Epigenetic Therapy Research Articles

Contingent Synergistic Interactions between Non-Coding RNAs and DNA-Modifying Enzymes in Myelodysplastic Syndromes.

Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal hematopoietic stem cell disorders with maturation and differentiation defects exhibiting morphological dysplasia in one or more hematopoietic cell lineages. They are associated with peripheral blood cytopenias and by increased risk for progression into acute myelogenous leukemia. Among their multifactorial pathogenesis, age-related epigenetic instability and the error-rate DNA methylation maintenance have been recognized as critical factors for both the initial steps of their pathogenesis and for disease progression. Although lower-risk MDS is associated with an inflammatory bone marrow microenvironment, higher-risk disease is delineated by immunosuppression and clonal expansion. "Epigenetics" is a multidimensional level of gene regulation that determines the specific gene networks expressed in tissues under physiological conditions and guides appropriate chromatin rearrangements upon influence of environmental stimulation. Regulation of this level consists of biochemical modifications in amino acid residues of the histone proteins' N-terminal tails and their concomitant effects on chromatin structure, DNA methylation patterns in CpG dinucleotides and the tissue-specific non-coding RNAs repertoire, which are directed against various gene targets. The role of epigenetic modifications is widely recognized as pivotal both in gene expression control and differential molecular response to drug therapies in humans. Insights to the potential of synergistic cooperations of epigenetic mechanisms provide new avenues for treatment development to comfort human diseases with a known epigenetic shift, such as MDS. Hypomethylating agents (HMAs), such as epigenetic modulating drugs, have been widely used in the past years as first line treatment for elderly higher-risk MDS patients; however, just half of them respond to therapy and are benefited. Rational outcome predictors following epigenetic therapy in MDS and biomarkers associated with disease relapse are of high importance to improve our efforts in developing patient-tailored clinical approaches.

Therapeutic targeting of histone lysine demethylase KDM4B blocks the growth of castration-resistant prostate cancer

Epigenetics is an emerging mechanism for tumorigenesis. Treatment that targets epigenetic regulators is becoming an attractive strategy for cancer therapy. The role of epigenetic therapy in prostate cancer (PCa) remains elusive. Previously we demonstrated that upregulation of histone lysine demethylase KDM4B correlated with the appearance of castration resistant prostate cancer (CRPC) and identified a small molecular inhibitor of KDM4B, B3. In this study, we further investigated the role of KDM4B in promoting PCa progression and tested the efficacy of B3 using clinically relevant PCa models including PCa cell line LNCaP and 22Rv1 and xenografts derived from these cell lines. In loss and gain-functional studies of KDM4B in PCa cells, we found that overexpression of KDM4B in LNCaP cells enhanced its tumorigenicity whereas knockdown of KDM4B in 22Rv1 cells reduced tumor growth in castrated mice. B3 suppressed the growth of 22Rv1 xenografts and sensitized tumor to anti-androgen receptor (AR) antagonist enzalutamide inhibition. B3 also inhibited 22Rv1 tumor growth synergistically with rapamycin, leading to cell apoptosis. Comparative transcriptomic analysis performed on KDM4B knockdown and B3-treated 22Rv1 cells revealed that B3 inhibited both H3K9me3 and H3K27me3 demethylase activities. Our studies establish KDM4B as a target for CRPC and B3 as a potential therapeutic agent. B3 as monotherapy or in combination with other anti-PCa therapeutics offers proof of principle for the clinical translation of epigenetic therapy targeting KDMs for CRPC patients.

The impact of early-life environment on absence epilepsy and neuropsychiatric comorbidities.

This review discusses the long-term effects of early-life environment on epileptogenesis, epilepsy, and neuropsychiatric comorbidities with an emphasis on the absence epilepsy. The WAG/Rij rat strain is a well-validated genetic model of absence epilepsy with mild depression-like (dysthymia) comorbidity. Although pathologic phenotype in WAG/Rij rats is genetically determined, convincing evidence presented in this review suggests that the absence epilepsy and depression-like comorbidity in WAG/Rij rats may be governed by early-life events, such as prenatal drug exposure, early-life stress, neonatal maternal separation, neonatal handling, maternal care, environmental enrichment, neonatal sensory impairments, neonatal tactile stimulation, and maternal diet. The data, as presented here, indicate that some early environmental events can promote and accelerate the development of absence seizures and their neuropsychiatric comorbidities, while others may exert anti-epileptogenic and disease-modifying effects. The early environment can lead to phenotypic alterations in offspring due to epigenetic modifications of gene expression, which may have maladaptive consequences or represent a therapeutic value. Targeting DNA methylation with a maternal methyl-enriched diet during the perinatal period appears to be a new preventive epigenetic anti-absence therapy. A number of caveats related to the maternal methyl-enriched diet and prospects for future research are discussed.

Abstract B027: The transcription factor HIF2alpha partakes in the differentiation block of acute myeloid leukemia

Abstract Acute myeloid leukemia (AML) is characterized by epigenetic silencing of differentiation genes and accumulation of aberrant myeloid cells arrested at different stages of myeloid development. The combination of epigenetic and differentiation therapies represents an attractive opportunity for AML patients by promoting chromatin remodeling at differentiation genes and induction of terminal maturation and leukemia debulking. The aim of our work is to define the function of the hypoxia inducible transcription factor HIF2alpha in the pathogenesis of AML. By its genetic inactivation and pharmacological inhibition in AML cell lines and patient-derived xenograft models, we found that HIF2alpha acts as a novel regulator of the AML differentiation block and promotes leukemia progression. Gene expression profiling of HIF2alpha-dependent transcriptome revealed that HIF2alpha mainly promotes the expression of genes involved in transcriptional modulation and epigenetic modifications, whilst inhibiting genes of myeloid maturation and activation. Mechanistically, inhibition of HIF2alpha results in decreased global levels of the heterochromatin marker H3K27me3, which is specifically deposited by the catalytic subunit EZH2 of the Polycomb repressive complex 2. Intriguingly, we found that HIF2alpha and EZH2 cooperate at favoring EZH2-mediated deposition of H3K27me3 at reverse hypoxia responsive elements in the regulatory regions of myeloid maturation genes. Additionally, we demonstrate that HIF2alpha is positively regulated by the pro-differentiation agent all-trans retinoic acid (ATRA), and its inhibition cooperates with ATRA in triggering AML cell differentiation. In conclusion, we provide new mechanistic insights into the role of HIF2alpha in the pathogenesis of AML, by promoting an undifferentiated state via EZH2-mediated epigenetic silencing of myeloid differentiation genes. Importantly, small molecule inhibitors of HIF2alpha have been recently generated and are tested for solid cancers. Therefore, HIF2alpha inhibition may open new therapeutic avenues for AML patients and add therapeutic value to ATRA-based therapies by interrupting HIF2alpha upregulation and promoting an epigenetic state permissive to maturation of leukemic blasts and leukemia exhaustion. Citation Format: Daniela Magliulo, Carolina Caserta, Serena Belluschi, Cristina Fracassi, Kety Giannetti, Raffaella Pini, Ettore Zapparoli, Stefano Beretta, Eleonora Draghi, Marco J. Morelli, Raffaella Di Micco, Bernhard Gentner, Luca Vago, Rosa Bernardi. The transcription factor HIF2alpha partakes in the differentiation block of acute myeloid leukemia. [abstract]. In: Proceedings of the AACR Special Conference: Cancer Epigenomics; 2022 Oct 6-8; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2022;82(23 Suppl_2):Abstract nr B027.

