The Krüppel-like factor 9 (KLF9) network in HEC-1-A endometrial carcinoma cells suggests the carcinogenic potential of dys-regulated KLF9 expression

<p>Abstract</p> <p>Background</p> <p>Krüppel-like factor 9 (KLF9) is a transcriptional regulator of uterine endometrial cell proliferation, adhesion and differentiation; processes essential for pregnancy success and which are subverted during tumorigenesis. The network of endometrial genes controlled by KLF9 is largely unknown. Over-expression of KLF9 in the human endometrial cancer cell line HEC-1-A alters cell morphology, proliferative indices, and differentiation, when compared to KLF9 under-expressing HEC-1-A cells. This cell line provides a unique model for identifying KLF9 downstream gene targets and signaling pathways.</p> <p>Methods</p> <p>HEC-1-A sub-lines differing in relative levels of KLF9 were subjected to microarray analysis to identify differentially-regulated RNAs.</p> <p>Results</p> <p>KLF9 under-expression induced twenty four genes. The KLF9-suppressed mRNAs encode protein participants in: aldehyde metabolism (AKR7A2, ALDH1A1); regulation of the actin cytoskeleton and cell motility (e.g., ANK3, ITGB8); cellular detoxification (SULT1A1, ABCC4); cellular signaling (e.g., ACBD3, FZD5, RAB25, CALB1); and transcriptional regulation (PAX2, STAT1). Sixty mRNAs were more abundant in KLF9 over-expressing sub-lines. The KLF9-induced mRNAs encode proteins which participate in: regulation and function of the actin cytoskeleton (COTL1, FSCN1, FXYD5, MYO10); cell adhesion, extracellular matrix and basement membrane formation (e.g., AMIGO2, COL4A1, COL4A2, LAMC2, NID2); transport (CLIC4); cellular signaling (e.g., BCAR3, MAPKAPK3); transcriptional regulation [e.g., KLF4, NR3C1 (glucocorticoid receptor), RXRα], growth factor/cytokine actions (SLPI, BDNF); and membrane-associated proteins and receptors (e.g., CXCR4, PTCH1). In addition, the abundance of mRNAs that encode hypothetical proteins (KLF9-inhibited: C12orf29 and C1orf186; KLF9-induced: C10orf38 and C9orf167) were altered by KLF9 expression. Human endometrial tumors of high tumor grade had decreased KLF9 mRNA abundance.</p> <p>Conclusion</p> <p>KLF9 influences the expression of uterine epithelial genes through mechanisms likely involving its transcriptional activator and repressor functions and which may underlie altered tumor biology with aberrant KLF9 expression.</p

Insulin-like growth factor-I (IGF-I) and thioredoxin are differentially expressed along the reproductive tract of the ewe during the oestrous cycle and after ovariectomy

Insulin-like growth factor-I (IGF-I) and thioredoxin are regulated by gonadal steroids in the female reproductive tract of many species. Oestradiol regulates IGF-I and thioredoxin mRNA levels in the reproductive tract of prepubertal lambs. The physiological status (different endocrine environment) may affect the sensitivity of the reproductive tract to oestradiol and progesterone. We studied the effects of different endocrine milieus (late-follicular and luteal phases of the oestrous cycle, and ovariectomy before or after puberty) on the expression of IGF-I, thioredoxin, oestrogen receptor α (ERα) and progesterone receptor (PR) in sheep. The mRNA levels were determined by a solution hybridisation technique. In the uterus the levels of ERα, PR and thioredoxin mRNA were higher in the late-follicular phase group than in the other three groups, and IGF-I mRNA was high during both the late-follicular and the luteal phases. In the cervix only PR mRNA was significantly higher in the ewes in the late-follicular phase than in the other groups. In the oviducts the levels of thioredoxin and ERα mRNA were highest in the ovariectomised adult ewes, and thioredoxin mRNA was higher than the levels found in the ewes in the late-follicular phase. The IGF-I mRNA levels in the oviduct did not differ between any of the groups. The transcripts of IGF-I, thioredoxin, ERα and PR, varied according to the physiological status and also along the female reproductive tract, suggesting that the regulation of the mRNA levels of these factors by the steroid environment is tissue specific. Koncentrationen av insulin-like growth factor-I (IGF-I) och thioredoxin regleras hos många arter i honors reproduktionsorgan av könssteroider. Sålunda reglerar östradiol IGF-I och thioredoxin mRNA i reproduktionsorganen hos prepubertala lamm. Djurets fysiologiska status (dvs den endokrina miljön) kan påverka känsligheten hos reproduktionsorganen för östradiol och progesteron. Vi studerade effekterna av olika endokrina miljöer (sen follikelfas och lutealfas i östruscykeln, samt ovariektomi före och efter puberteten) på uttrycket av IGF-I, thioredoxin, östrogenreceptor α (ERα) och progesteronreceptorn (PR) hos får. Lösningshybridisering användes för att bestämma mRNA nivåerna. I livmodern var mRNA koncentrationen för ERα, PR och thioredoxin högre i sen follikelfas än i de andra tre grupperna och IGF-I mRNA nivån var hög både under sen follikelfas och i lutealfas. PR mRNA i cervix var signifikant högre hos tackorna under sen follikelfas än i de andra grupperna. I äggledarna var mRNA nivåerna av thioredoxin och ERα högst i de djur som ovariektomerats som vuxna, och thioredoxin mRNA var högre än hos tackorna under sen follikelfas. Det förelåg ingen skillnad vad gäller IGF-I mRNA nivåerna i äggledaren mellan någon av grupperna. IGF-I, thioredoxin, ERα och PR mRNA nivåerna varierade beroende på fysiologisk status och morfologisk lokalisation i reproduktionsorganen. Detta tyder på att steroidhormonernas reglering av dessa faktorers mRNA uttryck också är vävnadsspecifik

