Raman Spectroscopy as a Research and Diagnostic Tool in Clinical Hematology and Hematooncology.

Raman spectroscopy is a molecular spectroscopic technique able to provide detailed information about the chemical structure, phase, crystallinity, and molecular interactions of virtually any analyzed sample. Although its medical applications have been studied for several decades, only recent advances in microscopy, lasers, detectors, and better understanding of the principles of the Raman effect have successfully expanded its applicability to clinical settings. The promise of a rapid, label-free diagnostic method able to evaluate the metabolic status of a cell in vivo makes Raman spectroscopy particularly attractive for hematology and oncology. Here, we review widely studied hematological applications of Raman spectroscopy such as leukocyte activation status, evaluation of treatment response, and differentiation between cancer and non-malignant cells, as well as its use in still unexplored areas in hematology. We also discuss limitations and challenges faced by Raman spectroscopy-based diagnostics as well as recent advances and modifications of the method aimed to increase its applicability to clinical hematooncology.

Cytotoxic Potential of Bioactive Compounds from Aspergillus flavus, an Endophytic Fungus Isolated from Cynodon dactylon, against Breast Cancer: Experimental and Computational Approach.

Endophytic fungi are a diverse group of microorganisms that colonize the inter- or intracellular spaces of plants and exhibit mutual benefits. Their interactions with the host plant and other microbiomes are multidimensional and play a crucial role in the production of secondary metabolites. We screened bioactive compounds present in the extracts of Aspergillus flavus, an endophytic fungus isolated from the roots of the medicinal grass Cynodon dactylon, for its anticancer potential. An in vitro analysis of the Ethyl acetate extract from A. flavus showed significant cytostatic effects (IC50: 16.25 µg/mL) against breast cancer cells (MCF-7). A morphological analysis of the cells and a flow cytometry of the cells with annexin V/Propidium Iodide suggested that the extract induced apoptosis in the MCF-7 cells. The extract of A. flavus increased reactive oxygen species (ROS) generation and caused a loss of mitochondrial membrane potential in MCF-7 cells. To identify the metabolites that might be responsible for the anticancer effect, the extract was subjected to a gas chromatography-mass spectrometry (GC-MS) analysis. Interestingly, nine phytochemicals that induced cytotoxicity in the breast cancer cell line were found in the extract. The in silico molecular docking and molecular dynamics simulation studies revealed that two compounds, 2,4,7-trinitrofluorenone and 3α, 5 α-cyclo-ergosta-7,9(11), 22t-triene-6beta-ol exhibited significant binding affinities (-9.20, and -9.50 Kcal/mol, respectively) against Bcl-2, along with binding stability and intermolecular interactions of its ligand-Bcl-2 complexes. Overall, the study found that the endophytic A. flavus from C. dactylon contains plant-like bioactive compounds that have a promising effect in breast cancer.

Dynamic Changes in the Ability to Release Neutrophil ExtraCellular Traps in the Course of Childhood Acute Leukemias.

Acute leukemias, the most common cancers in children, are characterized by excessive proliferation of malignant progenitor cells. As a consequence of impaired blood cell production, leukemia patients are susceptible to infectious complications-a major cause of non-relapse mortality. Neutrophil extracellular traps (NETs) are involved in various pathologies, from autoimmunity to cancer. Although aberrant NETs formation may be partially responsible for immune defects observed in acute leukemia, still little is known on the NET release in the course of leukemia. Here, we present the first comprehensive evaluation of NETs formation by neutrophils isolated from children with acute leukemia in different stages of the disease and treatment stimulated in vitro with phorbol 12-myristate 13-acetate (PMA), N-formyl-methionyl-leucyl-phenylalanine (fMLP), and calcium ionophore (CI). NETs release was measured using quantitative fluorescent method and visualized microscopically. In this setting, NETs release was significantly impaired in leukemic children both at the diagnosis and during the treatment, and full restoration of neutrophil function was achieved only after successful completion of the leukemia treatment. We suggest that neutrophil function impairment may result from both disease- and treatment-related factors. In this context, deficient innate immune response observed in acute leukemia patients may be present regardless of neutrophil count and contribute to secondary immunodeficiency observed in this population.

Discovery of 5-naphthylidene-2,4-thiazolidinedione derivatives as selective HDAC8 inhibitors and evaluation of their cytotoxic effects in leukemic cell lines.

