The analysis of tumour remains fascinating. While e.g. viruses, methylation of DNA, gene silencing, mutations and deletions have been recognized for some time to play major roles in tumour development, a new player has emerged only recently: microRNA or miRNA. An Open Access review in Current Biology ( http://dx.doi.org/10.1016/j.cub.2014.06.043) features this new class of molecules and describes how they act on tumours. A must read!
The Breast Cancer Risk protein BRCA1 role is becoming analysed. While the mutation/deletion of this protein makes young women (males too) susceptible to develop breast tumours prematurely, how the protein did this was not clear for some time:
While Skully and collegues (doi: 10.1073/pnas.1400783111) claim a role in replication fork control, Palazzo et al. (doi: 10.4161/cc.27945) observe it is related to the mitotic spindel formation. Chiba and collegue (DOI: 10.1016/j.molcel.2013.10.028) show a complex pattern of BRCA1, its dimerisation partner BARD1 and the Obg-like ATPase 1, Ola-1 in the organisation of the centrosome.
Therefore, being involved in the basics of the machinery of cellular growth it is clear that BRCA1 once mutated makes the cell instable and prone to neoplastic transformation.