The Role of BCL-2 and PD-1/PD-L1 Pathway in Pathogenesis of Myelodysplastic Syndromes.

Myelodysplastic syndromes (MDSs) belong to a group of clonal bone marrow malignancies. In light of the emergence of new molecules, a significant contribution to the understanding of the pathogenesis of the disease is the study of the B-cell CLL/lymphoma 2 (BCL-2) and the programmed cell death receptor 1 (PD-1) protein and its ligands. BCL-2-family proteins are involved in the regulation of the intrinsic apoptosis pathway. Disruptions in their interactions promote the progression and resistance of MDSs. They have become an important target for specific drugs. Bone marrow cytoarchitecture may prove to be a predictor of response to its use. The challenge is the observed resistance to venetoclax, for which the MCL-1 protein may be largely responsible. Molecules with the potential to break the associated resistance include S63845, S64315, chidamide and arsenic trioxide (ATO). Despite promising in vitro studies, the role of PD-1/PD-L1 pathway inhibitors has not yet been established. Knockdown of the PD-L1 gene in preclinical studies was associated with increased levels of BCL-2 and MCL-1 in lymphocytes T, which could increase their survival and promote tumor apoptosis. A trial (NCT03969446) is currently underway to combine inhibitors from both groups.

Polymorphisms in the Genes Coding for TLRs, NLRs and RLRs Are Associated with Clinical Parameters of Patients with Acute Myeloid Leukemia.

Toll-like receptors (TLRs), NOD-like receptors (NLRs), and RIG-I-like receptors (RLRs) are major elements of the innate immune system that recognize pathogen-associated molecular patterns. Single-nucleotide polymorphisms (SNPs) in the TLR, NLR, and RLR genes may lead to an imbalance in the production of pro- and anti-inflammatory cytokines, changes in susceptibility to infections, the development of diseases, and carcinogenesis. Acute myeloid leukemia (AML) is a bone marrow malignancy characterized by uncontrolled proliferation of transformed myeloid precursors. We retrospectively analyzed 90 AML patients. We investigated the effect of fifteen SNPs located in the genes coding for RLR1 (rs9695310, rs10738889, rs10813831), NOD1 (rs2075820, rs6958571), NOD2 (rs2066845, rs2066847, rs2066844), TLR3 (rs5743305, rs3775296, 3775291), TLR4 (rs4986791, rs4986790), and TLR9 (rs187084, rs5743836). We observed that TLR4 rs4986791, TLR9 rs5743836, and NOD2 rs2066847 were associated with CRP levels, while RLR-1 rs10738889 was associated with LDH level. Furthermore, we found TLR3 rs5743305 AA to be more common in patients with infections. We also found TLR9 rs187084 C to be associated with more favorable risk, and RLR-1 rs9695310 GG with higher age at diagnosis. In conclusion, the current study showed that SNPs in the genes encoding TLRs, NLRs, and RLRs may be potential biomarkers in patients with AML.

Toll-Like Receptors (TLRs), NOD-Like Receptors (NLRs), and RIG-I-Like Receptors (RLRs) in Innate Immunity. TLRs, NLRs, and RLRs Ligands as Immunotherapeutic Agents for Hematopoietic Diseases.

The innate immune system plays a pivotal role in the first line of host defense against infections and is equipped with patterns recognition receptors (PRRs) that recognize pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs). Several classes of PRRS, including Toll-like receptors (TLRs), NOD-like receptors (NLRs), and RIG-I-like receptors (RLRs) recognize distinct microbial components and directly activate immune cells. TLRs are transmembrane receptors, while NLRs and RLRs are intracellular molecules. Exposure of immune cells to the ligands of these receptors activates intracellular signaling cascades that rapidly induce the expression of a variety of overlapping and unique genes involved in the inflammatory and immune responses. The innate immune system also influences pathways involved in cancer immunosurveillance. Natural and synthetic agonists of TLRs, NLRs, or RLRs can trigger cell death in malignant cells, recruit immune cells, such as DCs, CD8+ T cells, and NK cells, into the tumor microenvironment, and are being explored as promising adjuvants in cancer immunotherapies. In this review, we provide a concise overview of TLRs, NLRs, and RLRs: their structure, functions, signaling pathways, and regulation. We also describe various ligands for these receptors and their possible application in treatment of hematopoietic diseases.

Infection and expression of Toll-like receptors in lymphoid malignancy patients after autologous stem cell transplantation.

INTRODUCTION: High-dose chemotherapy with autologous stem cell transplantation (ASCT) is one of the main strategies for the treatment of haematological neoplasms. Infections are the most common cause of morbidity and mortality from the ASCT procedure. However, it is challenging to predict when these complications are likely to arise. Toll-like receptors (TLRs) are present on various immune cells and play a broad role in immune surveillance. The aim of the study was to investigate the association between the expression of TLR genes and the occurrence of infections in patients treated with ASCT. MATERIAL AND METHODS: TLR expression was analysed in 60 patients who underwent ASCT. The median age was 54 years. Blood samples were taken before high-dose chemotherapy and at the time of haematopoietic recovery after ASCT. RESULTS: The expression of Toll-like receptor 4 (TLR4) was significantly higher in patients before ASCT than after transplantation. The expression of Toll-like receptor 9 (TLR9) was significantly higher in patients after ASCT than before transplantation. The expression of TLR9 and TLR4 at the start of the procedure was significantly lower in patients who went on to develop a bacterial infection after ASCT. Moreover, we also observed a significant positive correlation between the expression of TLR9 and neutrophil recovery time after ASCT. CONCLUSIONS: Our findings suggest that TLRs could be useful biomarkers to predict and monitor infections in patients treated with ASCT.