Histone deacetylases (HDACs) are being explored as a therapeutic target for interventions in different types of cancer. HDAC8 is a class I HDAC that is implicated as a therapeutic target in various indication areas, including different types of cancer and particularly childhood neuroblastoma. Most previously described HDAC8-selective inhibitors contain a hydroxamate function as zinc binding group (ZBG) to confer potency. However, hydroxamate class HDAC inhibitors have raised increasing concerns about their mutagenic character. Therefore, non-hydroxamate based inhibitors could prove to be safer than hydroxamates. In the present work, a series of novel 5-naphthylidene-2,4-thiazolidinedione was designed and evaluated as potential antiproliferative agents targeting selectively HDAC8 enzyme. Eleven novel derivatives were synthesized, purified and characterized by spectroscopic techniques. Compounds 3k and 3h was found to be most potent selective inhibitors of HDAC8 with IC50 values of 2.7 µM and 6.3 µM respectively. 3a to 3i was found to be most cytotoxic in leukemic cell lines. 3a and 3 h both were found to induce apoptosis and cause cell cycle arrest in G2/M phase.

Discovery of novel N-substituted thiazolidinediones (TZDs) as HDAC8 inhibitors: in-silico studies, synthesis, and biological evaluation.

Epigenetics plays a fundamental role in cancer progression, and developing agents that regulate epigenetics is crucial for cancer management. Among Class I and Class II HDACs, HDAC8 is one of the essential epigenetic players in cancer progression. Therefore, we designed, synthesized, purified, and structurally characterized novel compounds containing N-substituted TZD (P1-P25). Cell viability assay of all compounds on leukemic cell lines (CEM, K562, and KCL22) showed the cytotoxic potential of P8, P9, P10, P12, P19, and P25. In-vitro screening of different HDACs isoforms revealed that P19 was the most potent and selective inhibitor for HDAC8 (IC50 - 9.3 µM). Thermal shift analysis (TSA) confirmed the binding of P19 to HDAC8. In-vitro screening of all compounds on the transport activity of GLUT1, GLUT4, and GLUT5 indicated that P19 inhibited GLUT1 (IC50 - 28.2 µM). P10 and P19 induced apoptotic cell death in CEM cells (55.19% and 60.97% respectively) and P19 was less cytotoxic on normal WBCs (CC50 - 104.2 µM) and human fibroblasts (HS27) (CC50 - 105.0 µM). Thus, among this novel series of TZD derivatives, compound P19 was most promising HDAC8 inhibitor and cytotoxic on leukemic cells. Thus, P19 could serve as a lead for further development of optimized molecules with enhanced selectivity and potency.

Alterations in lipid metabolism accompanied by changes in protein and carotenoid content as spectroscopic markers of human T cell activation.

This work aims to understand better the mechanism of cellular processes accompanying the activation of human T cells and to develop a novel, fast, label-free approach to identify molecular biomarkers for this process. The standard methodology for confirming the activation state of T cells is based on flow cytometry and using antibodies recognizing activation markers. The method provide high specificity detection but may be susceptible to background staining or non-specific secondary antibody reactions. Here, we evaluated the potential of Raman-based molecular imaging in distinguishing non-activated and activated human T cells. Confocal Raman microscopy was performed on T cells followed by chemometrics to obtain comprehensive molecular information, while Stimulated Raman Scattering imaging was used to quickly provide high-resolution images of selected cellular components of activated and non-activated cells. For the first time, carotenoids, lipids, and proteins were shown to be important biomarkers of T-cell activation. We found that T-cell activation was accompanied by lipid accumulation and loss of carotenoid content. Our findings on the biochemical, morphological, and structural changes associated with activated mature T cells provide insights into the molecular changes that occur during therapeutic manipulation of the immune response. The methodology for identifying activated T cells is based on a novel imaging method and supervised and unsupervised chemometrics. It unambiguously identifies specific and unique molecular changes without the need for staining, fixation, or any other sample preparation.

Automatic subtyping of Diffuse Large B-cell Lymphomas (DLBCL): Raman-based genetic and metabolic classification.

Diffuse large B-cell lymphoma (DLBCL), the most common non-Hodgkin's lymphoma in adults, is a genetically and metabolically heterogeneous group of aggressive malignancies. The complexity of their molecular composition and the variability in clinical presentation make clinical diagnosis and treatment selection a serious challenge. The challenge is therefore to quickly and correctly classify DLBCL cells. In this work, we show that Raman imaging is a tool with high diagnostic potential, providing unique information about the biochemical components of tumor cells and their metabolism. We present models of classification of lymphoma cells based on their Raman spectra. The models automatically and efficiently identify DLBCL cells and assign them to a given cell-of-origin (COO) subtype (activated B cell-like (ABC) or germinal center B cell-like (GCB)) or, respectively, to a comprehensive cluster classification (CCC) subtype (OxPhos/non-OxPhos). In addition, we describe each lymphoma subtype by its unique spectral profile, linking it to biochemical, genetic, or metabolic features.

Effect of substrate stiffness on the osteogenic differentiation of bone marrow stem cells and bone-derived cells.

