One of the biggest problems in the current treatment of cancer is that the agents that are efficacious in the destruction of tumorous cells are, at the same time, extremely toxic for the rest of the healthy cells and tissues of the patient.
To address the problem the University of the Basque Country (UPV/EHU) is seeking more specific treatments and studying the differences between tumorous cells and healthy ones.
A research team from the Faculty of Medicine and Odontology is working on identifying pharmacological agents that increase the therapeutic benefit of combinations of chemo-, immune and radiotherapy agents in the treatment of cancer ailments.
The aim of the research team was to identify compounds that act on the metabolic pathways and processes that take place differently depending whether a diseased tissue of a patient or healthy tissue is involved; in this way selective action can be undertaken, increasing the sensitivity of treatments for diseased tissues without damaging healthy cells or tissues at the same time.
With this general goal the researchers tested various biomodulators on a number of different tumorous modules such as melanoma, sarcoma and cancer of the colon. On the one hand, they studied agents that modulated levels of glutathione (GSH) – key element in the biological processes of cells, both healthy and tumorous. Tumorous cells with high GSH levels have a greater growth and metastatic capacity and a lower sensitivity to antitumorous agents. On the other hand, one of the features of tumorous cells is that they lose their normal level of differentiation and, instead of exercising a determined function, they start to proliferate and generate a greater quantity of tumorous cells. This is why the researchers have also used agents that induce differentiation, such as are retinoids.
More selective therapies
Both groups of modulators have been associated with classic agents used in antitumorous therapies and have seen the benefits arising therefrom. They have shown that the GSH level modulating agent - oxothiazolidine-carboxylate (OTZ) increases the antitumorous effect in antitumorous cells and, at the same time, protects healthy tissue. In this way the therapeutic benefit can be increased. Nevertheless, when another GSH-level modulating agent is combined with antitumorous agents, for example, buthionine-sulphoxamide (BSO), the researchers observed that the effect of the standard drug was increased but that an increase in damage to healthy tissue also took place.