Publications by authors named "Lisa D White"

23 Publications

  • Page 1 of 1

Survey on Scientific Shared Resource Rigor and Reproducibility.

J Biomol Tech 2019 09;30(3):36-44

University of Virginia School of Medicine, Charlottesville, Virginia 22908, USA.

Shared scientific resources, also known as core facilities, support a significant portion of the research conducted at biomolecular research institutions. The Association of Biomolecular Resource Facilities (ABRF) established the Committee on Core Rigor and Reproducibility (CCoRRe) to further its mission of integrating advanced technologies, education, and communication in the operations of shared scientific resources in support of reproducible research. In order to first assess the needs of the scientific shared resource community, the CCoRRe solicited feedback from ABRF members a survey. The purpose of the survey was to gain information on how U.S. National Institutes of Health (NIH) initiatives on advancing scientific rigor and reproducibility influenced current services and new technology development. In addition, the survey aimed to identify the challenges and opportunities related to implementation of new reporting requirements and to identify new practices and resources needed to ensure rigorous research. The results revealed a surprising unfamiliarity with the NIH guidelines. Many of the perceived challenges to the effective implementation of best practices (, those designed to ensure rigor and reproducibility) were similarly noted as a challenge to effective provision of support services in a core setting. Further, most cores routinely use best practices and offer services that support rigor and reproducibility. These services include access to well-maintained instrumentation and training on experimental design and data analysis as well as data management. Feedback from this survey will enable the ABRF to build better educational resources and share critical best-practice guidelines. These resources will become important tools to the core community and the researchers they serve to impact rigor and transparency across the range of science and technology.
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http://dx.doi.org/10.7171/jbt.19-3003-001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6657953PMC
September 2019

Publisher Correction: EMT cells increase breast cancer metastasis via paracrine GLI activation in neighbouring tumour cells.

Nat Commun 2018 11 12;9(1):4720. Epub 2018 Nov 12.

Department of Pharmacology, University of Colorado-Denver, 12800 East 19th Avenue, Room P18-6115, Aurora, Colorado, 80045, USA.

This Article contains an error in Figure 2. In panel a, the second lane of the western blot should have been labelled 'siNT'. A correct version of Figure 2a appears in the Author Correction associated with this Article; the error has not been fixed in the original Article.
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http://dx.doi.org/10.1038/s41467-018-07168-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6232083PMC
November 2018

Retinoid signaling controlled by SRC-2 in decidualization revealed by transcriptomics

Reproduction 2018 10 16;156(5):387-395. Epub 2018 Oct 16.

Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, Texas, USA.

Establishment of a successful pregnancy requires not only implantation of a healthy embryo into a receptive uterus but also progesterone receptor (PGR)-dependent transformation of endometrial stromal cells (ESCs) into specialized decidual cells. Decidual cells support the developing embryo and are critical for placentation. We have previously shown that a known transcriptional coregulator of the PGR, steroid receptor coactivator-2 (SRC-2), is a critical driver of endometrial decidualization in both human and mouse endometrium. However, the full spectrum of genes transcriptionally controlled by SRC-2 in decidualizing ESCs has not been identified. Therefore, using an RNA- and chromatin immunoprecipitation-sequencing approach, we have identified the transcriptome of decidualizing human ESCs (hESCs) that requires SRC-2. We revealed that the majority of hESC genes regulated by SRC-2 are associated with decidualization. Over 50% of SRC-2-regulated genes are also controlled by the PGR. While ontology analysis showed that SRC-2-dependent genes are functionally linked to signaling processes known to underpin hESC decidualization, cell membrane processes were significantly enriched in this analysis. Follow-up studies showed that retinoid signaling is dependent on SRC-2 during hESC decidualization. Specifically, SRC-2 is required for full induction of the retinol transporter, stimulated by retinoic acid 6 (STRA6), which is essential for hESC decidualization. Together our findings show that a critical subset of genes transcriptionally reprogramed by PGR during hESC decidualization requires SRC-2. Among the multiple genes, pathways and networks that are dependent on SRC-2 during hESC decidualization, first-line analysis supports a critical role for this coregulator in maintaining retinoid signaling during progesterone-driven decidualization.
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http://dx.doi.org/10.1530/REP-18-0282DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6208442PMC
October 2018

Human endometrial stromal cell decidualization requires transcriptional reprogramming by PLZF.

