DACH1 suppresses breast cancer as a negative regulator of CD44.

Dachshund homolog 1 (DACH1), a key cell fate determination factor, contributes to tumorigenesis, invasion, metastasis of human breast neoplasm. However, the exact molecular mechanisms for the anti-tumor roles of DACH1 in breast carcinoma are still lack of extensive understanding. Herein, we utilized immunohistochemistry (IHC) staining and public microarray data analysis showing that DACH1 was higher in normal breast, low-grade and luminal-type cancer in comparison with breast carcinoma, high-grade and basal-like tumors respectively. Additionally, both correlation analysis of public databases of human breast carcinoma and IHC analysis of mice xenograft tumors demonstrated that DACH1 inversely related to cancer stem cells (CSCs) markers, epithelial-mesenchymal transition (EMT) inducers and basal-enriched molecules, while cluster of differentiation 44 (CD44) behaved in an opposite manner. Furthermore, mice transplanted tumor model indicated that breast cancer cells Met-1 with up-regulation of DACH1 were endowed with remarkably reduced potential of tumorigenesis. Importantly, meta-analysis of 19 Gene Expression Omnibus (GEO) databases of breast cancer implicated that patients with higher DACH1 expression had prolonged time to death, recurrence and metastasis, while CD44 was a promising biomarker predicting worse overall survival (OS) and metastasis-free survival (MFS). Collectively, our study indicated that CD44 might be a novel target of DACH1 in breast carcinoma

DACH1: its role as a classifier of long term good prognosis in luminal breast cancer

Background: Oestrogen receptor (ER) positive (luminal) tumours account for the largest proportion of females with breast cancer. Theirs is a heterogeneous disease presenting clinical challenges in managing their treatment. Three main biological luminal groups have been identified but clinically these can be distilled into two prognostic groups in which Luminal A are accorded good prognosis and Luminal B correlate with poor prognosis. Further biomarkers are needed to attain classification consensus. Machine learning approaches like Artificial Neural Networks (ANNs) have been used for classification and identification of biomarkers in breast cancer using high throughput data. In this study, we have used an artificial neural network (ANN) approach to identify DACH1 as a candidate luminal marker and its role in predicting clinical outcome in breast cancer is assessed. Materials and methods: A reiterative ANN approach incorporating a network inferencing algorithm was used to identify ER- associated biomarkers in a publically available cDNA microarray dataset. DACH1 was identified in having a strong influence on ER associated markers and a positive association with ER. Its clinical relevance in predicting breast cancer specific survival was investigated by statistically assessing protein expression levels after immunohistochemistry in a series of unselected breast cancers, formatted as a tissue microarray. Results: Strong nuclear DACH1 staining is more prevalent in tubular and lobular breast cancer. Its expression correlated with ER-alpha positive tumours expressing PgR, epithelial cytokeratins (CK)18/19 and 'luminal-like' markers of good prognosis including FOXA1 and RERG (p , 0.05). DACH1 is increased in patients showing longer cancer specific survival and disease free interval and reduced metastasis formation (p , 0.001). Nuclear DACH1 showed a negative association with markers of aggressive growth and poor prognosis. Conclusion: Nuclear DACH1 expression appears to be a Luminal A biomarker predictive of good prognosis, but is not independent of clinical stage, tumour size, NPI status or systemic therapy

Dynamic and cell-specific DACH1 expression in human neocortical and striatal development

DACH1 is the human homolog of the Drosophila dachshund gene, which is involved in the development of the eye, nervous system, and limbs in the fly. Here, we systematically investigate DACH1 expression patterns during human neurodevelopment, from 5 to 21 postconceptional weeks. By immunodetection analysis, we found that DACH1 is highly expressed in the proliferating neuroprogenitors of the developing cortical ventricular and subventricular regions, while it is absent in the more differentiated cortical plate. Single-cell global transcriptional analysis revealed that DACH1 is specifically enriched in neuroepithelial and ventricular radial glia cells of the developing human neocortex. Moreover, we describe a previously unreported DACH1 expression in the human striatum, in particular in the striatal medium spiny neurons. This finding qualifies DACH1 as a new striatal projection neuron marker, together with PPP1R1B, BCL11B, and EBF1. We finally compared DACH1 expression profile in human and mouse forebrain, where we observed spatio-temporal similarities in its expression pattern thus providing a precise developmental description of DACH1 in the 2 mammalian species

\u3cem\u3eDACH1\u3c/em\u3e Mutation Frequency in Endometrial Cancer Is Associated with High Tumor Mutation Burden

