M. Speletas et al., Rapid mutational analysis of N-ras proto-oncogene in hematologic malignancies: a study of 77 Greek patients, HAEMATOLOG, 86(9), 2001, pp. 918-927
Background and Objectives. N-ras mutations are the most commonly detected m
olecular abnormalities in hematologic malignancies, especially in those of
myeloid origin. Different techniques have been used to detect N-ras mutatio
ns; however, most of them are either labor intensive or provide sequence da
ta for only a limited number of codons. Consequently, study of the N-ras on
cogene has not been convenient in every day clinical practice being restric
ted, as a rule, to retrospective analysis of patients.
Design and Methods. In this study we used a recently developed method that
enables rapid and reliable detection of mutations at the cDNA level; namely
, the non-isotopic RNase cleavage assay (NIRCA). Using this method we were
able to screen the N-ras oncogene rapidly and determine the incidence and p
rognostic significance of N-ras mutations in 77 Greek patients with acute l
eukemia; myelodysplastic syndromes and chronic myeloproliferative disorders
, both. at presentation and during relapse or progression of the disease.
Results. Activating N-ras mutations were detected in 7 patients and our res
ults were confirmed by direct sequencing. Interestingly, two novel alterati
ons were identified, a mutation at codon 8 (characterized by a substitution
of valine by leucine) in a patient with chronic myeloid leukemia during he
matologic relapse of the disease and a polymorphism at codon 92 (1002T -->C
, without amino acid substitution) in a patient with chronic myelomonocytic
leukemia.
Interpretation and Conclusions. A rapid and easy protocol that allows the a
nalysis of N-ras sequences has been developed. This reverse transcription-p
olymerase chain reaction (RT-PCR)/NIRCA protocol can allow the study of thi
s proto-oncogene in every day clinical practice; rapidly facilitating the v
alidation of the diagnostic and prognostic value of N-ras mutational analys
es in patients with hematologic malignancies. (C) 2001, Ferrata Storti Foun
dation.