Novel epigenetic therapy for Th17cell mediated autoimmune inflammatory diseases.

Immunopathogenesis leads to autoimmune and inflammatory diseases of many organs with variable clinical manifestations. The eye can be seriously affected. A common ocular autoimmune complication, autoimmune uveitis, can lead to irreversible blindness. Currently the first line treatment for autoimmune uveitis is corticosteroids.1 However, some patients do not respond to steroids. Some steroid treated patients may developed systemic and ocular side effects such as osteoporosis, cataract and glaucoma.

Abstract B007: Endogenous retrotransposable elements induction in SMARCA4-deficient ovarian cancer is associated with immunomodulatory changes in the tumor microenvironment

Abstract Introduction: Ovarian cancer (OC) is the most lethal gynecologic cancer, and there is an urgent need to develop new therapies. Patient responses to immune checkpoint blockade have overall been disappointing, which is likely due to the immunosuppressive tumor microenvironment (TME) of most OCs that may be in part under the influence of epigenetic regulation. There is evidence that OCs that harbor loss-of-function mutations in the SWI/SNF chromatin remodeling complex catalytic subunit, SMARCA4, may be more immunogenic and amenable to immunotherapy, however the mechanisms by which this occurs is unclear. Proposed mechanisms include de-methylation of normally silenced noncoding elements. The aim of our study is to investigate the epigenetic changes of retrotransposable elements (RTEs) induced by SMARCA4 mutations that modulate the TME. Experimental Procedures: Stable isogenic SMARCA4-knockout (KO) murine (ID8) and human (OAW28) OC models were generated using CRISPR-Cas9 lentiviral transduction and clonal selection. Transcriptomic analyses of these cells were performed using RNA sequencing using ribosomal depletion protocol and validated using qRT-PCR. Moreover, differentially expressed coding genes in RNA sequencing were identified according to fold change between KO and control cells of RPKM (Reads Per Kilobase of transcript, per Million mapped reads) values. Gene Ontology enrichment analysis was then performed to identify the most altered pathways. Results: CRISPR-Cas9 KO of SMARCA4 in OC cells led to an increased fraction of reads coming from repetitive elements (repeatome). Within the repeatome, short interspersed nuclear elements (SINEs) have increased fraction of mapped reads in KO compared to wildtype OAW28 cells. Quantification analyses of known repeats demonstrate significant upregulation of endogenous retroviruses (ERVs) in KO compared to control ID8 cells. Certain RTEs known to be associated with viral mimicry and increased immunogenicity were upregulated in KO cells. Top 10 upregulated genes were significantly enriched in pathways related to interferon and viral responses. Further quantification analyses demonstrated that the dsRNA sensing pathway was activated in SMARCA4-deficient OCs leading to downstream increase in interferon-response genes. Knockdown of dsRNA sensor mitochondrial antiviral signaling protein (MAVS) downregulates the SMARCA4 loss-induced interferon-response activation. Conclusion: De-repression of normally silenced RTEs and subsequent increased immunogenicity of SMARCA4-deficient OCs suggest a potential new immunomodulatory biomarker for targeted therapy investigation. A mechanistic understanding of the role of SMARCA4 in OCs enhances our knowledge of the epigenetic processes that govern immune-stimulating responses in the TME. Studies are underway to explore combination epigenetic therapy and immunotherapy in these cancers. Citation Format: Melica N. Brodeur, Siyu Sun, Yingjie Zhu, Benjamin Greenbaum, Britta Weigelt, Dmitriy Zamarin. Endogenous retrotransposable elements induction in SMARCA4-deficient ovarian cancer is associated with immunomodulatory changes in the tumor microenvironment. [abstract]. In: Proceedings of the AACR Special Conference: Cancer Epigenomics; 2022 Oct 6-8; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2022;82(23 Suppl_2):Abstract nr B007.

Prader-Willy syndrome: heterogenous genetic mechanisms in a wide phenotypic spectrum

Prader-Willi syndrome (PWS) is an imprinted neuro-behavioral syndrome, affecting many organ systems, characterized by severe hypothalamic-pituitary dysfunction, severe hypotonia, feeding difficulties in the neonatal period, followed by hyperphagia with gradual development of morbid obesity since early childhood, short stature, hypogonadism, infertility, characteristic facial features, impaired motor and language development, cognitive impairment of varying degrees, delayed speech, increased risk of developing autism spectrum disorders (ASD), impaired social skills, and behavioral problems and / or severe psychiatric problems. Loss of expression of the preferentially paternally expressed of genes from the chromosomal region 15q11-q13 are the basis of pathogenesis of PWS, which occur through several mechanisms: deletion of 5-6 Mb DNA fragment from the 15q11-q13 region of the inherited paternal chromosome (65-75%), maternal uniparental disomy (mUPD) (in 20-30%) and Imprinting center (IC) defects, as microdeletions and epimutations (in 1-4%). In this paper, we present two cases diagnosed with PWS from our experience. The importance of diagnosis and familial recurrence risk will be discussed, as well as genotype-phenotype relationships in PWS. Patients with PWS should benefit from multidisciplinary management very early for greatly improving their quality of life, taking into consideration that obesity is a major factor influencing morbidity and mortality. In addition, a better understanding of the molecular basis of PWS pathogenesis offers hope for the development of new, revolutionary, epigenetic therapies in PWS, as well as in other genetic imprinting diseases.

Epigenetic therapy reprograms M2-type tumor-associated macrophages into an M1-like phenotype by upregulating miR-7083-5p.

