18 research outputs found

    FANCA maintains genomic stability through regulating BUBR1 acetylation

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    Indiana University-Purdue University Indianapolis (IUPUI)Fanconi Anemia (FA), a chromosomal instability syndrome, is characterized by bone marrow failure, genetic malformations, and predisposition to malignancies like acute myeloid leukemia (AML) and solid tumors. FA is caused by germline bi-allelic mutations in one of 21 known FA pathway genes and somatic mutations in FA genes are also found in a variety of sporadic cancers. Recently, numerous reports have discovered that the protective function of the FA pathway extends beyond its canonical role in regulation of DNA repair in interphase. In particular, the FA pathway has been shown to function in essential mitotic processes including spindle assembly checkpoint (SAC), cytokinesis, and centrosome maintenance. Understanding of the mechanistic origins of genomic instability leading to carcinogenesis and bone marrow failure has important scientific and clinical implications. To this end, using a micronucleus assay, we showed that both interphase DNA damage and mitotic errors contribute to genomic instability in FA ex vivo and in vivo. Functional studies of primary FA patient cells coupled with super-resolution microscopy revealed that FANCA is important for centrosome dependent spindle assembly supporting the protective role of FA pathway in mitotic processes. Furthermore, we dissected the interactions between the FA pathway and cellular kinase networks by employing a synthetic lethality sh-RNA screen targeting all human kinases. We mapped kinases that were synthetically lethal upon loss of FANCA, particularly those involved in highly conserved signal transduction pathways governing proliferation and cell cycle homeostasis. We mechanistically show that loss of FANCA, the most abundant FA subtype, results in in premature degradation of the mitotic kinase BUBR1 and faster mitotic exit. We further demonstrate that FANCA is important for PCAF-dependent acetylation of BUBR1 to prevent its premature degradation. Our results deepen our understanding of the molecular functions of the FA pathway in mitosis and uncover a mechanistic connection between FANCA and SAC phosphosignaling networks. These findings support the notion that further weakening the SAC through targeting kinases like BUBR1 in FA-deficient cancers may prove to be a rational therapeutic strategy

    The Evolving Role of TRAFs in Mediating Inflammatory Responses

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    TRAFs [tumor necrosis factor (TNF) receptor associated factors] are a family of signaling molecules that function downstream of multiple receptor signaling pathways and play a pivotal role in the biology of innate, and adaptive immune cells. Following receptor ligation, TRAFs generally function as adapter proteins to mediate the activation of intracellular signaling cascades. With the exception of TRAF1 that lacks a Ring domain, TRAFs have an E3 ubiquitin ligase activity which also contributes to their ability to activate downstream signaling pathways. TRAF-mediated signaling pathways culminate in the activation of several transcription factors, including nuclear factor-ÎșB (NF-ÎșB), mitogen-activated protein kinases (MAPKs; e.g., ERK-1 and ERK-2, JNK, and p38), and interferon-regulatory factors (IRF; e.g., IRF3 and IRF7). The biological role of TRAFs is largely due to their ability to positively or negatively regulate canonical and non-canonical NF-ÎșB signaling. While TRAF-mediated signaling regulates various immune cell functions, this review is focused on the recent advances in our knowledge regarding the molecular mechanisms through which TRAF proteins regulate, positively and negatively, inflammatory signaling pathways, including Toll–IL-1 receptors, RIG-I like receptors, and Nod-like receptors. The review also offers a perspective on the unanswered questions that need to be addressed to fully understand how TRAFs regulate inflammation

    Responding to the Humanitarian Crisis in Gaza: Damned if You do
 Damned if You don’t!

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    Palestine, since 1948, has endured frequent military occupations and uprisings, intifadas, in a limited geographic area that has resulted in one of the worst humanitarian crises. The prolonged nature of this military occupation has created a biosphere of war that is uninhabitable, whereby Palestinians suffer from physical, psychological, and social wounds. Israel also imposed restrictive measures in Gaza, making it difficult for Palestinians to obtain permits to work and travel throughout Palestine. Israel continued to intensify the restrictions on Gaza, reaching a blockade on the Gaza Strip, which cut off Palestinians from Jerusalem, where hospitals, banks, and vital services are found. This form of permanent siege resulted in a surge in the unemployment rate, poverty, and poor nutritional and wellbeing status. The siege also resulted in the largest open-air prison, as people became stuck between an incomplete life and the absence of total death. The major challenge is that humanitarian interventions, in the case of Gaza, are ineffective, as they are part of the siege framework. This is because any humanitarian aid meant for Gaza needs to be approved by Israel. Thus, when the emergency becomes chronic and humanitarian interventions become part of the siege framework, how can Gaza rebuild its health capacity in a permanent emergency, and to what extent can the humanitarian sector make a change

