ITK-SYK and TEL-SYK (also known as ETV6-SYK) are human tumor-causing chimeric proteins containing the kinase region of SYK, and the membrane-targeting, N-terminal, PH-TH domain-doublet of ITK or the dimerizing SAM-PNT domain of TEL, respectively. ITK-SYK causes peripheral T cell lymphoma, while TEL-SYK was reported in myelodysplastic syndrome. BTK is a kinase highly related to ITK and to further delineate the role of the N-terminus, we generated the corresponding fusion-kinase BTK-SYK. By generating and analyzing these fusion kinases, we aim to understand the contribution of N-terminal domains to their distinct cellular behavior and oncogenic properties. The fusion kinases were found to behave differently. TEL-SYK showed stronger oncogenic capacity when compared with ITK-SYK and BTK-SYK. Furthermore, ITK-SYK and BTK-SYK triggered IL-3-independent growth of BAF3 pro-B cells. In contrast to BTK-SYK and TEL-SYK, which predominantly localized in perinuclear region and cytoplasm respectively, ITK-SYK exhibits a more diverse cellular distribution, being present in the nucleus, cytoplasm and membrane-bound compartments. Notably, we observed that ITK-SYK undergoes activation-mediated nuclear translocation, a phenomenon that is uncommon among kinases. This unique feature of ITK-SYK is therefore of particular interest due to its potential connection to its transforming capability.
MicroRNAs (miRNAs) are key regulators in Acute Myeloid Leukemia AML, affecting gene expression, including that of CD markers and impacting mutations within leukemic cells. Mutations in AML can alter miRNA profiles, which can affect the expression of CD markers and contribute to disease progression by influencing cellular processes such as differentiation, proliferation, and apoptosis. Here, we examined the interplay of cell surface protein expression (CD markers), DNA mutations, and microRNA expression in AML patients. We included 32 recently diagnosed AML patients, and CD marker expression was evaluated using flow cytometry and molecular techniques. This study aims to delve into this relationship within the context of AML, elucidating its potential implications for diagnosis, prognosis, and therapeutic interventions. Mutations were scrutinized in six patients using Whole-Exome Sequencing (WES), while quantitative PCR (qPCR) was employed to investigate the expression levels of nine microRNAs. Subsequently, a comprehensive interaction network was constructed using Cytoscape software, focusing on genes with significant mutations and their corresponding microRNAs. Cell surface protein expression analysis revealed upregulation of CD45, CD99, CD34, HLA-DR, CD38, CD13, CD33, MPO, CD15 and CD117 in AML patients. The molecular analysis results unveiled mutations in specific genes (FLT3, KIT, PTPN11, BCR, DNMT3A, and NRAS) targeted by nine microRNAs. Notably, eight microRNAs exhibited heightened expression levels. Network analysis highlighted interactions between the PTPN11 gene and six scrutinized microRNAs. Understanding the regulatory dynamics between gene mutations and microRNAs in AML patients is pivotal for unraveling the disease’s molecular mechanisms and identifying potential therapeutic targets. Further exploration into the functional roles of microRNAs in gene regulation and AML pathogenesis is warranted to validate their potential as therapeutic targets, diagnostic markers, and advanced treatment strategies.
Extracellular vesicles (EVs) function as natural delivery vectors and mediators of biological signals across tissues. Here, by leveraging these functionalities, we show that EVs decorated with an antibody-binding moiety specific for the fragment crystallizable (Fc) domain can be used as a modular delivery system for targeted cancer therapy. The Fc-EVs can be decorated with different types of immunoglobulin G antibody and thus be targeted to virtually any tissue of interest. Following optimization of the engineered EVs by screening Fc-binding and EV-sorting moieties, we show the targeting of EVs to cancer cells displaying the human epidermal receptor 2 or the programmed-death ligand 1, as well as lower tumour burden and extended survival of mice with subcutaneous melanoma tumours when systemically injected with EVs displaying an antibody for the programmed-death ligand 1 and loaded with the chemotherapeutic doxorubicin. EVs with Fc-binding domains may be adapted to display other Fc-fused proteins, bispecific antibodies and antibody-drug conjugates. Extracellular vesicles decorated with an antibody-binding moiety specific for the fragment crystallizable domain can be used as a modular delivery system for targeted cancer therapy.
