Lycopene affects proliferation and apoptosis of four malignant cell lines.

The beneficial effect of lycopene from tomatoes on a variety of chronic diseases and particularly its association with decreased incidence of prostate and breast cancer seems to be well established. The aim of the study was to examine its anti-proliferative and apoptotic effect on other malignant cell lines. Cells of the following lines were incubated with 1.0, 2.0, and 4.0microM of lycopene: human colon carcinoma (HuCC), B chronic lymphocytic leukemia (EHEB), human erythroleukemia (K562) and Raji, a prototype of Burkitt lymphoma cell line. The results showed that lycopene exerted a significant dose-dependent effect on the proliferation capacity of K562, Raji and HuCC lines, whereas this effect was observed in EHEB cells only with the highest dose used in the study. Increased apoptotic rate was found after incubation of HuCC cells with 2.0 and 4.0microM of lycopene and in Raji cells following incubation with 2.0microM. The findings point out that the anti-proliferative effect of lycopene on tumor cells and its effect on the apoptotic rate depends on its dosage and on the type of the malignant cells.