TET Enzymes in the Immune System: From DNA Demethylation to Immunotherapy, Inflammation, and Cancer.

Ten-eleven translocation (TET) proteins are iron-dependent and α-ketoglutarate-dependent dioxygenases that sequentially oxidize the methyl group of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC) and 5-carboxylcytosine (5caC). All three epigenetic modifications are intermediates in DNA demethylation. TET proteins are recruited by transcription factors and by RNA polymerase II to modify 5mC at enhancers and gene bodies, thereby regulating gene expression during development, cell lineage specification, and cell activation. It is not yet clear, however, how the established biochemical activities of TET enzymes in oxidizing 5mC and mediating DNA demethylation relate to the known association of TET deficiency with inflammation, clonal hematopoiesis, and cancer. There are hints that the ability of TET deficiency to promote cell proliferation in a signal-dependent manner may be harnessed for cancer immunotherapy. In this review, we draw upon recent findings in cells of the immune system to illustrate established as well as emerging ideas of how TET proteins influence cellular function.

Function of serine/arginine-rich splicing factors in hematopoiesis and hematopoietic malignancies.

The serine/arginine-rich splicing factors (SRSFs) play an important role in regulating the alternative splicing of precursor RNA (pre-RNA). During this procedure, introns are removed from the pre-RNA, while the exons are accurately joined together to produce mature mRNA. In addition, SRSFs also involved in DNA replication and transcription, mRNA stability and nuclear export, and protein translation. It is reported that SRSFs participate in hematopoiesis, development, and other important biological process. They are also associated with the development of several diseases, particularly cancers. While the basic physiological functions and the important roles of SRSFs in solid cancer have been extensively reviewed, a comprehensive summary of their significant functions in normal hematopoiesis and hematopoietic malignancies is currently absent. Hence, this review presents a summary of their roles in normal hematopoiesis and hematopoietic malignancies.

The role of exhausted natural killer cells in the immunopathogenesis and treatment of leukemia.

The immune responses to cancer cells involve both innate and acquired immune cells. In the meantime, the most attention has been drawn to the adaptive immune cells, especially T cells, while, it is now well known that the innate immune cells, especially natural killer (NK) cells, play a vital role in defending against malignancies. While the immune cells are trying to eliminate malignant cells, cancer cells try to prevent the function of these cells and suppress immune responses. The suppression of NK cells in various cancers can lead to the induction of an exhausted phenotype in NK cells, which will impair their function. Recent studies have shown that the occurrence of this phenotype in various types of leukemic malignancies can affect the prognosis of the disease, and targeting these cells may be considered a new immunotherapy method in the treatment of leukemia. Therefore, a detailed study of exhausted NK cells in leukemic diseases can help both to understand the mechanisms of leukemia progression and to design new treatment methods by creating a deeper understanding of these cells. Here, we will comprehensively review the immunobiology of exhausted NK cells and their role in various leukemic malignancies. Video Abstract.

The prognostic and therapeutic potential of HO-1 in leukemia and MDS.

BACKGROUND: Heme oxygenase-1 (HO-1), a heme-degrading enzyme, is proven to have anti-apoptotic effects in several malignancies. In addition, HO-1 is reported to cause chemoresistance and increase cell survival. Growing evidence indicates that HO-1 contributes to the course of hematological malignancies as well. Here, the expression pattern, prognostic value, and the effect of HO-1 targeting in HMs are discussed. MAIN BODY: According to the recent literature, it was discovered that HO-1 is overexpressed in myelodysplastic syndromes (MDS), chronic myeloid leukemia (CML), acute myeloblastic leukemia (AML), and acute lymphoblastic leukemia (ALL) cells and is associated with high-risk disease. Furthermore, in addition to HO-1 expression by leukemic and MDS cells, CML, AML, and ALL leukemic stem cells express this protein as well, making it a potential target for eliminating minimal residual disease (MRD). Moreover, it was concluded that HO-1 induces tumor progression and prevents apoptosis through various pathways. CONCLUSION: HO-1 has great potential in determining the prognosis of leukemia and MDS patients. HO-1 induces resistance to several chemotherapeutic agents as well as tyrosine kinase inhibitors and following its inhibition, chemo-sensitivity increases. Moreover, the exact role of HO-1 in Chronic Lymphocytic Leukemia (CLL) is yet unknown. While findings illustrate that MDS and other leukemic patients could benefit from HO-1 targeting. Future studies can help broaden our knowledge regarding the role of HO-1 in MDS and leukemia. Video abstract.

