Involvement of FANCD2 in Energy Metabolism via ATP5α

Somatic gene mutations involved in DNA damage response/Fanconi anemia signaling are tissue- and cell-type specific in human solid tumors

With significant advancements in the study of DNA Damage Response (DDR) and Fanconi Anemia (FA) signaling, we previously introduced the term "FA signaling" to encompass "all signaling transductions involving one or more FA proteins." This network has now evolved into the largest cellular defense network, integrating over 30 key players, including ATM, ATR, BLM, HRR6, RAD18, FANCA, FANCB, FANCC, BRCA2, FANCD2, FANCE, FANCF, FANCG, FANCI, BRIP1, FANCL, FANCM, PALB2, RAD51C, SLX4, ERCC4, RAD51, BRCA1, UBE2T, XRCC2, MAD2L2, RFWD3, FAAP20, FAAP24, FAAP100, and CENPX. This system responds to both endogenous and exogenous cellular insults. However, the mutational signatures associated with this defense mechanism in non-FA human cancers have not been extensively explored. In this study, we report that different types of human cancers are characterized by distinct somatically mutated genes related to DDR/FA signaling, each accompanied by a unique spectrum of potential driver mutations. For example, in pan-cancer samples, ATM emerges as the most frequently mutated gene (5%) among the 31 genes analyzed, with the highest number of potential driver mutations (1714), followed by BRCA2 (4% with 970 putative driver mutations). However, this pattern is not universal across specific cancer types. For example, FANCT is the most frequently mutated gene in breast (14%) and liver (4%) cancers. In addition, the alteration frequency of DDR/FA signaling due to these mutations exceeds 70% in a subtype of prostate cancer, with each subtype of brain, breast, lung, and prostate cancers displaying distinct patterns of gene alteration frequency. Furthermore, these gene alteration patterns significantly impact patient survival and disease-free periods. Collectively, our findings not only enhance our understanding of cancer development and progression but also have significant implications for cancer patient care and prognosis, particularly in the development of effective therapeutic strategies.

Research progress of the Fanconi anemia pathway and premature ovarian insufficiency†

The Fanconi anemia pathway is a key pathway involved in the repair of deoxyribonucleic acidinterstrand crosslinking damage, which chiefly includes the following four modules: lesion recognition, Fanconi anemia core complex recruitment, FANCD2-FANCI complex monoubiquitination, and downstream events (nucleolytic incision, translesion synthesis, and homologous recombination). Mutations or deletions of multiple Fanconi anemia genes in this pathway can damage the interstrand crosslinking repair pathway and disrupt primordial germ cell development and oocyte meiosis, thereby leading to abnormal follicular development. Premature ovarian insufficiency is a gynecological clinical syndrome characterized by amenorrhea and decreased fertility due to decreased oocyte pool, accelerated follicle atresia, and loss of ovarian function in women <40 years old. Furthermore, in recent years, several studies have detected mutations in the Fanconi anemia gene in patients with premature ovarian insufficiency. In addition, some patients with Fanconi anemia exhibit symptoms of premature ovarian insufficiency and infertility. The Fanconi anemia pathway and premature ovarian insufficiency are closely associated.

Impact of chronic benzene poisoning on aberrant mitochondrial DNA methylation: A prospective observational study

Benzene is used as an industrial solvent, which may result in chronic benzene poisoning (CBP). Several studies suggested that CBP was associated with mitochondrial epigenetic regulation. This study aimed to explore the potential relation between CBP and mitochondrial DNA (mtDNA) methylation. This prospective observational study enrolled CBP patients admitted to Shenzhen Prevention and Treatment Center for Occupational Diseases hospital and healthy individuals between 2018 and 2021. The white blood cell (WBC), red blood cell (RBC), hemoglobin (HB), and platelet (PLT) counts and mtDNA methylation levels were measured using blood flow cytometry and targeted bisulfite sequencing, respectively. A total of 90 participants were recruited, including 30 cases of CBP (20 females, mean age 43.0 ± 8.0 years) and 60 healthy individuals (42 females, mean age 43.5 ± 11.5 years). This study detected 168 mitochondrial methylation sites >0 in all study subjects. The mtDNA methylation levels in the CBP cases were lower than the healthy individuals [median ± interquartile-range (IQR), 25th percentile, 75th percentile: (1.140 ± 0.570, 0.965, 1.535)% vs. median ± IQR, 25th percentile, 75th percentile: (1.705 ± 0.205,1.240,2.445)%, P < 0.05]. Additionally, the spearman correlation analysis showed that the mtDNA methylation levels were positively correlated with the counts of circulating leukocytes [WBC (r = 0.048, P = 0.036)] and platelets [PLT (r = 0.129, P < 0.01)]. We provided solid evidence of association between CBP and aberrant mtDNA methylation.

