Enzymatic characteristics of tubular adenomas and carcinomas of the large intestine.

Abstract

SUMMARY Enzyme activities in homogenates of the large intestine were measured in biopsies from 11 tubular adenomas and six carcinomas and from the corresponding normal mucosa of each individual. A similar and significant increase was found in the total activities of glucose-6-phosphate dehydrogenase (G 6 PD) Received for publication 14 August 1981 As far as we know enzyme activities have not been measured in homogenates from tubular adenomas of the colon. The present study was carried out in order to see whether the above-mentioned difference in prognosis of tubular adenomas might be apparent from a shift in their enzyme patterns. MethodsPolyps were removed by sling resection, and biopsies from carcinomas and, for comparison, from normal mucosa were taken during routine colonoscopy. Biopsies from the normal mucosa were always taken more than 5 cm from the tumour. The specimens were quenched. When kept on ice, the polyps were cut, and two pieces from the parietal part of the polyp and samples from the other materials were stored within two hours at -70°C.

Differential expression proteomics of human colon cancer

“…Although the mRNAs specifying I-and L-FABP are among the most abundant sequences that accumulate in the small intestinal epithelium (8,37), it is unclear why the intestine requires the expression of two cytosolic FABPs. Gang and Ockner (34) have shown that in the intestine, luminally derived fatty acids are largely reesterified in the enterocyte to form triacylglycerol, whereas fatty acids derived from the intestinal blood supply are utilized for energy production and phospholipid biosynthesis (75). One attractive but unproven hypothesis is that the two FABPs contribute to this metabolic compartmentalization.…”

Colonic Adenoma: Natural History

“…Similarly, an increase in the M/H ratio of LD isoenzyme in colorectal carcinoma and adjacent tissue [39] has been shown also in homogenates of tubular adenomas with moderate dysplasia [40]. Cytoplasmic en zyme patterns in tubular adenomas are simi lar to those seen in cancer [40,41 ].…”

“…Cytoplasmic en zyme patterns in tubular adenomas are simi lar to those seen in cancer [40,41 ]. Increased activity of enzyme markers of malignancy, independent of size of polyps and growth rate, has been shown, both for adenomas compared to hyperplastic polyps and for ad enomas with moderate compared to mild dysplasia [37].…”