Methylseleninic Acid Sensitizes Ovarian Cancer Cells to T-Cell Mediated Killing by Decreasing PDL1 and VEGF Levels

Redox active selenium (Se) compounds at sub toxic doses act as pro-oxidants with cytotoxic effects on tumor cells and are promising future chemotherapeutic agents. However, little is known about how Se compounds affect immune cells in the tumor microenvironment. We demonstrate that the inorganic Se compound selenite and the organic methylseleninic acid (MSA) do not, despite their pro-oxidant function, influence the viability of immune cells, at doses that gives cytotoxic effects in ovarian cancer cell lines. Treatment of the ovarian cancer cell line A2780 with selenite and MSA increases NK cell mediated lysis, and enhances the cytolytic activity of T cells. Increased T cell function was observed after incubation of T cells in preconditioned media from tumor cells treated with MSA, an effect that was coupled to decreased levels of PDL1, HIF-1α, and VEGF. In conclusion, redox active selenium compounds do not kill or inactivate immune cells at doses required for anti-cancer treatment, and we demonstrate that MSA enhances T cell-mediated tumor cell killing via PDL1 and VEGF inhibition

Comprehensive mapping of the effects of azacitidine on DNA methylation, repressive/permissive histone marks and gene expression in primary cells from patients with MDS and MDS-related disease

Azacitidine (Aza) is first-line treatment for patients with high-risk myelodysplastic syndromes (MDS), although its precise mechanism of action is unknown. We performed the first study to globally evaluate the epigenetic effects of Aza on MDS bone marrow progenitor cells assessing gene expression (RNA seq), DNA methylation (Illumina 450k) and the histone modifications H3K18ac and H3K9me3 (ChIP seq). Aza induced a general increase in gene expression with 924 significantly upregulated genes but this increase showed no correlation with changes in DNA methylation or H3K18ac, and only a weak association with changes in H3K9me3. Interestingly, we observed activation of transcripts containing 15 endogenous retroviruses (ERVs) confirming previous cell line studies. DNA methylation decreased moderately in 99% of all genes, with a median beta-value reduction of 0.018; the most pronounced effects seen in heterochromatin. Aza-induced hypomethylation correlated significantly with change in H3K9me3. The pattern of H3K18ac and H3K9me3 displayed large differences between patients and healthy controls without any consistent pattern induced by Aza. We conclude that the marked induction of gene expression only partly could be explained by epigenetic changes, and propose that activation of ERVs may contribute to the clinical effects of Aza in MDS.Peer reviewe

Coagulation and inflammation in experimental endotoxemia in vitro and in vivo : Monitoring method and effects of nicotinamide

In gram negative sepsis, endotoxin from the bacterial membrane elicits proinflammatory and procoagulant host responses. Sepsis and its frequent complication disseminated intravascular coagulation (DIC) are leading causes of morbidity and mortality in the intensive care. A pivotal mechanism in the pathogenesis of DIC is the expression of tissue factor (TF) on circulating monocytes after endotoxin encounter. Activation of the cascade systems of coagulation and inflammation can lead to a rapid deterioration in e.g. sepsis with procoagulant changes and microthromboses, resulting in DIC and multi organ failure. Monitoring of the degree of coagulation activation, to discover changes before clinical exacerbation, is critical. We have established a global monitoring method for coagulation activity, clotting onset time (COT), based on free oscillating rheometry. The assay design mimicks the natural blood milieu, as the method is based on CaC12 repletion of blood or plasma, adding no artificial activators or inhibitors. The COT method proved to be a quick and reliable test, able to detect hypoand hypercoagulation. It also showed promising results as a bedside monitoring method, able to detect the transient activation of coagulation caused by intravenous injection of endotoxin to healthy volunteers. We also demonstrate that the COT method is sensitive even to small changes in the amount of endotoxin induced monocyte surface TF. In neurotrauma patients, COT was a predictor of prognosis for the patients. This observation, however, is difficult to interpret and requires further investigation. The vitamin B derivative nicotinamide was assessed for its potential modulating effects on endotoxin induced activation of coagulation and inflammation. Nicotinamide is a known PARP inhibitor. PARP is necessary for activation of the transcription factor NFkappabeta, responsible for transcription of many genes involved in the response to endotoxin, e.g. proinflammatory cytokines, giving a rationale for a potential beneficial effect of nicotinamide in endotoxemia. We demonstrate that nicotinamide is a potent inhibitor of three major endotoxin induced proinflammatory cytokines, Il-1 beta, IL-6 and IL-8, in addition to the previously known TNFalpha inhibiting effect. However, the dose dependent inhibition of endotoxin induced proinflammatory responses was shown unlikely to be due to PARP inhibition. In endotoxin stimulated leukocyte suspensions as well as in whole blood, nicotinamide caused a dose dependent decrease of monocyte TF expression, describing a previously unknown inhibitory effect of nicotinamide on the procoagulant changes associated with endotoxemia. We have also demonstrated that the decrease of monocyte TF expression is at least partly caused by shedding from the monocyte surface. Our conclusion is that nicotinamide may have a therapeutic potential in modulating conditions associated with activation of coagulation and inflammation, such as in sepsis and DIC