    Pathophysiological role of microRNA-29 in pancreatic cancer stroma

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    poster abstractBackground: Dense fibrotic stroma associated with pancreatic ductal adenocarcinoma (PDAC) has been a major obstacle for drug delivery to the tumor bed and may impede attempts to slow down PDAC progression and metastasis. However, current antistromal drugs have not improved tumor response to chemotherapy or patient survival. Thus, a better understanding of the molecular mechanisms associated with tumorstromal interactions is desperately needed to develop novel anti-stromal therapeutic approaches. MicroRNAs (miRNAs) are an abundant class of highly conserved, small non-coding RNAs that function as key regulators of eukaryotic gene expression and cellular homeostasis. miR-29 is known to play a paramount role in the fibrotic process of several organs by providing crucial functions downstream of pro-fibrotic signaling pathways such as TGF-ÎČ1 and regulates the expression of extracellular matrix (ECM) proteins, a major component in the PDAC stroma. Upregulation of TGF-ÎČ1 is associated with PDAC pathogenesis and is known to activate stromal cells. Furthermore, vascular endothelial growth factor (VEGF) that stimulates tumor angiogenesis is a predicted target of miR-29. We hypothesize that miR-29 may be misregulated in TGF-ÎČ1 activated PDAC stromal cells and lead to excessive accumulation of ECM proteins and VEGF. Kwon et al. 2015 Annual AACR Meeting Restored expression of miR-29 could be therapeutically beneficial to modulate tumorstromal interactions. Methods: Northern blot or qPCR techniques were used to assess miR-29 levels in vitro stromal cells, murine PDAC model, and PDAC patient biopsies, and stromal deposition/fibrosis was determined by Sirius red staining. In murine and human PDAC samples, stromal specific miR-29 expression was determined via in situ hybridization by co-staining pancreatic tissues with glial fibrillary acidic protein a marker for stromal cells and miR-29. miR-29 functional studies were conducted by transfection of stroma cells with synthetic miR-29 mimics and locked nucleic acid, a miR-29 inhibitor, and ECM protein/VEGF expression was analyzed by western blot analysis. The effect of miR-29 overexpression in stromal cells on cancer colony growth was evaluated by direct coculture of stromal cells ectopically expressing miR-29 with pancreatic cancer cells, and subsequently, cancer colony number and stromal accumulation was determined by crystal violet and sirius red stains respectively. Results: In both in vitro and in vivo models as well as PDAC patient biopsies, we observed loss of miR-29 is a common phenomenon of activated stromal cells, and is associated with a significant increase in ECM and VEGF accumulation. Restored expression of miR-29 in stromal cells reduced the deposition of matrix proteins, VEGF expression, and cancer colony formation in direct co-culture. Conclusion: These results provide insight into the mechanistic role of miR-29 in PDAC stroma and its potential use as an anti-stromal/angiogenic therapeutic agent

    Mitotic Errors Promote Genomic Instability and Leukemia in a Novel Mouse Model of Fanconi Anemia

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    © 2021 Edwards, Mitchell, Abdul-Sater, Chan, Sun, Sheth, He, Jiang, Yuan, Sharma, Czader, Chin, Liu, de CĂĄrcer, Nalepa, Broxmeyer, Clapp and Sierra Potchanant.Fanconi anemia (FA) is a disease of genomic instability and cancer. In addition to DNA damage repair, FA pathway proteins are now known to be critical for maintaining faithful chromosome segregation during mitosis. While impaired DNA damage repair has been studied extensively in FA-associated carcinogenesis in vivo, the oncogenic contribution of mitotic abnormalities secondary to FA pathway deficiency remains incompletely understood. To examine the role of mitotic dysregulation in FA pathway deficient malignancies, we genetically exacerbated the baseline mitotic defect in Fancc-/- mice by introducing heterozygosity of the key spindle assembly checkpoint regulator Mad2. Fancc-/-;Mad2+/- mice were viable, but died from acute myeloid leukemia (AML), thus recapitulating the high risk of myeloid malignancies in FA patients better than Fancc-/-mice. We utilized hematopoietic stem cell transplantation to propagate Fancc-/-; Mad2+/- AML in irradiated healthy mice to model FANCC-deficient AMLs arising in the non-FA population. Compared to cells from Fancc-/- mice, those from Fancc-/-;Mad2+/- mice demonstrated an increase in mitotic errors but equivalent DNA cross-linker hypersensitivity, indicating that the cancer phenotype of Fancc-/-;Mad2+/- mice results from error-prone cell division and not exacerbation of the DNA damage repair defect. We found that FANCC enhances targeting of endogenous MAD2 to prometaphase kinetochores, suggesting a mechanism for how FANCC-dependent regulation of the spindle assembly checkpoint prevents chromosome mis-segregation. Whole-exome sequencing revealed similarities between human FA-associated myelodysplastic syndrome (MDS)/AML and the AML that developed in Fancc-/-; Mad2+/- mice. Together, these data illuminate the role of mitotic dysregulation in FA-pathway deficient malignancies in vivo, show how FANCC adjusts the spindle assembly checkpoint rheostat by regulating MAD2 kinetochore targeting in cell cycle-dependent manner, and establish two new mouse models for preclinical studies of AML.This work was supported by the NIH R01-HL132921-01A1 award (DWC), St. Baldrick’s Foundation Scholar award (GN), Heroes Foundation (GN), the Bone Marrow Failure Research Fund at Riley Children’s Foundation (GN), NIH T32 HL007910 “Basic Science Studies on Gene Therapy of Blood Diseases” grant (ES), NIH Diversity Supplement 3R01HL132921-03S1 (ES), and NCI 1F30CA200227-01A1 fellowship (DE)

