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Basal cell nevus syndrome (also known as Gorlin Syndrome; MIM109400) is an autosomal dominant disorder characterized by recurrent pathological features such as basal cell carcinomas and odontogenic keratocysts as well as skeletal abnormalities. Most affected individuals have point mutations or small insertions or deletions within the PTCH1 gene on human chromosome 9, but there are some cases with more extensive deletion of the region, usually including the neighboring FANCC and/or ERCC6L2 genes. We report a 16‐year‐old patient with a deletion of approximately 400,000 bases which removes only PTCH1 and some non‐coding RNA genes but leaves FANCC and ERCC6L2 intact. In spite of the small amount of DNA for which he is haploid, his phenotype is more extreme than many individuals with longer deletions in the region. This includes early presentation with a large number of basal cell nevi and other skin lesions, multiple jaw keratocysts, and macrosomia. We found that the deletion was in the paternal chromosome, in common with other macrosomia cases. Using public databases, we have examined possible interactions between sequences within and outside the deletion and speculate that a regulatory relationship exists with flanking genes, which is unbalanced by the deletion, resulting in abnormal activation or repression of the target genes and hence the severity of the phenotype.

Objective The Uncoordinated 5A (UNC5A) protein is part of a family of receptors that play roles in axonal pathfinding and cell migration. We previously showed that the Fanconi anemia C protein (FANCC) interacts with UNC5A and delays UNC5A-mediated apoptosis. FANCC is a predominantly cytoplasmic protein that has multiple functions including DNA damage signaling, oxygen radical metabolism, signal transduction, transcriptional regulation and apoptosis. Given the direct interaction between FANCC and UNC5A and that FANCC interferes with UNC5A-mediated apoptosis, we explored the possibility that FANCC might play a role in axonal-like growth processes. Results Here we show that FANCC and UNC5A are localized to regions of neurite outgrowth during neuronal cell differentiation. We also show that absence of FANCC is required for neurite outgrowth. In addition, FANCC seems required for UNC5A expression. Results from this study combined with our previous report suggest that FANCC plays a role in tissue development through the regulation of UNC5A-mediated functions.

Fanconi Anemia (FA) is an inherited disorder of DNA repair with hematologic manifestations that range from anemia to bone marrow failure (BMF) to acute myeloid leukemia (AML). In a murine model of FA (Fancc(−/−) mice), we found BMF was accelerated by repeated attempts to induce emergency (stress) granulopoiesis; the process for granulocyte production during the innate immune response. Fancc(−/−) mice exhibited an impaired granulocytosis response and died with profound anemia during repeated challenge. In the current study, we found erythropoiesis and serum erythropoietin decreased in Fancc(−/−) and wild type (Wt) mice as emergency granulopoiesis peaked. Serum erythropoietin returned to baseline during steady state resumption, and compensatory proliferation of erythroid progenitors was associated with DNA-damage and apoptosis in Fancc(−/−) mice, but not Wt mice. The erythropoietin receptor activates Janus kinase 2 (Jak2) and we found treatment of Fancc(−/−) mice with ruxolitinib (Jak1/2-inhibitor) decreased anemia, enhanced granulocytosis, delayed clonal progression and prolonged survival during repeated emergency granulopoiesis episodes. This was associated with a decrease in DNA damage and apoptosis in Fancc(−/−) erythroid progenitors during this process. Transcriptome analysis of these cells identified enhanced activity of pathways for metabolism of reactive oxygen species, and decreased apoptosis and autophagy related pathways, as major ruxolitinib-effects in Fancc(−/−) mice. In contrast, ruxolitinib primarily influenced pathways involved in proliferation and differentiation in Wt mice. Ruxolitinib is approved for treatment of myeloproliferative disorders and graft versus host disease, suggesting the possibility of translational use as a bone marrow protectant in FA.

Fanconi anemia (FA), an inherited bone marrow failure (BMF) syndrome, caused by mutations in DNA repair genes, is characterized by congenital anomalies, aplastic anemia, high risk of malignancies and extreme sensitivity to alkylating agents. We aimed to study the clinical presentation, molecular diagnosis and genotype-phenotype correlation among patients with FA from the Israeli inherited BMF registry. Overall, 111 patients of Arab (57%) and Jewish (43%) descent were followed for a median of 15 years (range: 0.1-49); 63% were offspring of consanguineous parents. One-hundred patients (90%) had at least one congenital anomaly; over 80% of the patients developed bone marrow failure; 53% underwent hematopoietic stem-cell transplantation; 33% of the patients developed cancer; no significant association was found between hematopoietic stem-cell transplant and solid tumor development. Nearly 95% of the patients tested had confirmed mutations in the Fanconi genes FANCA (67%), FANCC (13%), FANCG (14%), FANCJ (3%) and FANCD1 (2%), including twenty novel mutations. Patients with FANCA mutations developed cancer at a significantly older age compared to patients with mutations in other Fanconi genes (mean 18.5 and 5.2 years, respectively, P=0.001); however, the overall survival did not depend on the causative gene. We hereby describe a large national cohort of patients with FA, the vast majority genetically diagnosed. Our results suggest an older age for cancer development in patients with FANCA mutations and no increased incidence of solid tumors following hematopoietic stem-cell transplant. Further studies are needed to guide individual treatment and follow-up programs.

Emerging evidence has shown that resting quiescent hematopoietic stem cells (HSCs) prefer to utilize anaerobic glycolysis rather than mitochondrial respiration for energy production. Compelling evidence has also revealed that altered metabolic energetics in HSCs underlies the onset of certain blood diseases; however, the mechanisms responsible for energetic reprogramming remain elusive. We recently found that Fanconi anemia (FA) HSCs in their resting state are more dependent on mitochondrial respiration for energy metabolism than on glycolysis. In the present study, we investigated the role of deficient glycolysis in FA HSC maintenance. We observed significantly reduced glucose consumption, lactate production, and ATP production in HSCs but not in the less primitive multipotent progenitors or restricted hematopoietic progenitors of Fanca −/− and Fancc −/− mice compared with that of wild‐type mice, which was associated with an overactivated p53 and TP53‐induced glycolysis regulator, the TIGAR‐mediated metabolic axis. We utilized Fanca −/− HSCs deficient for p53 to show that the p53‐TIGAR axis suppressed glycolysis in FA HSCs, leading to enhanced pentose phosphate pathway and cellular antioxidant function and, consequently, reduced DNA damage and attenuated HSC exhaustion. Furthermore, by using Fanca −/− HSCs carrying the separation‐of‐function mutant p53 R172P transgene that selectively impairs the p53 function in apoptosis but not cell‐cycle control, we demonstrated that the cell‐cycle function of p53 was not required for glycolytic suppression in FA HSCs. Finally, ectopic expression of the glycolytic rate‐limiting enzyme PFKFB3 specifically antagonized p53‐TIGAR‐mediated metabolic reprogramming in FA HSCs. Together, our results suggest that p53‐TIGAR metabolic axis‐mediated glycolytic suppression may play a compensatory role in attenuating DNA damage and proliferative exhaustion in FA HSCs. stem cells 2019;37:937–947, p53 and TP53‐induced glycolysis regulator (TIGAR)‐mediated glycolytic suppression attenuates reactive oxygen species production, reduces DNA damage, ameliorates chromosomal instability, and consequently prevents premature exhaustion of Fanconi anemia hematopoietic stem cells.

