Analysis of HeLa cells following depletion of BRCA1 tumor supressor using RNAi against BRCA1. Results provide insight into the molecular mechanisms underlying loss of the BRCA1 function.
BRCA1 represses amphiregulin gene expression.
Treatment
View SamplesGene expression profiling of three PEL cell lines compare to three Burkitt's lymphoma lines to figure out the changed genes under KSHV latent infection.
The latency-associated nuclear antigen of Kaposi's sarcoma-associated herpesvirus modulates cellular gene expression and protects lymphoid cells from p16 INK4A-induced cell cycle arrest.
No sample metadata fields
View SamplesLuminal breast cancers express estrogen (ER) and progesterone (PR) receptors, and respond to endocrine therapies. However, some ER+PR+ tumors display intrinsic or acquired resistance, possibly related to PR. Two PR isoforms, PR-A and PR-B, regulate distinct gene subsets that may differentially influence tumor fate. A high PR-A:PR-B ratio is associated with poor prognosis and tamoxifen resistance. We speculate that excessive PR-A marks tumors that will relapse early. Here we address mechanisms by which PR-A regulate transcription, focusing on SUMOylation. We use receptor mutants and synthetic promoter/reporters to show that SUMOylation deficiency or the deSUMOylase SENP1 enhance transcription by PR-A, independent of the receptors dimerization interface or DNA binding domain. De-SUMOylation exposes the agonist properties of the antiprogestin RU486. Thus, on synthetic promoters, SUMOylation functions as an independent brake on transcription by PR-A. What about PR-A SUMOylation of endogenous human breast cancer genes? To study these, we used gene expression profiling. Surprisingly, PR-A SUMOylation influences progestin target genes differentially, with some upregulated, others downregulated, and others unaffected. Hormone-independent gene regulation is also PR-A SUMOylation dependent. Several SUMOylated genes were analyzed in clinical breast cancer database. In sum, we show that SUMOylation does not simply repress PR-A. Rather, it regulates PR-A activity in a target selective manner including genes associated with poor prognosis, shortened survival, and metastasis.
SUMOylation Regulates Transcription by the Progesterone Receptor A Isoform in a Target Gene Selective Manner.
Specimen part, Treatment
View SamplesGene expression was evaluated in 9 appendix samples removed from patients who went to the operating room with the diagnosis of acute appendicitis and 4 samples removed for non-inflammatory reasons.
Acute appendicitis is characterized by a uniform and highly selective pattern of inflammatory gene expression.
No sample metadata fields
View SamplesMalignant epithelia and tumor-associated stroma of PABC and Non-PABC were isolated by laser capture microdissection and gene expression profiled. Additionally, normal breast epithelia and stroma adjacent to the two tumor types were profiled.
Genomic signatures of pregnancy-associated breast cancer epithelia and stroma and their regulation by estrogens and progesterone.
Specimen part, Subject
View SamplesMenopausal estrogen (E2) replacement therapy increases the risk of estrogen receptor (ER)-positive epithelial ovarian cancers (EOC). Whether E2 is tumorigenic or promotes expansion of undiagnosed pre-existing disease is unknown. To determine E2 effects on tumor promotion, we developed an intraperitoneal mouse xenograft model using ZsGreen fluorescent ER- 2008 and ER+ PEO4 human EOC cells. Tumor growth was quantified by in vivo fluorescent imaging. In ER+ tumors, E2 significantly increased size, induced progesterone receptors, and promoted lymph node metastasis, confirming that ER are functional and foster aggressiveness. Laser captured human EOC cells from ER- and ER+ xenografted tumors were profiled for expression of E2-regulated genes. Three classes of E-regulated EOC genes were defined, but less than 10% were shared with E-regulated breast cancer genes. Since breast cancer selective ER modulators (SERM) are therapeutically ineffective in EOC, we suggest that our EOC-specific E-regulated genes can assist pharmacologic discovery of ovarian targeted SERM.
Tissue-specific pathways for estrogen regulation of ovarian cancer growth and metastasis.
