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The tumour suppressor, Lethal (2) giant larvae [Lgl; also known as L(2)gl], is an evolutionarily conserved protein that was discovered in the vinegar fly Drosophila, where its depletion results in tissue overgrowth and loss of cell polarity. Lgl links cell polarity and tissue growth through regulation of the Notch and the Hippo signalling pathways. Lgl regulates the Notch pathway by inhibiting V-ATPase activity via Vap33. How Lgl regulates the Hippo pathway was unclear. In this current study, we show that V-ATPase activity inhibits the Hippo pathway, whereas Vap33 acts to activate Hippo signalling. Vap33 physically and genetically interacts with the actin cytoskeletal regulators RtGEF (Pix) and Git, which also bind to the Hippo protein (Hpo) and are involved in the activation of the Hippo pathway. Additionally, we show that the ADP ribosylation factor Arf79F (Arf1), which is a Hpo interactor, is involved in the inhibition of the Hippo pathway. Altogether, our data suggest that Lgl acts via Vap33 to activate the Hippo pathway by a dual mechanism: (1) through interaction with RtGEF, Git and Arf79F, and (2) through interaction and inhibition of the V-ATPase, thereby controlling epithelial tissue growth., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2024. Published by The Company of Biologists Ltd.)

A complex relationship exists between rheumatic diseases and cancer. This delicate balance between chronic inflammation and malignant cell transformation in hematologic neoplasms has been observed, but is not well defined. Large Granular Lymphocyte (LGL) leukemia is at the intersection of a clonal lymphoproliferative disease, chronic inflammation, and autoimmunity. The association between rheumatoid arthritis (RA) and the spectrum of Felty's Syndrome is well-known. Other rheumatic disorders have been reported including systemic lupus erythematosus (SLE), Sjogren's Syndrome (SS), vasculitis, Behcet's Disease (BD) and systemic sclerosis. The association between T-LGLL and rheumatic disease pathogenesis has been hypothesized, but has not yet been fully understood. Components of a shared pathogenesis includes chronic antigen stimulation, JAK-STAT pathway activation and overlap of various cytokines. We will summarize current knowledge on the molecular understanding between T-LGLL and rheumatic disease. There are many potential areas of research to help meet this need and lead to development of targeted therapeutic options., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Couette, Jarjour, Brammer and Simon Meara.)

Cellular trafficking through the endosomal-lysosomal system is essential for the transport of cargo proteins, receptors and lipids from the plasma membrane inside the cells and across membranous organelles. By acting as sorting stations, vesicle compartments direct the fate of their content for degradation, recycling to the membrane or transport to the trans-Golgi network. To effectively communicate with their neighbors, cells need to regulate their compartmentation and guide their signaling machineries to cortical membranes underlying these contact sites. Endosomal trafficking is indispensable for the polarized distribution of fate determinants, adaptors and junctional proteins. Conversely, endocytic machineries cooperate with polarity and scaffolding components to internalize receptors and target them to discrete membrane domains. Depending on the cell and tissue context, receptor endocytosis can terminate signaling responses but can also activate them within endosomes that act as signaling platforms. Therefore, cell homeostasis and responses to environmental cues rely on the dynamic cooperation of endosomal-lysosomal machineries with polarity and signaling cues. This review aims to address advances and emerging concepts on the cooperative regulation of endocytosis, polarity and signaling, primarily in Drosophila melanogaster and discuss some of the open questions across the different cell and tissue types that have not yet been fully explored.