Efficient and durable hematopoietic stem cell (HSC) engraftment is essential for successful HSC transplantation (HSCT). Multiple previous studies had demonstrated active participation of specialized bone marrow (BM) niches in regulating HSC engraftment during HSCT.[1][1]–[3][2] Recently, studies

The Fanconi anemia (FA) pathway is essential for the repair of DNA interstrand crosslinks. Central to the pathway is the FA core complex, a ubiquitin ligase of nine subunits that monoubiquitinates the FANCI–FANCD2 (ID) DNA clamp. The 3.1 A structure of the 1.1-MDa human FA core complex, described here, reveals an asymmetric assembly with two copies of all but the FANCC, FANCE and FANCF subunits. The asymmetry is crucial, as it prevents the binding of a second FANCC–FANCE–FANCF subcomplex that inhibits the recruitment of the UBE2T ubiquitin conjugating enzyme, and instead creates an ID binding site. A single active site then ubiquitinates FANCD2 and FANCI sequentially. We also present the 4.2-A structures of the human core–UBE2T–ID–DNA complex in three conformations captured during monoubiquitination. They reveal the core–UBE2T complex remodeling the ID–DNA complex, closing the clamp on the DNA before ubiquitination. Monoubiquitination then prevents clamp opening after release from the core. Cryo-EM structures of the Fanconi anemia core complex reveal insights into the remodeling of the FANCI–FANCD2 DNA clamp, which is essential during the repair of DNA interstrand crosslinks.

Fanconi anemia (FA), a chromosomal instability syndrome, is caused by inherited pathogenic variants in any of 22 FANC genes, that cooperate in the FA/BRCA pathway. This pathway regulates the repair of DNA interstrand crosslinks (ICLs) through homologous recombination. In FA proper repair of ICLs is impaired, and accumulation of toxic DNA double strand breaks occurs. In order to repair this type of DNA damage, FA cells activate alternative error-prone DNA repair pathways, that may lead to the formation of gross structural chromosome aberrations of which radial figures are the hallmark of FA and their segregation during cell division are the origin of subsequent aberrations like translocations, dicentrics and acentric fragments. The deficiency in DNA repair has pleiotropic consequences in the phenotype of patients with FA, including developmental alterations, bone marrow failure and an extreme risk to develop cancer. The mechanisms leading to the physical abnormalities during embryonic development have not been clearly elucidated, however FA has features of premature aging with chronic inflammation mediated by pro-inflammatory cytokines, that results in tissue attrition, selection of malignant clones and cancer onset. Moreover, the effect of the FA/BRCA pathway in germinal cells, evidenced by infertility in patients with FA attests of chromosomal instability and cell death also occurring in the germinal compartment.

Zika virus (ZIKV) is an emerging flavivirus, which when passed through vertical transmission from mother to developing fetus can lead to developmental abnormalities, including microcephaly. While there is mounting evidence that suggests a causal relationship between ZIKV infection and microcephaly, the mechanisms by which ZIKV induces these changes remain to be elucidated. Here, we demonstrate that ZIKV infection of neural stems cells, both in vitro and in vivo, induces macroautophagy to enhance viral replication. At the same time, ZIKV downregulates a number of essential selective autophagy genes, including the Fanconi anemia (FA) pathway genes. Bioinformatics analyses indicate that the transcription factor E2F4 promotes FANCC expression and is downregulated upon ZIKV infection. Gain and loss of function assays indicate that FANCC is essential for selective autophagy and acts as a negative regulator of ZIKV replication. Finally, we show that Fancc KO mice have increased ZIKV infection and autophagy protein levels in various brain regions. Taken together, ZIKV downregulates FANCC to modulate the host antiviral response and simultaneously attenuate neuronal growth., ZIKV hijacks the host machinery to induce macroautophagy and enhance viral replication. It also downregulates the Fanconi anemia gene FANCC that promotes antiviral selective autophagy and neurogenesis.

Among the 22 Fanconi anemia (FA) reported genes, 90% of mutational spectra were found in three genes, namely FANCA (64%), FANCC (12%) and FANCG (8%). Therefore, this study aimed to identify the high-risk deleterious variants in three selected genes (FANCA, FANCC, and FANCG) through various computational approaches. The missense variant datasets retrieved from the UCSC genome browser were analyzed for their pathogenicity, stability, and phylogenetic conservancy. A total of 23 alterations, of which 16 in FANCA, 6 in FANCC and one variant in FANCG, were found to be highly deleterious. The native and mutant structures were generated, which demonstrated a profound impact on the respective proteins. Besides, their pathway analysis predicted many other pathways in addition to the Fanconi anemia pathway, homologous recombination, and mismatch repair pathways. Hence, this is the first comprehensive study that can be useful for understanding the genetic signatures in the development of FA.

Fanconi anemia (FA) is associated with bone marrow failure. Bone marrow (BM) from patients with FA and fanca(−/−) and fancc(−/−) mice are deficient in hematopoietic stem (HSCs) and progenitor cells (HPCs). Decreased HSCs/HPCs compromise their use in human and mouse hematopoietic cell transplantation (HCT) and gene therapy to correct genetic defects causing FA. We reported increased collection of HSCs from mouse bone marrow and mobilized peripheral blood, and human cord blood of normal donors after collection/processing in low (3%) oxygen (physioxia). We assessed comparative contents of long-term (LT)-HSCs from BM of fanca(−/−) and fancc(−/−) when collected/processed at 3% O(2), in order to negate effects of extra physiological shock stress (EPHOSS) induced by collection/processing in ambient air. Collection/processing of BM from fanca(−/−) and fancc(−/−) mice in physioxia demonstrated a ≥3-fold increase in LT-HSCs compared to that in ambient air. This was associated with decreased phenotypic multipotential progenitor cells and functional granulocyte macrophage, erythroid, and multi-potential progenitors, results similar to that for BM from normal donor mice. Increased collection of HSCs could have clinical applicability for gene therapy and HCT.

Fanconi anemia (FA) is a rare genetic disorder associated with a progressive decline in hematopoietic stem cells leading to bone marrow failure. FA is also characterized by a variety of developmental defects including short stature and skeletal malformations. More than half of children affected with FA have radial-ray abnormalities, and many patients have early onset osteopenia/osteoporosis. Although many Fanconi anemia genes have been identified and a molecular pathway defined, the underlying mechanism leading to bone defects remains elusive. To understand the role of FA genes in skeletal development and bone microarchitecture, we evaluated bone physiology during embryogenesis and in adult FancA- and FancC-deficient mice. We found that both FancA-/- and FancC-/- embryos have abnormal skeletal development shown by skeletal malformations, growth delay, and reduced bone mineralization. FancC-/- adult mice present altered bone morphology and microarchitecture with a significant decrease in cortical bone mineral density in a sex-specific manner. Mechanical testing revealed that male but not female FancC-/- mice show reduced bone strength compared with their wild-type littermates. Ex vivo cultures showed that FancA-/- and FancC-/- bone marrow-derived mesenchymal stem cells (BM MSC) have impaired differentiation capabilities together with altered gene expression profiles. Our results suggest that defective bone physiology in FA occurs in utero and possibly results from altered BM MSC function. These results provide valuable insights into the mechanism involved in FA skeletal defects. © 2018 American Society for Bone and Mineral Research.

