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Background/Aim: Primary mediastinal large Bcell lymphoma (PMLBCL) is an aggressive B-cell non- Hodgkin lymphoma (NHL), whose prognosis has greatly improved since the incorporation of the anti-CD20 monoclonal antibody rituximab into current therapeutic regimens. Evidence, however, on the optimal time interval between consecutive chemoimmunotherapy (CIT) cycles is still scarce. This study aimed to evaluate the efficacy outcomes of the more commonly administered 3-weekly regimens to the biweekly ones in a PMLBCL patients' population, who were mostly treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone every 21 days (R-CHOP-21) or R-CHOP-14. Patients and Methods: We retrospectively studied our cohort of consecutively treated PMLBCL patients, focusing on their treatment density, in order to determine possible differences in treatment outcomes. Results: CIT, in the form of both RCHOP- 21 as well as R-CHOP-14 (or similar regimens), is highly active in PMLBCL, with low rates of early treatment failure. In our cohort of patients, R-CHOP-14 did not result in a meaningful improvement of freedom from progression (FFP) or overall survival (OS). Conclusion: Both R-CHOP- 14 and R-CHOP-21 are probably equally effective in PMLBCL, yet further, prospective, randomized studies are warranted to clarify whether dose-dense regimens can be associated with better disease control and long-term results. © 2022 International Institute of Anticancer Research. All rights reserved.

