Quantitative biochemical analysis of samples from squamous cell carcinoma

Samples of tumor, tumor stroma, and mixed tumor and stroma were microdissected from three squamous cell carcinomas, as well as from adjacent nontumor tissue and assayed for malate dehydrogenase or lactate dehydrogenase activity as indicators of the relative contribution of aerobic and anaerobic processes, respectively, to energy metabolism. Malate and lactate dehydrogenase activities were greater in tumor tissue than in tumor stroma in all three tumors. However, the magnitudes of malate and lactate dehydrogenase activities were different among the tumors, suggesting that tumors vary in the degree to which aerobic and anaerobic reactions contribute to energy production. These results indicate that a quantitative assessment of enzymes involved in energy production may be a useful probe in the understanding of tumor metabolism.