Interferon consensus sequence–binding protein (Icsbp) is required for terminating emergency granulopoiesis, an episodic event responsible for granulocyte production in response to infections and a key component of the innate immune response. Icsbp inhibits the expression of Stat3 and C/ebpβ, transcription factors essential for initiating and sustaining granulopoiesis, and activates transcription of Fanconi C (FANCC), a DNA repair protein. In prior studies, we noted accelerated bone marrow failure in Fancc−/− mice undergoing multiple episodes of emergency granulopoiesis, associated with apoptosis of bone marrow cells with unrepaired DNA damage. Additionally, we found increased expression of Fanconi C and F proteins during emergency granulopoiesis. These findings suggest that Icsbp protects the bone marrow from DNA damage by increasing activity of the Fanconi DNA repair pathway, but the mechanisms for FANCC activation during initiation of emergency granulopoiesis are unclear. In this study, we observed that Stat3 and C/ebpβ activate FANCC transcription and contribute to DNA repair. Our findings indicate that FancC expression is increased during Stat3- and C/ebpβ-induced initiation of emergency granulopoiesis by these transcription factors and is maintained through termination by Icsbp. Our work reveals that Stat3- and C/ebpβ-mediated FancC expression is a critical component for initiating and sustaining key innate immune responses.

Objective The expression of homologous recombination (HR) genes in high grade ovarian cancer (HGOC) samples from debulking surgeries were correlated to outcomes in patients selected for chemotherapy treatment regimens. Study design RNA was extracted from 96 fresh frozen tumor samples from debulking surgeries from chemotherapy naive patients with HGOC (primary derived surgeries (PDS), n = 55) or following neoadjuvant chemotherapy treatment (NACT), n = 41). The samples were selected for high tumor content by a gynecological pathologist, and cancer cell content was further confirmed using a percent tumor content covariate, and mutation score covariate analysis. Gene expression analysis was performed using a tailored NanoString-based Pancancer Pathway Panel. Cox proportional hazard regression models were used to assess the associations between the expression of 19 HR genes and survival. Results In the PDS group, over-expression of six HR genes (C11orf30, NBN, FANCF, FANCC, FANCB, RAD50) was associated with improved outcome, in contrast to the NACT group where four HR genes (BRCA2, TP53, FANCB, RAD51) were associated with worse outcome. With the adding extent of debulking as a covariate, three HR genes (NBN, FANCF, RAD50), and only one HR gene (RAD51) remained significantly associated with survival in PDS and NACT groups, respectively. Conclusion Distinct HR expression profiles define subgroups associated with overall outcome in patients that are exposed to neoadjuvant chemotherapy and not only chemotherapy-naive patients.

Fanconi anemia (FA) is a genetically heterogeneous disorder with 22 disease-causing genes reported to date. In some FA genes, monoallelic mutations have been found to be associated with breast cancer risk, while the risk associations of others remain unknown. The gene for FA type C, FANCC, has been proposed as a breast cancer susceptibility gene based on epidemiological and sequencing studies. We used the Oncoarray project to genotype two truncating FANCC variants (p.R185X and p.R548X) in 64,760 breast cancer cases and 49,793 controls of European descent. FANCC mutations were observed in 25 cases (14 with p.R185X, 11 with p.R548X) and 26 controls (18 with p.R185X, 8 with p.R548X). There was no evidence of an association with the risk of breast cancer, neither overall (odds ratio 0.77, 95%CI 0.44–1.33, p = 0.4) nor by histology, hormone receptor status, age or family history. We conclude that the breast cancer risk association of these two FANCC variants, if any, is much smaller than for BRCA1, BRCA2 or PALB2 mutations. If this applies to all truncating variants in FANCC it would suggest there are differences between FA genes in their roles on breast cancer risk and demonstrates the merit of large consortia for clarifying risk associations of rare variants.

Background Fanconi anemia (FA) (OMIM #227650) is a rare hereditary disease characterized by genomic instability. The clinical phenotype involves malformations, bone marrow failure, and cancer predisposition. Genetic heterogeneity is a remarkable feature of FA; at least 22 FANC genes are known to cooperate in a unique FA/BRCA repair pathway. A common rule on the mutations found in these genes is allelic heterogeneity, except for mutations known to have arisen from a founder effect like the FANCC c.67delG in the Dutch Mennonite Community. Here, we present an 11‐year‐old male patient, member of the Mennonite Community of Tamaulipas México, with a clinical and cytogenetic diagnosis of FA. Method Chromosome fragility test was performed in all siblings. Genomic DNA was obtained from peripheral blood samples. Sanger sequencing was used to identify the FANCC c.67delG mutation (NC_000009.11(NM_000136.2):c.67delG p.(Asp23IlefsTer23)) and its accompanying haplotype. Results The FANCC c.67delG mutation in 13 members of his family confirmed a FA diagnosis in two of his siblings and identified heterozygous carriers. Haplotype analysis supports that in this family, FA is caused by the founder mutation that initially appeared in Mennonite Dutch and followed this population's migrations through Canada and further to Mexico. Conclusion The identification of the FANCC c.67delG mutation in this family not only allows proper genetic counseling, but it also grants the possibility to raise awareness of FA risk among the Mennonite community living in Mexico.

Fanconi anemia (FA) is a rare chromosomal instability syndrome with various clinical features and high cancer incidence. Despite being a DNA repair disorder syndrome and a frequently observed clinical hypersensitivity of FA patients towards ionizing radiation, the experimental evidence regarding the efficiency of radiation-induced DNA double-strand break (DSB) repair in FA is very controversial. Here, we performed a thorough analysis of the repair of radiation-induced DSBs in G1 and G2 in FA fibroblasts of complementation groups A, C, D1 (BRCA2), D2, E, F, G and P (SLX4) in comparison to normal human lung and skin fibroblasts. γH2AX, 53BP1, or RPA foci quantification after X-irradiation was combined with cell cycle markers. Cytogenetic analyses were performed on first metaphases after irradiation in G1 and by premature chromosome condensation after exposure in G2. Furthermore, the role of canonical-NHEJ and alternative-NHEJ for the fidelity of the repair of radiation-induced DSBs was examined. In FA fibroblasts, DSB repair was normal in G1 but compromised and more error-prone in the slow repair component of G2 as suggested by higher yields of radiation-induced γH2AX and 53BP1 foci as well as chromatid exchanges. However, RPA foci quantification in G2 indicated proficiency for homology-directed repair of DSBs in FA except for FA D1 (BRCA2). In lung fibroblasts, DSB repair in G1 was conducted with normal kinetics but elevated chromosome exchanges compared to skin fibroblasts. The overall repair of radiation-induced DSBs and the formation of chromosome exchanges in normal and FA fibroblasts in G1 and G2 were governed by canonical-NHEJ with no contribution of alternative-NHEJ. Together, we show impaired repair of radiation-induced DSBs in various FA complementation groups in the slow repair component of G2 that might promote the formation of potentially oncogenic aberrations and clinical radiation hypersensitivity.

Cancer risks in heterozygous mutation carriers of the ATM, BLM, and FANCC genes are controversial. To shed light on this issue, cancer rates were evaluated by cross referencing asymptomatic Israeli heterozygous mutation carriers in the ATM, BLM, and FANCC genes with cancer diagnoses registered at the Israeli National Cancer Registry (INCR). Comparison of observed to expected Standardized Incidence Rates (SIR) was performed. Overall, 474 individuals participated in the study: 378 females; 25 Arab and 31 Jewish ATM carriers, 152 BLM carriers, and 170 FANCC carriers (all Ashkenazim). Age range at genotyping was 19-53 years (mean + SD 30.6 + 5 years). In addition, 96 males were included; 5, 34, and 57 ATM, BLM, and FANCC mutation carriers, respectively. Over 5-16 years from genotyping (4721 person/years), 15 new cancers were diagnosed in mutation carriers: 5 breast, 4 cervical, 3 melanomas, and one each bone sarcoma, pancreatic, and colorectal cancer. No single cancer diagnosis was more prevalent then expected in all groups combined or per gene analyzed. Specifically breast cancer SIR was 0.02-0.77. We conclude that Israeli ATM, BLM, and FANCC heterozygous mutation carriers are not at an increased risk for developing cancer.

