Susana Brito dos Santos

Key environmental stress biomarker candidates for the optimisation of chemotherapy treatment of leukaemia

The impact of fluctuations of environmental parameters such as oxygen and starvation on the evolution of leukaemia is analysed in the current review. These fluctuations may occur within a specific patient (in different organs) or across patients (individual cases of hypoglycaemia and hyperglycaemia). They can be experienced as stress stimuli by the cancerous population, leading to an alteration of cellular growth kinetics, metabolism and further resistance to chemotherapy. Therefore, it is of high importance to elucidate key mechanisms that affect the evolution of leukaemia under stress. Potential stress response mechanisms are discussed in this review. Moreover, appropriate cell biomarker candidates related to the environmental stress response and/or further resistance to chemotherapy are proposed. Quantification of these biomarkers can enable the combination of macroscopic kinetics with microscopic information, which is specific to individual patients and leads to the construction of detailed mathematical models for the optimisation of chemotherapy. Due to their nature, these models will be more accurate and precise (in comparison to available macroscopic/black box models) in the prediction of responses of individual patients to treatment, as they will incorporate microscopic genetic and/or metabolic information which is patient-specific.

Dynamic human erythropoiesis in a three-dimensional perfusion bone marrow biomimicry

Traditional culture systems for human erythropoiesis lack microenvironmental niches, spatial marrow gradients and dense cellularity rendering them incapable of effectively translating marrow physiology ex vivo. Herein, a bio-inspired three-dimensional (3D) perfusion bioreactor was engineered and inoculated with unselected single donor umbilical cord blood mononuclear cells (CBMNCs). Functional stromal and hematopoietic environments supporting long-term erythropoiesis were generated using defined medium supplemented only with stem cell factor (SCF) and erythropoietin (EPO) at near physiological concentrations. Quantitative 3D image analyses spatiotemporally mapped 21 multi-lineal cell distributions and interactions within multiple microenvironments that secreted extracellular matrix proteins and at least 16 endogenous hematopoietic and stromal growth factors. Tissue-like culture densities (≥2∙109 cells/mL), 1000-fold above flask cultures, were attained with continuous erythropoiesis and erythrocyte harvest. We propose this physiologically-relevant system for understanding normal and abnormal erythropoiesis, as well as for drug testing and/or discovery aimed at clinical translation.