Genomic amplification of BCR/ABL1 and a region downstream of ABL1 in chronic myeloid leukaemia: a FISH mapping study of CML patients and cell lines

Table 3 Metaphase FISH screening in human CML cell lines

Cell line	Source	Cell type	Signal pattern with RP11-83J21(G) and RP11-323H21(R) probes		Location of 9q subtelomeric probe		Location of 22q subtelomeric probe
BV173	PB	B cell precursor	i.	2F: der(22)×2[20]	i.	der(22)×2	i.	22,der(9)
CML-T1¹	PB	T cell	i.	3F: 9,der(22)×2	i.	9,der(9)		NT
			ii.	6F: 9×2,der(22)×4	ii.	9×2,der(9)×2
			iii.	4F: der(22)×4	iii.	der(9)×2
EM-2	BM	Myeloid	i.	3F: der(22)×3[1]	i.	der(22)×3	i.	22,der(9)×2
			ii.	4F: der(22)×4[20]	ii.	der(22)×4
			iii.	5F: der(22)×5[21]	iii.	der(22)×5
JK-1	BST	Myeloid	i.	3F: 9,der(22)×2[23]	i.	9,der(22)×2	i.	22,der(9)
K562	PE	Myeloid	i.	+5F: marker×2, der(9)t(9;17), der(9)t(9;9)[20]	i.	der(9)t(9;17), der(9)t(9;9)	i.	22×2
KCL-22	PE	Myeloid	i.	3F: 9,der(22)×2[20]	i.	9,der(22)×2	i.	22,der(9)
KU812	PB	Myeloid early	i.	2F: der(22)×2[15]	i.	der(22)×2	i.	der(9)×2
		basophilic	ii.	+5F: der(22), marker[9]	ii.	der(22), marker
LAMA-84	PB	Granulocytic, megakaryocytic and erythroid	i.	4F: der(22)×4[20]	i.	der(22)×4	i.	22,der(9)×2
MC3²	PB	Myeloid, lymphoid and megakaryocytoid	i.	2G: der(22),der(22)* 2F: 9,der(22)* [19]	i. ii.	9,der(22)* 9,der(22)****	i. ii.	22,der(9) 22,der(9)
			ii.	2G: der(22)***
				2F: 9,der(22)**** [3]
MEG-01	BM	Megakaryoblastic	i.	3F: der(22), der(15)t(15;22)[36]	i.	der(7)t(7;22), der(15)t(15;22)	i.	der(9)×2

¹ CML-T1 is a Ph negative BCR/ABL1 positive cell line. The Ph chromosomes are indeed masked Ph chromosomes with an ins(22;9)(q11.2;q34.1q34.2). CML-T1 had 3 cell clones: one diploid and two tetraploid with/without a deletion of 9q34 on the "normal" 9.² MC3 had two Ph chromosomes with apparently classical morphology but FISH revealed the presence of two clones both with different Ph chromosome markers carrying cryptic duplications. Stars indicate the different derivative chromosomes 22. Clone i., der(22)* retained all 3' ABL1 → 9qter sequences and carried a duplication of both 9q telomere and a 438 Kb fragment from chromosome 9 (RP11-83J21 → RP11-544A12); der(22)** only retained a 682 Kb fragment from 9 (RP11-83J21 → RP11-643E14). Clone ii., der(22)*** only retained a 438 Kb region from 9 (RP11-83J21 → RP11-544A12) which was duplicated; der(22) **** retained all 3' ABL1 → 9qter sequences and carried a duplication of 9q telomere.

ISSN: 1755-8166