Altered glycosylation of proteins in cancer: what is the potential for new anti-tumour strategies.

It is becoming increasingly apparent that cell surface oligosaccharides play pivotal roles as recognition molecules in a range of cell communication and adhesion processes. Alterations in cellular glycosylation are also associated with diseases, including cancer, and may have functional significance. This paper gives an overview of the complex topic of cellular glycosylation mechanisms and reviews the well-documented alterations in cellular glycosylation of proteins in malignancy. One particular type of cancer-associated glycosylation change, the incomplete synthesis of O-linked glycans, is highlighted, and its possible functional significance in cancer cell metastatic mechanisms is discussed. The significance that cancer-associated changes in glycoprotein glycosylation may have in new approaches to anti-tumour therapies is explored.

N-acetylgalactosamine, N-acetylglucosamine and sialic acid expression in primary breast cancers.

Binding of the lectin from Helix pomatia (HPA), which recognises N-acetylgalactosamine and N-acetylglucosamine glycans, is a predictor of metastasis and poor prognosis in a number of human adenocarcinomas, including breast cancer. The glycoproteins to which it binds in these tumours have been only partially characterised, and the mechanisms underlying their biosynthesis remain unknown. In this study, 111 primary breast cancers were assessed for binding of HPA and labelling characteristics were compared directly with those of Dolichos biflorus agglutinin and soybean agglutinin, both of which also recognise N-acetylgalactosamine, Griffonia simplicifolia agglutinin II, which recognises N-acetylglucosamine, and Limax flavus agglutinin, Sambucus nigra agglutinin and Maackia amurensis lectin I, all of which recognise sialic acids. Results indicate that the HPA-binding partners expressed by cancer cells are predominantly N-acetylgalactosamine glycans, but some recognition of N-acetylglucosamine species is also likely. There was no evidence to support the hypothesis that overexpression of these moieties results from failure in sialylation. Alternative mechanisms, for example alterations in levels of activity of appropriate glycosyl transferases or disruption in transport and processing mechanisms leading to failure of normal chain extension of glycans may be responsible, and these are areas that warrant further investigation.

The effects of spiritual practices on recovery from substance abuse.

Twelve-step programs have stressed the importance of spiritual practices for over four decades. The spiritual principles embodied in the twelve-step programs may be key in their success of recovering addicts/alcoholics with an overall recovery rate of 34%. A literature search revealed little available data on spiritual principles and practices and their effects on long-term recovery from substance abuse. This study compared two groups of recovering addicts, those with one year of recovery and those with less than one year and a history of relapse. Spiritual practices were measured using a five-point Likert scale questionnaire. The results of the study indicated a relationship between spiritual practices and long-term recovery from substance abuse.