Accumulating data indicate translation plays a role in cancer biology, particularly its rate limiting stage of initiation. Despite this evolving recognition, the function and importance of specific translation initiation factors is unresolved. The eukaryotic translation initiation complex eIF4F consists of eIF4E and eIF4G at a 1:1 ratio. Although it is expected that they display interdependent functions, several publications suggest independent mechanisms. This study is the first to directly assess the relative contribution of eIF4F components to the expressed cellular proteome, transcription factors, microRNAs, and phenotype in a malignancy known for extensive protein synthesis- multiple myeloma (MM). Previously, we have shown that eIF4E/eIF4GI attenuation (siRNA/ Avastin) deleteriously affected MM cells' fate and reduced levels of eIF4E/eIF4GI established targets. Here, we demonstrated that eIF4E/eIF4GI indeed have individual influences on cell proteome. We used an objective, high throughput assay of mRNA microarrays to examine the significance of eIF4E/eIF4GI silencing to several cellular facets such as transcription factors, microRNAs and phenotype. We showed different imprints for eIF4E and eIF4GI in all assayed aspects. These results promote our understanding of the relative contribution and importance of eIF4E and eIF4GI to the malignant phenotype and shed light on their function in eIF4F translation initiation complex.
eIF4E and eIF4GI have distinct and differential imprints on multiple myeloma's proteome and signaling.
Specimen part, Cell line, Treatment
View SamplesThe placenta is a nonsupportive microenvironment for cancer cells. We showed that breast cancer cells (BCCL) were eliminated from placental implantation sites. During implantation, the placenta manipulates its surrounding matrix, which may induce BCCL elimination. Here, we explored the effect of placenta-induced ECM manipulations on BCCL. During experiments, BCCL (MCF-7/T47D) were cultured on placenta/BCCL-conditioned ECM (Matrigel used for first trimester placenta/BCCL culture and cleared by NH4OH). After culturing the cells, we analyzed cancer cell phenotype (death, count, aggregation, MMP) and signaling (microarray analysis and pathway validation). We found that the BCCL did not attach to previous placental implantation sites and instead, similarly to anoikis-resistant cells, migrated away, displayed increased MMP levels/activity, and formed aggregates in distant areas. T47D were less affected than the MCF-7 cells, since MCF-7 also showed modest increases in cell death, EMT, and increased proliferation. Microarray analysis of the MCF-7 highlighted changes in the integrin, estrogen, EGFR, and TGFb pathways. Indeed, placental ECM reduced ERa, induced Smad3/JNK phosphorylation and increased integrin-a5 expression (RGD-dependent integrin) in the BCCL. Addition of RGD or TGFbR/JNK inhibitors reversed the phenotypic changes. This study helps explain the absence of metastases to the placenta and why advanced cancer is found in pregnancy, and provides possible therapeutic targets for anoikis-resistant cells.
First trimester human placenta prevents breast cancer cell attachment to the matrix: The role of extracellular matrix.
Specimen part, Treatment
View SamplesThe recently proposed exozyme hypothesis posits that subunits of the RNA processing exosome assemble into structurally distinct protein complexes that function in disparate cellular compartments and RNA metabolic pathways. Here, in a genetic test of this hypothesis, we examine the role of Dis3 -- an essential polypeptide with endo- and 3'' to 5'' exo-ribonuclease activity -- in cell cycle progression. We present several lines of evidence that perturbation of DIS3 affects microtubule (MT) localization and structure in Saccharomyces cerevisiae. Cells with a DIS3 mutation: (i) accumulate anaphase and pre-anaphase mitotic spindles; (ii) exhibit spindles that are mis-oriented and displaced from the bud neck; (iii) harbor elongated spindle-associated astral MTs; (iv) have an increased G1 astral MT length and number; and (v) are hypersensitive to MT poisons. Mutations in the core exosome genes RRP4 and MTR3 and the exosome cofactor gene MTR4 -- but not other exosome subunit gene mutants -- also elicit MT phenotypes. RNA deep sequencing analysis (RNA-seq) shows broad changes in the levels of cell cycle- and microtubule-related transcripts in mutant strains. Collectively, the different mitotic phenotypes and distinct sets of mRNAs affected by the exosome subunit and cofactor mutants studied here suggest that Dis3 has a core exosome-independent role(s) in cell cycle progression. These observations are consistent with the predictions of the exozyme hypothesis and also suggest an evolutionarily conserved role for Dis3 in linking RNA metabolism, MTs, and mitotic progression. Overall design: RNA-seq analysis of total RNA harvested from WT, mtr3-1, mtr4-1, and Dis3^mtr (rrp44-1/mtr17-1) Saccharomyces cerevisiae strains after a temperature shift.
