Relationship between nutritional habits adopted by ulcerative colitis relevant to cancer development patients at clinical remission stages and molecular-genetic parameters.

UC (ulcerative colitis) patients have an increased risk of developing colorectal cancer compared with the normal population. The cause underlying this higher risk is not fully defined but includes nutritional and environmental factors concomitant with genetic alterations. We aimed to evaluate genetic stability in the colonic tissue of UC patients in clinical remission compared with the healthy population, and to establish a possible correlation between nutritional habits and these molecular assessments. UC patients (n 42) and healthy controls (n 37) participated in the study. All participants were histopathologically and medically diagnosed. Participants completed five separate 7 d dietary records, food-frequency questionnaires and validated 24 h recalls for nutritional assessment. The extent of chromosome 17 loss and the calculated chromosome index was determined in colon tissue biopsies by fluorescence in situ hybridisation. Correlations between the molecular and nutritional assessments were performed using Pearson's correlation coefficients. Significant differences in the nutritional intake of total fat (65 (SD 15) v. 89 (SD 25) g), cholesterol (330 (SD 168) v. 464 (SD 177) mg), dietary fibre (32 (SD 4.7) v. 9 (SD 4) g), vitamin A (1009 (SD 209) v. 506 (SD 204) microg), vitamin C (308 (SD 108) v. 72 (SD 53) mg) and folic acid (412 (SD 89 microg) v. 187 (SD 107)) were recorded for UC patients compared with controls. Significant correlations were found for the consumption of different food groups and the chromosome index for chromosome 17. The results of our study suggest that the nutritional habits adopted by UC patients during clinical remission may affect key cellular components of the colonic tissue, inducing a high degree of aneuploidy and genetic instability, and probably affecting the development of colon cancer.

A high degree of aneuploidy, loss of p53 gene, and low soluble p53 protein serum levels are detected in ulcerative colitis patients.

PURPOSE: The causes for the increased risk of colorectal cancer associated with ulcerative colitis have not been fully defined. Colonic tissue of ulcerative colitis patients was examined for changes in chromosome-17-centromere copy number, loss of the p53 gene, and alterations in serum levels of the 53-kDa protein. This study was performed under the assumption that these molecular events correlate with ulcerative colitis status and duration. METHODS: Ulcerative colitis patients (n = 42) and healthy controls (n = 37) participated in the study. All participants were histopathologically and medically diagnosed. The stage of ulcerative colitis patients was stratified according to increasing risk factors for the development of colorectal cancer: left-sided colitis, pancolitis, sclerosing cholangitis, and dysplasia-associated lesions or masses. Changes in centromere number of chromosome 17 alone or in association with changes in copy number of the p53 gene were analyzed in colon tissue biopsies by fluorescence in situ hybridization. Serum p53 level was determined in blood samples by immunoprecipitation followed by separation using high-pressure liquid chromatography. RESULTS: Changes in chromosome 17 and p53 copy number and lower levels of serum p53 protein in ulcerative colitis patients directly correlated with colorectal cancer risk factors. All values significantly differed from controls. Significant direct correlations were obtained for ulcerative colitis disease duration, levels of p53 in the serum, and extent of aneuploidy. CONCLUSIONS: We demonstrate that in the colonic mucosa of ulcerative colitis patients, high levels of genomic instability, changes in p53 gene copy number, and lower levels of p53 in the serum directly correlate with the extent of disease duration and increased risk factors for colorectal cancer. Any of the measurements described herein can provide an acceptable prognostic tool in the assessment of colorectal cancer risk in ulcerative colitis patients.

Thiol-activated serine proteinases from nymphal hemolymph of the African migratory locust, Locusta migratoria migratorioides.

Two unique serine proteinase isoenzymes (LmHP-1 and LmHP-2) were isolated from the hemolymph of African migratory locust (Locusta migratoria migratorioides) nymphs. Both have a molecular mass of about 23 kDa and are activated by thiol-reducing agents. PMSF abolishes enzymes activity only after thiol activation, while the cysteine proteinase inhibitors E-64, iodoacetamide, and heavy metals fail to inhibit the thiol-activated enzymes. The N-terminal sequence was determined for the more-abundant LmHP-2 isoenzyme. It exhibits partial homology to that of other insect serine proteinases and similar substrate specificity and inhibition by the synthetic and protein trypsin inhibitors pABA, TLCK, BBI, and STI. The locust trypsins LmHP-1 and LmHP-2 constitute a new category of serine proteases wherein the active site of the enzyme is exposed by thiol activation without cleavage of peptide bonds.

Jojoba seed meal proteins associated with proteolytic and protease inhibitory activities.

The jojoba, Simmondsia chinensis, is a characteristic desert plant native to the Sonoran desert. The jojoba meal after oil extraction is rich in protein. The major jojoba proteins were albumins (79%) and globulins (21%), which have similar amino acid compositions and also showed a labile thrombin-inhibitory activity. SDS-PAGE showed two major proteins at 50 kDa and 25 kDa both in the albumins and in the globulins. The 25 kDa protein has trypsin- and chymotrypsin-inhibitory activities. In vitro digestibility of the globulins and albumins resembled that of casein and soybean protein concentrates and was increased after heat treatment. The increased digestibility achieved by boiling may be attributed to inactivation of the protease inhibitors and denaturation of proteins.