John P Lydon

Molecular and Cellular Biology Program, Seattle, Washington, United States

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Publications (159)993 Total impact

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    ABSTRACT: Type II endometrial carcinomas (ECs) are estrogen independent, poorly differentiated tumors that behave in an aggressive manner. As TP53 mutation and CDH1 inactivation occur in 80% of human endometrial type II carcinomas, we hypothesized that mouse uteri lacking both Trp53 and Cdh1 would exhibit a phenotype indicative of neoplastic transformation. Mice with conditional ablation of Cdh1 and Trp53 (Cdh1(d/d)Trp53(d/d)) clearly demonstrate architectural features characteristic of type II ECs, including focal areas of papillary differentiation, protruding cytoplasm into the lumen (hobnailing) and severe nuclear atypia at 6 months of age. Further, Cdh1(d/d)Trp53(d/d) tumors in 12-month-old mice were highly aggressive, and metastasized to nearby and distant organs within the peritoneal cavity, such as abdominal lymph nodes, mesentery and peri-intestinal adipose tissues, demonstrating that tumorigenesis in this model proceeds through the universally recognized morphological intermediates associated with type II endometrial neoplasia. We also observed abundant cell proliferation and complex angiogenesis in the uteri of Cdh1(d/d)Trp53(d/d) mice. Our microarray analysis found that most of the genes differentially regulated in the uteri of Cdh1(d/d)Trp53(d/d) mice were involved in inflammatory responses. CD163 and Arg1, markers for tumor-associated macrophages, were also detected and increased in the uteri of Cdh1(d/d)Trp53(d/d) mice, suggesting that an inflammatory tumor microenvironment with immune cell recruitment is augmenting tumor development in Cdh1(d/d)Trp53(d/d) uteri. Further, inflammatory mediators secreted from CDH1-negative, TP53 mutant endometrial cancer cells induced normal macrophages to express inflammatory-related genes through activation of nuclear factor-κB signaling. These results indicate that absence of CDH1 and TP53 in endometrial cells initiates chronic inflammation, promotes tumor microenvironment development following the recruitment of macrophages and promotes aggressive ECs.Oncogene advance online publication, 7 July 2014; doi:10.1038/onc.2014.193.
    Oncogene 07/2014; · 8.56 Impact Factor
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    ABSTRACT: Coordinated uterine-embryonic axis formation and decidual remodeling are hallmarks of mammalian post-implantation embryo development. Embryonic-uterine orientation is determined at initial implantation and synchronized with decidual development. However, the molecular mechanisms controlling these events remain elusive despite its discovery a long time ago. In the present study, we found that uterine-specific deletion of Rbpj, the nuclear transducer of Notch signaling, resulted in abnormal embryonic-uterine orientation and decidual patterning at post-implantation stages, leading to substantial embryo loss. We further revealed that prior to embryo attachment, Rbpj confers on-time uterine lumen shape transformation via physically interacting with uterine estrogen receptor (ERα) in a Notch pathway-independent manner, which is essential for the initial establishment of embryo orientation in alignment with uterine axis. While at post-implantation stages, Rbpj directly regulates the expression of uterine matrix metalloproteinase in a Notch pathway-dependent manner, which is required for normal post-implantation decidual remodeling. These results demonstrate that uterine Rbpj is essential for normal embryo development via instructing the initial embryonic-uterine orientation and ensuring normal decidual patterning in a stage-specific manner. Our data also substantiate the concept that normal mammalian embryonic-uterine orientation requires proper guidance from developmentally controlled uterine signaling.Cell Research advance online publication 27 June 2014; doi:10.1038/cr.2014.82.