The Fanconi anemia DNA repair pathway is pivotal for the efficient repair of DNA interstrand cross-links. Here, we show that FA-defective (Fancc(-)) DT40 cells arrest in G(2) phase following cross-link damage and trigger apoptosis. Strikingly, cell death was reduced in Fancc(-) cells by additional deletion of the BRCA1 tumor suppressor, resulting in elevated clonogenic survival. Increased resistance to cross-link damage was not due to loss of toxic BRCA1-mediated homologous recombination but rather through the loss of a G(2) checkpoint. This proapoptotic role also required the BRCA1-A complex member ABRAXAS (FAM175A). Finally, we show that BRCA1 promotes G(2) arrest and cell death by prolonging phosphorylation of Chk1 on serine 345 after DNA damage to sustain arrest. Our data imply that DNA-induced cross-link death in cells defective in the FA pathway is dependent on the ability of BRCA1 to prolong cell cycle arrest in G(2) phase.

BACKGROUND Genetic assessment in Ashkenazi Jewish (AJ) patients often is limited to BRCA1/2 founder mutation testing. With access to time-efficient and cost-efficient multigene panel testing, some advocate expanding genetic testing in this population. However, to the best of the authors' knowledge, rates of nonfounder BRCA1/2 mutations and mutations in cancer-associated genes other than BRCA1/2 among AJ are not known. In the current study, the authors sought to assess the prevalence of mutations other than BRCA1/2 founder mutations among AJ patients undergoing genetic assessment. METHODS The authors reviewed the medical records for all AJ patients who underwent genetic assessment at a single institution between June 2013 and December 2016. Mutations were categorized as 1) BRCA1/2 AJ founder mutations (BRCA1 185delAG, BRCA1 5382insC, or BRCA2 6174delT); 2) nonfounder BRCA1/2 mutations; or 3) mutations in non-BRCA1/2 cancer-associated genes. RESULTS A total of 732 AJ patients underwent genetic assessment. Of these, 371 patients (51%) had a personal history of breast or ovarian cancer, 540 patients (73.8%) had a family history of breast cancer, and 132 patients (18%) had a family history of ovarian cancer. In the study population, 101 patients (13.8%) were found to have a pathogenic mutation, 78 patients (10.7%) had a BRCA1/2 founder mutation, 3 patients (0.4%) had a nonfounder BRCA1/2 mutation, and 20 patients (2.7%) had a mutation in a non-BRCA1/2 cancer-associated gene. Non-BRCA1/2 cancer-associated genes harboring mutations included RAD51D, TP53, mutS homolog 6 (MSH6), checkpoint kinase 2 (CHEK2), adenomatous polyposis coli (APC), and Fanconi anemia group C protein (FANCC). CONCLUSIONS Among AJ patients found to have a pathogenic mutation on genetic assessment, approximately 22.8% had a mutation that would be missed with BRCA1/2 AJ founder mutation testing. Comprehensive multigene panel sequencing can provide clinically relevant genetic information for AJ patients and should be considered for genetic assessment in this population.

Diabetes mellitus (DM) and other glucose metabolism abnormalities are commonly observed in individuals with Fanconi anemia (FA). FA causes an impaired response to DNA damage due to genetic defects in a cluster of genes encoded proteins involved in DNA repair. However, the mechanism by which FA is associated with DM has not been clearly elucidated. Fanconi anemia complementation group C (FANCC) is a component of FA nuclear clusters. Evidence suggests that cytoplasmic FANCC has a role in protection against oxidative stress‑induced apoptosis. As oxidative stress‑mediated β‑cell dysfunction is one of the contributors to DM pathogenesis, the present study aimed to investigate the role of FANCC in pancreatic β‑cell response to oxidative stress. Small interfering RNA‑mediated FANCC suppression caused a loss of protection against oxidative stress‑induced apoptosis, and that overexpression of FANCC reduced this effect in the human 1.1B4 β‑cell line. These findings were confirmed by Annexin V‑FITC/PI staining, caspase 3/7 activity assay, and expression levels of anti‑apoptotic and pro‑apoptotic genes. Insulin and glucokinase mRNA expression were also decreased in FANCC‑depleted 1.1B4 cells. The present study demonstrated the role of FANCC in protection against oxidative stress‑induced β‑cell apoptosis and established another mechanism that associates FANCC deficiency with β‑cell dysfunction. The finding that FANCC overexpression reduced β‑cell apoptosis advances the potential for an alternative approach to the treatment of DM caused by FANCC defects.

Defects in DNA repair can cause various genetic diseases with severe pathological phenotypes. Fanconi anemia (FA) is a rare disease characterized by bone marrow failure, developmental abnormalities, and increased cancer risk that is caused by defective repair of DNA interstrand crosslinks (ICLs). Here, we identify the deubiquitylating enzyme USP48 as synthetic viable for FA-gene deficiencies by performing genome-wide loss-of-function screens across a panel of human haploid isogenic FA-defective cells (FANCA, FANCC, FANCG, FANCI, FANCD2). Thus, as compared to FA-defective cells alone, FA-deficient cells additionally lacking USP48 are less sensitive to genotoxic stress induced by ICL agents and display enhanced, BRCA1-dependent, clearance of DNA damage. Consequently, USP48 inactivation reduces chromosomal instability of FA-defective cells. Our results highlight a role for USP48 in controlling DNA repair and suggest it as a potential target that could be therapeutically exploited for FA., Fanconi anemia is a rare disease caused by defective DNA interstrand crosslink repair. Here the authors observe that USP48 deficiencies reduce chromosomal instability in FA-defective cells, suggesting it might be a potential therapeutic target.

Fanconi anemia (FA) is a rare recessive disease characterized by progressive bone marrow failure, congenital abnormalities, and increased incidence of cancers. To date, mutations in 22 genes can cause FA or an FA-like phenotype. In China, in addition to clinical information, FA diagnosis primarily relies on genetic sequencing because the chromosome breakage test is rarely performed. Here, we employed multiple genetic diagnostic tools (DNA sequencing, multiplex ligation-dependent probe amplification, and chromosome microarray) and a variant-based functional assay platform to investigate the genetic cause in 25 Chinese suspected FA patients. A total of 45 distinct candidate variants were detected in six FA genes (FA-A, FA-B, FA-C, FA-D2, FA-G, and FA-J), of which 36 were novel. Eight missense variants and one indel variant were unable to restore FANCD2 mono-ubiquitination and mitomycin C resistance in a panel of FA indicator cell lines, indicating that these mutations are deleterious. Three missense variants (FANCA-L424V, FANCC-E273K, and FANCG-A153G) were harmless. Finally, 23 patients were molecularly diagnosed with FA, consistent with their clinical phenotype. In the FA-A subgroup, large deletions accounted for 14% of the disease-causing variants. We have established a comprehensive molecular diagnostic workflow for Chinese FA patients that can substitute for standard FA cytogenetic analysis.

