Mature Subtypes Research Articles

An Approach to Intersectionally Target Mature Enteroendocrine Cells in the Small Intestine of Mice.

Enteroendocrine cells (EECs) constitute only a small proportion of Villin-1 (Vil1)-expressing intestinal epithelial cells (IECs) of the gastrointestinal tract; yet, in sum, they build the largest endocrine organ of the body, with each of them storing and releasing a distinct set of peptides for the control of feeding behavior, glucose metabolism, and gastrointestinal motility. Like all IEC types, EECs are continuously renewed from intestinal stem cells in the crypt base and terminally differentiate into mature subtypes while moving up the crypt-villus axis. Interestingly, EECs adjust their hormonal secretion according to their migration state as EECs receive altering differentiation signals along the crypt-villus axis and thus undergo functional readaptation. Cell-specific targeting of mature EEC subtypes by specific promoters is challenging because the expression of EEC-derived peptides and their precursors is not limited to EECs but are also found in other organs, such as the brain (e.g., Cck and Sst) as well as in the pancreas (e.g., Sst and Gcg). Here, we describe an intersectional genetic approach that enables cell type-specific targeting of functionally distinct EEC subtypes by combining a newly generated Dre-recombinase expressing mouse line (Vil1-2A-DD-Dre) with multiple existing Cre-recombinase mice and mouse strains with rox and loxP sites flanked stop cassettes for transgene expression. We found that transgene expression in triple-transgenic mice is highly specific in I but not D and L cells in the terminal villi of the small intestine. The targeting of EECs only in terminal villi is due to the integration of a defective 2A separating peptide that, combined with low EEC intrinsic Vil1 expression, restricts our Vil1-2A-DD-Dre mouse line and the intersectional genetic approach described here only applicable for the investigation of mature EEC subpopulations.

The aryl hydrocarbon receptor maintains antitumor activity of liver resident natural killer cells after partial hepatectomy in C57BL/6J mice.

Liver-resident natural killer (lr-NK) cells are distinct from conventional NK cells and exhibit higher cytotoxicity against hepatoma via tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). However, the mechanism by which partial hepatectomy (PH) significantly suppresses TRAIL expression in lr-NK cells remains unclear. This study aimed to investigate the PH influence on the function and characteristics of liver-resident NK (lr-NK) cells using a PH mouse model. Here, we report that PH alters the differentiation pattern of NK cells in the liver, and an aryl hydrocarbon receptor (AhR) molecule is involved in these changes. Treatment with the AhR agonist 6-formylindolo[3,2-b]carbazole (FICZ) inhibited the maturation of NK cells. FICZ increased the immature subtype proportion of NK cells with high TRAIL activity and decreased the mature subtype of NK cells with low TRAIL activity. Consequently, FICZ increased the expression of TRAIL and cytotoxic activity of NK cells in the liver, and this effect was confirmed even after hepatectomy. The participation of AhR promoted FoxO1 expression in the mTOR signaling pathway involved in the maturation of NK cells, resulting in TRAIL expression. Our findings provide direct in-vivo evidence that partial hepatectomy affects lrNK cell activity through NK cell differentiation in the liver. Perioperative therapies using an AhR agonist to improve NK cell function may reduce the recurrence of hepatocellular carcinoma after hepatectomy.

Arginine Methyltransferase PRMT7 Deregulates Expression of RUNX1 Target Genes in T-Cell Acute Lymphoblastic Leukemia.

Simple SummaryApproximately 15–25% of acute lymphoblastic leukemias (ALL) originate from T-lineage cells. The prognosis of T-ALL is less favorable than in B-ALL and patients experience more often relapse, which is associated with dismal survival. No established prognostic biomarkers exist for T-ALL. Here, we identified the high expression of PRMT7 in T-ALL cells. Genetic deletion of PRMT7 decreased the colony formation of T-ALL cells and altered arginine monomethylation patterns in protein complexes associated with RNA and DNA processing. Moreover, several proteins with an established role in the pathogenesis of T-ALL had disrupted arginine monomethylation patterns. Among them was RUNX1, whose target gene expression was consequently deregulated.T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological malignancy with no well-established prognostic biomarkers. We examined the expression of protein arginine methyltransferases across hematological malignancies and discovered high levels of PRMT7 mRNA in T-ALL, particularly in the mature subtypes of T-ALL. The genetic deletion of PRMT7 by CRISPR-Cas9 reduced the colony formation of T-ALL cells and changed arginine monomethylation patterns in protein complexes associated with the RNA and DNA processing and the T-ALL pathogenesis. Among them was RUNX1, whose target gene expression was consequently deregulated. These results suggest that PRMT7 plays an active role in the pathogenesis of T-ALL.

