Improved tumour response by laser light treatment

Abstract

Multidrug resistance (MDR) poses a serious barrier to the efficacy of clinical treatment of human cancers with chemotherapeutic drugs. This barrier might be reduced and eventually overcome by the simultaneous application of two or more treatment modalities. This study reports on the synergetic effect of combined application of laser light and cytostatic drugs to induce an improved tumour response in MDR cancer cells. The MDR breast cancer cell line MaTu/ADR, resistant to the drug adriamycin (ADR), was treated with a combination of ADR (125-1000 ng/ml) and laser light (488 nm with a total light dose between 6-18 J/cm 2 ). This combined treatment leads to an additional reduction of the cell vitality by a factor of 2-3 as compared to treatment with ADR alone, suggesting that combined application of laser light and other treatment modalities might constitute a promising strategy for improvements in the tumour response.