Epithelial-mesenchymal transition (EMT) is a pivotal process in development and disease. In carcinogenesis, various signaling pathways are known to trigger EMT by inducing the expression of EMT transcription factors (EMT-TFs) like SNAIL1, ultimately promoting invasion, metastasis and chemoresistance. However, how EMT is executed downstream of EMT-TFs is incompletely understood. Here, using human colorectal cancer (CRC) and mammary cell line models of EMT, we demonstrate that SNAIL1 critically relies on bone morphogenetic protein (BMP) signaling for EMT execution. This activity requires the transcription factor SMAD4 common to BMP/TGFβ pathways, but is TGFβ signaling-independent. Further, we define a signature of BMP-dependent genes in the EMT-transcriptome which orchestrate EMT-induced invasiveness, and are found to be regulated in human CRC transcriptomes and during EMT in vivo. Collectively, our findings substantially augment the knowledge of mechanistic routes whereby EMT can be effectuated, which is relevant for the conceptual understanding and therapeutic targeting of EMT processes.
Canonical BMP Signaling Executes Epithelial-Mesenchymal Transition Downstream of SNAIL1.
Specimen part
View SamplesGene expression levels are determined by the balance between rates of mRNA transcription and decay, and genetic variation in either of these processes can result in heritable differences in transcript abundance. Although the genetics of gene expression has been the subject of intense interest, the contribution of heritable variation in mRNA decay rates to gene expression variation has received far less attention. To this end, we developed a novel statistical framework and measured allele-specific differences in mRNA decay rates in a diploid yeast hybrid created by mating two genetically diverse parental strains. In total, we estimate that 31% of genes exhibit allelic differences in mRNA decay rate, of which 350 can be identified at a false discovery rate of 10%. Genes with significant allele-specific differences in mRNA decay rate have higher levels of polymorphism compared to other genes, with all gene regions contributing to allelic differences in mRNA decay rate. Strikingly, we find widespread evidence for compensatory evolution, such that variants influencing transcriptional initiation and decay having opposite effects, suggesting steady-state gene expression levels are subject to pervasive stabilizing selection. Our results demonstrate that heritable differences in mRNA decay rates are widespread, and are an important target for natural selection to maintain or fine-tune steady-state gene expression levels. Overall design: We measured rates of allele-specific mRNA decay (ASD) in a diploid yeast produced by mating two genetically diverse haploid Saccharomyces cerevisiae strains: the laboratory strain BY4716 (BY), which is isogenic to the reference sequence strain S288C, and the wild Californian vineyard strain RM11-1a (RM). Briefly, we introduced rpb1-1, a temperature sensitive mutation in an RNA polymerase II subunit, to each of the haploid yeast strains, mated the strains, and grew the resulting hybrid diploid to mid-log phase at 24 °C, before rapidly shifting the culture to 37 °C to inhibit transcription. RNA-seq was performed on culture samples taken at 0, 6, 12, 18, 24, and 42 minutes subsequent to the temperature shift. To identify ASD, we used transcribed polymorphisms to distinguish between parental transcripts, and compared the relative levels of transcript abundance over the time course. Note, this experimental design internally controls for trans-acting regulatory variation as well as environmental factors. Under the null hypothesis of no ASD, the proportion of reads from the BY transcript (p_BY = N_BY / (N_BY + N_RM)) observed over the time course remains unchanged. However, genes with ASD will exhibit an increasing or decreasing proportion of BY reads as a function of time. In total, we measured ASD from three independent biological replicates.
Heritable variation of mRNA decay rates in yeast.
Disease, Cell line, Subject
View SamplesPI3K/AKT pathway plays one of pivotal roles in breast cancer development and maintenance. PIK3CA, coding PIK3 catalytic subunit, is the oncogene which shows the high frequency of gain-of-function mutations leading to the PI3K/AKT pathway activation in breast cancer. In particular in the ER-positive breast tumors PIK3CA mutations have been observed in 30% to 40%. However, genes expressed in connection to the pathway activation in breast tumorigenesis remain largely unknown.
Gene expression profiling reveals new aspects of PIK3CA mutation in ERalpha-positive breast cancer: major implication of the Wnt signaling pathway.
