Retroviral expression screening of oncogenes in natural killer cell leukemia

Received 17 October 2004; accepted 22 January 2005.

Abstract

Aggressive natural killer cell leukemia (ANKL) is an intractable malignancy that is characterized by the outgrowth of NK cells. To identify transforming genes in ANKL, we constructed a retroviral cDNA expression library from an ANKL cell line KHYG-1. Infection of 3T3 cells with recombinant retroviruses yielded 33 transformed foci. Nucleotide sequencing of the DNA inserts recovered from these foci revealed that 31 of them encoded KRAS2 with a glycine-to-alanine mutation at codon 12. Mutation-specific PCR analysis indicated that the KRAS mutation was present only in KHYG-1 cells, not in another ANKL cell line or in clinical specimens (n=8).

Keywords: Aggressive NK cell leukemia, cDNA expression library, Retrovirus, KRAS2 oncogene

a Division of Functional Genomics, Jichi Medical School, 3311-1 Yakushiji, Kawachigun, Tochigi 329-0498, Japan

b Division of Hematology, Department of Medicine, Juntendo University School of Medicine, Tokyo, Japan

c Department of Molecular Microbiology and Immunology, Nagasaki University Graduate School of Medicine, Nagasaki, Japan

d Center for Experimental Medicine, Institute of Medical Science, University of Tokyo, Tokyo, Japan

e Second Department of Internal Medicine, Shinshu University School of Medicine, Nagano, Japan

f CREST, Japan Science and Technology Agency, Saitama, Japan

Corresponding author. Tel.: +81 285 58 7449; fax: +81 285 44 7322.

PII: S0145-2126(05)00058-5

doi:10.1016/j.leukres.2005.02.002

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