Replication-independent nucleosome exchange is enhanced by local and specific acetylation of histone H4.

We used a novel single-cell strategy to examine the fate of histones during G(2)-phase. Consistent with previous results, we find that in G(2)-phase, the majority of nuclear histones are assembled into chromatin, whereas a small fraction comprises an unassembled pool. Small increases in the amount of histones within the free pool affect the extent of exchange, suggesting that the free pool is in dynamic equilibrium with chromatin proteins.

Quantitative profiling of CpG island methylation in human stool for colorectal cancer detection.

Purpose: The aims of this study were to investigate the use of quantitative CGI methylation data from stool DNA to classify colon cancer patients and to relate stool CGI methylation levels to those found in corresponding tissue samples.

Methods: We applied a quantitative methylation-specific PCR assay to determine CGI methylation levels of six genes, previously shown to be aberrantly methylated during colorectal carcinogenesis. Assays were performed on DNA from biopsies of "normal" mucosa and stool samples from 57 patients classified as disease-free, adenoma, or cancer by endoscopy, and in tumour tissue from cancer patients.

Recent advances in understanding the role of diet and obesity in the development of colorectal cancer.

Colorectal cancer (CRC) is a major cause of premature death in the UK and many developed countries. However, the risk of developing CRC is well recognised to be associated not only with diet but also with obesity and lack of exercise. While epidemiological evidence shows an association with factors such as high red meat intake and low intake of vegetables, fibre and fish, the mechanisms underlying these effects are only now being elucidated.

Use of DNA from human stools to detect aberrant CpG island methylation of genes implicated in colorectal cancer.

Hypermethylation of cytosine residues in the CpG islands of tumor suppressor genes is a key mechanism of colorectal carcinogenesis. Detection and quantification of CpG island methylation in human DNA isolated from stools might provide a novel strategy for the detection and investigation of colorectal neoplasia. To explore the feasibility of this approach, colorectal biopsies and fecal samples were obtained from 32 patients attending for colonoscopy or surgery, who were found to have adenomatous polyps, colorectal cancer, or no evidence of neoplasia.

Occurrence of proteinaceous endoxylanase inhibitors in cereals.

Cereals contain proteinaceous inhibitors of endoxylanases, which affect the efficiency and functionality of these enzymes in cereal processing. This review relates their first discovery in wheat and the subsequent purification of two distinct classes of endoxylanase inhibitors, namely Triticum aestivum xylanase inhibitor (TAXI)-type and xylanase inhibitor protein (XIP)-type inhibitors in cereals. Both inhibitor classes occur in monocots as multi-isoform families.

A family 11 xylanase from Penicillium funiculosum is strongly inhibited by three wheat xylanase inhibitors.

Steady-state kinetic approaches were used to investigate the binding of a novel Penicillium funiculosum xylanase, XYNC, with three known xylanase inhibitor proteins from wheat (Triticum aestivum). The xylanase gene (xynC) was cloned from a P. funiculosum genomic library and the deduced amino acid sequence of XYNC exhibited high sequence similarity with fungal family 11 xylanases.

Functional identification of the cDNA coding for a wheat endo-1,4-beta-D-xylanase inhibitor.

Using expressed sequence tag data, we obtained a full-length cDNA encoding a wheat protein inhibitor of xylanases (XIP-I). The 822 bp open reading frame encoded a protein of 274 amino acids with a molecular mass of 30.2 kDa, in excellent agreement with the native protein.