Lympho-hematopoietic malignancies risk after exposure to low dose ionizing radiation during cardiac catheterization in childhood.

Pediatric patients with congenital heart disease (CHD) often undergo low dose ionizing radiation (LDIR) from cardiac catheterization (CC) for the diagnosis and/or treatment of their disease. Although radiation doses from a single CC are usually low, less is known about the long-term radiation associated cancer risks. We aimed to assess the risk of lympho-hematopoietic malignancies in pediatric CHD patients diagnosed or treated with CC. A French cohort of 17,104 children free of cancer who had undergone a first CC from 01/01/2000 to 31/12/2013, before the age of 16 was set up. The follow-up started at the date of the first recorded CC until the exit date, i.e., the date of death, the date of first cancer diagnosis, the date of the 18th birthday, or the 31/12/2015, whichever occurred first. Poisson regression was used to estimate the LDIR associated cancer risk. The median follow-up was 5.9 years, with 110,335 person-years. There were 22,227 CC procedures, yielding an individual active bone marrow (ABM) mean cumulative dose of 3.0 milligray (mGy). Thirty-eight incident lympho-hematopoietic malignancies were observed. When adjusting for attained age, gender and predisposing factors to cancer status, no increased risk was observed for lympho-hematopoietic malignancies RR/mGy = 1.00 (95% CI: 0.88; 1.10). In summary, the risk of lympho-hematopoietic malignancies and lymphoma was not associated to LDIR in pediatric patients with CHD who undergo CC. Further epidemiological studies with greater statistical power are needed to improve the assessment of the dose-risk relationship.

On radar and radio exposure and cancer in the military setting.

INTRODUCTION: In 2018, we reported a case series of 47 patients diagnosed with cancer following several years of exposure to high-intensity whole-body radiofrequency radiation (RFR) using the parameter of percentage frequency (PF). Consistent high and statistically significant PFs of hematolymphoid (HL) cancers were found in this group and in four previous reports on RFR-exposed groups in Belgium, Poland and Israel together with increased all-cancers rates. In this paper we report a new series of 46 young cancer patients who were exposed during military service to such radiation. MATERIALS AND METHODS: The new group of patients comprises Israeli soldiers previously exposed to occupational RFR. The patients were self-selected to enroll in the research in cooperation with an NGO assisting patients with administrative counseling and legal and social services. The new group of patients was studied with respect to distribution (proportion) of cancer types using the method of PF. When possible, cancer risk ratios (RR) were estimated too. The results are compared to those of other occupational groups in three countries. RESULTS: Median age at diagnosis was 23 years; duration of exposure was between 1 and 3 years and the latencies were short, median 4.6 years. The PF of HL cancers was 41.3%, 95% CI (27%-57%), versus 22.7% expected in non-exposed subjects matched for age and gender profiles, p = 0.003; 19 out of the 46 patients had HL cancers. The PF of Hodgkin lymphoma cancers was 21.7%, 95%CI (11%-36%), versus 11.6% expected, p = 0.033. For a subgroup of 6 patients, the number of soldiers in the units was known, and we were able estimate approximately the overall cancer risk ratio (RR) after 8 years as being 8.0 with 95% CI (2.9, 17), p < 0.002, with only 0.75 cases expected from the Cancer Registry data. In this subgroup, there were 3 HL cancer cases and 3 non-HL cases. Sarcoma PF was higher than expected, 7 out of the 46 patients were diagnosed with sarcoma, PF = 15.2%, 95%CI (6.3%-28.9%), p = 0.04 versus the expected PF of 7%. CONCLUSION: The HL PF was high and consistent with previous reports. Epidemiological studies on excess risk for HL and other cancers, brain tumors in cellphone users, and experimental studies on RFR and carcinogenicity strongly point to a cause-effect relationship. It is mandatory to reduce the RFR exposure of all personnel to that of the typical community levels, including the peak level of radar pulses. Radiation protection, safety instructions, cancer risk warnings and quantitative data on individual exposure together with regular medical monitoring must be instituted for all personnel exposed to such risks. The findings from our study add to the growing body of evidence underscoring the gross inadequacy of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) thermal standards. Based on our findings and on the previous accumulated research, we endorse the recommendations to reclassify RFR exposure as a human carcinogen, International Agency for Research on Cancer (IARC) group 1.

