Ida Franiak-Pietryga

PPI-G4 Glycodendrimers Upregulate TRAIL-Induced Apoptosis in Chronic Lymphocytic Leukemia Cells

Although chronic lymphocytic leukemia (CLL) is the most common adult leukemia in Western world, it remains incurable with conventional chemotherapeutic agents. Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is an antitumor candidate in cancer therapy. This study examines the proapoptotic effects of poly(propylene imine) (PPI) glycodendrimers modified with the maltotriose residues (PPI-G4-OS-Mal-III and PPI-G4-DS-Mal-III) on the TNF family in CLL cells. The combination of an understanding of the signaling pathways associated with CLL and the development of a molecular profiling is a key issue for the design of personalized approaches to therapy. Gene expression is determined with two-color microarray 8 × 60K. The findings indicate that PPI-G4-OS/DS-Mal-III affect gene expression from the TRAIL apoptotic pathway and exert a strong effect on CLL cells comparable with fludarabine. Dendrimer-targeted technology may well prove to bridge the gap between the ineffective treatment of today and the effective personalized therapy of the future.

Toward personalized therapy for chronic lymphocytic leukemia: DSC and cDNA microarray assessment of two cases.

The differences in clinical course of chronic lymphocytic leukemia could have an impact on variations in a patient’s response to therapy. Our published results revealed that thermal transition (95 ± 5°C) in differential scanning calorimetry profiles appear to be characteristic for the advanced stage of CLL. Moreover, a decrease/loss of this transition in nuclei from leukemic cells exposed to drugs ex vivo could indicate their diverse efficacy. It seems that the lack of changes in thermal profile could predict patient’s drug resistance. In this study, we demonstrate the results obtained after drug treatment of leukemic cells by calorimetry, apoptosis-related parameters involved in expression of genes using cDNA microarray and western blot. These data were compared with the patients’ clinical parameters before and after RCC therapy (rituximab + cladribine + cyclophosphamide). The complementary analysis of studied cases with opposite clinical response (CR or NR) revealed a strong relationship between clinical data, differences in thermal scans and apoptosis-related gene expression. We quantified expression of eight of apoptosis-related 89 genes, i.e., NOXA, PUMA, APAF1, ESRRBL1, CASP3, BCL2, BCL2A1 and MCL1. Particular differences in NOXA and BCL2 expression were revealed. NOXA expression in cells of patients who achieved a complete response to RCC therapy was 0.44 times higher in comparison to control ones. Interestingly, in the case of patients who did not respond to immunotherapy, NOXA expression was highly downregulated (RQ = 4.39) as compared with untreated cells. These results were confirmed by distinct cell viability, protein expression as well as by differences in calorimetry profiles.

Dendrimer-based nanoparticles for potential personalized therapy in chronic lymphocytic leukemia: Targeting the BCR-signaling pathway

Chronic lymphocytic leukemia (CLL) is one of the most prevalent forms of leukemia in western society. Although classic chemoimmune therapy is still the gold standard of care for leukemic patients, effective therapy of CLL is yet to be achieved. The present study examines the influence of poly(propylene)imine (PPI) dendrimers with primary amino surface groups modified with maltotriose residues in approximately 90% (PPI-G4-DS-Mal-III) or 30% (PPI-G4-OS-Mal-III) of cases on CLL cells (MEC-1 cell line with del(17p)), and confirms that the main trigger in this interaction is the induction of the apoptotic mechanism. The efficacy of each dendrimer was compared using fludarabine (FA). Gene expression profiling (GEP) by microarray identified a group of genes in the BCR signaling pathway characterized by different levels of expression directly associated with the tested agent and type of interaction. Network analysis revealed the potential patterns involved in potential personalized therapy of CLL. The expression of most BCR genes decreased under the influence of dendrimers, which might translate into decreased maturation and proliferation of CLL lymphocytes. Moreover, PPI-G4-OS/DS-Mal-III dendrimers affected gene expression and CLL cells in a different way to FA. Thanks to unique properties, dendrimers may be specifically targeted, thus improving the effectiveness of CLL therapy.

Blockage of Wnt/β‐Catenin Signaling by Nanoparticles Reduces Survival and Proliferation of CLL Cells In Vitro—Preliminary Study

The Wnt/β-catenin signaling pathway is shown to play a significant role in the control of the survival, proliferation, and differentiation of hematopoietic cells. Studies have confirmed that aberrant activation of canonical Wnt signaling occurs in various forms of leukemia, and is crucial for chronic lymphocytic leukemia (CLL) pathogenesis. The aim of the study is to evaluate the influence of maltotriose (M3) modified fourth generation poly(propylene imine) dendrimers (PPI-G4) on Wnt/β-catenin pathway gene expression in CLL (MEC-1) cells and to compare these findings with those obtained with fludarabine (FA). Microarray data analysis reveals seven of 19 Wnt/β-catenin pathway genes whose expression changes significantly during dendrimer and FA treatment: WNT10A, WNT6, and CDH1 among others. PPI-G4-M3 is already known to influence MEC-1 cell apoptosis and proliferation. The obtained results suggest that the reduction in cell survival under the influence of glycodendrimers and FA may be due to loss of Wnt signaling.

Changes in the apoptotic gene expression profile in CLL patients treated with rituximab combined with cladribine and cyclophosphamide-preliminary results

The study was aimed to investigate modifications of apoptotic gene expression profile by microarray technique in 10 patients with chronic lymphocytic leukemia by treatment with rituximab, cladribine and cyclophosphamide (RCC) according to IGHV mutational status. The TaqMan Low Density Array for 96 gene transcripts was used. Those modifications followed two distinctive patterns largely overlapping the IGHV mutational status. In the IGHV-mutated group, the expression of many proapoptotic genes increased after treatment as compared to initial value. Our results suggest that RCC drugs may act through influence on the expression of some apoptosis-involved genes dependently on the IGVH mutational status.

Current Knowledge of Microarray Analysis for Gene Expression Profiling in Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia (CLL) is characterised by the accumulation of mature CD5/CD19 B-lymphocytes in the blood, bone marrow, lymph nodes and spleen (Caligaris-Cappio & Hamblin, 1999). Although the role of cellular proliferation disorders in CLL may originally have been underestimated, the typical characteristic of the disease is still regarded as a failure of malignant cells to undergo apoptosis (Munk Pedersen & Reed, 2004). CLL is a heterogeneous disease and although it is relatively stable in some patients, it progresses rapidly in others (Caligaris-Cappio & Hamblin, 1999). The mutational status of immunoglobulin heavy chain variable gene segment (IGHV) and the expression of CD38 and/or ZAP70 are important prognostic factors of disease so their detection is very useful for stratification of patients into indolent or aggressive subgroups (Hamblin et al., 1999; Krober et al., 2002; Orchard et al., 2004).