A2 MUCUS DEFICIENCY IMPACTS INTESTINAL EPITHELIAL CELL PROLIFERATION INDEPENDENT OF THE MICROBIOTA

BackgroundIntestinal homeostasis is highly dependent on the proliferation and differentiation of intestinal epithelial cells (IEC). IEC arise from intestinal stem cells (ISCs) that reside at the bottom of intestinal crypts. Following proliferation, the IEC migrate up as transient amplifying (TA) cells, and differentiate into mature IEC subtypes. When this process is disrupted, it can lead to aberrant IEC proliferation and differentiation. Mucus production by secretory goblet cells is also crucial for intestinal homeostasis, as mucus separates the IEC from luminal microbiota. Surprisingly, mice lacking Muc2, the main protein component of mucus, display increased distal colonic IEC proliferation and crypt hyperplasia at baseline, suggesting a relationship between Muc2 production and IEC proliferation.AimsWe investigated how mucus production impacts IEC proliferation and differentiation in the intestinal crypt.MethodsWe used wildtype (Muc2+/+) and Muc2 deficient (Muc2-/-) littermates to measure distal colon crypt length and IEC proliferation pattern via microscopy. Organoids were also derived from distal colons of Muc2+/+ and Muc2-/- mice, and quantified for size, density and proliferation for 7 days to test whether the hyper-proliferation phenotype was also seen in vitro, thus epithelial-intrinsic. Crypts and organoids were collected for RNA sequencing to examine changes in IEC proliferation pathways. Proliferation assessments were repeated in germ-free (GF) Muc2+/+ and Muc2-/- mice. Muc2-/- mice were also cross-bred with Lgr5-EGFP-IRES-CreERT2 mice to investigate the contribution of ISCs to IEC hyperproliferation resulting from Muc2 deficiency.ResultsSignificant crypt hyperplasia was observed in the distal colons of Muc2-/- mice in concert with a > twofold increase in Ki67+ TA cells as compared to Muc2+/+ mice. Similarly, Muc2-/- organoids also displayed significantly greater size, density and an increased number of Ki67+ cells than Muc2+/+ organoids. Hyperproliferation was also seen in GF mice and organoids, suggesting that mucus impacts IEC proliferation independent of the microbiome. Muc2-/- Lgr5-EGFP+ mice showed no significant increase in numbers of Lgr5+ cells, indicating that Muc2 deficiency does not directly impact ISC number, but rather their proliferation and differentiation reflected in increased numbers of TA cells. RNA-sequencing results suggested that changes in lipid metabolism may underlie the increased IEC proliferation seen in Muc2-/- mice.ConclusionsMucus not only promotes IEC homeostasis by separating luminal bacteria from the intestinal epithelium, but also intrinsically modifies IEC proliferation independent of the microbiota. Taken together, our results emphasize the importance of mucus in controlling gut health through mechanisms independent of its role in barrier function.Funding AgenciesCCC, CIHRC.H.I.L.D Foundation

Prognostic Value of the Immunological Subtypes of Adolescent and Adult T-Cell Lymphoblastic Lymphoma; an Ultra-High-Risk Pro-T/CD2(-) Subtype.

Simple SummaryT-cell lymphoblastic lymphoma (T-LBL) is extremely rare and aggressive with no practical risk model defined. Considering the controversies over the prognostic value of T-LBL immunological subtypes, we re-evaluated 49 subsequent adult T-LBL patients treated according to the German Multicenter Study Group for Adult Acute Lymphoblastic Leukemia protocols, with 85.7% with complete remissions. To the best of our knowledge, this is the largest study of T-LBL diagnosed by flow-cytometry of the material obtained by fine-needle aspiration biopsy. We show that (1) CD2 status and age are powerful independent prognostic factors influencing overall survival and the risk of treatment failure; (2) the early/pro-T/CD2(−) subtype is associated with extremely poor outcomes; and (3) poor outcomes in ETP vs. non-ETP are strikingly consistent with the pro-T CD2(−) subtype. The lack of CD2 expression in T-LBL emerges as a new marker of an ultra-high-risk of treatment failure. We show here that ETP is a non-uniform entity, where the outcome depends on the CD2 status.(1) Background: T-cell lymphoblastic lymphoma (T-LBL) is extremely rare and highly aggressive, with no practical risk model defined yet. The prognostic value of T-LBL immunological subtypes is still a matter of controversy. (2) Methods: We re-evaluated 49 subsequent adult T-LBL patients treated according to the German Multicenter Study Group for Adult Acute Lymphoblastic Leukemia (GMALL) protocols, 05/93 (n = 20) and T-LBL 1/2004 (n = 29), 85.7% of which achieved complete remission (CR). (3) Results: The 5/10-year overall survival (OS) and event-free survival (EFS) were 62%/59% and 48%/43%, respectively. In 96% of patients, flow cytometry analyses defining the WHO 2008 immunophenotypes were available. Cortical, early/pro-T/CD2(−), early/pre-T/CD2(+), and mature subtypes were identified in 59.5%, 19%, 15%, and 6.5% of patients, respectively. Overall, 20% of patients had the early T-cell precursor (ETP)-LBL immunophenotype, as proposed by the WHO 2017 classification. For the early/pro-T/CD2(−) subtype, the five-year OS and EFS were 13% and 13%, while for all the other, non-pro-T subtypes, they were 69% and 67%. By multivariate analysis, only CD2(−) status and age > 35 years emerged as strong, independent factors influencing OS and EFS, while the risk of CR failure was influenced by age only (>35 years). (4) Conclusions: ETP was non-significant for OS, unless an ultra-high-risk pro-T/CD2(−) subtype was concerned.

