Solo 96 TKs in tutto il genoma umano!. Nucleus GRB2 GAB2 SOS RAS GDP SHC RAS GTP ERK JUN.
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Solo 96 TKs in tutto il genoma umano!
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Transcript of Solo 96 TKs in tutto il genoma umano!. Nucleus GRB2 GAB2 SOS RAS GDP SHC RAS GTP ERK JUN.
Solo 96 TKs in tutto il genoma umano!
Nucleus
GRB2GAB2
SOS
RAS GDP
SHC
RAS GTP
ERK
JUN
GRB2GAB2
SHC
PI3K
mTOR
Apoptosis block
Perché esiste una specificità di risposta se tutti i segnali attivano le stesse vie?
Perché gli stessi segnali possono attivare risposte diverse?
NUCLEUS
Cell Cycle
ABL
ABL is a “shuttle” TK
Radiatons->genetic damage
Rb, p53,p73
Block in G1
ABL
Scaffold protein
Intensità del segnale Durata del segnale Possibilità di spegnerlo più o meno
rapidamente
Meccanismi di attivazione
Riarrangiamenti Amplificazioni Mutazioni puntiformi ……….
Riarrangiamenti
Spesso conseguenza di traslocazioni cromosomiche (BCR-ABL, NPM-ALK) o di delezioni intracromosomiche (FIP1-PDGFRa)
Meccanismo più frequente nelle neoplasie ematologiche che nei tumori solidi
ABL ABL
Tyr Tyr
BCR BCR
Autophosphorylation by dimerization
P
Phosphorylation of substrates
Amplificazioni
Più frequenti nei tumori solidi che nei tumori ematologici (ERB2 nel Ca mammario etc…)
Più frequente per recettori di membrana Meccanismo di attivazione: l’aumento delle
molecole in superficie ne favorisce il contatto anche in assenza di ligando
Mutazioni puntiformi Numerosi esempi sia nei tumori
ematologici (JAK2 in DMPC-Ph-negativi) che nei tumori solidi (KIT nei GIST)
Meccanismo di attivazione: meccanismo di attivazione diretto del dominio TK
amino acid
substitutions
PP P
P
P
P
P
P
P
P
***
JAKRAS
P
P
P
P
FLT3 activation in AML (30% of cases)
P
P
P
P
ITD
STAT
D835Y
NUCLEUS
Cell Cycle
ABL
ABL is a “shuttle” TK
Radiatons->genetic damage
Rb, p53,p73
Block in G1
Deacreased DNA repair= genomic instabilityJane Wang, Paolo Vigneri et al.
BCR/ABL ABL
Bcr-Abl
ImatinibMechanism of action
ProteinaTir
PPATP
P
STI
ATP bindingpocket
ImatinibImatinib Response and Disease Phase Response and Disease Phase
Chronic phase
IFN failure
(n=532)
Accelerated
phase
(n=235)
Myeloid
Blast crisis
(n=229)
Haematological response 95% 83% 31%
Complete 95% 54% 8%No evidence of leukaemia - 12% 4%Return to CP - 17% 18%
Major cytogenetic response 60% 26% 15%
Complete 41% 18% 7%
Partial 19% 8% 8%
Ph+
Ph+Ph+
Ph+Ph+
Ph+Ph+
Ph+
Ph+ Ph+Ph+ Ph+ Ph+ Ph+ Ph+ Ph+ Ph+ Ph+
Ph+
Ph+
Ph+
Ph+Ph+
Ph+
Ph+
Ph1
Ph1
Ph1
Ph1Ph1
Ph1Ph1
Ph1Ph1 Ph1
Ph1Ph1
Ph1
Ph1Ph1
Ph+
Ph+
Ph+
Ph+
Ph+
Ph+
Ph+Ph+
Ph+
Ph+
Ph+
Ph+
Ph+
Ph+Ph+
Ph+Ph+
