Amino acids in squamous cell carcinomas and adjacent normal tissues from patients with larynx and oral cavity lesions

Abstract

Cancer patients experience metabolic disturbances that lead to nutritional status imbalance. The metabolic alterations of both host and tumor cells are predominantly caused by changes in the glucose metabolism of tumors, higher energy expenditures, decreases in ATP levels and increases in lactic acid production (1,2). Cellular amino acid contents appear to be essential for tumor growth. Theuer (3) observed that the restriction of tryptophan, threonine, leucine, methionine, phenylalanine, valine and isoleucine contributed to the control of tumor growth in rats. However, host weight was affected by tryptophan, threonine, leucine and methionine restriction. The restriction of phenylalanine and tyrosine also reduced weight, causing a loss of fat and lean body mass and an increase in white cells and neutrophils (4). Although it has been postulated that tumors utilize more amino acids than normal cells, few studies have compared the proportions of amino acids in tumor cells and paired normal tissues. Thus, the objective of the present study was to compare the amino acid content in malignant and adjacent normal tissues from the same patient.