Applications of Atomic Force Microscopy in Exploring Drug Actions in Lymphoma-Targeted Therapy at the Nanoscale

Abstract

Rituximab, a monoclonal antibody against the CD20 molecule expressed on B cells, has revolutionized the treatment of B cell lymphomas. The use of rituximab significantly improves the long-term survival rates of lymphoma patients. However, there are still many patients who develop resistance to rituximab. Hence, the urgent need is enhancing the potency of anti-CD20 antibodies beyond that achieved with rituximab to provide effective therapies for more patients. Traditional studies about the killing mechanisms of rituximab are commonly based on optical microscopy, which cannot reveal the detailed situations due to the limit of 200-nm resolution. Quantitatively investigating the actions of rituximab at the nanoscale is still scarce. The advent of atomic force microscopy (AFM) provides a powerful and versatile platform for in situ investigating the nanoscale behaviors of individual live cells. The applications of AFM in life sciences in the past decade have yielded a lot of novel insights into cell biology and related diseases. In this article, the typical applications (e.g., ultra-microstructures, mechanical properties, and molecular recognition) of AFM in investigating the three killing mechanisms of rituximab at the nanoscale are summarized; the challenges facing AFM single-cell assay and its future directions are also discussed.

Glycerol-3-phosphate acyltransferase 2 expression modulates cell roughness and membrane permeability: An atomic force microscopy study

“…On the other hand, the AFM resolution is able to reveal the presence of micro-irregularities such as pore-like structures. In this sense, pore-like structures were studied at the apical membrane of pancreatic acinar cells [ 32 ], in the outer mitochondrial membrane [ 33 ], and at the rituximab induced lysis of lymphoma cells [ 44 ]. Thus, this technique has been used to study pore presence or formation in both physiological and non-physiological conditions.…”

“…Membrane integrity is critical to cell survival and function, and a reduction in cell viability induced by pore formation is commonly observed in pathological conditions such as drug treated, malignant, or virally transformed cells [ 44 ]. Here, we observed that only sh-MDA cells exhibited pore-like structures and they were not present in GPAT2 expressing cells.…”

Quantitative characterization of cell physiological state based on dynamical cell mechanics for drug efficacy indication

“…Furthermore, cell mechanics information upon drug action can be used to characterize therapeutic effects. For instance, the quantitative measurement of the binding affinity with the antibody drug, rituximab ( Rtx ), and the visualization of nanoscale distribution of the target antigens on the cells, both CD20s on lymphoma cancer B cells and FcRs on natural killer cells, indicate that the antigen-antibody binding forces and the organization of the target molecules on the cells have significant impact on the therapeutic effect of B-cell non-Hodgkin's lymphoma [ 23 , 31 , 32 ], and the cellular surface roughness and cellular mechanical properties can be used to quantify the synergistic interactions between targeted drugs and chemotherapy drugs and to predict the efficacy of combinatorial drugs, cisplatin, cytarabine, and Rtx [ 30 ]. Therefore, the study on cellular mechanics of cancers can advance our understanding of pathological processes of diseases and allow for evaluating drug efficacies in cancer treatments at the single-cell scale.…”

Applications of Micro/Nano Automation Technology in Detecting Cancer Cells for Personalized Medicine

“…An example is rituximab (a monoclonal antibody approved in 1997 by US Food and Drug Administration) in the therapy of B-cell non-Hodgkin lymphoma. The binding of rituximab to the CD20s on the lymphoma cell can cause the death of lymphoma cell via three main mechanisms [20], including directly inducing cell apoptosis, causing cell lysis via complement system, and recruiting effector cells (e.g., macrophage and NK cell) to attack tumor cells. Various molecular interactions take place during the actions of rituximab.…”