Flow cytometric (FCM) analysis of the constant region 1 of the T-cell receptor β chain (TRBC1) expression for assessing Tαβ-cell clonality has been recently validated. However, its utility for the diagnosis of clonality of T-large granular lymphocytic leukemia (T-LGLL) needs to be confirmed, since more mature Tαβ cells (i.e., T-LGL normal-counterpart) show broader TRBC1 + /TRBC1 - ratios vs. total Tαβ cells. We compared the distribution and absolute counts of TRBC1 + and TRBC1 - Tαβ-LGL in blood containing polyclonal ( n = 25) vs. clonal ( n = 29) LGL. Overall, polyclonal TRBC1 + or TRBC1 - Tαβ-LGL ranged between 0.36 and 571 cells/μL (3.2-91% TRBC1 + cells), whereas the clonal LGL cases showed between 51 and 11,678 cells/μL (<0.9% or >96% TRBC1 + cells). Among the distinct TCRVβ families, the CD28 - effector-memory and terminal-effector polyclonal Tαβ cells ranged between 0 and 25 TRBC1 + or TRBC1 - cells/μL and between 0 and 100% TRBC1 + cells, while clonal LGL ranged between 32 and 5515 TRBC1 + or TRBC1 - cells/μL, representing <1.6% or >98% TRBC1 + cells. Our data support the utility of the TRBC1-FCM assay for detecting T-cell clonality in expansions of Tαβ-LGL suspected of T-LGLL based on altered percentages of TRBC1 + Tαβ cells. However, in the absence of lymphocytosis or in the case of TαβCD4-LGL expansion, the detection of increased absolute cell counts by the TRBC1-FCM assay for more accurately defined subpopulations of Tαβ-LGL-expressing individual TCRVβ families, allows the detection of T-cell clonality, even in the absence of phenotypic aberrations.

Hepatocytes differ from columnar epithelial cells by their multipolar organization, which follows the initial formation of central lumen-sharing clusters of polarized cells as observed during liver development and regeneration. The molecular mechanism for hepatocyte polarity establishment, however, has been comparatively less studied than those for other epithelial cell types. Here, we show that the tight junction protein Par3 organizes hepatocyte polarization via cooperating with the small GTPase Cdc42 to target atypical protein kinase C (aPKC) to a cortical site near the center of cell-cell contacts. In 3D Matrigel culture of human hepatocytic HepG2 cells, which mimics a process of liver development and regeneration, depletion of Par3, Cdc42, or aPKC results in an impaired establishment of apicobasolateral polarity and a loss of subsequent apical lumen formation. The aPKC activity is also required for bile canalicular (apical) elongation in mouse primary hepatocytes. The lateral membrane-associated proteins Lgl1 and Lgl2, major substrates of aPKC, seem to be dispensable for hepatocyte polarity establishment because Lgl-depleted HepG2 cells are able to form a single apical lumen in 3D culture. On the other hand, Lgl depletion leads to lateral invasion of aPKC, and overexpression of Lgl1 or Lgl2 prevents apical lumen formation, indicating that they maintain proper lateral integrity. Thus, hepatocyte polarity establishment and apical lumen formation are organized by Par3, Cdc42, and aPKC; Par3 cooperates with Cdc42 to recruit aPKC, which plays a crucial role in apical membrane development and regulation of the lateral maintainer Lgl., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Discs large (Dlg) is an essential polarity protein and a tumor suppressor originally characterized in Drosophila but also well conserved in vertebrates. Like the majority of polarity proteins, plasma membrane (PM)/cortical localization of Dlg is required for its function in polarity and tumorigenesis, but the exact mechanisms targeting Dlg to the PM remain to be fully elucidated. Here, we show that, similar to recently discovered polybasic polarity proteins such as Lgl and aPKC, Dlg also contains a positively charged polybasic domain that electrostatically binds the PM phosphoinositides PI4P and PI(4,5)P 2 Electrostatic targeting by the polybasic domain contributes significantly to the PM localization of Dlg in follicular and early embryonic epithelial cells, and is crucial for Dlg to regulate both polarity and tumorigenesis. The electrostatic PM targeting of Dlg is controlled by a potential phosphorylation-dependent allosteric regulation of its polybasic domain, and is specifically enhanced by the interactions between Dlg and another basolateral polarity protein and tumor suppressor, Scrib. Our studies highlight an increasingly significant role of electrostatic PM targeting of polarity proteins in regulating cell polarity., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2021. Published by The Company of Biologists Ltd.)

