Influence of malignancy and cyctostatic treatment on microcalorimetric behaviour of urological tissue samples and cell cultures

Abstract Microcalorimetry allows direct, continuous measurement of metabolic rate in tissue samples and cell cultures. In the oncological field, it may complement morphological tumour grading by information on the “biological activity” of tumour material. However, calorimetry, although widely accepted in haematological research, has up to now rarely been used in the study of solid tumours. In this investigation 44 tumorous and non-tumorous tissue samples of various urological organs and 10 cell lines, cultured in RPMI 1640 medium, from patients with renal cell carcinomas were measured in a microcalorimeter to study the metabolic activity and the responsiveness to cytostatic treatment. The determination of the maxima ( P max ) and the mean values ( P ), and the contour integrals ( W ) of the measured heat evolution shows a distinctly higher metabolic activity of tumorous than of non-tumorous material. We conclude that through microcalorimetric analysis, it is possible to differentiate between healthy and tumorous tissue samples on the basis of a varyingly higher metabolic activity of the malignant samples. The renal cell carcinoma lines were incubated without and with the cytostatic drug (5-fluorouracil) and with two “biological response modifiers” (alpha-interferon-2a and interleukin-2). We found that untreated cell lines, which showed a high increase in heat production, react more sensitively to the antimetabolic agent and that in all cases the combination of 5-fluorouracil with alpha-interferon-2a creates an improved cytostatic effect.