Biol Reprod 2018 01;98(1):15-27

Department of Molecular & Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, Texas, USA.

Infertility and early embryo miscarriage is linked to inadequate endometrial decidualization. Although transcriptional reprogramming is known to drive decidualization in response to progesterone, the key signaling effectors that directly mediate this hormone response are not fully known. This knowledge gap is clinically significant because identifying the early signals that directly mediate progesterone-driven decidualization will address some of the current limitations in diagnosing and therapeutically treating patients at most risk for early pregnancy loss. We recently revealed that the promyelocytic leukemia zinc finger (PLZF) is a direct target of the progesterone receptor and is essential for decidualization of human endometrial stromal cells (hESCs). The purpose of this current work was to identify the genome-wide transcriptional program that is controlled by PLZF during hESC decidualization using an established in vitro hESC culture model, siRNA-mediated knockdown methods, and RNA-sequencing technology followed by bioinformatic analysis and validation. We discovered that PLZF is critical in the regulation of genes that are involved in cellular processes that are essential for the archetypal morphological and functional changes that occur when hESCs transform into epithelioid decidual cells such as proliferation and cell motility. We predict that the transcriptome datasets identified in this study will not only contribute to a broader understanding of PLZF-dependent endometrial decidualization at the molecular level but may advance the development of more effective molecular diagnostics and therapeutics for the clinical management of female infertility and subfertility that is based on a dysfunctional endometrium.
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http://dx.doi.org/10.1093/biolre/iox161DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5819842PMC
January 2018

EMT cells increase breast cancer metastasis via paracrine GLI activation in neighbouring tumour cells.

Nat Commun 2017 06 12;8:15773. Epub 2017 Jun 12.

Department of Pharmacology, University of Colorado-Denver, 12800 East 19th Avenue, Room P18-6115, Aurora, Colorado 80045, USA.

Recent fate-mapping studies concluded that EMT is not required for metastasis of carcinomas. Here we challenge this conclusion by showing that these studies failed to account for possible crosstalk between EMT and non-EMT cells that promotes dissemination of non-EMT cells. In breast cancer models, EMT cells induce increased metastasis of weakly metastatic, non-EMT tumour cells in a paracrine manner, in part by non-cell autonomous activation of the GLI transcription factor. Treatment with GANT61, a GLI1/2 inhibitor, but not with IPI 926, a Smoothened inhibitor, blocks this effect and inhibits growth in PDX models. In human breast tumours, the EMT-transcription factors strongly correlate with activated Hedgehog/GLI signalling but not with the Hh ligands. Our findings indicate that EMT contributes to metastasis via non-cell autonomous effects that activate the Hh pathway. Although all Hh inhibitors may act against tumours with canonical Hh/GLI signalling, only GLI inhibitors would act against non-canonical EMT-induced GLI activation.
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http://dx.doi.org/10.1038/ncomms15773DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5472791PMC
June 2017

Mig-6 plays a critical role in the regulation of cholesterol homeostasis and bile acid synthesis.

PLoS One 2012 17;7(8):e42915. Epub 2012 Aug 17.

Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, United States of America.

The disruption of cholesterol homeostasis leads to an increase in cholesterol levels which results in the development of cardiovascular disease. Mitogen Inducible Gene 6 (Mig-6) is an immediate early response gene that can be induced by various mitogens, stresses, and hormones. To identify the metabolic role of Mig-6 in the liver, we conditionally ablated Mig-6 in the liver using the Albumin-Cre mouse model (Alb(cre/+)Mig-6(f/f); Mig-6(d/d)). Mig-6(d/d) mice exhibit hepatomegaly and fatty liver. Serum levels of total, LDL, and HDL cholesterol and hepatic lipid were significantly increased in the Mig-6(d/d) mice. The daily excretion of fecal bile acids was significantly decreased in the Mig-6(d/d) mice. DNA microarray analysis of mRNA isolated from the livers of these mice showed alterations in genes that regulate lipid metabolism, bile acid, and cholesterol synthesis, while the expression of genes that regulate biliary excretion of bile acid and triglyceride synthesis showed no difference in the Mig-6(d/d) mice compared to Mig-6(f/f) controls. These results indicate that Mig-6 plays an important role in cholesterol homeostasis and bile acid synthesis. Mice with liver specific conditional ablation of Mig-6 develop hepatomegaly and increased intrahepatic lipid and provide a novel model system to investigate the genetic and molecular events involved in the regulation of cholesterol homeostasis and bile acid synthesis. Defining the molecular mechanisms by which Mig-6 regulates cholesterol homeostasis will provide new insights into the development of more effective ways for the treatment and prevention of cardiovascular disease.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0042915PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3422237PMC
May 2013

Genomic hypomethylation in the human germline associates with selective structural mutability in the human genome.

