Assessment of cell death mechanisms triggered by 177Lu-anti-CD20 in lymphoma cells.

The aim of this research was to evaluate the cell cycle redistribution and activation of early and late apoptotic pathways in lymphoma cells after treatment with 177Lu-anti-CD20. Experimental and computer models were used to calculate the radiation absorbed dose to cancer cell nuclei. The computer model (Monte Carlo, PENELOPE) consisted of twenty spheres representing cells with an inner sphere (cell nucleus) embedded in culture media. Radiation emissions of the radiopharmaceutical located in cell membranes and in culture media were considered for nuclei dose calculations. Flow cytometric analyses demonstrated that doses as low as 4.8Gy are enough to induce cell cycle arrest and activate late apoptotic pathways.