We used microarrays to develop gene signatures for XBP1 and IRE1 in myeloma cells to explore the role of this UPR/differentiation pathway in proteasome inhibitor resistance.
Xbp1s-negative tumor B cells and pre-plasmablasts mediate therapeutic proteasome inhibitor resistance in multiple myeloma.
Specimen part, Cell line
View SamplesTumor metastasis and lack of NKG2D ligand (NKG2DL) expression are associated with poor prognosis in patients with colon cancer. Here we found that spironolactone (SPIR), an FDA-approved diuretic drug with a long-term safety profile, can upregulate NKG2DL expression in multiple colon cancer cell lines by activating the ATM-Chk2-mediated checkpoint pathway, which in turn enhances tumor elimination by natural killer cells. SPIR can also upregulate the expression of metastasis-suppressor genes TIMP2 and TIMP3, thereby reducing tumor cell invasiveness. Although SPIR is an aldosterone antagonist, its anti-tumor effects are independent of the mineralocorticoid receptor pathway. Instead, by screening the human nuclear hormone receptor siRNA library, we identify retinoid X receptor gamma (RXR gamma) as being indispensable for the anti-tumor functions of SPIR. Collectively, our results strongly support the use of SPIR or other RXR gamma-agonists with minimal side effects for colon cancer prevention and therapy.
Modulation of NKG2D ligand expression and metastasis in tumors by spironolactone via RXRγ activation.
Treatment
View SamplesWe have employed whole genome microarray expression profiling to identify genes differentially expressed in cord blood purified neutrophils after a short-term exposure to peptidoglycan (PGN).
Expression profile of cord blood neutrophils and dysregulation of HSPA1A and OLR1 upon challenge by bacterial peptidoglycan.
Specimen part, Treatment
View SamplesThymocyte selection-associated high mobility group box protein family member 2 (TOX2) is a transcription factor belonging to the TOX family that shares a highly conserved high mobility group DNA binding domain with the other TOX members. While TOX1 has been shown to be an essential regulator of T-cell and natural killer (NK) cell differentiation in mice, little is known about the roles of the other TOX family members in lymphocyte development, particularly in humans. In this study, we found that TOX2 was preferentially expressed in mature human NK cells and was upregulated during in vitro differentiation of NK cells from human umbilical cord blood (UCB)derived CD34+ cells. Gene silencing of TOX2 intrinsically hindered the transition between early developmental stages of NK cells, while overexpression of TOX2 enhanced the development of mature NK cells from UCB CD34+ cells. We subsequently found that TOX2 was independent of ETS-1 but could directly upregulate the transcription of TBX21 (encoding T-BET). Overexpression of T-BET rescued the TOX2 knockdown phenotypes. Given the essential function of T-BET in NK cell differentiation, TOX2 therefore plays a crucial role in controlling normal NK cell development by acting upstream of TBX21 transcriptional regulation.
TOX2 regulates human natural killer cell development by controlling T-BET expression.
Specimen part, Subject
View SamplesEye development and photoreceptor maintenance requires the retinal pigment epithelium (RPE), a thin layer of cells that underlies the neural retina. Despite its importance, RPE development has not been studied by a genomic approach. A microarray expression profiling methodology was established in this study for studying RPE development. The intact retina with RPE attached was dissected from developing embryos, and differentially expressed genes in RPE were inferred by comparing the dissected tissues with retinas without RPE using microarray and statistical analyses. We found 8810 probesets to be significantly expressed in RPE at 52 hours post-fertilization (hpf), of which 1443 might have biologically meaningful expression levels. Further, 78 and 988 probesets were found to be significantly over- or under-expressed in RPE respectively compared to retina. Also, 79.2% (38/48) of the known over-expressed probesets have been independently validated as RPE-related transcripts. The results strongly suggest that this methodology can obtain in vivo RPE specific gene expression from the zebrafish embryos and identify novel RPE markers.
Gene expression profiling of zebrafish embryonic retinal pigment epithelium in vivo.