Acute myeloid leukaemia (AML) is an aggressive leukaemia characterised by uncontrolled blast cell proliferation. miRNAs and Clusters of Differentiation (CD) molecules play essential roles in AML progression. This study aims to investigate the effect of COVID-19 on the expression of circulating miRNA and CD molecules in AML. This cross-sectional study recruited 32 AML patients and 20 controls. Blood samples were collected and analysed using molecular cytogenetic, miRNA/mRNA expression, and flow cytometry techniques. The expression of miRNAs varied significantly between patients with AML and control individuals. The co-expression of these miRNAs was higher (P < 0.05), indicating that the presence of one miRNA led to increased expression of other miRNAs. A differential correlation was observed between miRNAs and CD markers. Additionally, miRNA 16, miRNA 21, and miRNA 221 showed significant downregulation (P < 0.05 and P < 0.01, respectively) in AML patients with COVID-19 infection compared to those without a disease. Interestingly, this study identified a higher expression level (P < 0.01) of miRNA 137 as a novel biomarker for AML patients. Moreover, the expression of miRNA 137 showed a high correlation (P < 0.05) with most of the CD markers examined in this study and FISH features data. Furthermore, a strong correlation (P < 0.01) was observed between CD markers and miRNA among AML patients with positive and negative COVID-19 infection. These data demonstrated that COVID-19 contributed to increased expression of microRNAs in AML patients. MicroRNA 137 was identified as a novel microRNA that exhibited significant differences between patients and healthy individuals, highlighting its role in AML pathogenesis.
AbstractHaematopoiesis dysregulation with the presence of immature myeloid and erythroid immunosuppressive cells are key characteristics of the immune escape phase of tumour development. Here, the role of in vitro generated B16F10 tumour cell‐derived extracellular vesicles (tEVs) as indirect cellular communicators, participating in tumour‐induced dysregulation of haematopoiesis, was explored. The isolated tEVs displayed features of small EVs with a size range of 100–200 nm, expressed the common EV markers CD63, CD9, and Alix, and had a spherical shape with a lipid bilayer membrane. Proteomic profiling revealed significant levels of angiogenic factors, particularly vascular endothelial growth factor (VEGF), osteopontin, and tissue factor, associated with the tEVs. Systemic administration of these tEVs in syngeneic mice induced splenomegaly and disrupted haematopoiesis, leading to extramedullary haematopoiesis, expansion of splenic immature erythroid progenitors, reduced bone marrow cellularity, medullary expansion of granulocytic myeloid suppressor cells, and the development of anaemia. These effects closely mirrored those observed in tumour‐bearing mice and were not seen after heat inactivating the tEVs. In vitro studies demonstrated that tEVs independently induced the expansion of bone marrow granulocytic myeloid suppressor cells and B cells while reducing the frequency of cells in the erythropoietic lineage. These effects of tEVs were significantly abrogated by the blockade of VEGF or heat inactivation. Our findings underscore the important role of tEVs in dysregulating haematopoiesis during the immune escape phase of cancer immunoediting, suggesting their potential as targets for addressing immune evasion and reinstating normal hematopoietic processes.
