Background: Germ cell (GC) tumours are uniquely associated with the gametogenic tissues of males and females. A feature of these cancers is that they can express genes that are normally tightly restricted to meiotic cells. This aberrant gene expression has been used as an indicator that these cancer cells are attempting a programmed germline event, meiotic entry. However, work in non-germ cell cancers has also indicated that meiotic genes can become aberrantly activated in a wide range of cancer types, and indeed provide functions that serve as oncogenic drivers. Here we review the activation of meiotic factors in cancers, and explore commonalities between meiotic gene activation in GC and non-GC cancers.
Objectives: The objectives of this review are to highlight key questions relating to meiotic gene activation in GC tumours and to offer possible interpretations as to the biological relevance in this unique cancer type.
Materials and Methods: Pubmed and the GEPIA database were searched for papers in English and for cancer gene expression data respectively.
Results: We provide a brief overview of meiotic progression, with a focus on the unique mechanisms of reductional chromosome segregation in meiosis I. We then offer detailed insight into the role of meiotic chromosome regulators in non-GC cancers and extend this to provide an overview of how this might relate to GC tumours.
Conclusions: We propose that meiotic gene activation in GC tumours might not indicate an unscheduled attempt to enter a full meiotic program. Rather, it might simply reflect either aberrant activation of a sub-set of meiotic genes, with little or no biological relevance, or aberrant activation of a sub-set of meiotic genes as positive tumour evolutionary/oncogenic drivers. These postulates provide the provocation for further studies in this emerging field.