Periodontitis associated with plasminogen deficiency: a case report

BACKGROUND: Plasminogen deficiency is a rare autosomal recessive disease, which is associated with aggressive periodontitis and gingival enlargement. Previously described treatments of plasminogen deficiency associated periodontitis have shown limited success. This is the first case report indicating a successful therapy approach consisting of a non-surgical supra- and subgingival debridement in combination with an adjunctive systemic antibiotic therapy and a strict supportive periodontal regimen over an observation period of 4 years. CASE PRESENTATION: The intraoral examination of a 17-year-old Turkish female with severe plasminogen deficiency revealed generalized increased pocket probing depths ranging from 6 to 9 mm, bleeding on probing over 30%, generalized tooth mobility, and gingival hyperplasia. Alveolar bone loss ranged from 30% to 50%. Clinical attachment loss corresponded to pocket probing depths. Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola, Prevotella intermedia, Prevotella nigrescens and Eikenella corrodens have been detected by realtime polymerase chain reaction. Periodontal treatment consisted of full mouth disinfection and adjunctive systemic administration of amoxicillin (500 mg tid) and metronidazole (400 mg tid). A strict supportive periodontal therapy regimen every three month in terms of supra- and subgingival debridement was rendered. The reported therapy has significantly improved periodontal health and arrested disease progression. Intraoral examination at the end of the observation period 3.5 years after non-surgical periodontal therapy showed generalized decreased pocket probing depths ranging from 1 to 6 mm, bleeding on probing lower 30%, and tooth mobility class I and II. Furthermore, microbiological analysis shows the absence of Porphyromonas gingivalis, Prevotella intermedia and Treponema denticola after therapy. CONCLUSION: Adjunctive antibiotic treatment may alter the oral microbiome and thus, the inflammatory response of periodontal disease associated to plasminogen deficiency and diminishes the risk of pseudomembrane formation and progressive attachment loss. This case report indicates that patients with plasminogen deficiency may benefit from non-surgical periodontal treatment in combination with an adjunctive antibiotic therapy and a strict supportive periodontal therapy regimen.published_or_final_versio

A Novel murine model identifies cooperating mutations and therapeutic targets critical for chronic myeloid leukemia progression

The introduction of highly selective ABL-tyrosine kinase inhibitors (TKIs) has revolutionized therapy for chronic myeloid leukemia (CML). However, TKIs are only efficacious in the chronic phase of the disease and effective therapies for TKI-refractory CML, or after progression to blast crisis (BC), are lacking. Whereas the chronic phase of CML is dependent on BCR-ABL, additional mutations are required for progression to BC. However, the identity of these mutations and the pathways they affect are poorly understood, hampering our ability to identify therapeutic targets and improve outcomes. Here, we describe a novel mouse model that allows identification of mechanisms of BC progression in an unbiased and tractable manner, using transposon-based insertional mutagenesis on the background of chronic phase CML. Our BC model is the first to faithfully recapitulate the phenotype, cellular and molecular biology of human CML progression. We report a heterogeneous and unique pattern of insertions identifying known and novel candidate genes and demonstrate that these pathways drive disease progression and provide potential targets for novel therapeutic strategies. Our model greatly informs the biology of CML progression and provides a potent resource for the development of candidate therapies to improve the dismal outcomes in this highly aggressive disease.Work in the Huntly laboratory is funded by CRUK, The European Research Council (ERC), Leukaemia Lymphoma Research, the Kay Kendall Leukaemia Fund, Wellcome Trust, the Medical Research Council (UK), the Leukemia Lymphoma Society America and the Cambridge NIHR Biomedical Research centre. David Adams is funded by Cancer Research UK and Wellcome Trust. Steffen Koschmieder has received funding from Deutsche José Carreras Leukämie-Stiftung (DJCLS; grant 10/23).This is the final published version. It first appeared at http://dx.doi.org/10.1084/jem.2014166

Acadesine Kills Chronic Myelogenous Leukemia (CML) Cells through PKC-Dependent Induction of Autophagic Cell Death

CML is an hematopoietic stem cell disease characterized by the t(9;22) (q34;q11) translocation encoding the oncoprotein p210BCR-ABL. The effect of acadesine (AICAR, 5-Aminoimidazole-4-carboxamide-1-β-D-ribofuranoside) a compound with known antileukemic effect on B cell chronic lymphoblastic leukemia (B-CLL) was investigated in different CML cell lines. Acadesine triggered loss of cell metabolism in K562, LAMA-84 and JURL-MK1 and was also effective in killing imatinib-resistant K562 cells and Ba/F3 cells carrying the T315I-BCR-ABL mutation. The anti-leukemic effect of acadesine did not involve apoptosis but required rather induction of autophagic cell death. AMPK knock-down by Sh-RNA failed to prevent the effect of acadesine, indicating an AMPK-independent mechanism. The effect of acadesine was abrogated by GF109203X and Ro-32-0432, both inhibitor of classical and new PKCs and accordingly, acadesine triggered relocation and activation of several PKC isoforms in K562 cells. In addition, this compound exhibited a potent anti-leukemic effect in clonogenic assays of CML cells in methyl cellulose and in a xenograft model of K562 cells in nude mice. In conclusion, our work identifies an original and unexpected mechanism by which acadesine triggers autophagic cell death through PKC activation. Therefore, in addition to its promising effects in B-CLL, acadesine might also be beneficial for Imatinib-resistant CML patients

Nuclear factor-κB is constitutively activated in primitive human acute myelogenous leukemia cells