Epigenetic Modifiers in Myeloid Malignancies: The Role of Histone Deacetylase Inhibitors

Myeloid hematological malignancies are clonal bone marrow neoplasms, comprising of acute myeloid leukemia (AML), the myelodysplastic syndromes (MDS), chronic myelomonocytic leukemia (CMML), the myeloproliferative neoplasms (MPN) and systemic mastocytosis (SM). The field of epigenetic regulation of normal and malignant hematopoiesis is rapidly growing. In recent years, heterozygous somatic mutations in genes encoding epigenetic regulators have been found in all subtypes of myeloid malignancies, supporting the rationale for treatment with epigenetic modifiers. Histone deacetylase inhibitors (HDACi) are epigenetic modifiers that, in vitro, have been shown to induce growth arrest, apoptotic or autophagic cell death, and terminal differentiation of myeloid tumor cells. These effects were observed both at the bulk tumor level and in the most immature CD34+38− cell compartments containing the leukemic stem cells. Thus, there is a strong rationale supporting HDACi therapy in myeloid malignancies. However, despite initial promising results in phase I trials, HDACi in monotherapy as well as in combination with other drugs, have failed to improve responses or survival. This review provides an overview of the rationale for HDACi in myeloid malignancies, clinical results and speculations on why clinical trials have thus far not met the expectations, and how this may be improved in the future

Epigenetic Modifiers in Myeloid Malignancies: The Role of Histone Deacetylase Inhibitors

Myeloid hematological malignancies are clonal bone marrow neoplasms, comprising of acute myeloid leukemia (AML), the myelodysplastic syndromes (MDS), chronic myelomonocytic leukemia (CMML), the myeloproliferative neoplasms (MPN) and systemic mastocytosis (SM). The field of epigenetic regulation of normal and malignant hematopoiesis is rapidly growing. In recent years, heterozygous somatic mutations in genes encoding epigenetic regulators have been found in all subtypes of myeloid malignancies, supporting the rationale for treatment with epigenetic modifiers. Histone deacetylase inhibitors (HDACi) are epigenetic modifiers that, in vitro, have been shown to induce growth arrest, apoptotic or autophagic cell death, and terminal differentiation of myeloid tumor cells. These effects were observed both at the bulk tumor level and in the most immature CD34+38− cell compartments containing the leukemic stem cells. Thus, there is a strong rationale supporting HDACi therapy in myeloid malignancies. However, despite initial promising results in phase I trials, HDACi in monotherapy as well as in combination with other drugs, have failed to improve responses or survival. This review provides an overview of the rationale for HDACi in myeloid malignancies, clinical results and speculations on why clinical trials have thus far not met the expectations, and how this may be improved in the future

Living with systemic mastocytosis : Balancing between vulnerability and resilience: A qualitative study

