Oncogenic NRAS, KRAS, and HRAS Exhibit Different Leukemogenic Potentials in Mice

Abstract

RAS proteins are small GTPases that play a central role in transducing signals that regulate cell proliferation, survival, and differentiation. The RAS proteins interact with a common set of activators and effectors; however, they associate with different microdomains of the plasma membrane as well as other endomembranes and are capable of generating distinct signal outputs. Mutations that result in constitutive activation of RAS proteins are associated with f30% of all human cancers; however, different RAS oncogenes are preferentially associated with different types of human cancer. In myeloid malignancies, NRAS mutations are more frequent than KRAS mutations, whereas HRAS mutations are rare. The mechanism underlying the different frequencies of RAS isoforms mutated in myeloid leukemia is not known. In this study, we compared the leukemogenic potential of activated NRAS, KRAS, and HRAS in the same bone marrow transduction/transplantation model system. We found that all three RAS oncogenes have the ability to induce myeloid leukemias, yet have distinct leukemogenic strengths and phenotypes. The models established here provide a system for further studying the molecular mechanisms in the pathogenesis of myeloid malignancies and for testing targeted therapies. [Cancer Res 2007;67(15):7139-46]

Let-7a regulates mammosphere formation capacity through Ras/NF-κB and Ras/MAPK/ERK pathway in breast cancer stem cells

“…The transduction was performed as described previously. 24,51,52 The expression of let-7a and KRas were detected by qRT-PCR and Western blot analysis as described below.…”

Role of a non-canonical splice variant of the Helios gene in the differentiation of acute lymphoblastic leukemic T cells

“…of Helios-deregulated T-ALL (20). In addition, we observed that ectopic expression of Helios-Δ326-1431 led to the upregulated expression of HRAS, which exhibited leukemogenic potential in myeloid-lineage leukemia (21). Furthermore, this study identified that other components of the RAS signaling pathway, such as RASSF7, RAB40B, and RASIP1, were upregulated in the Helios-Δ326-1431 overexpressed cells.…”

N-Arachidonoyl Dopamine Inhibits NRAS Neoplastic Transformation by Suppressing Its Plasma Membrane Translocation

“…Retroviral constructs expressing NRAS-G12D, KRAS4A-G12D, KRAS4B-G12D, and NRAS-G12D-C181S as N-terminal GFP-fusion proteins were generated as previously described (19,22). The retroviruses were produced using Bosc23 cells and were titered as previously described (22).…”

“…The growth factor dependent Ba/F3 cells were cultured in RPMI 1640 (Gibco), including 10% fetal bovine serum (FBS, Gibco), and supplemented with 15% WEHI-3-conditioned medium as a source of IL3 or with recombinant IL3 (Roche) at the final concentration of 1 ng/mL. The Ba/F3 and NIH3T3 cells were transduced with retroviruses as described (22,24). The HeLa cell line was bought from ATCC in 2009 and cultured according to the instruction.…”

“…Western blot analyses were performed as previously described (22). Primary antibodies used were: anti-RAS, anti-phospho ERK1/2, anti-ERK1/2, anti-phospho MEK, anti-MEK (Cell Signaling Technology); anti-NRAS, anti-KRAS4B (Santa Cruz Biotechnology); anti-b-Actin (Sigma Aldrich) and HRP-linked streptavidin (Sigma Aldrich); secondary antibodies were: Anti-mouse and anti-rabbit IgG secondary antibodies (Cell Signaling Technology).…”