Reprogramming M2-type, pro-tumoral tumor-associated macrophages (TAMs) into M1-type, anti-tumoral macrophages is a key strategy in cancer therapy. In this study, we exploited epigenetic therapy using the DNA methylation inhibitor 5-aza-2'-deoxycytidine (5-aza-dC) and the histone deacetylation inhibitor trichostatin A (TSA), to reprogram M2-type macrophages into an M1-like phenotype. Treatment of M2-type macrophages with the combination of 5-aza-dC and TSA decreased the levels of M2 macrophage cytokines while increasing those of M1 macrophage cytokines, as compared to the use of either therapy alone. Conditioned medium of M2 macrophages treated with the combination of 5-aza-dC and TSA sensitized the tumor cells to paclitaxel. Moreover, treatment with the combination inhibited tumor growth and improved anti-tumor immunity in the tumor microenvironment. Depletion of macrophages reduced the anti-tumor growth activity of the combination therapy. Profiling of miRNAs revealed that the expression of miR-7083-5p was remarkably upregulated in M2 macrophages, following treatment with 5-aza-dC and TSA. Transfection of miR-7083-5p reprogrammed the M2-type macrophages towards an M1-like phenotype, and adoptive transfer of M2 macrophages pre-treated with miR-7083-5p into mice inhibited tumor growth. miR-7083-5p inhibited the expression of colony-stimulating factor 2 receptor alpha and CD43 as candidate targets. These results show that epigenetic therapy upon treatment with the combination of 5-aza-dC and TSA skews M2-type TAMs towards the M1-like phenotype by upregulating miR-7083-5p, which contributes to the inhibition of tumor growth.

Analysis of the Epigenetic Mechanism and Treatment of Huntington’s Disease

Huntington’s disease (HD) is an irreversible neurodegenerative disorder that is inherited in an autosomal dominant manner. In HD, many regions of the human brain are affected, including the striatum, thalamus, and cortex. The mechanism is by the expansion of CAG repeats, which encode glutamine (Q) in the Huntingtin gene on chromosome 4p16.3. Patients with more CAG repeats tend to have a younger age of onset and a higher risk. Mutant HTT protein, translated from mtHtt, would congregate or interact with other proteins, causing damage to the human body. Patients with HD show symptoms like chorea, which is an involuntary motor disability, cognitive deterioration, and psychiatric disturbances. Except for the genetic pathology of HD, the epigenetic mechanism of this disease has made a lot of progress in recent years. This paper primarily focuses on the alternation of deoxyribonucleic acid (DNA) methylation, histone modification, and non-coding ribonucleic acids (ncRNAs) in HD as well as the advancements of epigenetic therapy and healthcare in HD.

Pembrolizumab in Combination with Epigenetic Therapy Is Safe and Active in Heavily Treated Patients with Peripheral T-Cell Lymphoma (PTCL) and Cutaneous T-Cell Lymphoma (CTCL): Preliminary Results from the Embolden Trial

Background: Peripheral T-cell lymphomas (PTCLs) are uniquely sensitive to epigenetic modifiers. Our group previously demonstrated that combinations of epigenetic modifiers such as histone deacetylase inhibitors (HDACi), hypomethylating agents and pralatrexate produced potent synergy in pre-clinical models of PTCL, which produced compelling activity in early phase clinical studies. We have demonstrated that epigenetic modifiers, such as decitabine and 5-azacytidine (Marchi et al; Br. J. Haematol. 171, 2015) induces the expression of cancer testis antigens and established that pralatrexate acts as an immunomodulatory agent affecting genes involved in cytokine production, viral response and apoptosis. These pre-clinical data suggest a role for the incorporation of the immune-checkpoint inhibitor, pembrolizumab, to epigenetic backbones. Herein, we report on the differential clinical activity of adding the immune checkpoint inhibitor, pembrolizumab, to decitabine, pralatrexate, or the combination and we describe the role of cytokines as a biomarker of treatment response. Trial Design & Methods: This is a phase 1b study of pembrolizumab combined with pralatrexate alone (Arm A), with pralatrexate + decitabine (Arm B), or decitabine alone (Arm C) in patients with relapsed and refractory PTCL and CTCL. A standard 3+3 dose-escalation was applied in the doublet Arms (A and C) while a DLT-adapted partial order continual reassessment method (POCRM) for dose-finding with combinations of agents was applied in the triplet Arm (Arm B). We evaluated the cytokine profile using a Luminex-based immunoassay on serum samples obtained from trial patients on days 1, 8 and 15 during cycle 1 of treatment. Quantitative changes in 25 unique cytokines were evaluated, and these changes were correlated with clinical outcomes. Results: We enrolled 15 patients with six patients in Arm A, four in Arm B, and five in Arm C. All patients that received at least one dose of drug were evaluable for toxicity. One dose limiting toxicity (DLT) was observed in Arms A and B (grade 3 thrombocytopenia and febrile neutropenia, respectively). In Arm C, three DLTs were observed including one patient with grade 3 hyponatremia and rash; one patient with grade 4 thrombocytopenia, neutropenia, and anemia; and one patient with grade 4 neutropenia. There were no treatment related deaths. Nine patients out of 15 were evaluable for response at the time of this analysis. Of these nine evaluable patients, one achieved a complete remission (Arm B), two achieved partial remission (1 in Arm A, 1 in Arm B), one had stable disease (Arm C), and five experienced disease progression (2 in Arm A, 1 in Arm B, and 2 in Arm C). Interestingly, two of the three responses were seen in patients who received the triplet of pralatrexate, decitabine, and pembrolizumab (Arm B) and one response was seen in a patient treated with pralatrexate and pembrolizumab (Arm A). The serum cytokine profile revealed significant changes in only five of the 25 cytokines surveyed. Of the five cytokines, three pro-inflammatory cytokines, TNFα, MIP-3α and IL-10, measured at day 1 pre-treatment exhibited significantly higher levels (p= 0.0001, 0.0008 and 0.003 respectively) compared to healthy controls. Trial patients who responded to treatment (PR/CR) in either Arms demonstrated a decline in serum levels of TNFα and IL-10 by day 15 of cycle 1, whereas non-responders (PD/SD) showed stable to increased levels of both TNFα (Figure 1) and IL-10. Conclusion: These preliminary data suggest that the integration of pembrolizumab into an epigenetic backbone is safe and demonstrates encouraging responses in heavily pretreated patients with PTCL and CTCL. Pharmacodynamic data suggests that certain cytokines might have predictive value as biomarkers of disease response and progression. Interestingly, patients that responded (PR/CR) to the study drugs displayed a decline in cytokine levels, highlighting the prognostic implications of these cytokines. Additional pharmacodynamic studies, including flow cytometry of peripheral blood mononuclear cells, and pharmacokinetic studies are ongoing. Clinical trial registry NCT03240211. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Early Effects of a Repurposed Therapeutic PB-04 in Beta Thalassemia Intermedia and in Transgenic Sickle Mice