Dorsal closure during Drosophila embryogenesis provides a robust genetic platform to study the basic cellular mechanisms that govern epithelial wound healing and morphogenesis. As dorsal closure proceeds, the lateral epithelial tissue (LE) adjacent to the dorsal opening advance contra-laterally, with a simultaneous retraction of the amnioserosa. The process involves a fair degree of coordinated cell shape changes in the dorsal most epithelial (DME) cells as well as a few penultimate rows of lateral epithelial (LE) cells (collectively referred here as Dorsolateral Epithelial (DLE) cells), lining the periphery of the amnioserosa, which in due course of time extend contra-laterally and ultimately fuse over the dorsal hole, giving rise to a dorsal epithelial continuum. The JNK-Dpp signaling in the dorsolateral epidermis, plays an instrumental role in guiding their fate during this process. A large array of genes have been reported to be involved in the regulation of this core signaling pathway, yet the mechanisms by which they do so is hitherto unclear, which forms the objective of our present study. Here we show a probable mechanism via which lgl, a conserved tumour suppressor gene, regulates the JNK-Dpp pathway during dorsal closure and epithelial morphogenesis. A conditional/targeted knock-down of lgl in the dorsolateral epithelium of embryos results in failure of dorsal closure. Interestingly, we also observed a similar phenotype in a Rab11 knockdown condition. Our experiment suggests Rab11 to be interacting with lgl as they seem to synergize in order to regulate the core JNK-Dpp signaling pathway during dorsal closure and also during adult thorax closure process., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Apical-basal polarity underpins the formation of epithelial barriers that are crucial for metazoan physiology. Although apical-basal polarity is long known to require the basolateral determinants Lethal Giant Larvae (Lgl), Discs Large (Dlg) and Scribble (Scrib), mechanistic understanding of their function is limited. Lgl plays a role as an aPKC inhibitor, but it remains unclear whether Lgl also forms complexes with Dlg or Scrib. Using fluorescence recovery after photobleaching, we show that Lgl does not form immobile complexes at the lateral domain of Drosophila follicle cells. Optogenetic depletion of plasma membrane PIP 2 or dlg mutants accelerate Lgl cortical dynamics. However, Dlg and Scrib are required only for Lgl localization and dynamic behavior in the presence of aPKC function. Furthermore, light-induced oligomerization of basolateral proteins indicates that Lgl is not part of the Scrib-Dlg complex in the follicular epithelium. Thus, Scrib and Dlg are necessary to repress aPKC activity in the lateral domain but do not provide cortical binding sites for Lgl. Our work therefore highlights that Lgl does not act in a complex but in parallel with Scrib-Dlg to antagonize apical determinants., Competing Interests: Competing interestsThe authors declare no competing or financial interests., (© 2020. Published by The Company of Biologists Ltd.)