The immune escape stage in cancer immunoediting is a pivotal feature, transitioning immune-controlled tumor dormancy to progression, and augmenting invasion and metastasis. Tumors employ diverse mechanisms for immune escape, with generating immunosuppressive cells from skewed hematopoiesis being a crucial mechanism. This led us to suggest that tumor cells with immune escape properties produce factors that induce dysregulations in hematopoiesis. In support of this suggestion, this study found that mice bearing advanced-stage tumors exhibited dysregulated hematopoiesis characterized by the development of splenomegaly, anemia, extramedullary hematopoiesis, production of immunosuppressive mediators, and expanded medullary myelopoiesis. Further ex vivo studies exhibited that conditioned medium derived from EL4lu2 cells could mediate the expansion of myeloid derived suppressor cells (MDSCs) in bone marrow cell cultures. The protein array profiling results revealed the presence of elevated levels of osteopontin (OPN), prostaglandin E2 (PGE2) and interleukin 17 (IL-17) in the culture medium derived from EL4luc2 cells. Accordingly, substantial levels of these factors were also detected in the sera of mice bearing EL4luc2 tumors. Among these factors, only PGE2 alone could increase the number of MDSCs in the BM cell cultures. This effect of PGE2 was significantly potentiated by the presence of OPN but not IL-17. Finally, in vitro treatment of EL4luc2 cells with pioglitazone, a modulator of OPN and cyclooxygenase 2 (COX-2) resulted in a significant reduction in cell proliferation in EL4luc2 cells. Our findings highlight the significant role played by tumor cell-derived OPN and PGE2 in fostering the expansion of medullary MDSCs and in promoting tumor cell proliferation. Furthermore, these intertwined cancer processes could be key targets for pioglitazone intervention.
Natural killer (NK) cells recognize virally infected cells and tumors. NK cell function depends on balanced signaling from activating receptors, recognizing products from tumors or viruses, and inhibitory receptors (such as KIR/Ly49), which recognize major histocompatibility complex class I (MHC-I) molecules. KIR/Ly49 signaling preserves tolerance to self but also conveys reactivity toward MHC-I-low target cells in a process known as NK cell education. Here, we found that NK cell tolerance and education were determined by the subcellular localization of the tyrosine phosphatase SHP-1. In mice lacking MHC-I molecules, uneducated, self-tolerant Ly49A+ NK cells showed accumulation of SHP-1 in the activating immune synapse, where it colocalized with F-actin and the signaling adaptor protein SLP-76. Education of Ly49A+ NK cells by the MHC-I molecule H2Dd led to reduced synaptic accumulation of SHP-1, accompanied by augmented signaling from activating receptors. Education was also linked to reduced transcription of Ptpn6, which encodes SHP-1. Moreover, synaptic SHP-1 accumulation was reduced in NK cells carrying the H2Dd-educated receptor Ly49G2 but not in those carrying the noneducating receptor Ly49I. Colocalization of Ly49A and SHP-1 outside of the synapse was more frequent in educated compared with uneducated NK cells, suggesting a role for Ly49A in preventing synaptic SHP-1 accumulation in NK cell education. Thus, distinct patterning of SHP-1 in the activating NK cell synapse may determine NK cell tolerance.
