ABSTRACT
Large-scale single-pass sequencing of randomly selected cDNA clones from cell type specific libraries has proven to be a powerful approach for the discovery of novel gene functions, identification of novel gene family members, and definition of gene expression profiles. HCS-2/8 chondrocyte has been used as a cell culture model to study chondrocyte differentiation. Here we performed 3350 single-pass sequencing reactions obtained from the 5' ends of cDNAs from HCS-2/8 cells. To define the expression profiles of HCS-2/8 chondrocytes, we analyzed the identity of these representative cDNA sequences using database searches (BLAST). The sequences represent 1927 unique genes with known function (i.e., unigene clusters), 38 transcripts that are similar to genes with known function, 739 expressed genes with unknown function (i.e., expressed sequence tags), and 18 cDNAs which have not previously been sequenced. Interestingly, many transcripts were expressed from chromosome 12 compared with total genes, while the fewer numbers of cDNAs were derived from genes on chromosomes 14, 18 and Y. The chondrocytic phenotype of HCS-2/8 cells is reflected by abundant expression of genes related to cell structure and motility and the 20 most frequently expressed unigenes reflect a chondrocyte-related gene expression signature. Thus, our data establish a representative set of more than 2000 genes expressed in a chondrocytic cell line. This finding provides a framework for understanding cell growth and differentiation of chondrocytes and their metabolic function in the formation and remodeling of cartilage.
Subject(s)
Expressed Sequence Tags , Gene Expression Profiling , Cell Line, Tumor , Chondrosarcoma/genetics , Chondrosarcoma/pathology , DNA, Complementary/chemistry , DNA, Complementary/genetics , Gene Expression Regulation, Neoplastic , Gene Library , Humans , Sequence Analysis, DNAABSTRACT
The biological activity of osteoblasts on the newly developed bioactive poly(methyl methacrylate) (PMMA)/silica hybrid containing calcium salt was investigated. The attachment, proliferation, and differentiation of primary cultured mouse calvarial osteoblasts were evaluated by hexosaminase, MTT, and alkaline phosphatase activity assays, respectively. The PMMA/silica hybrid showed higher biological activities than those of pure PMMA with regard to all three parameters. Besides, the calcium phosphate layer, determined by scanning electron microscopy with energy dispersive spectroscopy, occurred only on the PMMA/silica hybrid. Better biological activities on the PMMA/silica hybrid than those on the PMMA were explained by the role of calcium phosphate layer formed on the PMMA/silica hybrid and the released calcium and silicon ions from it during the cell culture. These results suggest that the PMMA/silica hybrid might be useful as a bone substitute or filler.