The Hedgehog (Hh) morphogen regulates growth and patterning. Since Hh signaling is also implicated in carcinogenesis, it is conceivable that de novo Hh-secreting organizers, if formed in association with oncogenic hit could be tumor-cooperative. Here we validate this hypothesis using the Drosophila model of cooperative epithelial carcinogenesis. We generate somatic clones with simultaneous loss of tumor suppressor, Lgl, and gain of the posterior compartment selector, Engrailed (En), known to induce synthesis of Hh. We show that lgl UAS-en clones in the anterior wing compartment trigger Hh signaling cascade via cross-talk with their Ci-expressing wild type cell neighbors. Hh-Dpp signaling from clone boundaries of such ectopically formed de novo organizers in turn drive lgl carcinogenesis. By contrast, Ci-expressing lgl clones transform by autocrine and/or juxtracine activation of Hh signaling in only the posterior compartment. We further show that sequestration of the Hh ligand or loss of Dpp receptor, Tkv, in these Hh-sending or -receiving lgl clones arrested their carcinogenesis. Our results therefore reveal a hitherto unrecognized mechanism of tumor cooperation by developmental organizers, which are induced fortuitously by oncogenic hits., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Genomic analysis of cancer offers the hope of identifying new treatments or aiding in the selection of existing treatments. Rare leukemias pose additional challenges in this regard as samples may be hard to acquire and when found the underlying pathway may not be attractive to drug development since so few individuals are affected. In this case, it can be useful to identify common mutational overlap among subsets of rare leukemias to increase the number of individuals that may benefit from a targeted therapy. This chapter examines the current mutational landscape of large granular lymphocyte (LGL) leukemia with a focus on STAT3 mutations, the most common mutation in LGL leukemia to date. We examined the linkage between these mutations and autoimmune symptoms and disorders, in cases of obvious and suspected LGL leukemia. We then summarized and compared mutations in a set of other rare leukemias that also have JAK/STAT signaling pathway activation brought about by genomic changes. These include T-cell acute lymphoblastic leukemia (T-ALL), T-cell prolymphocytic leukemia (T-PLL), cutaneous T-cell lymphoma (CTCL), select peripheral T-cell lymphoma (PTCL), and adult T-cell leukemia/lymphoma (ATLL). Though STAT3 activation is common in these leukemias, the way in which it is achieved, such as the activating cytokine pathway and/or the co-mutational background, is quite diverse., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The Par polarity complex, consisting of Par3, Par6 and atypical protein kinase C (aPKC), plays a crucial role in the establishment and maintenance of cell polarity. Although activation of aPKC is critical for polarity, how this is achieved is unclear. The developing zebrafish epidermis, along with its apical actin-based projections, called microridges, offers a genetically tractable system for unraveling the mechanisms of the cell polarity control. The zebrafish aPKC regulates elongation of microridges by controlling levels of apical Lgl, which acts as a pro-elongation factor. Here, we show that the nucleoporin Nup358 (also known as RanBP2) - a component of the nuclear pore complex and a part of cytoplasmic annulate lamellae (AL) - SUMOylates zebrafish aPKC. Nup358-mediated SUMOylation controls aPKC activity to regulate Lgl-dependent microridge elongation. Our data further suggest that cytoplasmic AL structures are the possible site for Nup358-mediated aPKC SUMOylation. We have unraveled a hitherto unappreciated contribution of Nup358-mediated aPKC SUMOylation in cell polarity regulation.This article has an associated First Person interview with the first author of the paper., Competing Interests: Competing interestsThe authors declare no competing or financial interests., (© 2019. Published by The Company of Biologists Ltd.)

Metazoan cell polarity is controlled by a set of highly conserved proteins. Lethal giant larvae (Lgl) functions in apical-basal polarity through phosphorylation-dependent interactions with several other proteins as well as the plasma membrane. Phosphorylation of Lgl by atypical protein kinase C (aPKC), a component of the partitioning-defective (Par) complex in epithelial cells, excludes Lgl from the apical membrane, a crucial step in the establishment of epithelial cell polarity. We present the crystal structures of human Lgl2 in both its unphosphorylated and aPKC-phosphorylated states. Lgl2 adopts a double β-propeller structure that is unchanged by aPKC phosphorylation of an unstructured loop in its second β-propeller, ruling out models of phosphorylation-dependent conformational change. We demonstrate that phosphorylation controls the direct binding of purified Lgl2 to negative phospholipids in vitro. We also show that a coil-helix transition of this region that is promoted by phosphatidylinositol 4,5-bisphosphate (PIP 2 ) is also phosphorylation-dependent, implying a highly effective phosphorylative switch for membrane association., Competing Interests: The authors declare no conflict of interest.

In the companion paper by Ufimtsev and Levitt [Ufimtsev IS, Levitt M (2019) Proc Natl Acad Sci USA , 10.1073/pnas.1821512116], we presented a method for unsupervised solution of protein crystal structures and demonstrated its utility by solving several test cases of known structure in the 2.9- to 3.45-Å resolution range. Here we apply this method to solve the crystal structure of a 966-amino acid construct of human lethal giant larvae protein (Lgl2) that resisted years of structure determination efforts, at 3.2-Å resolution. The structure was determined starting with a molecular replacement (MR) model identified by unsupervised refinement of a pool of 50 candidate MR models. This initial model had 2.8-Å RMSD from the solution. The solved structure was validated by comparison with a model subsequently derived from an alternative crystal form diffracting to higher resolution. This model could phase an anomalous difference Fourier map from an Hg derivative, and a single-wavelength anomalous dispersion phased density map made from these sites aligned with the refined structure., Competing Interests: The authors declare no conflict of interest., (Copyright © 2019 the Author(s). Published by PNAS.)