Red blood cell transfusions (RBCT) remain the cornerstone of supportive care in lower-risk myelodysplastic syndrome (LRMDS) [1]. Transfusion dependency in LRMDS patients is associated with inferior outcomes, mainly attributed to severe bone marrow failure [2]. However, iron toxicity, due to frequent RBCT or ineffective erythropoiesis, may be an additional negative prognostic factor [3,4,5,6]. Recently, much progress has been made in unraveling the iron metabolism. The peptide hormone hepcidin is the key regulator by inhibiting iron uptake through degradation of ferroportin, a cellular iron exporter [7]. Erythroferrone and GDF15, produced by erythroblasts, inhibit hepcidin production, which leads to increased uptake and cellular release of iron for the purpose of erythropoiesis [8]. The pathophysiology of iron metabolism in MDS is still not completely understood. Exceedingly high reactive oxygen species (ROS) levels are associated with iron toxicity, disease development, and progression in MDS patients [9,10,11,12]. Malondialdehyde (MDA), resulting from lipid peroxidation of polyunsaturated fatty acids, is a biomarker of oxidative stress [10, 12]. Currently, little is known about the prognostic impact of ROS in MDS patients. The aim of this study is twofold: (1) describe iron and oxidative stress parameters over time in LRMDS patients and (2) to assess their effect on overall and progression-free survival. The EUMDS registry prospectively collects observational data on newly diagnosed LRMDS patients from 148 centers in 16 countries in Europe and Israel as of January 2008. All patients provided informed consent. Clinical data were collected at baseline and at each six-monthly follow-up visit. Serum samples were collected prospectively at each visit from 256 patients included in six participating countries. Conventional iron parameters were measured with routine assays. We additionally analyzed hepcidin, growth differentiation factor 15 (GDF15), soluble transferrin receptor (sTfR), non-transferrin bound iron (NTBI), labile plasma iron (LPI), and MDA. Subjects were prospectively followed until death, loss to follow-up, or withdrawal of consent. All iron parameters were measured centrally at the department of Laboratory Medicine of the Radboudumc, Nijmegen, The Netherlands. Serum samples were collected just prior to transfusion in transfusion-dependent patients and stored at −80 °C. Details on the assays and reference ranges of hepcidin, GDF15, sTfR, NTBI, LPI, and MDA are provided in the supplement. The Spearman rank test was used to evaluate correlations between iron parameters. We stratified the results by transfusion dependency per visit and the presence of ring sideroblasts. When evaluating temporal changes in iron parameters, with linear quantile mixed models, we excluded patients from the timepoint they received iron chelation therapy. Overall survival (OS) was defined as the time from MDS diagnosis to death or, in case of progression-free survival, to date of progression or death; patients still alive at the end of follow-up were censored. Time-dependent Kaplan–Meier curves and cox proportional hazards models were used. In total, 256 consecutive patients, were included in this study. Over five six-monthly visits, 1040 samples were collected. Table 1 describes the patient characteristics. Most patients without ring sideroblasts were transfusion-independent at diagnosis (nonRS-TI; 55.9%), 18.8% with ring sideroblasts were transfusion-independent (RS-TI), 18.4% without ring sideroblasts were transfusion-dependent (nonRS-TD), and 7% with ring sideroblasts were transfusion-dependent patients (RS-TD). The median follow-up time was 6.6 years (95% CI 5.9–7.0). LPI was positively correlated with transferrin saturation (TSAT) (r = 0.15, p < 0.001, Fig. S1). LPI values increased exponentially at TSAT values above 80%. This effect was most pronounced in the transfusion-dependent groups, but also observed in the RS-TI group. MDA was weakly correlated with NTBI (r = 0.09, p = 0.069) and negatively correlated with hemoglobin level (r = −0.1, p = 0.033). GDF15 and hepcidin were negatively correlated in the RS-TI and nonRS-TD group and significantly negatively correlated in the RS-TD group (r = −0.34, p = 0.007, Fig. S2). Serum ferritin levels were elevated in all subgroups with a mean value of 858 µg/L at visit 5. The highest serum ferritin levels were observed in the RS-TD group (mean value at visit 5: 2092 µg/L, Table S1). Serum ferritin increased significantly per visit in the RS-TD group (beta 454.46 µg/L; 95% CI 334.65–574.27), but not in the other groups (Table S2). All subgroups, except for the nonRS-TI, had elevated TSAT levels. TSAT levels were most markedly increased in the RS-TD group with a mean TSAT of 88% at visit 5 (Table S1). In both transfusion-dependent groups the median increase per visit was significant (Table S2). LPI was elevated in the RS-TD group exclusively with a mean value of 0.59 µmol/L at visit 5 (Table S1). NTBI was elevated in all subgroups, with the highest values in the RS-TD group (Table S1). The increase in median NTBI level was significant in both transfusion-dependent groups (Table S2). Hepcidin levels were markedly elevated in the nonRS-TD group. Interestingly, hepcidin levels were lower in the RS-TD group, probably reflecting ineffective erythropoiesis, likewise supported by lower hepcidin/ferritin ratios in RS groups (Table S1). Median hepcidin levels increased over time in the transfusion-dependent subgroups only (Table S2). GDF15 levels, analyzed in the light of its potential role in hepcidin suppression, were increased in all subgroups (Table S1). The RS subgroups had higher GDF15 levels compared to the nonRS groups, reflecting increased erythropoiesis. Mean sTfR levels were within the reference range in all subgroups except for the RS-TI group, which showed elevated levels, reflecting...

5-azacytidine (5-AZA) is considered the standard of care for patients with high-risk myelodysplastic syndromes (MDS) and patients with acute myeloid leukemia (AML) not candidate for intensive chemotherapy. However, even after an initial favorable response, almost all patients relapse, with the exact mechanisms underlying primary or secondary 5-AZA resistance remaining largely unknown. Several reports have previously demonstrated the significance of hypoxia in the regulation of both physiological and malignant hematopoiesis. In MDS, high hypoxia inducible factor 1α (Hif-1α) expression has been correlated with poor overall survival and disease progression, while its involvement in the disease's pathogenesis was recently reported. We herein investigated the possible association of the Hif-1α signaling pathway with response to 5-AZA therapy in MDS/AML patients. Our data demonstrated that 5-AZA-responders present with higher Hif-1α mRNA and protein expression compared to 5-AZA-non-responders/stable disease patients, before the initiation of therapy, while, interestingly, no significant differences in Hif-1α mRNA expression at the 6-month follow-up were observed. Moreover, we found that 5-AZA-responders exhibited elevated mRNA levels of the Hif-1α downstream targets lactate dehydrogenase a (LDHa) and BCL2 interacting protein 3 like (BNIP3L), a further indication of an overactivated Hif-1a signaling pathway in these patients. Kaplan–Meier survival analysis revealed a significant correlation between high Hif-1α mRNA expression and better survival rates, while logistic regression analysis showed that Hif-1α mRNA expression is an independent predictor of response to 5-AZA therapy. From the clinical point of view, apart from proposing Hif-1α mRNA expression as a significant predictive factor for response to 5-AZA, our data offer new perspectives on MDS combinational therapies, suggesting a potential synergistic activity of 5-AZA and Hif-1α inducers, such as propyl hydroxylases inhibitors (PHDi). © 2020 John Wiley & Sons Ltd.