Background Anaemia is a major health problem worldwide. Global estimates of anaemia burden are crucial for developing appropriate interventions to meet current international targets for disease mitigation. We describe the prevalence, years lived with disability, and trends of anaemia and its underlying causes in 204 countries and territories. Methods We estimated population-level distributions of haemoglobin concentration by age and sex for each location from 1990 to 2021. We then calculated anaemia burden by severity and associated years lived with disability (YLDs). With data on prevalence of the causes of anaemia and associated cause-specific shifts in haemoglobin concentrations, we modelled the proportion of anaemia attributed to 37 underlying causes for all locations, years, and demographics in the Global Burden of Disease Study 2021. Findings In 2021, the global prevalence of anaemia across all ages was 24 center dot 3% (95% uncertainty interval [UI] 23 center dot 9-24 center dot 7), corresponding to 1 center dot 92 billion (1 center dot 89-1 center dot 95) prevalent cases, compared with a prevalence of 28 center dot 2% (27 center dot 8-28 center dot 5) and 1 center dot 50 billion (1 center dot 48-1 center dot 52) prevalent cases in 1990. Large variations were observed in anaemia burden by age, sex, and geography, with children younger than 5 years, women, and countries in sub-Saharan Africa and south Asia being particularly affected. Anaemia caused 52 center dot 0 million (35 center dot 1-75 center dot 1) YLDs in 2021, and the YLD rate due to anaemia declined with increasing Socio-demographic Index. The most common causes of anaemia YLDs in 2021 were dietary iron deficiency (cause-specific anaemia YLD rate per 100 000 population: 422 center dot 4 [95% UI 286 center dot 1-612 center dot 9]), haemoglobinopathies and haemolytic anaemias (89 center dot 0 [58 center dot 2-123 center dot 7]), and other neglected tropical diseases (36 center dot 3 [24 center dot 4-52 center dot 8]), collectively accounting for 84 center dot 7% (84 center dot 1-85 center dot 2) of anaemia YLDs. Interpretation Anaemia remains a substantial global health challenge, with persistent disparities according to age, sex, and geography. Estimates of cause-specific anaemia burden can be used to design locally relevant health interventions aimed at improving anaemia management and prevention. Funding Bill & Melinda Gates Foundation. Copyright (c) 2023 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.
Infection is common in thalassemia patients and is one of the leading causes of death. It's still unclear why these individuals are so sensitive to infection. There is strong evidence that a deficiency in the functioning of phagocytic cells plays a key role in the weakened resistance to pathogenic bacteria. The purpose of this study was to investigate the function of phagocytic cells by comparing the serum levels of granulocyte macrophage-colony stimulating factor (GM-CSF) and Neopterin in thalassemia patients to healthy people. The study included 50 thalassemia patients and 30 healthy controls. Enzyme-linked immunosorbent assay (ELISA) was applied to estimate the serum levels of GM-CSF and Neopterin. Serum levels of GM-CSF were significantly elevated in thalassemia patients when compared to healthy people (p < 0.05), while serum levels of Neopterin showed no significant change between thalassemia patients and healthy controls. Both serum levels of GM-CSF and Neopterin showed no significant difference between Splenectomized and healthy controls. Total leukocyte counts, lymphocytes, MID (monocytes), platelets, and RBC were all significantly higher in thalassemia patients compared to healthy controls. But, granulocyte counts showed no significant difference between the thalassemia patients and the healthy controls. On the other hand, total leukocytes, monocytes, lymphocytes and platelets counts were significantly raised in splenectomized patients when compared to healthy controls and non-splenectomized patients, respectively. We came to the conclusion that thalassemia patients have a high immune cell count, which is most likely due to the antigenic difficulties posed by blood transfusions. On the other hand, these patients have an impaired immune system.
Among the polypeptides that comprise the T cell receptor (TCR), only CD3ζ is found in Natural Killer (NK) cells, where it transmits signals from activating receptors such as CD16 and NKp46. NK cells are potent immune cells that recognize target cells through germline-encoded activating and inhibitory receptors. Genetic engineering of NK cells enables tumor-specific antigen recognition and, thus, has a significant promise in adoptive cell therapy. Ectopic expression of engineered TCR components in T cells leads to mispairing with the endogenous components, making a knockout of the endogenous TCR necessary. To circumvent the mispairing of TCRs or the need for knockout technologies, TCR complex expression has been studied in NK cells. In the current study, we explored the cellular processing of the TCR complex in NK cells. We observed that in the absence of CD3 subunits, the TCR was not expressed on the surface of NK cells and vice versa. Moreover, a progressive increase in surface expression of TCR between day three and day seven was observed after transduction. Interestingly, the TCR complex expression in NK92 cells was enhanced with a proteasome inhibitor (bortezomib) but not a lysosomal inhibitor (chloroquine). Additionally, we observed that the TCR complex was functional in NK92 cells as measured by estimating CD107a as a degranulation marker, IFNγ cytokine production, and killing assays. NK92 cells strongly degranulated when CD3ε was engaged in the presence of TCR, but not when only CD3 was overexpressed. Therefore, our findings encourage further investigation to unravel the mechanisms that prevent the surface expression of the TCR complex.