Stagnation in quality of next-generation sequencing assays for the diagnosis of hereditary hematopoietic malignancies.

Hereditary hematopoietic malignancies (HHMs) are inherited syndromes that confer the risk of blood cancer development. With the rapid acceleration of next-generation sequencing (NGS) into commercial biotechnology markets, HHMs are increasingly recognized by genetic counselors and clinicians. In 2020, it was demonstrated that most diagnostic test offerings for HHMs were insufficient for accurate diagnosis, failing to sequence the full spectrum of genetic events known to cause HHMs. We hypothesized the number of genes on commercially available HHM assay increased from 2020 to 2022, consistent with a more comprehensive sequencing approach. Here, we analyzed assays from eight commercial laboratories to determine the HHM-related genes sequenced by these assays. We compared these assays with panels from 2020 to determine trends in sequencing quality. Most HHM diagnostic assays did not change and remain insensitive for the detection of all HHM-related variants. Most (75%) HHM assays do not sequence CHEK2, the gene most frequently mutated in HHMs, and 25% of HHM assays does not sequence DDX41, the second most frequent HHM driver. The quality of HHM diagnostic assays stagnated despite the discovery of novel HHM-related genes and prior work demonstrating heterogeneity in the quality of HHM testing. Most commercially available HHM tests remain insufficient.

A practical guide to interpreting germline variants that drive hematopoietic malignancies, bone marrow failure, and chronic cytopenias.

PURPOSE: The American College of Medical Genetics and Genomics and the Association for Molecular Pathology guidelines for germline variant interpretation are implemented as a broad framework by standardizing variant interpretation. These rules were designed to be specified, but this process has not been performed for most of the 200 genes associated with inherited hematopoietic malignancies, bone marrow failure, and cytopenias. Because guidelines on how to perform these gene specifications are lacking, variant interpretation is less reliable and reproducible. METHODS: We have used a variety of methods such as calculations of minor allele frequencies, quasi-case-control studies to establish thresholds, proband counting, and plotting of receiver operating characteristic curves to compare different in silico prediction tools to design recommendations for variant interpretation. RESULTS: We herein provide practical recommendations for the creation of thresholds for minor allele frequencies, in silico predictions, counting of probands, identification of functional domains with minimal benign variation, use of constraint Z-scores and functional evidence, prediction of nonsense-mediated decay, and assessment of phenotype specificity. CONCLUSION: These guidelines can be used by anyone interpreting variants associated with inherited hematopoietic malignancies, bone marrow failure, and cytopenias to develop criteria for reliable, accurate, and reproducible germline variant interpretation.

Two novel piperidones induce apoptosis and antiproliferative effects on human prostate and lymphoma cancer cell lines.

Cancer remains the second most common cause of death in the US. Due to a recurrent problem with anticancer drug resistance, there is a current need for anticancer drugs with distinct modes of action for combination drug therapy We have tested two novel piperidone compounds, named 2608 (1-dichloroacetyl - 3,5-bis(3,4-difluorobenzylidene)-4-piperidone) and 2610 (1-dichloroacetyl-3,5-bis(3,4-dichlorobenzylidene)-4-piperidone), for their potential cytotoxicity on numerous human cancer cell lines. We found that both compounds were cytotoxic for breast, pancreatic, leukemia, lymphoma, colon, and fibroblast cell lines, with a cytotoxic concentration 50% (CC50) in the low micromolar to nanomolar concentration range. Further assays focused primarily on an acute lymphoblastic lymphoma and colon cancer cell lines since they were the most sensitive and resistant to the experimental piperidones. The cell death mechanism was evaluated through assays commonly used to detect the induction of apoptosis. These assays revealed that both 2608 and 2610 induced reactive oxygen species (ROS) accumulation, mitochondrial depolarization, and activated caspase-3/7. Our findings suggest that the piperidones induced cell death via the intrinsic apoptotic pathway. Additional assays revealed that both piperidones cause cell cycle alteration in lymphoma and colon cell lines. Both piperidones elicited DNA fragmentation, as evidenced by an increment in the sub-G0/G1 subpopulation in both cell lines. Similar to other related compounds, both piperidones were found to act as proteasome inhibitors by increasing the levels of poly-ubiquitinated proteins in both lymphoma and colon cell lines. Hence, the two piperidones exhibited attractive cytotoxic properties and suitable mechanisms of action, which makes them good candidates as anticancer drugs.