Clinical and Pathological Evidence of Anti-GD2 Immunotherapy Induced Differentiation in Relapsed/Refractory High-Risk Neuroblastoma.

Simple SummaryThe anti-tumor activity of anti-GD2 monoclonal antibodies (mAbs) have been demonstrated by the capacity to mediate immunological cytotoxicity but also through direct cell death induction. Recently, studies with anti-GD2 mAbs for high-risk (HR)-neuroblastoma (NB) patients with measurable disease, with or without chemotherapy, have reported significant objective responses. In this subgroup of patients, we observed that, while being treated with the mAb naxitamab, some chemorefractory lesions showed long periods of stable disease. Here, we report a comprehensive imaging evaluation of those lesions correlating with histopathological demonstration of naxitamab-induced tissue differentiation. Our results suggest an undescribed mechanism of action for anti-GD2 mAbs.Background: Neuroblastic tumors (NBTs) originate from a block in the process of differentiation. Histologically, NBTs are classified in neuroblastoma (NB), ganglioneuroblastoma (GNB), and ganglioneuroma (GN). Current therapy for high-risk (HR) NB includes chemotherapy, surgery, radiotherapy, and anti-GD2 monoclonal antibodies (mAbs). Anti-GD2 mAbs induce immunological cytoxicity but also direct cell death. Methods: We report on patients treated with naxitamab for chemorefractory NB showing lesions with long periods of stable disease. Target lesions with persisting 123I-Metaiodobenzylguanidine (MIBG) uptake after 4 cycles of immunotherapy were further evaluated by functional Magnetic Resonance Imaging (MRI) and/or Fluorodeoxyglucose (FDG)-positron emission tomography (PET). MIBG avid lesions that became non-restrictive on MRI (apparent diffusion coefficient (ADC) > 1) and/or FDG-PET negative (SUV < 2) were biopsied. Results: Twenty-seven relapse/refractory (R/R) HR-NB patients were enrolled on protocol Ymabs 201. Two (7.5%) of the 27 showed persistent bone lesions on MIBG, ADC high, and/or FDG-PET negative. Forty-four R/R HR-NB patients received chemo-immunotherapy. Twelve (27%) of the 44 developed persistent MIBG+ but FDG-PET- and/or high ADC lesions. Twelve (86%) of the 14 cases identified were successfully biopsied producing 16 evaluable samples. Histology showed ganglioneuroma maturing subtype in 6 (37.5%); ganglioneuroma mature subtype with no neuroblastic component in 4 (25%); differentiating NB with no Schwannian stroma in 5 (31%); and undifferentiated NB without Schwannian stroma in one (6%). Overall, 10 (62.5%) of the 16 specimens were histopathologically fully mature NBTs. Conclusions: Our results disclose an undescribed mechanism of action for naxitamab and highlight the limitations of conventional imaging in the evaluation of anti-GD2 immunotherapy clinical efficacy for HR-NB.

