High-risk human papillomavirus (hrHPV) types induce immortalization of primary human epithelial cells. Previously we demonstrated that immortalization of human foreskin keratinocytes (HFKs) is HPV type dependent, as reflected by the presence or absence of a crisis period before reaching immortality. This study determined how the immortalization capacity of ten hrHPV types relates to DNA damage induction and overall genomic instability in HFKs.
View Article and Find Full Text PDFFanconi anemia (FA) is an inherited disorder characterized by malformations, marrow failure, and predisposition to cancer. Birth defects and laboratory features are characteristic and helpful in diagnosis, when present. Chromosome fragility is pathognomonic in the diagnosis.
View Article and Find Full Text PDFFanconi anemia (FA) is an inherited bone marrow failure syndrome caused by mutations in DNA repair genes; some of these patients may have features of the VACTERL association. Autosomal recessive mutations in FANCI are a rare cause of FA. We identified FANCI mutations by next generation sequencing in three patients in our FA cohort among several whose mutated gene was unknown.
View Article and Find Full Text PDFWarsaw breakage syndrome (WABS) is caused by defective DDX11, a DNA helicase that is essential for chromatid cohesion. Here, a paired genome-wide siRNA screen in patient-derived cell lines reveals that WABS cells do not tolerate partial depletion of individual APC/C subunits or the spindle checkpoint inhibitor p31(comet). A combination of reduced cohesion and impaired APC/C function also leads to fatal mitotic arrest in diploid RPE1 cells.
View Article and Find Full Text PDFThe diagnosis of VACTERL syndrome can be elusive, especially in the prenatal life, due to the presence of malformations that overlap those present in other genetic conditions, including the Fanconi anemia (FA). We report on three VACTERL cases within two families, where the two who arrived to be born died shortly after birth due to severe organs' malformations. The suspicion of VACTERL association was based on prenatal ultrasound assessment and postnatal features.
View Article and Find Full Text PDFFanconi anemia (FA) is a genetically heterogeneous syndrome associated with increased cancer predisposition. The underlying genes govern the FA pathway which functions to protect the genome during the S-phase of the cell cycle. While upregulation of FA genes has been linked to chemotherapy resistance, little is known about their regulation in response to proliferative stimuli.
View Article and Find Full Text PDFHPV-related HNSCC generally have a better prognosis than HPV-negative HNSCC. However, a subgroup of HPV-positive tumors with poor prognosis has been recognized, particularly related to smoking, EGFR overexpression and chromosomal instability. Viral integration into the host genome might contribute to carcinogenesis, as is shown for cervical carcinomas.
View Article and Find Full Text PDFPurpose: Poly(ADP-ribose) polymerase (PARP) inhibitors are promising targeted treatment options for hereditary breast tumors with a homologous recombination (HR) deficiency caused by BRCA1 or BRCA2 mutations. However, the functional consequence of BRCA gene mutations is not always known and tumors can be HR deficient for other reasons than BRCA gene mutations. Therefore, we aimed to develop a functional test to determine HR activity in tumor samples to facilitate selection of patients eligible for PARP inhibitor treatment.
View Article and Find Full Text PDFFanconi anemia (FA) is a rare recessive disorder with chromosomal instability, congenital abnormalities, and a high cancer risk. The breast cancer susceptibility gene BRCA2 (FANCD1) is one of the 16 genes involved in this recessive disease. We have identified a novel mutation of the splice donor site of intron 1 in the noncoding region of BRCA2 in a Japanese FA family.
View Article and Find Full Text PDFThe replicative machinery encounters many impediments, some of which can be overcome by lesion bypass or replication restart pathways, leaving repair for a later time. However, interstrand crosslinks (ICLs), which preclude DNA unwinding, are considered absolute blocks to replication. Current models suggest that fork collisions, either from one or both sides of an ICL, initiate repair processes required for resumption of replication.
View Article and Find Full Text PDFFanconi anemia (FA) is a rare genomic instability disorder characterized by progressive bone marrow failure and predisposition to cancer. FA-associated gene products are involved in the repair of DNA interstrand crosslinks (ICLs). Fifteen FA-associated genes have been identified, but the genetic basis in some individuals still remains unresolved.
