ABSTRACT: Transcription profiling by array of human mammary epithelial cells (HMEC) stimulated with TNF vs. controls reveals TNF induces distinct expression programs
Project description:Transcription profiling by array of human umbilical vein endothelial cells (HUVEC) stimulated with TNF vs. controls reveals TNF induces distinct expression programs
Project description:Tumor necrosis factor alpha induces vascular permeability, playing an important role in inflammation. Also, TNF-induced vascular leakage is involved in the increased extravasation of nanoparticle formulated chemotherapeutics improving drug delivery and subsequently tumor response, and we found a positive correlation between the presence of pericytes in the tumor-associated vasculature and TNF-induced leakage. RNA sequencing and pathway analysis of TNF-stimulated versus non-stimulated pericytes and endothelial cells show significant upregulation of several pathways involving interferon regulating pathways with a high expression of CXCL10, also known as Interferon gamma-inducible protein 10 (IP-10) in TNF-stimulated pericytes. In addition, CXCL10 protein production was significantly increased in conditioned medium from TNF-exposed pericytes compared to the other conditions. In our animal studies, we observed that tumor types with high pericyte covered vessels show enhanced permeability when exposed to TNF, which can be blocked with a neutralizing CXCL10 antibody. Vice versa, tumors with vessels low in pericyte number do not respond to TNF, i.e., do not express elevated permeability. Importantly, this lack of pericyte coverage can be compensated by co-administration of CXCL10. Our finding reveals a mechanism where TNF induces CXCL10 release from pericytes, being at the basis of increased permeability and thus vascular leakage.
Project description:Immortalized non-cancerous human mammary epithelial cells (HMLE) were transfected to express the murine fusion protein Twist1-estrogen receptor(point mutation G525R) (HTER). Twist1-mediated gene expression is activated by stimulation with 4-hydroxytamoxifen for several days and induces an epithelial-mesenchymal transition (EMT) in HTER cells. In breast cancer, EMT equips cancer cells for metastasis and therapy resistance. As control, HTER cells were treated with vehicle (methanol). As additional controls, HMLE cells were stimulated with 4-hydroxytamoxifen or methanol, respectively. Prior to RNA sequencing, EMT-undergoing HTER cells were sorted by fluorescence-activated cell sorting (FACS) based on E-Cadherin and CD44 surface protein levels into three populations, epithelial (E), hybrid epithelial-mesenchymal (EM), and mesenchymal (M): E-Cadherin_high_CD44_low (E), E-Cadherin_medium_CD44_medium (EM), and E-Cadherin_low_CD44_high (M).
Project description:The aim of the project is to perform deep proteomic and phosphoproteomic profiling of luminal epithelial and myoepithelial cells from the mammary gland of young vs. older women.
Project description:Unraveling the complexity of transcriptional programs coded by different cell types has been one of the central goals of cell biology. Using genome-wide location analysis, we examined how two different cell types generate different responses to the NF-kappaB signaling pathway. We showed that, after tumor necrosis factor-alpha (TNF-alpha) treatment, NF-kappaB p65 subunit binds to distinct genome locations and subsequently induces different subsets of genes in human monocytic THP-1 cells versus HeLa cells . Interestingly, the differential p65 binding in two cell types correlates with pre-existing cell-type specific enhancers prior to TNF-alpha stimulation, marked by histone modifications. We also found that two transcription factors, PU.1 and C/EBPalpha, appear to synergistically mediate enhancer creation and affect NF-kappaB target selection in THP-1 cells. In HeLa cells, co-expression of PU.1 and C/EBPalpha conferred TNF-alpha responsiveness to a subset of THP-1 specific NF-kappaB target genes. These results suggest that the diversity of transcriptional programs in mammalian cells arises, at least in part, from pre-existing enhancers that are established by cell specific transcription factors. We used Affymetrix microarray (GPL570) to obtain gene expression data for THP1 and HeLa cells before and after TNF-alpha treatment.
Project description:<p>During rheumatoid arthritis (RA), TNF activates fibroblast-like synoviocytes (FLS) inducing in a temporal order a constellation of genes, which perpetuate synovial inflammation. Although the molecular mechanisms regulating TNF-induced transcription are well characterized, little is known about the impact of mRNA stability on gene expression and the impact of TNF on decay rates of mRNA transcripts in FLS. To address these issues we performed RNA sequencing and genome-wide analysis of the mRNA stabilome in RA FLS. We found that TNF induces a biphasic gene expression program: initially, the inducible transcriptome consists primarily of unstable transcripts but progressively switches and becomes dominated by very stable transcripts. This temporal switch is due to: a) TNF-induced prolonged stabilization of previously unstable transcripts that enables progressive transcript accumulation over days and b) sustained expression and late induction of very stable transcripts. TNF- induced mRNA stabilization in RA FLS occurs during the late phase of TNF response, is MAPK-dependent, and involves several genes with pathogenic potential such as IL6, CXCL1, CXCL3, CXCL8/IL8, CCL2, and PTGS2. These results provide the first insights into genome-wide regulation of mRNA stability in RA FLS and highlight the potential contribution of dynamic regulation of the mRNA stabilome by TNF to chronic synovitis.</p>
Project description:We previously showed that recombinant human chorionic gonadotropin (r-hCG) induces mammary gland differentiation and inhibits mammary tumorigenesis in rats. The present study investigates the impact of r-hCG on the stemness of mammary epithelial cells by using a rat model. We performed microarray analysis of RNA isolated from mammospheres formed by normal mammary epithelial cells extracted from rats treated for 21 days either with r-hCG or vehicle (control).