Cancer metastasis is a fetal problem that claims life of over 90% of cancer patients. It is hypothesized that cancer stem cells (CSCs) mediate cancer metastasis and such cells are often resistant to chemotherapy. Studying BRCA1 associated cancers, we found that CSCs form fillopodia and protrusions enriching for active forms of ezrin/radixin/moesin proteins and they have a much higher potential to metastasize than non-CSCs. Microarray analysis indicated that many pathways related to cell adhesion, extracellular matrix and cytoskeleton were differentially regulated in CSCs. Although inhibition of cytoskeleton remodeling by cisplatin treatment retarded CSC motility and cancer metastasis, drug resistant cancers eventually emerge containing markedly increased number of CSCs. This event is at least partially attributed to the activation of PI3K/mTOR signaling, and can be significantly inhibited by the treatment of rapamycin. These results provide strong evidence that cytoskeletal rearrangement and PI3K/mTOR signaling play a distinct role in mediating CSC mobility and viability, and blocking of both pathways in CSCs synergistically inhibits primary and metastatic cancer growth in BRCA1 associated tumors.
Synergistic therapeutic effect of cisplatin and phosphatidylinositol 3-kinase (PI3K) inhibitors in cancer growth and metastasis of Brca1 mutant tumors.
Specimen part
View SamplesWe are investigating the transcriptional response of Anc1 deficient yeast under basal and MMS exposed conditions
Anc1, a protein associated with multiple transcription complexes, is involved in postreplication repair pathway in S. cerevisiae.
No sample metadata fields
View SamplesTo gain further insights into the role of the transcriptome deregulation in the transition from a normal plasma cell (NPC) to a clonal PC and from an indolent clonal PC to a malignant PC, we performed gene expression profiling in 20 patients with MGUS, 33 with high-risk SMM and 41 with MM. The analysis showed that 126 genes were differentially expressed in MGUS, SMM and MM as compared to NPC. Interestingly, 17 and 9 out of the 126 significant differentially expressed genes were small nucleolar RNA molecules (snoRNA) and zinc finger proteins. GADD45A was the most significant up-regulated gene in clonal PC compared to NPC. Several proapoptotic genes (AKT1 and AKT2) were downregulated and antiapoptotic genes (APAF1 and BCL2L1) were upregulated in MM, both symptomatic and asymptomatic, compared to MGUS. Myc mediated apoptosis signaling is one of the top canonical pathways differentiating the asymptomatic and symptomatic myeloma. When we looked for those genes progressively modulated through the evolving stages of monoclonal gammopathies, eight snoRNA showed a progressive increase while APAF1, VCAN and MEGF9 exhibited a progressive downregulation in the transition from MGUS to SMM and to MM. In conclusion, our data show that although MGUS, SMM and MM are not clearly distinguishable groups according to their GEP, several signaling pathways and genes were significant deregulated in the different steps of transformation process.
Transcriptome analysis reveals molecular profiles associated with evolving steps of monoclonal gammopathies.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Phenotypic, transcriptomic, and genomic features of clonal plasma cells in light-chain amyloidosis.
Specimen part, Disease
View SamplesImmunoglobulin light-chain amyloidosis (AL) is a rare clonal plasma cell (PC) disorder that remains largely incurable. AL and multiple myeloma (MM) share the same cellular origin, but while knowledge about MM PC biology has improved significantly, the same does not apply for AL. Here, we undertook an integrative phenotypic, molecular, and genomic approach to study clonal PCs from 22 newly-diagnosed AL patients. Through principal-component-analysis, we demonstrated highly overlapping phenotypic profiles between AL and MGUS or MM patients. However, in contrast to MM, highly-purified FACSs-sorted clonal PCs in AL (n=9/22) show virtually normal transcriptomes with only 68 deregulated genes as compared to normal PCs, including a few tumor suppressor (CDH1, RCAN) and pro-apoptotic (GLIPR1, FAS) genes. Notwithstanding, clonal PCs in AL (n=11/22) were genomically unstable with a median of 9 copy-number-abnormities (CNAs) per case; many of which similar to those found in MM. Whole-exome sequencing (WES) was performed in three AL patients and revealed a median of 10 non-recurrent mutations per case. Altogether, we showed that although clonal PCs in AL display phenotypic and CNA profiles similar to MM, their transcriptome is remarkably similar to that of normal PCs. First-ever WES revealed the lack of a unifying mutation in AL
Phenotypic, transcriptomic, and genomic features of clonal plasma cells in light-chain amyloidosis.