Instant intra-operative neutropenia despite the emergence of banded (CD16dim/CD62Lbright) neutrophils in peripheral blood - An observational study during extensive trauma-surgery in pigs

IntroductionDeregulation of polymorphonuclear neutrophils (PMNs) is an essential step in the development of inflammatory complications upon trauma. Different neutrophil subtypes have been identified recently, however, the role of neutrophil subtypes in immunoregulation upon trauma is unclear. We hypothesize that extensive trauma surgery causes instant progressive heterogeneity of the blood neutrophil pool, and increased appearance of young (CD16dim/CD62Lbright) neutrophils in peripheral blood. Material and methodsA standardized extensive thoraco-abdominal porcine trauma surgery model was utilized, and 12 animals were included. Blood was collected at defined timepoints and neutrophil numbers and subtypes were studied by flowcytometry. Neutrophil subtypes were identified by differences in cell surface expression levels of CD16 (FcγRIII) and CD62L (L-selectin). Porcine neutrophil subtypes were further characterized after flow sorting. ResultsEleven animals survived the 3-hour surgical protocol. Neutrophil numbers dropped significantly from a mean of 8,6 ± 3,5 × 106 to 2,4 ± 1,8 × 106 cells/ml during 180 min, (p<0.001). Simultaneously, the blood PMN population became increasingly heterogeneous due to the appearance of new neutrophil subtypes. Cell sorting experiments and cytological analysis revealed that these porcine subtypes had specific morphological characteristics, mimicking their human counterparts. At baseline, 88% ± 1 percent of circulatory PMNs comprised of mature (CD16bright/CD62Lbright) PMNs, while at 3 h the blood PMN pool consisted of 59% ± 2 percent of mature subtypes (p<0.001). Despite a marked drop in neutrophil levels during surgery, absolute and relative numbers of banded (CD16dim/CD62Lbright) neutrophils continued to rise throughout surgery. ConclusionStandardized extensive trauma surgery was associated with instant progressive neutropenia and increased heterogeneity of the blood neutrophil pool. Furthermore, three different neutrophil subsets in peripheral porcine blood were identified over the course of surgery. Further studies should clarify their precise role in the development of early organ failure upon extensive trauma surgery. This for the first time exemplifies experimentally the time constraints and impact of damage control surgery after severe trauma.

Notch Signaling Molecules as Prognostic Biomarkers for Acute Myeloid Leukemia.

The role of Notch signaling in acute myeloid leukemia (AML) is still under investigation. We have previously shown that high levels of Notch receptors and ligands could interfere with drug response. In this study, the protein expression of 79 AML blast samples collected from newly diagnosed patients was examined through flow cytometry. Gamma-secretase inhibitors were used in AML mouse xenograft models to evaluate the contribution of Notch pharmacological inhibition to mouse survival. We used univariate analysis for testing the correlation and/or association between protein expression and well-known prognostics markers. All the four receptors (Notch1–4) and some ligands (Jagged2, DLL-3) were highly expressed in less mature subtypes (M0–M1). Notch3, Notch4, and Jagged2 were overexpressed in an adverse cytogenetic risk group compared to good cytogenetic risk patients. Chi-square analysis revealed a positive association between the complete remission rate after induction therapy and weak expression of Notch2 and Notch3. We also found an association between low levels of Notch4 and Jagged2 and three-year remission following allogeneic stem cell transplantation (HSCT). Accordingly, Kaplan–Meier analysis showed improved OS for patients lacking significant expression of Notch4, Jagged2, and DLL3. In vivo experiments in an AML mouse model highlighted both improved survival and a significant reduction of leukemia cell burden in the bone marrow of mice treated with the combination of Notch pan-inhibitors (GSIs) plus chemotherapy (Ara-C). Our results suggest that Notch can be useful as a prognostic marker and therapeutic target in AML.

Impact of luteinizing hormone suppression on hematopoietic recovery after intensive chemotherapy in patients with leukemia.

7039 Background: Treatment of acute leukemia with intensive chemotherapy (IC) leads to increased risk of infection and bleeding because of myelosuppression. Luteinizing hormone (LH) blockade was found to improve hematopoietic recovery in mice after radiation or chemotherapy through protection of the hematopoietic stem cells (HSCs) which express the LH receptor (Velardi et al, Nat Med 2018). We hypothesized that LH blockade improves hematopoietic recovery following IC in patients (pts) with leukemia. Methods: We assessed gene expression of the LH receptor (LHR) in lineage-specific normal and AML hematopoietic cells from a reference dataset (Corces et al, Nat Gen 2016). We conducted a retrospective analysis on pre-menopausal women with acute myeloid leukemia (AML) or acute lymphoblastic leukemia (ALL) who received IC and Lupron, given for prevention or treatment of abnormal uterine bleeding. Results: LHR was greatest in HSCs, with little or no expression in mature subtypes within the hematopoietic hierarchy. Surprisingly, LHR was expressed on blasts. Since Lupron was more commonly given in younger pts, we performed propensity matching between the Lupron groups (AML N = 64; ALL N = 49) and control (Ctrl) groups (AML N = 128; ALL N = 98 pts). Baseline characteristics including blood counts were well balanced. Pts with AML who had received Lupron had a significantly higher increase in their platelet count following IC (13.8x109/L/year vs Ctrl; p = 0.02). Pts with ALL who had received Lupron had significantly higher increase in their absolute neutrophil count (0.37x109/L/year vs Ctrl; p = 0.02). AML pts in the Lupron group received significantly less blood transfusions vs Ctrl (mean: 23.9 vs 34.7 units; P = 0.002) and less platelet transfusions (mean: 24.4 vs 32.8 units; P = 0.06). There was no difference in event-free and overall survival between the groups in each leukemia cohort. Conclusions: Lupron use in leukemia pts receiving IC was associated with improved long-term blood count recovery. It was also associated with decreased transfusion requirements in AML. Despite expression of the LHR in blasts in addition to normal HSCs, there was no effect of LH blockade on rates of leukemia relapse or death.