    Cell Research 06/2014; · 10.53 Impact Factor
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    ABSTRACT: Infertility and adverse gynecological outcomes such as preeclampsia and miscarriage represent significant female reproductive health concerns. The spatiotemporal expression of growth factors indicates that they play an important role in pregnancy. The goal of this study is to define the role of the ERBB family of growth factor receptors in endometrial function. Using conditional ablation in mice and siRNA in primary human endometrial stromal cells, we identified the epidermal growth factor receptor (Egfr) to be critical for endometrial function during early pregnancy. While ablation of Her2 or Erbb3 led to only a modest reduction in litter size, mice lacking Egfr expression are severely subfertile. Pregnancy demise occurred shortly after blastocyst implantation due to defects in decidualization including decreased proliferation, cell survival, differentiation and target gene expression. To place Egfr in a genetic regulatory hierarchy, transcriptome analyses was used to compare the gene signatures from mice with conditional ablation of Egfr, wingless-related MMTV integration site 4 (Wnt4) or boneless morphogenic protein 2 (Bmp2); revealing that not only are Bmp2 and Wnt4 key downstream effectors of Egfr, but they also regulate distinct physiological functions. In primary human endometrial stromal cells, marker gene expression, a novel high content image-based approach and phosphokinase array analysis were used to demonstrate that EGFR is a critical regulator of human decidualization. Furthermore, inhibition of EGFR signaling intermediaries WNK1 and AKT1S1, members identified in the kinase array and previously unreported to play a role in the endometrium, also attenuate decidualization. These results demonstrate that EGFR plays an integral role in establishing the cellular context necessary for successful pregnancy via the activation of intricate signaling and transcriptional networks, thereby providing valuable insight into potential therapeutic targets.
    PLoS Genetics 06/2014; 10(6):e1004451. · 8.52 Impact Factor
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    ABSTRACT: Recent data from human and mouse studies strongly support an indispensable role for Steroid Receptor Coactivator-2 (SRC-2)--a member of the p160/SRC family of coregulators--in progesterone-dependent endometrial stromal cell decidualization, an essential cellular transformation process that regulates invasion of the developing embryo into the maternal compartment. To identify the key progesterone-induced transcriptional changes that are dependent on SRC-2 and required for endometrial decidualization, we performed comparative genome-wide transcriptional profiling of endometrial tissue RNA from ovariectomized SRC-2(flox/flox) (SRC-2(f/f) (control)) and PR(cre/+)/SRC-2(flox/flox) (SRC-2(d/d) (SRC-2 depleted)) mice, acutely treated with vehicle or progesterone. Although data mining revealed that only a small subset of the total progesterone-dependent transcriptional changes is dependent on SRC-2 (~13%), key genes previously reported to mediate progesterone-driven endometrial stromal cell decidualization are present within this subset. Along with providing a more detailed molecular portrait of the decidual transcriptional program governed by SRC-2, the degree of functional diversity of these progesterone mediators underscores the pleiotropic regulatory role of SRC-2 in this tissue. To showcase the utility of this powerful informational resource to uncover novel signaling paradigms, we stratified the total SRC-2 dependent subset of progesterone-induced transcriptional changes in terms of novel gene expression and identified transcription factor 23 (Tcf23), a basic-helix-loop-helix transcription factor, as a new progesterone-induced target gene that requires SRC-2 for full induction. Importantly, using primary human endometrial stromal cells in culture, we demonstrate that TCF23 function is essential for progesterone-dependent decidualization, providing crucial translational support for this transcription factor as a new decidual mediator of progesterone action.
    Biology of Reproduction 02/2014; · 4.03 Impact Factor
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    ABSTRACT: The pathogenesis of endometriosis remains unclear, and relatively little is known about the mechanisms that promote establishment and survival of the disease. Previously, we demonstrated that AKT activity was increased in endometriosis tissues and cells from ovarian endometriomas and that this increase promoted cell survival as well as decreased levels of progesterone receptor. The objective of this study was to demonstrate a role for AKT in the establishment of ectopic lesions. First, a dose-dependent inhibition of AKT in stromal cells from human ovarian endometriomas (OSIS) as well as endometrial stromal cells from disease-free patients (ESC) with the allosteric AKT inhibitor MK-2206 was demonstrated by decreased levels of phosphorylated (p)(Ser473)-AKT. Levels of the AKT target protein, p(Ser256)-FOXO1 were increased in OSIS cells, which decreased with MK-2206 treatment, whereas levels of p(Ser9)-GSK3β did not change in response to MK-2206. Although MK-2206 decreased viability of both OSIS and ESC in a dose-dependent manner, proliferation of OSIS cells was differentially decreased significantly compared with ESC. Next, the role of hyperactive AKT in the establishment of ectopic lesions was studied using the bigenic, PR(cre/+) Pten(f/+) heterozygous mouse. Autologous implantation of uterine tissues was performed in these mice. After 4 weeks, an average of 4 ± 0.33 lesions per Pten(f/+) mouse and 7.5 ± 0.43 lesions in the PR(cre/+)Pten(f/+) mouse were found. Histological examination of the lesions showed endometrial tissue-like morphology, which was similar in both the Pten(f/+) and PR(cre/+)Pten(f/+) mice. Treatment of mice with MK-2206 resulted in a significantly decreased number of lesions established. Immunohistochemical staining of ectopic lesions revealed decreased p(Ser473)-AKT and the proliferation marker Ki67 from MK-2206-treated mice compared with vehicle-treated mice. Furthermore, levels of FOXO1 and progesterone receptor increased in lesions of mice receiving MK-2206. These results demonstrate that heightened AKT activity plays an active role in the establishment of ectopic endometrial tissues.