View Article and Find Full Text PDFFanconi anemia (FA) is a heterogeneous recessive disorder associated with a markedly elevated risk to develop cancer. To date sixteen FA genes have been identified, three of which predispose heterozygous mutation carriers to breast cancer. The FA proteins work together in a genome maintenance pathway, the so-called FA/BRCA pathway which is important during the S phase of the cell cycle.
View Article and Find Full Text PDFFanconi anaemia (FA) is a rare autosomal recessive or X-linked inherited disease characterised by an increased incidence of bone marrow failure (BMF), haematological malignancies and solid tumours. Cells from individuals with FA show a pronounced sensitivity to DNA interstrand crosslink (ICL)-inducing agents, which manifests as G2-M arrest, chromosomal aberrations and reduced cellular survival. To date, mutations in at least 15 different genes have been identified that cause FA; the products of all of these genes are thought to function together in the FA pathway, which is essential for ICL repair.
View Article and Find Full Text PDFSLX4/FANCP is a recently discovered novel disease gene for Fanconi anemia (FA), a rare recessive disorder characterized by chromosomal instability and increased cancer susceptibility. Three of the 15 FA genes are breast cancer susceptibility genes in heterozygous mutation carriers--BRCA2, PALB2, and BRIP1. To investigate if defects in SLX4 also predispose to breast cancer, the gene was sequenced in a cohort of 729 BRCA1/BRCA2-negative familial breast cancer cases.
View Article and Find Full Text PDFFanconi anemia (FA) is a rare inherited disease characterized by developmental defects, short stature, bone marrow failure, and a high risk of malignancies. FA is heterogeneous: 15 genetic subtypes have been distinguished so far. A clinical diagnosis of FA needs to be confirmed by testing cells for sensitivity to cross-linking agents in a chromosomal breakage test.
View Article and Find Full Text PDFFanconi anemia (FA) is a rare genetic instability syndrome characterized by developmental defects, bone marrow failure, and a high cancer risk. Fifteen genetic subtypes have been distinguished. The majority of patients (≈85%) belong to the subtypes A (≈60%), C (≈15%) or G (≈10%), while a minority (≈15%) is distributed over the remaining 12 subtypes.
View Article and Find Full Text PDFThe Fanconi anemia (FA) protein network is necessary for repair of DNA interstrand crosslinks (ICLs), but its control mechanism remains unclear. Here we show that the network is regulated by a ubiquitin signaling cascade initiated by RNF8 and its partner, UBC13, and mediated by FAAP20, a component of the FA core complex. FAAP20 preferentially binds the ubiquitin product of RNF8-UBC13, and this ubiquitin-binding activity and RNF8-UBC13 are both required for recruitment of FAAP20 to ICLs.
View Article and Find Full Text PDFFanconi anemia (FA) is a rare inherited syndrome with diverse clinical symptoms including developmental defects, short stature, bone marrow failure, and a high risk of malignancies. Fifteen genetic subtypes have been distinguished so far. The mode of inheritance for all subtypes is autosomal recessive, except for FA-B, which is X-linked.
View Article and Find Full Text PDFThe genetic risk factors that contribute to pancreatic cancers are largely unknown. A new next-generation sequencing study by Roberts and colleagues now adds ATM to the list of pancreatic ductal adenocarcinoma predisposition genes.
View Article and Find Full Text PDFMutations in the human ChlR1 gene are associated with a unique genetic disorder known as Warsaw breakage syndrome characterized by cellular defects in sister chromatid cohesion and hypersensitivity to agents that induce replication stress. A role of ChlR1 helicase in sister chromatid cohesion was first evidenced by studies of the yeast homolog Chl1p; however, its cellular functions in DNA metabolism are not well understood. We carefully examined the DNA substrate specificity of purified recombinant human ChlR1 protein and the biochemical effect of a patient-derived mutation, a deletion of a single lysine (K897del) in the extreme C terminus of ChlR1.
View Article and Find Full Text PDFFanconi anaemia (FA) is a rare recessive disorder marked by developmental abnormalities, bone marrow failure, and a high risk for the development of leukaemia and solid tumours. The inactivation of FA genes, in particular FANCF, has also been documented in sporadic tumours in non-FA patients. To study whether there is a causal relationship between FA pathway defects and tumour development, we have generated a mouse model with a targeted disruption of the FA core complex gene Fancf.
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