GROWTH-CHARACTERISTICS OF NONMALIGNANT CELLS IN THE ATP CELL VIABILITY ASSAY

Over the last 5 years, the ATP cell viability assay (ATP-CVA) has been used to study the in vitro response of cell lines and fresh gynecolog ic human tumors to a variety of antineoplastic agents including chemot herapeutic agents, hormones and biological response modifiers. This as say measures light production as intracellular ATP interacts with the luciferin-luciferase complex. Quantitation of the light produced has b een shown to directly correspond with the number of viable cells. A pa st criticism is that in the ATP-CVA, when applied to fresh tumor tissu e, normal cells (fibroblasts, macrophages and lymphocytes) also produc e ATP, and if present in sufficient numbers, could lead to errors in c hemosensitivity testing results. This study was designed to evaluate t he growth characteristics of various benign cells found in fresh tumor s. The cells were studied under multiple plating conditions to show th e relative increase or decrease of fractional ATP measured at differen t time points. We found that agar/McCoy underlayer and agarose-coated wells do not permit the growth of nonmalignant cells. In the culture c onditions of the ATP-CVA, nonmalignant cells do not contribute relevan t ATP levels when treated samples are compared to controls on day 6. T herefore, results of the ATP-CVA in fresh tumors should not be affecte d.