OBJECTIVE: DACH1 is a transcriptional repressor and tumor suppressor gene frequently mutated in melanoma, bladder, and prostate cancer. Loss of DACH1 expression is associated with poor prognostic features and reduced overall survival in uterine cancer. In this study, we utilized the Oncology Research Information Exchange Network (ORIEN) Avatar database to determine the frequency of DACH1 mutations in patients with endometrial cancer in our Kentucky population. METHODS: We obtained clinical and genomic data for 65 patients with endometrial cancer from the Markey Cancer Center (MCC). We examined the clinical attributes of the cancers by DACH1 status by comparing whole-exome sequencing (WES), RNA Sequencing (RNASeq), microsatellite instability (MSI), and tumor mutational burden (TMB). RESULTS: Kentucky women with endometrial cancer had an increased frequency of DACH1 mutations (12/65 patients, 18.5%) compared to The Cancer Genome Atlas (TCGA) endometrial cancer population (25/586 patients, 3.8%) with p-value = 1.04E-05. DACH1 mutations were associated with increased tumor mutation count in both TCGA (median 65 vs. 8972, p-value = 7.35E-09) and our Kentucky population (490 vs. 2160, p-value = 6.0E-04). DACH1 mutated patients have a higher tumor mutation burden compared to DACH1 wild-type (24 vs. 6.02, p-value = 4.29E-05). DACH1 mutations showed significant gene co-occurrence patterns with POLE, MLH1, and PMS2. DACH1 mutations were not associated with an increase in microsatellite instability at MCC (MSI-H) (p-value = 0.1342). CONCLUSIONS: DACH1 mutations are prevalent in Kentucky patients with endometrial cancer. These mutations are associated with high tumor mutational burden and co-occur with genome destabilizing gene mutations. These findings suggest DACH1 may be a candidate biomarker for future trials with immunotherapy, particularly in endometrial cancers

Investigating the role of Dachshund Homolog 1 (DACH1) and miR-200b in Group 4 medulloblastoma pathogenesis

Medulloblastoma is the most common malignant childhood brain tumour, and the most significant cause of childhood cancer-related mortality. Recently four core molecular medulloblastoma sub-groups have been identified, with distinct pathogenesis and responses to therapies. Current therapies, do not account for this molecular variation, and many patients may receive inappropriate treatment. To address this, targeted therapies for each molecular sub-group would be ideal. Unfortunately, for the more aggressive Group 3 and Group 4 subgroups, the underlying mechanisms of pathogenesis remain poorly understood. The current challenge is to identify the key tumour suppressors or oncogenes involved in Group 3 and Group 4 pathogenesis, which may ultimately lead to the development of new therapeutic targets. Transcriptional profiling studies of medulloblastoma have identified numerous genes commonly affected in other cancers, which may also contribute to medulloblastoma pathogenesis. One potential candidate is Dachshund Homolog 1 (DACH1), which has upregulated expression across all medulloblastoma sub-groups, relative to normal cerebellum, consistent with a potential oncogenic role. This up-regulation is most significant in the Group 4 tumours and is consistent with recent methylation profiling analyses, correlating increased DACH1 expression with gene hypomethylation. This combined evidence suggests that DACH1 may be a medulloblastoma oncogene. Oncogenic over-expression of DACH1 has been demonstrated in both ovarian and colorectal cancers, and is associated with cancer progression and invasiveness, but has not previously been linked to medulloblastoma pathogenesis. Additionally the mechanisms associated with over-expression of DACH1 have not been explored in any cancers; however epigenetic modulation is likely, as DACH1 mutations are relatively rare in most cancer types, and DACH1 mutations in medulloblastoma have not been identified. Deregulated expression of numerous microRNAs has been identified in various cancers, including medulloblastoma, demonstrating the role of microRNAs in cancer initiation and progression. MicroRNAs provide a potential epigenetic mechanism for regulation of DACH1. Analysis of the DACH1 3’UTR using TargetScan revealed a potential binding sites for nine individual/clusters of miRNAs (Figure 10). One putative miRNA is miR-200b, belonging to the highly conserved microRNA-200 family (miR-200). miR-200 is frequently down-regulated in metastatic cancers, raising the possibility that the miR-200 family may play a role in the pathogenesis of metastatic Group 4 medulloblastoma. There is an apparent association between high levels of DACH1 expression and low level of miR-200b, and in silico analysis using TargetScan identified a putative binding site for miR- 200b within the DACH1 3’-UTR at nucleotides 971-978. Previous evidence supports the role of both DACH1 and miR-200b in metastatic progression; however an association between the two has not previously been described. Here we propose that deregulated DACH1 was associated with loss of regulation by miR-200b, and demonstrated an inverse correlation between DACH1 and mir-200b expression in representative medulloblastoma cell lines, which was further assessed

The endogenous cell-fate factor dachshund restrains prostate epithelial cell migration via repression of cytokine secretion via a cxcl signaling module.

