Search

Bausero, P., M.-H. Ben-Mahdi, J.-P. Mazucatelli, C. Bloy, and M. Perrot-Applanat. Vascular endothelial growth factor is modulated in vascular muscle cells by estradiol, tamoxifen, and hypoxia. Am J Physiol Heart Circ Physiol 279: H2033-H2042, 2000.--Vascular endothelial growth factor (VEGF) promotes neovascularization, microvascular permeability, and endothelial proliferation. We described previously VEGF mRNA and protein induction by estradiol (E2) in human endometrial fibroblasts. We report here E2 induction of VEGF expression in human venous muscle cells [smooth muscle cells (SMC) from human saphenous veins; HSVSMC] expressing both ER-[Alpha] and ER-[Beta] estrogen receptors. E2 at [10.sup.-9] to [10.sup.-8] M increases VEGF mRNA in HSVSMC in a time-dependent manner (3-fold at 24 h), as analyzed by semiquantitative RT-PCR. This level of induction is comparable with E2 endometrial induction of VEGF mRNA. Tamoxifen and hypoxia also increase HSVSMC VEGF mRNA expression over control values. Immunocytochemistry of saphenous veins and isolated SMC confirms translation of VEGF mRNA into protein. Immunoblot analysis of HSVSMC-conditioned medium detects three bands of 18, 23, and 28 kDa, corresponding to VEGF isoforms of 121, 165, and 189 amino acids. Radioreceptor assay of the conditioned medium produced by E2-stimulated HSVSMC reveals an increased VEGF secretion. Our data indicate that VEGF is E2, tamoxifen, and hypoxia inducible in cultured HSVSMC and E2 inducible in aortic SMC, suggesting E2 modulation of VEGF effects in angiogenesis, vascular permeability, and integrity. saphenous vein; vascular smooth muscle cells; human

Exposure to low doses of environmental estrogens such as bisphenol A and genistein (G) alters mammary gland development. The effects of environmental anti-androgens, such as the fungicide vinclozolin (V), on mammary gland morphogenesis are unknown. We previously reported that perinatal exposure to G, V, and the GV combination causes histological changes in the mammary gland during the peripubertal period, suggesting alterations to the peripubertal hormone response. We now investigate whether perinatal exposure to these compounds alters the gene expression profiles of the developing glands to identify the dysregulated signaling pathways and the underlying mechanisms. G, V, or GV (1 mg/kg body weight per day) was added to diet of Wistar rats, from conception to weaning; female offspringmammary glands were collected at postnatal days (PNDs) 35 and 50. Genes displaying differential expression and belonging to different functional categories were validated by quantitative PCR and immunocytochemistry. At PND35, G had little effect; the slight changes noted were in genes related to morphogenesis. The changes following exposure to V concerned the functional categories associated with development (Cldn1, Krt17, and Sprr1a), carbohydrate metabolism, and steroidogenesis. The GV mixture upregulated genes (Krt17, Pvalb, and Tnni2) involved in muscle development, indicating effects on myoepithelial cells duringmammary glandmorphogenesis. Importantly, at PND50, cycling females exposed to GV showed an increase in the expression of genes (Csn2, Wap, and Elf5) related to differentiation, consistent with the previously reported abnormal lobuloalveolar development previously described. Thus, perinatal exposure to GV alters the mammary gland hormone response differently at PND35 (puberty) and in animals with established cycles. [ABSTRACT FROM AUTHOR]

Presents information on a study which investigated whether estradiol induces the production of vascular endothelial growth factor messenger RNA and protein in the smooth muscle cell from human saphenous veins and aorta. Methodology of the study; Results and discussion on the study.