Low-dose radiation delays aging of human stem cells

Background & Aim Most tissues in the body harbour adult tissue stem cells (SCs) – multipotent, quiescent cells, capable of self-renewal, proliferation and differentiation into mature cellular subtypes. With the discovery of the unique properties of stem cells and their regenerative capacity came the possibility of utilizing these cells for therapeutic purposes. While very promising, stem cell therapy is thwarted by the challenge of obtaining donor-derived SCs in numbers that are sufficient to support therapy development with in vitro expansion leading to premature aging, loss of stemness and a significantly decreased functional and regenerative capacity of these cells. To address this challenge and based on the scientific reports of delayed aging following exposures to low-dose ionizing radiation in vitro and in vivo, we decided to investigate the effects of low-dose radiation (LDR) on cord-blood derived mesenchymal stem and progenitor cells (MSC/MSPC) and endothelial colony forming cells (ECFC). Methods, Results & Conclusion In our study, young, passage 4 stem cells were acutely irradiated with 10, 50 and 100 mGy gamma rays. Both SC types were aged in culture and their proliferation was monitored using Incucyte. Aging was defined as a decline in cell proliferative capacity and function. MSC function was evaluated based on the extent of chondrogenic differentiation. ECFC function was assessed by migration capacity in a scratch wound assay. The results of this study demonstrated that in vitro cultured non-irradiated MSCs and ECFCs aged significantly with cell doubling time increasing ∼3.0 fold. However, all doses of LDR treatment at early passage provided lasting effects and delayed aging, represented by improved proliferative capacity of 1.5-2.2 fold. Similarly, chondrogenic differentiation of aged MSCs decreased ∼2 fold but was restored back to young cell control levels with 50 and 100 mGy treatment. Interestingly, a 10 mGy exposure led to 50% further improvement exceeding the levels for young controls. The migratory capacity of aged ECFCs decreased ∼2 fold in comparison to young cells and was improved by ∼30% with LDR exposure. Thus, this report provides the first evidence of delayed aging and improved functional capacity of in vitro expanded mesenchymal and endothelial stem cells.

Essential Roles of Tbr1 in the Formation and Maintenance of the Orientation-Selective J-RGCs and a Group of OFF-Sustained RGCs in Mouse

In the mouse retina, more than 30 retinal ganglion cell (RGC) subtypes have been classified based on a combined metric of morphological and functional characteristics. RGCs arise from a common pool of retinal progenitor cells during embryonic stages and differentiate into mature subtypes in adult retinas. However, the cellular and molecular mechanisms controlling formation and maturation of such remarkable cellular diversity remain unknown. Here, we demonstrate that T-box transcription factor T-brain 1 (Tbr1) is expressed in two groups of morphologically and functionally distinct RGCs: the orientation-selective J-RGCs and a group of OFF-sustained RGCs with symmetrical dendritic arbors. When Tbr1 is genetically ablated during retinal development, these two RGC groups cannot develop. Ectopically expressing Tbr1 in M4 ipRGCs during development alters dendritic branching and density but not the inner plexiform layer stratification level. Our data indicate that Tbr1 plays critical roles in regulating the formation and dendritic morphogenesis of specific RGC types.

