Enzyme activities in human fetal and neoplastic tissues

Abstract

The concentrations of ten or 12 enzymes involved in the metabolism of DNA, collagen, amino acids, or glucose have been determined in variants of human intestinal and pulmonary tissues. In comparison to nonneoplastic adult colon, normal fetal colon had elevated concentrations of thymidine kinase, peptidyl proline hydroxylase, phosphoserine phosphatase, ornithine transcarbamylase, gamma-glutamyl transpeptidase, and ornithine aminotransferase. Raised activities of the first five of these enzymes, and of hexokinase, glucose-6-phosphate dehydrogenase, and pyrroline-5-carboxylate reductase distinguishes neoplastic from nonneoplastic sections of adult colon. Study of a wide range of pulmonary specimens permitted comparisons of different types of tumors, and revealed some subtle differences between lungs of noncancer patients and nonneoplastic portions of host lungs. The concentrations of eight previously identified enzymic indicators were less in moderately or well differentiated than in poorly differentiated pulmonary adenocarcinomas. The latter differed from epidermoid carcinomas (also poorly differentiated) by containing lower concentrations of thymidine kinase (both soluble and particulate) and hexokinase.

Anticarcinogenic Activity of Allylmercaptocaptopril Against Aflatoxin-B1 Induced Liver Carcinoma in Rats

“…hexokinase, phosphoglucoisomerase and aldolase in cancer induced rats. This infers that the rate of glycolysis was enhanced during tumour growth (19). There exists a direct correlation between glycolytic activity and hexokinase in a variety of tumour cell lines (20).…”

Cytofluorometric determination of thymidine kinase activity in a mixture of normal and neoplastic cells

“…The cytosolic enzyme TK1, dominates in replicating cells, but is absent in resting cells (Bello, 1974). Therefore high levels of TK1 activity are found in foetal and neoplastic cells, but its activity is low in non-growing adult tissue (Gordon et al, 1968;Herzfeld & Greengard, 1980;Bardot et al, 1991). The second type of the enzyme, TK2, is of mitochondrial origin and causes the lower and constant level of TK activity in resting cells (Adler & McAuslin, 1974).…”

Thymidine Kinase Activity in Familial Adenomatous Polyposis.

“…We Sakamoto et al (1984Sakamoto et al ( , 1985 and others (Herzfeld et al 1978 ;Herzfeld and Greengard 1980 ;Waber et al 1980Waber et al , 1981 have previously determined that total TK activity in human colon carcinoma tissue was significantly higher than that seen in normal human colon mucosa. Weber et al (1980) have reported that TK activity rises to 331% that of normal mucosa in colonic adenocarcinoma samples obtained from nine patients, and that TK activities in rapidly growing xenografts of human colon carcinoma in nude (athymic) mice were markedly higher than those in slowly growing xenografts (Weber et al 1981).…”

“…Weber et al (1980) have reported that TK activity rises to 331% that of normal mucosa in colonic adenocarcinoma samples obtained from nine patients, and that TK activities in rapidly growing xenografts of human colon carcinoma in nude (athymic) mice were markedly higher than those in slowly growing xenografts (Weber et al 1981). Furthermore, Herzfeld et al (1978), Herzfeld and Greengard (1980) have also suggested that progressive elevations in TK activity seem to correlate with increasing histological dedifferentiation of the tumor.…”