Head and Neck Cancer Susceptibility and Metabolism in Fanconi Anemia

Fanconi anemia (FA) is a rare inherited, generally autosomal recessive syndrome, but it displays X-linked or dominant negative inheritance for certain genes. FA is characterized by a deficiency in DNA damage repair that results in bone marrow failure, and in an increased risk for various epithelial tumors, most commonly squamous cell carcinomas of the head and neck (HNSCC) and of the esophagus, anogenital tract and skin. Individuals with FA exhibit increased human papilloma virus (HPV) prevalence. Furthermore, a subset of anogenital squamous cell carcinomas (SCCs) in FA harbor HPV sequences and FA-deficient laboratory models reveal molecular crosstalk between HPV and FA proteins. However, a definitive role for HPV in HNSCC development in the FA patient population is unproven. Cellular metabolism plays an integral role in tissue homeostasis, and metabolic deregulation is a known hallmark of cancer progression that supports uncontrolled proliferation, tumor development and metastatic dissemination. The metabolic consequences of FA deficiency in keratinocytes and associated impact on the development of SCC in the FA population is poorly understood. Herein, we review the current literature on the metabolic consequences of FA deficiency and potential effects of resulting metabolic reprogramming on FA cancer phenotypes.

A Multidrug Approach to Modulate the Mitochondrial Metabolism Impairment and Relative Oxidative Stress in Fanconi Anemia Complementation Group A

Fanconi Anemia (FA) is a rare recessive genetic disorder characterized by aplastic anemia due to a defective DNA repair system. In addition, dysfunctional energy metabolism, lipid droplets accumulation, and unbalanced oxidative stress are involved in FA pathogenesis. Thus, to modulate the altered metabolism, Fanc-A lymphoblast cell lines were treated with quercetin, a flavonoid compound, C75 (4-Methylene-2-octyl-5-oxotetrahydrofuran-3-carboxylic acid), a fatty acid synthesis inhibitor, and rapamycin, an mTOR inhibitor, alone or in combination. As a control, isogenic FA cell lines corrected with the functional Fanc-A gene were used. Results showed that: (i) quercetin recovered the energy metabolism efficiency, reducing oxidative stress; (ii) C75 caused the lipid accumulation decrement and a slight oxidative stress reduction, without improving the energy metabolism; (iii) rapamycin reduced the aerobic metabolism and the oxidative stress, without increasing the energy status. In addition, all molecules reduce the accumulation of DNA double-strand breaks. Two-by-two combinations of the three drugs showed an additive effect compared with the action of the single molecule. Specifically, the quercetin/C75 combination appeared the most efficient in the mitochondrial and lipid metabolism improvement and in oxidative stress production reduction, while the quercetin/rapamycin combination seemed the most efficient in the DNA breaks decrement. Thus, data reported herein suggest that FA is a complex and multifactorial disease, and a multidrug strategy is necessary to correct the metabolic alterations.

Beyond base excision repair: an evolving picture of mitochondrial DNA repair

Mitochondria are highly specialised organelles required for key cellular processes including ATP production through cellular respiration and controlling cell death via apoptosis. Unlike other organelles, mitochondria contain their own DNA genome which encodes both protein and RNA required for cellular respiration. Each cell may contain hundreds to thousands of copies of the mitochondrial genome, which is essential for normal cellular function - deviation of mitochondrial DNA (mtDNA) copy number is associated with cellular ageing and disease. Furthermore, mtDNA lesions can arise from both endogenous or exogenous sources and must either be tolerated or corrected to preserve mitochondrial function. Importantly, replication of damaged mtDNA can lead to stalling and introduction of mutations or genetic loss, mitochondria have adapted mechanisms to repair damaged DNA. These mechanisms rely on nuclear-encoded DNA repair proteins that are translocated into the mitochondria. Despite the presence of many known nuclear DNA repair proteins being found in the mitochondrial proteome, it remains to be established which DNA repair mechanisms are functional in mammalian mitochondria. Here, we summarise the existing and emerging research, alongside examining proteomic evidence, demonstrating that mtDNA damage can be repaired using Base Excision Repair (BER), Homologous Recombination (HR) and Microhomology-mediated End Joining (MMEJ). Critically, these repair mechanisms do not operate in isolation and evidence for interplay between pathways and repair associated with replication is discussed. Importantly, characterising non-canonical functions of key proteins and understanding the bespoke pathways used to tolerate, repair or bypass DNA damage will be fundamental in fully understanding the causes of mitochondrial genome mutations and mitochondrial dysfunction.