Assessment of technical heterogeneity among diagnostic tests to detect germline risk variants for hematopoietic malignancies.

PURPOSE: To determine the degree of testing consistency among commercially available diagnostic assays for hereditary hematopoietic malignancies (HHMs). METHODS: Next-generation sequencing assays designed for the diagnosis of HHMs were studied to determine which genes were sequenced, their ability to detect variant types relevant for HHMs, and clinical-grade characteristics such as price, turnaround time, and tissue types accepted. RESULTS: Commercial assays varied in price (USD 250-4702), number of genes sequenced (12-73), and average turnaround time (14-42 days). A number of nongermline tissue types were accepted despite the tests being designed for germline diagnostic purposes. Multiple genes with well-characterized roles in HHM pathogenesis were omitted from more than one-third of panels intended for the evaluation of HHMs. Only 4 of 82 genes were consistently covered across all HHM diagnostic panels. The assays were highly variable in their sensitivity for structural alterations relevant to HHMs, such as copy-number variants. CONCLUSION: A high degree of diagnostic heterogeneity exists among commercially available HHM diagnostic assays. Many of these assays are incapable of detecting the full spectrum of HHM-associated variants, leaving patients vulnerable to the consequences of underdiagnosis, missed opportunities for screening, and the potential for donor-derived malignancies.

Interaction of increasing ICU survival and admittance policies in patients with hematologic neoplasms: A single center experience with 304 patients.

OBJECTIVE: We evaluated the development of ICU survival of patients with hematopoietic malignancies and discussed changes in admittance policies. METHOD: We compared 166 patients treated between 2009 and 2012 with 138 patients treated between 2013 and 2016. Patient characteristics and outcome were analyzed. RESULTS: ICU survival was 45.2% in the first group and 66.7% in the second (P < 0.0005). Infection (P = 0.033), invasive ventilation (IMV) (P = 0.014) and SOFA score at day 3 (SOFA-48h) (P = 0.007) independently indicated worse ICU survival in the first group, IMV (P = 0.013) and SOFA-48h (P = 0.019) in the second group. The second group showed lower frequencies of infection (P = 0.003), IMV (P < 0.0005), need for vasopressors (P < 0.0005) and RRT (P = 0.021) at ICU admittance than the first. Further, the accumulation of hyperkaliemia, acidosis, low bicarbonate, high lactate and hypotension showed worse ICU survival in both groups and was lower in second group. CONCLUSION: ICU survival increased distinctly between 2009 and 2016. At ICU admittance, parameters showing severity of illness were less frequent in the second group. Our findings indicate general treatment improvements especially of infections and changes of admittance policies toward early ICU admittance during time.

Selective bio-labeling and induced apoptosis of hematopoietic cancer cells using dual-functional polyethylenimine-caged platinum nanoclusters.

