Background and objectiveMaintenance of genomic integrity is essential to ensure normal organismal development and to prevent diseases such as cancer. PR-Set7 (also known as Set8) is a cell cycle regulated enzyme that catalyses monomethylation of histone 4 at Lys20 (H4K20me1) to promote chromosome condensation and prevent DNA damage. Recent studies show that CRL4CDT2-mediated ubiquitylation of PR-Set7 leads to its degradation during S phase and atfer DNA damage. hTis might occur to ensure appropriate changes in chromosome structure during the cell cycle or to preserve genome integrity atfer DNA damage.Methods We developed a new model of lung tumor development in mice harboring a conditionally expressed allele of Cul4A. We have therefore used a mouse model to demonstrate for the ifrst time that Cul4A is oncogenicin vivo. With this model, staining of PR-Set7 in the preneoplastic and tumor lesions in AdenoCre-induced mouse lungs was performed. Meanwhile we identiifed higher protein level changes of γ-tubulin and pericentrin by IHC.Results hTe level of PR-Set7 down-regulated in the preneoplastic and adenocarcinomous lesions following over-expression of Cul4A. We also identiifed higher levels of the proteins pericentrin and γ-tubulin in Cul4A mouse lungs induced by AdenoCre.Conclusion PR-Set7 is a direct target of Cul4A for degradation and involved in the formation of lung tumors in the conditional Cul4A transgenic mouse model.

Lung cancer is the leading cause of cancer-related deaths worldwide. Recently, advancements in our ability to identify and study stem cell populations in the lung have helped researchers to elucidate the central role that cells with stem cell-like properties may have in lung tumorigenesis. Much of this research has focused on the use of the airway repair model to study response to injury. In this review, we discuss the primary evidence of the role that cancer stem cells play in lung cancer development. The implications of a stem cell origin of lung cancer are reviewed, and the importance of ongoing research to identify novel therapeutic and prognostic targets is reiterated.
Animals ; Carcinoma, Non-Small-Cell Lung ; pathology ; Cell Transformation, Neoplastic ; Humans ; Lung Injury ; physiopathology ; Lung Neoplasms ; pathology ; Neoplastic Stem Cells ; pathology ; Regeneration