Tissue homeostasis and repair relies on proper communication of stem cells and their differentiating daughters with the local tissue microenvironment. In the Drosophila male germline adult stem cell lineage, germ cells proliferate and progressively differentiate enclosed in supportive somatic cyst cells, forming a small organoid, the functional unit of differentiation. Here we show that cell polarity and vesicle trafficking influence signal transduction in cyst cells, with profound effects on the germ cells they enclose. Our data suggest that the cortical components Dlg, Scrib, Lgl and the clathrin-mediated endocytic (CME) machinery downregulate epidermal growth factor receptor (EGFR) signaling. Knockdown of dlg, scrib, lgl, or CME components in cyst cells resulted in germ cell death, similar to increased signal transduction via the EGFR, while lowering EGFR or downstream signaling components rescued the defects. This work provides insights into how cell polarity and endocytosis cooperate to regulate signal transduction and sculpt developing tissues., (Copyright © 2019 The Author(s). Published by Elsevier Inc. All rights reserved.)

Apical-basal polarity is a common trait that underlies epithelial function. Although the asymmetric distribution of cortical polarity proteins works in a functioning equilibrium, it also retains plasticity to accommodate cell division, during which the basolateral determinant Lgl is released from the cortex. Here, we investigated how Lgl restores its cortical localization to maintain the integrity of dividing epithelia. We show that cytoplasmic Lgl is reloaded to the cortex at mitotic exit in Drosophila epithelia. Lgl cortical localization depends on protein phosphatase 1, which dephosphorylates Lgl on the serines phosphorylated by aPKC and Aurora A kinases through a mechanism that relies on the regulatory subunit Sds22 and a PP1-interacting RVxF motif of Lgl. This mechanism maintains epithelial polarity and is of particular importance at mitotic exit to couple Lgl cortical reloading with the polarization of the apical domain. Hence, PP1-mediated dephosphorylation of Lgl preserves the apical-basal organization of proliferative epithelia., (Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: The outcome for chronic myelogenous leukemia (CML) patients presented in the chronic phase has changed dramatically since the introduction of tyrosine kinase inhibitor (TKI) therapy. Notably, an increased incidence of large granular lymphocytes (LGLs), which is related to immunological conditions, appears to be predictive of a favorable outcome for dasatinib therapy. We therefore examined the immunological characteristics of CML patients during dasatinib therapy by determining the plasma concentrations of five different biomarkers., Methods: The plasma levels of biomarkers, specifically interleukin-6, platelet-derived microparticles (PDMPs), soluble vascular cell adhesion molecule 1 (sVCAM-1), transforming growth factor (TGF) β 1 , and soluble cytotoxic T lymphocyte-associated antigen-4 (sCTLA-4), were measured by ELISA at baseline and after 2 and 6 months of TKI treatment. The incidence of LGLs was estimated by microscopic examination., Results: The levels of PDMPs, sVCAM-1, and TGFβ 1 were significantly elevated in patients with CML. Dasatinib treatment was associated with a significant reduction in the levels of these markers and with an increased incidence of LGLs compared with imatinib or nilotinib treatment. In addition, an increased incidence of LGLs was significantly correlated with a decreased sCTLA-4 level during dasatinib therapy., Conclusion: The assessment of the levels of specific biomarkers may be beneficial to understand the immunological conditions of patients with CML during dasatinib treatment., Competing Interests: Disclosure The authors report no conflicts of interest in this work.

Aggressive NK cell leukemia (ANKL) is a rare malignant lymphoproliferative disorder of mature NK cells closely associated with Epstein-Barr virus (EBV) and more common in East Asia than in other areas. Significant variations exist in the morphology of ANKL tumor cells, from typical large granular lymphocyte morphology to highly atypical features with basophilic cytoplasm containing azurophilc granules. The main involved sites are hepatosplenic lesions, bone marrow and peripheral blood, and nasal or skin lesions are infrequent. A fever and liver dysfunction with an often rapidly progressive course are the main clinical symptoms, including hemophagocytic syndrome and disseminated intravascular coagulation. Although the outcome had been dismal for decades, with a median survival of less than three months, the introduction of combined chemotherapy including L-asparaginase and allogeneic hematopoietic cell transplantation has helped achieve a complete response and potential cure for some patients. With the advent of next-generation sequencing technologies, molecular alterations of ANKL have been elucidated, and dysfunctions in several signaling pathways, including the JAK/STAT pathway, have been identified. Novel target approaches to managing these abnormalities might help improve the prognosis of patients with ANKL.