End-of-treatment (EoT) PET/CT is used as a guide to omit radiotherapy (RT) patients with primary mediastinal large B-cell lymphoma (PMBCL). We present the mature and extended results of a retrospective study evaluating the prognostic significance of EoT-PET/CT after adequate response to R-CHOP. Among 231 consecutive PMLBCL patients, 182 underwent EoT-PET/CT and were evaluated according to the Deauville 5-point scale (D5PS) criteria. Freedom from progression (FFP) was measured from the time of PET/CT examination. Among 182 patients, 72 (40%) had D5PS score 1 (D5PSS-1), 33 (18%) had 2, 28 (15%) had 3, 29 (16%) had 4, and 20 (11%) had 5. The 5-year FFP was 97, 94, 92, 82, and 44% for D5PSS-1, D5PSS-2, D5PSS-3, D5PSS-4, and D5PSS-5, respectively. Among 105 patients with unequivocally negative PET/CT (D5PSS-1/D5PSS-2), 49 (47%) received RT (median dose 3420 cGy) and 56 (53%) did not with relapses in 0/49 vs. 4/56 patients (2 mediastinum and 2 isolated CNS relapses).The 5-year FFP for those who received RT or not was 100% versus 96%, when isolated CNS relapses were censored (p = 0.159). Among D5PSS-3 patients (27/28 irradiated-median dose 3600 cGy), the 5-year FFP was 92%. The 5-year FFP for D5PSS-4 and D5PSS-5 was 82 and 44%; 44/49 patients received RT (median dose 4000 and 4400 cGy for D5PSS-4 and D5PSS-5). Our study supports the omission of RT in a sizeable fraction of PET/CT-negative patients and definitely discourages salvage chemotherapy and ASCT in patients with PMLBCL who conventionally respond to R-CHOP, solely based on PET/CT positivity in the absence of documented progressive or multifocal disease. The persistence of positive PET/CT with D5PSS < 5 after consolidative RT should not trigger the initiation of further salvage chemotherapy in the absence of conventionally defined PD. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.

CD+1 T cells orchestrate immune responses and are actively engaged in shaping tumor immunity. Signal transducer and activator of transcription (STAT) signaling controls the epigenetic tuning of CD+1 T-cell differentiation and polarization, and perturbed STAT signaling networks in CD+1 T cells subvert antitumor immunity in malignancies. Azacitidine (AZA), the mainstay therapy for high-risk myelodysplastic syndromes (HR-MDS), affects CD+1 T-cell polarization and function, but whether this contributes to AZA efficacy is currently unknown. By using functional proteomic, transcriptomic, andmutational analyses in 73 HR-MDS patients undergoing AZA therapy, we demonstrate that responding patients exhibited a coordinated CD+1 T-cell immune response and downregulated the inflammatory cytokine signaling pathways in CD+1 T cells after AZA, in contrast to nonresponders who upregulated the same pathways. We further observed an AZA-mediated downregulation of intereukin-6 (IL-6)- induced STAT3 phosphorylation in CD+1FOXP32 conventional T cells (Tcons) that correlated independently with better response and survival, whereas it was also not associated with the mutation number and profile of the patients. The AZA-induced downregulation of IL-6/STAT3 axis in Tcons restored the STAT signaling architecture in CD+1 T-cell subsets, whereas STAT signaling networks remained disorganized in patients who upregulated IL-6/STAT3 activity in Tcons. Given the pivotal role of CD+1 T cells in adaptive immunity, our findings suggest that the downregulation of the IL-6/STAT3 pathway in Tcons potentially constitutes a previously unrecognized immune-mediatedmechanism of action of AZA and sets the scene for developing rational strategies of AZA combinations with IL-6/STAT3 axis inhibitors. © 2021 by The American Society of Hematology.