Ph+Ph+
NN
NN
N
N
N
N
N
N
N
NN
N
N
N
NN
Ph+
N
N
N
NN
N
N
N N N
NN
NN
N
N
NN
N
N
N
N
N
NN
NN
N
NN
NN
N
N
N
NN
N
N
N
N
N
N
N
N
N
N
N
N
N
NN
Ph+
Ph+
Ph+
Ph+
Ph+
Ph1
Ph1
Studio 102 – OVERALL SURVIVAL
% o
f pa
tie
nts
ali
ve
Median survivalUntreated patients 7.5 monthsPretreated patients 5.6 monthsSince diagnosis of blast crisis 9.9 months
p=0.16
3 6 9 12 15 18 21 24 27 30 33 36
Months since start of treatment
00
10
20
30
40
50
60
70
80
90
100
0
10
20
30
40
50
60
70
80
90
100
STUDIO 106 – OVERALL SURVIVALAll deaths
ImatinibIFN + Ara-C
% a
live
Months since randomization
0 3 6 9 12 15 18 21 24
ImatinibIFN + Ara-C
Imatinib IFN + Ara-CCML related deaths 9 16Deaths after BMT 3 5Other deaths 8 7Estimated survival at 18 months (p=0.16) 97.2% 95.1%
CHRMCyRCCyR
% r
espo
ndin
g
0
10
20
30
40
50
60
70
80
90
100
Months since randomization to Imatinib0 6 12 18 24 30 36 42 48 54 60 66
Cumulative Best Response at 12 and 60 months on First-line Imatinib in IRIS study
96%
85%
69%
98%92%87%
96%
85%
69%
98%92%
Survival without AP/BC
Event-free Survival
% w
ithou
t eve
nt
0
10
20
30
40
50
60
70
80
90
100
Months since randomization0 6 12 18 24 30 36 42 48 54 60 66
Event-free Survival and Survival Without AP/BC on First-line Imatinib
Actual Events6.3% AP/BC (n=35)5.1% loss of MCyR (n=28)2.5% loss of CHR (n=14)1.6% CML-unrelated deaths (n=9)
83%
(90-96)
(80-87)
Estimated rate at 60 months (with 95%CI)
93%
98%
84%
Annual Event Rateson First-line Imatinib
Year All events* AP/BC
1st 3.3% 1.5%
2nd 7.5% 2.8%
3rd 4.8% 1.6%
4th 1.5% 0.9%
5th 0.9% 0.6%
* All deaths or loss of response including progression to AP/BC
Survival Without AP/BC by Molecular Response at 12 months on First-line Imatinib
n=136 100%n= 94 95%n=138 88%
Estimated rate at 60 months
p<0.001 p=0.007
Response at 12 months
CCyR with >=3 log red.CCyR with <3 log red.No CCyR
% w
ithou
t AP
/BC
0
10
20
30
40
50
60
70
80
90
100
Months since randomization
0 6 12 18 24 30 36 42 48 54 60 66
Druker et al., ASCO 2006
PhRPhR
PhR PhR
PhR
Imatinib ImatinibPh+
Ph+Ph+ Ph+
Ph+Ph+
Ph+
Ph+
Ph+
Ph+Ph+ Ph+
Ph+Ph+
Ph+
Ph+ Ph+
Ph+Ph+ Ph+
Ph+Ph+
Ph+
Ph+Ph+
Ph+Ph+ Ph+
Ph+Ph+
Ph+
Ph+
Ph+
Ph+Ph+ Ph+
Ph+Ph+
Ph+
Ph+
Ph+
Ph+Ph+ Ph+
Ph+Ph+
Ph+
Ph+
Ph+
Ph+Ph+ Ph+
Ph+Ph+
Ph+
Ph+
Ph+
Ph+Ph+ Ph+
Ph+Ph+
Ph+
Ph+
Ph+
Ph+Ph+
Ph+Ph+
Ph+
Ph+Ph+ Ph+
Ph+Ph+
Ph+
Ph+
Ph+
Ph+Ph+ Ph+
Ph+Ph+
Ph+
Ph+
Ph+
Ph+Ph+ Ph+
Ph+Ph+
Ph+
Ph+
The BCR/ABL amount measured by RQ PCR mirrors the number of cells less sensitive to Imatinib
BCR/ABL reduction
The persistent Ph-positive cells less sensitive to imatinib may potentially become prone to
progressionHigher the number, higher the risk!