The planetary biology of cytochrome P450 aromatases

© 2004 Gaucher et al; licensee BioMed Central Ltd.The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1741-7007/2/19DOI: 10.1186/1741-7007-2-19Background. Joining a model for the molecular evolution of a protein family to the paleontological and geological records (geobiology), and then to the chemical structures of substrates, products, and protein folds, is emerging as a broad strategy for generating hypotheses concerning function in a post-genomic world. This strategy expands systems biology to a planetary context, necessary for a notion of fitness to underlie (as it must) any discussion of function within a biomolecular system. Results. Here, we report an example of such an expansion, where tools from planetary biology were used to analyze three genes from the pig Sus scrofa that encode cytochrome P450 aromatases–enzymes that convert androgens into estrogens. The evolutionary history of the vertebrate aromatase gene family was reconstructed. Transition redundant exchange silent substitution metrics were used to interpolate dates for the divergence of family members, the paleontological record was consulted to identify changes in physiology that correlated in time with the change in molecular behavior, and new aromatase sequences from peccary were obtained. Metrics that detect changing function in proteins were then applied, including KA/KS values and those that exploit structural biology. These identified specific amino acid replacements that were associated with changing substrate and product specificity during the time of presumed adaptive change. The combined analysis suggests that aromatase paralogs arose in pigs as a result of selection for Suoidea with larger litters than their ancestors, and permitted the Suoidea to survive the global climatic trauma that began in the Eocene. Conclusions. This combination of bioinformatics analysis, molecular evolution, paleontology, cladistics, global climatology, structural biology, and organic chemistry serves as a paradigm in planetary biology. As the geological, paleontological, and genomic records improve, this approach should become widely useful to make systems biology statements about high-level function for biomolecular systems

Abstract PD02-03: Regulation of Mammary Stem Cell Population with Dietary Intake of Soy Protein Isolate Reveals Novel Mechanisms for Diet-Mediated Control of Mammary Tumorigenesis

Abstract Breast cancer risk is highly modified by environmental factors including diet. Previously, we showed that dietary intake of soy protein isolate (SPI) decreased mammary tumor incidence and increased mammary tumor latency in rats relative to those fed a control casein (CAS) diet, when exposed to the chemical carcinogen NMU. Mammary tumor preventive effects by SPI were associated with up-regulation of the tumor suppressor PTEN and down-regulation of the oncogenic Wnt-signaling components in mammary epithelial cells (MECs) leading to enhanced differentiation. Given that breast cancer is considered to be initiated by stem cells (SCs) with tumorigenic potential, termed cancer stem cells (CSCs), and mammary over-expression of Wnt-1 in mice causes spontaneous breast tumors due to the expansion of mammary CSCs, we hypothesized that diet may alter the mammary SC population to effect mammary tumor prevention. Here, we investigated SPI effects relative to CAS, on mammary tumor development in MMTV-Wnt 1-Transgenic (Tg) female mice and on the mammary SC population in virgin wildtype (WT) and pre-neoplastic Tg female mice. Tumor incidence at 8 months of age of Tg mice fed SPI (n=30) post-weaning was lower than in those fed CAS (48.3% vs.73.5%; P&amp;lt;0.05) (n=34). Interestingly, tumor latency in SPI-fed Tg mice was shorter than for the CAS-fed group (4.65 vs. 5.88 months; P&amp;lt;0.05). Tumor weight and growth rate was similar for the diet groups. To evaluate SPI effects relative to CAS, on mammary SC population, epithelial cells from mammary tissues were isolated from WT (PND 100) and Tg (PND75) mice. The percentage of mammary SCs was quantified by fluorescence activated cell sorting analysis of MECs based on their expression of mouse mammary SC markers (CD29 and CD24) within the Lineage negative (Lin-) population (CD45-, TER119-, CD31-). The Lin-CD29hiCD24hi subpopulation in MECs was decreased by 50% in Tg mice fed SPI post-weaning relative to those fed CAS, decreasing the likelihood of mutations that convert normal to cancer SC and could explain the protective effects of SPI on tumor incidence. Interestingly, the SC population was expanded by 2-fold in MECs of WT mice fed SPI relative to the CAS group, which could be beneficial for mammary gland development and tissue homeostasis. Our findings provide the first report of dietary effects on the SC population in MECs in vivo. The dichotomy of SPI effects on tumor outcome in mammary tissues with dysregulated Wnt signaling maybe related to the loss of the complex regulatory grid between PTEN and Wnt/β-catenin pathways, both of which control stem cell fate. The possibility that diet can influence tumor progression at the level of the SC population suggests the important contribution of nutrition to the etiology of breast cancer and to the early management of breast health. Supported by USDA-ARS and Department of Defense Breast Cancer Research Program. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr PD02-03.</jats:p