PLoS Genet 2012 17;8(5):e1002692. Epub 2012 May 17.

Bioinformatics Research Laboratory, Epigenome Center, Baylor College of Medicine, Houston, Texas, United States of America.

The hotspots of structural polymorphisms and structural mutability in the human genome remain to be explained mechanistically. We examine associations of structural mutability with germline DNA methylation and with non-allelic homologous recombination (NAHR) mediated by low-copy repeats (LCRs). Combined evidence from four human sperm methylome maps, human genome evolution, structural polymorphisms in the human population, and previous genomic and disease studies consistently points to a strong association of germline hypomethylation and genomic instability. Specifically, methylation deserts, the ~1% fraction of the human genome with the lowest methylation in the germline, show a tenfold enrichment for structural rearrangements that occurred in the human genome since the branching of chimpanzee and are highly enriched for fast-evolving loci that regulate tissue-specific gene expression. Analysis of copy number variants (CNVs) from 400 human samples identified using a custom-designed array comparative genomic hybridization (aCGH) chip, combined with publicly available structural variation data, indicates that association of structural mutability with germline hypomethylation is comparable in magnitude to the association of structural mutability with LCR-mediated NAHR. Moreover, rare CNVs occurring in the genomes of individuals diagnosed with schizophrenia, bipolar disorder, and developmental delay and de novo CNVs occurring in those diagnosed with autism are significantly more concentrated within hypomethylated regions. These findings suggest a new connection between the epigenome, selective mutability, evolution, and human disease.
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http://dx.doi.org/10.1371/journal.pgen.1002692DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3355074PMC
September 2012

Constitutive activation of smoothened leads to female infertility and altered uterine differentiation in the mouse.

Biol Reprod 2010 May 3;82(5):991-9. Epub 2010 Feb 3.

Department of Molecular and Cellular Biology, Department of Molecular and Human Genetics, The Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, Texas 77030, USA.

Previous work has identified Indian hedgehog (Ihh) as a major mediator of progesterone signaling during embryo implantation. Ihh acts through its downstream effector smoothened (Smo) to activate the GLI family of transcription factors. In order to gain a better understanding of Ihh action during embryo implantation, we expressed a Cre-recombinase-dependent constitutively activated SMO in the murine uterus using the Pgr(tm2(cre)Lyd) (PR(cre)) mouse model [Pgr(tm2(cre)Lyd+)Gt(ROSA)26Sor(tm1(Smo/EYFP)Amc)(+) (PR(cre/+)SmoM2(+))]. Female PR(cre/+)SmoM2(+) mice were infertile. They exhibited normal serum progesterone levels and normal ovulation, but their ova failed to be fertilized in vivo and their uterus failed to undergo the artificially induced decidual response. Examination of the PR(cre/+)SmoM2(+) uteri revealed numerous features such as uterine hypertrophy, the presence of a stratified luminal epithelial cell layer, a reduced number of uterine glands, and an endometrial stroma that had lost its normal morphologic characteristics. Microarray analysis of 3-mo-old PR(cre/+)SmoM2(+) uteri demonstrated a chondrocytic signature and confirmed that constitutive activation of PR(cre/+)SmoM2(+) increased extracellular matrix production. Thus, constitutive activation of Smo in the mouse uterus alters postnatal uterine differentiation which interferes with early pregnancy. These results provide new insight into the role of Hedgehog signaling during embryo implantation.
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http://dx.doi.org/10.1095/biolreprod.109.081513DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2857637PMC
May 2010

Ablation of Indian hedgehog in the murine uterus results in decreased cell cycle progression, aberrant epidermal growth factor signaling, and increased estrogen signaling.

Biol Reprod 2010 Apr 7;82(4):783-90. Epub 2010 Jan 7.

Departments of Molecular and Cellular Biology and Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.

