The yeast PMR1 (ATP2C1) gene codes for the eukaryotic prototype of a high affinity P-type ATPase required for Ca2+/Mn2+ transport into the Golgi. Cells lacking PMR1 exhibit multiple genetic interactions with genes involved in DNA recombination and replication, a fact that is not yet understood. We find that deletion of PMR1 causes a delay in DNA replication initiation, progression and G2/M transition and induces the transcriptional up-regulation of genes involved in cell cycle regulation, including CLB5 and SWE1. Interestingly, pmr1 clb5 double mutants exhibit a dramatic delay in DNA replication and increased DNA breakage, while endoreplication and the formation of multi-nucleated, giant yeast is observed in pmr1 swe1 cells. Because these phenotypes can be attributed to impeded Mn2+-pump function, we provide a model in which Mn2+ interferes with Mg2+ in the nucleus, and vice versa, Mg2+ interferes with Mn2+ in the Golgi. Consequently, cell cycle progression is challenged by aberrant catalytic activities of enzymes involved in replication and protein glycosylation.
Impaired manganese metabolism causes mitotic misregulation.
No sample metadata fields
View SamplesMultiple myeloma (MM) cells were treated with the BET inhibitor CPI203 alone and in combination with lenalidomide plus dexamethasone in vitro and in vivo (mouse xenograft).
The BET bromodomain inhibitor CPI203 improves lenalidomide and dexamethasone activity in <i>in vitro</i> and <i>in vivo</i> models of multiple myeloma by blockade of Ikaros and MYC signaling.
Specimen part, Cell line, Treatment
View SamplesMechanisms of immune regulation may control proliferation of aberrant plasma cells (PCs) in patients with the asymptomatic monoclonal gammopathy of undetermined significance (MGUS) preventing progression to active multiple myeloma (MM). We investigated the role of CD85j (LILRB1), an inhibitory immune checkpoint for B cell function, in MM pathogenesis.
Loss of the Immune Checkpoint CD85j/LILRB1 on Malignant Plasma Cells Contributes to Immune Escape in Multiple Myeloma.
Specimen part, Cell line
View SamplesMalignant progression in cancer has been associated with the emergence of populations of tumor-initiating cells (TIC) endowed with capabilities for unlimited self-renewal, survival under stress and establishment of distant metastases. Additionally, the acquisition of invasive properties driven by the genetic program known as epithelialmesenchymal transition (EMT) may be an essential step in the evolution of neoplastic cells into fully metastatic populations. A widely accepted paradigm is that EMT potentiates tumor cell self-renewal and metastatic behaviour. Here we describe a cellular model in which a clonal population enriched in TIC expresses a genetic program distinct from a second population with traits of stable EMT, and in which both populations cooperate for enhanced local invasiveness and metastasis. Induction of the TIC-enriched population to undergo EMT by several stimuli or by constitutive overexpression of the transcription factor SNAI1 engaged a mesenchymal program while suppressing the CSC program. This suggests that TIC and EMT, contrary to current paradigms, correspond to alternative states. Furthermore, diffusible factors secreted by the population with EMT traits also induced mesenchymal reprogramming of the population enriched in CSCs. Local invasiveness in vitro and lung colonization in vivo of the TIC-enriched population was enhanced by co-injection with the EMT-trait population, and expanded the range of organs to which it metastasized. Thus, in our model, relatively stable TIC and EMT phenotypes reflect alternative genetic programs expressed by distinct clonal populations. We also suggest that dynamic cooperation between tumor subpopulations displaying either TIC or EMT traits may be a general mechanism driving local invasiveness and metastasis.
Epithelial-mesenchymal transition can suppress major attributes of human epithelial tumor-initiating cells.
Cell line
View SamplesWe sequenced mRNA from two preparations of isolated Notch-responsive ductal pancreas cells and compared transcript expression to all other non-Notch-responsive cells from each sample to charactarize zebrafish centroacinar cells. Overall design: Determination of gene expression levels in centroacinar cells and non-centroacinar cells from adult pancreas.
Centroacinar Cells Are Progenitors That Contribute to Endocrine Pancreas Regeneration.
No sample metadata fields
View SamplesThe tyrosine kinase ErbB2 positive breast tumors have more aggressive tumor growth, poorer clinical outcome, and more resistance to radiotherapy, chemotherapy and hormone therapy. A humanized anti-ErbB2 monoclonal antibody Herceptin and a small molecules inhibitor Lapatinib were developed and approved by FDA to treat patients with ErbB2 amplification and overexpression. Unfortunately, most ErbB2+ breast cancers do not respond to Herceptin and Lapatinib, and the majority of responders become resistant within 12 months of initial therapy (defined as secondary drug resistance). Such differences in response to Lapatinib treatment is contributed by substantial heterogeneity within ErbB2+ breast cancers. To address this possibility, we carried out transcriptomic analysis of mammary tumors from genetically diverse MMTV-ErbB2 mice. This will help us to have a better understanding of the heterogeneous response to ErbB2 targeted therapy and permit us to design better and more individualized (personalized) treatment strategies for human ErbB2 positive breast cancer.