Background: Biochemical, epidemiologic, genetic, and clinical data over 7 decades have shown that renewed or persistent expression of fetal globin reduces clinical severity in beta-thalassemias (BTI) and hemoglobinopathies (sickle cell disease, SCD). Hydroxyurea (HU) and epigenetic therapies which act through HDAC and DNMT-1 inhibition have demonstrated beneficial clinical activity; butyrate, a Class I HDAC inhibitor which suppresses BCL11A, increased HbF by 3-fold and total hemoglobin (Hb) by 1 gm/dl in SCD and eliminated transfusions in beta thalassemia patients, and decitabine strongly induces HbF, increases total Hb, and reduces biomarkers of sickling. Active erythropoiesis, basal EPO levels, available iron, and select mutations or modifiers are associated with responses. Additional small molecule therapies, especially those with additive activity with HU, are considered desirable for many patients world-wide. Methods: Seeking oral noncytotoxic therapeutic candidates with low development risks, we utilized a high-throughput screen with a gamma globin promoter-reporter and cytotoxicity readout for unrecognized fetal globin-inducing activity in libraries of all FDA- and EMA-approved or clinical stage therapeutics (for any medical indication). PB-04, a candidate with a benign long-term safety profile (used to inhibit L-dopa metabolism in Parkinson's disease), does not inhibit proliferation of erythroid progenitors and suppresses or displaces 4 repressors of the fetal globin gene promoter, BCL11A, HDAC3, KLF1, LSD-1, indicating targeted molecular activity. PB-04 has additive effects with HU in inducing F-cells in sickle cell erythroid progenitors. PB-04 was evaluated in 3 predictive animal models and in 3 escalating dose cohorts in adult subjects with BTI. Results: In 3 animal models, PB-04 increased fetal globin mRNA by 12-to 20-fold and F-cells by 20% in anemic baboons, F-cells and mean Hb F/cell by 2 to 7-fold in beta-YAC mice, and fetal globin mRNA by 1.8-fold and % F-cells by 2.4-fold without toxicity in Townes SCD mice, similar to the changes induced by HU (both given 5 days/wk for 4 wks). In six beta thalassemia (BTI) subjects who completed ten 12-week courses at 1, 3, or 5 mg/kg doses given once/day, 3 times/wk, increases from baseline in F-reticulocytes (mean 5.2-fold, range 1.5-15.7), F-cells, (mean 4.4-fold, range 2.3 to 7.3-fold), and HbF/cell (MFI), (mean 6.6-fold, range 3 to 11.3-fold), were observed (p<0.03 for all parameters). Increases were observed even in subjects with low baseline HbF levels. HbF increases by HPLC were 2.7 to 14%. Treatment emergent adverse effects (TEAEs) have been Gr 1-2 and largely transient in these subjects receiving 12 weeks' therapy. Other dosing regimens are being investigated. Conclusions: Initial studies in beta globin disorders indicate PB-04 induces fetal globin protein expression assayed by F-reticulocytes, F-cells, and mean HbF/cell in BTI patients and in transgenic SCD mice without toxicity. These findings indicate PB-04, which has complementary activity to all the approved SCD therapeutics, merits clinical evaluation in patients with sickle cell disease.

High Prevalence of Epigenetic Mutations in Histiocytic and Dendritic Cell Disorders: Results from Molecular Analysis of a Large Cohort from Histiocytosis Working Group

Introduction Over the last decade, recurrent oncogenic alterations in the MAPK/ERK pathway have been discovered in various histiocytic and dendritic cell disorders, especially Erdheim-Chester disease (ECD), Langerhans cell histiocytosis (LCH), and Rosai-Dorfman disease (RDD). These discoveries have led to the successful use of targeted BRAF- and MEK-inhibitors. However, most data are derived from small institutional studies mostly focusing on ECD and LCH, which leaves room for a comprehensive evaluation of the molecular underpinnings in a large cohort. Methods Formalin-fixed paraffin embedded tumor biopsies from various histiocytic/dendritic cell disorders seen at a tertiary institution from 2001-2021 were subjected to whole exome sequencing (WES) using one of two assays: in-house SureSelectXT AllExon V5+UTR or commercially available Tempus xT assay. Identified variants were filtered to remove polymorphic, low coding impact and low read coverage variants. A variant was then selected for further analysis if it met one of the following criteria: 1) observed as somatic in ≥1 tumor-germline pairs or COSMIC database or 2) observed in at least three samples with an allele frequency of ≥10% in ≥1 sample. Cases were clustered into mutually exclusive groups based on their primary driver mutational profile using the following funneling order: BRAF-V600E (BRAF-V600E mutations), BRAF*/NRAS/KRAS (BRAF non-V600E, KRAS, or NRAS mutations), CSF1R (CSF1R mutations), MAPK (MAPK/MEK mutations), and PI3K (AKT3, INPP4B, MTOR, PIK3CA, PIK3R1, PIK3R2, PIK3R3, PPP2R1A, MTR mutations). A cancer specific pathway enrichment was performed on the unknown cases, which identified epigenetic mutations as major pathway alterations observed in the cohort. We also correlated the presence of epigenetic mutations with clinical features and outcomes. Results We included 114 cases with histiocytic and dendritic cell disorders in the study. Median age at diagnosis was 51y (IQR 37-64). The disease distribution was as follows: 46 LCH, 20 ECD, 17 RDD, 8 follicular dendritic cell sarcoma (FDCS), 1 adult xanthogranuloma, 12 malignant histiocytosis (MH; including histiocytic and Langerhans cell sarcoma), and 10 multicentric reticulohistiocytosis (MRH). Based on the known driver mutations in histiocytoses, the following 5 molecular groups were identified: BRAF-V600E (n= 19, 17%), BRAF*/KRAS/NRAS (n=17, 15%), MAPK (n=14, 12%), PI3K (n=8, 7%), CSF1R (n=2, 2%) (Figure 1). A large proportion (n=48, 42%) did not have any of the known driver mutations, while 6 cases (5%) had no alterations identified. Cancer-specific enrichment analysis in the entire cohort revealed mutations in epigenetic genes in 47 (41%) cases, including 30 (26%) cases with identifiable driver mutations and 17 (15%) cases without known driver mutations. Median number of epigenetic mutations was 1 (range 1-11); 21% cases had 2 and 10% cases had 3 epigenetic mutations, respectively. The most common epigenetic mutations included those in KMT2C (34%), KMT2D (23%), and ARID1A (19%). The mutational groups with highest prevalence of epigenetic mutations were CSF1R (100%), MAPK (71%), and PI3K (63%), while lowest prevalence of these alterations was found in BRAF-V600E group (16%; p=0.0003). The epigenetic gene mutations were seen more commonly in MRH (90%) and MH (50%) compared with ECD (45%), RDD (41%), FDCS (38%), and LCH (33%; p=0.037). There was no association between epigenetic gene mutations and age at diagnosis or organ involvement. The median overall survival (OS) was not significantly different between those with epigenetic mutations and those without such alterations (22y vs. 17y, p=0.89). Conclusions In this large study of patients with diverse histiocytic and dendritic cell disorders, we found a high prevalence of mutations in epigenetic genes (41%). These mutations were specifically enriched in tumors with non-BRAF-V600E mutations, and in MRH/MH. These data shed light on additional mechanisms of disease pathogenesis, and with available epigenetic therapies, warrant further investigation. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Durable Clinical Impacts and Mechanisms of Action and Resistance in EZH1/2-Targeting Epigenetic Therapy