Since the first identification of the Scribble polarity module proteins as a new class of tumour suppressors that regulate both cell polarity and proliferation, an increasing amount of evidence has uncovered a broader role for Scribble, Dlg and Lgl in the control of fundamental cellular functions and their signalling pathways. Here, we review these findings as well as discuss more specifically the role of the Scribble module in PCP signalling., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Objectives: Oncogenic potential of Notch signaling and its cooperation with other factors to affect proliferation are widely established. Notch exhibits a cooperative effect with loss of a cell polarity gene, scribble to induce neoplastic overgrowth. Oncogenic Ras also show cooperative effect with loss of cell polarity genes such as scribble (scrib), lethal giant larvae (lgl) and discs large to induce neoplastic overgrowth and invasion. Our study aims at assessing the cooperation of activated Notch with loss of function of lgl in tumor overgrowth, and the mode of JNK signaling activation in this context., Results: In the present study, we use Drosophila as an in vivo model to show the synergy between activated Notch (N act ) and loss of function of lgl (lgl-IR) in tumor progression. Coexpression of N act and lgl-IR results in massive tumor overgrowth and displays hallmarks of cancer, such as MMP1 upregulation and loss of epithelial integrity. We further show activation of JNK signaling and upregulation of its receptor, Grindelwald in N act /lgl-IR tumor. In contrast to previously described Notch act /scrib -/- tumor, our experiments in N act /lgl-IR tumor showed the presence of dying cells along with tumorous overgrowth.

Feline large granular lymphocyte (LGL) lymphoma is an uncommon subtype of lymphoma characterized by a grave prognosis and scarce response to chemotherapy. There are limited reports on clinico-pathological and prognostic factors. One-hundred and 9 cats with newly diagnosed LGL lymphoma that underwent initial staging (including hematology, serum biochemistry, thoracic radiographs and abdominal ultrasound), and followed-up were retrospectively evaluated. LGL lymphoma was localized within the gastrointestinal tract with or without extra-intestinal involvement in 91.7% of the cases, and at extra-gastrointestinal sites in 8.3%. Symptoms were frequent. Anemia (31.2%) and neutrophilia (26.6%) were commonly observed, and 14 (12.8%) cats had neoplastic circulating cells. Frequent biochemistry abnormalities included elevated ALT (39.4%) and hypoalbuminemia (28.4%). Twenty (54.1%) of 37 cats had elevated serum LDH. Treatment varied among cats, and included surgery (11%), chemotherapy (23%), corticosteroids (38.5%) and no treatment (27.5%). Median time to progression (MTTP) was 5 days, and median survival time (MST) 21 days. MST was significantly shorter in the case of substage b, circulating neoplastic cells, lack of chemotherapy administration, and lack of treatment response. A small subset of cats (7.3%) survived more than 6 months, suggesting that a more favorable clinical course can be found among LGL lymphoma patients., (© 2017 John Wiley & Sons Ltd.)

Despite their emergence as an important class of noncoding RNAs involved in cancer cell transformation, invasion, and migration, the precise role of microRNAs (miRNAs) in tumorigenesis remains elusive. To gain insights into how miRNAs contribute to primary tumor formation, we conducted an RNA sequencing (RNA-Seq) analysis of Drosophila wing disc epithelial tumors induced by knockdown of a neoplastic tumor-suppressor gene (nTSG) lethal giant larvae ( lgl ), combined with overexpression of an active form of oncogene Ras ( Ras V12 ), and identified 51 mature miRNAs that changed significantly in tumorous discs. Followed by in vivo tumor enhancer and suppressor screens in sensitized genetic backgrounds, we identified 10 tumor-enhancing (TE) miRNAs and 11 tumor-suppressing (TS) miRNAs that contributed to the nTSG defect-induced tumorigenesis. Among these, four TE and three TS miRNAs have human homologs. From this study, we also identified 29 miRNAs that individually had no obvious role in enhancing or alleviating tumorigenesis despite their changed expression levels in nTSG tumors. This systematic analysis, which includes both RNA-Seq and in vivo functional studies, helps to categorize miRNAs into different groups based on their expression profile and functional relevance in epithelial tumorigenesis, whereas the evolutionarily conserved TE and TS miRNAs provide potential therapeutic targets for epithelial tumor treatment., Competing Interests: CONFLICTS OF INTEREST The authors declare no potential conflicts of interest.