Specimen part
View SamplesRetinal cells are specified in a zebrafish recessive mutant called young (yng) but they fail to terminally differentiate; i.e. extend neurites and make synaptic contacts. A point mutation in a brahma-related gene 1 (brg1) is responsible for this phenotype. In this microarray study, a three-factor factorial design was utilized to investigate the effects of 1) mutation, 2) change in time (36 vs. 52hpf), and 3) change in tissue (retina vs. whole embryos), and their interactions on gene expression. Significant probesets were inferred by using both specific contrasts of the fitted Analysis of Variance (ANOVA) models and a corresponding 2-fold expression cutoff. The probesets were grouped into three broad categories: 1) Brg1-regulated retinal differentiation genes (731 probsets), 2) Retinal specific genes but independent of Brg1 regulation (3038 probesets) and 3) Genes regulated by Brg1 but outside the retina (107 probesets). Four gene groups/pathways including neurite outgrowth regulators, Delta-Notch signalling molecules, Irx family members and specific cell cycle regulators were identified in the first group, and their relevance for retinal differentiation functionally validated. This study demonstrates that an approach such as ours can identify relevant genes and pathways involved in retinal development as well as the development of other tissues at the same time.
Factorial microarray analysis of zebrafish retinal development.
Specimen part
View SamplesWe used microarrays to compare gene expression profiles between mouse mammary tumors initiated by Myc to those that have escaped Myc oncogene dependence.
Heterogeneity in MYC-induced mammary tumors contributes to escape from oncogene dependence.
Specimen part
View SamplesTo examine the differences between bone marrow (BM) and peripheral blood (PB) myeloblasts in acute myeloid leukaemia (AML), we compared CD34+ myeloblasts of paired BM and peripheral blood (PB) samples from AML patients using microarray.
A comparative study of bone marrow and peripheral blood CD34+ myeloblasts in acute myeloid leukaemia.
No sample metadata fields
View SamplesWe have used the slow cycling property, found in hair follicle stem cells, to look for LRCs in sweat glands as putative stem cells.
Label retaining cells (LRCs) with myoepithelial characteristic from the proximal acinar region define stem cells in the sweat gland.
Specimen part
View SamplesPurpose: The purpose of this study was to develop a framework for analyzing RPE expression profiles from zebrafish eye mutants. Methods: The fish model we used was smarca4 (SWI/SNF related, matrix associated, actin dependent regulator of chromatin, subfamily a, member 4), a retinal dystrophic mutant that the retinal phenotype and expression profiles were previously characterized. Histological and Affymetrix GeneChip analyses were conducted to define the RPE defects and underlying differential expression respectively. Results: Histological analysis indicates that smarca4 RPE was formed but its differentiation was abnormal. In particular, ultra-structural analysis of smarca4 RPE by transmission electron microscopy showed a number of defects in melanogenesis, suggesting that the cytoskeletal dynamics was impaired. To compare the expression profile of normal wild-type (WT) and smarca4 RPE, their retinas and RPE-attached retinas were microdissected and the gene expression values of these tissues measured by Affymetrix GeneChip analysis. The RPE expression values were then estimated from these samples using an approach previously established by us. A factorial analysis was conducted using the expression values of RPE, retinal as well as the whole-embryo samples. Specific rules (contrasts) were built using the coefficients of the resulting fitted model to select for three groups of genes: 1) Smarca4-regulated RPE genes, 2) Smarca4-regulated retinal genes, and 3) Smarca4-regulated RPE genes that are not differentially expressed in the retina. The latter group consists of 39 genes that are highly related to cytoskeletal dynamics, melanogenesis, paracrine and intracellular signal transduction. Conclusions: Our analytical framework can potentially identify genes in zebrafish mutants that both retina and RPE are affected by the underlying mutation.
Expression profiling of the RPE in zebrafish smarca4 mutant revealed altered signals that potentially affect RPE and retinal differentiation.
Specimen part
View Samples