Background: 5-azacytidine (5-AZA) improves survival of patients with higher-risk myelodysplastic syndromes (MDSs) and oligoblastic acute myeloid leukemia (AML); however, predictive factors for response and outcome have not been consistently studied. Methods: This study of the Hellenic MDS Study Group included 687 consecutive patients with higher-risk MDS and oligoblastic AML treated with 5-AZA. Results: The International Prognostic Scoring System (IPSS) revised version (IPSS-R), Eastern Cooperative Oncology Group Performance Status (ECOG PS) (0 or 1 versus ⩾2) and baseline serum ferritin (SF) levels > 520 ng/ml were shown to independently predict response to 5-AZA. In the survival analysis, the IPSS and IPSS-R risk classification systems along with the ECOG PS and SF levels > 520 ng/ml proved to be independent prognosticators for overall survival (OS), as well as for leukemia-free survival (LFS). Next, we built new multivariate models for OS and LFS, incorporating only ECOG PS and SF levels besides IPSS or IPSS-R risk classification systems. Thereby, the new modified IPSS and IPSS-R risk classification systems (H-PSS, H-PSS-R) could each discriminate a low, an intermediate and a high-risk patient group regarding OS and LFS. The H-PSS and H-PSS-R proved to be better predictors of OS than their previous counterparts as well as the French prognostic score, while the most powerful OS predictor was the new, H-PSS-R system. Conclusions: ECOG PS and SF levels > 520 ng/ml independently predict response to 5-AZA, OS and LFS. Their incorporation in the IPSS and IPSS-R scores enhances these scores’ predictive power in 5-AZA-treated higher-risk MDS and oligoblastic AML patients. © The Author(s), 2020.

Background: Hypomethylating agents have altered the prognosis of myelodysplastic syndrome (MDS) so that long-term survival is now a feasible treatment goal. Patients and Methods: We analyzed data from patients with MDS treated with 5-azacytidine recorded in the Hellenic 5-azacytidine registry. We divided patients, on the basis of their survival after 5-azacytidine initiation (OST), in groups of long-term survivors (Q3 and P90 group with OST above the third quartile and the 90th percentile of the whole group, respectively) and short-term survivors comprising the remaining patients, and compared the characteristics between the groups. The study included 626 patients, 157 in the Q3 group and 63 in the P90 group. Results: Categorization per the International Prognostic Scoring System (IPSS), revised IPSS (IPSS-R), and World Health Organization–based prognostic scoring system (WPSS) was found to predict long-term survival, while multivariate analysis revealed that response to 5-azacytidine was the strongest predictor of long-term survival. Nevertheless, patients with hematologic improvement (HI) and stable disease (SD) were equally distributed in the groups of short- and long-term survival. Conclusion: SD should not be considered a poor treatment response and should not be grouped with failure, while HI offers similar prognosis to SD and thus should not be grouped with complete and partial remission. Patients with SD should continue treatment with 5-azacytidine. The prognosis of myelodysplastic syndrome (MDS) has changed since the introduction of hypomethylating agents that offer the potential for long-term survival. We studied the characteristics of long-term survival in a cohort of 626 patients with MDS treated with 5-azacytidine; response was found to be the single most important predictive factor of long-term survival, while stable disease (SD) and hematologic improvement were equally distributed in the groups with long- and short-term survival. Achieving SD has prognostic significance, and SD should not be grouped with treatment failure. © 2019 Elsevier Inc.

