Towards the Application of Atorvastatin to Intensify Proapoptotic Potential of Conventional Antileukemic Agents In Vitro

It has been previously revealed that statins used at high concentrations display antileukemic potential towards chronic lymphocytic leukemia (CLL) cells. However, their usage alone in clinical practice may be limited due to possible side effects of high doses of these drugs. On the other hand, combined treatment of leukemia with statins and the conventional chemotherapeutics is questionable because of unknown influence of the first on the standard treatment results. This study has revealed that in vitro atorvastatin increases the proapoptotic potential of cladribine and mafosfamide in CLL cells isolated from peripheral blood of patients. Moreover, a preincubation with the above statin sensitizes leukemic cells to CM-induced apoptosis even at small concentrations of the drug. The usage of atorvastatin together with or followed by the conventional chemotherapy should be considered as therapeutic option for the treatment for this leukemia. Interestingly, CM-resistant patients might have the biggest benefits from atorvastatin administration.Grant no. 1407 from the University of Łódź

The role of neuronal apoptosis inhibitory protein (NAIP) in acute myeloid leukemia patients

Acute myeloid leukemia (AML) is a heterogeneous, highly malignant neoplasm. Apoptosis is a complex process executed by caspases and suppressed by the inhibitor of apoptosis (IAP) family. Neuronal apoptosis inhibitory protein (NAIP), IAP’s member, may play an exceptional role in the mechanisms of tumors’ resistance to chemotherapy. The aims of the study were to assess the expression of NAIP in leukemic blasts of AML patients using flow cytometry and to evaluate its influence on disease outcome. NAIP expression was found in 106 out of 108 patients. A higher complete response rate was associated with a low expression of NAIP, age < 60 yo, and white blood cell count < 20 G/L ( = 0.009, = 0.033, and = 0.076, respectively) in univariate analyses and a low NAIP expression and age < 60 yo ( = 0.025 and = 0.013, respectively) in multivariate analyses. Longer overall survival (OS) in the univariate analysis was influenced by a low NAIP expression, age < 60 yo, and intensive chemotherapy ( = 0.033, < 0.001, and < 0.001, respectively). In the intensively treated group, better OS was observed in patients with age < 60 yo, AML, and a low NAIP expression ( = 0.03, = 0.024, and = 0.07, respectively). In multivariate analysis, longer OS was associated with age < 60 yo ( = 0.009) and AML ( = 0.007). In conclusion, we suggest that NAIP might play an adverse role in response to chemotherapy

POTENTIAL GENETIC AGENT BFL1 FOR TARGETED THERAPY IN CHRONIC LYMPHOCYTIC LEUKEMIA

Background: Many prognostic factors have been identified in chronic lymphocytic leukemia (CLL) but new ones are still desired. The biological characterization of CLL is now being translated into novel treatment strategies. One new prognostic factor, and therapeutic target, may be BFL1. It is both a serum and a molecular marker that contributes to the progression of CLL and its resistance to chemotherapy. The aim of this study was to evaluate the prognostic value of BFL1 and to assess its correlation with other known prognostic markers in CLL for the cladribine and cyclophosphamide regimen (CC). Methods: qPCR TaqMan® Low Density Array was used for gene expression measurements. Assessment of CD38, ZAP70 and BFL-1 proteins expression was done by means of flow cytometry. Serum TK activity was measured by immunoassay. Results: Protein BFL1 expression was found to be significantly higher in CLL patients than healthy volunteers (p=0.001). Moreover its level was significantly higher in patients with no response (NR) to CC therapy (p=0.009). The expression of BFL1 was considerably down regulated during CC treatment and BFL1 mRNA levels were inversely correlated with apoptotic response. In addition, protein BFL1 expression was found to be similar to thymidine kinase (TK) concentration regarding treatment response. As far as other markers are concerned, a positive correlation was identified between BFL1 and TK (r=0.52, p=0.01). Conclusions: Our findings suggest that BFL1 contributes to chemoresistance and may be a co-existing prognostic factor in CLL in the future

Cytotoxic Activity of Melatonin Alone and in Combination with Doxorubicin and/or Dexamethasone on Diffuse Large B-Cell Lymphoma Cells in In Vitro Conditions

Melatonin (MLT), a pineal gland hormone, not only regulates circadian and seasonal rhythms, but also plays an important role in many aspects of human physiology and pathophysiology. MLT is of great interest as a natural substance with anti-cancer activities. The aim of this study was to assess the cytotoxicity and apoptosis of MLT, used alone or in combination with one of the most active anti-cancer drugs, doxorubicin (DOX), and a well-known anti-inflammatory drug, dexamethasone (DEX), on a diffuse large B-cell lymphoma (DLBCL)-derived cell line. The cytotoxicity and cell cycle distribution were measured using propidium iodide staining, while apoptosis was assessed using the annexin-V binding method. Additionally, to elucidate the mechanisms of action, caspase-3, -8, and -9 and a decline in the mitochondrial potential were determined using flow cytometry. MLT inhibited cell viability as well as induced apoptosis and cell cycle arrest at the G0/G1 phase. The pro-apoptotic effect was exerted through both the mitochondrial and caspase-dependent pathways. Furthermore, we observed increased cytotoxic and pro-apoptotic activity as well as the modulation of the cell cycle after the combination of MLT with DOX, DEX, or a combination of DOX + DEX, compared with both drugs or MLT used alone. Our findings confirm that MLT is a promising in vitro anti-tumour agent that requires further evaluation when used with other drugs active against DLBCL