Background: Epigenomes allow the rectification of disordered gene expressions, thereby providing new targets for pharmacological interventions in cancer therapy. The clinical utility of targeting histone H3 lysine tri-methylation (H3K27me3) as an epigenetic hallmark has been demonstrated. However, in actual therapeutic settings, the mechanism by which H3K27me3-targeting therapies exert their effects and the response of tumor cells remain unclear. Results and Discussion: We conducted intensive molecular monitoring of three patients enrolled in the valemetostat first-in-human phase 1 clinical trial (NCT02732275) for adult T-cell leukemia/lymphoma (ATL). Valemetostat was administered orally once daily (200 mg/day) until a sign of disease progression could be observed. The number of abnormal lymphocytes (Ably) in these three patients drastically decreased after one week of treatment. All patients could stay on valemetostat single agent for more than 2 years with acceptable safety and durable response. PBMC samples (n = 55) were collected from these three patients immediately before (Pre) and during treatment, as well as during the progressive disease (PD) stage. Flow cytometry-based histone methylation assay demonstrated that tumor H3K27me3 level was generally high in the Pre-samples, but the valemetostat treatment reduced it to a normal level in all patients. In addition, ChIP sequencing (ChIP-seq) could directly assess how valemetostat affects the tumor epigenome. The pre-treatment tumor cells showed an overall increasing trend in H3K27me3. For all H3K27me3 peaks (51,683 peaks), 85.9% of the peak signals decreased at the average fold-change of 0.742 after the valemetostat treatment. Focusing on the gene loci, an overall decrease could be observed around the TSS and across the gene body. The characteristic H3K27me3 clusters initially observed in the tumor cells were demethylated. We also conducted integrative multilayered single-cell analyses (scATAC-seq and scRNA-seq) and showed that valemetostat abolishes the highly condensed chromatin structure formed by the plastic H3K27me3 and neutralizes multiple gene loci, such as tumor suppressor genes (TSGs), in all patients. These results demonstrated that valemetostat sufficiently restored the epigenome of the tumor cells close to the healthy state, leading to clinical improvements. Although all tested cases showed a durable response for more than 2 years, these responses were eventually interrupted due to the recurrence of ATL. We identified characteristic somatic mutations of EZH2 during clonal repopulation at PD. The identified amino acid substitutions were all located at the interface between EZH2 and valemetostat. Direct evaluation of the H3K27me3 level in the PD sample harboring the acquired EZH2 mutation showed that tumor cells in a hypermethylated state were repopulating. The scATAC-seq analysis also showed strong chromatin compaction of the same gene set occurred in the rapidly propagating resistant clone, indicating that the clonally selected mutations should be responsible for resistance. In patients free of the EZH2 resistant mutations, we detected TET2 mutation or elevated DNMT3A expression in the propagated resistant clones. Genome-wide DNA methylation analysis revealed increased DNA methylation near the TSS in the resistant clones. The genes characterized by the H3K27me3-related chromatin condensation were restored by valemetostat treatment but were again strongly re-condensed by mCpG gain at PD. Consequently, the gene regulation of several important TSGs restored by valemetostat was repressed again. Furthermore, in the single-cell platform, we successfully identified subpopulations with distinct metabolic and gene translation characteristics implicated in primary susceptibility until the acquisition of the heritable (epi)mutations. Conclusion: This study illustrates, for the first time, the molecular and cellular dynamics in patients in response to a molecular-targeting inhibitor designed for histone methyltransferases. Eliminating H3K27me3 leads to the reprogramming of the cancer epigenome, thereby exerting a sustained benefit on tumors. Targeting chromatin homeostasis might provide opportunities for further sustained epigenetic therapies.

A Real World Experience of Combined Treatment with Romidepsin and Azacitidine in Patients with Peripheral T-Cell Lymphoma - a Bridge to Transplant and an Effective Salvage for the Unfit

Introduction Patients with peripheral T cell lymphoma (PTCL) lack good treatment options, particularly in the relapsed and refractory setting (Mak V et al. J Clin Oncol 2013). The development of the targeted therapies in PTCL has been lagging behind those developed for B cell lymphomas. Our work suggested that combination of epigenetic therapies could be a safe and effective approach in PTCL, particularly in T cell lymphomas with follicular helper phenotype (Marchi E et al. Br. J Haematol 2015; O'Connor AO et al; Blood 2019; Falchi L et al. Blood 2020). This could be explained by the presence of recurrent mutations in epigenetic factors, including Ten-Eleven Translocation-2 (TET2), DNA methyl transferase-3A (DNMT3A), and isocitrate dehydrogenase-2 (IDH2). that specifically clusters in PTCL (Couronné L. et al. N Eng J Med 2012; Lemonnier F et al. Blood 2012). Despite these observations, a direct link between presence of the mutations and sensitivity to treatment remain to be established. Objectives To evaluate the merits of romidepsin plus azacitidine in patients with PTCL when administered in a 'real-world’ scenario (both subcutaneous and oral azacytidine). Our phase 2 study of oral azacitidine in combination with romidepsin showed remarkable results and we wanted to evaluate the efficacy of these two drugs in patients who were not enrolled on a clinical study for following reasons: 1) Rarity of PTCL prevents wide availability of clinical studies for this patient population; 2) Enrollment criteria, including performance status, prevent enrollment of all patients who are too frail but could possibly benefit from this treatment; 3) Second synchronous or recent malignancies. Methods We retrospectively identified PTCL patients that were treated with azacitidine and romidepsin outside of a clinical trial based upon queries regarding off study use. The study was reviewed and approved by each Medical Center Institutional Review Board. We have identified 26 patients world-wide and these patients were treated using 4 different schedules: Schedule A: azacitidine 75mg/m2 s.c. on days 1-7, romidepsin 14 mg/m2 on day 1, 8 and 15 of a 28 day cycle (total of 7 patients); Schedule B: azacitidine 75mg/m2 s.c. on days 1-5, romidepsin 14 mg/m2 on day 8, 15 and 22 of a 35 day cycle; Schedule C (6 patients): azacitidine 75mg/m2 s.c. on days 1-7, romidepsin 12-14 mg/m2 on day 8, 15 and 22 of a 28 day cycle (6 patients); and Schedule D (as per Falchi L. et al. Blood 2020, 7 patients). Results In our retrospective analysis we have identified 18 patients who had angioimmunoblastic lymphoma (AITL), 2 with adult T-cell leukemia/lymphoma (ATLL), 3 with TFH PTCL, 1 with PTCL-NOS and 2 with composite lymphoma (TFH PTCL with diffuse large B cell lymphoma and ALK- ALCL with FL). Twelve of the 26 patients had next generation sequencing performed. Most common mutations found were those of TET2 (8 pts), RHOA (4pts), IDH2 (3pts) and DNMT3A (2 pts). Among these 26 patients, overall response rate (ORR) was 73% and the complete response rate (CR) was 53%. Median number of cycles was 3.5 (range 1-12). Treatment was well tolerated and notable adverse effects included nausea, fatigue, rash, neutropenia and thrombocytopenia. One patient experienced febrile neutropenia while another had pulmonary infiltrates (drug toxicity vs. infection). Thrombocytopenia was the most common reason for dose reduction of romidepsin (to 12mg/m2) or its omission on day 8, 15 or 22. Median OS and PFS were not reached and 13.3 months respectively (Figure 1). Median DOR was not reached. In 8 patients, azacitidine and romidepsin were used to achieve remission prior to stem cell transplant (1 auto, 7 allo), with all 7 patients were in CR at their last disease assessment. One patient died of transplant related mortality 8 months after his allogeneic stem cell transplant. Conclusion Subcutaneous azacitidine and romidepsin administered in a 'real-world’ situation is highly effective in patients with relapsed PTCL with tolerable toxicity, and can be used to successfully bridge patients to stem cell transplant and to treat frail patients that would not be candidate for enrollment in clinical trials.. Notably, the efficacy was similar to the one reported on a clinical study with oral azacitidine and romidepsin. A randomized phase 2B trial of romidepsin and oral azacitidine versus investigator's choice in patients with R/R PTCL is currently ongoing and open to enrollment (NCT04747236). Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Promising Safety and Efficacy Results from an Ongoing Phase 1b Study of Pembrolizumab Combined with Decitabine in Patients with Relapsed/Refractory (R/R) Acute Myeloid Leukemia (AML)