Conditional ablation of Indian hedgehog (Ihh) in the murine uterus results in mice that are sterile because of defects in embryo implantation. We performed microarray analysis on these mice at the time point at which the Ihh target genes are induced by the administration of exogenous hormone to mimic Day 3.5 of pregnancy. This analysis identified 863 genes altered by the conditional ablation of Ihh. Of these, genes that regulated the cell cycle were overrepresented. In addition, genes involved in epidermal growth factor (EGF) and estrogen (E2) signaling were found to be deregulated upon Ihh ablation. Furthermore, upon conditional ablation of Ihh, 15-mo-old mice exhibited hallmarks of estrogenized uteri, such as cystically dilated glands and hyalinized stroma. Thus, Ihh regulates embryo implantation by having an impact on the cell cycle, EGF signaling, and E2 signaling.
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http://dx.doi.org/10.1095/biolreprod.109.080259DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2842491PMC
April 2010

Regional genomic instability predisposes to complex dystrophin gene rearrangements.

Hum Genet 2009 Sep 16;126(3):411-23. Epub 2009 May 16.

Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, NAB 2015, Houston, TX 77030, USA.

Mutations in the dystrophin gene (DMD) cause Duchenne and Becker muscular dystrophies and the majority of cases are due to DMD gene rearrangements. Despite the high incidence of these aberrations, little is known about their causative molecular mechanism(s). We examined 792 DMD/BMD clinical samples by oligonucleotide array-CGH and report on the junction sequence analysis of 15 unique deletion cases and three complex intragenic rearrangements to elucidate potential underlying mechanism(s). Furthermore, we present three cases with intergenic rearrangements involving DMD and neighboring loci. The cases with intragenic rearrangements include an inversion with flanking deleted sequences; a duplicated segment inserted in direct orientation into a deleted region; and a splicing mutation adjacent to a deletion. Bioinformatic analysis demonstrated that 7 of 12 breakpoints combined among 3 complex cases aligned with repetitive sequences, as compared to 4 of 30 breakpoints for the 15 deletion cases. Moreover, the inversion/deletion case may involve a stem-loop structure that has contributed to the initiation of this rearrangement. For the duplication/deletion and splicing mutation/deletion cases, the presence of the first mutation, either a duplication or point mutation, may have elicited the deletion events in an attempt to correct preexisting mutations. While NHEJ is one potential mechanism for these complex rearrangements, the highly complex junction sequence of the inversion/deletion case suggests the involvement of a replication-based mechanism. Our results support the notion that regional genomic instability, aided by the presence of repetitive elements, a stem-loop structure, and possibly preexisting mutations, may elicit complex rearrangements of the DMD gene.
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http://dx.doi.org/10.1007/s00439-009-0679-9DOI Listing
September 2009

Mig-6 modulates uterine steroid hormone responsiveness and exhibits altered expression in endometrial disease.

Proc Natl Acad Sci U S A 2009 May 13;106(21):8677-82. Epub 2009 May 13.

Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA.

Normal endometrial function requires a balance of progesterone (P4) and estrogen (E2) effects. An imbalance caused by increased E2 action and/or decreased P4 action can result in abnormal endometrial proliferation and, ultimately, endometrial adenocarcinoma, the fourth most common cancer in women. We have identified mitogen-inducible gene 6 (Mig-6) as a downstream target of progesterone receptor (PR) and steroid receptor coactivator (SRC-1) action in the uterus. Here, we demonstrate that absence of Mig-6 in mice results in the inability of P4 to inhibit E2-induced uterine weight gain and E2-responsive target genes expression. At 5 months of age, the absence of Mig-6 results in endometrial hyperplasia. Ovariectomized Mig-6(d/d) mice exhibit this hyperplastic phenotype in the presence of E2 and P4 but not without ovarian hormone. Ovariectomized Mig-6(d/d) mice treated with E2 developed invasive endometrioid-type endometrial adenocarcinoma. Importantly, the observation that endometrial carcinomas from women have a significant reduction in MIG-6 expression provides compelling support for an important growth regulatory role for Mig-6 in the uterus of both humans and mice. This demonstrates the Mig-6 is a critical regulator of the response of the endometrium to E2 in regulating tissue homeostasis. Since Mig-6 is regulated by both PR and SRC-1, this identifies a PR, SRC-1, Mig-6 regulatory pathway that is critical in the suppression of endometrial cancer.
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http://dx.doi.org/10.1073/pnas.0903632106DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2681319PMC
May 2009

Clinical use of array comparative genomic hybridization (aCGH) for prenatal diagnosis in 300 cases.