    Endocrinology 02/2014; · 4.72 Impact Factor
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    ABSTRACT: Ovarian cancer is the deadliest gynecological malignancy in Western countries. Early detection, however, is hampered by the fact that the origin of ovarian cancer is still unclear. Knowing that in a high percentage of endometrioid ovarian cancers Wnt/β-catenin signaling is activated, and in view of the hypothesis that ovarian cancer may originate from the distal oviduct, we studied mice in which Wnt/β-catenin signaling was activated in Müllerian duct derived tissues. Conditional Apc knockout mice were used to study activation of Wnt/β-catenin signaling in Müllerian duct derived organs. These Pgr(Cre/+) ;Apc(ex15lox/lox) mice (n=44) were sacrificed at 10, 20, 40 and 80 weeks and uterus, oviduct, ovaries and surrounding fat tissues were assessed using immunohistochemistry. Using nuclear β-catenin staining, Wnt/β-catenin signaling activation was confirmed in the entire epithelium of the adult Müllerian duct (fimbriae, oviduct, endometrium), but was absent from ovarian surface epithelium cells (OSEs). Besides endometrial hyperplasia, in 87,2% of mice intraepithelial lesions of the distal oviduct were found, while OSEs remained unaffected. In addition, 62,5% of mice developed tumors in the distal and fimbrial part of the oviduct. In the ovaries, mainly at young age, in 16,3% of mice, simple epithelial cysts were noted, which developed further into endometrioid ovarian tumors, resembling human endometrioid ovarian cancer (27,9% of mice). Next to this, loco-regional growth in the utero-ovarian ligament was also shown. Here, for the first time, mutations (activation of Wnt/β-catenin) in the distal oviduct result in precursor lesions that develop into ovarian tumors resembling human endometrioid ovarian cancer. © 2014 Wiley Periodicals, Inc.
    International Journal of Cancer 01/2014; · 6.20 Impact Factor
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    ABSTRACT: Breast cancer (BCa) molecular subtypes include luminal A, luminal B, normal-like, HER-2–enriched, and basal-like tumors, among which luminal B and basal-like cancers are highly aggressive. Biochemical pathways associated with patient survival or treatment response in these more aggressive subtypes are not well understood. With the limited availability of pathologically verified clinical specimens, cell line models are routinely used for pathway-centric studies. We measured the metabolome of luminal and basal-like BCa cell lines using mass spectrometry, linked metabolites to biochemical pathways using Gene Set Analysis, and developed a novel rank-based method to select pathways on the basis of their enrichment in patient-derived omics data sets and prognostic relevance. Key mediators of the pathway were then characterized for their role in disease progression. Pyrimidine metabolism was altered in luminal versus basal BCa, whereas the combined expression of its associated genes or expression of one key gene, ribonucleotide reductase subunit M2 (RRM2) alone, associated significantly with decreased survival across all BCa subtypes, as well as in luminal patients resistant to tamoxifen. Increased RRM2 expression in tamoxifen-resistant patients was verified using tissue microarrays, whereas the metabolic products of RRM2 were higher in tamoxifen-resistant cells and in xenograft tumors. Both genetic and pharmacological inhibition of this key enzyme in tamoxifen-resistant cells significantly decreased proliferation, reduced expression of cell cycle genes, and sensitized the cells to tamoxifen treatment. Our study suggests for evaluating RRM2-associated metabolites as noninvasive markers for tamoxifen resistance and its pharmacological inhibition as a novel approach to overcome tamoxifen resistance in BCa.