ABSTRACTSignaling via inhibitory KIR/Ly49 receptors preserves natural killer (NK) cell self-tolerance but also conveys NK cell reactivity towards MHC class-I low target cells in an education process. Here, we demonstrate that mouse NK cell education by H-2Dd regulates transcription of several genes in Ly49A+ NK cells including Ptpn6, encoding the phosphatase SHP-1. SHP-1 was highly expressed in uneducated NK cells, in which knock-out of Ptpn6 increased responsiveness. Following NKp46 triggering of uneducated NK cells, a higher synaptic abundance of phosphorylated SHP-1 was found relative to educated NK cells, concomitant with reduced phosphorylation of several signaling molecules, including PLC-g2, SLP-76, ZAP70/Syk and ERK1/2. SHP-1 overlapped extensively with F-actin and SLP-76 in the uneducated activating synapse of Ly49A+ NK cells, whereas a greater association between Ly49A and SHP-1 was observed in educated NK cells. Thus, our results indicate that in addition to transcriptional regulation, a distinct SHP-1 patterning in NK cell activating synapses can determine their tolerance.
Abstract Extracellular vesicles (EVs) play a key role in many physiological and pathophysiological processes and hold great potential for therapeutic and diagnostic use. Despite significant advances within the last decade, the key issue of EV storage stability remains unresolved and under investigated. Here, we aimed to identify storage conditions stabilizing EVs and comprehensively compared the impact of various storage buffer formulations at different temperatures on EVs derived from different cellular sources for up to 2 years. EV features including concentration, diameter, surface protein profile and nucleic acid contents were assessed by complementary methods, and engineered EVs containing fluorophores or functionalized surface proteins were utilized to compare cellular uptake and ligand binding. We show that storing EVs in PBS over time leads to drastically reduced recovery particularly for pure EV samples at all temperatures tested, starting already within days. We further report that using PBS as diluent was found to result in severely reduced EV recovery rates already within minutes. Several of the tested new buffer conditions largely prevented the observed effects, the lead candidate being PBS supplemented with human albumin and trehalose (PBS‐HAT). We report that PBS‐HAT buffer facilitates clearly improved short‐term and long‐term EV preservation for samples stored at ‐80°C, stability throughout several freeze‐thaw cycles, and drastically improved EV recovery when using a diluent for EV samples for downstream applications.
Introduction: There are limited published data regarding the recent incidence trends of cancer in Iraqi Kurdistan. Methods: The present study assessed the epidemiological estimates of cancer incidence, as well providing a projection of future cancer trends in the upcoming decade by analysing the population-based cancer registry between 2013 and 2019, in both the Erbil and Duhok governorates. A retrospective analysis was performed on data retrieved from the Medical Statistics Department at the Ministry of Health, Kurdistan Regional Government (KRG). Results: The total number of female cancer patients was higher in both governorates, and the total incidence of patients with cancer increased by over 2x between 2013 and 2019 in Erbil and Duhok, from 73 to 174 patients/100,000 individuals for women, and 36 to 85 patients/100,000 individuals for men. Analysis indicated that the percentage of patients with cancer is projected to increase by >2x in the current decade, from 3,457 cases to 4,547 and 4,449 cases in the Erbil governorate; and from 1,365 to 2,633 and 2,737 cases in 2028 based on LSTM and bi-LTSM analysis in the Duhok governorate. Lung cancer (LC) and female breast cancer (BC) were the most prominent types of cancers diagnosed since 2013 in both the Erbil and Duhok governorates. Conclusion: The striking pattern of trends for both present and future cancer incidence rates require urgent solutions and comprehensive efforts to control risk factors that promote the increasing incidence of cancer in these two KRG governorates.
