Down-regulation of BCL-2 and its prevention by interleukin-4 in cultured chronic lymphocytic leukaemia cells is a methodological artefact caused by failure of protein detection/extraction following the onset of cell death.

This article reports that down-regulation of BCL-2 and its prevention by interleukin-4 in cultured chronic lymphocytic leukaemia cells is a methodological artefact caused by failure of protein detection/extraction following the onset of cell death. Immunoblotting of whole-cell lysates prepared from cultured CLL cells showed that BCL-2 levels remained constant, irrespective of whether the cells had undergone apoptosis or whether this had been prevented by incubation with IL-4. In contrast, when protein extraction was performed by lysing the cells in radio -immunoprecipitation buffer, there was an apparent reduction in the BCL-2 levels of CLL cells cultured in the absence of IL-4.