Two major problems with imatinib therapy
• Resistance/Loss of Response and Progression
• Persistence of small amount of leukemic cells
Otherdefects
Imatinib
Imatinib not able to suppress the BCR-ABL TK
•Point mutations•BCR-ABL amplification•Insufficient IMA in cells
Clonal evolution
4 Critical regions
ATP binding loopa.a. that control the kinase
activation step
M244V D276G
P-loopCatalyticdomain
Activationloop
The map of mutations
V289A M343T E355G/D H396R/P S417Y
L248V T277A M351T/V L387M/F
G250E E255K/V F311L/I F317L F359V F382L E459K
Q252R/HV379I
F486S
A380TY253F/H T315I
Gatekeepers
Most frequent mutations
0
22
no
. o
f m
uta
tio
ns
21
123456789
1011121314151617181920
M24
4VL24
8VG
250E
Q25
2R/H
Y253F
/HE25
5K/V
D276G
T277A
P296H
F311L
/IT31
5IF31
7LM
343T
M35
1T/V
E355G
/DF35
9V/I
V379I
A380T
F382L
L387F
/MH39
6R/P
S417Y
E459K
/QF48
6S
P-loop
*Soverini et al GIMEMA-CML WP data on 297 matinib resistant patients (CML, Ph+ ALL)
Soverini et al., JCO 2005
DualInhibitors
Imatinibderivative
Gorre et al., Science. 2001
Wild-type T3151 MutantWild-type T3151 Mutant
Clone withT315I
Clone withMutation
Clone withoutmutations
Imatinib
Dasatinib ornilotinib
LBH orON012380
PhUPhU
PhU
PhR
PhR
Imatinib Imatinib
Ph+
Ph+Ph+ Ph+
Ph+Ph+
Ph+
Ph+
Ph+
Ph+Ph+ Ph+
Ph+Ph+
Ph+
Ph+ Ph+
Ph+Ph+ Ph+
Ph+Ph+
Ph+
Ph+Ph+
Ph+Ph+ Ph+
Ph+Ph+
Ph+
Ph+
Ph+
Ph+Ph+ Ph+
Ph+Ph+
Ph+
Ph+
Ph+
Ph+Ph+ Ph+
Ph+Ph+
Ph+
Ph+
Ph+
Ph+Ph+ Ph+
Ph+Ph+
Ph+
Ph+
Ph+
Ph+Ph+ Ph+
Ph+Ph+
Ph+
Ph+
Ph+
Ph+Ph+
Ph+Ph+
Ph+
Ph+Ph+ Ph+
Ph+Ph+
Ph+
Ph+
Ph+
Ph+Ph+ Ph+
Ph+Ph+
Ph+
Ph+
Ph+
Ph+Ph+ Ph+
Ph+Ph+
Ph+
Ph+
PhUPhU
PhU
PhUPhU
PhU PhUPhU
PhU
PhUPhU
PhU
PhUPhU
PhU
Blood 2006
CCRCCR
Not Not detecteddetected
6 6 9 9 12 12 1818PrePre 33 2424 2727 3030
4.04.0
3.03.0
2.02.0
1.01.0
Base lineBase line
Log
red
ucti
on o
f L
og r
educ
tion
of B
CR
-AB
LB
CR
-AB
L
92% 92% BCR-BCR-ABLABL
positive positive
Molecular response in IRIS trial
MonthsMonths
Ph+SC Ph+SC Normal
SC
Normal
SCNormal
SCNormal
SC
Normal
SCNormal
SC
CML cellsCML cells
Ph+ progenitors
Ph+ mature cells
Imatinib
Less sensitive progenitor
Ph+SC
Most patients who stop imatinib therapy, even when PCR neg,
relapse!
Peter Kistler
Small edit in first line of title
Michor et al., Nature 2005
Differentiated
Progenitors
Holyoake TL, Blood 2004Holyoake TL, Blood 2004
Punish the Parent not the Progeny
Bcr-Abl off? Bcr-Abl on?
The Imatinib concentration in the progenitor cells, due to the action of influx (OCT-1) and efflux (ABCB1) proteinsseems to represent a major determinant for the persistence-resistance of Ph-positive progenitors
Tessa Holyoake and Deb White
Ph+ cells that survive and
returnto “normality”
BCR-ABLinhibitio
n
BCR-ABLinhibitio
n
Ph+ cells
Apoptosis
The persistence of Ph-positive cells may be due to: - cells more resistant to imatinib- cells in which the BCR-ABL TK activity may be
suppressed without a great damage
Imatinib
Imatinib
The persistence of Ph-positive cells may be due to: - cells more resistant to imatinib- cells in which the BCR-ABL TK activity may be
suppressed without a great damage
The strategy to eradicate the persistence of this tricky Ph+ population must be
appropriate • Combination therapy?• Immunotherapy?
• University of Turin• Daniela Cilloni• Giovanna Rege Cambrin• Francesca Messa• Carmen Fava• Francesca Arruga• Ilaria Defilippi• Emanuela Messa• Alessandro Morotti• Enrico Gottardi• Emilia Giugliano• Anna Serra• Milena Fava
San Luigi Hospital-University of TurinSan Luigi Hospital-University of Turin
ICSG on CMLICSG on CML