    Neoplasia. 01/2014; 16(5):390–402.
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    ABSTRACT: As pleiotropic coregulators, members of the p160/steroid receptor coactivator (SRC) family control a broad spectrum of transcriptional responses that underpin a diverse array of physiological and pathophysiological processes. Because of their potent coregulator properties, strict controls on SRC expression levels are required to maintain normal tissue functionality. Accordingly, an unwarranted increase in the cellular levels of SRC members has been causally linked to the initiation and/or progression of a number of clinical disorders. Although knockout mouse models have underscored the critical non-redundant roles for each SRC member in vivo, there are surprisingly few mouse models that have been engineered to overexpress SRCs. This deficiency is significant since SRC involvement in many of these disorders is based on unscheduled increases in the levels (rather than the absence) of SRC expression. To address this deficiency, we used recent mouse technology that allows for the targeted expression of human SRC-2 in cells which express the progesterone receptor. Through cre-loxP recombination driven by the endogenous progesterone receptor promoter, a marked elevation in expression levels of human SRC-2 was achieved in endometrial cells that are positive for the progesterone receptor. As a result of this increase in coregulator expression, female mice are severely subfertile due to a dysfunctional uterus, which exhibits a hypersensitivity to estrogen exposure. Our findings strongly support the proposal from clinical observations that increased levels of SRC-2 are causal for a number of endometrial disorders which compromise fertility. Future studies will use this mouse model to decipher the molecular mechanisms that underpin the endometrial defect. We believe such mechanistic insight may provide new molecular descriptors for diagnosis, prognosis, and/or therapy in the clinical management of female infertility.
    PLoS ONE 01/2014; 9(6):e98664. · 3.53 Impact Factor
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    ABSTRACT: Here, we describe an approach wherein negative electrospray ionization mass spectrometry has used to understand the relative flux through phosphate containing metabolic intermediates associated with central carbon metabolism after administering cells with 13C-labeled substrates. The method was applied to examine the 13C incorporation through glycolysis in T47D breast cancer cells and showed reduction of glycolytic relative flux upon treatment with 2-Deoxyglucose. Copyright © 2013 John Wiley & Sons, Ltd.
    Biological Mass Spectrometry 12/2013; 48(12):1270-5. · 3.41 Impact Factor
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    ABSTRACT: Fibroblast growth factors (FGFs) and their receptors (FGFR) regulate luminal epithelial (LE) cell proliferation in the adult mouse uterus. This study tested the hypothesis that FGFR2 has a biological role in postnatal development and function of the uterus by conditionally deleting Fgfr2 after birth using progesterone receptor (Pgr)-Cre mice. Adult Fgfr2 mutant female mice were initially subfertile and became infertile with increasing parity. No defects in uterine gland development were observed in conditional Fgfr2 mutant mice. In the adult, Fgfr2 mutant mice possessed a histologically normal reproductive tract with the exception of the uterus. The luminal epithelium (LE) of the Fgfr2 mutant uterus was stratified, but no obvious histological differences were observed in the glandular epithelium, stroma or myometrium. Within the stratified LE, cuboidal basal cells were present and positive for basal cell markers (KRT14 and TRP63). Nulliparous bred Fgfr2 mutants contained normal numbers of blastocysts on Day 3.5 postmating, but the number of embryo implantation sites was substantially reduced on Day 5.5 postmating. These results support the idea that loss of FGFR2 in the uterus after birth alters its development, resulting in LE stratification and peri-implantation pregnancy loss.
