Project description:Identifying PDEF regulated genes may shed light on the mechanism by which PDEF may induce breast cancer progression. To that purpose, we have used the MCF-7 human breast tumor cell line model to identify PDEF induced genes. Briefly, PDEF expression was down regulated by shRNA in MCF-7 cells and RNA probes from PDEF-down regulated and control MCF-7 cells were used to screen the Affymetrics HG-U133A Gene Chips. This analysis found 62 genes that were induced 2-fold or higher by PDEF. Further analysis of 3 of these genes namely S100A7, CEACAM6 and B7-H4 in primary breast tumors showed CEACAM6 as a frequently elevated and co-exressed gene with PDEF in these tumors. We previously reported a role for PDEF (prostate derived Ets transcription factor) in breast tumor progression and its association with poor clinical outcome in ER+ breast cancer. To gain further insights into PDEF action in breast cancer, we down regulated PDEF expression by shRNA in MCF-7 human breast tumor cell line, and screened the HG-U133A human gene chips with probes from PDEF down-regulated and control MCF-7 cells. This analysis identified CEACAM6 as one of the genes induced by PDEF. Further analysis of CEACAM6 expression in relation to PDEF in 93 ER+ primary breast tumors showed largely concordant expression of these molecules. To our knowledge, our findings of CEACAM6 as a PDEF induced gene and their elevated co-expression in breast cancer have not been described before.
Project description:Identifying PDEF regulated genes may shed light on the mechanism by which PDEF may induce breast cancer progression. To that purpose, we have used the MCF-7 human breast tumor cell line model to identify PDEF induced genes. Briefly, PDEF expression was down regulated by shRNA in MCF-7 cells and RNA probes from PDEF-down regulated and control MCF-7 cells were used to screen the Affymetrics HG-U133A Gene Chips. This analysis found 62 genes that were induced 2-fold or higher by PDEF. Further analysis of 3 of these genes namely S100A7, CEACAM6 and B7-H4 in primary breast tumors showed CEACAM6 as a frequently elevated and co-exressed gene with PDEF in these tumors. We previously reported a role for PDEF (prostate derived Ets transcription factor) in breast tumor progression and its association with poor clinical outcome in ER+ breast cancer. To gain further insights into PDEF action in breast cancer, we down regulated PDEF expression by shRNA in MCF-7 human breast tumor cell line, and screened the HG-U133A human gene chips with probes from PDEF down-regulated and control MCF-7 cells. This analysis identified CEACAM6 as one of the genes induced by PDEF. Further analysis of CEACAM6 expression in relation to PDEF in 93 ER+ primary breast tumors showed largely concordant expression of these molecules. To our knowledge, our findings of CEACAM6 as a PDEF induced gene and their elevated co-expression in breast cancer have not been described before. Data from one replicate experiment is included as a representative example of the data obtained. HG-U133A gene chip pairs were screeened with biotinylated RNA probes from PDEF-down regulated MCF-7 cells (experimental) or from control MCF-7 cells.
Project description:MDA-MB-231 breast cancer cells were infected with either Ad-GFP, Ad-FLI1, or Ad-PDEF qPCR gene expression profiling of MDA-MB-231 breast cancer cells were infected with either Ad-GFP, Ad-FLI1, or Ad-PDEF.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
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:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.
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:CEACAM family proteins have been extensively studied as cell adhesion molecules, yet the biological and clinical significance of CEACAM6 remains relatively unexplored. Our research identifies a significant increase in CEACAM6 expression in lung adenocarcinoma, particularly correlating with EGFR mutation status. In EGFR-mutated lung cancer cells, CEACAM6 knockdown induced apoptosis and reduced p-ERK1/2 signaling downstream of EGFR. Treatment with EGFR-tyrosine kinase inhibitors (TKIs) decreased CEACAM6 levels, leading to TKI-resistant lung cancer cells that exhibited reduced p-ERK1/2 and increased epithelial-mesenchymal transition (EMT) characteristics. Co-immunoprecipitation assays revealed an interaction between CEACAM6 and EGFR. Although CEACAM6 expression was lost in EGFR-TKI resistant cells, its re-expression stabilized EGFR and increased sensitivity to EGFR-TKIs. TGF-? treatment, which induced EMT, also decreased CEACAM6 expression and improved EGFR-TKI resistance. Further analysis showed that EGFR-TKI resistant lung cancer cells had lower H3K27ac epigenetic modification levels at the CEACAM6 locus than EGFR-TKI sensitive cells. Treatment with HDAC1/2 inhibitors in EGFR-TKI sensitive cells reduced CEACAM6 expression, induced EMT and TGF-?-ligand/receptor gene expression, and enhanced EGFR-TKI resistance. These data highlight the crucial role of CEACAM6 in maintaining oncogenic EGFR signaling and its regulation by cytokine stimulation and epigenetic modification, influencing EGFR-TKI sensitivity. Our findings underscore CEACAM6's potential as a valuable biomarker in EGFR-driven lung adenocarcinoma and its intricate involvement in EGFR-related pathways.