Background: Regular transfusions are the gold standard therapy for β-thalassemia and are often complicated by secondary-iron overload and alloimmunization. We assessed the frequency of regulatory T cells (Tregs) and the levels of cytokines implicated in Th-responses in 49 patients 33 TDT and 16 NTDT in order to investigate the contribution of transfusion and its complications on immune responses. Materials and methods: Tregs were characterized with flow cytometry. Soluble IL-4, IL-6, IL-10, IL-17A, and TGF-β1 were assessed by ELISA. Clinical data including alloimmunization, age of onset of transfusion splenectomy hepatitis B and C infection, iron overload assessment with MRI T2* (liver and heart) were recorded from the patients' files. Results: Tregs levels, IL-6, IL-10, TGFβ and serum ferritin were higher in the TDT compared to the NTDT group (all p < 0.05). There was no difference of Tregs and circulating cytokines in patients in correlation with the extend of iron overload (assessed by T2*liver), the type of chelator or the development of alloantibodies. Discussion: Tregs levels are higher in TDT patients compared to NTDT, a difference which could be ascribed to transfusion. Tregs levels and the cytokines analyzed may play little role in alloimmunization and are not impacted by the extend of iron overload. © 2020

Higher-risk Myelodysplastic syndromes (MDS) patients undergoing treatment with 5-azacytidine (AZA) are typically elderly with several comorbidities. However, the effect of comorbidities on the effectiveness and safety of AZA in real-world settings remains unclear. We analyzed data from 536 AZA-treated patients with higher-risk MDS, Myelodysplastic/Myeloproliferative neoplasms and low blast count Acute Myeloid Leukemia enrolled to the Hellenic National Registry of Myelodysplastic and Hypoplastic Syndromes. Multivariate analysis adjusted also for the International Prognostic Scoring System (IPSS), its revised version (IPSS-R) and the French Prognostic Scoring System (FPSS), demonstrated independent associations of overall and leukemia-free survival with estimated glomerular filtration rate (eGFR) 2 mg/dL, can be utilized as a more precise indicator of renal comorbidity during AZA therapy. Incorporation of eGFR in the prognostic assessment of AZA-treated MDS patients may prove useful not only in routine practice, but also for the appropriate patient stratification in clinical trials with AZA combinations. © 2020 John Wiley & Sons Ltd

Background and Objectives: Somatic mutations in the calreticulin gene (CALR) are detected in approximately 70% of patients with essential thrombocythemia (ET) and primary or secondary myelofibrosis (MF), lacking the JAK2 and MPL mutations. To determine the prevalence of CALR frameshift mutations in a population of MPN patients of Greek origin, we developed a rapid low-budget PCR-based assay and screened samples from 5 tertiary Haematology units. This is a first of its kind report of the Greek patient population that also disclosed novel CALR mutants. Methods: MPN patient samples were collected from different clinical units and screened for JAK2 and MPL mutations after informed consent was obtained. Negative samples were analyzed for the presence of CALR mutations. To this end, we developed a modified post Real Time PCR High-Resolution Melting Curve analysis (HRM-A) protocol. Samples were subsequently confirmed by Sanger sequencing. Results: Using this protocol we screened 173 MPN, JAK2 and MPL mutation negative, patients of Greek origin, of whom 117 (67.63%) displayed a CALR exon nine mutation. More specifically, mutations were detected in 90 out of 130 (69.23%) essential thrombocythaemia cases (ET), in 18 out of 33 (54.55%) primary myelofibrosis patients (pMF) and in 9 out of 10 (90%) cases of myelofibrosis secondary to ET (post-ET sMF). False positive results were not detected. The limit of detection (LoD) of our protocol was 2%. Furthermore, our study revealed six rare novel mutations which are to be added in the COSMIC database. Conclusions: Overall, our method could rapidly and cost-effectively detect the mutation status in a representative cohort of Greek patients; the mutation make-up in our group was not different from what has been published for other national groups. © Universita Cattolica del Sacro Cuore. All rights reserved.