Cytotoxic activity of R-amphinase, an anti-tumor endoribonuclease, on diffuse large B-cell lymphoma cells in conditions

Onconase (ONC) and R-Amphinase (R-AM) are enzymes with anti-tumor activity, belonging to pancreatic ribonuclease A family, received from eggs collected from frog Rana pipiens. Both proteins can induce death of some types of neoplastic cells by inhibition of protein synthesis, cell growth and proliferation. The aim of this study was to assess the cytotoxicity of R-AM, used alone or in combination with one of the most active anti-leukemic drug, doxorubicin (DOX), on diffuse large B-cell lymphoma (DLBCL)-derived cell line, Toledo. We found high cytotoxic activity of R-AM against DLBCL cells as well as influence on expression of several apoptosis-regulating proteins. Moreover, we observed increase in proapoptotic activity after combination of R-AM and DOX, compared with both drugs used alone. These results may justify further studies on interactions of R-AM with other drugs active in DLBCL

Expression of Toll-Like Receptors 3, 7, and 9 in Peripheral Blood Mononuclear Cells from Patients with Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease of unknown aetiology. The results of experimental studies point to the involvement of innate immunity receptors—toll-like receptors (TLR)—in the pathogenesis of the disease. The aim of the study was to assess the expression of TLR3, 7, and 9 in the population of peripheral blood mononuclear cells (PBMC) and in B lymphocytes (CD19+), T lymphocytes (CD4+ and CD8+) using flow cytometry. The study group included 35 patients with SLE and 15 healthy controls. The patient group presented a significantly higher percentage of TLR3- and TLR9-positive cells among all PBMCs and their subpopulations (CD3+, CD4+, CD8+, and CD19+ lymphocytes) as well as TLR7 in CD19+ B-lymphocytes, compared to the control group. There was no correlation between the expression of all studied TLRs and the disease activity according to the SLAM scale, and the degree of organ damage according to the SLICC/ACR Damage Index. However, a correlation was observed between the percentage of various TLR-positive cells and some clinical (joint lesions) and laboratory (lymphopenia, hypogammaglobulinemia, anaemia, and higher ESR) features and menopause in women. The results of the study suggest that TLR3, 7, and 9 play a role in the pathogenesis of SLE and have an impact on organ involvement in SLE

Atypical Chronic Lymphocytic Leukemia—The Current Status

A diagnosis of typical chronic lymphocytic leukemia (CLL) requires the presence of ≥5000 clonal B-lymphocytes/μL, the coexistence of CD19, CD20, CD5, and CD23, the restriction of light chain immunoglobulin, and the lack of expression of antigens CD22 and CD79b. Atypical CLL (aCLL) can be distinguished from typical CLL morphologically and immunophenotypically. Morphologically atypical CLL cells have been defined mainly as large, atypical forms, prolymphocytes, or cleaved cells. However, current aCLL diagnostics rely more on immunophenotypic characteristics rather than atypical morphology. Immunophenotypically, atypical CLL differs from classic CLL in the lack of expression of one or fewer surface antigens, most commonly CD5 and CD23, and the patient does not meet the criteria for a diagnosis of any other B-cell lymphoid malignancy. Morphologically atypical CLL has more aggressive clinical behavior and worse prognosis than classic CLL. Patients with aCLL are more likely to display markers associated with poor prognosis, including trisomy 12, unmutated IGVH, and CD38 expression, compared with classic CLL. However, no standard or commonly accepted criteria exist for differentiating aCLL from classic CLL and the clinical significance of aCLL is still under debate. This review summarizes the current state of knowledge on the morphological, immunophenotypic, and genetic abnormalities of aCLL

Novel Clofarabine-Based Combinations with Polyphenols Epigenetically Reactivate Retinoic Acid Receptor Beta, Inhibit Cell Growth, and Induce Apoptosis of Breast Cancer Cells

An epigenetic component, especially aberrant DNA methylation pattern, has been shown to be frequently involved in sporadic breast cancer development. A growing body of literature demonstrates that combination of agents, i.e. nucleoside analogues with dietary phytochemicals, may provide enhanced therapeutic effects in epigenetic reprogramming of cancer cells. Clofarabine (2-chloro-2&#8242;-fluoro-2&#8242;-deoxyarabinosyladenine, ClF), a second-generation 2&#8242;-deoxyadenosine analogue, has numerous anti-cancer effects, including potential capacity to regulate epigenetic processes. Our present study is the first to investigate the combinatorial effects of ClF (used at IC50 concentration) with epigallocatechin-3-gallate (EGCG, tea catechin) or genistein (soy phytoestrogen), at physiological concentrations, on breast cancer cell growth, apoptosis, and epigenetic regulation of retinoic acid receptor beta (RARB) transcriptional activity. In MCF7 and MDA-MB-231 cells, RARB promoter methylation and expression of RARB, modifiers of DNA methylation reaction (DNMT1, CDKN1A, TP53), and potential regulator of RARB transcription, PTEN, were estimated using methylation-sensitive restriction analysis (MSRA) and quantitative real-time polymerase chain reaction (qPCR), respectively. The combinatorial exposures synergistically or additively inhibited the growth and induced apoptosis of breast cancer cells, followed by RARB hypomethylation with concomitant multiple increase in RARB, PTEN, and CDKN1A transcript levels. Taken together, our results demonstrate the ability of ClF-based combinations with polyphenols to promote cancer cell death and reactivate DNA methylation-silenced tumor suppressor genes in breast cancer cells with different invasive potential