Analysis of cell proliferation and cell death during in situ hyperthermic treatment of neoplastic cells: a case report of human non-Hodgkin lymphoma

In this study we observed the effects in vivo of hyperthermic treatment on the cell kinetics (cell proliferation/cell death) in one case of human non-Hodgkin lymphoma, by analyzing the following morpho-cytochemical parameters: Acridine Orange fluorochromasia, mitotic index, proliferating cell nuclear antigen (PCNA) expression, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) labeling, and ultrastructure morphology. After two hyperthermic exposures there was a significant reduction of cell growth rate (e.g. mitotic and PCNA positive cells) and an increase in cell loss by death. The cell death occurred by the typical apoptotic cascade, namely DNA fragmentation, chromatin hypercondensation and margination, karyorrhexis, ribonucleoproteins segregation and cytoplasm cleavage; in addition some necrotic cells were found. The data indicates that the hyperthermic treatments limit the cell proliferation (e.g. arrest and/or deceleration of the cell cycle) by facilitating the trigger of programmed cell death. It was concluded that thermal injury can be considered an effective inducer of antiproliferative and apoptogenic associated effects on the growth of this kind of neoplasia.