    Biology of Reproduction 11/2013; · 4.03 Impact Factor
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    ABSTRACT: Implantation of a blastocyst in the uterus is a multistep process tightly controlled by an intricate regulatory network of interconnected ovarian, uterine, and embryonic factors. Bone morphogenetic protein (BMP) ligands and receptors are expressed in the uterus of pregnant mice, and BMP2 has been shown to be a key regulator of implantation. In this study, we investigated the roles of the BMP type 1 receptor, activin-like kinase 2 (ALK2), during mouse pregnancy by producing mice carrying a conditional ablation of Alk2 in the uterus (Alk2 cKO mice). In the absence of ALK2, embryos demonstrate delayed invasion into the uterine epithelium and stroma, and upon implantation, stromal cells fail to undergo uterine decidualization, resulting in sterility. Mechanistically, microarray analysis revealed that CCAAT/enhancer-binding protein β (Cebpb) expression is suppressed during decidualization in Alk2 cKO females. These findings and the similar phenotypes of Cebpb cKO and Alk2 cKO mice lead to the hypothesis that BMPs act upstream of CEBPB in the stroma to regulate decidualization. To test this hypothesis, we knocked down ALK2 in human uterine stromal cells (hESC) and discovered that ablation of ALK2 alters hESC decidualization and suppresses CEBPB mRNA and protein levels. Chromatin immunoprecipitation (ChIP) analysis of decidualizing hESC confirmed that BMP signaling proteins, SMAD1/5, directly regulate expression of CEBPB by binding a distinct regulatory sequence in the 3' UTR of this gene; CEBPB, in turn, regulates the expression of progesterone receptor (PGR). Our work clarifies the conserved mechanisms through which BMPs regulate peri-implantation in rodents and primates and, for the first time, uncovers a linear pathway of BMP signaling through ALK2 to regulate CEBPB and, subsequently, PGR during decidualization.
    PLoS Genetics 11/2013; 9(11):e1003863. · 8.52 Impact Factor
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    ABSTRACT: Author Summary Failure of an embryo to correctly implant into the endometrium is a common cause of pregnancy failure or early embryo miscarriage. Although advances in our understanding of oocyte and embryo development have significantly increased pregnancy success rates, these rates remain unacceptably low due in part to an endometrium that is unreceptive to embryo implantation. Using experimental mouse genetics and a primary human cell culture model, we show here that the development of a receptive endometrium requires steroid receptor coactivator-2, a factor which modulates the response of an endometrial cell to the pregnancy hormone, progesterone. Specifically, we show that SRC-2 increases progesterone-dependent glycolysis in the endometrial cell to provide energy and biomolecules for the next round of cell division. For an endometrium to be receptive to embryo implantation, specific endometrial cells (termed stromal cells) need to divide and numerically increase just prior to devel
    PLoS Genet. 10/2013; 9(10):e1003900.
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    ABSTRACT: Early embryo miscarriage is linked to inadequate endometrial decidualization, a cellular transformation process that enables deep blastocyst invasion into the maternal compartment. Although much of the cellular events that underpin endometrial stromal cell (ESC) decidualization are well recognized, the individual gene(s) and molecular pathways that drive the initiation and progression of this process remain elusive. Using a genetic mouse model and a primary human ESC culture model, we demonstrate that steroid receptor coactivator-2 (SRC-2) is indispensable for rapid steroid hormone-dependent proliferation of ESCs, a critical cell-division step which precedes ESC terminal differentiation into decidual cells. We reveal that SRC-2 is required for increasing the glycolytic flux in human ESCs, which enables rapid proliferation to occur during the early stages of the decidualization program. Specifically, SRC-2 increases the glycolytic flux through induction of 6-phosphofructo-2-kinase/fructose-2, 6-bisphosphatase 3 (PFKFB3), a major rate-limiting glycolytic enzyme. Similarly, acute treatment of mice with a small molecule inhibitor of PFKFB3 significantly suppressed the ability of these animals to exhibit an endometrial decidual response. Together, these data strongly support a conserved mechanism of action by which SRC-2 accelerates the glycolytic flux through PFKFB3 induction to provide the necessary bioenergy and biomass to meet the demands of a high proliferation rate observed in ESCs prior to their differentiation into decidual cells. Because deregulation of endometrial SRC-2 expression has been associated with common gynecological disorders of reproductive-age women, this signaling pathway, involving SRC-2 and PFKFB3, promises to offer new clinical approaches in the diagnosis and/or treatment of a non-receptive uterus in patients presenting idiopathic infertility, recurrent early pregnancy loss, or increased time to pregnancy.