Pronounced and extensive microtubule defects in a Saccharomyces cerevisiae DIS3 mutant.
Cell line, Treatment, Subject
View SamplesFunctional discrimination between normal centroblast and centrocyte obtained from human inflamed tonsils after cell sorting.
CXCR4 expression functionally discriminates centroblasts versus centrocytes within human germinal center B cells.
Specimen part
View SamplesTo explore events that govern the differentiation of human nave B cells (NBCs) into memory B cells and plasma cells (PCs), we designed an in vitro 2-step culture model leading non-switched NBC precursors to differentiate into two cell compartments: CD20loCD38hi and CD20+CD38+.
IL-2 requirement for human plasma cell generation: coupling differentiation and proliferation by enhancing MAPK-ERK signaling.
Specimen part, Subject, Time
View SamplesGEP on Affymetrix Genechip HTA 2.0 microarrays was performed on ex vivo cell-sorted GC-Tfh and pre-Tfh from TONS and FL
Human Lymphoid Stromal Cells Contribute to Polarization of Follicular T Cells Into IL-4 Secreting Cells.
Specimen part, Treatment
View SamplesGEP on Affymetrix U133+2.0 microarrays was performed on in vitro expanded stromal cells
Human Lymphoid Stromal Cells Contribute to Polarization of Follicular T Cells Into IL-4 Secreting Cells.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
BIM upregulation and ROS-dependent necroptosis mediate the antitumor effects of the HDACi Givinostat and Sorafenib in Hodgkin lymphoma cell line xenografts.
Specimen part, Cell line, Treatment
View SamplesTumor infiltrating neutrophils (TAN) have been shown to exert both pro- and anti-tumoral activities and their recruitment and polarization are triggered by tumor-derived signals. Resident mesenchymal stromal cells (MSC) could contribute to tumor-supportive cell niche and have been shown to display tumor-specific transcriptomic, phenotypic, and functional features compared to normal tissue. In our study, we investigate whether these two cell subsets establish a bidirectional crosstalk in the context of B-cell lymphoma.
Neutrophils trigger a NF-κB dependent polarization of tumor-supportive stromal cells in germinal center B-cell lymphomas.
Treatment
View SamplesRelapsed/refractory Hodgkin lymphoma (HL) is an unmet medical need requiring new therapeutic options. Interactions between the histone deacetylase inhibitor Givinostat and the RAF/MEK/ERK inhibitor Sorafenib were examined in HDLM-2 and L-540 HL cell lines. Exposure to Givinostat/Sorafenib induced a synergistic inhibition of cell growth (range, 70- 80%) and a dramatic increase in cell death (up to 96%) due to increased H3 and H4 acetylation and strong mitochondrial injury. Gene expression profiling indicated that the synergistic effects of Givinostat/Sorafenib treatment are associated with the modulation of cell cycle and cell death pathways. Exposure to Givinostat/Sorafenib resulted in sustained production of reactive oxygen species (ROS) and activation of necroptotic cell death. The necroptosis inhibitor Necrostatin-1 prevented Givinostat/Sorafenib-induced ROS production, mitochondrial injury, activation of BH3-only protein BIM and cell death. Knockdown experiments identified BIM as a key signaling molecule that mediates Givinostat/Sorafenib-induced oxidative death of HL cells. Furthermore, in vivo xenograft studies demonstrated a 50% reduction in tumor burden (P < 0.0001), a 5- to 15-fold increase in BIM expression (P .0001) and a 4-fold increase in tumor necrosis in Givinostat/Sorafenib-treated animals compared to mice that received the single agents. These results provide a rationale for exploring Givinostat/Sorafenib combination in relapsed/refractory HL.
BIM upregulation and ROS-dependent necroptosis mediate the antitumor effects of the HDACi Givinostat and Sorafenib in Hodgkin lymphoma cell line xenografts.
Cell line, Treatment
View Samples