Prenat Diagn 2009 Jan;29(1):29-39

Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, TX 77030, USA.

Objective: To evaluate the use of array comparative genomic hybridization (aCGH) for prenatal diagnosis, including assessment of variants of uncertain significance, and the ability to detect abnormalities not detected by karyotype, and vice versa.

Methods: Women undergoing amniocentesis or chorionic villus sampling (CVS) for karyotype were offered aCGH analysis using a targeted microarray. Parental samples were obtained concurrently to exclude maternal cell contamination and determine if copy number variants (CNVs) were de novo, or inherited prior to issuing a report.

Results: We analyzed 300 samples, most were amniotic fluid (82%) and CVS (17%). The most common indications were advanced maternal age (N=123) and abnormal ultrasound findings (N=84). We detected 58 CNVs (19.3%). Of these, 40 (13.3%) were interpreted as likely benign, 15 (5.0%) were of defined pathological significance, while 3 (1.0%) were of uncertain clinical significance. For seven (approximately 2.3% or 1/43), aCGH contributed important new information. For two of these (1% or approximately 1/150), the abnormality would not have been detected without aCGH analysis.

Conclusion: Although aCGH-detected benign inherited variants in 13.3% of cases, these did not present major counseling difficulties, and the procedure is an improved diagnostic tool for prenatal detection of chromosomal abnormalities.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3665952PMC
http://dx.doi.org/10.1002/pd.2127DOI Listing
January 2009

Rapid prenatal diagnosis using uncultured amniocytes and oligonucleotide array CGH.

Prenat Diagn 2008 Oct;28(10):943-9

Medical Genetics Laboratories, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.

Objective: Oligonucleotide-based array comparative genomic hybridization (array CGH) is an established method for detecting chromosomal abnormalities. Here, we explored the feasibility of using DNA extracted from uncultured amniocytes in amniotic fluid for array CGH on an oligonucleotide array platform.

Methods: Fifteen fetuses from 14 ongoing pregnancies were studied by array CGH on targeted oligonucleotide arrays with DNA isolated from direct amniotic fluid using a modified DNA extraction protocol.

Results: High-quality array CGH results were obtained for 13 samples with suboptimal but interpretable results in only 2 samples due to limited DNA amounts. Array CGH using whole genome amplification (WGA) of DNA for the two cases with limited DNA was successful, and results were consistent with those from unamplified DNA. For another five samples, the results of array CGH with amplified DNA matched those with unamplified DNA. Chromosome analysis was performed for 14 cases and was consistent with array CGH results.

Conclusion: This study demonstrates the feasibility of prenatal genetic diagnosis using oligonucleotide array CGH analysis for direct analysis of amniocytes without culturing cells. The use of oligonucleotide arrays increases the sensitivity and accuracy of detection over previous bacterial artificial chromosome (BAC)-based arrays. Furthermore, the direct analysis allows for rapid array CGH results and shorter reporting time.
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http://dx.doi.org/10.1002/pd.2087DOI Listing
October 2008

Bacterial artificial chromosome-emulation oligonucleotide arrays for targeted clinical array-comparative genomic hybridization analyses.

Genet Med 2008 Apr;10(4):278-89

Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA.

Purpose: The goal of this work was to test the ability of oligonucleotide-based arrays to reproduce the results of focused bacterial artificial chromosome (BAC)-based arrays used clinically in comparative genomic hybridization experiments to detect constitutional copy number changes in genomic DNA.

Methods: Custom oligonucleotide (oligo) arrays were designed using the Agilent Technologies platform to give high-resolution coverage of regions within the genome sequence coordinates of BAC/P1 artificial chromosome (PAC) clones that had already been validated for use in previous versions of clone arrays used in clinical practice. Standard array-comparative genomic hybridization experiments, including a simultaneous blind analysis of a set of clinical samples, were conducted on both array platforms to identify copy number differences between patient samples and normal reference controls.