Large granular lymphocyte leukemia (LGL-L) is defined morphologically as a group of lymphoproliferative disorders, including T-cell large granular lymphocytic leukemia (T-LGL-L), chronic lymphoproliferative disorders of NK cells (CLPD-NK), and aggressive NK cell leukemia. We investigated the morphological features of LGL leukemic cells in LGL-L patients to identify screening methods best suited to application in daily clinical practice. LGL leukemic cells were mostly indistinguishable from normal LGL; however, we developed a simplified approach to distinguishing among these cells, in which lymphocyte  % and the proportion of granular lymphocytes among lymphocytes (GL %) can serve as parameters at the cut-off values of 52 and 50 %, respectively. We confirmed the accuracy of these methods in validation groups. It may be useful to evaluate GL % to screen for LGL-L using a cut-off threshold of 50 when Lym % exceeds 52 in the peripheral blood examination in cases in which LGL-L is suspected in daily practice while keeping clinical context and the coefficient of variation of these parameters under consideration.

Large granular lymphocytes (LGLs) are large lymphocytes with azurophilic granules in their cytoplasm. LGLs are either natural killer (NK) cells or T lymphocytes. Expansions of the LGLs in the peripheral blood are seen in various conditions, including three clonal disorders: T-cell LGL (T-LGL) leukemia, chronic lymphoproliferative disorders of NK cells (CLPD-NK), and aggressive NK-cell leukemia (ANKL). However, the monoclonal and polyclonal expansion of LGLs has been associated with many other conditions. The present article describes these LGL disorders, with special emphasis on the clinical features, pathogenesis, and treatments of the three above-mentioned clonal disorders.

Many organs form by invaginating and rolling flat epithelial cell sheets into tubes. Invagination of the ventral midline of the neural plate forms the median hinge point (MHP), an event that elevates the neural folds and is essential for neural tube closure (NTC). MHP formation involves dynamic spatiotemporal modulations of cell shape, but how these are achieved is not understood. Here, we show that cell-cycle-dependent BMP and TGFβ antagonism elicits MHP formation by dynamically regulating interactions between apical (PAR complex) and basolateral (LGL) polarity proteins. TGFβ and BMP-activated receptor (r)-SMADs [phosphorylated SMAD2 or SMAD3 (pSMAD2,3), or phosphorylated SMAD1, SMAD5 or SMAD8 (pSMAD1,5,8)] undergo cell-cycle-dependent modulations and nucleo-cytosolic shuttling along the apicobasal axis of the neural plate. Non-canonical TGFβ and BMP activity in the cytosol determines whether pSMAD2,3 or pSMAD1,5,8 associates with the tight junction (PAR complex) or with LGL, and whether cell shape changes can occur at the MHP. Thus, the interactions of BMP and TGFβ with polarity proteins dynamically modulate MHP formation by regulating r-SMAD competition for tight junctions and r-SMAD sequestration by LGL., (© 2017. Published by The Company of Biologists Ltd.)