The vast majority of gastric cancer (GC) cases are adenocarcinomas including intestinal and diffuse GC. The incidence of diffuse GC, often associated with poor overall survival, has constantly increased in Western countries. Epidemiological studies have reported increased mortality from GC after occupational exposure to pro-carcinogens that are metabolically activated by cytochrome P450 enzymes through aryl hydrocarbon receptor (AhR). However, little is known about the role of AhR and environmental AhR ligands in diffuse GC as compared to intestinal GC in Western patients. In a cohort of 29, we demonstrated a significant increase in AhR protein and mRNA expression levels in GCs independently of their subtypes and clinical parameters. AhR and RHOA mRNA expression were correlated in diffuse GC. Further, our study aimed to characterize in GC how AhR and the AhR-related genes cytochrome P450 1A1 (CYP1A1) and P450 1B1 (CYP1B1) affect the mRNA expression of a panel of genes involved in cancer development and progression. In diffuse GC, CYP1A1 expression correlated with genes involved in IGF signaling, epithelial-mesenchymal transition ( Vimentin ), and migration ( MMP2 ). Using the poorly differentiated KATO III epithelial cell line, two well-known AhR pollutant ligands, namely 2-3-7-8 tetrachlorodibenzo-p-dioxin (TCDD) and benzo[a]pyrene (BaP), strongly increased the expression of CYP1A1 and Interleukin1β ( IL1B ), and to a lesser extend UGT1 , NQO1, and AhR Repressor ( AhRR ). Moreover, the increased expression of CYP1B1 was seen in diffuse GC, and IHC staining indicated that CYP1B1 is mainly expressed in stromal cells. TCDD treatment increased CYP1B1 expression in KATO III cells, although at lower levels as compared to CYP1A1 . In intestinal GC, CYP1B1 expression is inversely correlated with several cancer-related genes such as IDO1 , a gene involved in the early steps of tryptophan metabolism that contributes to the endogenous AhR ligand kynurenine expression. Altogether, our data provide evidence for a major role of AhR in GC, as an environmental xenobiotic receptor, through different mechanisms and pathways in diffuse and intestinal GC. Our results support the continued efforts to clarify the identity of exogenous AhR ligands in diffuse GC in order to define new therapeutic strategies.

Gastric cancer (GC) is one of the major causes of cancer-related mortality worldwide. The vast majority of GC cases are adenocarcinomas including intestinal and diffuse GC. The incidence of diffuse GCs, often associated with poor overall survival, has constantly increased in USA and Europe The molecular basis of diffuse GC aggressivity remains unclear. Using mRNA from diffuse and intestinal GC tumor samples of a Western cohort, this study reports the expression level of the immunomodulatory aryl-hydrocarbon receptor (AhR), and genes involved in immune suppression ( PD1 , PD-L1 , PD-L2 ) and the early steps of tryptophan metabolism ( IDO1 , IDO2 , TDO2 ). Strongly increased expression of IDO1 ( p < 0.001) and PD1 ( p < 0.003) was observed in the intestinal sub-type. The highest expression of IDO1 and PDL1 correlated with early clinical stage and absence of lymphatic invasion (×25 p = 0.004, ×3 p = 0.04, respectively). Our results suggest that kynurenine, produced by tryptophan catabolism, and AhR activation play a central role in creating an immunosuppressive environment. Correspondingly, as compared to intestinal GCs, expression levels of IDO1-TDO2 and PD-L1 were less prominent in diffuse GCs which also had less infiltration of immune cells, suggesting an inactive immune response in the advanced diffuse GC. Confirmation of these patterns of gene expression will require a larger cohort of early and advanced stages of diffuse GC samples.

The greater omentum represents a specific adipose tissue resected with gastric surgery for cancer. Diffuse gastric adenocarcinoma (diffuse-GC) is of major relevance among gastric cancers due to its unknown origin, aggressiveness, and metastasis in the peritoneal cavity. We postulated that persistent organic pollutants (POPs) could be detected in the greater omentum. Great omentum from patients with (i) diffuse-GC, or (ii) with other peritoneal metastatic cancer, and (iii) control group without cancer disease were analyzed for the distribution of a large panel of 96 POPs. POPs include polychlorinated dioxins/furans (PCDD/Fs), polychlorobiphenyls (PCBs), polybrominated diphenyl ethers (PBDE), polybrominated biphenyls (PBB), hexabromocyclododecanes, organochlorine pesticides, and polycyclic aromatic hydrocarbons (PAHs). The widespread presence of a substantial list of POPs (PCDDs/Fs, PCBs, and brominated flame retardants) was found in the omentum from patients with aggressive diffuse-GC, with minor presence of some organochlorine pesticides and PAHs at the low analyzed levels. Some chemicals appeared in larger concentrations in diffuse-GC or other cancer groups, including some PCDDs, PCB105, 123, 138, PBDE209, and PBB153. Overall, the present pilot study provides novel information regarding POPs levels in the omental fat, which is an understudied fat depot in terms of POPs load, and diffuse-GC association.