    Characteristics of injuries during the 2006 Lebanon conflict: a three-center retrospective study of survivors, 16 years after the conflict

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    BackgroundArmed conflict injury is a growing public health concern, particularly in regions like the Middle East and North Africa (MENA). The protracted conflicts and political unrest in this region have led to a substantial number of injuries. Despite this, there is still limited understanding of the specific injury patterns stemming from conflicts, such as the 2006 Lebanon conflict. This study aimed to assess the characteristics and burdens of injuries resulting from this conflict, which occurred 16 years prior to this research.MethodsThis retrospective study analyzed data of individuals affected by the 2006 Lebanon conflict, across three tertiary care centers. Demographics, injuries, complications, injury management, and hospitalization expenses were extracted from medical records and analyzed using SPSS version 29.0. Categorical variables were presented as counts and proportions, and continuous variables as mean ± standard deviation (SD). Hospital comparisons utilized chi-square or Fisher’s exact tests for categorical variables, and one-way ANOVAs for continuous variables. Analysis was conducted from September to November 2023.ResultsAcross three hospitals, 341 patients were studied, comprising 73.6% males and 26.4% females. Among them, a notable proportion (57.3% males and 34.1% females) fell within the 18–39 age range. Children and adolescents under 18 years accounted for 15.9% of males and 25.9% of females. Blast-related injuries predominated, with 24.5% resulting from direct damage caused by explosive parts and 33.3% from blast wave forces. Extremity trauma occurred in 49.0% of patients, and head/neck trauma in 24.9%. Common injuries, including penetrating, musculoskeletal, and traumatic brain injuries affected 34.9%, 31.1, and 10.0% of patients, respectively. Wound repair, fracture treatment, and debridement were the most performed procedures on 15.5, 13.5 and 9.7% of the patients, respectively. The total cost of care was USD 692,711, largely covered by the Ministry of Public Health (95.9%).ConclusionConflict-related injuries significantly contribute to the global burden of disease. Therefore, there is a pressing need to improve national guidelines to prioritize life-threatening cases and potential long-term disabilities. Furthermore, enhancing electronic registry systems to collect clinical data on injured patients is essential for conducting research and better understanding the needs of conflict casualties

    Bibliometric analysis of focal therapy in prostate cancer research

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    Abstract Introduction The use of focal therapies for prostate cancer (PCa) has soared, as it controls disease and is associated with minimal side effects. Bibliometric analysis examines the global research landscape on any topic to identify gaps in the research and areas for improvement and prioritize future research efforts. This study aims to examine the research outputs and trends and collaboration landscape in the field of focal therapy for PCa on a global scale. Methods We searched Medline, PubMed and Scopus for peer‐reviewed publications on our research topic using controlled keywords. Search results were limited to the period between 1980 and 2022, screened for duplicates and then included in our study based on prespecified eligibility criteria. The Bibliometrix Package was used for comprehensive science mapping analysis of co‐authorship, co‐citation and co‐occurrence analysis of countries, institutions, authors, references and keywords in this field. Results This analysis included 2578 research articles. The annual scientific production increased from one article in 1982 to 143 in 2022 (13.21%). The average citation per year was incrementally increasing, and these documents were cited around 32.52 times. The documents included in this analysis were published in 633 sources. The international collaboration index was 22.7. In total, 6280 author keywords were identified. The most used keywords were ‘prostate cancer’, ‘focal therapy’, ‘prostate’ and ‘photodynamic therapy’. Conclusion This bibliometric analysis has provided a comprehensive review of focal therapy in PCa research, highlighting both the significant growth in the field and the existing gaps that require further exploration. The study points to the need for more diverse international collaboration and exploration of various treatment modalities within the context of focal therapy

    Two heterozygous mutations in NFATC1 in a patient with Tricuspid Atresia.

