| 1. |
- Sjögren, Anna-Karin, 1980, et al.
(författare)
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GGTase-I deficiency reduces tumor formation and improves survival in mice with K-RAS-induced lung cancer
- 2007
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Ingår i: J Clin Invest. - 0021-9738. ; 117:5, s. 1294-304
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Tidskriftsartikel (refereegranskat)abstract
- Protein geranylgeranyltransferase type I (GGTase-I) is responsible for the posttranslational lipidation of CAAX proteins such as RHOA, RAC1, and cell division cycle 42 (CDC42). Inhibition of GGTase-I has been suggested as a strategy to treat cancer and a host of other diseases. Although several GGTase-I inhibitors (GGTIs) have been synthesized, they have very different properties, and the effects of GGTIs and GGTase-I deficiency are unclear. One concern is that inhibiting GGTase-I might lead to severe toxicity. In this study, we determined the effects of GGTase-I deficiency on cell viability and K-RAS-induced cancer development in mice. Inactivating the gene for the critical beta subunit of GGTase-I eliminated GGTase-I activity, disrupted the actin cytoskeleton, reduced cell migration, and blocked the proliferation of fibroblasts expressing oncogenic K-RAS. Moreover, the absence of GGTase-I activity reduced lung tumor formation, eliminated myeloproliferative phenotypes, and increased survival of mice in which expression of oncogenic K-RAS was switched on in lung cells and myeloid cells. Interestingly, several cell types remained viable in the absence of GGTase-I, and myelopoiesis appeared to function normally. These findings suggest that inhibiting GGTase-I may be a useful strategy to treat K-RAS-induced malignancies.
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| 2. |
- Wahlström, Annika, 1975, et al.
(författare)
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Inactivating Icmt ameliorates K-RAS-induced myeloproliferative disease.
- 2008
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Ingår i: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 112:4, s. 1357-65
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Tidskriftsartikel (refereegranskat)abstract
- Hyperactive signaling through the RAS proteins is involved in the pathogenesis of many forms of cancer. The RAS proteins and many other intracellular signaling proteins are either farnesylated or geranylgeranylated at a carboxyl-terminal cysteine. That isoprenylcysteine is then carboxyl methylated by isoprenylcysteine carboxyl methyltransferase (ICMT). We previously showed that inactivation of Icmt mislocalizes the RAS proteins away from the plasma membrane and blocks RAS transformation of mouse fibroblasts, suggesting that ICMT could be a therapeutic target. However, nothing is known about the impact of inhibiting ICMT on the development of malignancies in vivo. In the current study, we tested the hypothesis that inactivation of Icmt would inhibit the development or progression of a K-RAS-induced myeloproliferative disease in mice. We found that inactivating Icmt reduced splenomegaly, the number of immature myeloid cells in peripheral blood, and tissue infiltration by myeloid cells. Moreover, in the absence of Icmt, the ability of K-RAS-expressing hematopoietic cells to form colonies in methylcellulose without exogenous growth factors was reduced dramatically. Finally, inactivating Icmt reduced lung tumor development and myeloproliferation phenotypes in a mouse model of K-RAS-induced cancer. We conclude that inactivation of Icmt ameliorates phenotypes of K-RAS-induced malignancies in vivo.
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