Beyond DNA repair and chromosome instability-Fanconi anaemia as a cellular senescence-associated syndrome

Fanconi anaemia (FA) is the most frequent inherited bone marrow failure syndrome, due to mutations in genes encoding proteins involved in replication fork protection, DNA interstrand crosslink repair and replication rescue through inducing double-strand break repair and homologous recombination. Clinically, FA is characterised by aplastic anaemia, congenital defects and cancer predisposition. In in vitro studies, FA cells presented hallmarks defining senescent cells, including p53-p21 axis activation, altered telomere length, mitochondrial dysfunction, chromatin alterations, and a pro-inflammatory status. Senescence is a programme leading to proliferation arrest that is involved in different physiological contexts, such as embryogenesis, tissue remodelling and repair and guarantees tumour suppression activity. However, senescence can become a driving force for developmental abnormalities, aging and cancer. Herein, we summarise the current knowledge in the field to highlight the mutual relationships between FA and senescence that lead us to consider FA not only as a DNA repair and chromosome fragility syndrome but also as a "senescence syndrome".

FANCD2 modulates the mitochondrial stress response to prevent common fragile site instability

Common fragile sites (CFSs) are genomic regions frequently involved in cancer-associated rearrangements. Most CFSs lie within large genes, and their instability involves transcription- and replication-dependent mechanisms. Here, we uncover a role for the mitochondrial stress response pathway in the regulation of CFS stability in human cells. We show that FANCD2, a master regulator of CFS stability, dampens the activation of the mitochondrial stress response and prevents mitochondrial dysfunction. Genetic or pharmacological activation of mitochondrial stress signaling induces CFS gene expression and concomitant relocalization to CFSs of FANCD2. FANCD2 attenuates CFS gene transcription and promotes CFS gene stability. Mechanistically, we demonstrate that the mitochondrial stress-dependent induction of CFS genes is mediated by ubiquitin-like protein 5 (UBL5), and that a UBL5-FANCD2 dependent axis regulates the mitochondrial UPR in human cells. We propose that FANCD2 coordinates nuclear and mitochondrial activities to prevent genome instability.

Re-definition and supporting evidence toward Fanconi Anemia as a mitochondrial disease: Prospects for new design in clinical management

Fanconi anemia (FA) has been investigated since early studies based on two definitions, namely defective DNA repair and proinflammatory condition. The former definition has built up the grounds for FA diagnosis as excess sensitivity of patients’ cells to xenobiotics as diepoxybutane and mitomycin C, resulting in typical chromosomal abnormalities. Another line of studies has related FA phenotype to a prooxidant state, as detected by both in vitro and ex vivo studies. The discovery that the FA group G (FANCG) protein is found in mitochondria (Mukhopadhyay et al., 2006) has been followed by an extensive line of studies providing evidence for multiple links between other FA gene products and mitochondrial dysfunction. The fact that FA proteins are encoded by nuclear, not mitochondrial DNA does not prevent these proteins to hamper mitochondrial function, as it is recognized that most mitochondrial proteins are of nuclear origin. This body of evidence supporting a central role of mitochondrial dysfunction, along with redox imbalance in FA, should lead to the re-definition of FA as a mitochondrial disease. A body of literature has demonstrated the beneficial effects of mitochondrial cofactors, such as α-lipoic acid, coenzyme Q10, and carnitine on patients affected by mitochondrial diseases. Altogether, this re-definition of FA as a mitochondrial disease and the prospect use of mitochondrial nutrients may open new gateways toward mitoprotective strategies for FA patients. These strategies are expected to mitigate the mitochondrial dysfunction and prooxidant state in FA patients, and potentially protect transplanted FA patients from post-transplantation malignancies.