Results: Initial experiments successfully demonstrated the capacity of oligo arrays to emulate BAC data without the need for dye-reversal comparisons. Empirical data and computational analyses of oligo response and distribution from a pilot array were used to design an optimized array of 44,000 oligos (44K). This custom 44K oligo array consists of probes localized to the genomic positions of >1400 fluorescence in situ hybridization-verified BAC/PAC clones covering more than 140 regions implicated in genetic diseases, as well as all clinically relevant subtelomeric and pericentromeric regions.

Conclusions: Our data demonstrate that oligo-based arrays offer a valid alternative for focused BAC arrays. Furthermore, they have significant advantages, including better design flexibility, avoidance of repetitive sequences, manufacturing processes amenable to good manufacturing practice standards in the future, increased robustness because of an enhanced dynamic range (signal to background), and increased resolution that allows for detection of smaller regions of change.
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http://dx.doi.org/10.1097/GIM.0b013e31816b4420DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2782565PMC
April 2008

Gene expression profiling in embryonic mouse lenses.

Mol Vis 2006 Dec 26;12:1692-8. Epub 2006 Dec 26.

College of Optometry, University of Houston, Houston, TX 77204-2020, USA.

Purpose: In this study, we used laser capture microdissection (LCM) and microarray hybridization technology to compare the gene expression profiles of mouse embryonic days 10 and 12 lenses (E10 and E12).

Methods: Lens cells of C57/BL6 mouse embryos at E10 and E12 were harvested using the PixCell II LCM System. Total RNA was extracted, amplified, labeled, and hybridized to the 430 2.0 mouse chip (Affymetrix) according to the manufacturer's instructions. Data extracted from the images were analyzed using different software programs. Regulated expression of selected genes was confirmed by real-time PCR (RT-PCR).

Results: Analysis of the microarray data from E10 and E12 lenses identified 1,573 genes that showed a two fold or greater change in expression level. Among these 1,573 genes, 956 genes were downregulated and 617 were upregulated in E12 lenses. In addition to the upregulated expression of beta- and gamma-crystallin genes, genes that regulate the cell cycle showed significant changes of gene expression during the E10 (lens pit) to E12 (primary fiber cell induction) time period. Genes involved in insulin-like growth factor (IGF) signaling and Wnt (a family of secreted glycoproteins related to the Drosophila segment polarity gene, wingless, and to the proto-oncogene, int-1) signaling were also differentially regulated. In particular, positive regulators of Wnt signaling were downregulated and negative regulators were upregulated, indicating that modulation of Wnt signaling is important for normal lens morphogenesis.

Conclusions: Our results provide new information about differential regulation of gene expression during early lens development. Analysis of global gene expression profiles in embryonic mouse lenses has allowed us to identify several molecular pathways that are differentially regulated during early lens development.
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December 2006

Reactivation of developmentally expressed p63 isoforms predisposes to tumor development and progression.

Cancer Res 2006 Apr;66(8):3981-6

Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA.

Genes that are active during normal development are frequently reactivated during neoplastic transformation. We now report that developmentally expressed TAp63 isoforms are frequently reactivated in human squamous cell carcinomas. To determine the consequences of TAp63 reactivation, we induced TAp63alpha expression during chemically-induced skin carcinogenesis. Deregulated TAp63alpha expression dramatically accelerated tumor development and progression, frequently resulting in epithelial-mesenchymal transitions to spindle cell carcinomas and lung metastases. Consistent with this observation, we detected high levels of Twist and N-cadherin in tumors overexpressing TAp63alpha. Thus, as observed for other developmental pathways, aberrant reactivation of TAp63 predisposes to tumor development and progression.
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http://dx.doi.org/10.1158/0008-5472.CAN-06-0027DOI Listing
April 2006

Dominant-stable beta-catenin expression causes cell fate alterations and Wnt signaling antagonist expression in a murine granulosa cell tumor model.

Cancer Res 2006 Feb;66(4):1964-73

Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA.

