Project description:Follistatin is a folliculogenesis regulating protein that has been found in relatively high concentration in the female ovarian tissues. Follistatin acts as an antagonist to the function of Activin, which is often found elevated in ovarian carcinogenesis and thus presents a possibility for therapeutic intervention in controlling ovarian cancer. Most of the ovarian cancer occurs in its ovarian surface epithelium (OSE) cells. Although breast cancer susceptibility gene 1 (BRCA1) is a known tumor suppressor for breast cancer but its role in ovarian cancer is beginning to unfold. We have shown that in ovarian carcinoma cells (SKOV3), stable overexpression of BRCA1 stimulates Follistatin secretion and simultaneously downregulates Activin expression. Moreover, knock down of BRCA1 in immortalized OSE (IOSE) cells from human ovarian tissue demonstrates downregulation of Follistatin secretion with simultaneous up regulation of Activin expression. IOSE cells generated from an ovarian cancer patient with BRCA1 mutation failed to secrete Follistatin in the medium. Our results indicate a novel function for BRCA1 in the form of regulation of the expression of Follistatin in the ovarian cells. 3 treatments vs 3 controls
Project description:Follistatin is a folliculogenesis regulating protein that has been found in relatively high concentration in the female ovarian tissues. Follistatin acts as an antagonist to the function of Activin, which is often found elevated in ovarian carcinogenesis and thus presents a possibility for therapeutic intervention in controlling ovarian cancer. Most of the ovarian cancer occurs in its ovarian surface epithelium (OSE) cells. Although breast cancer susceptibility gene 1 (BRCA1) is a known tumor suppressor for breast cancer but its role in ovarian cancer is beginning to unfold. We have shown that in ovarian carcinoma cells (SKOV3), stable overexpression of BRCA1 stimulates Follistatin secretion and simultaneously downregulates Activin expression. Moreover, knock down of BRCA1 in immortalized OSE (IOSE) cells from human ovarian tissue demonstrates downregulation of Follistatin secretion with simultaneous up regulation of Activin expression. IOSE cells generated from an ovarian cancer patient with BRCA1 mutation failed to secrete Follistatin in the medium. Our results indicate a novel function for BRCA1 in the form of regulation of the expression of Follistatin in the ovarian cells.
Project description:We generate induced pluripotent stem cells (iPSCs) from healthy individuals and young ovarian cancer patients with germline pathogenic BRCA1 mutations. We then differentiate them into a human iPSC-derived fallopian tube organoid model. We recapitulated BRCA1 mutant ovarian carcinogenesis in vitro and showed tumors in vivo. Using the IPSC derived fallopian tube organoid model, we identify a unique transcriptional profile associated with BRCA1 mutation similar to the ovarian cancer profile.
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.
Project description:Cortical thickness has been investigated since the beginning of the 20th century, but we do not know how similar the cortical thickness profiles among humans are. In this study, the local similarity of cortical thickness profiles was investigated using sliding window methods. Here, we show that approximately 5% of the cortical thickness profiles are similarly expressed among humans while 45% of the cortical thickness profiles show a high level of heterogeneity. Therefore, heterogeneity is the rule, not the exception. Cortical thickness profiles of somatosensory homunculi and the anterior insula are consistent among humans, while the cortical thickness profiles of the motor homunculus are more variable. Cortical thickness profiles of homunculi that code for muscle position and skin stimulation are highly similar among humans despite large differences in sex, education, and age. This finding suggests that the structure of these cortices remains well preserved over a lifetime. Our observations possibly relativize opinions on cortical plasticity.
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:Mutations in BRCA1 and BRCA2 genes confer an increased lifetime risk for breast and ovarian cancer. Ovarian cancer risk can be decreased by risk-reducing salpingo-oophorectomy (RRSO). Studies on RRSO material have altered the paradigm of serous ovarian cancer pathogenesis. The purpose of this study was to identify candidate genes possibly involved in pathogenesis of serous ovarian cancer by carrying out a microarray analysis of differentially expressed genes in BRCA1/2- mutation positive ovarian and fallopian tube epithelium derived from RRSO surgery. Freshly frozen ovarian and fallopian tube samples from nine BRCA1/2 mutation carriers scheduled for RRSO were prospectively collected in comparison with five mutation-negative control patients undergoing salpingo-oophorectomy for benign indications. Microarray analysis of genome-wide gene expression was performed on ovarian and fallopian tube samples from BRCA1/2 and control patients. The validation of microarray data was performed by quantitative real-time polymerase chain reaction (qRT-PCR) in selected cases of RRSO samples, and also high grade serous carcinoma samples collected from patients with BRCA phenotype. From 22,733 genes, 454 transcripts were identified that were differentially expressed in BRCA1/2 mutation carriers when statistically compared to controls pooling all ovarian and fallopian tube samples together. Of these, 299 genes were statistically significantly downregulated and 155 genes were upregulated. Differentially expressed genes in BRCA1/2 samples reported here might be involved in serous ovarian carcinogenesis and provide interesting targets for further studies. Both fallopian tube and ovarian samples were collected from each BRCA1/2 mutation carrier resulting in eighteen mutation positive adnexal samples. Both fallopian tube and ovarian control samples were collected from one control patient while either ovarian or fallopian tube sample was available from four control patients, respectively, resulting in 6 adnexal control samples. High quality RNA was available from nine BRCA1/2-mutation positive ovarian and eight BRCA1/2-mutation positive fallopian tube samples and from three control ovarian and three control fallopian tube samples.