Hypomethylating agents are widely used in chronic myelomonocytic leukemia (CMML). We analyzed the characteristics of 88 patients with CMML homogeneously treated with 5-azacytidine (Hellenic 5-Azacytidine Registry). The overall response rate was 48.9% and the median overall survival (OS) 29.7 months. Out of the seven most widely used prognostic scoring systems for CMML, the Dusseldorf score (DUSS) showed the best prognostic capability (HR, 2.27; p

In patients with myelodysplastic syndrome (MDS), the prognostic significance of chromosome 17 abnormalities has not yet been fully elucidated, except for isochromosome 17q that has been characterized as an intermediate risk abnormality in the Revised International Prognostic Scoring System (IPSS-R). To further characterize the prognostic significance of chromosome 17 abnormalities we analyzed the hematologic and prognostic characteristics of 548 adult patients with MDS treated with 5-azacytidine through the Hellenic 5-azacytidine registry and found 32 patients with a chromosome 17 abnormality (6 with i[17q], 15 with -17, 3 with add[17p] and the rest with other rarer abnormalities, mostly translocations). The presence of a chromosome 17 abnormality was correlated with poor prognostic features (high IPSS, IPSS-R, and WPSS scores) and a low overall survival rate (15.7 vs 36.4 months for patients without chromosome 17 abnormalities, Kaplan–Meier, Log Rank P

Poly (ADP-ribose) polymerase 1 (PARP1) is a nuclear enzyme that participates in the DNA repair of malignant cells, with various consequences on their survival. We have recently shown that PARP1 mRNA levels in the bone marrow of patients with myelodysplastic syndrome (MDS) are correlated to prognosis. To evaluate PARP1 as a biomarker of response to 5-azacytidine in patients with MDS, we measured PARP1 mRNA levels by a quantitative real-time PCR in diagnostic bone marrow samples of 77 patients with MDS treated with 5-azacytidine. Patients with higher PARP1 mRNA levels had a better response to 5-azacytidine per the IWG criteria (p = 0.006) and a longer median survival after 5-azacytidine initiation (p = 0.033). Multivariate analysis revealed that PARP1 mRNA level was the only factor affecting response to treatment and survival after treatment with 5-azacytidine. A next-generation sequencing for 40 genes of interest in MDS and quantification of the methylation levels of the PARP1 promoter were also carried out in a subset of samples (16 and 18 samples respectively). It is the first time that a single, easily measurable biomarker shows a clear correlation with response to treatment and survival in a patient population consisting of previously untreated patients with MDS homogeneously treated with 5-azacytidine. The fact that PARP1 is also a treatment target in several malignancies underscores the importance of our finding for the potential use of PARP1 inhibitors in MDS. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.

In this study, we investigated the incidence and prognostic impact of monosomal karyotype (MK) in 405 higher-risk Myelodysplastic Syndromes (MDS) patients treated with 5-AZA. The MK was present in 66 out of 405 (16.3%) patients, most of whom had complex karyotype (CK). MK was strongly associated with CK and the cytogenetic risk defined according to IPSS-R, as well as with high-risk disease, according to IPSS (P =.029), IPSS-R (P

The demethylating factor 5-azacytidine (5-AZA) improves survival in intermediate-2 and high-risk myelodysplastic syndrome (MDS) patients [according to the International Prognostic Score System (IPSS)] responding to treatment. However, the outcome of patients achieving stable disease (SD) is unclear. This retrospective study of the Hellenic MDS Study Group included 353 intermediate-2 or high IPSS risk patients treated with 5-AZA. Forty-four out of 86 (51.6%) patients achieving SD and continuing treatment with 5-AZA showed a lower risk of transformation of MDS to acute myeloid leukemia (AML) and increased overall survival (OS), compared to SD patients who discontinued the treatment (estimated median AML-free survival = 38 months, 95% CI = 10.7-65.3 vs 15 months, 95% CI = 10.4-19.6, P

Poly (ADP-ribose) polymerase 1 (PARP-1) has a central role in the repair of DNA breaks and is a promising treatment target in malignancy. We measured PARP1 mRNA levels by a SYBR-green-based PCR in the bone marrow of 74 patients with myelodysplastic syndrome (MDS) and correlated them to their demographic, hematologic and prognostic characteristics. The median PARP1 mRNA levels were correlated to the type of MDS (2008/2016 WHO classification, P = 0.005) and to the IPSS score (P = 0.002). A correlation was also found with the IPSS-R score (P = 0.011) and the cytogenetic risk (P = 0.008). In all cases, higher PARP1 levels were correlated with a higher risk category. Moreover, we found a significant survival disadvantage for patients with high PARP1 levels (median survival of 37.4 months versus 'not reached' for low PARP1 levels, P = 0.0001, and a 5-year survival rate of 29.8 versus 88.9%, respectively). PARP1 mRNA levels were found to be the stronger predictor of survival in multivariate analysis. These correlations have never been reported in the past and may render PARP1 a prognostic factor to be incorporated in the current prognostic systems for MDS, also laying the basis for clinical trials evaluating PARP1 inhibitors in higher-risk MDS. © 2017 the American College of Gastroenterology.