There is limited published data on recent cancer incidence trends in Iraqi Kurdistan. Therefore, this study assesses epidemiological estimates of cancer incidence as well as the projection of future cancer trends in the upcoming decade by analysing the population-based cancer registry from 2013 to 2019 in both Erbil and Duhok governorates. A retrospective study was conducted on data retrieved from the Medical Statistics Department at the Ministry of Health, KRG. The total number of female cancer patients was higher in both governorates, and the total number of patients more than doubled from 2013 to 2019 in Erbil and Duhok, from 73 to 174 patients/100,000 population for women, and 36 to 85 patients/100,000 population for men. Data analysis indicates that the percentage of cancer patients is projected to increase in the decade from 2020-2030 from 107.4% to 234.3% in 2030 in Erbil governorate; and from 106% to 163% in Duhok governorate. Female breast cancer and lung cancer are the most prominent types of cancers since 2013 in Erbil and Duhok governorates. The striking pattern of trends for both present and future cancer incidence rates require the urgent solutions and comprehensive efforts to control risk factors that promote the continuity of cancer diseases in these two KRG governorates.
IL-15 priming of NK cells is a broadly accepted concept, but the dynamics and underlying molecular mechanisms remain poorly understood. We show that as little as 5 min of IL-15 treatment in vitro, followed by removal of excess cytokines, results in a long-lasting, but reversible, augmentation of NK cell responsiveness upon activating receptor cross-linking. In contrast to long-term stimulation, improved NK cell function after short-term IL-15 priming was not associated with enhanced metabolism but was based on the increased steady-state phosphorylation level of signalling molecules downstream of activating receptors. Inhibition of JAK3 eliminated this priming effect, suggesting a cross talk between the IL-15 receptor and ITAM-dependent activating receptors. Increased signalling molecule phosphorylation levels, calcium flux, and IFN-γ secretion lasted for up to 3 h after IL-15 stimulation before returning to baseline. We conclude that IL-15 rapidly and reversibly primes NK cell function by modulating activating receptor signalling. Our findings suggest a mechanism by which NK cell reactivity can potentially be maintained in vivo based on only brief encounters with IL-15 trans-presenting cells.
Introduction: The present study aimed to determine the alterations in the serum levels of tumor markers used to evaluate cardiac, renal and liver function, and detect the interleukin (IL)-18 rs1946518 polymorphism in breast (BC), colorectal (CRC) and prostate cancer (PCa) patients. Methods: Blood samples were collected from 65 female BC, 116 CRC, 79 PCa and 88 myocardial infarction (MI) patients, and 110 healthy individuals to determine the concentration of tumor and cardiac markers. Furthermore, the IL-18 rs1946518 polymorphism was assessed using amplification refractory mutation system (ARMS)-PCR. Results: The serum levels of the tumor markers cancer antigen 15-3 (CA 15-3), carbohydrate antigen 19-9 (CA 19-9), carcinoembryonic antigen (CEA) and total prostate-specific antigen (TPSA) were significantly increased in cancer patients compared with healthy controls. Furthermore, the activity of high-sensitivity cardiac troponin T (hs-cTnT) and creatine kinase‑myocardial band (CK-MB) was enhanced in MI patients, however, their activity was unchanged in cancer patients. The activity of alkaline phosphatase (ALP), and the serum concentration of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and urea were markedly elevated in CRC and PCa patients, respectively, compared with the control group. Although, no significant differences were observed in the -607 C/A polymorphism and allele frequency of IL-18 among BC, CRC patients and healthy individuals, the odds ratio (OR) was 1.75 for both C and A allele in BC patients. Therefore, the -607 C/A polymorphism could be considered as a risk factor for BC. Conclusion: The aforementioned results suggested that tumor markers could be considered as excellent biomarkers for the early detection of BC, CRC and PCa, whereas the concentration of liver enzymes could serve as an alternative indicator for the diagnosis of CRC and PCa. Additionally, the rs1946518 polymorphism in the IL-18 gene could be considered as a risk factor for the occurrence of BC, CRC and PCa.