Given importance of 22-Fanconi Anemia (FA) proteins together to act in a signaling pathway in preventing deleterious clinical symptoms, e.g. severe bone marrow failure, congenital defects, an early onset of aging and cancer, studies on each FA protein become increasingly attractive. However, an unbiased and systematic investigation of cellular effects resulting from each FA protein is missing. Here, we report roles of FA complementation C group protein (FANCC) in the protection from metabolic disorders. This study was prompted by the diabetes-prone feature displayed in FANCC knockout mice, which is not typically shown in patients with FA. We found that in cells expressing FANCC at different levels, there are representative alterations in metabolites associated with aging (glycine, citrulline, ornithine, L-asparagine, L-tyrosine, L-arginine, L-glutamine, L-leucine, L-isoleucine, L-valine, L-proline and L-alanine), Diabetes Mellitus (DM) (carbon monoxide, collagens, fatty acids, D-glucose, fumaric acid, 2-oxoglutaric acid, C3), inflammation (inosine, L-arginine, L-isoleucine, L-leucine, L-lysine, L-phenylalanine, hypoxanthine, L-methionine), and cancer ( L-methionine, sphingomyelin, acetyl-L-carnitine, L-aspartic acid, L-glutamic acid, niacinamide, phospho-rylethanolamine). We also found that FANCC can act in an FA-pathway-independent manner in tumor suppression. Collectively, featured-metabolic alterations are readouts of functional mechanisms underlying reduced tumorigenicity driven by FANCC, demonstrating close links among cancer, aging, inflammation and DM.

Introduction: Leptin is a hormone secreted by adipocytes that has been associated with the epithelial-mesenchymal transition (EMT). Additionally, leptin promotes the migration and invasion of mammary epithelial cells through the activation of FAK and Src kinases, which are part of a regulatory complex of signaling pathways that promotes the expression of proteins related to the formation of proteolytic structures involved in the invasion and progression of cancer. Recently, overexpression and activation of Hic-5 during the EMT have been shown to induce the formation of actin puncta; these structures are indicative of the formation and functionality of invadopodia, which promote the local degradation of extracellular matrix components and cancer metastasis. Objective: To evaluate the role of FAK and Src kinases in the expression of Hic-5 during the epithelial-mesenchymal transition induced by leptin in MCF10A cells. Materials and methods: We used specific inhibitors of FAK (PF-573228) and Src (PP2) to evaluate Hic-5 expression and subcellular localization by Western blot and immunofluorescence assays and to investigate the formation of actin puncta by epifluorescence in MCF10A cells stimulated with leptin. Results: Leptin induced an increase in Hic-5 expression and the formation of actin puncta. Pretreatment with inhibitors of FAK (PF-573228) and Src (PP2) promoted a decrease in Hic-5 expression and actin puncta formation in the non-tumorigenic mammary epithelial cell line MCF10A. Conclusion: In MCF10A cells, leptin-induced Hic-5 expression and perinuclear localization, as well as the formation of actin puncta through a mechanism dependent on the kinase activity of FAK and Src.Introducción. La leptina es una hormona secretada por los adipocitos que se ha relacionado con el proceso de la transición de epitelio a mesénquima (Epithelial-Mesenchymal Transition, EMT). Promueve la migración e invasión de las células del epitelio mamario mediante la activación de las cinasas FAK y Src, un complejo regulador de vías de señalización que favorecen la expresión de las proteínas relacionadas con la formación de estructuras proteolíticas implicadas en la invasión y progresión del cáncer. Recientemente, se ha descrito que la sobreexpresión y activación de la proteína Hic-5 durante el mencionado proceso de transición, favorece la formación de los puntos de actina (indicativa de la formación y funcionalidad de los invadopodios), lo cual promueve la degradación local de los componentes de la matriz extracelular y la metástasis del cáncer. Objetivos. Evaluar el papel de las cinasas FAK y Src sobre la expresión y localización subcelular de Hic-5 y la formación de puntos de actina inducida por la leptina en la línea celular MCF10A de epitelio mamario no tumoral. Materiales y métodos. Se utilizaron los inhibidores específicos de la FAK (PF-573228) y la Src (PP2) para evaluar el papel de ambas cinasas en los niveles de expresión y localización subcelular de la proteína Hic-5 mediante Western blot e inmunofluorescencia, así como la formación de puntos de actina mediante la tinción con faloidina-TRITC en células MCF10A estimuladas con leptina. Resultados. La leptina indujo el incremento en la expresión de Hic-5 y la formación de puntos de actina. El tratamiento previo con los inhibidores de las cinasas FAK (PF-573228) y Src (PP2), promovió la disminución en la expresión de Hic-5 y de los puntos de actina en la línea celular MCF10A de epitelio mamario no tumoral. Conclusión. La leptina indujo la expresión y la localización perinuclear de Hic-5 y la formación de puntos de actina mediante un mecanismo dependiente de la actividad de las cinasas FAK y Src en las células MCF10A.

Genome-wide association studies (GWAS) have identified genetic variants in a number of chromosomal regions that are associated with atrial fibrillation (AF). The mechanisms underlying these associations are unknown, but are likely to involve effects of the risk haplotypes on expression of neighbouring genes. To investigate the association between genetic variants at AF-associated loci and expression of nearby candidate genes in human atrial tissue and peripheral blood. Right atrial appendage (RAA) samples were collected from 122 patients undergoing cardiac surgery, of these, 12 patients also had left atrial appendage samples taken. 22 patients had a history of AF. Peripheral blood samples were collected from 405 patients undergoing diagnostic cardiac catheterisation. In order to tag genetic variation at each of nine loci, a total of 367 single nucleotide polymorphisms (SNPs) were genotyped using the Sequenom platform. Total expression of 16 candidate genes in the nine AF-associated regions was measured by quantitative PCR. The relative expression of each allele of the candidate genes was measured on the Sequenom platform using one or more transcribed SNPs to distinguish between alleles in heterozygotes. We tested association between the SNPs of interest and gene expression using total gene expression (integrating cis and trans acting sources of variation), and allelic expression ratios (specific for cis acting influences), in atrial tissue and peripheral blood. We adjusted for multiple comparisons using a Bonferroni approach. In subsidiary analyses, we compared the expression of candidate genes between patients with and without a history of AF. Total expression of 15 transcripts of 14 genes and allelic expression ratio of 14 transcripts of 14 genes in genomic regions associated with AF were measured in right atrial appendage tissue. 8 of these transcripts were also expressed in peripheral blood. Risk alleles at AF-associated SNPs were associated in cis with an increased expression of PITX2a (2.01-fold, p=6.5×10(-4)); and with decreased expression of MYOZ1 (0.39 fold; p=5.5×10(-15)), CAV1 (0.89 fold; p=5.9×10(-8)), C9orf3 (0.91 fold; 1.5×10(-5)), and FANCC (0.94-fold; p=8.9×10(-8)) in right atrial appendage. Of these five genes, only CAV1 was expressed in peripheral blood; association between the same AF risk alleles and lower expression of CAV1 was confirmed (0.91 fold decrease; p=4.2×10(-5)). A history of AF was also associated with a decrease in expression of CAV1 in both right and left atria (0.84 and 0.85 fold, respectively; p=0.03), congruent with the magnitude of the effect of the risk SNP on expression, and independent of genotype. The analyses in peripheral blood showed association between AF risk SNPs and decreased expression of KCNN3 (0.85-fold; p=2.1×10(-4)); and increased expression of SYNE2 (1.12-fold; p=7.5×10(-24)); however, these associations were not detectable in atrial tissue. We identified novel cis-acting associations in atrial tissue between AF risk SNPs and increased expression of PITX2a/b; and decreased expression of CAV1 (an association also seen in peripheral blood), C9orf3 and FANCC. We also confirmed a previously described association between AF risk variants and MYOZ1 expression. Analyses of peripheral blood illustrated tissue-specificity of cardiac eQTLs and highlight the need for larger-scale genome-wide eQTL studies in cardiac tissue. Our results suggest novel aetiological roles for genes in four AF-associated genomic regions.