Functional Differentiation of Neural Stem Cells into Neuronal Subtypes: A Biological Tool for Developmental Neurotoxicity Studies

Neural Stem Cells (NSCs), owing to their potential to get differentiated into various mature cell subtypes including neuronal cells have proved to be an indefinite source of 'raw material' for their application in developmental neurotoxicity as well as therapeutic intervention in neurodegenerative disorders. However, applications of NSCs for such purposes have been broadly limited by lack of enough methods for their directed differentiation. Herein, we describe a chemically defined protocol for efficient differentiation of rat neural stem cells to neuronal subtypes using an 8-day time period. NSCs, subject to NGF (50 ng/mL) were differentiated into neuronal sub-types supplemented with a cocktail of growth factors and supplements. Differentiating cells revealed a gradual and significant induction in the neuronal markers and a parallel decrease in markers of stemness as confirmed by immunocytochemical and translational analysis. The expression of markers was found to be maximum at day 8 of differentiation. Such selective differentiation of NSCs into neurons could offer an imperative step towards generation of NSC derivatives that could facilitate their utilization for research studies.

Characterization of the Transmitted Virus in an Ongoing HIV-1 Epidemic Driven by Injecting Drug Use.

Understanding features of the HIV-1 transmission process has the potential to inform biological interventions for prevention. We have examined the transmitted virus in a cohort of people who inject drugs and who are at risk of HIV-1 infection through blood contamination when injecting in a group. This study focused on seven newly infected participants in St. Petersburg, Russia, who were in acute or early infection. We used end-point dilution polymerase chain reaction to amplify single viral genomes to assess the complexity of the transmitted virus. We also used deep sequencing to further assess the complexity of the virus. We interpret the results as indicating that a single viral variant was transmitted in each case, consistent with a model where the exposure to virus during transmission was limited. We also looked at phenotypic properties of the viral Env protein in isolates from acute and chronic infection. Although differences were noted, there was no consistent pattern that distinguished the transmitted variants. Similarly, despite the reduced genetic heterogeneity of the more recent subtype A HIV-1 epidemic in St. Petersburg, we did not see reduced variance in the neutralization properties compared to isolates from the more mature subtype C HIV-1 epidemic. Finally, in looking at members of injecting groups related to the acute HIV-1 infection/early subjects, we found examples of sequence linkage consistent with ongoing and rapid spread of HIV-1 in these groups. These studies emphasize the dynamic nature of this epidemic and reinforce the idea that improved prevention methods are needed.

HETEROGENEITY OF CHILDHOOD B-CELL ACUTE LYMPHOBLASTIC LEUKEMIA (EGIL SUBTYPE BIV)

Introduction. Surface immunoglobulin expression is a main immunophenotypic criteria of mature subtype of B-lineage acute lymphoblastic leukemia. Although the majority of such cases represents Burkitt leukemia/lymphoma, it was shown for several times that membrane IgM could be detected in the absence of other mature lymphomas signs. The aim of the study was to evaluate heterogeneity of childhood acute lymphoblastic leukemia (ALL) with surface IgM expression and to assess correspondence of BIV EGIL ALL subtype with Burkitt lymphoma (BL) bone marrow dissemination. Materials and methods . Immunophenotypic, cytomorfologic and genetic data of 54 BIV-ALL cases were analyzed. Results . Among the studied patients 39 had BL, while others belonged to B-cell precursor ALL (BCP-ALL). All BL patients and none of BCP-ALL patients carried C-MYC rearrangement while in BCP-ALL group in 8 cases and in any BL cases KMT2A rearrangements were found. None of BCP-ALL children had L3 morphology according to FAB classification. Conclusions. B-lineage ALL with surface IgM expression is rather heterogeneous group of cases including typical BL and rare cases of BCP-ALL even with KMT2A-rearrangements. Combination of all available diagnostic technologies will allow precise split of these two different disease and select the appropriate treatment scheme.

Prognostic Value of Recurrent Molecular Genetics and Epigenetics Abnormity in T Lymphoblastic Lymphoma / Leukemia -Review

T lymphoblastic lymphoma / leukemia is a strong invasive and has a high incidence of various molecular genetic abnormalities. The NOTCH1 / FBXW7 mutation is one of the most common mutations, and related with good prognosis in T-LBL / ALL. PTEN mutation, a poor prognostic factor, could be overcome by NOTCH1 mutations in pediatric patients to some extent. Patients with MLL gene abnormality and loss of heterozygosity 6q have worse prognosis than those with normal karyotype. The incidence of MLL gene abnormality, RUNX1 mutation and DNMT3A mutation in early precursor T-lymphoblastic leukemia was higher than that of other mature subtypes, which could be used as risk stratification factors. Epigenetic abnormalities play an important role in the malignant transformation of stem cells. Epigenetics treatment such as demethylation therapy may improve the prognosis of high-risk patients. In this article, the NOTCH1,FBXW7,PTEN and RAS gene mutations and prognosis, the molecular and cellular abnormalities and prognosis, as well as epigenetic abnormality and prognosis are reviewed.