Large granular lymphocyte leukemia (LGL-L) has been morphologically defined as a group of lymphoproliferative disorders, including T-cell large granular lymphocytic leukemia (T-LGL-L), chronic lymphoproliferative disorders of NK cells (CLPD-NK) and aggressive NK cell leukemia. We investigated the morphological features of LGL leukemic cells in 26 LGL-L patients in order to elucidate relationships with current classifications and molecular backgrounds. LGL-L cells were mostly indistinguishable from normal LGL. Patients with STAT3 SH2 domain mutations showed significantly smaller cells compared with patients without STAT3 mutations. Four patients with T-LGL-L showed smaller granular lymphocytes with a median diameter of less than 13μm, which were rarely seen in normal subjects. This small subtype of T-LGL-L was recognized among rather young patients and was associated with D661Y mutations in the STAT3 gene SH2 domain. In addition, all of them showed anemia including two cases with pure red cell aplasia. These results suggest the heterogeneity of T-LGL-L and a specific subtype with small variants of T-LGL-L., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Intracellular asymmetries, often termed cell polarity, determine how cells organize and divide to ultimately control cell fate and shape animal tissues. The tumor suppressor Lethal giant larvae (Lgl) functions at the core of the evolutionarily conserved cell polarity machinery that controls apico-basal polarization. This function relies on its restricted basolateral localization via phosphorylation by aPKC. Here, we summarize the spatial and temporal control of Lgl during the cell cycle, highlighting two ideas that emerged from our recent findings: 1) Aurora A directly phosphorylates Lgl during symmetric division to couple reorganization of epithelial polarity with the cell cycle; 2) Phosphorylation of Lgl within three conserved serines controls its localization and function in a site-specific manner. Considering the importance of phosphorylation to regulate the concentration of Lgl at the plasma membrane, we will further discuss how it may work as an on-off switch for the interaction with cortical binding partners, with implications on epithelial polarization and spindle orientation.

Dasatinib, a 2nd-generation tyrosine kinase inhibitor (TKI), can specifically induce large granular lymphocytes (LGL) in some patients with Philadelphia chromosome (Ph)-positive leukemia. To investigate the properties of the induced LGLs, we performed prospective and longitudinal analyses. From Feb 2011 to Jan 2013, a total of 17 patients with Ph-positive leukemia who were previously untreated or refractory to imatinib were enrolled. T cell receptor (TCR)-γ/δ gene rearrangements and phenotypic profiles of lymphocytes were examined before and during administration of dasatinib. LGL lymphocytosis was observed in half of the dasatinib-treated cases (LGL+ group), showing a relation to increased achievement of complete cytogenetic response within 6 months. The phenotypes of the increased lymphocytes were revealed to be mostly natural killer cells. In the LGL+ group, clonal TCR-γ gene rearrangements were frequently detected at diagnosis (six of nine cases) and persisted during therapy, compared with only two of eight in the LGL- group. The proportion of regulatory T cells to CD4+ T cells at diagnosis was lower in the LGL+ compared with the LGL- group (median 4.2 vs. 6.6 %), and this disparity was sustained throughout the therapeutic period. These results demonstrate that immunological condition at diagnosis may affect LGL lymphocytosis in some dasatinib-treated patients.

We report 2 cases of CD4(+) large granular lymphocyte (LGL) lymphocytosis occurring in patients being treated with a monoclonal antibody against tumor necrosis factor α for underlying autoimmune disorders. CD4(+) LGL lymphocytosis is a rare subset of LGL disease that has previously only been described in patients without underlying autoimmune disorders, and most demonstrate uniform coexpression of CD56 on the atypical T cells. The clinical features, with both cases occurring in patients with autoimmune disease, and immunophenotypic features, with both cases showing dim CD8 coexpression without CD56 in the CD4(+) LGLs, suggest that the reported cases are distinct from those previously described and may represent a novel T-cell LGL lymphocytosis emerging from iatrogenic immune modulation of patients with underlying autoimmune disorders., (Copyright © 2015 Elsevier Inc. All rights reserved.)

The evolutionarily conserved neoplastic tumor suppressor protein, Lethal (2) giant larvae (Lgl), plays roles in cell polarity and tissue growth via regulation of the Hippo pathway. In our recent study, we showed that in the developing Drosophila eye epithelium, depletion of Lgl leads to increased ligand-dependent Notch signaling. lgl mutant tissue also exhibits an accumulation of early endosomes, recycling endosomes, early-multivesicular body markers and acidic vesicles. We showed that elevated Notch signaling in lgl(-) tissue can be rescued by feeding larvae the vesicle de-acidifying drug chloroquine, revealing that Lgl attenuates Notch signaling by limiting vesicle acidification. Strikingly, chloroquine also rescued the lgl(-) overgrowth phenotype, suggesting that the Hippo pathway defects were also rescued. In this extraview, we provide additional data on the regulation of Notch signaling and endocytosis by Lgl, and discuss possible mechanisms by which Lgl depletion contributes to signaling pathway defects and tumorigenesis.