Aims: This study seeks at investigating the cause of hydrocephalus, and at identifying therapeutic targets for the prevention of hydrocephalus. Results: In this study, we show that inactivation of the Foxo3a gene in two mouse models of Fanconi anemia (FA) leads to the development of hydrocephalus in late embryonic stage and after birth. More than 50% of Foxo3a−/− Fancc−/− or Foxo3a−/− Fancd2−/− mice die during embryonic development or within 6 months of life as a result of hydrocephalus characterized by cranial distortion, dilation of the ventricular system, reduced thickness of the cerebral cortex, and disorganization of the ependymal cilia and subcommissural organ. Combined deficiency of Foxo3a and Fancc or Fancd2 not only impairs the self-renewal capacity but also markedly increases the apoptosis of neural stem and progenitor cells (NSPCs), leading to defective neurogenesis. Increased accumulation of reactive oxygen species (ROS) and subsequently de-regulated mitosis and ultimately apoptosis in the neural stem or progenitor cells is identified as one of the potential mechanisms of congenital obstructive hydrocephalus. Innovation: The work unravels a two-tier protective mechanism for preventing oxidative stress-induced hydrocephalus. Conclusion: The deletion of Foxo3a in FA mice increased the accumulation of ROS and subsequently de-regulated mitosis and ultimately apoptosis in the NSPCs, leading to hydrocephalus development. Antioxid. Redox Signal. 21, 1675–1692.

Previous Fanconi anemia (FA) gene therapy studies have failed to demonstrate engraftment of gene-corrected hematopoietic stem and progenitor cells (HSPCs) from FA patients, either after autologous transplantation or infusion into immunodeficient mice. In this study, we demonstrate that a validated short transduction protocol of G-CSF plus plerixafor-mobilized CD34

Fanconi anemia is a complex heterogeneous genetic disorder with a high incidence of bone marrow failure, clonal evolution to acute myeloid leukemia and mesenchymal-derived congenital anomalies. Increasing evidence in Fanconi anemia and other genetic disorders points towards an interdependence of skeletal and hematopoietic development, yet the impact of the marrow microenvironment in the pathogenesis of the bone marrow failure in Fanconi anemia remains unclear. Here we demonstrated that mice with double knockout of both Fancc and Fancg genes had decreased bone formation at least partially due to impaired osteoblast differentiation from mesenchymal stem/progenitor cells. Mesenchymal stem/progenitor cells from the double knockout mice showed impaired hematopoietic supportive activity. Mesenchymal stem/progenitor cells of patients with Fanconi anemia exhibited similar cellular deficits, including increased senescence, reduced proliferation, impaired osteoblast differentiation and defective hematopoietic stem/progenitor cell supportive activity. Collectively, these studies provide unique insights into the physiological significance of mesenchymal stem/progenitor cells in supporting the marrow microenvironment, which is potentially of broad relevance in hematopoietic stem cell transplantation.

Accumulating evidence suggests that dormant DNA replication origins play an important role in the recovery of stalled forks. However, their functional interactions with other fork recovery mechanisms have not been tested. We previously reported intrinsic activation of the Fanconi anemia (FA) pathway in a tumor-prone mouse model (Mcm4chaos3) with a 60% loss of dormant origins. To understand this further, we introduced a null allele of Fancc (Fancc−), encoding a member of the FA core complex, into the Mcm4chaos3 background. Primary embryonic fibroblasts double homozygous for Mcm4chaos3 and Fancc− (Mcm4chaos3/chaos3;Fancc−/−) showed significantly increased levels of markers of stalled/collapsed forks compared to either single homozygote. Interestingly, a loss of dormant origins also increased the number of sites in which replication was delayed until prophase, regardless of FA pathway activation. These replication defects coincided with substantially elevated levels of genome instability in Mcm4chaos3/chaos3;Fancc−/− cells, resulting in a high rate of perinatal lethality of Mcm4chaos3/chaos3;Fancc−/− mice and the accelerated tumorigenesis of surviving mice. Together, these findings uncover a specialized role of dormant origins in replication completion while also identifying important functional overlaps between dormant origins and the FA pathway in maintaining fork progression, genome stability, normal development and tumor suppression.

Fanconi anemia (FA) is an inherited bone marrow failure syndrome associated with a progressive decline in hematopoietic stem cells, developmental defects, and predisposition to cancer. These various phenotypic features imply a role of FA proteins in molecular events regulating cellular homeostasis. Interestingly, we previously found that the Fanconi C protein (FANCC) interacts with the C-terminal-binding protein-1 (CtBP1) involved in transcriptional regulation. Here we report that FANCC with CtBP1 forms a complex with β-catenin, and that β-catenin activation through glycogen synthase kinase 3β inhibition leads to FANCC nuclear accumulation and FA pathway activation, as measured by the Fanconi D2 protein (FANCD2) monoubiquitination. β-catenin and FANCC nuclear entry is defective in FA mutant cells and in cells depleted of the Fanconi A protein or FANCD2, suggesting that integrity of the FA pathway is required for FANCC nuclear activity. We also report that FANCC with CtBP1 acts as a negative regulator of Dickkopf-1 (DKK1) expression, and that a FA disease-causing mutation in FANCC abrogates this function. Our findings reveal that a defective FA pathway leads to up-regulation of DKK1, a molecule involved in hematopoietic malignancies.

Familial pancreatic cancer (FPC) includes those kindreds that contain at least two first degree relatives with pancreatic ductal adenocarcinoma. At least twelve known hereditary syndromes or genes are associated with increased risk of developing pancreatic cancer, the foremost being BRCA2 and CDKN2A. Research into the identification of mutations in known cancer predisposition genes and through next generation sequencing has revealed extensive heterogeneity. The development of genetic panel testing has enabled genetic risk assessment and predisposition testing to be routinely offered. Precision oncology has opened the possibility of “incidental” germline mutations that may have implications for family members. However, in both cases, evidence-based recommendations for managing patients and at-risk family members in light of genetic status remain emergent, with current practice based upon expert opinion.

Hematopoietic stem and progenitor cells with inactivated Fanconi anemia (FA) genes, FANCA and FANCC, are hypersensitive to inflammatory cytokines. One of these, tumor necrosis factor α (TNF-α), is also overproduced by FA mononuclear phagocytes in response to certain Toll-like receptor (TLR) agonists, creating an autoinhibitory loop that may contribute to the pathogenesis of progressive bone marrow (BM) failure and selection of TNF-α-resistant leukemic stem cell clones. In macrophages, the TNF-α overproduction phenotype depends on p38 mitogen-activated protein kinase (MAPK), an enzyme also known to induce expression of other inflammatory cytokines, including interleukin 1β (IL-1β). Reasoning that IL-1β might be involved in a like autoinhibitory loop, we determined that (1) TLR activation of FANCA- and FANCC-deficient macrophages induced overproduction of both TNF-α and IL-1β in a p38-dependent manner; (2) exposure of Fancc-deficient BM progenitors to IL-1β potently suppressed the expansion of multipotent progenitor cells in vitro; and (3) although TNF-α overexpression in FA cells is controlled posttranscriptionally by the p38 substrate MAPKAPK-2, p38-dependent overproduction of IL-1β is controlled transcriptionally. We suggest that multiple inflammatory cytokines overproduced by FANCA- and FANCC-deficient mononuclear phagocytes may contribute to the progressive BM failure that characterizes FA, and that to achieve suppression of this proinflammatory state, p38 is a more promising molecular therapeutic target than either IL-1β or TNF-α alone.