TRIB2 regulates normal and stress-induced thymocyte proliferation

TRIB2, a serine/threonine pseudokinase identified as an oncogene, is expressed at high levels in the T-cell compartment of hematopoiesis. The proliferation of developing thymocytes is tightly controlled to prevent leukemic transformation of T cells. Here we examine Trib2 loss in murine hematopoiesis under steady state and proliferative stress conditions, including genotoxic and oncogenic stress. Trib2−/− developing thymocytes show increased proliferation, and Trib2−/− mice have significantly higher thymic cellularity at steady state. During stress hematopoiesis, Trib2−/− developing thymocytes undergo accelerated proliferation and demonstrate hypersensitivity to 5-fluorouracil (5-FU)-induced cell death. Despite the increased cell death post 5-FU-induced proliferative stress, Trib2−/− mice exhibit accelerated thymopoietic recovery post treatment due to increased cell division kinetics of developing thymocytes. The increased proliferation in Trib2−/− thymocytes was exacerbated under oncogenic stress. In an experimental murine T-cell acute lymphoblastic leukemia (T-ALL) model, Trib2−/− mice had reduced latency in vivo, which associated with impaired MAP kinase (MAPK) activation. High and low expression levels of Trib2 correlate with immature and mature subtypes of human T-ALL, respectively, and associate with MAPK. Thus, TRIB2 emerges as a novel regulator of thymocyte cellular proliferation, important for the thymopoietic response to genotoxic and oncogenic stress, and possessing tumor suppressor function.

Dermoid cyst of the pancreas

Context Cystic lesions of the pancreas constitute a wide spectrum of entities ranging from non-neoplastic to malignant neoplastic lesions. Dermoid cysts (cystic teratoma) are uncommon benign, well-differentiated germ cell lesions. Teratomas can be divided into mature and immature subtypes. Mature cystic teratoma is commonly found in the ovary. The pancreas is extremely rare as primary site. Case report A 59-year-old asymptomatic man in a follow-up for occupational exposure to asbestos was submitted to chest computed tomography (CT): incidentally evidenced a left sub-diaphragmatic expansive lesion. Physical examination and laboratory tests were normal. Abdominal ultrasound (US) evidenced a partial cystic mass located in the anterior para-renal space in continuity with the pancreatic tail. The duct of Wirsung was regular. Abdominal CT and magnetic resonance imaging (MRI) showed an 80×60×40 mm hypodense lesion in the pancreatic tail, partly solid and partly fluid. No signs of non resectability or metastases were found. The patient was submitted to robotic-assisted surgery. The cyst originated from the pancreatic tail and only a small portion of the pancreatic tail was removed. The post-operative course was regular and the patient was discharged on post-operative day eight. Macroscopic examination displayed a cyst with smooth walls containing sebaceous material. Histology showed an intrapancreatic cyst lined with typical, focally keratinized, stratified squamous epithelium with sebaceous glands in the underlying stroma, surrounded by intense lymphoid infiltrate with germinal centers. The diagnosis was dermoid cyst of the pancreas. Conclusion Clinical presentation of pancreatic dermoid cyst is not specific and occurs preferably in younger ages. Symptoms range from an asymptomatic palpable mass to obstructive jaundice, abdominal pain, back pain, vomiting, anorexia, weight loss; some cases are diagnosed occasionally. Dermoid cyst of the pancreas is a true cyst. Differential diagnosis of lesions that mimic cystic neoplasm of the pancreas is still difficult. US, CT and MRI may be helpful, but there are no pathognomonic data for preoperative identification. The robotic surgery allows to perform challenging pancreatic resections.

LMO2 expression reflects the different stages of blast maturation and genetic features in B-cell acute lymphoblastic leukemia and predicts clinical outcome

