Z Gastroenterol 2007; 45 - A_60
DOI: 10.1055/s-2007-992748

Expression and Prognostic Value of Minichromosome Maintenance Proteins MCM2, MCM7 and Geminin in Colorectal Cancer

W Müller 1, H Grabsch 2, J Knock 2, HE Gabbert 3
  • 1Gemeinschaftspraxis Pathologie Starnberg
  • 2Pathology & Tumour Biology, Leeds Institute of Molecular Medicine, University of Leeds, UK
  • 3Institut für Pathologie, Heinrich-Heine-Universität Düsseldorf

Objectives:

Minichromosome maintenance (MCM) proteins and Geminin are essential for eukaryotic DNA replication. Dysregulation of MCM protein expression has been shown in different human malignancies. However, the expression pattern of MCM and Geminin has not been investigated in detail in colorectal cancer (CRC).

Material and Methods:

Expression of MCM2, MCM7 and Geminin was investigated by immunohistochemistry in 342 CRC and compared with clinicopathological data and patient survival.

Results:

Nuclear expression of MCM2, MCM7 and Geminin was observed in all CRC ranging from 1 to 99% positively stained tumour cells/case (mean: 69%, 58% and 20%). High expression of all three proteins was associated with high expression of Ki67 (p<0,001). High Geminin expression was more common in poorly differentiated CRC. Low MCM2 and MCM7 expression was more common in CRC with high pT. Multivariate analysis adjusting the model for pT, pN and grade showed that high expression of MCM2 was associated with longer overall survival, whereas high expression of MCM7 was associated with both, overall and disease free survival.

Conclusions:

In contrast to the published results from other tumour entities, our study in 342 CRC showed that high MCM2 and MCM7 expression is associated with longer survival. This could suggest that the regulation of DNA replication initiation differs between CRC and other cancer types and warrants further studies into the expression of the other MCM proteins and their regulating proteins.