Genetic regulation of MUC1 alternative splicing in human tissues

The membrane mucin MUC1 is aberrantly expressed in a variety of cancers, and in stomach, it is a ligand for Helicobacter pylori where it plays a role in gastric carcinogenesis. Splicing variation, leading to a 9-amino acid insertion in the signal peptide region, was proposed to be because of a single-nucleotide polymorphism (rs4072037) at the 5′ end of exon 2, but is also reported to be cancer-associated. However, the effect of rs4072037 on this splicing event in healthy non-cancer tissues and on the additional spliceoforms of MUC1, including those lacking the polymorphic tandem repeat (TR) domain, has never been investigated. Here we show that in both foetal and adult tissues of known genotype, there is clear evidence for the role of rs4072037 in controlling alternative splicing of the 5′ exon 2 region of both full-length transcripts and those lacking the TR domain. Although there is some evidence for additional genetic and epigenetic influences, there is no indication of an effect of the TR domain on the proportions of the spliceoforms. In conclusion, over-representation of certain transcripts in tumour material cannot be evaluated without information on the SNP genotype as well

Epigenetic regulation of mucin genes in human cancers

Mucins are high molecular weight glycoproteins that play important roles in diagnostic and prognostic prediction and in carcinogenesis and tumor invasion. Regulation of expression of mucin genes has been studied extensively, and signaling pathways, transcriptional regulators, and epigenetic modification in promoter regions have been described. Detection of the epigenetic status of cancer-related mucin genes is important for early diagnosis of cancer and for monitoring of tumor behavior and response to targeted therapy. Effects of micro-RNAs on mucin gene expression have also started to emerge. In this review, we discuss the current views on epigenetic mechanisms of regulation of mucin genes (MUC1, MUC2, MUC3A, MUC4, MUC5AC, MUC5B, MUC6, MUC16, and MUC17) and the possible clinical applications of this epigenetic information

Rho-Regulatory Proteins in Breast Cancer Cell Motility and Invasion

The importance of the Rho-GTPases in cancer progression, particularly in the area of metastasis, is becoming increasingly evident. This review will provide an overview of the role of the Rho-regulatory proteins in breast cancer metastatis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44220/1/10549_2004_Article_5264599.pd