Prostate cancer is the second leading form of cancer-related death in men. In a subset of prostate cancer patients, increased chemokine signaling IL8 and IL6 correlates with castrate-resistant prostate cancer (CRPC). IL8 and IL6 are produced by prostate epithelial cells and promote prostate cancer cell invasion; however, the mechanisms restraining prostate epithelial cell cytokine secretion are poorly understood. Herein, the cell-fate determinant factor DACH1 inhibited CRPC tumor growth in mice. Using Dach1(fl/fl)/Probasin-Cre bitransgenic mice, we show IL8 and IL6 secretion was altered by approximately 1,000-fold by endogenous Dach1. Endogenous Dach1 is shown to serve as a key endogenous restraint to prostate epithelial cell growth and restrains migration via CXCL signaling. DACH1 inhibited expression, transcription, and secretion of the CXCL genes (IL8 and IL6) by binding to their promoter regulatory regions in chromatin. DACH1 is thus a newly defined determinant of benign and malignant prostate epithelium cellular growth, migration, and cytokine abundance in vivo

Genomic Analysis of Stress Response Against Arsenic in \u3cem\u3eCaenorhabditis elegans\u3c/em\u3e

Arsenic, a known human carcinogen, is widely distributed around the world and found in particularly high concentrations in certain regions including Southwestern US, Eastern Europe, India, China, Taiwan and Mexico. Chronic arsenic poisoning affects millions of people worldwide and is associated with increased risk of many diseases including arthrosclerosis, diabetes and cancer. In this study, we explored genome level global responses to high and low levels of arsenic exposure in Caenorhabditis elegans using Affymetrix expression microarrays. This experimental design allows us to do microarray analysis of dose-response relationships of global gene expression patterns. High dose (0.03%) exposure caused stronger global gene expression changes in comparison with low dose (0.003%) exposure, suggesting a positive dose-response correlation. Biological processes such as oxidative stress, and iron metabolism, which were previously reported to be involved in arsenic toxicity studies using cultured cells, experimental animals, and humans, were found to be affected in C. elegans. We performed genome-wide gene expression comparisons between our microarray data and publicly available C. elegans microarray datasets of cadmium, and sediment exposure samples of German rivers Rhine and Elbe. Bioinformatics analysis of arsenic-responsive regulatory networks were done using FastMEDUSA program. FastMEDUSA analysis identified cancer-related genes, particularly genes associated with leukemia, such as dnj-11, which encodes a protein orthologous to the mammalian ZRF1/MIDA1/MPP11/DNAJC2 family of ribosome-associated molecular chaperones. We analyzed the protective functions of several of the identified genes using RNAi. Our study indicates that C. elegans could be a substitute model to study the mechanism of metal toxicity using high-throughput expression data and bioinformatics tools such as FastMEDUSA

Comprehensive methylome map of lineage commitment from haematopoietic progenitors.

Epigenetic modifications must underlie lineage-specific differentiation as terminally differentiated cells express tissue-specific genes, but their DNA sequence is unchanged. Haematopoiesis provides a well-defined model to study epigenetic modifications during cell-fate decisions, as multipotent progenitors (MPPs) differentiate into progressively restricted myeloid or lymphoid progenitors. Although DNA methylation is critical for myeloid versus lymphoid differentiation, as demonstrated by the myeloerythroid bias in Dnmt1 hypomorphs, a comprehensive DNA methylation map of haematopoietic progenitors, or of any multipotent/oligopotent lineage, does not exist. Here we examined 4.6 million CpG sites throughout the genome for MPPs, common lymphoid progenitors (CLPs), common myeloid progenitors (CMPs), granulocyte/macrophage progenitors (GMPs), and thymocyte progenitors (DN1, DN2, DN3). Marked epigenetic plasticity accompanied both lymphoid and myeloid restriction. Myeloid commitment involved less global DNA methylation than lymphoid commitment, supported functionally by myeloid skewing of progenitors following treatment with a DNA methyltransferase inhibitor. Differential DNA methylation correlated with gene expression more strongly at CpG island shores than CpG islands. Many examples of genes and pathways not previously known to be involved in choice between lymphoid/myeloid differentiation have been identified, such as Arl4c and Jdp2. Several transcription factors, including Meis1, were methylated and silenced during differentiation, indicating a role in maintaining an undifferentiated state. Additionally, epigenetic modification of modifiers of the epigenome seems to be important in haematopoietic differentiation. Our results directly demonstrate that modulation of DNA methylation occurs during lineage-specific differentiation and defines a comprehensive map of the methylation and transcriptional changes that accompany myeloid versus lymphoid fate decisions

Nucleocytosolic depletion of the energy metabolite acetyl-coenzyme a stimulates autophagy and prolongs lifespan.

Healthy aging depends on removal of damaged cellular material that is in part mediated by autophagy. The nutritional status of cells affects both aging and autophagy through as-yet-elusive metabolic circuitries. Here, we show that nucleocytosolic acetyl-coenzyme A (AcCoA) production is a metabolic repressor of autophagy during aging in yeast. Blocking the mitochondrial route to AcCoA by deletion of the CoA-transferase ACH1 caused cytosolic accumulation of the AcCoA precursor acetate. This led to hyperactivation of nucleocytosolic AcCoA-synthetase Acs2p, triggering histone acetylation, repression of autophagy genes, and an age-dependent defect in autophagic flux, culminating in a reduced lifespan. Inhibition of nutrient signaling failed to restore, while simultaneous knockdown of ACS2 reinstated, autophagy and survival of ach1 mutant. Brain-specific knockdown of Drosophila AcCoA synthetase was sufficient to enhance autophagic protein clearance and prolong lifespan. Since AcCoA integrates various nutrition pathways, our findings may explain diet-dependent lifespan and autophagy regulation