Project description:To explore the potential target lncRNAs of EZH2 in breast cancer cells, we determined the lncRNA expression profiles in MCF7-control and MCF7-EZH2 overexpressing cells using lncRNA Microarray.
Project description:Purpose: Increasing evidence suggests that epigenetic reprogramming contributes significantly to the development of endocrine therapy resistance in breast cancer. The goal of this work is to explore how the histone methyltransferase EZH2 interacts with ER signaling and drives the insensitiveness of breast cancer cells to the antagonistic effect of tamoxifen on ER activity. Therefore, we comprehensively analyzed the transcriptional program regulated by EZH2 in EZH2 overexpressed MCF-7 cells. Methods: MCF-7 cells between passage 142-144 were used for this assay. For mRNA-Seq, cells are infected with control empty vector (EV) or EZH2 expressing plasmid (EZH2) by lentivirus. Total RNA were extracted by TRIzol (Invitrogen) and libraries were constructed using Illumina TruSeq RNA Sample Prep Kit v2 (Cat.# RS-122-2001). Hiseq 3000 was used for sequencing.
Project description:Abundant evidence has illustrated that long non-coding RNA (lncRNA) plays a vital role in the regulation of tumor development and progression. Most lncRNA have been proven to have biological and clinical significance in acute myeloid leukemia (AML), but further studies remain to be needed. In this study, we investigated lncRNA NR-104098 in AML and its specific mechanism. The microarray analysis was performed on NB4 cells. Based on the related analysis results, we identified that lncRNA NR-104098 is a suppressor gene that is significantly upregulated in AML cells. lncRNA NR-104098 could inhibit proliferation and induce differentiation in AML cells in vitro, and also play main role in the mouse xenografts. Mechanically, it was confirmed that lncRNA NR-104098 may effectively inhibit EZH2 transcription by directly binding E2F1 and recruiting E2F1 to EZH2 promoter. In addition, ATPR can significantly increase the expression of lncRNA NR-104098, whereas knocking down NR104098 can inhibit the inhibitory effect of ATPR on the proliferation and induction differentiation of AML cells. Taken together, these results lead to a deeper insight into the mechanism of ATPR induces AML differentiation and inhibits proliferation by inhibiting EZH2 on transcriptional level.
Project description:Ell3 is a RNA polymerase II transcription elongation factor that is enriched in testis. The C-terminal domain of Ell3 shows strong similarities to that of Ell (eleven-nineteen lysine-rich leukemia gene), which acts as a negative regulator of p53 and regulates cell proliferation and survival. Recent studies in our laboratory showed that Ell3 induces the differentiation of mouse embryonic stem cells by protecting differentiating cells from apoptosis via the promotion of p53 degradation. In this study, we evaluated the function of Ell3 in breast cancer cell lines. MCF7 cell lines overexpressing Ell3 were used to examine cell proliferation and cancer stem cell properties. Ectopic expression of Ell3 in breast cancer cell lines induces proliferation and 5-FU resistance. In addition, Ell3 expression increases the cancer stem cell population, which is characterized by CD44 (+) or ALDH1 (+) cells. Mammosphere-forming potential and migration ability were also increased upon Ell3 expression in breast cancer cell lines. Through biochemical and molecular biological analyses, we showed that Ell3 regulates proliferation, cancer stem cell properties and drug resistance in breast cancer cell lines partly through the MEK-extracellular signal-regulated kinase signaling pathway. Murine xenograft experiments showed that Ell3 expression promotes tumorigenesis in vivo. The transcription elongation factor Ell3 induces chemosensitization of MCF7 cells to the chemotherapeutic agent cis-diamminedichloroplatinum (II) (CDDP) by stabilizing p53. Interestingly, Ell3 induced p53 stabilization in response to CDDP by promoting binding of p53 to NADH quinoneoxidoreductase 1 (NQO1), which is linked to an ubiquitin-independent degradation pathway, as well as by suppressing a MDM2 mediated ubiquitin-dependent degradation pathway. Furthermore, Ell3 enhanced interleukin-20 (IL-20) expression leading to the activation of the ERK1/2 signaling pathway. By analyzing the suppressive effects of IL-20 and ERK signaling in the Ell3 expressing MCF7 cells, we confirmed that the IL-20 mediated ERK1/2 signaling pathway is the main cause of p53 stabilization after CDDP exposure in MCF7 cells. Ell3-overexpressing breast cancer cell lines were established using the chromosomal integration of an Ell3 expression plasmid, which was constructed by cloning PCR-amplified Ell3 cDNA into pcDNA3.1 vectors (Invitrogen, Carlsbad, CA; https://www.lifetechnologies.com). Three independent Ell3 overexpressing cell lines were generated. The gene expression profiles of wild type MCF7 and Ell3 overexpressing cell line were compared using Affymetrix PrimeView arrays.
Project description:MCF7 cells were infected with retrovirus to overexpress wild-type and mutant miR-222 Measure miRNA expression level in MCF7 cells after overexpressing wild-type and mutant miR-222