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Tumor cells promote the suppression of host anti-tumor type 1 T cell responses by various mechanisms, including the upregulation of surface inhibitory molecules such as programmed death ligand (PD-L)-1, and the production of immunosuppressive cytokines such as interleukin-10 (IL-10). There are over 2000 trials investigating PD-L1 and/or its receptor programmed-death 1 (PD-1) blockade in cancer, leading to the approval of PD-1 or PD-L1 inhibitors in several types of solid cancers and in hematological malignancies. The available data suggest that the molecule PD-L1 on antigen-presenting cells suppresses type 1 T cell immune responses such as cytotoxicity, and that the cytokine IL-10, in addition to downregulating immune responses, increases the expression of inhibitory molecule PD-L1. We hypothesize that the manipulation of both the co-inhibitory network (with anti-PD-L1 blocking antibodies) and suppressor network (with anti-IL-10 blocking antibodies) is an attractive immunotherapeutic intervention for acute myeloid leukemia (AML) patients ineligible for standard treatment with chemotherapy and hematopoietic stem cell transplantation, and with less severe adverse reactions. The proposed combination of these two immunotherapies represents a new approach that can be readily translated into the clinic to improve the therapeutic efficacy of AML disease treatment.

It is a new and exciting time for acute lymphoblastic leukemia (ALL). While nearly 50 years ago, only one in nine children with ALL survived with chemotherapy, nowadays nearly 90% of children have a chance of long-term survival. Adults with ALL, as well as the special category of adolescents and young adult (AYA) patients, are catching up with the new developments seen in children, but still their prognosis is much worse. A plethora of factors are regarded as responsible for the differences in treatment response, such as age, ethnicity, disease biology, treatment regimens and toxicities, drug tolerance and resistance, minimal residual disease evaluation, hematopoietic stem cell transplantation timing and socio-economic factors. Taking these factors into account, bringing pediatric-like protocols to adult patient management and incorporating new agents into frontline treatment could be the key to improve the survival rates in adults and AYA.

Checkpoint inhibitors were a major breakthrough in the field of oncology. In September 2014, based on the KEYNOTE-001 study, the Food and Drug Administration (FDA) approved pembrolizumab, a programmed cell death protein 1 (PD-1) inhibitor, for advanced or unresectable melanoma. Up until now, seven PD-1/PD-ligand(L)-1 inhibitors are approved in various solid cancers and hundreds of clinical studies are currently ongoing. In hematology, PD-1 inhibitors nivolumab and pembrolizumab were approved for the treatment of relapsed/refractory (R/R) classic Hodgkin lymphoma, and later pembrolizumab was approved for R/R primary mediastinal large B-cell lymphoma. In acute myeloid leukemia (AML), the combination of hypomethylating agents and PD-1/PD-L1 inhibitors has shown promising results, worth of further investigation, while other combinations or single agent therapy have disappointing results. On the other hand, rather than in first line, these therapies could be useful in the consolidation or maintenance setting, for achieving minimal residual disease negativity. Furthermore, an interesting application could be the use of PD-1/PD-L1 inhibitors in the post allogeneic hematopoietic stem cell transplantation relapse. There are several reasons why checkpoint inhibitors are not very effective in treating AML, including the characteristics of the disease (systemic, rapidly progressive, and high tumor burden disease), low mutational burden, and dysregulation of the immune system. We here review the results of PD-1/PD-L1 inhibition in AML and discuss their potential future in the management of this disease.

TET2 is a dioxygenase dependent on Fe 2+ and α-ketoglutarate which oxidizes 5-methylcytosine (5meC) to 5-hydroxymethylcytosine (5hmeC). TET proteins successively oxidize 5mC to yield 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC). Among these oxidized methylcytosines, 5fC and 5caC are directly excised by thymine DNA glycosylase (TDG) and ultimately replaced with unmethylated cytosine. Mutations in TET2 have been shown to lead to a hypermethylated state of the genome and to be responsible for the initiation of the oncogenetic process, especially in myeloid and lymphoid malignancies. Nonetheless, this was also shown to be the case in other cancers. In AML, TET2 mutations have been observed to be mutually exclusive with IDH1 , IDH2 , and WT1 mutations, all of them showing a similar impact on the transcription profile of the affected cell. Because of this, it is possible that TET2/IDH1/2/WT1 mutated AML could be considered as having similar characteristics between each other. Nonetheless, other genes also interact with TET2 and influence its effect, thus making it possible that other signatures exist that would mimic the effect of TET2 mutations. Thus, in this review, we searched the literature for the genes that were observed to interact with TET2 and classified them in the following manner: transcription alteration, miRs, direct interaction, posttranslational changes, and substrate reduction. What we propose in the present review is the potential extension of the TET2/IDH1/2/WT1 entity with the addition of certain expression signatures that would be able to induce a similar phenotype with that induced by TET2 mutations. Nonetheless, we recommend that this approach be taken on a disease by disease basis.