Higher efficacy of intermediate dose cytarabine + G-CSF compared to cyclophosphamide + G-CSF in hematopoietic stem cell mobilization in patients with multiple myeloma.

BACKGROUND: There are several regimens used in hematopoietic stem cell (HSC) mobilization in multiple myeloma (MM). Cyclophosphamide (Cy) is one of the most commonly used agents, although it does not always result in collecting adequate number of CD34+ cells. Recently, cytarabine (Ara-C) has been proposed as potentially efficient and safe option. AIMS: Since the data regarding Ara-C in HSC mobilization is limited, the aim of our study was to compare retrospectively the efficiency and toxicity of G-CSF combined with either Ara-C or Cy in MM patients. MATERIALS & METHODS: Of a total of 89 patients, 43 received low or intermediate doses of Cy, and 46 were treated with 800 mg/m2 /day of Ara-C administered for two days. RESULTS: The mean peak of CD34+ cells/ul in peripheral blood was 132 (range, 84-202) in Ara-C and 51 (range, 29-69) in Cy cohort (p < 0.001). The median number of collected CD34+ cells (×106/kg) was 10.3 (range, 4.2-17.9) vs 4.5 (range, 2.7-8.9), respectively (p < 0.001). Mobilization failure was observed in one patient in Ara-C cohort (2%) and in 8 patients treated with Cy (19%) (p = 0.013). In the Ara-C group 98% of patients obtained more than 4×106 CD34+ cells/kg required for tandem transplantation. Moreover, we observed a trend toward increased paraprotein levels measured at transplant compared to before HSC mobilization in Ara-C cohort and significantly higher transfusion rates in that group. CONCLUSION: Our findings confirm higher HSC mobilization efficacy of Ara-C compared to Cy in MM patients. However, lower transfusions rate and better disease control of Cy may justify its use in some cases.

The comparison of effectiveness and safety between different biosimilars of G-CSF in the mobilization of peripheral blood stem cells (PBSCs) for autologous transplantation (autologous peripheral blood stem cell transplantation, auto-PBSCT).

BACKGROUND: Autologous peripheral blood marrow stem cell transplantation (auto-PBSCT) preceded by high-dose chemotherapy is a well-known method of treatment for patients with hematological cancers. Performing the procedure entails obtaining from the patient their own stem cells from peripheral blood using G-CSF. Currently, various filgrastim biosimilars are widely used. AIM OF THE STUDY: The purpose of this study is to compare the efficacy and safety of three different biosimilars of filgrastim in PBSC mobilization in patients with hematological malignancies. MATERIALS AND METHODS: This is a retrospective analysis of 282 patients (118 women and 164 men) who underwent stem cells mobilization for auto-PBSCT in the Department of Hematology in Wroclaw in 2012-2014. Three filgrastim biosimilars were used: Tevagrastim (95), Nivestim (92), and Zarzio (95). Ninety patients (32%) were diagnosed with multiple myeloma, 55 (19%) with Hodgkin's lymphoma, 90 (32%) with NHLs, 20 (7%) with acute myeloid leukemia, and 27 (10%) with another hematological cancer. RESULTS: The mean number of CD34+ cells collected during the first leukapheresis was 5.95 × 106 /kg for Tevagrastim, 7.08 × 106 /kg for Nivestim, and 6.8 × 106 /kg for Zarzio (P > .05). The necessary number of leukapheresis for patients receiving Zarzio, Nivestim, and Tevagrastim was 1.32, 1.37, and 1.66, respectively (P > .05). The percentage of effective mobilizations was 88.2% for Zarzio, 86.2% for Nivestim, and 84.9% for Tevagrastim. The side effects included bone pain and headache. CONCLUSION: All tested biosimilars demonstrated similar effectiveness and safety profiles in patients with hematological tumors undergoing PBSC mobilization; therefore, they can be used interchangeably.

Primary Locations of Malignant Melanoma Lesions Depending on Patients' Gender and Age

Introduction: Location of malignant melanoma lesions depends on environmental, genetic, sociological and demographical factors. Available sources do not provide enough information on such dependencies in various populations. There is no data concerning the role of socio-demographic factors for the population of the Central and Eastern Europe. Aim: The aim of this work was to evaluate the anatomical location of the primary malignant melanoma lesion in correlation to patients' gender and age. Material and methods: A retrospective analysis of medical documentation of 363 patients has been performed. The patients had been diagnosed with malignant melanoma and were undergoing treatment in the years 2010-2014 in two Polish oncologic hospitals. The subject group consisted of 199 (55%) females and 164 (45%) males. The age varied between 19 - 90 years, with the median of 62 years. Results: In women, the melanoma lesions seem to appear more often in their lower extremities, while in case of men such lesions seem to be more often on their torsos. In both cases, the difference was statistically significant (p<0.01 When the specific locations are considered in women the lesions were more often located on their shins (p<0.01), whereas for men the lesions were located on their backs (p<0.01). It has been observed that there is dependency between lesion localization and age of patients. The lesions located on heads and necks were most common in older patients, and the lesions located in lower extremities were most common in younger ones. Conclusion: Differences in location of malignant melanoma lesions may be due to either genetic or environmental reasons. It is often emphasized in literature that correlation between the socio-demographic factors and the process of oncogenesis requires intensive research. In our work, we have tried to fill this gap for the population of Central and Eastern Europe to determine the exact epidemiology of this kind of cancer. This knowledge may be then used for developing cancer prevention methods specific to gender and age.