BACKGROUND: For AML patients (pts) deemed ineligible for intensive cytotoxic chemotherapy, hypomethylating agents (HMA) have been established as standard treatment. Decitabine 20 mg/m2 on days 1-10 per 28 day cycle has demonstrated single agent efficacy with 15% complete remission (CR)/CR with incomplete hematologic recovery (CRi) in R/R AML (Khan et al. Leuk Lymphoma 2017). In a phase 2 trial, 10-day decitabine with venetoclax demonstrated overall response rate (ORR) of 62% in R/R AML (Dinardo C et al. Lancet Haematol 2020). However, aberrant upregulation of PDL1 and PD-L2 has been observed in 25% and 33% of CD34+ samples from AML pts respectively (Plass C et al. Semin Oncol 2008). Pts resistant to epigenetic therapy had relative higher increments in gene expression of PD-L1, PD-L2 and CTLA4 compared with pts who achieved response, suggesting that PD-1 signaling may be involved in resistance mechanisms to HMA. In a prior phase 2 trial evaluating pembrolizumab and azacitidine in R/R AML, responses among 29 evaluable pts demonstrated ORR 17.2% (Gojo I et al. Blood 2019). In this phase 1b trial, we set out to test the combination of pembrolizumab and decitabine (NCT03969446). METHODS: Pts [≥18 years old (yo); ECOG ≤1] with R/R AML not eligible for allogeneic hematopoietic cell transplantation (alloHCT), received decitabine 20 mg/m2 on days 1-10. If in CR/CRi, decitabine was reduced to days 1-5 of cycles 3+. Pembrolizumab was given on days 1 and 22 in all cycles. Cycle length was 42 days. This phase 1b study has two arms, AML and myelodysplastic syndromes (MDS) with primary objectives of safety, tolerability, recommended phase 2 dose (RP2D) and to obtain preliminary estimates of CR/CRi rate using the "3+3" design. Here, we provide interim safety and efficacy data for the first 6 pts on the AML arm. RESULTS: As of July 1, 2022, 6 pts were enrolled to the AML arm cohort 1. The six treated and evaluable pts received a median of 2 (range: 1-7) cycles of treatment. At baseline, the median age was 78 yo (range: 72-81) with median 2 (range: 1-4) prior lines of regimens, and median 35% (7-65) bone marrow blasts. All pts had previously progressed on decitabine and venetoclax. All-non-hematologic grade 3 toxicities were reversible. No dose limiting toxicity, ≥ gr4 non-hematologic toxicity, or treatment related deaths were seen. Most common Grade (Gr) 3-4 treatment-related hematologic toxicities were: anemia (100%), febrile neutropenia (83%), lymphopenia (100%), and thrombocytopenia (100%). Most common infectious toxicities included Gr 3 lung infections (50%). Three pts (50%) achieved CR/CRi, 1 pt (16.7%) achieved partial remission, and 2 pts (33%) achieved stable disease. ORR was 66.7% in this cohort. The median follow-up time is 19.8 months (4.1-22.6), with 4 pts still alive at the data cut -off. One pt was able to bridge to alloHCT. CONCLUSIONS: The combination of pembrolizumab and decitabine in the AML arm cohort 1 of this study in pts with R/R AML was deemed safe with manageable side effect profile and encouraging anti-leukemic activity and offers potential for promising therapy for R/R AML that progress even after prior HMA therapy. Furthermore, this study demonstrates the effectiveness of the 10-day decitabine schedule. The study is now open for the MDS arm, with treatment of the same schedule of pembrolizumab in combination with decitabine 20 mg/m2 on days 1-5 of each cycle. The study has also been amended to include AML cohort 2 to add venetoclax to the decitabine/pembrolizumab regimen and pts are now being enrolled on this arm.

High Throughput Epigenomic Mapping of Hematopoietic Stem and Progenitor Cells Using Low Cell Input Acoustic Enhanced Immunoprecipitation

