Multiplication of human NHIK 3025 cells exposed to porphyrins in combination with light.

Cells from the established line NHIK 3025 were exposed to haematoporphyrin derivative and light. After this photodynamic treatment the first interphase of surviving cells was prolonged. Furthermore, a pronounced effect on the progression through the first mitosis was observed. Mainly the duration of metaphase was increased. Some of the cells were irreversibly arrested in mitosis and the cells that were able to complete mitosis after treatment multiplied in the subsequent generations at the same rate as the control. Cells treated in the late stages of the mitosis went out of mitosis at the same rate as the control. This indicates that the treatment with porphyrins and light induces a block in a specific stage of mitosis.