title: Involvement of KRAS G12A mutation in the IL-2-independent growth of a human T-LGL leukemia cell line, PLT-2.
abstract: Cytokine-dependent cell lines have been used to analyze the cytokine-induced cellular signaling and the mechanism of oncogenesis. In the current study, we analyzed MOTN-1 and PLT-2 cell lines established from different stages of a T-cell large granular lymphocyte leukemia patient (Daibata et al. 2004). MOTN-1 is IL-2-dependent derived from the chronic phase, whereas IL-2-independent PLT-2 is from the aggressive and terminal stage. They shared considerable chromosome abnormalities and the pattern of T-cell receptor rearrangement, presuming that the cytokine independence of PLT-2 was due to the additive genetic abnormality. Besides IL-2, IL-15 supported MOTN-1 cell growth, because these receptors share beta- and gamma-subunits. IL-2 activated ERK, AKT and STAT pathway of MOTN-1. STAT3 pathway of PLT-2 was also activated by IL-2, suggesting intact IL-2 induces signal transduction of PLT-2. However, ERK1/2 but not AKT, was continuously activated in PLT-2, consistent with the increased Ras-activity of PLT-2. Sequence analysis revealed KRAS G12A mutation but not NRAS and HRAS mutation of PLT-2 but not MOTN-1. Another signaling molecule affecting Ras-signaling pathway, SHP2, which has been frequently mutated in juvenile myelomonocytic leukemia (JMML), did not show mutation. Moreover, MEK inhibitor, PD98059, as well as farnesylation inhibitor inhibited PLT-2 cell growth. Using NIH3T3 and MOTN-1, ERK activation, increased cell proliferation and survival by KRAS G12A were shown, suggesting the important role of KRAS G12A in IL-2-independent growth of PLT-2. Taken together, KRAS G12A is important for IL-2-independent growth of PLT-2 cells and suggests the possibility of involvement of KRAS mutation with disease progression.
authors.affiliation: Division of Pathophysiological Laboratory Sciences, Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Mizutani
authors.forename: Hiromi
authors.initials: H
authors.lastname: Ito
authors.forename: Kazumi
authors.initials: K
authors.lastname: Hagiwara
authors.forename: Misa
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Asuka
authors.initials: A
authors.lastname: Hoshikawa
authors.forename: Yayoi
authors.initials: Y
authors.lastname: Nishida
authors.forename: Akira
authors.initials: A
authors.lastname: Takagi
authors.forename: Tetsuhito
authors.initials: T
authors.lastname: Kojima
authors.forename: Motoshi
authors.initials: M
authors.lastname: Suzuki
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Osawa
authors.forename: Kazunori
authors.initials: K
authors.lastname: Ohnishi
authors.forename: Masanori
authors.initials: M
authors.lastname: Daibata
authors.forename: Takashi
authors.initials: T
authors.lastname: Murate
mesh_terms: D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D005419:Flavonoids / Q000494:pharmacology; D006801:Humans; D019409:Interleukin-15 / Q000494:pharmacology; D007376:Interleukin-2 / Q000494:pharmacology*; D054066:Leukemia, Large Granular Lymphocytic / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics / Q000378:metabolism; D018631:ras Proteins / Q000235:genetics*
chemical_list: D005419:Flavonoids; D019409:Interleukin-15; D007376:Interleukin-2; C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one