AID-dependent U/G mismatches in S DNA are converted by BER and MMR DNA pathways into double-stranded breaks that are required for optimal CSR in activated B cells. Deficits in MMR proteins, MSH2, MLH1, and PMS2 result in lower CSR frequencies that are coupled with impaired DSB formation. MBD4 interacts with MLH1 and has been postulated to coordinate mismatch repair of U/G. Deletions of Mbd4 targeting the 5' end of the gene in mice do not affect CSR . However, Mbd4 transcription is complex, with the propensity to create alternative transcripts, including residual transcription leading to to truncated protein expression that complicates ananlysis in these mice. We describe a novel function of MBD4 housed in the C-terminus that is critical for DSB formation, which shares several characteristics with MMR . We conclude that the 3' end of the Mbd4 gene positively contributes to CSR and likely intersects the MMR pathway.
MBD4 Facilitates Immunoglobulin Class Switch Recombination.
Cell line, Treatment
View SamplesIn cervical cancer, an important mechanism by which tumour cells escape immune surveillance is loss of HLA class I, enabling tumours to evade recognition and lysis by cytotoxic T lymphocytes. Some tumours, however, escape from immune surveillance without accumulating defects in antigen presentation. We hypothesized that tumours with no or partial loss of HLA class I develop alternative mechanisms to prevent immune surveillance. To investigate this hypothesis, genome-wide expression profiling using Illumina arrays was performed on cervical squamous cell carcinomas showing overall loss of HLA class I, partial and normal HLA class I protein expression. Statistical analyses revealed no significant differences in gene expression between tumours with partial (n = 11) and normal HLA class I expression (n = 10). Comparison of tumours with normal/partial HLA class I expression (n = 21) with those with overall loss of HLA class I expression (n = 11) identified 150 differentially expressed genes. Most of these genes were involved in the defense response (n = 27), and, in particular, inflammatory and acute phase responses. Especially SerpinA1 and SerpinA3 were found to be upregulated in HLA positive tumours (3.6 and 8.2 fold, respectively), and this was confirmed by real-time PCR and immunohistochemistry. In a group of 117 tumours, high SerpinA1 and SerpinA3 expression in association with normal/partial HLA expression correlated significantly with poor overall survival (p = 0.035 and p = 0.05, respectively). This study shows that HLA positive tumours are characterized by a higher expression of genes associated with an inflammatory profile and that expression of the acute phase proteins SerpinA1 and SerpinA3 in HLA positive tumours is associated with worse prognosis.
Elevated expression of SerpinA1 and SerpinA3 in HLA-positive cervical carcinoma.
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View SamplesIn acute myeloid leukemia, chemotherapy resistance remains prevalent and poorly understood. Using functional proteomics of patient AML specimens, we identified MEF2C S222 phosphorylation as a specific marker of primary chemoresistance. We found that transgenic Mef2cS222A/S222A mice engineered to block MEF2C phosphorylation exhibited normal hematopoiesis, but were resistant to leukemogenesis induced by MLL-AF9. MEF2C phosphorylation was required for leukemia stem cell maintenance, induced by MARK kinases in cells, and blocked by selective MARK inhibitor MRT199665, which caused apoptosis of MEF2C-activated human AML cell lines and primary patient specimens, but not those lacking MEF2C. These findings identify signaling-dependent dysregulation of transcription factor control as a determinant of therapy response in AML, with immediate potential for improved diagnosis and therapy for this disease. Overall design: RNA-sequencing of human leukemia cell line with induction of wildtype or mutant MEF2C.
MEF2C Phosphorylation Is Required for Chemotherapy Resistance in Acute Myeloid Leukemia.
Specimen part, Cell line, Treatment, Subject
View SamplesIn acute myeloid leukemia, chemotherapy resistance remains prevalent and poorly understood. Using functional proteomics of patient AML specimens, we identified MEF2C S222 phosphorylation as a specific marker of primary chemoresistance. We found that transgenic Mef2cS222A/S222A mice engineered to block MEF2C phosphorylation exhibited normal hematopoiesis, but were resistant to leukemogenesis induced by MLL-AF9. MEF2C phosphorylation was required for leukemia stem cell maintenance, induced by MARK kinases in cells, and blocked by selective MARK inhibitor MRT199665, which caused apoptosis of MEF2C-activated human AML cell lines and primary patient specimens, but not those lacking MEF2C. These findings identify signaling-dependent dysregulation of transcription factor control as a determinant of therapy response in AML, with immediate potential for improved diagnosis and therapy for this disease. Overall design: RNA-sequencing of human leukemia cell line with treatment of MARK inhibitor MRT199665.
