Project description:MCF7 cells were infected with lentiviral particles containing LIFR-targeted shRNAs then chemically selected to create a stable pooled population of shLIFR MCF7 cells. The goal of the study was to determine the downstream targets of LIFR in human MCF7 breast cancer cells.
Project description:We performed RNA-seq to observe the gene expression changes in cells following siRNA-mediated knockdown of DDX3X and DDX54 RNA helicases in human breast cancer MCF7 cells. Two siRNAs were used to target each RNA helicase and scramble siRNA-treated MCF7 cells were used as controls.
Project description:Dlx3 over-expression in mouse embryonic fibroblasts changed the expression level of numerous genes involved in osteogenesis and embryonic stem cell-related pathways as revealed by microarray analysis. From the list of Dlx3 modulated genes we focused our attention on the study of two candidates, Lifr and Chrdl1. Chromatin immunoprecipitation demonstrated the recruitment of Dlx3 transcription factor to the promoters of Lifr and Chrdl1, and luciferase assays confirmed the role of Dlx3 in the regulation of Lifr expression. Over-expression of Dlx3 in mouse embryonic stem cells stimulated Lifr and Chrdl1 expression and inhibited expression of Id proteins and Bmp4. We show that Dlx3 increases the expression of both soluble and transmembrane forms of Lifr. Soluble Lifr may regulate extracellular Lif levels via solution binding, while transmembrane Lifr mediates the signal transduction pathway. The data suggests that Dlx3 may be involved in stem cell differentiation in a dosage dependent way through its interaction with Lifr and with Chrdl1, a known antagonist of Bmp4. We speculate that Dlx3 may also be involved in osteoblast differentiation through interactions involving Lifr, Bmp, and Id proteins and signaling via the JAK/STAT and MAPK pathways. In summary, our data suggests that Dlx3 proteins play a significant role in a highly tuned network in early embryogenesis. Keywords: treated vs.untreated Stable and Transient transfection of Dlx3 in MEF. Total of 4 hybridizations including biological replicates.
Project description:The poly(rC) binding protein 1 gene (PCBP1) encodes the heterogenous nuclear ribonucleoprotein E1 (hnRNPE1), a nucleic acid binding protein that plays a tumor-suppressive role in mammary epithelium by regulating phenotypic plasticity and cell fate. Following loss of PCBP1 function, the FAM3C gene (encoding the Interleukin-like EMT inducer, or “ILEI” protein) and the leukemia inhibitory factor receptor (LIFR) gene are upregulated. Interaction between FAM3C and LIFR in the extracellular space induces phosphorylation of the signal transducer and activator of transcription 3 (pSTAT3). The overexpression and/or hyperactivity of STAT3 has been detected in 40% of breast cancer cases and is associated with poor prognosis. Herein, we characterize feed-forward regulation of LIFR expression in response to FAM3C/LIFR/pSTAT3 signaling in mammary epithelial cells, and show that PCBP1 upregulates LIFR transcription through FAM3C, involving activity at the LIFR promoter. Additionally, our bioinformatic analysis reveals a signature of transcriptional regulation associated with FAM3C/LIFR interaction and identifies the TWIST1 transcription factor as a downstream effector that participates in maintenance of LIFR expression. Finally, we characterize the effect of LIFR expression in cell-based experiments that demonstrate promotion of invasion, migration, and breast cancer stem cell (BCSC) self-renewal, consistent with previous studies that link LIFR expression to tumor initiation and metastasis in mammary epithelial cells.