Sex, Age, Specimen part
View SamplesTranscriptomic response of mouse mixed neuron-glial cell cultures to 1,25-dihydroxyvitamin D3
The transcriptomic response of mixed neuron-glial cell cultures to 1,25-dihydroxyvitamin d3 includes genes limiting the progression of neurodegenerative diseases.
Specimen part, Treatment
View SamplesMost human cancers present hyperactivated sumoylation, and cancer cell lines are usually highly sensitive to the lack of it, supporting potential application of sumoylation chemical inhibitors in cancer therapy. Here, we explored the impact of hyposumoylation (Ubc9 haploinsufficiency) on cancer development in mice using Apc loss-driven intestinal tumorigenesis model.
An unanticipated tumor-suppressive role of the SUMO pathway in the intestine unveiled by Ubc9 haploinsufficiency.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Genome-wide analysis shows that Ldb1 controls essential hematopoietic genes/pathways in mouse early development and reveals novel players in hematopoiesis.
Specimen part
View SamplesThe Lgr5+ intestinal stem cell, Paneth and transit-amplifying cell compartment constitute the intestinal crypt which is the constant source of differentiated epithelial cells that replenish the intestinal villi ensuring organ maintenance and regeneration. The Lgr5+ crypt-based columnar (CBC) cells have been identified as the intestinal stem cells (ISCs) and, importantly, as cells-of-origin of intestinal cancer.
An unanticipated tumor-suppressive role of the SUMO pathway in the intestine unveiled by Ubc9 haploinsufficiency.
Specimen part
View SamplesThe first site exhibiting hematopoietic activity in mammalian development is the yolk sac blood island, which originates from the hemangioblast. Here we performed differentiation assays, as well as genome-wide molecular and functional studies in BL-CFCs to gain insight into the function of the essential Ldb1 factor in early primitive hematopoietic development. We show that the previously reported lack of yolk sac hematopoiesis and vascular development in Ldb1-/- mouse result from a decreased number of hemangioblasts and a block in their ability to differentiate into erythroid and endothelial progenitor cells. Transcriptome analysis and correlation with the genome wide binding pattern of Ldb1 in hemangioblasts revealed a number of direct target genes and pathways misregulated in the absence of Ldb1. The regulation of essential developmental factors by Ldb1 defines it as an upstream transcriptional regulator of hematopoietic/endothelial development. We show the complex interplay that exists between transcription factors and signaling pathways during the very early stages of hematopoietic/endothelial development and the specific signalling occurring in hemangioblasts in contrast to more advanced hematopoietic developmental stages. Finally, by revealing novel genes and pathways, not previously associated with early development, our study provides novel candidate targets to manipulate the differentiation of hematopoietic and/or endothelial cells.
Genome-wide analysis shows that Ldb1 controls essential hematopoietic genes/pathways in mouse early development and reveals novel players in hematopoiesis.
Specimen part
View SamplesTo determine the impact of ?Np63a knockdown on steady-state mRNA levels, we performed poly(A)-enriched RNA-seq analysis of lung squamous cell carcinoma line H226 (inducible shControl and shp63) in the presence of 1µg/mL doxycycline to induce shRNA expression. Overall design: Poly(A)+ RNA for two independent biological replicates was purified from H226 cells (inducible shControl and shp63) incubated treated for six days with 1 µg/mL doxycycline. a TruSeq Stranded mRNA Library Prep Kit (Illumina). Libraries were sequenced on an Illumina HiSeq 2000 system at the University of Colorado Cancer Center Genomics and Microarray Core facility. Reads were aligned (TopHat2) to the Human reference genome (GRCh37/hg19) and gene-level counts (HTseq-count) were used for differential expression analysis (DESeq2).
ΔNp63α Suppresses TGFB2 Expression and RHOA Activity to Drive Cell Proliferation in Squamous Cell Carcinomas.
Specimen part, Cell line, Treatment, Subject
View SamplesTo determine effects of p53 activation on levels of RNA associated with polysomes, we performed RNA-seq analysis of colorectal carcinoma cell line HCT116, breast carcinoma line MCF7, and osteosarcoma line SJSA treated with MDM2 inhibitor Nutlin. Overall design: Polysomal RNA was extracted from HCT116, MCF7 and SJSA cells treated with Nutlin, polyA enriched and subjected to RNA-seq protocol.
Identification of a core TP53 transcriptional program with highly distributed tumor suppressive activity.
Cell line, Treatment, Subject
View Samples