Title

The nonhomologous end joining factor Artemis suppresses multi-tissue tumor formation and prevents loss of heterozygosity.

Document Type

Article

Publication Date

2007

Keywords

DNA-Repair, Genes-p53, Humans, Loss-of-Heterozygosity, Lymphoma, Mice-Knockout, Neoplasms, Nuclear-Proteins, Sarcoma-Experimental, Severe-Combined-Immunodeficiency, Tumor-Suppressor-Protein-p53

JAX Source

Oncogene 2007 Sep; 26(41):6010-20.

Abstract

Nonhomologous end joining (NHEJ) is a critical DNA repair pathway, with proposed tumor suppression functions in many tissues. Mutations in the NHEJ factor ARTEMIS cause radiation-sensitive severe combined immunodeficiency in humans and may increase susceptibility to lymphoma in some settings. We now report that deficiency for Artemis (encoded by Dclre1c/Art in mouse) accelerates tumorigenesis in several tissues in a Trp53 heterozygous setting, revealing tumor suppression roles for NHEJ in lymphoid and non-lymphoid cells. We also show that B-lineage lymphomas in these mice undergo loss of Trp53 heterozygosity by allele replacement, but arise by mechanisms distinct from those in Art Trp53 double null mice. These findings demonstrate a general tumor suppression function for NHEJ, and reveal that interplay between NHEJ and Trp53 loss of heterozygosity influences the sequence of multi-hit oncogenesis. We present a model where p53 status at the time of tumor initiation is a key determinant of subsequent oncogenic mechanisms. Because Art deficient mice represent a model for radiation-sensitive severe combined immunodeficiency, our findings suggest that these patients may be at risk for both lymphoid and non-lymphoid cancers.