| 1. |
- Anderson, Kristina, et al.
(author)
-
Fluorescence in situ hybridization for the study of cell lineage involvement in myelodysplastic syndromes with chromosome 5 anomalies
- 2002
-
In: Cancer Genetics and Cytogenetics. - 0165-4608. ; 136:2, s. 101-107
-
Journal article (peer-reviewed)abstract
- Fluorescence in situ hybridization (FISH) with a locus-specific dual DNA probe (LSI EGR-1SO/D5S23SG) for chromosome 5 was used in combination with morphology to study bone marrow cell lineage involvement of the abnormal chromosomal clone in 13 patients with deletion 5q[del(5q)], either as a sole aberration or as part of a complex karyotype, and in six cases with monosomy 5 by metaphase cytogenetics, all with complex karyotypes including 2-6 marker chromosomes. In the monosomy 5 group, only one case displayed the expected one orange and one green (1O + 1G) FISH pattern in a majority of the cells. The other five patients instead showed 1O + 2G FISH signals in 17-86% of the bone marrow cells, which is the typical pattern for del(5q). In the del(5q) group, 26-98% of the bone marrow cells exhibited 10 + 2G FISH signals. All patients showed clonal involvement of the myeloid cell lineages, including the megakaryocytes in a few cases, whereas lymphoid cells generally exhibited the normal 20 + 2G FISH pattern. No difference was seen between patients with 5q- syndrome, those with del(5q) and a complex karyotype, and the monosomy 5 group. We were thus unable to confirm the recent suggestion that B-cells are a part of the abnormal clone in MDS with del(5q). Furthermore, true monosomy 5 seems to be rare in MDS. (C) 2002 Elsevier Science Inc. All rights reserved.
|
|
| 2. |
- Nilsson, Lars, et al.
(author)
-
Involvement and functional impairment of the CD34(+)CD38(-)Thy-1(+) hematopoietic stem cell pool in myelodysplastic syndromes with trisomy 8.
- 2002
-
In: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 100:1, s. 259-267
-
Journal article (peer-reviewed)abstract
- Clonality studies of mature cells suggest that the primary transformation event in myelodysplastic syndrome (MDS) most frequently occurs in a myeloid-restricted progenitor, a hypothesis supported by recent studies of purified CD34(+)Thy1(+) hematopoietic stem cells (HSCs) in cases with trisomy 8 (+8). In contrast, we recently demonstrated that a lymphomyeloid HSC is the target for transformation in MDS cases with del(5q), potentially reflecting heterogeneity within MDS. However, since +8 is known to frequently be a late event in the MDS transformation process, it remained a possibility that CD34(+)CD38(-)Thy1(+) HSC disomic for chromosome 8 might be part of the MDS clone. In the present studies, although a variable fraction of CD34(+)CD38(-)Thy1(+) cells were disomic for chromosome 8, they did not possess normal HSC activity in long-term cultures and nonobese diabetic-severe combined immunodeficiency (NOD-SCID) mice. Mixing experiments with normal CD34(+)CD38(-) cells suggested that this HSC deficiency was intrinsic and not mediated by indirect mechanisms. Furthermore, investigation of 4 MDS cases with combined del(5q) and +8 demonstrated that the +8 aberration was always secondary to del(5q). Whereas del(5q) invariably occurs in CD34(+)CD38(-)Thy-1(+) HSCs, the secondary +8 event might frequently arise in progeny of MDS HSCs. Thus, CD34(+)CD38(-)Thy1(+) HSCs are invariably part of the MDS clone also in +8 patients, and little HSC activity can be recovered from the CD34(+) CD38(-)Thy1(+) HSC. Finally, in advanced cases of MDS, the MDS reconstituting activity is exclusively derived from the minor CD34(+)CD38(-) HSC population, demonstrating that MDS stem cells have a similar phenotype as normal HSCs, potentially complicating the development of autologous transplantation for MDS.
|
|
| 3. |
|
|
