Project description:Normal and two transformed buccal keratinocyte lines were cultured under a standardized condition to explore mechanisms of carcinogenesis and tumor marker expression at transcript and protein level. An approach combining three bioinformatic programs allowed coupling of abundant proteins and large-scale transcript data to low-abundance transcriptional regulators. The analysis identified previously proposed, and suggested novel, protein biomarkers, Gene Ontology categories and molecular networks including functionally impaired key regulator genes for buccal/oral carcinoma. Experiment Overall Design: Analysis of differential expression in two transformed buccal keratinocyte lines (SVpgC2a and SqCC/Y1) relative to normal buccal keratinocytes. Both normal and transformed cells were cultured under a standardized serum-free condition. Experiment Overall Design: Two replicates for all cell types were included.
Project description:Serum-driven responses, many of which are related to wound healing, are potentially deregulated in cancer development and associated genomic alterations might have prognostic value. The current study assessed fetal bovine serum-induced transcriptomic changes for clinical relevance in head and neck squamous cell carcinoma (HNSCC) using oral keratinocyte models otherwise routinely cultured without serum, including normal keratinocytes (NOK) and the transformed keratinocyte lines SVpgC2a, SqCC/Y1 and LK0412. Bioinformatics-driven analysis of gene expression implicated primarily serum-induced terminal differentiation in NOK including alterations in 99 genes, 13 gene ontology-categories and 6 molecular networks and involvement of 7 key regulator genes. Compared to NOK, the transformed lines expressed around 3-fold lower numbers of differently expressed transcripts, unique sets of gene ontologies, molecular networks and key regulator genes for each line, and consistent absence of terminal differentiation markers. Assessment of the complete in vitro/serum exposure-derived set of differentially expressed genes (totally 180 genes) relative a clinical, information-rich HNSCC data set identified 17 survival-associated genes of which only 12 had previous association to HNSCC. Multi-step validation of the survival-associated genes relative to several independent tumor data sets, including in the Human Gene Expression Map and Human Protein Atlas databases, confirmed novel association to HNSCC for genes COTL1 and INSIG1 and novel poor outcome prediction for the genes CUL4B and PDGFRL. The definition of normal and aberrant serum responses in keratinocyte models therefore coupled new genes to HNSCC including with relevance to prognosis. Analysis of gene expression changes in serum-exposed normal and transformed cells relative the respective un-exposed states. Significantly differentially expressed genes were next assessed by bioinformatics processing using Gene Ontology categories and network analyses. Findings were also validated relative independent HNSCC data sets as well as transcriptomics and proteomics databases.
Project description:Serum-driven responses, many of which are related to wound healing, are potentially deregulated in cancer development and associated genomic alterations might have prognostic value. The current study assessed fetal bovine serum-induced transcriptomic changes for clinical relevance in head and neck squamous cell carcinoma (HNSCC) using oral keratinocyte models otherwise routinely cultured without serum, including normal keratinocytes (NOK) and the transformed keratinocyte lines SVpgC2a, SqCC/Y1 and LK0412. Bioinformatics-driven analysis of gene expression implicated primarily serum-induced terminal differentiation in NOK including alterations in 99 genes, 13 gene ontology-categories and 6 molecular networks and involvement of 7 key regulator genes. Compared to NOK, the transformed lines expressed around 3-fold lower numbers of differently expressed transcripts, unique sets of gene ontologies, molecular networks and key regulator genes for each line, and consistent absence of terminal differentiation markers. Assessment of the complete in vitro/serum exposure-derived set of differentially expressed genes (totally 180 genes) relative a clinical, information-rich HNSCC data set identified 17 survival-associated genes of which only 12 had previous association to HNSCC. Multi-step validation of the survival-associated genes relative to several independent tumor data sets, including in the Human Gene Expression Map and Human Protein Atlas databases, confirmed novel association to HNSCC for genes COTL1 and INSIG1 and novel poor outcome prediction for the genes CUL4B and PDGFRL. The definition of normal and aberrant serum responses in keratinocyte models therefore coupled new genes to HNSCC including with relevance to prognosis.