Purpose: Azacitidine is the mainstay of high-risk myelodysplastic syndromes (MDS) therapy, but molecular predictors of response and the mechanisms of resistance to azacitidine remain largely unidentified. Deregulation of signaling via Stat3 and Stat5 in acute myeloid leukemia (AML) is associated with aggressive disease. Numerous genes involved in cell signaling are aberrantly methylated inMDS, yet the alterations and the effect of azacitidine treatment on Stat3/5 signaling in high-risk MDS have not been explored. Experimental Design: We assessed longitudinally constitutive and ligand-induced phospho-Stat3/5 signaling responses by multiparametric flow cytometry in 74 patients with MDS and low blast count AML undergoing azacitidine therapy. Pretreatment Stat3/5 signaling profiles in CD34+ cells were grouped by unsupervised clustering. The differentiation stage and the molecular properties of the CD34+ G-CSF-inducible Stat3/5 double-positive subpopulation were performed by flow cytometry and quantitative real-time PCR in isolated MDS progenitors. Results: The pretreatment Stat3/5 signaling profiles in CD34+ cells correlated strongly with response and cytogenetics and independently predicted event-free survival. We further identified a CD34+ G-CSF-inducible Stat3/5 double-positive subpopulation (DP subset) whose pretreatment levels were inversely associated with treatment response and cytogenetics. The kinetics of the DP subset followed the response to azacitidine and the disease course, whereas its molecular characteristics and cellular hierarchy were consistent with a leukemia propagating cell phenotype. Conclusions: Our findings provide a novel link among Stat3/5 signaling and MDS pathobiology and suggest that the Stat3/5 signaling biosignature may serve as both a response biomarker and treatment target. © 2015 AACR.

The protein tyrosine phosphatase SHP-1 dephosphorylates BCR-ABL1, thereby serving as a potential control mechanism of BCR-ABL1 kinase activity. Pathways regulating SHP-1 expression, which could be exploited in the therapeutics of TKI-resistant chronic myeloid leukemia (CML), remain unknown. Moreover, the questions of whether there is any kind of SHP-1 deregulation in CML, contributing to disease initiation or evolution, as well as the question of prognostic significance of SHP-1, have not been definitively answered. This study shows moderately lower SHP-1 mRNA expression in chronic phase CML patients in comparison to healthy individuals and no change in SHP-1 mRNA levels after successful TKI treatment. Mutational analysis of the aminoterminal and phosphatase domains of SHP-1 in patients did not reveal genetic lesions. This study also found no correlation of SHP-1 expression at diagnosis with response to treatment, although a trend for lower SHP-1 expression was noted in the very small non-responders group of the 3-month therapeutic milestone. © 2015 Taylor and Francis.

Myelodysplastic syndrome (MDS) patients with renal impairment (RI) were not assessed in the approval trials of 5-azacytidine, thus the optimal use of 5-azacytidine in such patients is currently undefined. We retrospectively analyzed 42 IPSS intermediate-2 and high-risk patients with moderate, mild or no RI undergoing 5-azacytidine therapy in a non-trial setting. We demonstrate that patients in all three groups achieved comparable responses and had similar overall and event-free survival. Likewise, both treatment toxicity and dose adjustments were not significantly influenced by renal function status. A transient but reversible decline in glomerular filtration rate was observed in patients either with or without RI, without affecting the therapeutic schedule. Our results provide the first evidence that 5-azacytidine is effective and well-tolerated in patients with mild and moderate RI and, if confirmed by prospective randomized studies, advocate that such patients can be managed in an analogous fashion to patients with normal renal function. © 2013 Elsevier Ltd.