Project description:We used laser-capture microdissection (LCM) to separate tumor epithelium (TE) from stroma (TS) in 23 ILC samples. Gene expression analysis was used to identify genes that are enriched in the stroma of ILC, but not IDC or normal breast.
Project description:To better understand the role of tumor microenvironment in breast cancer progression, we combined laser capture microdissection and microarray analysis to provide a comprehensive catalog of gene expression changes in both tumor and tumor-associated stroma. Experiment Overall Design: We used LCM to isolate the epithelial and stroma compartments separately from each of 14 fresh frozen primary breast cancer biopsies. In the epithelial compartment, we captured normal (N) and malignant (DCIS or IDC or both where available) epithelium from each tissue slide. In the stroma compartment, we captured both normal stroma away from the malignant lesion (NSS) and the DCIS-associated stroma (ISS) and/or IDC-associated stroma (INVS) whenever possible.
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:Gene expression profiles of tumor epithelium and tumor-associated stroma of HER2+ breast tumors, plus normal epithelium and stroma from HER2+ and HER2- breast tumors
Project description:Tumor epithelium and surrounding stromal cells were isolated using laser capture microdissection of human breast cancer to examine differences in gene expression based on tissue types from inflammatory and non-inflammatory breast cancer Experiment Overall Design: We applied LCM to obtain samples enriched in tumor epithelium and stroma from 15 IBC and 35 non-IBC cases to study the relative contribution of each component to the IBC phenotype and to patient survival.
Project description:Malignant epithelia and tumor-associated stroma of PABC and Non-PABC were isolated by laser capture microdissection and gene expression profiled. Additionally, normal breast epithelia and stroma adjacent to the two tumor types were profiled. Lastly, subsets of previously identified E- and P-regulated genes were defined in all tissues. Breast cancers have been obtained from women whose tumors arose while they were pregnant or within 1 year of delivery and from age-matched controls who had never been pregnant. Malignant epithelial cells were separated by laser capture microdissection (LCM) of frozen sections. RNA was isolated and analyzed by expression profiling using Affymetrix U133 2plus Human Gene Chips
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.