    PLoS Genetics 10/2013; 9(10):e1003900. · 8.52 Impact Factor
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    ABSTRACT: Uterine glands and their secretions are indispensable for endometrial function and fertility; however, the mechanisms regulating their development and function are not well understood. Forkhead transcription factor box A2 (FOXA2) is uniquely expressed in the glandular epithelial (GE) cells of the uterus, and conditional deletion of Foxa2 after birth impedes uterine gland development. An integrative approach was used here to define the FOXA2 cistrome in the murine uterus. Genome-wide mapping of FOXA2 binding sites was combined with transcriptomic analyses of isolated GE and Foxa2-deleted uteri. ChIP-Seq analyses found the number of FOXA2 target genes was substantially greater in the adult (8893) than neonatal uterus (1101). In the neonatal uterus, FOXA2-bound and GE-expressed genes (469) were enriched for developmentally related processes, including cell cycle, cell junction, focal adhesion, and WNT signaling. In the adult uterus, FOXA2-bound and GE-expressed genes (3730) were enriched for functional processes, including metabolic pathways, focal adhesion, bacterial invasion of epithelial cells, and WNT signaling. Analysis of the uterine FOXA2 cistrome provides novel insights into mechanisms governing endometrial gland development and function, which are important to understand fundamental aspects of uterine differentiation, regeneration and disease.- Filant, J., Lydon, J. P., Spencer, T. E. Integrated chromatin immunoprecipitation sequencing and microarray analysis identifies FOXA2 target genes in the glands of the mouse uterus.
    The FASEB Journal 09/2013; · 5.70 Impact Factor
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    ABSTRACT: Progesterone (P4) stimulates proliferation of the mammary epithelium by a mechanism that involves paracrine signaling mediated from progesterone receptor (PR) positive to neighboring PR negative cells. Here we used a primary mouse mammary epithelial cell (MEC) culture system to define the molecular mechanism by which P4 regulates the expression of target gene effectors of proliferation including the paracrine factor RANKL. MECs from adult virgin mice grown and embedded in 3D basement-membrane medium resemble mammary ducts in vivo structurally and with respect to other properties including a heterogeneous pattern of PR expression, P4 induction of RANKL and other target genes in a PR-dependent manner, and a proliferative response to progestin. RANKL was demonstrated to have multiple functional P4 responsive enhancers that bind PR in a hormone dependent manner as detected by chromatin immunoprecipitation (ChIP) assay. P4 also stimulated recruitment of Stat5a to RANKL enhancers through an apparent tethering with PR. Analysis of primary MECs from Stat5a knockout mice revealed that P4 induction of RANKL and a broad range of other PR target genes required Stat5a, as did P4 stimulated cell proliferation. In the absence of Stat5a, PR binding was lost at selective RANKL enhancers, but was retained with others suggesting that Stat5a acts to facilitate PR DNA binding at selective sites and to function as a co-activator with DNA bound PR at others. These results show that RANKL is a direct PR target gene and that Stat5a has a novel role as a co-factor in PR-mediated transcriptional signaling in the mammary gland.
    Molecular Endocrinology 09/2013; · 4.75 Impact Factor
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    ABSTRACT: Human papillomavirus is the main cause of cervical cancer, yet other nonviral cofactors are also required for the disease. The uterine cervix is a hormone-responsive tissue, and female hormones have been implicated in cervical carcinogenesis. A transgenic mouse model expressing human papillomavirus oncogenes E6 and/or E7 has proven useful to study a mechanism of hormone actions in the context of this common malignancy. Estrogen and estrogen receptor α are required for the development of cervical cancer in this mouse model. Estrogen receptor α is known to up-regulate expression of the progesterone receptor, which, on activation by its ligands, either promotes or inhibits carcinogenesis, depending on the tissue context. Here, we report that progesterone receptor inhibits cervical and vaginal epithelial cell proliferation in a ligand-dependent manner. We also report that synthetic progestin medroxyprogesterone acetate promotes regression of cancers and precancerous lesions in the female lower reproductive tracts (ie, cervix and vagina) in the human papillomavirus transgenic mouse model. Our results provide the first experimental evidence that support the fact that progesterone signaling is inhibitory for cervical carcinogenesis in vivo.