Specimen part
View SamplesFamilial platelet disorder with predisposition to acute myeloid leukemia (FPD/AML) is an autosomal dominant disease of the hematopoietic system, which is caused by heterozygous mutations in RUNX1. FPD/AML patients have a bleeding disorder characterized by thrombocytopenia with reduced platelet numbers and functions, and a tendency to develop AML. Currently no suitable animal models exist for FPD/AML as Runx1+/- mice and zebrafish do not develop bleeding disorders or leukemia. Here we derived induced pluripotent stem cells (iPSCs) from two patients in a family with FPD/AML, and found that the FPD iPSCs display defects in megakaryocytic differentiation in vitro. We corrected the RUNX1 mutation in one FPD iPSC line through gene targeting, which led to normalization of megakaryopoiesis of the iPSCs in culture. Our results demonstrate successful in vitro modeling of FPD with patient-specific iPSCs and confirm that RUNX1 mutations are responsible for megakaryopoietic defects in FPD patients.
Targeted correction of RUNX1 mutation in FPD patient-specific induced pluripotent stem cells rescues megakaryopoietic defects.
No sample metadata fields
View SamplesInappropriate activation of developmental pathways is a well-recognized tumor-promoting mechanism. Here we show that overexpression of the homeoprotein Six1, normally a developmentally restricted transcriptional regulator, increases Transforming Growth Factor-beta (TGF-beta) signaling in mammary carcinoma cells and induces an epithelial to mesenchymal transition (EMT) that is in part dependent on its ability to increase TGF-beta signaling. TGF-beta signaling and EMT have been implicated in metastatic dissemination of carcinoma. Using spontaneous and experimental metastasis mouse models, we demonstrate that Six1 overexpression promotes breast cancer metastasis. In addition, we show that, like its induction of EMT, Six1-induced experimental metastasis is dependent on its ability to activate TGF-beta signaling. Importantly, in human breast cancers Six1 significantly correlates with nuclear Smad3, and thus increased TGF-beta signaling. Further, breast cancer patients whose tumors overexpress Six1 have a shortened time to relapse and metastasis, and an overall decrease in survival. Finally, we show that the effects of Six1 on tumor progression likely extend beyond breast cancer, since its overexpression correlates with adverse outcomes in numerous other cancers, including brain, cervical, prostate, colon, kidney, and liver, amongst others. Our findings argue that Six1, acting through TGF-beta signaling and EMT, is a powerful and global promoter of cancer metastasis.
The Six1 homeoprotein induces human mammary carcinoma cells to undergo epithelial-mesenchymal transition and metastasis in mice through increasing TGF-beta signaling.
Cell line
View SamplesBone marrow-derived macrophages were produced from mice lacking IL-10 alone (IL10-def) or mice lacking both IL-10 and the p50/p105 subunit of NF-kB (p50/IL10), and left unstimulated, stimulated with LPS (1 ng/ml) or stimulated with LPS and IL-10 (0.3 ng/ml).
NF-κB1 inhibits TLR-induced IFN-β production in macrophages through TPL-2-dependent ERK activation.
Specimen part
View SamplesCutaneous T-cell lymphoma (CTCL) develops from clonally expanded CD4+ T cells in a background of chronic inflammation. Dendritic cells (DCs) are potent T-cell stimulators; yet despite DCs' extensive presence in skin, cutaneous T cells in CTCL do not respond with effective anti-tumor immunity. We evaluated primary T-cell and DC émigrés from epidermal and dermal explant cultures of skin biopsies from CTCL patients (n = 37) and healthy donors (n = 5). Compared with healthy skin, CD4+ CTCL populations contained more T cells expressing PD-1, CTLA-4, and LAG-3; and CD8+ CTCL populations comprised more T cells expressing CTLA-4 and LAG-3. CTCL populations also contained more T cells expressing the inducible T-cell costimulator (ICOS), a marker of T-cell activation. DC émigrés from healthy or CTCL skin biopsies expressed PD-L1, indicating that maturation during migration resulted in PD-L1 expression irrespective of disease. Most T cells did not express PD-L1. Using skin samples from 49 additional CTCL patients for an unsupervised analysis of genome-wide mRNA expression profiles corroborated that advanced T3/T4 stage samples expressed higher levels of checkpoint inhibition genes compared with T1/T2 stage patients or healthy controls. Exhaustion of activated T cells is therefore a hallmark of both CD4+ and CD8+ T cells directly isolated from the lesional skin of patients with CTCL, with a continuum of increasing expression in more advanced stages of disease. These results justify identification of antigens driving T-cell exhaustion and the evaluation of immune checkpoint inhibition to reverse T-cell exhaustion earlier in the treatment of CTCL. Overall design: RNA-seq correlated with tumor stages
Primary T Cells from Cutaneous T-cell Lymphoma Skin Explants Display an Exhausted Immune Checkpoint Profile.
Specimen part, Disease, Disease stage, Subject
View Samples