There is a profound dependence of cell behaviour on the stiffness of its microenvironment. To gain a better understanding of the regulation of cellular differentiation by mechanical cues, we investigated the influence of matrix stiffness (E = 1.46 kPa and E = 26.12 kPa) on differentiated osteogenic cell lineage of bone marrow stem cells (BM-MSCs) and bone-derived cells (BDCs) using flexible collagen-coated polyacrylamide substrates. Differentiation potential was determined by measuring alkaline phosphatase activity, expression of osteoblast-specific markers including alkaline phosphatase, osteocalcin, Runx2 and collagen type I, as well as assessment of mineralisation (Alizarin Red S staining). We found that osteogenic differentiation can be regulated by the rigidity of the substrate, which may depend on the commitment in multi- or uni-potent targeting cells. Osteogenic differentiation of BM-MSCs was enhanced on a stiff substrate compared to a soft one, whereas BDCs osteogenic differentiation did not vary depending on the substrate stiffness. The data help in understanding the role of the external mechanical determinants in stem cell differentiation, and can also be useful in translational approach in functional tissue engineering.

[Selected, biochemical markers of hypoxia]. / Wybrane, biochemiczne markery hipoksji.

Although tissues may exist regardless of reduced oxygen pressure, this requires glycolytic ATP generation, which is very expensive from the energetic viewpoint. Hypoxia is defined as the condition in which oxygen pressure is reduced at the level of bodily tissues. There are many clinical situations during which decreased tissue oxygenation may occur. It may be transient or chronic, as well as systemic or local. An emergent need exists for monitoring and diagnosis with respect to numerous possible clinical circumstances leading to hypoxia and its life-threatening consequences. The assessment of global oxygen homeo-stasis relies on blood gas analysis and lactate concentration, but such an approach does not fully reflect the local oxygenation of tissues. Oxygen needle microelectrode measurements reveal great differences in tissue pO2 levels. Local pO2 levels depend on many factors, among which the most important are: the distance to the nearest capillary, the extracellular and intracellular fluid diffusion rates and intracellular measurements of the number and activity levels of mitochondria. Thus, nowadays, it is impossible to establish an accurate normal value ranges for local tissue pO2. Oxygen deficiency is an important gene regulator. A sequence-specific DNA-binding factor, the hypoxia induced factor (HIF), is the fundamental hypoxia response protein. 70 genes identified so far have been found to be HIF-dependent. They are responsible for increased oxygen delivery, i.e. by boosting angiogensis due to vascular endothelial growth factor (VEGF) release and the enhancement of red blood cell production by erythropoietin (EPO). VEGF-induced angiogenesis is one of several key hypoxia adaptations. An enhanced vascular bed in response to hypoxia affects almost every bodily tissue and organ. This was observed particularly in skeletal muscles as well as in the brain. The expression of a few hypoxia markers does not require HIF activation. An especially interesting member of this group is osteopontin (OPN), whose synthesis increases during hypoxia. OPN was originally linked to bone remodeling, but currently it seems to posses an important role in immunity, inflammation and tumor pathogenesis. Quantification of hypoxia is clinically essential both for therapy and prognosis. Taking account of the fact that the concept of oxygen pressure at the tissue level is not quantitative (norms do not exist, results are incomparable), biochemical markers are preferable. Particularly significant in this context are hypoxia-induced proteins such as HIF, EPO, VEGF or potentially OPN.

l-Ornithine-N5-monooxygenase (PvdA) Substrate Analogue Inhibitors for Pseudomonas aeruginosa Infections Treatment: Drug Repurposing Computational Studies.

Pseudomonas aeruginosa is an opportunistic pathogen that can cause acute and severe infections. Increasing resistance to antibiotics has given rise to the urgent need for an alternative antimicrobial agent. A promising strategy is the inhibition of iron sequestration in the bacteria. The current work aimed to screen for inhibitors of pyoverdine-mediated iron sequestration in P. aeruginosa. As a drug target, we choose l-ornithine-N5-monooxygenase (PvdA), an enzyme involved in the biosynthesis of pyoverdine that catalyzes the FAD-dependent hydroxylation of the side chain amine of ornithine. As drug repurposing is a fast and cost-efficient way of discovering new applications for known drugs, the approach may help to solve emerging clinical problems. In this study, we use data about molecules from drug banks for screening. A total of 15 drugs that are similar in structure to l-ornithine, the substrate of PvdA, and 30 drugs that are sub-structures of l-ornithine were virtually docked against PvdA. N-2-succinyl ornithine and cilazapril were found to be the top binders with a binding energy of -12.8 and -9.1 kcal mol-1, respectively. As the drug-likeness and ADME properties of the drugs were also found to be promising, molecular dynamics studies were performed to further confirm the stability of the complexes. The results of this in silico study indicate that N-2-succinyl ornithine could potentially be explored as a drug for the treatment of P. aeruginosa infections.