We test the effects of Oxyskyrin, a secondary metabolite of the lichen Lecanora pseudistera, on the growth of murine SV40 transformed bone blastoma cells in vitro. We find that Oxyskyrin is a potent inhibitor of growth. We also find that Oxyskyrin increases sensitivity of cells to radiation and this effect is significant at radiation intensity lower than the standard intensity of cancer radiotherapy. On the basis of this study, Oxyskyrin shows promise for combined-modality cancer treatment.
Oxyskyrin; Lecanora pseudistera; Murine SV40
Reinfection of tissue with cancer cells with acquired radioresistance during treatment is the grand challenge for cancer radiotherapy . For this reason, radiotherapy is applied in combination with chemotherapy. The most effective of chemotherapeutic drug combinations inhibit the growth of the cancer cell and also increases sensitivity of cancer cells to radiation. The radiosensitizing effect enhances radiotherapy at low radiation intensity. For this reason, radiotherapy in combination with chemotherapy (combined-modality treatment) is the best standard of care for most cancers . However, the discovery rate of effective anti-cancer drugs is very slow . We must turn to the secondary metabolites of the lichens as a domain of search for such compounds. This study explores the biological activity of Oxyskyrin, a secondary metabolite of the lichen Lecanora pseudistera.