Gorlin syndrome or nevoid basal cell carcinoma syndrome (NBCCS) is an autosomal dominant condition mainly characterized by the development of mandibular keratocysts which often have their onset during the second decade of life and/or multiple basal cell carcinoma (BCC) normally arising during the third decade. Cardiac and ovarian fibromas can be found. Patients with NBCCS develop the childhood brain malignancy medulloblastoma (now often called primitive neuro-ectodermal tumor [PNET]) in 5% of cases. The risk of other malignant neoplasms is not clearly increased, although lymphoma and meningioma can occur in this condition. Wilms tumor has been mentioned in the literature four times. We describe a patient with a 10.9 Mb 9q22.3 deletion spanning 9q22.2 through 9q31.1 that includes the entire codifying sequence of the gene PTCH1, with Wilms tumor, multiple neoplasms (lung, liver, mesenteric, gastric and renal leiomyomas, lung typical carcinoid tumor, adenomatoid tumor of the pleura) and a severe clinical presentation. We propose including leiomyomas among minor criteria of the NBCCS. © 2013 Wiley Periodicals, Inc.

HELQ is a superfamily 2 DNA helicase found in archaea and metazoans. It has been implicated in processing stalled replication forks and in repairing DNA double-strand breaks and inter-strand crosslinks. Though previous studies have suggested the possibility that HELQ is involved in the Fanconi anemia (FA) pathway, a dominant mechanism for inter-strand crosslink repair in vertebrates, this connection remains elusive. Here, we investigated this question in mice using the Helqgt and Fancc− strains. Compared with Fancc−/− mice lacking FANCC, a component of the FA core complex, Helqgt/gt mice exhibited a mild of form of FA-like phenotypes including hypogonadism and cellular sensitivity to the crosslinker mitomycin C. However, unlike Fancc−/− primary fibroblasts, Helqgt/gt cells had intact FANCD2 mono-ubiquitination and focus formation. Notably, for all traits examined, Helq was non-epistatic with Fancc, as Helqgt/gt;Fancc−/− double mutants displayed significantly worsened phenotypes than either single mutant. Importantly, this was most noticeable for the suppression of spontaneous chromosome instability such as micronuclei and 53BP1 nuclear bodies, known consequences of persistently stalled replication forks. These findings suggest that mammalian HELQ contributes to genome stability in unchallenged conditions through a mechanism distinct from the function of FANCC.

Current methods for detecting mutations in Fanconi anemia (FA)-suspected patients are inefficient and often miss mutations. We have applied recent advances in DNA sequencing and genomic capture to the diagnosis of FA. Specifically, we used custom molecular inversion probes or TruSeq-enrichment oligos to capture and sequence FA and related genes, including introns, from 27 samples from the International Fanconi Anemia Registry at The Rockefeller University. DNA sequencing was complemented with custom array comparative genomic hybridization (aCGH) and RNA sequencing (RNA-seq) analysis. aCGH identified deletions/duplications in 4 different FA genes. RNA-seq analysis revealed lack of allele specific expression associated with a deletion and splicing defects caused by missense, synonymous, and deep-in-intron variants. The combination of TruSeq-targeted capture, aCGH, and RNA-seq enabled us to identify the complementation group and biallelic germline mutations in all 27 families: FANCA (7), FANCB (3), FANCC (3), FANCD1 (1), FANCD2 (3), FANCF (2), FANCG (2), FANCI (1), FANCJ (2), and FANCL (3). FANCC mutations are often the cause of FA in patients of Ashkenazi Jewish (AJ) ancestry, and we identified 2 novel FANCC mutations in 2 patients of AJ ancestry. We describe here a strategy for efficient molecular diagnosis of FA.

Aims: Insulin resistance is a hallmark of obesity and type 2 diabetes. Reactive oxygen species (ROS) have been proposed to play a causal role in insulin resistance. However, evidence linking ROS to insulin resistance in disease settings has been scant. Since both oxidative stress and diabetes have been observed in patients with the Fanconi anemia (FA), we sought to investigate the link between ROS and insulin resistance in this unique disease model. Results: Mice deficient for the Fanconi anemia complementation group A (Fanca) or Fanconi anemia complementation group C (Fancc) gene seem to be diabetes-prone, as manifested by significant hyperglycemia and hyperinsulinemia, and rapid weight gain when fed with a high-fat diet. These phenotypic features of insulin resistance are characterized by two critical events in insulin signaling: a reduction in tyrosine phosphorylation of the insulin receptor (IR) and an increase in inhibitory serine phosphorylation of the IR substrate-1 in the liver, muscle, and fat tissues from the insulin-challenged FA mice. High levels of ROS, spontaneously accumulated or generated by tumor necrosis factor alpha in these insulin-sensitive tissues of FA mice, were shown to underlie the FA insulin resistance. Treatment of FA mice with the natural anti-oxidant Quercetin restores IR signaling and ameliorates the diabetes- and obesity-prone phenotypes. Finally, pairwise screen identifies protein-tyrosine phosphatase (PTP)-α and stress kinase double-stranded RNA-dependent protein kinase (PKR) that mediate the ROS effect on FA insulin resistance. Innovation: These findings establish a pathogenic and mechanistic link between ROS and insulin resistance in a unique human disease setting. Conclusion: ROS accumulation contributes to the insulin resistance in FA deficiency by targeting both PTP-α and PKR. Antioxid. Redox Signal. 00, 000–000.

Pancreatic cancer is now the third leading cause of cancer related deaths in the United States, yet advances in treatment options have been minimal over the past decade. In this review, we summarize the evaluation and treatments for this disease. We highlight molecular advances that hopefully will soon translate into improved outcomes.

A case of invasive, keratinizing squamous cell carcinoma of the larynx in an 8-year-old female treated with laryngectomy is presented. Perinatal exposure to human papilloma virus and constitutional heterozygosity for a FANCC mutation were identified, though FANCC heterozygosity is not known to be cancer predisposing. An additional tumor-associated mutation in NOTCH1 was also identified potentially contributing to oncogenesis. This case illustrates an exceedingly rare type of cancer in the pediatric population and discusses diagnostic workup, evaluation of risk factors for head and neck cancer, and treatment options.

Fanconi anemia (FA) is an inherited disorder of genomic instability associated with high risk of myelodysplasia and acute myeloid leukemia (AML). Young mice deficient in FA core complex genes do not naturally develop cancer, hampering preclinical studies on malignant hematopoiesis in FA. Here we describe that aging Fancc −/− mice are prone to genomically unstable AML and other hematologic neoplasms. We report that aneuploidy precedes malignant transformation during Fancc −/− hematopoiesis. Our observations reveal that Fancc −/− mice develop hematopoietic chromosomal instability followed by leukemia in an age-dependent manner, recapitulating the clinical phenotype of human FA and providing a proof of concept for future development of preclinical models of FA-associated leukemogenesis.

Background Carcinogens in cigarette smoke can induce the formation of DNA-DNA cross-links, which are repaired by the Fanconi anemia (FA) pathway, and it is tempting to speculate that this pathway is involved in lung tumorigenesis. This study is to determine whether genetic polymorphism of the FA genes is associated with an elevated risk of lung adenocarcinoma, and whether the association between genotypes and risk is modified by exposure to cigarette smoke. Methods This case–control study genotyped 53 single-nucleotide polymorphisms (SNPs) in FA genes in 709 patients (354 males and 355 females) with lung adenocarcinoma and in 726 cancer-free individuals (339 males and 387 females). Genotypic frequencies of SNPs were compared between cases and controls to identify important FA genes associated with cancer susceptibility. Joint effects in determining cancer risk contributed by genes and smoking-related risk factors and by multiple genes involved in different FA subpathways were evaluated by multivariate regression analysis and stratified analysis. All analyses were performed on males and females separately, and the comparison of results was considered a way of examining the validity of study findings. Results Lung adenocarcinomas in both male and female patients were associated with (a) genotypic polymorphisms of FANCC and FANCD1; (b) a combined effect of harboring a higher number of high-risk genotypes and smoking/passive smoking; (c) specific interactions of multiple genes, proteins encoded by which have been known to work jointly within the FA pathway. Conclusions Genetic polymorphism of the FA genes is associated with inter-individual susceptibility to lung adenocarcinoma. Electronic supplementary material The online version of this article (doi:10.1186/s12929-016-0240-9) contains supplementary material, which is available to authorized users.