    American Journal Of Pathology 09/2013; · 4.60 Impact Factor
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    ABSTRACT: The features and regulation of uterine angiogenesis and vascular remodeling during pregnancy are poorly defined. Here we show that dynamic and variable decidual angiogenesis (sprouting, intussusception, and networking), and active vigorous vascular remodeling such as enlargement and elongation of "vascular sinus folding" (VSF) and mural cell drop-out occur distinctly in a spatiotemporal manner in the rapidly growing mouse uterus during early pregnancy-just after implantation but before placentation. Decidual angiogenesis is mainly regulated through VEGF-A secreted from the progesterone receptor (PR)-expressing decidual stromal cells which are largely distributed in the anti-mesometrial region. In comparison, P4 -PR-regulated VEGF-A-VEGFR2 signaling, ligand-independent VEGFR3 signaling, and uterine natural killer cells positively and coordinately regulate enlargement and elongation of VSF. During the postpartum period, Tie2 signaling could be involved in vascular maturation at the endometrium in a ligand-independent manner, with marked reduction of VEGF-A, VEGFR2 and PR expressions. Overall, we show that two key vascular growth factor receptors - VEGFR2 and Tie2 - strikingly but differentially regulate decidual angiogenesis and vascular remodeling in rapidly growing and regressing uteri in an organotypic manner.
    EMBO Molecular Medicine 07/2013; · 7.80 Impact Factor
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    ABSTRACT: Lymphangioleiomyomatosis (LAM) is a rare disease characterized by proliferation of abnormal smooth-muscle cells in the lungs, leading to functional loss and sometimes lung transplantation. While the origin of LAM cells is unknown, several features of LAM provide clues. First, LAM cells contain inactivating mutations in genes encoding Tsc1 or Tsc2, proteins that limit mTORC1 activity. Second, LAM tumors recur after lung transplantation, suggesting a metastatic pathogenesis. Third, LAM is found almost exclusively in women. Finally, LAM shares features with uterine leiomyomas, benign tumors of myometrial cells. From these observations, we proposed that LAM cells might originate from uterine leiomyomas containing Tsc mutations. To test our hypothesis, and to develop mouse models for leiomyoma and LAM, we targeted Tsc2 deletion primarily in uterine cells. In fact, nearly 100% of uteri from uterine-specific Tsc2 knockout mice developed myometrial proliferation and uterine leiomyomas by 12 and 24 weeks, respectively. Myometrial proliferation and mTORC1/S6 activity were abrogated by the mTORC1 inhibitor rapamycin or by elimination of sex steroid production through ovariectomy or aromatase inhibition. In ovariectomized Tsc2 null mice, mTORC1/S6 activity and myometrial growth were restored by estrogen but not progesterone. Thus, even without Tsc2, estrogen appears to be required for myometrial mTORC1/S6 signaling and proliferation. Finally, we found Tsc2 null myometrial tumors in lungs of older Tsc2 uterine-specific knockout females, suggesting that lung LAM-like myometrial lesions may indeed originate from the uterus. This mouse model may improve our understanding of LAM and leiomyomas, and might lead to novel therapeutic strategies for both diseases.
    Molecular Endocrinology 07/2013; · 4.75 Impact Factor
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    ABSTRACT: Successful pregnancy requires coordination of an array of signals and factors from multiple tissues. One such element, liver receptor homolog-1 (Lrh-1), is an orphan nuclear receptor that regulates metabolism and hormone synthesis. It is strongly expressed in granulosa cells of ovarian follicles and in the corpus luteum of rodents and humans. Germline ablation of Nr5a2 (also called Lrh-1), the gene coding for Lrh-1, in mice is embryonically lethal at gastrulation. Depletion of Lrh-1 in the ovarian follicle shows that it regulates genes required for both steroid synthesis and ovulation. To study the effects of Lrh-1 on mouse gestation, we genetically disrupted its expression in the corpus luteum, resulting in luteal insufficiency. Hormone replacement permitted embryo implantation but was followed by gestational failure with impaired endometrial decidualization, compromised placental formation, fetal growth retardation and fetal death. Lrh-1 is also expressed in the mouse and human endometrium, and in a primary culture of human endometrial stromal cells, reduction of NR5A2 transcript abundance by RNA interference abrogated decidualization. These findings show that Lrh-1 is necessary for maintenance of the corpus luteum, for promotion of decidualization and for formation of the placenta. It therefore has multiple, indispensible roles in establishing and sustaining pregnancy.
