Generation of an in vitro Intratumoral Heterogeneity Model by Lentiviral Fluorescent Labeling of Colon Cancer Cell Line DLD-1 Subclones

Purpose: Studying genomic changes during tumor progression has helped to understand the biology of many different cancers and has been the basis for targeted therapy strategies. However, resistance and differences in response to therapy in patients are still very important issues. One of the major underlying reasons is intratumoral cellular heterogeneity. Clones harbor mutations and/or epigenetic patterns providing a survival advantage under changing micro-environmental conditions are the main culprits of therapy resistance. Therefore, it is crucial to define and to study the properties and the contributions of these deviant subclones in vitro. In order to achieve that, we have generated a fluorescent intratumoral heterogeneity model of the colon cancer cell line DLD-1

Acrylamide-encapsulated glucose oxidase inhibits breast cancer cell viability

Geyik, Oyku Gonul/0000-0003-3014-1253; KILINC, ALI/0000-0002-0470-4297; Yuce, Zeynep/0000-0002-2762-0942WOS:000603517600022Objectives: Cancer cells modulate metabolic pathways to ensure continuity of energy, macromolecules and redoxhomeostasis. Although these vulnerabilities are often targeted individually, targeting all with an enzyme may prove a novel approach. However, therapeutic enzymes are prone to proteolytic degradation and neutralizing antibodies leading to a reduced half-life and effectiveness. We hypothesized that glucose oxidase (GOX) enzyme that catalyzes oxidation of glucose and production of hydrogen peroxide, may hit all these targets by depleting glucose; crippling anabolic pathways and producing reactive oxygen species (ROS); unbalancing redox homeostasis. Methods: We encapsulated GOX in an acrylamide layer and then performed activity assays in denaturizing settings to determine protection provided by encapsulation. Afterwards, we tested the effects of encapsulated (enGOX) and free (fGOX) enzyme on MCF-7 breast cancer cells. Results: GOX preserved 70% of its activity following encapsulation. When fGOX and enGOX treated with guanidinium chloride, fGOX lost approximately 72% of its activity, while enGOX only lost 30%. Both forms demonstrated remarkable resilience against degradation by proteinase K and inhibited viability of MCF-7 cells in an activity-dependent manner. Conclusions: Encapsulation provided protection to GOX against denaturation without reducing its activity, which would prolong half-life of the enzyme when administered intravenously