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    Tricuspid Atresia (TA) is a rare form of congenital heart disease (CHD) with usually poor prognosis in humans. It presents as a complete absence of the right atrio-ventricular connection secured normally by the tricuspid valve. Defects in the tricuspid valve are so far not associated with any genetic locus, although mutations in numerous genes were linked to multiple forms of congenital heart disease. In the last decade, Knock-out mice have offered models for cardiologists and geneticists to study the causes of congenital disease. One such model was the Nfatc1(-/-) mice embryos which die at mid-gestation stage due to a complete absence of the valves. NFATC1 belongs to the Rel family of transcription factors members of which were shown to be implicated in gene activation, cell differentiation, and organogenesis. We have previously shown that a tandem repeat in the intronic region of NFATC1 is associated with ventricular septal defects. In this report, we unravel for the first time a potential link between a mutation in NFATC1 and TA. Two heterozygous missense mutations were found in the NFATC1 gene in one indexed-case out of 19 patients with TA. The two amino-acids changes were not found neither in other patients with CHDs, nor in the control healthy population. Moreover, we showed that these mutations alter dramatically the normal function of the protein at the cellular localization, DNA binding and transcriptional levels suggesting they are disease-causing

    FANCA safeguards interphase and mitosis during hematopoiesis in vivo

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    The Fanconi anemia (FA/BRCA) signaling network controls multiple genome-housekeeping checkpoints, from interphase DNA repair to mitosis. The in vivo role of abnormal cell division in FA remains unknown. Here, we quantified the origins of genomic instability in FA patients and mice in vivo and ex vivo. We found that both mitotic errors and interphase DNA damage significantly contribute to genomic instability during FA-deficient hematopoiesis and in nonhematopoietic human and murine FA primary cells. Super-resolution microscopy coupled with functional assays revealed that FANCA shuttles to the pericentriolar material to regulate spindle assembly at mitotic entry. Loss of FA signaling rendered cells hypersensitive to spindle chemotherapeutics and allowed escape from the chemotherapy-induced spindle assembly checkpoint. In support of these findings, direct comparison of DNA crosslinking and anti-mitotic chemotherapeutics in primary FANCA−/− cells revealed genomic instability originating through divergent cell cycle checkpoint aberrations. Our data indicate that FA/BRCA signaling functions as an in vivo gatekeeper of genomic integrity throughout interphase and mitosis, which may have implications for future targeted therapies in FA and FA-deficient cancers

    NFATC1 mutations impair functional interactions with GATA5 and HAND2.

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    <p>A- Wt NFATC1 or NFATC1 Mutants (P66L, I701L, P66L/I701L) were transfected with/without HAND2 and the DEGS1 promoter coupled to luciferase reporter construct in Hela cells. Six hours post transfection, media was changed and cells were harvested for luciferase assay after 36 hours. Relative luciferase activities are represented as fold activation. The data are the mean of three independent experiments done in duplicates +/− standard deviation. Wt NFATC1 and HAND2 synergistically activate DEGS1 promoter. This synergy was abrogated in all NFATC1 mutants. Significance (p<0.05) was assessed using the one-way Anova test. (* p<0.01, ** p<0.05) B- Wt NFATC1 or NFATC1 Mutants (P66L, I701L, P66L/I701L) were transfected with/without PPP3CA and with/without GATA5 to assess their combinatorial regulation of the DEGS1 promoter in HeLa cells. Six hours post transfection, media was changed and cells were harvested for luciferase assay after 36 hours. Relative luciferase activities are represented as fold activation. The data are the mean of three independent experiments done in duplicates +/− standard deviation. Wt NFATC1 cotransfected with GATA5 caused a synergistic activation of 35 fold, while transfection of Wt NFATC1 with PPP3CA and GATA5 caused even a stronger synergy reaching 68 fold. The synergestic activation was maintained in all mutants except for P66L/I701L double mutant where the synergy was totally lost. Significance (p<0.05) was assessed using the one-way Anova test. (* p<0.01, ** p<0.05).</p
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