Identification of metabolic changes leading to cancer susceptibility in Fanconi anemia cells

Fanconi anemia (FA) is a chromosomal instability disorder of bone marrow associated with aplastic anemia, congenital abnormalities and a high risk of malignancies. The identification of more than two dozen FA genes has revealed a plethora of interacting proteins that are mainly involved in repair of DNA interstrand crosslinks (ICLs). Other important findings associated with FA are inflammation, oxidative stress response, mitochondrial dysfunction and mitophagy. In this work, we performed quantitative proteomic and metabolomic analyses on defective FA cells and identified a number of metabolic abnormalities associated with cancer. In particular, an increased de novo purine biosynthesis, a high concentration of fumarate, and an accumulation of purinosomal clusters were found. This was in parallel with decreased OXPHOS and altered glycolysis. On the whole, our results indicate an association between the need for nitrogenous bases upon impaired DDR in FA cells with a subsequent increase in purine metabolism and a potential role in oncogenesis.

TFG-maintaining stability of overlooked FANCD2 confers early DNA-damage response

Emerging Fanconi Anemia (FA) signaling in the field of cancer research annotates the extreme importance of its center player, Fanconi Anemia complementation group D2 (FANCD2) in protecting human cells from going awry. However, a previously-unrecognized form of FANCD2, namely FANCD2-V2, is understudied. We report TRK-Fused Gene (TFG) is critical for roles played by FANCD2-V2 in early responses to DNA damage, but not for FANCD2-V1, the long-known form of FANCD2. FANCD2-V2 forms nuclear foci upon DNA damage, and both its focus appearance and disappearance are earlier than FANCD2-V1. The amino acid/aa 5-100 of TFG and the aa1437-1442 of FANCD2-V2 were identified to contribute to their interaction, which maintains the steady-state level of FANCD2-V2 protein. TFGΔaa5-100 or FANCD2-V2Δaa1437-1442-carrying cells could not show timely focus formation of FANCD2-V2 upon DNA damage and gained carcinogenicity over time. This study provides a previously-unknown key to unlock in-depth insights into maintaining genome stability, fostering translational studies on preventing, diagnosing and/or treating related diseases.

FANCD2 Confers a Malignant Phenotype in Esophageal Squamous Cell Carcinoma by Regulating Cell Cycle Progression

Fanconi anemia patients with germline genetic defects in FANCD2 are highly susceptible to cancers. Esophageal squamous cell carcinoma (ESCC) is a deadly cancer. Little is known about the function of FANCD2 in ESCC. For detailed molecular and mechanistic insights on the functional role of FANCD2 in ESCC, in vivo and in vitro assays and RNA sequencing approaches were used. Utilizing Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR) technology, FANCD2 knockout models were established to examine the functional impact in mouse models for tumor growth and metastasis and in vitro assays for cell growth, cell cycle, and cellular localization. Our RNA sequence analyses were integrated with public datasets. FANCD2 confers a malignant phenotype in ESCC. FANCD2 is significantly upregulated in ESCC tumors, as compared to normal counterparts. Depletion of FANCD2 protein expression significantly suppresses the cancer cell proliferation and tumor colony formation and metastasis potential, as well as cell cycle progression, by involving cyclin-CDK and ATR/ATM signaling. FANCD2 translocates from the nucleus to the cytoplasm during cell cycle progression. We provide evidence of a novel role of FANCD2 in ESCC tumor progression and its potential usefulness as a biomarker for ESCC disease management.

The FANC/BRCA Pathway Releases Replication Blockades by Eliminating DNA Interstrand Cross-Links

DNA interstrand cross-links (ICLs) represent a major barrier blocking DNA replication fork progression. ICL accumulation results in growth arrest and cell death—particularly in cell populations undergoing high replicative activity, such as cancer and leukemic cells. For this reason, agents able to induce DNA ICLs are widely used as chemotherapeutic drugs. However, ICLs are also generated in cells as byproducts of normal metabolic activities. Therefore, every cell must be capable of rescuing lCL-stalled replication forks while maintaining the genetic stability of the daughter cells in order to survive, replicate DNA and segregate chromosomes at mitosis. Inactivation of the Fanconi anemia/breast cancer-associated (FANC/BRCA) pathway by inherited mutations leads to Fanconi anemia (FA), a rare developmental, cancer-predisposing and chromosome-fragility syndrome. FANC/BRCA is the key hub for a complex and wide network of proteins that—upon rescuing ICL-stalled DNA replication forks—allows cell survival. Understanding how cells cope with ICLs is mandatory to ameliorate ICL-based anticancer therapies and provide the molecular basis to prevent or bypass cancer drug resistance. Here, we review our state-of-the-art understanding of the mechanisms involved in ICL resolution during DNA synthesis, with a major focus on how the FANC/BRCA pathway ensures DNA strand opening and prevents genomic instability.

