayer become dedifferentiated, acquiring a fibroblast-like appearance and changing their pattern of gene expression from one of expression of chondrocyte-specific genes to one that resembles a fibroblastic or chondroprogenitor-like pattern. Changes in gene expression associated with the process of dedifferentiation of HFCs in vitro were observed in a wide variety of genes, including genes encoding extracellular matrix proteins, transcription factors, and growth factors. At least 3 of the genes that were regulated in response to dedifferentiation were also found to be expressed in adult normal and @entity1844 and chondrocytes.

Assessment of the gene expression profile of differentiated and dedifferentiated XXXX fetal chondrocytes by microarray analysis.

@entity1 :: ('9606', 'Species') :: ['human', 'Human'] @entity7738 :: ('3091', 'Gene') :: ['HIF-1alpha'] @entity1844 :: ('MESH:D002357', 'Disease') :: ['OA articular cartilage'] @entity571 :: ('MESH:D010003', 'Disease') :: ['osteoarthritis', 'OA'] @entity27023 :: ('CHEBI:60758', 'Chemical') :: ['poly-(2-hydroxyethyl methacrylate)'] @entity31492 :: ('1009', 'Gene') :: ['cadherin 11'] @entity8945 :: ('7291', 'Gene') :: ['TWIST'] @entity12564 :: ('MESH:D011061', 'Chemical') :: ['poly(A+)']
@entity1 :: (9606,Species) :: ['human']
