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ROSAKIT WT
2011
2014
PB of a patient with allergic disease
Normal CB-derived CD34+ cells
Short (48-72 h)
Short (48-72 h)
KIT WT
KIT WT
No
Yes
Yes
Preclinical models of mastocytosis
Tables 1-4), although, in contrast to ROSAKIT WT cells, repeated attempts to activate ROSAKIT D816V cells by cross- linking FcεRI failed in our hands.15 Interestingly, KIT (CD117) is expressed at higher levels in ROSAKIT D816V cells than in ROSAKIT WTcells.15 While KIT phosphorylation in ROSAKIT WT cells needs the presence of SCF, KIT is consti- tutively phosphorylated in ROSAKIT D816V cells.15 In addi- tion, STAT5 and AKT are constitutively phosphorylated in ROSAKIT D816V cells, as in primary neoplastic MC.22,24,39 Interestingly, inhibition of AKT or STAT5 decreases ROSAKIT D816V cell proliferation.15 As expected, ROSAKIT WT cells responded to imatinib, while ROSAKIT D816V cells were resistant to imatinib, but sensitive to dasatinib or midostaurin (PKC412),15 making these couple of cell lines a convenient tool for determining the relative selectivity of TKI towards the two forms of KIT (WT versus D816V).
Table 1. Major characteristics of the available human mast cell lines.
Of note, ROSAKIT D816V cells were reported to engraft NOD/SCID IL-2Rγ−/− (NSG) mice efficiently, giving rise to an ASM/MCL-like disease in vivo,15 described later in this manuscript. Thus, the ROSAKIT D816V cell line is a unique model of human KIT D816V+ ASM/MCL useful for in vitro and in vivo studies.
Finally, ROSA cells also appear well suited to investi- gating the transforming potential of KIT mutants found in other categories of mastocytosis. For example, starting from ROSAKIT WT, we created ROSA subclones stably expressing the mutant KIT Del417-419insY (NM_000222.2(KIT):c.1249_1255delinsT, p.Thr417_Asp419delinsTyr), or the mutant KIT K509I (NM_000222.2(KIT):c.1526A>T, p.Lys509Ile), both found in pediatric patients.20 In each case, the cells became SCF-independent, and KIT was found constitu-
Cell line
HMC-1
Subclones HMC-1.1 HMC-1.2
Date of first description
1988
Origin
PB of a patient with MCL
Doubling time
Short (48-72 h)
KIT
status
SCF- dependence
FcεRI expression
Authentication by DNA fingerprinting
Karyotype
Presence of non-KIT somatic mutation(s)
u.k.
KIT V560G
and (46<2n>XX,
KIT D816V
ins(10;16) (q25;q22q12), add(13)(q33))
No
No
No
No
Complex
LAD subclones (1-5)*
LUVA
2003
2003
BM cells of a patient with KIT D816G+ MCL
Long (2 weeks)
KIT V560G
KIT V560G and KIT D816V
KIT WT
Yes
Yes
Yes
Complex (41-72,XXY, -[7],+2[11], +4[2],+5[6],+7[2], +16[3], +18[2], -21[14] cp15)§
u.k.
u.k.
u.k.
MCPV-1 subclones (1.1-1.4)
BM: bone marrow; CB: cord blood; MC: mast cell; MCL: mast cell leukemia; PB: peripheral blood; SCF: stem cell factor; u.k.: unknown. *Only the LAD2 subclone has been widely distributed since its description. §Karyotype of the LAD2 subclone.
SF3B1 K700E
ROSAKIT D816V
2014
ROSAKITWT cells transduced with a KIT D816V construct
Normal CB-derived MC progenitors transduced with HRAS G12V
haematologica | 2018; 103(11)
Short (48-72 h)
KIT D816V
KIT WT
No
No
Yes
No
No
No
Complex (see description in the text)
u.k.
HRAS G12V
1763