Gastric cancer (GC) is a highly heterogeneous disease and one of the major causes of cancer-related mortality worldwide. Diffuse-type gastric adenocarcinoma (or poorly cohesive- with independent cells) is characterized by aggressive behavior (rapid invasion, chemoresistance and peritoneal metastasis), as compared with intestinal-subtype adenocarcinoma. Diffuse subtype GC additionally has a substantially increasing incidence rate in Europe and the USA, and was often associated with younger age. Our objective was to analyze the expression and clinical significance of genes involved in several signaling pathways in diffuse-type GC. Tumors samples and non-malignant gastric tissues were obtained from patients with GC (diffuse-type and intestinal-subtype adenocarcinoma). The expression of 33 genes coding for proteins involved in four categories, growth factors and receptors, epithelial-mesenchymal transition, cell proliferation and migration, and angiogenesis was determined by reverse transcription-quantitative polymerase chain reaction. The expression of 22 genes was significantly upregulated in diffuse-type GC and two were downregulated (including CDH1 ) compared with normal tissues. Among these genes, acompared with intestinal-subtype adenocarcinoma, diffuse-type GC revealed elevated levels of IGF1 and IGF1R, FGF7 and FGFR1, ZEB2, CXCR4, CXCL12 and RHOA , and decreased levels of CDH1, MMP9 and MKI67 . The expression of selected genes was compared with other genes and according to clinical parameters. Furthermore, TGF-β expression was significantly increased in linitis, a sub-population of diffusely infiltrating type associated with extensive fibrosis and tumor invasion. Our study identified new target genes ( IGF1, FGF7, CXCR4, TG-β and ZEB2 ) whose expression is associated with aggressive phenotype of diffuse-type GC.

The development and function of the mammary gland are endocrine-dependent processes, depending on the stage of development. Foetal and/or postnatal exposure to low doses of BPA alters tissue organisation through epithelial proliferation and stroma-epithelial interactions. BPA also alters the expression of E2-dependent epithelial and stroma transcriptomes. Several signalling pathways are consistent with the observed phenotype: proliferation and apoptosis, a focal adhesion pathway indicating changes in biomechanical properties of the extracellular matrix, and immune function. Some of BPA's effects are reversed by oestrogen and/or GPER inhibitors. BPA also alters the expression of epigenetic marks (EZH2, HOTAIR), which would explain the delayed effect of foetal BPA exposure. In conclusion, experimental evidence shows that pre- or postnatal BPA exposure consistently causes endocrine modifications in the mammary tissue of different animal species, disrupting stromal-epithelial interactions and ultimately increasing its susceptibility to carcinogens. An interspecies comparison highlights why and how these effects apply to humans., (Copyright © 2018. Published by Elsevier B.V.)

Increasing epidemiological and animal experimental data provide substantial support for the role of aryl hydrocarbon receptor (AhR) in mammary tumorigenesis. The effects of AhR have been clearly demonstrated in rodent models of breast carcinogenesis and in several established human breast cancer cell lines following exposure to AhR ligands or AhR overexpression. However, relatively little is known about the role of AhR in human breast cancers. AhR has always been considered to be a regulator of toxic and carcinogenic responses to environmental contaminants such as TCDD (dioxin) and benzo[a]pyrene (BaP). The aim of this study was to identify the type of breast tumors (ERα-positive or ERα-negative) that express AHR and how AhR affects human tumorigenesis. The levels of AHR, AHR nuclear translocator (ARNT) and AHR repressor (AHRR) mRNA expression were analyzed in a cohort of 439 breast tumors, demonstrating a weak association between high AHR expression and age greater than fifty years and ERα-negative status, and HR-/ERBB2 breast cancer subtypes. AHRR mRNA expression was associated with metastasis-free survival, while AHR mRNA expression was not. Immunohistochemistry revealed the presence of AhR protein in both tumor cells (nucleus and/or cytoplasm) and the tumor microenvironment (including endothelial cells and lymphocytes). High AHR expression was correlated with high expression of several genes involved in signaling pathways related to inflammation (IL1B, IL6, TNF, IL8 and CXCR4), metabolism (IDO1 and TDO2 from the kynurenine pathway), invasion (MMP1, MMP2 and PLAU), and IGF signaling (IGF2R, IGF1R and TGFB1). Two well-known ligands for AHR (TCDD and BaP) induced mRNA expression of IL1B and IL6 in an ERα-negative breast tumor cell line. The breast cancer ER status likely influences AhR activity involved in these signaling pathways. The mechanisms involved in AhR activation and target gene expression in breast cancers are also discussed.