Acute myeloid leukemia (AML) is a complex disease with several etiologies characterized by incomplete cellular differentiation and clonal proliferation of hematopoietic stem and progenitor cells (HSPCs) in place of normal hematopoiesis. Non-mutational epigenetic reprogramming is an emerging hallmark and enabling characteristic of cancer pathogenesis. Epigenetic regulation of gene activity is an essential component of chromatin stability and maintenance of proper cellular function and differentiation. Modifications of gene and histone landscape methylation and acetylation, three-dimensional chromatin structure, and protein-controlled activating and silencing switches are all regulated by epigenetic components, and thus are integral to understanding gene regulatory mechanisms during cell fate changes, disease onset, progression, as well as for optimizing therapeutic regime. In addition, this information holds immense potential for accurate identification of disease biomarkers, cell of origin, and targets for epigenetic therapy. However, existing chromatin immunoprecipitation sequencing (ChIP-Seq) workflows require significant cellular material and are very time-consuming, requiring cumbersome optimization. Moreover, cellular heterogeneity can influence accuracy of results from the perspective of sample preparation efficiency and also population-biased effects. Both normal and malignant bone marrow are heterogeneous in cell type and stage of differentiation that leads to imprecise results with regard to epigenetic determinates. In our study, we implemented Covaris's Adaptive Focused Acoustics® (AFA®) technology to miniaturize sample volumes for both chromatin shearing and immunoprecipitation in a 96-well format. This approach enables a standardized, robust, automatable, half-day workflow for both ChIP and Hi-ChIP applications. AFA ChIPseq- was applied to flow sorted hematopoietic stem and progenitor cells (HSPC) from individual mice. We utilized a range of epitopes including major histone modifications (H3K9me1/2/3, H3K27ac) and factors (CTCF, cohesin). Interestingly, we found epitope-dependent differences in AFA-enhanced binding with CTCF saturating at 30 minutes, whereas H3K27ac required 4 hours of AFA pulse to facilitate chromatin binding. Additionally, we evaluated low input in vitro and in vivo samples, with limited dilution of lineage negative HSPCs ranging from 500,000 to 5,000 cells with comparable sheared chromatin yield and immunoprecipitated material. Overlap of peaks called by MACS2 was consistent among the various cell inputs as well as when compared with gold standard CTCF ChIPseq- data previously performed on pooled samples from our previously published work. The low cell input capability permitted deconvolution of dynamic epigenetic changes in protein binding and chromatin structure during normal lineage specification of hematopoietic stem cells. Epigenetic remodeling of these sites was consistent with established gene programs essential for myeloid differentiation. Data were found to be in alignment with standard ChIPseq- and Hi-C datasets generated from similar cell populations. The simplified and significantly shortened (Hi)ChIP-seq processes showcased in this study will be highly beneficial for both research and clinical diagnostic applications owing to their requirements for using 96-well plate format and their ability to become integrated into automated workflows. Taken together, this technology and workflow represents a high throughput epigenetic system for small cell numbers of cells with a multitude of applications enabling laboratories focused in cell biology and translational research.

The Frida Study: An Option for Mutated FLT3 Relapsed/Refractory Acute Myeloid Leukemia Patients with a Novel Iadademstat and Gilteritinib Combination Therapy

Background: Epigenetic dysregulation is a hallmark of acute myeloid leukemia (AML) and is caused by recurrent translocations and/or mutations in chromatin regulators and transcription factors, resulting in myeloid differentiation blockade and leukemic stem cell renewal. Accordingly, about 70% of recurring mutations in AML patients target regulators of gene expression, underscoring the potential of epigenetic therapies to change the natural history of the disease. Iadademstat (iada/ORY-1001) is a specific, oral, potent, covalent inhibitor of the epigenetic Lysine-Specific Demethylase 1 (LSD1/KDMA1) enzyme. Preclinical models demonstrate that exposure to iada decreases leukemic stem cell survival and preclinical and clinical studies shows iada's effect on inducing macrophage/monocytic differentiation of blast cells. Furthermore, a Phase 2 ongoing study of iada in combination with azacitidine (ALICE) shows high complete remission (CR)/ CR with incomplete count recovery (CRi) and durable responses in treatment naïve, unfit AML patients (pts) without exacerbating the toxicity profile of azacitidine (Salamero et al., Abstract P586 EHA 2022). Despite improvements in AML therapy, relapses remain a common challenge, contributing to the death of more than 50% of pts, particularly in those subpopulations with higher risk genetics, the largest of which (up to 30-40% of AML pts) harbor mutations in the fms-like tyrosine kinase 3 (FLT3) gene. Use of the FLT3 inhibitor (FLT3i) gilteritinib as monotherapy for relapsed/refractory (R/R) pts has resulted in improved outcomes but the duration of remission achieved is transient and often brief. The Phase 3 randomized ADMIRAL trial of gilteritinib revealed a CR rate of 20%; and an event-free-survival (EFS) of 2.8 months (Perl, et al., NEJM 2019). Preclinically, iada produces marked synergy with FLT3i, including gilteritinib, in FLT3 wild-type and mutated (FLT3 mut+) AML cells and in derived cell lines resistant to venetoclax, azacitidine and other FLT3is. The novel MOAs generating this synergy of the combination include activation of a pro-differentiative epigenetic and transcriptional program with simultaneous suppression of the activity of MYC target genes (Yashar, et al. 2022, https://doi.org/10.1101/2022.01.17.476469). The FRIDA clinical trial is designed to establish the safety, tolerability of the combination of iada plus gilteritinib and to identify the recommended phase 2 dose (RP2D) in FLT3 mut+ R/R AML specifically according to FDA's Project Optimus. Methods: Adult pts with body weight ≥50 Kg and ECOG 0-2, with FLT3 mut+ R/R AML, after 1 or 2 prior lines of therapy, will be enrolled. Up to 18 pts, in a 3+3 escalation phase, will receive iada at doses of 75 to 150 ug, orally, in 5 days ON - 2 days OFF schedule, with continuous gilteritinib, at 120 mg/day orally. In the expansion phase, up to 14 pts at the selected safe and pharmacologically active dose/s (determined based on all available data from escalation pts including PK, target engagement (TE), safety, tolerability, and emerging activity) will be enrolled. TE will be assessed with a proprietary validated chemo-probe assay for LSD1 occupancy in PBMCs. Primary endpoints of the study are safety and RP2D determination, based on the same 5 criteria outlined above. Bayesian posterior probability efficacy monitoring will be performed periodically for each dose cohort starting from the first 6 additional pts in the expansion phase (total of 12). Bayesian efficacy futility and early stopping boundary will be applied during the monitoring. Posterior probability criterion (Prob (θ>0.3) ≥ 0.60) at the end of the study will warrant additional development. The safety of the combination treatment will be also continuously evaluated during expansion following a Bayesian design stopping rule. Secondary endpoints include overall survival, EFS, CR, CR/CR with partial hematologic recovery (CRh), overall response rates, time to response, duration of response, and transfusion rate. Exploratory endpoints include measurable residual disease and gene mutational analysis. Pts who achieve a response can undergo hematopoietic stem cell transplant. The study plans to have 15 sites enrolling in the US. Additional sites will be added for a subsequent randomized controlled double-blinded FRIDA 2 study to assess the efficacy of the iada and gilteritinib combination in R/R FLT3 mut+ AML.

