Alterations of p53 and Rb genes in a novel human GM‐CSF‐dependent myeloid cell line (OHN‐GM) established from therapy‐related leukaemia

Abstract

Summary.A novel GM-CSF-dependent myeloid cell line, OHN-GM, was established from a patient who developed acute myelogenous leukaemia (AML) as a consequence of myelodysplastic syndrome (MDS). As the patient had previously received cytotoxic chemotherapy for Hodgkin's disease, the MDS and AML were probably related to such therapy. Sequential karyotypic analysis established a del(5q) as the initial cytogenetic abnormality. Additional alterations, including t(10;13)(q24;q14), had developed subsequently during disease progression. Southern blot analysis of OHN-GM cells suggested deletion of one allele of the IRF-1 gene, although no aberrant transcripts were detected. Fluorescence in situ hybridization analysis revealed the deletion of the Rb gene due to the t(10;13)(q24;q14) translocation, and Western blot analysis demonstrated the absence of Rb protein in OHN-GM cells. Finally, the OHN-GM cells exhibited two missense point mutations in highly conserved regions of the p53 gene. These observations suggest that a multistep process, involving alterations of Rb and p53 genes, may have contributed to the patient's disease development and progression. To our knowledge, OHN-GM is the first cell line derived from a therapy-related AML. These cells may aid the investigation of leukaemogenesis as well as the biology of secondary leukaemia.

Combined spectral karyotyping and DAPI banding analysis of chromosome abnormalities in myelodysplastic syndrome

“…Nineteen patients with MDS and a cell line (OHN-GM) established from a case of therapyrelated leukemia following transformation of MDS were the subjects of the present study (Nagai et al, 1997). The diagnosis of MDS and its subtyping were performed according to the criteria proposed by the FAB group (Bennett et al, 1982(Bennett et al, , 1985.…”

The cell growth, morphology and immunocytochemistry of novel cell line established from a bone marrow of the patient with therapy-related myelodysplastic syndrome, entitled PC-MDS

“…To date, only OHN-GM cell line was derived from the patient with therapy-related MDS/AML [9]. However, the OHN-GM cell line was established from the bone marrow cells Population density level was calculated by formula: PDL=log 10(N/ N 0 ) · 3.33, here N represents cell number at the end of culture and N 0 represents initial cell number Fig.…”

“…Drexler [1] recently reported on 10 cell lines derived from the various MDS subtypes and 17 cell lines from the patients with post-MDS leukemia. Among MDS subtypes-derived cell lines only one cell line was derived from the patient with therapy-related MDS/AML (t-MDS/ t-AML) [9].…”

True

“…In total, 14 out of the 17 patients with myeloid malignancies (82.4%) exhibited allelic loss at either locus of the RB gene, D13S319, and D13S25, or loss of the RB gene only. On the other hand, only three CLL patients (patients 18-20) (25.0%) exhibited allelic loss in these loci among 12 patients with lymphoid malignancies exhibiting deletion (patients [18][19][20][21][22] or translocation (patients [23][24][25][26][27][28][29] (Figure 1, Table 1b). Of the three, two exhibited allelic loss at both the RB gene and the D13S319 loci and one in all loci of the RB gene, D13S319 and D13S25.…”

“…Sixteen patients with myeloid disorders, one AML cell line (OHN-GM) 22 and 12 patients with lymphoid disorders who had chromosome aberrations at band 13q14 were investigated in the present study. Clinical diagnoses and the karyotypes are shown in Table 1a and b. Forty-four AML patients who did not have deletion of 13q or monosomy 13 at diagnosis also underwent FISH analysis in the RB gene as a control study.…”