Background: Vascular endothelial growth factor (VEGF) is a multifunctional cytokine that has important roles in angiogenesis. Our knowledge of the significance of VEGF isoforms in human cancer remains incomplete., Methods: Bioluminescence imaging and transcriptomic analysis were used to study the colonisation capacity of the human breast cancer cells MDA-MB-231 controlling or overexpressing the VEGF165 or VEGF189 isoform (named cV-B, V165-B and V189-B, respectively) in nude mice., Results: When injected into the bloodstream, V189-B cells induced less metastasis in the lungs and bone than V165-B and cV-B control cells, consistent with longer survival of these mice and delay in tumour uptake in the mice injected with a V189-B clone. Histological analysis confirmed that there were less αSMA-positive cells in the lungs of the mice injected with V189-B. In vitro V189-B cells decreased both cell invasion and survival. Using transcriptomic analysis, we identified a subset of 18 genes expressed differentially between V189 and V165 cell lines and in 120 human breast tumours. V165 was associated with poor prognosis, whereas V189 was not, suggesting a complex regulation by VEGF isoforms. Our results showed a negative correlation between the expression pattern of VEGF189 and the levels of expression of seven genes that influence metastasis., Conclusion: Our findings provide the first evidence that VEGF isoforms have different effects on breast cancer cell line colonisation in vivo.

Vascular endothelial growth factor A (VEGF-A) is well known for its key roles in blood vessel growth. Although most studies on VEGF and VEGF receptors have been focused on their functions in angiogenesis and in endothelial cells, the role of VEGF in cancer biology appears as an emerging area of importance. In this context, the presence of VEGF receptors in tumor cells strongly suggests that VEGF-A also promotes a wide range of functions, both in vitro and in vivo, all autocrine functions on tumor cells, including adhesion, survival, migration and invasion. Ultimately, refining our knowledge of VEGF signaling pathways in tumor cells should help us to understand why the current used treatments targeting the VEGF pathway in cancer are not universally effective in inhibiting metastasis tumors, and it should also provide new avenues for future therapies.

The impact of early exposure to endocrine disruptor mixtures on mammary gland development is poorly known. Here, we identify the effects of a conception to weaning exposure of rats to the phytoestrogen genistein (G) and/or the antiandrogen vinclozolin (V) at 1mg/kg-d, alone or in association. Using several approaches, we found that G- and GV-exposed rats displayed significantly greater epithelial branching and proliferation, wider terminal end buds than controls at PND35, as well as ductal hyperplasia and periductal fibrosis. Focal branching defects were present in V-exposed rats. An increased ER and AR expression was observed in G- and GV- as compared to V-exposed rats at PND35. Surprisingly, a significant number of GV- and to a lesser extent, V-exposed animals displayed abnormal hyperplasic alveolar structures at PND50. Thus, gestational and lactational exposure to low doses of genistein plus vinclozolin may seriously affect peripubertal development of the rat mammary gland., (Copyright © 2011 Elsevier Inc. All rights reserved.)