Subcellular localization of FANCD2 is associated with survival in ovarian carcinoma

Objective: Ovarian cancer is a leading cause of death from gynecological cancers. Late diagnosis and resistance to therapy results in mortality and effective screening is required for early diagnosis and better treatments. Expression of the Fanconi Anemia complementation group D2 protein (FANCD2) is reduced in ovarian surface epithelial cells (OSE) in patients with ovarian cancer. FANCD2 has been studied for its role in DNA repair; however multiple studies have suggested that FANCD2 has a role outside the nucleus. We sought to determine whether subcellular localization of FANCD2 correlates with patient outcome in ovarian cancer.

Methods: We examined the subcellular localization of FANCD2 in primary OSE cells from consenting patients with ovarian cancer or a normal ovary. Ovarian tissue microarray was stained with anti-FANCD2 antibody by immunohistochemistry and the correlation of FANCD2 localization with patient outcomes was assessed. FANCD2 binding partners were identified by immunoprecipitation of cytoplasmic FANCD2.

Results: Nuclear and cytoplasmic localization of FANCD2 was observed in OSEs from both normal and ovarian cancer patients. Patients with cytoplasmic localization of FANCD2 (cFANCD2) experienced significantly longer median survival time (50 months), versus patients without cytoplasmic localization of FANCD2 (38 months; p < 0.05). Cytoplasmic FANCD2 was found to bind proteins involved in the innate immune system, cellular response to heat stress, amyloid fiber formation and estrogen mediated signaling.

Conclusions: Our results suggest that the presence of cytoplasmic FANCD2 modulates FANCD2 activity resulting in better survival outcome in ovarian cancer patients.

Mitoprotective Clinical Strategies in Type 2 Diabetes and Fanconi Anemia Patients: Suggestions for Clinical Management of Mitochondrial Dysfunction

Oxidative stress (OS) and mitochondrial dysfunction (MDF) occur in a number of disorders, and several clinical studies have attempted to counteract OS and MDF by providing adjuvant treatments against disease progression. The present review is aimed at focusing on two apparently distant diseases, namely type 2 diabetes (T2D) and a rare genetic disease, Fanconi anemia (FA). The pathogenetic links between T2D and FA include the high T2D prevalence among FA patients and the recognized evidence for OS and MDF in both disorders. This latter phenotypic/pathogenetic feature-namely MDF-may be regarded as a mechanistic ground both accounting for the clinical outcomes in both diseases, and as a premise to clinical studies aimed at counteracting MDF. In the case for T2D, the working hypothesis is raised of evaluating any in vivo decrease of mitochondrial cofactors, or mitochondrial nutrients (MNs) such as α-lipoic acid, coenzyme Q10, and l-carnitine, with possibly combined MN-based treatments. As for FA, the established knowledge of MDF, as yet only obtained from in vitro or molecular studies, prompts the requirement to ascertain in vivo MDF, and to design clinical studies aimed at utilizing MNs toward mitigating or delaying FA's clinical progression. Altogether, this paper may contribute to building hypotheses for clinical studies in a number of OS/MDF-related diseases.

Sex-specific hepatic lipid and bile acid metabolism alterations in Fancd2-deficient mice following dietary challenge

Defects in the Fanconi anemia (FA) DNA damage-response pathway result in genomic instability, developmental defects, hematopoietic failure, cancer predisposition, and metabolic disorders. The endogenous sources of damage contributing to FA phenotypes and the links between FA and metabolic disease remain poorly understood. Here, using mice lacking the Fancd2 gene, encoding a central FA pathway component, we investigated whether the FA pathway protects against metabolic challenges. Fancd2 ^-/- and wildtype (WT) mice were fed a standard diet (SD), a diet enriched in fat, cholesterol, and cholic acid (Paigen diet), or a diet enriched in lipid alone (high-fat diet (HFD)). Fancd2 ^-/- mice developed hepatobiliary disease and exhibited decreased survival when fed a Paigen diet but not a HFD. Male Paigen diet-fed mice lacking Fancd2 had significant biliary hyperplasia, increased serum bile acid concentration, and increased hepatic pathology. In contrast, female mice were similarly impacted by Paigen diet feeding regardless of Fancd2 status. Upon Paigen diet challenge, male Fancd2 ^-/- mice had altered expression of genes encoding hepatic bile acid transporters and cholesterol and fatty acid metabolism proteins, including Scp2/x, Abcg5/8, Abca1, Ldlr, Srebf1, and Scd-1 Untargeted lipidomic profiling in liver tissue revealed 132 lipid species, including sphingolipids, glycerophospholipids, and glycerolipids, that differed significantly in abundance depending on Fancd2 status in male mice. We conclude that the FA pathway has sex-specific impacts on hepatic lipid and bile acid metabolism, findings that expand the known functions of the FA pathway and may provide mechanistic insight into the metabolic disease predisposition in individuals with FA.