LMO2 is highly expressed at the most immature stages of lymphopoiesis. In T-lymphocytes, aberrant LMO2 expression beyond those stages leads to T-cell acute lymphoblastic leukemia, while in B cells LMO2 is also expressed in germinal center lymphocytes and diffuse large B-cell lymphomas, where it predicts better clinical outcome. The implication of LMO2 in B-cell acute lymphoblastic leukemia must still be explored. We measured LMO2 expression by real time RT-PCR in 247 acute lymphoblastic leukemia patient samples with cytogenetic data (144 of them also with survival and immunophenotypical data) and in normal hematopoietic and lymphoid cells. B-cell acute lymphoblastic leukemia cases expressed variable levels of LMO2 depending on immunophenotypical and cytogenetic features. Thus, the most immature subtype, pro-B cells, displayed three-fold higher LMO2 expression than pre-B cells, common-CD10+ or mature subtypes. Additionally, cases with TEL-AML1 or MLL rearrangements exhibited two-fold higher LMO2 expression compared to cases with BCR-ABL rearrangements or hyperdyploid karyotype. Clinically, high LMO2 expression correlated with better overall survival in adult patients (5-year survival rate 64.8% (42.5%-87.1%) vs. 25.8% (10.9%-40.7%), P= 0.001) and constituted a favorable independent prognostic factor in B-ALL with normal karyotype: 5-year survival rate 80.3% (66.4%-94.2%) vs. 63.0% (46.1%-79.9%) (P= 0.043). Our data indicate that LMO2 expression depends on the molecular features and the differentiation stage of B-cell acute lymphoblastic leukemia cells. Furthermore, assessment of LMO2 expression in adult patients with a normal karyotype, a group which lacks molecular prognostic factors, could be of clinical relevance.

Ovarian carcinoma cells influence differentiation of Lin−CD45RA− dendritic cell precursors into two mature subtypes in vitro

Objective Decreased number and impaired function of dendritic cells (DCs) have been found in ovarian carcinoma microenvironment. The study was designed to detect if this phenomenon was associated with abnormal DC differentiation influenced by ovarian carcinoma cells. Materials and methods FLT-3L and SCF were used for expanding DC precursors from CD34+ progenitors. GM-CSF and TNF-α were used to induce mature DCs. Supernatants of cultured ovarian carcinoma cell line SKOV3 were added, in order to study their influence on the differentiation and maturation of Lin−CD45RA− DC precursors. Flow cytometry was used to analyze cell subtypes and molecular surface markers. Allogeneic T-cell proliferation assay was used to exam stimulatory activity of DCs. IL-12 secretion was tested by ELISA. Results Lin−CD45RA− DC precursors cultured with GM-CSF and TNF-α generated HLA-DR+CD11C+CD123− myeloid DCs (mDCs) and HLA-DR+CD11C−CD123+ plasmacytoid DCs (pDCs) in vitro. The supernatants from ovarian carcinoma cell line SKOV3 (SKOV3-supernatants) increased pDCs and decreased mDCs compared with pure medium or supernatants of normal ovarian surface epithelial (OSE) cells. There were no significantly different expressions of HLA-DR and CD80 by DCs between with and without SKOV3-supernatants. But DCs treated with SKOV3-supernatants were shown to have impaired immune activity to stimulate proliferation of allogeneic CD3+ T cells and secrete IL-12. Conclusion Ovarian carcinoma cells influence differentiation of Lin−CD45RA− DC precursors into subtypes of mature DCs in vitro. This resulted in fewer mDCs, increased number of pDCs, and impairment of mature DCs immune activity.

Accumulation of gallium-67 within mature and immature teratoma in pediatric patients: investigation for the uptake mechanism

We encountered cases of mature and immature teratoma with positive uptake of (67)Ga. The objective of this study is to investigate the mechanism of (67)Ga accumulation within mature and immature teratomas by comparing the findings of gallium scan, computed tomography (CT), and autoradiography of surgical specimens with the pathological findings. The subjects comprised 14 children who underwent surgical resection for intra-abdominal mature and immature teratomas, which were histologically proved to be of the mature and immature subtype. Their age ranged from 24 days to 14 years. The origins of the mature teratomas consisted of seven ovaries including one bilateral case, two retroperitoneal, and two sacrococcygeal regions. The origins of the immature teratomas were retroperitoneum in two cases, an ovary and a sacrococcygeal region. Complete surgical excision was feasible in all children. They underwent both gallium scan and CT prior to surgery. Single-photon emission computed tomography was added in some cases. For two gallium-positive cases, radiography and scintigraphy (autoradiography) of the resected specimen were performed. Of the 14 children, 5 (one with immature and four with mature subtype) showed positive (67)Ga uptake within tumors, which originated from the retroperitoneum in the 3 boys, and from the ovary in the 2 girls. All had typical CT findings of teratoma, including calcifications, fat components, cystic areas, and solid parts. (67)Ga accumulation in the four mature teratomas appeared discretely strong, and was considered to correspond with intralesional calcifications. However, in the remaining one immature teratoma, the gallium distribution was diffuse within the tumor. The comparison between radiography and autoradiography of the resected mature teratomas confirmed the correlation between the intralesional calcifications and areas of (67)Ga accumulation. A high-uptake ratio of (67)Ga in benign teratoma was indicated. A close correlation between gallium scan and CT helps to ascertain whether (67)Ga uptake results from malignant and/or immature elements, or mature tissue components.