The existence of multiple VEGF-A isoforms raised the possibility that they may have distinct functions in tumor growth. We have previously published that VEGF189 and VEGF165 contribute to breast cancer progression and angiogenesis, but VEGF165 induced the most rapid tumor uptake. Since VEGF165 has been described as a survival factor for breast tumor cells, we questioned here the effects of VEGF189 on the survival/apoptosis of MDA-MB-231 cells. We used clones which overexpress VEGF189 (V189) or VEGF165 (V165) isoforms and compared them to a control one (cV). Overexpression of VEGF189 resulted in increased cell apoptosis, as determined by Annexin-V apoptosis assay, under serum starvation and doxorubicin treatment, while VEGF 165 was confirmed to be a survival factor. Since MDA-MB-231 highly express NRP1 (a co-receptor for VEGF-A), we used short hairpin RNA (shRNA) to knockdown NRP1 expression. V189shNRP1 clones were characterized by reduced apoptosis and higher necrosis, as compared to V189shCtl, under stress conditions. Unexpectedly, NRP1 knock-down had no effect on the survival or apoptosis of V165 cells. VEGF189 showed greater affinity towards NRP1 than VEGF165 using a BIAcore binding assay. Finally, since endogenously produced urokinase-type plasminogen (uPA) has been found to prevent apoptosis in breast cancers, we analyzed the level of uPA activity in our clones. An inhibition of uPA activity was observed in V189shNRP1 clones. Altogether, these results suggest a major role of NRP1 in apoptosis induced by VEGF189 in stress conditions and confirm VEGF165 as a survival factor.

Bisphenol A (BPA) is an estrogenic agonist compound that induces changes in diverse reproductive parameters in rats. The aim of the present study was to determine the effects of BPA given in drinking water containing 10mg/L (approximate dose 1.2mg/kg BW/day), administered chronically to rats during pregnancy and lactation, on reproductive tract parameters of the offspring. 79.2% of the female offspring from BPA-treated mothers presented irregular estrous cycles. As compared to the control group, a significant increase in the thickness of the uterine epithelia and stroma was observed in the BPA group. Additionally, 60% of the female offspring from BPA mothers did not undergo abundant uterine epithelial apoptosis during the estrus phase of the cycle while control animals did. In addition, a down regulation of ERα expression was observed in epithelial cells on estrus day. The results indicate that BPA, when administered chronically in water beverages to dams, modifies the reproductive cycle of the offspring during young adulthood., (Copyright © 2010 Elsevier Inc. All rights reserved.)

Background: Endothelial dysfunction has been implicated in the pathogenesis of diverse pathologies ranging from vascular and immune diseases to cancer. TNF-α is one of the mediators of endothelial dysfunction through the activation of transcription factors, including NF-κB. While HUVEC (macrovascular cells) have been largely used in the past, here, we documented an NF-κB gene signature in TNFα-stimulated microvascular endothelial cells HMEC often used in tumor angiogenesis studies., Methodology/principal Findings: We measured mRNA expression of 55 NF-κB related genes using quantitative RT-PCR in HUVEC and HMEC. Our study identified twenty genes markedly up-regulated in response to TNFα, including adhesion molecules, cytokines, chemokines, and apoptosis regulators, some of them being identified as TNF-α-inducible genes for the first time in endothelial cells (two apoptosis regulators, TNFAIP3 and TNFRSF10B/Trail R2 (DR5), the chemokines GM-CSF/CSF2 and MCF/CSF1, and CD40 and TNF-α itself, as well as NF-κB components (RELB, NFKB1 or 50/p105 and NFKB2 or p52/p100). For eight genes, the fold induction was much higher in HMEC, as compared to HUVEC. Most importantly, our study described for the first time a connection between NF-κB activation and the induction of most, if not all, of these genes in HMEC as evaluated by pharmacological inhibition and RelA expression knock-down by RNA interference. Moreover, since TNF-α is highly expressed in tumors, we further applied the NF-κB gene signature documented in TNFα-stimulated endothelial cells to human breast tumors. We found a significant positive correlation between TNF and the majority (85 %) of the identified endothelial TNF-induced genes in a well-defined series of 96 (48 ERα positive and 48 ERα negative) breast tumors., Conclusion/significance: Taken together these data suggest the potential use of this NF-κB gene signature in analyzing the role of TNF-α in the endothelial dysfunction, as well as in breast tumors independently of the presence of ERα.