MEF2C Phosphorylation Is Required for Chemotherapy Resistance in Acute Myeloid Leukemia.
Specimen part, Cell line, Treatment, Subject
View SamplesTo identify genes regulated by Rx3 during optic vesicle morphogenesis, adult zebrafish carriers of a null rx3 mutation were mated. Before 13 hours post fertilization (hpf), the earliest time point at which optic vesicle evagination phenotypes could be reliably detected, offspring were phenotypically separated into pools comprising of mutants with an absence of optic vesicles or siblings exhibiting a wild-type phenotype. Three replicates of pooled RNA samples from 13 hpf eyeless mutants (rx3-/-) or phenotypically wild-type siblings (rx3+/+ or rx3+/-), and one replicate of 13 hpf wild-type zebrafish larva were collected for whole transcriptome sequencing. Overall design: Whole transcriptome sequencing (RNA-seq) was performed on zebrafish rx3-/- mutants, wild-type siblings and wild-type AB strains at 13 hpf
Genes and signaling networks regulated during zebrafish optic vesicle morphogenesis.
No sample metadata fields
View SamplesUnderstanding distinct gene expression patterns of normal adult and developing fetal human pancreatic a and b cells is crucial for developing stem cell therapies, islet regeneration strategies, and therapies designed to increase b cell function in patients with diabetes (type 1 or 2). Toward that end, we have developed methods to highly purify a, b, and d cells from human fetal and adult pancreata by intracellular staining for the cell-specific hormone content, sorting the sub-populations by flow cytometry and, using next generation RNA sequencing, we report on the detailed transcriptomes of fetal and adult a and b cells. We observed that human islet composition was not influenced by age, gender, or body mass index and transcripts for inflammatory gene products were noted in fetal b cells. In addition, within highly purified adult glucagon-expressing a cells, we observed surprisingly high insulin mRNA expression, but not insulin protein expression. This transcriptome analysis from highly purified islet a and b cell subsets from fetal and adult pancreata offers clear implications for strategies that seek to increase insulin expression in type 1 and type 2 diabetes. Overall design: RNA-sequencing of highly purified human adult and fetal islet cell subset was performed using our newly developed method. Using this data, we can study and compare the detailed transcriptome or alpha and beta cells during development.
Novel Observations From Next-Generation RNA Sequencing of Highly Purified Human Adult and Fetal Islet Cell Subsets.
No sample metadata fields
View SamplesTCDD increased expression of numerous differentiation specific genes and decreased expression of numerous genes involved in mitochondrial health and redox homeostasis
2,3,7,8-Tetrachlorodibenzo-p-dioxin-mediated production of reactive oxygen species is an essential step in the mechanism of action to accelerate human keratinocyte differentiation.
Specimen part, Cell line
View SamplesRcho-1 trophoblast stem cells can be maintained in a trophoblast stem cell state or induced to differentiate into trophoblast giant cells. During the differentiation process the PI3K pathway is constitutively activated.
Phosphatidylinositol 3 kinase modulation of trophoblast cell differentiation.
Specimen part, Cell line
View SamplesIn hemochorial placentation, trophoblast stem cells differentiate into multiple lineages to aquire specific functions, such as invasive and endocrine phenotype. FOSL1 has been identified as a key regulator for trophoblast differentiation. We used microarray to detail mechanisms underlying FOSL1 signaling pathway in trophoblast differentiation.
Dynamic Regulation of AP-1 Transcriptional Complexes Directs Trophoblast Differentiation.
Specimen part, Cell line
View SamplesWIN 18,446/RA treatment of neonatal male mice was used to synchronize spermatogenesis to 2-3 different stages of the cycle of the seminiferous epithelium in the adult testis
Processive pulses of retinoic acid propel asynchronous and continuous murine sperm production.
Sex, Specimen part
View Samples