Project description:Gene expression profilings of normal human oral keratinocyte (HOK) and dysplastic oral keratinocyte cell line from a heavy smoker (DOK)
Project description:Normal and two transformed buccal keratinocyte lines were cultured under a standardized condition to explore mechanisms of carcinogenesis and tumor marker expression at transcript and protein level. An approach combining three bioinformatic programs allowed coupling of abundant proteins and large-scale transcript data to low-abundance transcriptional regulators. The analysis identified previously proposed, and suggested novel, protein biomarkers, Gene Ontology categories and molecular networks including functionally impaired key regulator genes for buccal/oral carcinoma. Keywords: Cell type comparison
Project description:Common overexpressing genes were identified in all human oral squamous cell carcinoma tissues and/or cultured cells. Ten oral squamous cell carcinoma tissues and 10 human oral squamous cell carcinoma cell lines were analyzed. Three normal oral mucosa tissues and a human non-neoplastic keratinocyte cell lines were used as control samples.
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.
Project description:As the evolution of miRNA genes has been found to be one of the important factors in formation of the modern type of man, we performed a comparative analysis of the evolution of miRNA genes in two archaic hominines, Homo sapiens neanderthalensis and Homo sapiens denisova, and elucidated the expression of their target mRNAs in bain.A comparative analysis of the genomes of primates, including species in the genus Homo, identified a group of miRNA genes having fixed substitutions with important implications for the evolution of Homo sapiens neanderthalensis and Homo sapiens denisova. The mRNAs targeted by miRNAs with mutations specific for Homo sapiens denisova exhibited enhanced expression during postnatal brain development in modern humans. By contrast, the expression of mRNAs targeted by miRNAs bearing variations specific for Homo sapiens neanderthalensis was shown to be enhanced in prenatal brain development.Our results highlight the importance of changes in miRNA gene sequences in the course of Homo sapiens denisova and Homo sapiens neanderthalensis evolution. The genetic alterations of miRNAs regulating the spatiotemporal expression of multiple genes in the prenatal and postnatal brain may contribute to the progressive evolution of brain function, which is consistent with the observations of fine technical and typological properties of tools and decorative items reported from archaeological Denisovan sites. The data also suggest that differential spatial-temporal regulation of gene products promoted by the subspecies-specific mutations in the miRNA genes might have occurred in the brains of Homo sapiens denisova and Homo sapiens neanderthalensis, potentially contributing to the cultural differences between these two archaic hominines.
Project description:PurposeWe investigated the evidence of recent positive selection in the human phototransduction system at single nucleotide polymorphism (SNP) and gene level.MethodsSNP genotyping data from the International HapMap Project for European, Eastern Asian, and African populations was used to discover differences in haplotype length and allele frequency between these populations. Numeric selection metrics were computed for each SNP and aggregated into gene-level metrics to measure evidence of recent positive selection. The level of recent positive selection in phototransduction genes was evaluated and compared to a set of genes shown previously to be under recent selection, and a set of highly conserved genes as positive and negative controls, respectively.ResultsSix of 20 phototransduction genes evaluated had gene-level selection metrics above the 90th percentile: RGS9, GNB1, RHO, PDE6G, GNAT1, and SLC24A1. The selection signal across these genes was found to be of similar magnitude to the positive control genes and much greater than the negative control genes.ConclusionsThere is evidence for selective pressure in the genes involved in retinal phototransduction, and traces of this selective pressure can be demonstrated using SNP-level and gene-level metrics of allelic variation. We hypothesize that the selective pressure on these genes was related to their role in low light vision and retinal adaptation to ambient light changes. Uncovering the underlying genetics of evolutionary adaptations in phototransduction not only allows greater understanding of vision and visual diseases, but also the development of patient-specific diagnostic and intervention strategies.