Abstract Human acute myelogenous leukemia (AML) is thought to arise from a rare population of malignant stem cells. Cells of this nature, herein referred to as leukemic stem cells (LSCs), have been documented for nearly all AML subtypes and appear to fulfill the criteria for stem cells in that they are self-renewing and give rise to the cells found in many leukemic populations. Because these cells are likely to be critical for the genesis and perpetuation of leukemic disease, the present studies sought to characterize unique molecular properties of the LSC population, with particular emphasis on the transcription factor, nuclear factor-κB (NF-κB). Previous experiments have shown that unstimulated human CD34+ progenitor cells do not express NF-κB. In contrast, primary AML CD34+ cells display readily detectable NF-κB activity as assessed by electrophoretic mobility shift assay and gene expression studies. Furthermore, detailed analyses of enriched AML stem cells (CD34+/CD38−/CD123+) indicate that NF-κB is also active in the LSC population. Given the expression of NF-κB in leukemic, but not normal primitive cells, the hypothesis that inhibition of NF-κB might induce leukemia-specific apoptosis was tested by treating primary cells with the proteasome inhibitor MG-132, a well-known inhibitor of NF-κB. Leukemic CD34+/CD38− cells displayed a rapid induction of cell death in response to MG-132, whereas normal CD34+/CD38− cells showed little if any effect. Taken together, these data indicate that primitive AML cells aberrantly express NF-κB and that the presence of this factor may provide unique opportunities to preferentially ablate LSCs.</jats:p

Report of a symposium on: diagnosis and treatment of cutaneous head and neck melanoma

A series of presentations and discussions was held during a symposium on the diagnosis and treatment of cutaneous head and neck melanoma. The purpose of this meeting was to define certain guidelines on diagnosis and treatment of head and neck melanoma. The results of this symposium are summarized and condensed in this report. Recommendations are made for diagnostic strategies and for treatment. It is indicated that research efforts in immunology need to be expanded to develop rational immunotherap

Bcl-2 Inhibitor ABT-263 Targets Oxidative Phosphorylation and Selectively Eradicates Quiescent Human Leukemia Stem Cells

Abstract Abstract 206 Targeting leukemia stem cells (LSCs) is a priority for the development of improved therapeutic regimens. However, the intrinsic heterogeneity of malignant populations in acute myelogenous leukemia (AML) has made it challenging to identify biological properties appropriately conserved amongst primitive cell types. To better characterize physiological features of LSCs related to growth and survival, we previously investigated oxidative state and demonstrated that the majority of functionally-defined LSCs are characterized by relatively low levels of reactive oxygen species (termed “ROS-low”)(Lagadinou et al, abstract 639 ASH 2011). Based on these findings herein we have used primary AML specimens and flow cytometric sorting for endogenous ROS levels so as to enrich for ROS-low LSCs, and we have characterized mechanisms controlling LSC energy production and redox state. We report here that LSC-enriched ROS-low cells are metabolically dormant tumor populations characterized by low levels of oxygen–dependent mitochondrial respiration (OXPHOS), low rates of anaerobic glycolysis, and a low overall cellular ATP content. These properties are unique for LSCs, as bulk leukemic cells and non-tumorigenic ROS-high cells were found to be significantly more metabolically active with regard to both aerobic and anaerobic types of energy production. Intriguingly, we further demonstrate that in contrast to bulk leukemic cells, ROS-low subsets are deficient in their ability to utilize glycolysis when mitochondrial respiration is pharmacologically blocked, indicating a paradoxical dependence of LSCs on mitochondrial energy production. To investigate the mechanisms that underlie the distinct metabolic properties of ROS-low cells, we performed gene expression studies using RNA-seq based methods. In agreement with an important role of mitochondrial metabolism in LSCs we found several mitochondrial-related genes up-regulated in ROS-low cells. Importantly, we found that ROS-low cells express significantly higher levels of bcl-2 both at the mRNA and protein level. To determine if bcl-2 up-regulation relates to the metabolic status of ROS-low cells, we evaluated the bio-energetic profile of bulk AML cells and isolated ROS-low subsets +/− in vitro treatment with the bcl-2 pharmacologic inhibitor ABT-263 and the closely related compound ABT-737. We found that functional inhibition of bcl-2 by this class of drugs results in severe OXPHOS blockage both in total AML cells and ROS-low subsets, indicating a novel non-canonical activity of bcl-2 in promoting AML cell mitochondrial bioenergetics. In unfractionated total AML cells, the bcl-2-inhibitor initiated impairment of OXPHOS was associated with a robust induction of glycolysis and variable toxicity, indicating glycolysis as a compensatory protective response of leukemic cells in this class of drugs. In contrast, bcl-2 inhibition and OXPHOS impairment in ROS-low cells was not compensated by glycolysis, and resulted in depletion of cellular ATP levels, elimination of cellular glutathione pool, oxidation and profound toxicity in the LSC-enriched ROS-low compartment in vitro. Taken together, these studies indicated ABT-263 as an approach to eradicate LSCs by impairing fundamental aspects of LSC metabolism. To more directly investigate this issue we performed xenograft analyses. We first treated ROS-low AML populations in vitro with ABT-263 concentrations equal to the IC50 concentration of the total AML cells for each sample, and then transplanted treated vs. vehicle control cells into immune deficient NSG mice. We found that ABT-263 reduced LSC potential in all AML specimens evaluated by this functional assay. Next, we treated mice engrafted with primary human AML cells with ABT-737 in vivo (50mg/kg IP for 15d), and then performed serial transplantation analyses with the engrafted cells from treated and control mice. These functional studies showed that ABT-737 clearly reduced leukemia burden in the treated primary recipients, and also significantly reduced the capacity of engrafted leukemia cells to establish AML in secondary recipients. Based on these findings, our studies propose a model wherein the unique physiology of ROS-low LSCs provides an opportunity for selective targeting via disruption of Bcl-2-dependent oxidative phosphorylation. Disclosures: No relevant conflicts of interest to declare. </jats:sec