Wnt/beta-catenin signaling is normally involved in embryonic development and tissue homeostasis, and its misregulation leads to several forms of cancer. We have reported that misregulated Wnt/beta-catenin signaling occurs in ovarian granulosa cell tumors (GCT) and have created the Catnb(flox(ex3)/+);Amhr2(cre/+) mouse model, which expresses a dominant-stable mutant of beta-catenin in granulosa cells and develops late-onset GCT. To study the mechanisms leading to GCT development, gene expression analysis was done using microarrays comparing Catnb(flox(ex3)/+);Amhr2(cre/+) ovaries bearing pretumoral lesions with control ovaries. Overexpressed genes identified in Catnb(flox(ex3)/+);Amhr2(cre/+) ovaries included the Wnt/beta-catenin signaling antagonists Wif1, Nkd1, Dkk4, and Axin2, consistent with the induction of negative feedback loops that counteract uncontrolled Wnt/beta-catenin signaling. Expression of the antagonists was localized to cells forming the pretumoral lesions but not to normal granulosa cells. Microarray analyses also revealed the ectopic expression of bone markers, including Ibsp, Cdkn1c, Bmp4, and Tnfrsf11b, as well as neuronal/neurosecretory cell markers, such as Cck, Amph, Pitx1, and Sp5. Increased expression of the gene encoding the cytokine pleiotrophin was also found in Catnb(flox(ex3)/+);Amhr2(cre/+) ovaries and GCT but was not associated with increased serum pleiotrophin levels. In situ hybridization analyses using GCT from Catnb(flox(ex3)/+);Amhr2(cre/+) mice revealed that Wnt/beta-catenin antagonists and neuronal markers localized to a particular cell population, whereas the bone markers localized to a distinct cell type associated with areas of osseous metaplasia. Together, these results suggest that misregulated Wnt/beta-catenin signaling alters the fate of granulosa cells and that the GCT that arise in Catnb(flox(ex3)/+);Amhr2(cre/+) mice result from the clonal expansion of metaplastic cells.
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http://dx.doi.org/10.1158/0008-5472.CAN-05-3493DOI Listing
February 2006

The genomic analysis of the impact of steroid receptor coactivators ablation on hepatic metabolism.

Mol Endocrinol 2006 May 19;20(5):1138-52. Epub 2006 Jan 19.

Department of Molecular and Cellular Biology, Microarray Core Facility, Baylor College of Medicine, Houston, Texas 77030, USA.

Members of the steroid receptor coactivator (SRC) family, which include SRC-1 (NcoA-1/p160), SRC-2(TIF2/GRIP1/NcoA-2) and SRC-3(pCIP/RAC3/ACTR/pCIP/ AIB1/TRAM1), are critical mediators of steroid receptor action. Gene ablation studies previously identified SRC-1 and SRC-2 as being involved in the control of energy homeostasis. A more precise identification of the molecular pathways regulated by these coactivators is crucial for understanding the role of steroid receptor coactivators in the control of energy homeostasis and obesity. A genomic approach using microarray analysis was employed to identify the subsets of genes that are altered in the livers of SRC-1-/-, SRC-2-/-, and SRC-3-/- mice. Microarray analysis demonstrates that gene expression changes are specific and nonoverlapping for each SRC member in the liver. The overall pattern of altered gene expressions in the SRC-1-/- mice was up-regulation, whereas SRC-2-/- mice showed an overall down-regulation. Several key regulatory enzymes of energy metabolism were significantly altered in the liver of SRC-2-/- mice, which are consistent with the prior observation that SRC-2-/- mice have increased energy expenditure. This study demonstrates that the molecular targets of SRC-2 regulation in the murine liver stimulate fatty acid degradation and glycolytic pathway, whereas fatty acid, cholesterol, and steroid biosynthetic pathways are down-regulated.
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http://dx.doi.org/10.1210/me.2005-0407DOI Listing
May 2006

Spectrum of CHD7 mutations in 110 individuals with CHARGE syndrome and genotype-phenotype correlation.

Am J Hum Genet 2006 Feb 29;78(2):303-14. Epub 2005 Dec 29.

Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.

