Project description:<p>Recently, we have identified that variants in <i>CIZ1</i> gene is associated with dystonia. To identify the prevalence of <i>CIZ1</i> mutations in dystonia population, we use High resolution melting (HRM) to examine all the coding sequence in 3976 subjects with primary dystonia as well as 1819 subjects of normal controls. Indels in Q rich region of exon 2 in <i>CIZ1</i> were identified in 21 subjects with dystonia but only 3 controls (P<0.05). Other single nucleotide change variants were also found in some of the patients which include a novel missense mutation (c.787A>G, p.R263G) found in a female patient with apparently familial dystonia. We confirmed that mutations in <i>CIZ1</i> could be associated with dystonia but in rare cases.</p>
Project description:The Shieldin complex, consisting of SHLD1, SHLD2, SHLD3 and REV7, shields double strand DNA breaks (DSBs) from nucleolytic resection. The end-protecting activity of Shieldin promotes productive non-homologous end joining (NHEJ) in G1 but can threaten genome integrity during S-phase by blocking homologous recombination (HR). Curiously, the penultimate Shieldin component, SHLD1 is one of the least abundant mammalian proteins. Here, we report that the transcription factors THAP1, YY1 and HCF1 bind directly to the SHLD1 promoter, where they cooperatively maintain the low basal expression of SHLD1. Functionally, this transcriptional network ensures that SHLD1 protein levels are kept in check to enable a proper balance between end protection and end resection during physiological DSB repair. In the context of BRCA1 deficiency, loss of THAP1 dependent SHLD1 expression confers cross resistance to PARP inhibitor and cisplatin, and shorter progression free survival in ovarian cancer patients. In contrast, loss of THAP1 in BRCA2 deficient cells increases genome instability and correlates with improved responses to chemotherapy. Pathogenic THAP1 mutations are causatively linked to adult-onset torsion dystonia type 6 (DYT6) movement disorder, but the critical disease targets are unknown. We further demonstrate that murine models of Thap1-associated dystonia show reduced Shld1 expression concomitant with elevated levels of unresolved DNA damage in the brain. In summary, our study provides the first example of a transcriptional network that directly controls DSB repair choice and reveals a previously unsuspected link between DNA damage and dystonia.
Project description:The Shieldin complex, consisting of SHLD1, SHLD2, SHLD3 and REV7, shields double strand DNA breaks (DSBs) from nucleolytic resection. The end-protecting activity of Shieldin promotes productive non-homologous end joining (NHEJ) in G1 but can threaten genome integrity during S-phase by blocking homologous recombination (HR). Curiously, the penultimate Shieldin component, SHLD1 is one of the least abundant mammalian proteins. Here, we report that the transcription factors THAP1, YY1 and HCF1 bind directly to the SHLD1 promoter, where they cooperatively maintain the low basal expression of SHLD1. Functionally, this transcriptional network ensures that SHLD1 protein levels are kept in check to enable a proper balance between end protection and end resection during physiological DSB repair. In the context of BRCA1 deficiency, loss of THAP1 dependent SHLD1 expression confers cross resistance to PARP inhibitor and cisplatin, and shorter progression free survival in ovarian cancer patients. In contrast, loss of THAP1 in BRCA2 deficient cells increases genome instability and correlates with improved responses to chemotherapy. Pathogenic THAP1 mutations are causatively linked to adult-onset torsion dystonia type 6 (DYT6) movement disorder, but the critical disease targets are unknown. We further demonstrate that murine models of Thap1-associated dystonia show reduced Shld1 expression concomitant with elevated levels of unresolved DNA damage in the brain. In summary, our study provides the first example of a transcriptional network that directly controls DSB repair choice and reveals a previously unsuspected link between DNA damage and dystonia.
Project description:The Shieldin complex, consisting of SHLD1, SHLD2, SHLD3 and REV7, shields double strand DNA breaks (DSBs) from nucleolytic resection. The end-protecting activity of Shieldin promotes productive non-homologous end joining (NHEJ) in G1 but can threaten genome integrity during S-phase by blocking homologous recombination (HR). Curiously, the penultimate Shieldin component, SHLD1 is one of the least abundant mammalian proteins. Here, we report that the transcription factors THAP1, YY1 and HCF1 bind directly to the SHLD1 promoter, where they cooperatively maintain the low basal expression of SHLD1. Functionally, this transcriptional network ensures that SHLD1 protein levels are kept in check to enable a proper balance between end protection and end resection during physiological DSB repair. In the context of BRCA1 deficiency, loss of THAP1 dependent SHLD1 expression confers cross resistance to PARP inhibitor and cisplatin, and shorter progression free survival in ovarian cancer patients. In contrast, loss of THAP1 in BRCA2 deficient cells increases genome instability and correlates with improved responses to chemotherapy. Pathogenic THAP1 mutations are causatively linked to adult-onset torsion dystonia type 6 (DYT6) movement disorder, but the critical disease targets are unknown. We further demonstrate that murine models of Thap1-associated dystonia show reduced Shld1 expression concomitant with elevated levels of unresolved DNA damage in the brain. In summary, our study provides the first example of a transcriptional network that directly controls DSB repair choice and reveals a previously unsuspected link between DNA damage and dystonia.
