Project description:We report the transcriptional difference of LATS1/2 gene knock out T47D cells with wild type control using RNA-seq technology. We further generated the chromatin binding of multiple proteins, including YAP, TEAD2, Estrogen receptor alpha, VGLL3 and several histone marks, as well as ATAC profiling between LATS1/2 gene knock out MCF7 cells with wild type control.
Project description:Estrogen receptor (ER) signaling–dependent cancer cell growth is one of the major features of ER-positive breast cancer (BC). Inhibition of ER function is a standard and effective treatment for ER-positive tumors; however, ~20% of patients with ER-positive BC experience early or late recurrence. In this study, we examined intertumor heterogeneity from an epigenetic perspective based on the hypothesis that the intrinsic difference in epigenetic states around ER signaling pathway underlies endocrine therapy resistance. We profiled chromatin accessibility data from 42 BC samples, including 35 ER-positive human epidermal growth factor receptor 2 (HER2)-negative and 7 triple-negative tumors, identifying a subgroup of ER-positive BCs with a distinctive chromatin accessibility pattern including reduced accessibility to ER-responsive elements (EREs). The same subgroup was also observed in The Cancer Genome Atlas BC cohort. Despite the reduced accessibility to EREs, the expression of ER and potential ER target genes were not decreased in these tumors. Our findings highlight the existence of a subset of ER-positive BCs with unchanged ER expression but reduced EREs accessibility that cannot be distinguished by conventional immunostaining for ER. Future studies should determine whether these tumors are associated with resistance to endocrine therapy.
Project description:RanBP2 type and C3HC4 type zinc finger containing protein 1 (RBCK1,) is a 58 kDa protein containing N-terminal ubiquitin like (UBL) domain, npl4 type zinc finger (NZF) domain and catalytic carbon terminal RBR domain. It is known that it has abnormal expression in tumors, making it a valuable diagnostic marker and drug target. A large number of studies have confirmed that in ER positive breast cancer, about 25%-40% of the tumor showed a visible hypoxia area. Under hypoxia, tumor cells can activate HIF1 pathway and widely activate the expression of downstream genes. Hypoxia inducible factor HIF-1 is composed of HIF-1α and HIF-1β Two subunits, The protein level of HIF-1α is precisely regulated by oxygen concentration. Here, we report RBCK1, a RING family ubiquitin ligase that regulates HIF1α, promoting ER positive breast cancer growth and inhibiting apoptosis. Deletion of RBCK1 inhibits ER positive breast cancer growth and promotes cell death. RNA sequencing analysis showed that in ER positive breast cancer, RBCK1 may be an important modifier of HIF1α signal pathway. Further experiments showed that RBCK1 and HIF1α Interacts and inhibits HIF1α polyubiquitination to inhibit HIF1α degradation in ER positive breast cancer cells. These finding reveals a novel direct HIF1α regulator and a potential therapeutic target for ER positive breast cancer.
Project description:The Hippo pathway, which is conserved from Drosophila to mammals, has been recognized as a tumor suppressor signaling pathway governing cell proliferation and apoptosis, two key events involved in organ size control and tumorigenesis. Although several upstream regulators, the conserved kinase cascade and key downstream effectors including nuclear transcriptional factors have been defined, the global organization of this signaling pathway is not been fully understood. Thus, we conducted a proteomic analysis of human Hippo pathway, which revealed the involvement of an extensive protein-protein interaction network in this pathway. Our data suggest that 550 interactions within 343 unique protein components constitute the central protein-protein interaction landscape of human Hippo pathway. Our study provides a glimpse into the global organization of Hippo pathway, reveals previously unknown interactions within this pathway, and uncovers new potential components involved in the regulation of this pathway. Understanding these interactions will help us further dissect the Hippo signaling-pathway and extend our knowledge of organ size control. Mass spectrometry data anaylsis: Excised gel bands were cut into approximately 1 mm3 pieces. Gel pieces were then subjected to in-gel trypsin digestion and dried. Samples were reconstituted in 5 ul of HPLC solvent A (2.5% acetonitrile, 0.1% formic acid). A nano-scale reverse-phase HPLC capillary column was created by packing 5 um C18 spherical silica beads into a fused silica capillary (100 um inner diameter x 20 cm length) with a flame-drawn tip. After equilibrating the column each sample was loaded via a Famos autosampler (LC Packings, San Francisco CA) onto the column. A gradient was formed and peptides were eluted with increasing concentrations of solvent B (97.5% acetonitrile, 0.1% formic acid). As peptides eluted they were subjected to electrospray ionization and then entered into an LTQ Velos ion-trap mass spectrometer (ThermoFisher, San Jose, CA). Peptides were detected, isolated, and fragmented to produce a tandem mass spectrum of specific fragment ions for each peptide. Peptide sequences (and hence protein identity) were determined by matching protein databases with the acquired fragmentation pattern by the software program, SEQUEST (ver. 28). (ThermoFisher, San Jose, CA). Enzyme specificity was set to partially tryptic with 2 missed cleavages. Modifications included carboxyamidomethyl (cysteines, fixed) and oxidation (methionine, variable). Mass tolerance was set to 2.0 for precursor ions and 1.0 for fragment ions. The database searched was the Human IPI databases version 3.6. Because we used HEK293 cells the Human IPI database was used. The number of entries in the database was 160,900 which included both the target (forward) and the decoy (reversed) human sequences. Spectral matches were filtered to contain less than 1% FDR at the peptide level based on the target-decoy method. Finally, only tryptic matches were reported and spectral matches were manually examined. When peptides matched to multiple proteins, the peptide was assigned so that only the most logical protein was included (Occam's razor). This same principle was used for isoforms when present in the database.
Project description:Adjuvant tamoxifen is a valid treatment option for women with estrogen receptor (ER)-positive breast cancer. However, up to 40% of patients experience distant or local recurrence or die. MicroRNAs have been suggested to be important prognosticators in breast cancer. This study aims to identify microRNAs with the potential to predict tamoxifen response. We performed a global microRNA screen in primary tumours of six matched pairs of postmenopausal, ER-positive breast cancer patients treated with tamoxifen, who were either recurrence free or had developed a recurrence. Patients were treated at the Robert Bosch Hospital, Stuttgart, Germany, between 1986 and 2005. Total RNA from FFPE tissue from 12 postmenopausal patients with ER-positive breast cancer (6 patients with and 6 patients without recurrence) was extracted. Hybridisation of biotin-labelled RNA was performed on Affymetrix GeneChip miRNA_2.0 Arrays.
Project description:Purpose: To perform RNA-Seq expression profiling from Young Women's Breast Cancer FFPE tissues, comparing ER+ Postpartum Brest Cancer to ER+ Nulliparous Breast Cancer Methods: RNA was extracted and isolated from archival Estrogen Receptor Positive primary breast cancer FFPE tissues ( 9 Postpartum, 7 Nulliparous). RNA species selected for inclusion in library utilzing Illumina-Access bead based oligo library preparation representing > 98% of known protein coding genes. Results: We identified gene pathway differences in estrogen receptor signaling, t-cell immunity and cell cycle between nulliparous and postpartum breast cancer cases. Subset analysis also revealed an enrichment in extra-cellular matrix pathway related genes in postpartum compared to nulliparous and luminal A cases.
Project description:Advanced breast cancer is characterised by enhanced tumour adaptability to therapeutic pressure and the metastatic microenvironment. Transcriptome differences in three ER positive (ER+) cell models are uncovered through this RNA-seq analysis of MCF7 (endocrine sensitive), LY2 (endocrine resistant) and T347 (derived from an ER-positive, treatment resistant brain metastatic patient tumour) cells.