[Ultrastructural study of the lethal effect of lymphokine activated killer (LAK) cell on liver cancer cells].

Co-cultured subcloned LAK cell and human liver cancer cell (H7402) were fixed in situ for scanning electron microscopic and transmission electron microscopic examinations. The SEM and TEM findings gave a new evidence in answering how LAK cells kill the cancer cells. First, the activated killer cells recognized and made close contact with the target cell. Then some kind of lethal hit produced by intact killer cells was delivered, injuring the target cell, boring holes and pole-like tunnels on the cell surface or even penetrating into the cytoplasm of the cancer cells. Eventually, cell death in the manner of apoptosis and necrosis occurred as the end result of the damage to the cancer cell. These findings strongly support the idea that the death of the target cells is mediated by LAK cells.