In the past decades, platinum (Pt) is employed to clinical treatment of various cancers. However, for Pt-based drugs, especially Pt in +2 state [Pt (II)], such as cisplatin, number of drawbacks impede their anticancer efficiency including poor pharmacology, fast blood clearance, systemic toxicities causing from poor specificity and excretion of drug through kidneys. Herein, we developed dual-functional ultrafine polyethylenimine caged platinum nanoclusters (PEI-caged Pt NCs), which were utilized in biological imaging of the suspension cells system as fluorescent markers, and selective inhibition of hematopoietic malignancies as anticancer chemotherapeutics simultaneously. These zerovalent Pt NCs are capable to selectively enter into blood cancer cells (K562, BV173 cell lines) when compared to the peripheral blood mononucleated cells (PBMCs) from healthy donors, in addition, it can specifically induce pro-apoptotic protein expression (p53, PUMA, cleaved caspase) in hematopoietic cancer cells and promote cell apoptosis. Avoiding the adding of other fluorescent bio-markers, these Pt NCs showed great potential in diagnosis and treatment of hematopoietic system disease, such as acute myeloid leukemia, lymphoma, myeloma, etc.

JAK-STAT signaling in cancer: From cytokines to non-coding genome.

In the past decades, studies of the Janus kinases (JAKs) and signal transducers and activators of transcription (STATs) signaling have uncovered highly conserved programs linking cytokine signaling to the regulation of essential cellular mechanisms such as proliferation, invasion, survival, inflammation and immunity. Inhibitors of the JAK/STAT pathway are used for treatment of autoimmune diseases, such as rheumatoid arthritis or psoriasis. Aberrant JAK/STAT signaling has been identified to contribute to cancer progression and metastatic development. Targeting of JAK/STAT pathway is currently one of the most promising therapeutic strategies in prostate cancer (PCa), hematopoietic malignancies and sarcomas. Notably, newly identified regulators of JAK/STAT signaling, the non-coding RNAs transcripts and their role as important targets and potential clinical biomarkers are highlighted in this review. In addition to the established role of the JAK/STAT signaling pathway in traditional cytokine signaling the non-coding RNAs add yet another layer of hidden regulation and function. Understanding the crosstalk of non-coding RNA with JAK/STAT signaling in cancer is of critical importance and may result in better patient stratification not only in terms of prognosis but also in the context of therapy.

Differential sensitivity to JAK inhibitory drugs by isogenic human erythroblasts and hematopoietic progenitors generated from patient-specific induced pluripotent stem cells.

Disease-specific induced pluripotent stem cells (iPSCs) provide an unprecedented opportunity to establish novel disease models and accelerate drug development using distinct tissue target cells generated from isogenic iPSC lines with and without disease-causing mutations. To realize the potential of iPSCs in modeling acquired diseases which are usually heterogeneous, we have generated multiple iPSC lines including two lines that are JAK2-wild-type and four lines homozygous for JAK2-V617F somatic mutation from a single polycythemia vera (PV) patient blood. In vitro differentiation of the same patient-derived iPSC lines have demonstrated the differential contributions of their parental hematopoietic clones to the abnormal erythropoiesis including the formation of endogenous erythroid colonies. This iPSC approach thus may provide unique and valuable insights into the genetic events responsible for disease development. To examine the potential of iPSCs in drug testing, we generated isogenic hematopoietic progenitors and erythroblasts from the same iPSC lines derived from PV patients and normal donors. Their response to three clinical JAK inhibitors, INCB018424 (Ruxolitinib), TG101348 (SAR302503), and the more recent CYT387 was evaluated. All three drugs similarly inhibited erythropoiesis from normal and PV iPSC lines containing the wild-type JAK2 genotype, as well as those containing a homozygous or heterozygous JAK2-V617F activating mutation that showed increased erythropoiesis without a JAK inhibitor. However, the JAK inhibitors had less inhibitory effect on the self-renewal of CD34+ hematopoietic progenitors. The iPSC-mediated disease modeling thus underlies the ineffectiveness of the current JAK inhibitors and provides a modeling system to develop better targeted therapies for the JAK2 mutated hematopoiesis.

Genetically determined telomere length as a risk factor for hematological malignancies: evidence from Mendelian randomization analysis.

