Warsaw Breakage Syndrome associated DDX11 helicase resolves G-quadruplex structures to support sister chromatid cohesion

Warsaw Breakage Syndrome (WABS) is a rare disorder related to cohesinopathies and Fanconi anemia, caused by bi-allelic mutations in DDX11. Here, we report multiple compound heterozygous WABS cases, each displaying destabilized DDX11 protein and residual DDX11 function at the cellular level. Patient-derived cell lines exhibit sensitivity to topoisomerase and PARP inhibitors, defective sister chromatid cohesion and reduced DNA replication fork speed. Deleting DDX11 in RPE1-TERT cells inhibits proliferation and survival in a TP53-dependent manner and causes chromosome breaks and cohesion defects, independent of the expressed pseudogene DDX12p. Importantly, G-quadruplex (G4) stabilizing compounds induce chromosome breaks and cohesion defects which are strongly aggravated by inactivation of DDX11 but not FANCJ. The DNA helicase domain of DD

An Assessment of the Drivers and Barriers for the Deployment of Urban Phosphorus Recovery Technologies: A Case Study of The Netherlands

Phosphorus (P), being one of the building blocks of life, is essential for a multitude of applications, primarily for fertilizer usage. Sustainable management of phosphorus is becoming increasingly important in light of adverse environmental effects, ambiguous reserves, increasing global demand and unilateral dependence. Recovery of phosphorus from the biggest loss stream, communal wastewater, has the potential to tackle each of these problems. The implementation of phosphorus recovery technologies at wastewater treatment plants is not widespread, despite prolonged efforts primarily done by researchers over the past decade. This study aimed to assess the drivers and barriers of a phosphorus recovery transition. Several key stakeholders involved in this transition in The Netherlands were interviewed. The Netherlands was taken as a case study, since it serves as a frontrunner in the implementation of phosphorus recovery technologies. This study shows that the main barriers from the point of view of fertilizer companies are the different and unclear characteristics of the phosphorus recovery product struvite compared to common fertilizers. Moreover, the end-of-waste status of struvite is mentioned as a prominent barrier for a phosphorus transition, since it hinders free market trade. Many water boards indicate that the main barrier is the high investment cost with an uncertain return on investment for onsite struvite recovery processes. The specified main driver for water boards for onsite struvite phosphorus recovery technology is the reduction of maintenance costs, and for phosphorus recovery from sewage sludge ash, the low organic pollutant in the P recovery product

Generation and molecular characterization of head and neck squamous cell lines of fanconi anemia patients

Patients with Fanconi anemia (FA) are prone to develop malignancies at an early age. Besides hematologic malignancies, squamous cell carcinomas in the anogenital region and head and neck are also frequently found in these patients. The aim of this study was to generate a panel of head and neck squamous cell carcinoma (HNSCC) cell lines and xenografts of FA HNSCC, and to characterize these cell lines in comparison with a panel of seven cell lines from patients with sporadic HNSCC. Analyses have been done on sensitivity to DNA cross-linking agents, loss of heterozygosity profile, TP53 mutations, TP53 polymorph isms and the presence of human papillomavirus. Four FA HNSCC cell lines were established. Sensitivity to DTNA cross-linking agents (cisplatin) in the FA HNSCC cell lines was on average 10 times higher as compared with the sporadic HNSCC cell lines. Human papillomavirus was not detected in any of the FA or sporadic cell lines. No differences were found in loss of heterozygosity pattern, TP53 mutation frequency and TP53 polymorphism between FA and sporadic HNSCC cell lines. This is the first report on the generation of squamous cell lines of FA patients. The FA HNSCC cell lines we have,generated may be utilized for future studies and might aid in the development of new preventive therapies for FA patients. The genetic characteristics of these cell lines suggest that FA HNSCC are not.,cry different from sporadic HNSCC, except for the sensitivity to cisplatin which is consistent with the known cellular FA phenotype

Warsaw Breakage Syndrome, a Cohesinopathy Associated with Mutations in the XPD Helicase Family Member DDX11/ChIR1

The iron-sulfur-containing DNA helicases XPD, FANCJ, DDX11, and RTEL represent a small subclass of superfamily 2 helicases. XPD and FANCJ have been connected to the genetic instability syndromes xeroderma pigmentosum and Fanconi anemia. Here, we report a human individual with biallelic mutations in DDX11. Defective DDX11 is associated with a unique cellular phenotype in which features of Fanconi anemia (drug-induced chromosomal breakage) and Roberts syndrome (sister chromatid cohesion defects) coexist. The DDX11-deficient patient represents another cohesinopathy, besides Cornelia de Lange syndrome and Roberts syndrome, and shows that DDX11 functions at the interface between DNA repair and sister chromatid cohesion

Fancm-deficient mice reveal unique features of Fanconi anemia complementation group M

The Fanconi anemia (FA) core complex member FANCM remodels synthetic replication forks and recombination intermediates. Thus far, only one FA patient with FANCM mutations has been described, but the relevance of these mutations for the FA phenotype is uncertain. To provide further experimental access to the FA-M complementation group we have generated Fancm-deficient mice by deleting exon 2. FANCM deficiency caused hypogonadism in mice and hypersensitivity to cross-linking agents in mouse embryonic fibroblasts (MEFs), thus phenocopying other FA mouse models. However, Fancm(delta 2/delta 2) mice also showed unique features atypical for FA mice, including underrepresentation of female Fancm(delta 2/delta 2) mice and decreased overall and tumor-free survival. This increased cancer incidence may be correlated to the role of FANCM in the suppression of spontaneous sister chromatid exchanges as observed in MEFs. In addition, FANCM appeared to have a stimulatory rather than essential role in FANCD2 monoubiquitination. The FA-M mouse model presented here suggests that FANCM functions both inside and outside the FA core complex to maintain genome stability and to prevent tumorigenesi

Tailoring heated intraperitoneal mitomycin C for peritoneal metastases originating from colorectal carcinoma: translational approach to improve survival

BACKGROUND: Patients with peritoneal metastases (PMs) originating from colorectal carcinoma (CRC) are curatively treated by cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) with mitomycin C (MMC). We aim to improve patient selection for HIPEC by predicting MMC sensitivity. METHODS: The MMC sensitivity was determined for 12 CRC cell lines and correlated to mRNA expression of 37 genes related to the Fanconi anaemia (FA)–BRCA pathway, ATM–ATR pathway and enzymatic activation of MMC. Functionality of the FA–BRCA pathway in cell lines was assessed using a chromosomal breakage assay and western blot for key protein FANCD2. Bloom syndrome protein (BLM) was further analysed by staining for the corresponding protein with immunohistochemistry (IHC) on both CRC cell lines (n=12) and patient material (n=20). RESULTS: High sensitivity correlated with a low BLM (P=0.01) and BRCA2 (P=0.02) at mRNA expression level. However, FA–BRCA pathway functionality demonstrated no correlation to MMC sensitivity. In cell lines, weak intensity staining of BLM by IHC correlated to high sensitivity (P=0.04) to MMC. Low BLM protein expression was significantly associated with an improved survival in patients after CRS and HIPEC (P=0.04). CONCLUSIONS: Low BLM levels are associated with high MMC sensitivity and an improved survival after HIPEC