Long-Term Outcomes of Patients Aged 65 Years or Older with Peripheral T-Cell Lymphoma, Not Otherwise Specified (PTCL-NOS) and T-Follicular Helper T-Cell Lymphoma (TFHTCL) Treated with Curative Intent CHOP(like) Chemotherapy

Introduction CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) remains the standard treatment for older adults with non-anaplastic large cell lymphoma (ALCL), nodal peripheral T-cell lymphomas (PTCLs). However, recent studies suggest that patients (pts) > 75 years (y) have similar outcomes with CHOP compared to those receiving palliative regimens (Ellin et al. Hematological Oncology 2017). In addition, with studies demonstrating sensitivity of PTCLs to epigenetic therapies, especially in the T-follicular helper (TFH) subtypes, there are emerging clinical trials evaluating these agents in newly diagnosed PTCL patients > 60 y (NCT02232516). We evaluated the long-term outcomes of pts aged 65 y or older with PTCLs, a group generally not transplant eligible, treated with systemic therapy with a focus on those treated with curative intent CHOP(like) chemotherapy. Methods The BC Cancer Lymphoid Cancer Database was reviewed and pts > 65 years with PTCL, not otherwise specified (PTCL-NOS), angioimmunoblastic T-cell lymphoma (AITL) as well as other T-Follicular Helper PTCL (collectively referred to as TFH T-cell lymphoma [TFHTCL]) diagnosed between 2000-2021 and who received front-line chemotherapy were included. Diagnoses were based on the World Health Organization (WHO) classifications of 2001, 2008, and 2017, depending on the era of diagnosis. Time to progression (TTP) was measured from the date of pathologic diagnosis to the date of relapse/progression, death due to treatment toxicity or lymphoma. Results 152 pts were initially identified, of which 5 were excluded: stage IA/IAE (n=3); CNS involvement only (n=2). Of the remaining 147 pts, 67 (46%) had PTCL-NOS and 80 (54%) had TFHTCL. The median age was 74 y (range 65-90) and the majority of pts had high risk features: International Prognostic Index (IPI) score of > 3 (n=113, 76%), stage III/IV disease (n=136, 93%) and PS of > 2 (n=85, 58%). Most pts (n=127, 86%) received multi-agent chemotherapy with curative intent. All pts received CHOP/CHOP-like chemotherapy (including five pts treated with CHP-brentuximab vedotin)Over half of these patients (n=66, 52%) received attenuated doses of chemotherapy starting from cycle 1, typically 50-75% dose intensity. Only two patients received consolidative autologous stem cell transplant. The remaining 20 patients received chemotherapy with palliative treatment intent, the majority (n=18, 90%) receiving cyclophosphamide alone or with the CVP (cyclophosphamide, vincristine, and prednisone) regimen. The median follow-up of all pts using the reverse Kaplan-Meier method was 9.2 y (range 0.9 to 12.5). The estimated 5-y TTP and overall survival (OS) for all patients were 21%, and 26%, respectively. Outcomes were similar in PTCL-NOS and TFHTCL (5-y TTP 17% vs 25%; p = 0.26). Curative intent chemotherapy was used more frequently in the 65-74 y vs > 75 y age group (70% vs 36%, p = 0.004). As expected, outcomes were superior in those treated with curative intent (Table 1): Median TTP of 11.3 months (m) vs 3.0 m; median OS of 24 m vs 4.5 m. Improvements in TTP and OS extended to those > 75 y (p < 0.001 for both). Considering the curative intent cohort, 91% of the relapse/progression events occurred within the first 3 y, and there was no significant difference in outcomes (5-y TTP/OS) with increasing age: 65-75 (19%/25%), >75 (34%/35%) (p = 0.08/0.6). Further, the outcomes of pts who received attenuated doses of CHOP-like chemotherapy were not inferior compared to full dose chemotherapy (5-y TTP/OS 32%/37% vs. 17%/21% p= 0.2/0.3). 5-y TTP/OS by the IPI ranged from 30%/52% for IPI of 1-2 to 12%/14% for IPI 4-5. The prognostic index for T-cell lymphoma (PIT) was more effective at identifying a lower risk group: 5-y TTP/ OS (PIT 1 40%/57%; PIT 2 21%/28%; PIT 3 21%/20% PIT 4 9%/10%, p = 0.002/0.001). Both models were prognostic in PTCL-NOS and TFHTCL. (Table 1) Conclusion With mature follow-up, ~ 30% of all older pts treated with curative intent CHOP-like chemotherapy remain progression-free and are alive at 5 y. Although results remain suboptimal, robust older patients can still be considered for curative intent CHOP chemotherapy with tailored doses to mitigate toxicity. Those with low risk IPI/PIT scores have a more favourable outcome with this approach, with a 5-y OS of > 50%, suggesting a benefit of subsequent therapies. In contrast, higher risk disease have poor outcomes and novel therapeutic approaches should be considered. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Novel Insights into Epigenetic Control of Autophagy in Cancer

The autophagy mechanism recycles the damaged and long-standing macromolecular substrates and thus maintains cellular homeostatic and proteostatic conditions. Autophagy can be an unavoidable target in cancer therapy because its deregulation leads to cancer formation and progression. Cancer can be controlled by regulating autophagy at different genetic, epigenetic, and post-translational levels. Epigenetics refers to the heritable phenotypic changes that affect gene activity without changing the sequence. Modern biology employs epigenetic alterations as molecular tools to detect and treat a wide range of disorders, including cancer. However, modulating autophagy at the epigenetic level may inhibit cancer growth and progression. Epigenetics-targeting drugs involved in preclinical and clinical trials may trigger antitumor immunity. Here, we have reviewed some experimental evidence in which epigenetics have been used to control deregulated autophagy in cancerous diseases. Furthermore, we also reviewed some current clinical trials of epigenetic therapy against cancer. We hope that this information can be utilized in the near future to treat and overcome cancer.

CircRNA SRRM4 affects glucose metabolism by regulating PKM alternative splicing via SRSF3 deubiquitination in epilepsy.

Several reports suggest that epigenetic therapy may be a potential method for treating epilepsy, and circular RNAs (circRNAs) play important roles in mediating the epigenetic mechanisms associated with epilepsy; however, currently there are no effective treatment methods to prevent the progression of epileptogenesis. The circRNA serine/arginine repetitive matrix 4 (circSRRM4) was found to exert regulatory effects in temporal lobe epilepsy (TLE); however, the mechanisms involved are still unknown. To elucidate the molecular mechanism of circSRRM4, we investigated human epileptic brain tissue, epileptic rats, neuron and astrocyte cell lines using RT-qPCR, western blot, fluorescence in situ hybridisation, immunofluorescence staining, Nissl stain, micro-PET-CT, RNA-pulldown, liquid chromatography-mass spectrometry, and RBP immunoprecipitation techniques. Furthermore, we evaluated the pyruvate kinase M1/2 (PKM) expression patterns in the human and rat models of TLE. We detected the increased circSRRM4 expression in the hypometabolic lesions of patients with TLE and discovered that circSrrm4 has specific spatiotemporal characteristics in rats with kainic acid-induced epilepsy. The decreased PKM1 expression and increased PKM2 expression were similar to the Warburg effect in tumours. Notably, circSrrm4 silencing reduced the incidence and frequency of epilepsy, improved local hypometabolism, and prevented neuronal loss and astrocyte activation. PKM2 promotes lactic acid production in the astrocytes by inducing glycolysis, thereby contributing to the energy source for epileptic seizures. Notably, circSRRM4 combines with and inhibits serine and arginine rich splicing factor 3 (SRSF3) from joining the ubiquitin-proteasome pathway, improving the SRSF3-regulated alternative splicing of PKM, and consequently stimulating glycolysis in cells.