BACKGROUND: Over the past years, the exact correlation between telomere length and hematological malignancies was still not fully understood. METHODS: We performed a two-sample Mendelian randomization study to investigate the causal relationship between telomere length and hematological malignancies. We selected genetic instruments associated with telomere length. The genetic associations for lymphoid and hematopoietic malignant neoplasms were obtained from the most recent publicly accessible FinnGen study R9 data. Inverse variant weighted (IVW) analysis was adopted as the primary method, and we also performed the weighted-median method and the MR-Egger, and MRPRESSO methods as sensitive analysis. RESULTS: Significant associations have been observed between telomere length and primary lymphoid (IVW: OR = 1.52, P = 2.11 × 10-6), Hodgkin lymphoma (IVW: OR = 1.64, P = 0.014), non-Hodgkin lymphoma (IVW: OR = 1.70, P = 0.002), B-cell lymphoma (IVW: OR = 1.57, P = 0.015), non-follicular lymphoma (IVW: OR = 1.58, P = 1.7 × 10-3), mantle cell lymphoma (IVW: OR = 3.13, P = 0.003), lymphoid leukemia (IVW: OR = 2.56, P = 5.92E-09), acute lymphocytic leukemia (IVW: OR = 2.65, P = 0.021) and chronic lymphocytic leukemia (IVW: OR = 2.80, P = 8.21 × 10-6), along with multiple myeloma (IVW: OR = 1.85, P = 0.016). CONCLUSION: This MR study found a significant association between telomere length and a wide range of hematopoietic malignancies. But no substantial impact of lymphoma and hematopoietic malignancies on telomere length has been detected.

Role of Wiskott Aldrich syndrome protein in haematological malignancies: genetics, molecular mechanisms and therapeutic strategies.

As patients continue to suffer from lymphoproliferative and myeloproliferative diseases known as haematopoietic malignancies can affect the bone marrow, blood, lymph nodes, and lymphatic and non-lymphatic organs. Despite advances in the current treatment, there is still a significant challenge for physicians to improve the therapy of HMs. WASp is an important regulator of actin polymerization and the involvement of WASp in transcription is thought to be linked to the DNA damage response and repair. In some studies, severe immunodeficiency and lymphoid malignancy are caused by WASp mutations or the absence of WASp and these mutations in WAS can alter the function and/or expression of the intracellular protein. Loss-of-function and Gain-of-function mutations in WASp have an impact on cancer malignancies' incidence and onset. Recent studies suggest that depending on the clinical or experimental situation, WASPs and WAVEs can operate as a suppressor or enhancers for cancer malignancy. These dual functions of WASPs and WAVEs in cancer likely arose from their multifaceted role in cells that could be targeted for anticancer drug development. The significant role and their association of WASp in Chronic myeloid leukaemia, Juvenile myelomonocytic leukaemia and T-cell lymphoma is discussed. In this review, we described the structure and function of WASp and its family mechanism, analysing major regulatory effectors and summarising the clinical relevance and drugs that specifically target WASp in disease treatment in various hematopoietic malignancies by different approaches.

Emerging Role of [18F]FLT PET/CT in Lymphoid Malignancies: A Review of Clinical Results.

Fluorine-18 fluorodeoxyglucose ([18F]FDG) is nowadays the leading positron emission tomography (PET) tracer for routine clinical work-ups in hematological malignancies; however, it is limited by false positive findings. Notably, false positives can occur in inflammatory and infective cases or in necrotic tumors that are infiltrated by macrophages and other inflammatory cells. In this context, 3'-deoxy-3'-[18F]fluorothymidine ([18F]FLT) has been shown to be a promising imaging biomarker of hematological malignant cell proliferation. In this review, a total of 15 papers were reviewed to collect literature data regarding the clinical application of [18F]FLT PET/CT in hematological malignancies. This imaging modality seems to be a suitable tool for noninvasive assessment of tumor grading, also showing a correlation with Ki-67 immunostaining. Moreover, [18F]FLT PET/CT demonstrated high sensitivity in detecting aggressive lymphoma lesions, especially when applying a standardized uptake value (SUV) cutoff of 3. At baseline, the potential of [18F]FLT imaging as a predictive tool is demonstrated by the low tracer uptake in patients with a complete response. However, its use is limited in evaluating bone diseases due to its high physiological uptake in bone marrow. Interim [18F]FLT PET/CT (iFLT) has the potential to identify high-risk patients with greater precision than [18F]FDG PET/CT, optimizing risk-adapted therapy strategies. Moreover, [18F]FLT uptake showed a greater ability to differentiate tumor from inflammation compared to [18F]FDG, allowing the reduction of false-positive findings and making the first one a more selective tracer. Finally, FLT emerges as a superior independent predictor of PFS and OS compared to FDG and ensures a reliable early response assessment with greater accuracy and predictive value.