Extracellular vesicles (EVs) can be functionalized to display specific protein receptors on their surface. However, surface-display technology typically labels only a small fraction of the EV population. Here, we show that the joint display of two different therapeutically relevant protein receptors on EVs can be optimized by systematically screening EV-loading protein moieties. We used cytokine-binding domains derived from tumour necrosis factor receptor 1 (TNFR1) and interleukin-6 signal transducer (IL-6ST), which can act as decoy receptors for the pro-inflammatory cytokines tumour necrosis factor alpha (TNF-α) and IL-6, respectively. We found that the genetic engineering of EV-producing cells to express oligomerized exosomal sorting domains and the N-terminal fragment of syntenin (a cytosolic adaptor of the single transmembrane domain protein syndecan) increased the display efficiency and inhibitory activity of TNFR1 and IL-6ST and facilitated their joint display on EVs. In mouse models of systemic inflammation, neuroinflammation and intestinal inflammation, EVs displaying the cytokine decoys ameliorated the disease phenotypes with higher efficacy as compared with clinically approved biopharmaceutical agents targeting the TNF-α and IL-6 pathways.
Irreversible inhibitors of Bruton tyrosine kinase (BTK), pioneered by ibrutinib, have become breakthrough drugs in the treatment of leukemias and lymphomas. Resistance variants (mutations) occur, but in contrast to those identified for many other tyrosine kinase inhibitors, they affect less frequently the "gatekeeper" residue in the catalytic domain. In this study we carried out variation scanning by creating 11 substitutions at the gatekeeper amino acid, threonine 474 (T474). These variants were subsequently combined with replacement of the cysteine 481 residue to which irreversible inhibitors, such as ibrutinib, acalabrutinib and zanubrutinib, bind. We found that certain double mutants, such as threonine 474 to isoleucine (T474I) or methionine (T474M) combined with catalytically active cysteine 481 to serine (C481S), are insensitive to ≥16-fold the pharmacological serum concentration, and therefore defined as super-resistant to irreversible inhibitors. Conversely, reversible inhibitors showed a variable pattern, from resistance to no resistance, collectively demonstrating the structural constraints for different classes of inhibitors, which may affect their clinical application.
This study evaluates the status and number of publications addressing cancers in the Kurdistan Region of Iraq (KRI). All publications about cancer as a research topic in three cities of the KRI were retrieved from local journals, and the ISI Web of Science, Scopus, and PubMed databases up to December 2019. Out of the net total of 269 studies conducted, including both local and international publications, 40.5 % were reported from Sulaimani, followed by 37.9 % from Erbil, and 21.6 % from Duhok. In international journals the highest percentage of studies concerned Sulaimani 25.3 %, with 46.2 % of these records being in PubMed, followed by 34.5 % and 19. 3 % of records in PubMed from Erbil and Duhok, respectively. In contrast, more articles published within local journals concerned Erbil and Duhok cities 18.2 % and 9.3 %, respectively). Additionally, we screened the number of authors involved in each particular published article and found that the highest percentage of papers with more than three authors concerned Sulaimani 24.9 %, followed by Erbil 16 %, then Duhok 8.2 %. Generally, the majority of the published articles originated from research based on the clinical data instead of basic studies, and patient data was mainly used in all articles in all selected cities. Moreover, a continuous increase in the number of published articles was observed in all the three cities from 2006 until 2019. Interestingly, the highest number of published articles was relevant to multiple cancers in both Erbil and Sulaimani, while the second- and third-highest number of published articles were about breast cancer and leukemia, respectively. The present study reveals a substantial and increasing contribution from Kurdish researchers in the field of cancer research, although there is a huge gap between Kurdistan and the rest of the world in terms of the number and quality of cancer research publications.