Background and objectives: Mutational analysis has led to a better understanding of acute myeloid leukemia (AML) biology and to an improvement in clinical management. Some of the most important mutations that affect AML biology are represented by mutations in genes related to methylation, more specifically: TET2 , IDH1 , IDH2 and WT1 . Because it has been shown in numerous studies that mutations in these genes lead to similar expression profiles and phenotypes in AML, we decided to assess if mutations in any of those genes interact with other genes important for AML. Materials and Methods: We downloaded the clinical data, mutational profile and expression profile from the TCGA LAML dataset via cBioPortal. Data were analyzed using classical statistical methods and functional enrichment analysis software represented by STRING and GOrilla. Results: The first step we took was to assess the 196 AML cases that had a mutational profile available and observe the mutations that overlapped with TET2/IDH1/2/WT1 mutations. We observed that RUNX1 mutations significantly overlap with TET2/IDH1/2/WT1 mutations. Because of this, we decided to further investigate the role of RUNX1 mutations in modulating the level of RUNX1 mRNA and observed that RUNX1 mutant cases presented higher levels of RUNX1 mRNA. Because there were only 16 cases of RUNX1 mutant samples and that mutations in this gene determined a change in mRNA expression, we further observed the correlation between RUNX1 and other mRNAs in subgroups regarding the presence of hypermethylating mutations and NPM1 . Here, we observed that both TET2/IDH1/2/WT1 and NPM1 mutations increase the number of genes negatively correlated with RUNX1 and that these genes were significantly linked to myeloid activation. Conclusions: In the current study, we have shown that NPM1 and TET2/IDH1/2/WT1 mutations increase the number of negative correlations of RUNX1 with other transcripts involved in myeloid differentiation.

Background and Objectives: Hematological malignancies are usually systemic diseases of life-threatening impact, and frequently require prompt and energetic therapeutic intervention. Due to systemic involvement, the role of surgery is generally limited to diagnostic approaches, and it is very rarely employed as a therapeutic modality. Splenectomy represents an exception to this paradigm, being used both as a diagnostic and tumor debulking procedure, notably in splenic lymphomas. Materials and Methods: We investigated the role of splenectomy in a single center prospective study of splenectomy outcome in patients with splenic involvement in the course of lymphoproliferative disorders. In the present study, we included all patients treated in our department for lymphoid malignancies over a period of six years, who underwent splenectomy as a diagnostic or debulking procedure after referral and workup, or had been referred to our department after first being splenectomized and diagnosed with splenic lymphoma. Patient characteristics and treatment outcome were investigated. Results : We enrolled 54 patients, with 34 (63%) splenectomized patients: 12 splenectomies (22.2%) for diagnostic purposes and 22 (40.7%) for treatment. Special attention was given to the 28 (51.85%) patients diagnosed with splenic marginal zone lymphoma (SMZL), a subtype with a clear therapeutic indication for splenectomy. Average age of patients was 57.5 (±13.1) years with a higher prevalence of feminine gender (66.67%). Age above 60 years old ( p = 0.0295), ECOG (Eastern Cooperative Oncology Group) > 2 ( p = 0.0402) and B-signs ( p nonsignificant (NS)) were most frequently found in SMZL patients. Anemia, and notably autoimmune anemia, was more frequent in SMZL versus other small-cell lymphomas and also in splenectomized patients, as was leukocytosis and lymphocytosis. Treatment of patients with lymphoproliferative disorders consisted of chemotherapy and/or splenectomy. Most SMZL patients received chemotherapy as first line treatment (61.5%) and had only partial response (57.7%). Second treatment line was splenectomy in 80% of patients who required treatment, followed by a 60% rate of complete response (CR). Splenectomy offered a higher complete response rate (twice as high than in non-splenectomized, regardless of histology type, p = NS), followed by a survival advantage (Overall Survival (OS)~64 versus 59 months, p = NS). Particularly, SMZL patients had a 4.8 times higher rate of CR than other non-Hodgkin lymphoma (NHL) patients ( p = 0.04), a longer progression free survival (73 months vs. 31 months for other small-cell NHLs p = NS) and a 1.5fold lower death rate ( p = NS). The procedure was rather safe, with a 38.5% frequency of adverse reactions, mostly minor and manageable. Conclusions: Our data suggest that splenectomy is an effective and safe therapeutic option in patients with lymphoid malignancies and splenic involvement, particularly splenic marginal zone lymphoma.