First Author | Engelmann A | Year | 2008 |
Journal | Oncogene | Volume | 27 |
Issue | 10 | Pages | 1429-38 |
PubMed ID | 17891184 | Mgi Jnum | J:132102 |
Mgi Id | MGI:3775137 | Doi | 10.1038/sj.onc.1210772 |
Citation | Engelmann A, et al. (2008) Gadd45beta is a pro-survival factor associated with stress-resistant tumors. Oncogene 27(10):1429-38 |
abstractText | Tumors that acquire resistance against death stimuli constitute a severe problem in the context of cancer therapy. To determine genetic alterations that favor the development of stress-resistant tumors in vivo, we took advantage of polyclonal tumors generated after retroviral infection of newborn Elambda-MYC mice, in which the retroviral integration acts as a mutagen to enhance tumor progression. Tumor cells were cultivated ex vivo and exposed to gamma-irradiation prior to their transplantation into syngenic recipients, thereby providing a strong selective pressure for pro-survival mutations. Secondary tumors developing from stress-resistant tumor stem cells were analysed for retroviral integration sites to reveal candidate genes whose dysregulation confer survival. In addition to the gene encoding the antiapoptotic Bcl-x(L) protein, we identified the gadd45b locus to be a novel common integration site in these tumors, leading to enhanced expression. In accord with a thus far undocumented role of Gadd45beta in tumorigenesis, we showed that NIH3T3 cells overexpressing Gadd45beta form tumors in NOD/SCID mice. Interestingly and differently to other known 'classical' antiapoptotic factors, high Gadd45beta levels did not protect against MYC-, UV- or gamma-irradiation-induced apoptosis, but conferred a strong and specific survival advantage to serum withdrawal. |