    Nature medicine 06/2013; · 27.14 Impact Factor
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    ABSTRACT: Endometrial cancer is closely associated with endometrial hyperplasia, unopposed estrogen exposure, and genetic alterations. However, the exact cause of endometrial cancer is still unknown. We previously identified mitogen inducible gene 6 (Mig-6) as an important mediator of progesterone signaling in uterus. Tumor suppressor function of progesterone, acting through Mig-6, coordinates endometrial stromal-epithelial communication. The expression of Mig-6 in these cellular compartments is under tight temporal and endocrine control. Here, the role of Mig-6 in the uterine epithelium was defined using floxed Mig-6 (Mig-6(f/f)) mice crossed to Wnt7a-Cre mice (Wnt7a(cre+) Mig-6(f/f)). Wnt7a(cre+) Mig-6(f/f) mice developed endometrial hyperplasia and estrogen-dependent endometrial cancer. Wnt7a(cre+) Mig-6(f/f) mice significantly increased proliferation in epithelial cells as well as apoptosis in sub-epithelial stroma cells. The expression of NOTCH1 and BIRC3 were increased in epithelial cells of Wnt7a(cre+) Mig-6(f/f) mice whereas PR levels were decreased in stromal cells. Progesterone therapy has been shown to be effective in preventing endometrial cancer as well as controlling growth of the endometrium. However, the effectiveness of progesterone for women with endometrial cancer is less clear. The hyperplasia phenotype of Wnt7a(cre+) Mig-6(f/f) mice was prevented by progesterone treatment while PR(cre+) Mig-6(f/f) mice, ablation of Mig-6 in all compartments of the uterus, did not have any effects. We showed that activation of progesterone signaling in the stroma regulates proliferation and apoptosis via suppression of ERα signaling in epithelium. Thus, epithelial Mig-6 is a critical tumor suppressor involved in progesterone mediated protection against the development of endometrial cancer.
    Cancer Research 06/2013; · 9.28 Impact Factor

Publication Stats

6k Citations
993.00 Total Impact Points

Institutions

  • 2006–2014
    • Molecular and Cellular Biology Program
      Seattle, Washington, United States
    • Institut Clinique de la Souris
      Illkirch, Alsace, France
  • 1991–2014
    • Baylor College of Medicine
      • Department of Molecular & Cellular Biology
      Houston, Texas, United States
  • 2013
    • Erasmus MC
      Rotterdam, South Holland, Netherlands
    • Washington State University
      • Department of Animal Sciences
      Pullman, WA, United States
    • Michigan State University
      • Department of Obstetrics, Gynecology, and Reproductive Biology
      East Lansing, MI, United States
  • 2011
    • Cincinnati Children's Hospital Medical Center
      • Division of Reproductive Sciences
      Cincinnati, OH, United States
    • Erasmus Universiteit Rotterdam
      • Department of Obstetrics and Gynaecology
      Rotterdam, South Holland, Netherlands
    • University of Texas Health Science Center at Houston
      • Brown Foundation Institute of Molecular Medicine
      Houston, TX, United States
    • Texas A&M University
      • Department of Animal Science
      College Station, TX, United States
  • 2008
    • Mayo Foundation for Medical Education and Research
      Rochester, Michigan, United States
  • 2007–2008
    • Vanderbilt University
      • Department of Pediatrics
      Nashville, MI, United States
    • Texas A&M University System Health Science Center
      • Texas A&M Health Science Center
      Bryan, Texas, United States
  • 1998–2001
    • University of California, San Francisco
      • Department of Anatomy
      San Francisco, CA, United States
  • 1996
    • National Institutes of Health
      • Section on Developmental Biology
      Bethesda, MD, United States