The E3 ligase DTX2 inhibits RUNX1 function by binding its C terminus and prevents the growth of RUNX1-dependent leukemia cells.

Transcription factor RUNX1 plays important roles in hematopoiesis and leukemogenesis. RUNX1 function is tightly controlled through posttranslational modifications, including ubiquitination and acetylation. However, its regulation via ubiquitination, especially proteasome-independent ubiquitination, is poorly understood. We previously identified DTX2 as a RUNX1-interacting E3 ligase using a cell-free AlphaScreen assay. In this study, we examined whether DTX2 is involved in the regulation of RUNX1 using in vitro and ex vivo analyses. DTX2 bound to RUNX1 and other RUNX family members RUNX2 and RUNX3 through their C-terminal region. DTX2-induced RUNX1 ubiquitination did not result in RUNX1 protein degradation. Instead, we found that the acetylation of RUNX1, which is known to enhance the transcriptional activity of RUNX1, was inhibited in the presence of DTX2. Concomitantly, DTX2 reduced the RUNX1-induced activation of an MCSFR luciferase reporter. We also found that DTX2 induced RUNX1 cytoplasmic mislocalization. Moreover, DTX2 overexpression showed a substantial growth-inhibitory effect in RUNX1-dependent leukemia cell lines. Thus, our findings indicate a novel aspect of the ubiquitination and acetylation of RUNX1 that is modulated by DTX2 in a proteosome-independent manner.

Prioritization of patients for germline testing based on tumor profiling of hematopoietic malignancies.

Germline predisposition to hematopoietic malignancies is more common than previously appreciated, with several clinical guidelines advocating for cancer risk testing in an expanding pool of patients. As molecular profiling of tumor cells becomes a standard practice for prognostication and defining options for targeted therapies, recognition that germline variants are present in all cells and can be identified by such testing becomes paramount. Although not to be substituted for proper germline cancer risk testing, tumor-based profiling can help prioritize DNA variants likely to be of germline origin, especially when they are present on sequential samples and persist into remission. Performing germline genetic testing as early during patient work-up as possible allows time to plan allogeneic stem cell transplantation using appropriate donors and optimize post-transplant prophylaxis. Health care providers need to be attentive to the differences between molecular profiling of tumor cells and germline genetic testing regarding ideal sample types, platform designs, capabilities, and limitations, to allow testing data to be interpreted as comprehensively as possible. The myriad of mutation types and growing number of genes involved in germline predisposition to hematopoietic malignancies makes reliance on detection of deleterious alleles using tumor-based testing alone very difficult and makes understanding how to ensure adequate testing of appropriate patients paramount.

Detection of Nonhematologic Neoplasms in Bone Marrow by Flow Cytometry: A Report of Two Cases.

Multiparameter flow cytometry (MFC) is a well-established method for the diagnosis, prognosis, and follow-up of a vast majority of hematological malignancies; however, it can have a major impact on the rapid diagnosis of nonhematopoietic tumor micrometastases in minimally invasive samples such as bone marrow aspirates (BMAs), body fluids, and tissue samples (lymph nodes, fine needle aspirates). Here, we present two cases of bone marrow micrometastases of neuroendocrine origin (one small cell lung carcinoma [SCLC] and one large cell neuroendocrine carcinoma [LCNEC] of the lungs) readily recognized by routine MFC investigation of BMA and review the existing literature on the role of MFC in the diagnosis of solid tumors of neuroendocrine origin. The clinical application of flow cytometry for the diagnosis of solid tumors is limited despite the accumulating evidence of the value of the method. It can be of great value in situations where the patient's clinical status forbids invasive procedures, and a rapid diagnosis is desirable. Flow cytometry is a valuable tool for the detection of both hematological and nonhematologic neoplasms. Future large-scale patient series will probably confirm its role in the screening, diagnosis, and classification of more tumor types.