Colorectal cancer (CRC) is one of the most common neoplasms in the world. Fanconi anemia (FA) is a very rare genetic disease causing bone marrow failure, congenital growth abnormalities and cancer predisposition. The comprehensive FA DNA damage repair pathway requires the collaboration of 53 proteins and it is necessary to restore genome integrity by efficiently repairing damaged DNA. A link between FA genes in breast and ovarian cancer germline predisposition has been previously suggested. We selected 74 CRC patients from 40 unrelated Spanish families with strong CRC aggregation compatible with an autosomal dominant pattern of inheritance and without mutations in known hereditary CRC genes and performed germline DNA whole-exome sequencing with the aim of finding new candidate germline predisposition variants. After sequencing and data analysis, variant prioritization selected only those very rare alterations, producing a putative loss of function and located in genes with a role compatible with cancer. We detected an enrichment for variants in FA DNA damage repair pathway genes in our familial CRC cohort as 6 families carried heterozygous, rare, potentially pathogenic variants located in BRCA2/FANCD1, BRIP1/FANCJ, FANCC, FANCE and REV3L/POLZ. In conclusion, the FA DNA damage repair pathway may play an important role in the inherited predisposition to CRC.

Bone marrow failure is a nearly universal complication of Fanconi anemia. The proteins encoded by FANC genes are involved in DNA damage responses through the formation of a multisubunit nuclear complex that facilitates the E3 ubiquitin ligase activity of FANCL. However, it is not known whether loss of E3 ubiquitin ligase activity accounts for the hematopoietic stem cell defects characteristic of Fanconi anemia. Here we provide evidence that FANCL increases the activity and expression of β-catenin, a key pluripotency factor in hematopoietic stem cells. We show that FANCL ubiquitinates β-catenin with atypical ubiquitin chain extension known to have nonproteolytic functions. Specifically, β-catenin modified with lysine-11 ubiquitin chain extension efficiently activates a lymphocyte enhancer-binding factor-T cell factor reporter. We also show that FANCL-deficient cells display diminished capacity to activate β-catenin leading to reduced transcription of Wnt-responsive targets c-Myc and Cyclin D1. Suppression of FANCL expression in normal human CD34+ stem and progenitor cells results in fewer β-catenin active cells and inhibits expansion of multilineage progenitors. Together, these results suggest that diminished Wnt/β-catenin signaling may be an underlying molecular defect in FANCL-deficient hematopoietic stem cells leading to their accelerated loss.

Summary Fanconi anemia (FA) is an inherited DNA repair deficiency syndrome. FA patients undergo progressive bone marrow failure (BMF) during childhood, which frequently requires allogeneic hematopoietic stem cell transplantation. The pathogenesis of this BMF has been elusive to date. Here we found that FA patients exhibit a profound defect in hematopoietic stem and progenitor cells (HSPCs) that is present before the onset of clinical BMF. In response to replicative stress and unresolved DNA damage, p53 is hyperactivated in FA cells and triggers a late p21 Cdkn1a -dependent G0/G1 cell-cycle arrest. Knockdown of p53 rescued the HSPC defects observed in several in vitro and in vivo models, including human FA or FA-like cells. Taken together, our results identify an exacerbated p53/p21 "physiological" response to cellular stress and DNA damage accumulation as a central mechanism for progressive HSPC elimination in FA patients, and have implications for clinical care.

The Fanconi anemia proteins participate in a canonical pathway that repairs cross-linking agent-induced DNA damage. Cells with inactivated Fanconi anemia genes are universally hypersensitive to such agents. Fanconi anemia-deficient hematopoietic stem cells are also hypersensitive to inflammatory cytokines, and, as importantly, Fanconi anemia macrophages overproduce such cytokines in response to TLR4 and TLR7/8 agonists. We questioned whether TLR-induced DNA damage is the primary cause of aberrantly regulated cytokine production in Fanconi anemia macrophages by quantifying TLR agonist-induced TNF-α production, DNA strand breaks, crosslinker-induced chromosomal breakage, and Fanconi anemia core complex function in Fanconi anemia complementation group C-deficient human and murine macrophages. Although both M1 and M2 polarized Fanconi anemia cells were predictably hypersensitive to mitomycin C, only M1 macrophages overproduced TNF-α in response to TLR-activating signals. DNA damaging agents alone did not induce TNF-α production in the absence of TLR agonists in wild-type or Fanconi anemia macrophages, and mitomycin C did not enhance TLR responses in either normal or Fanconi anemia cells. TLR4 and TLR7/8 activation induced cytokine overproduction in Fanconi anemia macrophages. Also, although TLR4 activation was associated with induced double strand breaks, TLR7/8 activation was not. That DNA strand breaks and chromosome breaks are neither necessary nor sufficient to account for the overproduction of inflammatory cytokines by Fanconi anemia cells suggests that noncanonical anti-inflammatory functions of Fanconi anemia complementation group C contribute to the aberrant macrophage phenotype and suggests that suppression of macrophage/TLR hyperreactivity might prevent cytokine-induced stem cell attrition in Fanconi anemia.

FA is a genetic disorder characterized by BM failure, developmental defects, and cancer predisposition. Previous studies suggest that FA patients exhibit alterations in immunologic function. However, it is unclear whether the defects are immune cell-autonomous or secondary to leukopenia from evolving BM failure. Given the central role that macrophages have in the innate immune response, inflammation resolution, and antigen presentation for acquired immunity, we examined whether macrophages from Fancc−/− mice exhibit impaired function. Peritoneal inflammation induced by LPS or sodium periodate resulted in reduced monocyte/macrophage recruitment in Fancc−/− mice compared with WT controls. Fancc−/− mice also had decreased inflammatory monocytes mobilized into the peripheral blood after LPS treatment compared with controls. Furthermore, Fancc−/− peritoneal macrophages displayed cell-autonomous defects in function, including impaired adhesion to FN or endothelial cells, reduced chemoattractant-mediated migration, and decreased phagocytosis. Moreover, dysregulated F-actin rearrangement was detected in Fancc−/− macrophages after adhesion to FN, which was consistent with an observed reduction in RhoA-GTP levels. Importantly, these data suggest that impaired cytoskeletal rearrangements in Fancc−/− macrophages may be the common mechanism responsible for cell-autonomous defects detected in vitro, as well as altered monocyte/macrophage trafficking in vivo.

Objective Disrupting the function of any of the 13 Fanconi anaemia (FA) genes causes a DNA repair deficiency disorder, with patients being susceptible to a number of cancer types. Variation in the family of FA genes has been suggested to affect risk of cervical cancer. The current study evaluates the influence of three genes in the FA pathway on cervical cancer risk in Swedish women. Methods TagSNPs in FANCA, FANCC and FANCL were selected using the Tagger algorithm in Haploview. A total of 81 tagSNPs were genotyped in 782 cases (CIN3 or ICC) and 775 controls using the Illumina GoldenGate Assay and statistically analyzed for association with cervical cancer. Results 72 SNPs were successfully genotyped in >98% of the samples. Nominal associations were detected for FANCA rs11649196 ( p =0.05) and rs4128763 in FANCC ( p =0.02). The associations did not withstand correction for multiple testing. Conclusions The current study does not support that genetic variation in FANCA, FANCC or FANCL genes affects susceptibility to cervical cancer in the Swedish population.