Unraveling heterogeneous susceptibility and the evolution of breast cancer using a systems biology approach.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
The kinesin spindle protein inhibitor filanesib enhances the activity of pomalidomide and dexamethasone in multiple myeloma.
Specimen part, Cell line, Treatment
View SamplesKinesin spindle protein (KSP) inhibition is known to be an effective therapeutic approach in several malignancies. Filanesib (Arry-520), a KSP inhibitor, has demonstrated activity in heavily pretreated multiple myeloma (MM) patients. The aim of this work was to investigate the activity of filanesib in combination with an IMiDs plus dexamethasone backbone, and the mechanisms underlying the potential synergistic effect. Results: Filanesib showed in vitro and in vivo synergy with all IMiDs plus dexamethasone treatment, particularly with the pomalidomide combination (PDF). Importantly, the in vivo synergy observed in this combination was more evident in large, highly proliferative tumors, and it was shown to be mediated by impairment of mitosis transcriptional control, an increase in monopolar spindles, cell cycle arrest and the induction of apoptosis in cells in proliferative phases. In addition, PDF increased the activation of the proapoptotic protein Bax, which has been previously associated with sensitivity to filanesib, and could potentially be used as a predictive biomarker of response to this combination. Conclusions: Our results provide preclinical evidence for the potential benefit of the combination of filanesib with pomalidomide and dexamethasone and es-tablished the basis for a recently activated trial being conducted by the Spanish MM group investigating this combination in relapsed MM patients.
The kinesin spindle protein inhibitor filanesib enhances the activity of pomalidomide and dexamethasone in multiple myeloma.
Specimen part, Treatment
View SamplesKinesin spindle protein (KSP) inhibition is known to be an effective therapeutic approach in several malignancies. Filanesib (Arry-520), a KSP inhibitor, has demonstrated activity in heavily pretreated multiple myeloma (MM) patients. The aim of this work was to investigate the activity of filanesib in combination with an IMiDs plus dexamethasone backbone, and the mechanisms underlying the potential synergistic effect. Results: Filanesib showed in vitro and in vivo synergy with all IMiDs plus dexamethasone treatment, particularly with the pomalidomide combination (PDF). Importantly, the in vivo synergy observed in this combination was more evident in large, highly proliferative tumors, and it was shown to be mediated by impairment of mitosis transcriptional control, an increase in monopolar spindles, cell cycle arrest and the induction of apoptosis in cells in proliferative phases. In addition, PDF increased the activation of the proapoptotic protein Bax, which has been previously associated with sensitivity to filanesib, and could potentially be used as a predictive biomarker of response to this combination. Conclusions: Our results provide preclinical evidence for the potential benefit of the combination of filanesib with pomalidomide and dexamethasone and es-tablished the basis for a recently activated trial being conducted by the Spanish MM group investigating this combination in relapsed MM patients.
The kinesin spindle protein inhibitor filanesib enhances the activity of pomalidomide and dexamethasone in multiple myeloma.
Cell line, Treatment
View SamplesAmyotrophic lateral sclerosis (ALS) is caused by the progressive degeneration of motor neurons. Mutations in the Cu/Zn superoxide dismutase (SOD1) are found in about 20% of patients with familial ALS. Mutant SOD1 causes motor neuron death through an acquired toxic property. Although, molecular mechanism underlying this toxic gain-of-function remains unknown, evidence support the role of mutant SOD1 expression in non-neuronal cells in shaping motor neuron degeneration. We have previously found that in contrast to non-transgenic, SOD1G93A-expressing astrocytes induced apoptosis of co-cultured motor neurons. This prompted us to investigate whether the effect on motor neuron survival was related to a change in the gene expression profile. Through high-density oligonucletide microarrays we found changes in the expression of genes involved in transcription, signaling, cell proliferation, extracellular matrix construction, response to stress and steroid and lipid metabolism. Decorin, a small multifunctional proteoglycan, was the most up-regulated gene. Down-regulated genes included the insulin-like growth factor-1 receptor and the RNA binding protein ROD1. We also analyzed the expression of selected genes in purified motor neurons expressing SOD1G93A and in spinal cord of asymptomatic and early symptomatic ALS-rodent model.
Transcriptional profile of primary astrocytes expressing ALS-linked mutant SOD1.
No sample metadata fields
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