Radioimmunotherapy of human glioma xenografts in nude mice by indium-111 labelled internalising monoclonal antibody

Delivery systems exploiting natural cell transport processes of macromolecules for intracellular targeting of Auger electron emitters

The presence of Auger electrons (AE) among the decay products of a number of radionuclides makes these radionuclides an attractive means for treating cancer because these short-range electrons can cause significant damage in the immediate vicinity of the decomposition site. Moreover, the extreme locality of the effect provides a potential for selective eradication of cancer cells with minimal damage to adjacent normal cells provided that the delivery of the AE emitter to the most vulnerable parts of the cell can be achieved. Few cellular compartments have been regarded as the desired target site for AE emitters, with the cell nucleus generally recognized as the preferred site for AE decay due to the extreme sensitivity of nuclear DNA to direct damage by radiation of high linear energy transfer. Thus, the advantages of AE emitters for cancer therapy are most likely to be realized by their selective delivery into the nucleus of the malignant cells. To achieve this goal, delivery systems must combine a challenging complex of properties that not only provide cancer cell preferential recognition but also cell entry followed by transport into the cell nucleus. A promising strategy for achieving this is the recruitment of natural cell transport processes of macromolecules, involved in each of the aforementioned steps. To date, a number of constructs exploiting intracellular transport systems have been proposed for AE emitter delivery to the nucleus of a targeted cell. An example of such a multifunctional vehicle that provides smart step-by-step delivery is the so-called modular nanotransporter, which accomplishes selective recognition, binding, internalization, and endosomal escape followed by nuclear import of the delivered radionuclide. The current review will focus on delivery systems utilizing various intracellular transport pathways and their combinations in order to provide efficient targeting of AE to the cancer cell nucleus.

Radioimmunotherapy for high-grade glioma

Patients with high-grade glioma (HGG) still have a very poor prognosis. The infiltrative nature of the tumor and the inter- and intra-tumoral cellular and genetic heterogeneity, leading to the acquisition of new mutations over time, represent the main causes of treatment failure. Radioimmunotherapy represents an emerging approach for the treatment of HGG. Radioimmunotherapy utilizes a molecular vehicle (monoclonal antibodies) to deliver a radionuclide (the drug) to a selected cell population target. This review will provide an overview of preclinical and clinical studies to date and assess the effectiveness of radioimmunotherapy, focusing on possible future therapies for the treatment of HGG.