Lymphopenia With Clinical and Laboratory Features of Combined Immune Deficiency in an 11-Year-Old Female With FANCD2 Variants and Fanconi Anemia

Fanconi anemia (FA) is an inherited bone marrow failure and cancer predisposition disorder due to mutations in DNA repair pathways proteins (FANC). The dysfunctional proteins are unable to repair DNA breaks and cause genomic instability. Mutations in many of the 19 FANC genes are well characterized biochemically and clinically. Little is known about the FANCD2 gene which acts downstream of the FA-core proteins. Here we report a 11-year-old female previously diagnosed with FA and bone marrow failure. Gene sequencing demonstrated deletion of exons 2-18 and a pathologic missense mutation (c. 2444G>A, p. Arg815Gln) in FANCD2 (Chr3). Her medical history is significant for an episode of pneumococcal sepsis despite adequate vaccination. Repeated blood samples and immunophenotyping demonstrated severe lymphopenia. There were markedly low CD4+ T-cell counts with a low CD4:CD8 ratio. Changes in the composition of the B-cell population included significantly diminished absolute total B-cells, and decreased mature cells. There was no immunogenic response to vaccination against S. pneumoniae. The NK-cell count was unaffected and demonstrated normal spontaneous and stimulated cytotoxic response. Bone marrow analysis demonstrated hypocellularity without dysplasia. The clinical and laboratory features are suggestive of combined immune deficiency. FANCD2 may be involved in the transition of immature B and T cells to mature cells, a process that requires substantial DNA recombination not observed in NK cells. Additional genetic and biochemical evaluation is needed to further characterize the novel genetic and clinical findings.

A new look at molecular biology of breast cancer

In the past 25 years, incidence rates of breast cancer have risen about 30% in westernized countries. Mutations in BRCA1 and BRCA2 are the most prominent cause of breast cancer. However, these cancer susceptibility genes (BRCAs) only account for a few percent of women suffering breast tumor. With our understanding that BRCAs are Fanconi Anemia (FA) genes, investigations into the FA signaling network should provide a previously unrecognized key to unlock in-depth insights into both etiology and treatment of breast cancer. Here, we discuss utilization of the FA signaling as a unique genetic model system to expand our knowledge about the molecular biology of breast cancer and potential applications of the gained knowledge to enable preventive and therapeutic approaches for breast cancer patient care.

Multifaceted Fanconi Anemia Signaling

In 1927 Guido Fanconi described a hereditary condition presenting panmyelopathy accompanied by short stature and hyperpigmentation, now better known as Fanconi anemia (FA). With this discovery the genetic and molecular basis underlying FA has emerged as a field of great interest. FA signaling is crucial in the DNA damage response (DDR) to mediate the repair of damaged DNA. This has attracted a diverse range of investigators, especially those interested in aging and cancer. However, recent evidence suggests FA signaling also regulates functions outside the DDR, with implications for many other frontiers of research. We discuss here the characteristics of FA functions and expand upon current perspectives regarding the genetics of FA, indicating that FA plays a role in a myriad of molecular and cellular processes.

Fanconi Anemia Signaling and Cancer

The extremely high cancer incidence associated with patients suffering from a rare human genetic disease, Fanconi anemia (FA), demonstrates the importance of FA genes. Over the course of human tumor development, FA genes perform critical tumor-suppression roles. In doing so, FA provides researchers with a unique genetic model system to study cancer etiology. Here, we review how aberrant function of the 22 FA genes and their signaling network contributes to malignancy. From this perspective, we will also discuss how the knowledge discovered from FA research serves basic and translational cancer research.

FANCD2 and DNA Damage

Investigators have dedicated considerable effort to understanding the molecular basis underlying Fanconi Anemia (FA), a rare human genetic disease featuring an extremely high incidence of cancer and many congenital defects. Among those studies, FA group D2 protein (FANCD2) has emerged as the focal point of FA signaling and plays crucial roles in multiple aspects of cellular life, especially in the cellular responses to DNA damage. Here, we discuss the recent and relevant studies to provide an updated review on the roles of FANCD2 in the DNA damage response.