CHARGE syndrome is a well-established multiple-malformation syndrome with distinctive consensus diagnostic criteria. Characteristic associated anomalies include ocular coloboma, choanal atresia, cranial nerve defects, distinctive external and inner ear abnormalities, hearing loss, cardiovascular malformations, urogenital anomalies, and growth retardation. Recently, mutations of the chromodomain helicase DNA-binding protein gene CHD7 were reported to be a major cause of CHARGE syndrome. We sequenced the CHD7 gene in 110 individuals who had received the clinical diagnosis of CHARGE syndrome, and we detected mutations in 64 (58%). Mutations were distributed throughout the coding exons and conserved splice sites of CHD7. Of the 64 mutations, 47 (73%) predicted premature truncation of the protein. These included nonsense and frameshift mutations, which most likely lead to haploinsufficiency. Phenotypically, the mutation-positive group was more likely to exhibit cardiovascular malformations (54 of 59 in the mutation-positive group vs. 30 of 42 in the mutation-negative group; P=.014), coloboma of the eye (55 of 62 in the mutation-positive group vs. 30 of 43 in the mutation-negative group; P=.022), and facial asymmetry, often caused by seventh cranial nerve abnormalities (36 of 56 in the mutation-positive group vs. 13 of 39 in the mutation-negative group; P=.004). Mouse embryo whole-mount and section in situ hybridization showed the expression of Chd7 in the outflow tract of the heart, optic vesicle, facio-acoustic preganglion complex, brain, olfactory pit, and mandibular component of the first branchial arch. Microarray gene-expression analysis showed a signature pattern of gene-expression differences that distinguished the individuals with CHARGE syndrome with CHD7 mutation from the controls. We conclude that cardiovascular malformations, coloboma, and facial asymmetry are common findings in CHARGE syndrome caused by CHD7 mutation.
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http://dx.doi.org/10.1086/500273DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1380237PMC
February 2006

Identification of murine uterine genes regulated in a ligand-dependent manner by the progesterone receptor.

Endocrinology 2005 Aug 21;146(8):3490-505. Epub 2005 Apr 21.

Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA.

Progesterone (P4) acting through its cognate receptor, the progesterone receptor (PR), plays an important role in uterine physiology. The PR knockout (PRKO) mouse has demonstrated the importance of the P4-PR axis in the regulation of uterine function. To define the molecular pathways regulated by P4-PR in the mouse uterus, Affymetrix MG U74Av2 oligonucleotide arrays were used to identify alterations in gene expression after acute and chronic P4 treatments. PRKO and wild-type mice were ovariectomized and then treated with vehicle or 1 mg P4 every 12 h. Mice were killed either 4 h after the first injection (acute P4 treatment) or after the fourth injection of P4 (chronic P4 treatment). At the genomic level, the major change in gene expression after acute P4 treatment was an increase in the expression of 55 genes. Conversely, the major change in gene expression after chronic P4 treatment was an overall reduction in the expression of 102 genes. In the analysis, retinoic acid metabolic genes, cytochrome P 450 26a1 (Cyp26a1), alcohol dehydrogenase 5, and aldehyde dehydrogenase 1a1 (Aldh1a1); kallikrein genes, Klk5 and Klk6; and specific transcription factors, GATA-2 and Cited2 [cAMP-corticosterone-binding protein/p300-interacting transactivator with glutamic acid (E) and aspartic acid (D)-rich tail], were validated as regulated by the P4-PR axis. Identification and analysis of these responsive genes will help define the role of PR in regulating uterine biology.
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http://dx.doi.org/10.1210/en.2005-0016DOI Listing
August 2005

Development of a comparative genomic hybridization microarray and demonstration of its utility with 25 well-characterized 1p36 deletions.

Hum Mol Genet 2003 Sep 15;12(17):2145-52. Epub 2003 Jul 15.

Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.

Chromosomal abnormalities, such as deletions and duplications, are characterized by specific and often complex phenotypes resulting from an imbalance in normal gene dosage. However, routine chromosome banding is not sensitive enough to detect subtle chromosome aberrations (<5-10 Mb). Array-based comparative genomic hybridization (array CGH) is a powerful new technology capable of identifying chromosomal imbalance at a high resolution by co-hybridizing differentially labeled test and control DNAs to a microarray of genomic clones. We used a previously assembled contig of large-insert clones that span 10.5 Mb of the most distal region of 1p36 to design a microarray. The array includes 97 clones from 1p36, 41 clones from the subtelomeric regions of all human chromosomes, and three clones from each of the X and Y chromosomes. We used this microarray to study 25 subjects with well-characterized deletions of 1p36. All array CGH results agree with the deletion sizes and locations of the breakpoints in these subjects as determined previously by FISH and microsatellite analyses. Terminal deletions, interstitial deletions, derivative chromosomes and complex rearrangements were also identified. We anticipate that array CGH will change the diagnostic approach to many congenital and acquired genetic diseases such as mental retardation, birth defects and cancer.
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http://dx.doi.org/10.1093/hmg/ddg230DOI Listing
September 2003