Altered expression of the septin gene, SEPT9, in ovarian neoplasia.

The septin family of genes has been implicated in a variety of cellular processes including cytokinesis, membrane transport and fusion, exocytosis, and apoptosis. One member of the septin family maps to chromosome 17q25.3, a region commonly deleted in sporadic ovarian and breast tumours, and has also been identified as a fusion partner of MLL in acute myeloid leukaemias. The present study demonstrates that the pattern of expression of multiple splice variants of this septin gene is altered in ovarian tumours and cell lines. In particular, expression of the zeta transcript is detectable in the majority of tumours and cell lines, but not in a range of non-malignant adult and fetal tissues. Zeta expression is accompanied by loss of the ubiquitous beta transcript. Somatic mutations of the gene were not detected in ovarian tumours, but it was demonstrated that beta expression in tumour cell lines can be reactivated by 5-azacytidine treatment, suggesting a role for methylation in the control of expression of this gene. Copyright © 2003 John Wiley & Sons, Ltd.

New perspectives on neoplasia and the RNA world

Key tenets of modern biology are the central place of protein in cell regulation and the flow of genetic information from DNA to RNA to protein. However, it is becoming increasingly apparent that genomes are much more complex than hitherto thought with remarkably complex regulatory systems. The notion that the fraction of the genome involved in coding protein is all that matters is increasingly being questioned as the roles of non-coding RNA (ncRNA) in cellular systems becomes recognised. The RNA world, including microRNA (miRNA), small inhibitory RNA (siRNA) and other RNA species, are now recognised as being crucial for the regulation of chromatin structure, gene expression, mRNA processing and splicing, mRNA stability and translational control. Furthermore such ncRNA systems may be perturbed in disease states and most notably in neoplasia, including in haematological malignancies. Here the burgeoning evidence for a role of miRNA in neoplasia is reviewed and the importance of understanding the RNA world emphasised. Copyright (c) 2005 John Wiley & Sons, Ltd.