Project description:Gene expression studies were performed to identify pathways possibly dysregulated by mutant in the gene GM-NM-1(olf). These experiments employed RNA derived from lymphoblastoid cell lines established for 4 affected carriers and 4 non-carriers. In comparison to endogenous control and other dystonia-associated genes, GNAL was expressed at relatively low levels in lymphoblastoid cell lines. Comparison of whole blood expression profiles of mutation carrying dystonia patients with normal controls
Project description:Spinal interneurons are critical modulators of locomotor circuit function. In the dorsal spinal cord, a set of interneurons called GABApre presynaptically inhibits proprioceptive sensory afferent terminals, thus negatively regulating sensory-motor signaling. While deficits in presynaptic inhibition have been inferred in human locomotor diseases, including dystonia, it remains unknown whether GABApre circuit components are altered in these conditions. In this study, we use developmental timing to show that GABApre neurons are a late Ptf1a-expressing subclass and localize to the intermediate spinal cord. Using a microarray screen to identify genes expressed in this intermediate population, we find the kelch-like family member Klhl14, implicated in dystonia through its direct binding with torsion-dystonia related protein Tor1a. Furthermore, in Tor1a mutant mice in which Klhl14 and Tor1a binding is disrupted (Dyt1ΔE), GABApre-sensory afferent synapse formation is impaired. Our findings suggest a potential contribution of GABApre neurons to the deficits in presynaptic inhibition observed in dystonia.
Project description:DYT1 dystonia is an autosomal-dominantly inherited movement disorder, which is usually caused by a GAG deletion in the TOR1A gene. Due to the reduced penetrance of ~30-40%, the determination of the mutation in a subject is of limited use with regard to actual manifestation of symptoms. In the present study, we used Affymetrix oligonucleotide microarrays to analyze global gene expression in blood samples of 15 manifesting and 15 non-manifesting mutation carriers in order to identify a susceptibility profile beyond the GAG deletion which is associated with the manifestation of symptoms in DYT1 dystonia.We identified a genetic signature which distinguished between asymptomatic mutation carriers and symptomatic DYT1 patients with 86.7% sensitivity and 100% specificity. This genetic signature could correctly predict the disease state in an independent test set with a sensitivity of 87.5% and a specificity of 85.7%.Conclusively, this genetic signature might provide a possibility to distinguish DYT1 patients from asymptomatic mutation carriers. Comparison of whole blood expression profiles of patients with DYT1 dystonia with non manifesting mutation carriers and non mutation carriers
Project description:Most (70%) epithelial ovarian cancers (EOCs) are diagnosed late. Non-invasive biomarkers that facilitate disease detection and predict outcome are needed. The microRNAs (miRNAs) represent a new class of biomarkers. This study was to identify and validate plasma miRNAs as biomarkers in EOC. We evaluated plasma samples of 360 EOC patients and 200 healthy controls from two institutions. All samples were grouped into screening, training and validation sets. We scanned the circulating plasma miRNAs by TaqMan low-density array in the screening set and identified/validated miRNA markers by real-time polymerase chain reaction assay in the training set. Receiver operating characteristic and logistic regression analyses established the diagnostic miRNA panel, which were confirmed in the validationsets. We found higher plasma miR-205 and lower let-7f expression in cases than in controls. MiR-205 and let-7f together provided high diagnostic accuracy for EOC, especially in patients with stage I disease. The combination of these two miRNAs and carbohydrate antigen-125 (CA-125) further improved the accuracy of detection. MiR-483-5p expression was elevated in stages III and IV compared with in stages I and II, which was consistent with its expression pattern in tumor tissues. Furthermore, lower levels of let-7f were predictive of poor prognosis in EOC patients. Our findings indicate that plasma miR-205 and let-7f are biomarkers for ovarian cancer detection that complement CA-125; let-7f may be predictive of ovarian cancer prognosis. We designed a multi-stage, retrospective, nested case-control study to determine whether serum miRNA profiles can be used to predict EOC development. All samples were grouped into screening, training, and validation sets. A total of 560 plasma samples (360 cases and 200 controls) were obtained from Tianjin Medical University Cancer Institute and Hospital (TCIH) and Cancer Center of Nanjing Medical University. The cases and controls were well matched for age. The International Federation of Gynaecology and Obstetrics (FIGO) staging system was used to stage cases. All patients and controls were genetically unrelated, ethnic Han Chinese women who were permanent residents of the urban area of Tianjin and Nanjing. Controls with cardiovascular, respiratory, digestive, urinary, reproductive, and endocrine diseases were excluded. The study protocols were approved by the Tianjin and Nanjing Center review committees. In screening set, to detect generalizable miRNA signatures, we pooled serum samples of 10 early-stage cases (stage I), 10 late-stage cases (stage IIIc-IV), and 10 healthy controls, respectively, and analyzed these three pool samples using a TaqMan low-density array (TLDA set 2.0, Applied Biosystems) chip screening in the discovery stage. In training set, the miRNAs identified in the screening set were validated using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) on individual plasma samples of 76 EOC patients and 30 normal controls. In validation set, the validation set comprised a two-phase process. Promising associations from the screening and training set were evaluated in the validation phase I set, comprising 134 cases and 70 controls from Tianjin Center. The validation phase II set included samples of 77 EOC cases and 50 normal controls were from Tianjin Center and 73 EOC cases and 50 normal controls were from Nanjing Center.