Minichromosome maintenance (MCM) proteins may be pre-cancer markers.

Abstract

Aberrant overexpression of proteins called minichromosome maintenance (Mcm) proteins at the mucosal surface of dysplastic oesophageal squamous epithelium and Barrett's mucosa may indicate proliferation potential Oesophageal cancer contributes about 3% of the cancer burden in the UK, 5% of cancer mortality, and the five year survival is a dismal 6% (www.crc.org.uk). There are two major types of oesophageal carcinoma, squamous cell carcinoma (SCC) and adenocarcinoma, each with different risk factors and epidemiologies. SCC arises from squamous cells lining the oesophagus and the geographical distribution of the disease shows wide variations, being virtually unknown in North Africa but common, for example, in eastern Turkey, Iraq, Iran, and northern China; high risk areas are generally associated with local food preservation practices that favour the generation of nitroso compounds from mould growing on pickled vegetables. In Western populations, heavy alcohol and cigarette consumption are well known risk factors for oesophageal SCC. Most adenocarcinomas on the other hand appear to arise from within areas of metaplasia known as Barrett's oesophagus, the metaplasia probably being caused by prolonged reflux of gastric acid and digestive enzymes (reflux oesophagitis). With the passage of time the epithelial lining becomes progressively more abnormal as it passes through a series of sequential steps that eventually result in the development of invasive adenocarcinoma. These steps include the development of glandular dysplasia, signalled by an increased nuclear:cytoplasmic ratio and loss of nuclear polarity within the cells lining the metaplastic glands: …