Specimen part, Disease
View SamplesWe used next generation sequencing to analyze the gene expression changes in U2OS osteosarcoma cells expressing shRNA targeting the promyelocytic leukemia (PML) gene transcripts Overall design: cDNA libraries of U2OS cells expressing control shRNA or shRNA targeting PML were generated from one biological replicate
PML nuclear bodies contribute to the basal expression of the mTOR inhibitor DDIT4.
No sample metadata fields
View SamplesTo determine if aberrant activation of endothelin-1 (Et1) could lead to the dysregulation of many downstream genes, we exposed fibroblasts to exogenous ET1 peptide and assayed for transcriptional changes by microarray. Mouse dermal fibroblasts were treated with exogenous Et1 peptide for 24 hours. ET1 treatment resulted in significant expression changes primarily downregulation of a number of genes. In particular, Tgf2 and Tgf3 were among the downregulated genes, which in turn alter the expression status of their many target genes. These data suggest that the stable silencing of Et1 is important for the phenotypic stability of dermal fibroblasts, and perhaps many other cell types as well.
Localized methylation in the key regulator gene endothelin-1 is associated with cell type-specific transcriptional silencing.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Phenotypic and genomic analysis of multiple myeloma minimal residual disease tumor cells: a new model to understand chemoresistance.
Specimen part, Disease
View SamplesPersistence of chemoresistant minimal residual disease (MRD) plasma cells (PCs) relates to inferior survival in multiple myeloma (MM). MRD PCs are therefore a minor clone able to recapitulate the initial tumor burden at relapse and accordingly, its characterization may represent a unique model to understand chemoresistance; unfortunately, the MRD clone has never been biologically investigated. Here, we compared the antigenic profile of MRD vs. diagnostic clonal PCs in 40 elderly MM patients enrolled in the GEM2010MAS65 study, and showed that the MRD clone is enriched by cells over-expressing integrins (CD11a/CD11c/CD29/CD49d/CD49e), chemokine receptors (CXCR4) and adhesion molecules (CD44/CD54). Genetic profiling of MRD vs. diagnostic PCs showed identical copy number alterations (CNAs) in 3/8 cases, 2 patients with linear acquisition of additional CNAs in MRD clonal PCs, and 3 cases with variable acquisition and loss of CNAs over time. The MRD clone showed significant downregulation of genes particularly related to protein processing in endoplasmic reticulum, as well as novel deregulated genes such as ALCAM that is prognostically relevant in MM and identifies chemoresistant PCs in vitro. Together, we show that therapy-induced clonal selection is already present at the MRD stage, in which chemoresistant PCs show a specific phenotypic signature that may result from the persistence of clones with different genetic and gene expression profiles.
Phenotypic and genomic analysis of multiple myeloma minimal residual disease tumor cells: a new model to understand chemoresistance.
Specimen part, Disease
View SamplesCertain neuron types fire spontaneously at high rates, an ability that is crucial for their function in brain circuits. The spontaneously active GABAergic neurons of the substantia nigra pars reticulata (SNr), a major output of the basal ganglia, provide tonic inhibition of downstream brain areas. A depolarizing "leak" current supports this firing pattern, but its molecular basis remains poorly understood. To understand how SNr neurons maintain tonic activity, we used single-cell RNA sequencing to determine the transcriptome of individual SNr neurons. We discovered that SNr neurons express the sodium leak current, NaLCN and that SNr neurons lacking NaLCN have impaired spontaneous firing. Overall design: RNA sequencing profiles from 87 GFP-positive GABAergic SNr neurons and 9 GFP-negative SNr cells were carried out. However only 80 samples that passed initial quality control and that were included in the data processing are represented in this record.
The leak channel NALCN controls tonic firing and glycolytic sensitivity of substantia nigra pars reticulata neurons.
Specimen part, Cell line, Subject
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