Purpose: Systemic mastocytosis is a rare group of haematological malignancies with heterogeneous symptoms from various organs, and an overall survival that ranges from normal for indolent SM (ISM) to 2-4 years for advanced SM subtypes (Adv SM). The purpose of this study was to describe the experiences of everyday life among persons diagnosed with ISM or Adv SM. Methods: In this qualitative study, data were collected through purposive sampling and semi-structured interviews with 16 participants diagnosed with ISM (n = 9) or Adv SM (n = 7). Data were subsequently analysed with content analysis. Results: Three main categories were identified. The persistent presence of the disease includes findings of how the symptoms affected the participants and how they handled its limitations and the adaptions and medication management required. Struggling against ignorance illustrates contacts with both healthcare professionals and strangers. The participants described being forced to be experts on SM due to a general lack of knowledge. An illness or wellness perspective encompasses the participants' feelings of vulnerability and alienation, but also how various strategies were used to gain emotional control. Conclusions: The disease has considerable impact on everyday life, with constant efforts required to manage symptoms and medication side effects. The complexity and rarity of the disease complicated relationships with healthcare professionals and contributed to feelings of marginalisation and alienation. The participants described feeling vulnerable, but used a multitude of strategies in their striving for resilience. Trusting relationships with healthcare professionals, family members and friends promoted a wellness perspective

Clinical Outcomes of Adults with Systemic Mastocytosis: A 15-Year Multidisciplinary Experience

Systemic mastocytosis (SM) is a rare, clonal, clinically heterogeneous disorder of the mast cells (MCs), and mainly affects adults. The present study aims to describe the clinical and laboratory features as well as the outcomes of SM. A 15-year retrospective study was conducted on 195 consecutive SM patients (aged ≥ 18 years) diagnosed in 2006–2020 at the Multidisciplinary Mastocytosis Center at Karolinska University Hospital. Patients with indolent SM (ISM) represented the most common SM variant (88.2%). Furthermore, the frequencies of aggressive SM and SM with associated non-mast-cell hematological neoplasm were 4.1% and 7.7%, respectively. The prevalence of SM in the adult population of the Stockholm region was estimated to be 10.6/100,000 inhabitants, and the mean incidence of SM cases in the Stockholm region was 0.77/100,000 people per year. In this series, tryptase levels were below 20 ng/mL in 51 patients (26%). Osteoporosis was present in 21.9% of all cases. Interestingly, there was no progression from ISM to advanced SM variants in our study. Furthermore, overall survival was significantly better in ISM patients compared to advanced SM patients (p < 0.0001). Our data suggest that the early recognition and correct diagnosis of SM has prognostic significance

Localization-Specific Expression of CCR1 and CCR5 by Mast Cell Progenitors

Mast cells are powerful immune cells found predominately in barrier tissues. They play an important role in immune surveillance and act as effector cells in allergic reactions. Mast cells develop from mast cell progenitors (MCp), which migrate to the peripheral tissues via the blood circulation. Presumably, the homing of MCp to the peripheral sites and localization is regulated by chemotactic signals. Due to the scarce abundance of these cells, chemotactic receptors have not been previously characterized on primary MCp. Here, mRNA transcripts for CCR1 and CX(3)CR1 were identified in mouse bone marrow and lung MCp in a gene expression screen of chemotactic receptors. However, surface expression of CCR1 was only found in the bone marrow MCp. Flow cytometry-based screening identified distinct surface expression of CCR5 by mouse peritoneal mast cells and MCp, while surface expression of CXCR2-5, CX(3)CR1, CCR1-3, CCR6-7, and CCR9 was not detected. Low surface expression of CCR5 was detected in mouse MCp in the bone marrow, spleen, and lung. To translate the findings to human, blood and bone marrow MCp from healthy donors were analyzed for possible CCR1 and CCR5 expression. Human MCp showed distinct surface expression of both CCR1 and CCR5. The expression levels of these chemokine receptors were higher in human bone marrow MCp than in the peripheral blood, suggesting that CCR1 and CCR5 may mediate retention in the bone marrow. In conclusion, mouse and human MCp show differential expression of CCR1 and CCR5 depending on their localization