MCM proteins as diagnostic and prognostic tumor markers in the clinical setting

Minichromosome maintenance (MCM) proteins are essential for the process of DNA replication, functioning as license components for the S-phase of cell-cycle initiation and further exerting weak helicase activity to unwind DNA from its supercoiled state at replication forks. The requirement for MCM proteins in cycling cells and their absence in quiescent ones supports evidence for their potential clinical application as cell proliferation markers. In the last few years, aside from their utility as cell proliferation markers, the assessment of MCM expression levels in diverse human malignancies has been the focus of extensive research in an aim to facilitate tumor diagnosis and prognosis in clinical settings. The present article aims to review the available data so far concerning the clinical significance of MCM protein expression in human neoplasia in comparison to conventional proliferative markers. A review of the literature revealed that MCM expression is associated with important clinicopathological parameters for patient management and also exhibits significant diagnostic and prognostic value in several malignancies. MCMs are characterized by higher specificity and sensitivity than the conventional proliferative markers, such as Ki-67 and PCNA, and are thus considered as diagnostic and prognostic tools of greater clinical significance in several types of human malignancy.