Molecular Pathogenesis
Pathogenesis
of Multiple My
pyeloma &
MGUS
Overlapping early events
Several kinds of progression events
MGUS almost always precedes MM
Can MM and MGUS cells be distinguished?
Michael Kuehl
Stages: pre-malignant MGUS > MM > PCL > HMCL
Normal
Long-lived
Plasma cell
Clinical manifestations
? de novo MM
Germinal
Intra-
Intra
Ct
Extra-
Center
Extra
Myeloma
MGUS
Smoldering
medullary
medullary
B cell
Cell Line
MM
MM
MM (PCL)
(HMCL)
bone marrow stromal cell dependence
IL-
IL 6 dependence
dependence
angiogenesis
bone destruction
increased DNA labelling index
Chromosome content suggests 2 pathogenic
pathways, each occurring in ~50% of tumors
Hyperdipoid (HRD) (48-75 chromosomes)
multiple trisomies involving
involving 8 chromosomes
chromosomes
3, 5, 7, 9, 11, 15, 19, 21
primary IgH translocations
translocations in ~10%
Non-hyperdiploid (
y(NHRD) (<48 and/or >75
chromosomes)
primary IgH translocations in ~ 70%
Chromosome 13 monosomy/deletion: often an
an
early event in both pathways
Primary IgH Translocations in MM
Seven recurrent partners
40%
Three primary
py IgH TLC groups
11q13 (CYCLIN D1)
15
6p21
6p
(CY
(C CLIN
C
D3)
3)
3
12p13 (CYCLIN D2)
< 1
16q23 (
q(c-MAF -> CYCLIN D2)
4
20q11 (MAF B -> CYCLIN D2)
2
8q24 (MAF A -> CYCLIN D2)
< 1
4p16 (MMSET&FGFR3)
15
Sequential RB pathway disruption:
Early (MGUS & MM) => CYCLIN D dysregulation
Progression (MM) => inactivation of p18 or RB1
maf
4p16
D2
D1
D2
D1
11q13
q
6p21
D1
16q23 c-maf
FGFR3
+
Hyperdiploid
CCND1
CCND3
20q11 mafB
MMSET
D2
p16 INK4a
p15 INK4b
NONE
Cyclin D2
Cyclin D1
Cl
Cyc i
lin D3
D3
p18 INK4c
CDK 4, 6
CDK 4, 6
CDK 4, 6
p19 INK4d
G1
S
Phase
phase
P
P
P
P RB
E2F
RB
E2F
OFF
ON
Progression by secondary (Ig) translocations
What tr
t an
a sl
s ocat
o
i
cat ons ar
a e secondar
da y?
MYC: c- >> N- >> L-
OTHER secondary translocations
IgH(non-recurrent or rare partner)
IgL ( >> )
rarely IgH with one of seven recurrent partners
PRIMARY
SECONDARY
TIMING
very early
anytime*
B CELL SPECIFIC MECHANISM
yes**
no
STRUCTURE
simple
complex
PREVALENCE
70%NHRD;10%HRD
NHRD = HRD
HETEROGENEITY
no
sometimes
* MYC rare in MGUS but OTHER 2o TLC not rare in MGUS
** mostly IgH switching; sometimes somatic hypermutation
MYC RNA expression increased in MM tumors
with MYC rearrangements detected by array CGH
R.MYC5
10.0
P < 0.001
75
7.5
MYC 5.0
RNA
2.5
0.0
N
Y
PRE-MALIGNANT MGUS
- Age dependent prevalence: 3% for individuals > 50 years old
- Ml
Monoclonal Ig (M
(M-I)
Ig)
- MGUS is distinguished from MM by
<10% tumor cells in bone marrow
no secondary end organ damage (bone, hematopoietic, kidney)
- Stable number of tumor cells and secreted Ig
-Sporadic pro
pp
gression non-IgM MGUS to MM with same M-Ig
average rate, 1% per year
stratified by M-Ig level & isotype, serum free light chain, & % abnormal
plasma cells: 0.3
0.3 to > 5% per year
year
- Some have suggested that 50% or more of MM tumors occur de novo,
without a preceding MGUS phase
How often is MM preceded by MGUS
- 90 MM patients (WRAMC) for marrow transplant (1996-2004)
- Dept. of Defense serum
serum repository:
repository: active duty every
every 2 years
years
- 30 MM patients with sera > 2 years before diagnosis
- 130 sera 2-15 years before MM (median = 3.5 per patient)
- Three standard assays on all sera
SPEP, quantitative serum protein electrophoresis
IFE, non-quantitated immunofixation electrophoresis
sFLC, serum free light
,g
chain
Collaborator
B. Weiss
Walter Reed Army Medical Center
Three of 30 MM patients with no evidence of preceding MG
Sera results in MM patients with no prior MGUS
3
Closed circles, (+
,( ) by > 1 assay
Open circles, (-) by all 3 assays
IgG
IgD
Patients
Patients
2
1
13
12
11
10
9
8
7
6
5
4
3
2
10
Years prior to the diagnosis of myeloma
Years prior to the diagnosis of myeloma
27 of 30 patients with MGUS preceding MM
Progression from PPCD to myeloma
1
2
3
4
5
6
7
8
9
10
11
Closed
()
Red = IgG circles (+)
Red = IgG
12 Patients
Blue = IgD
13
Green =
Open LC/NS
circles (-)
Patients
Open circle = no PPCD
14
Filled circle = PPCD present
IgG
15
16
IgD
17
18
Light chain only
19
20
21
22
23
24
25
26
27
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
10
Years prior to the diagnosis of myeloma
Years prior to the diagnosis of myeloma
Rapid progression from MGUS to MM in four of 27 patients
Rapid progression from MGUS phase to MM in four patients
1
Red = IgG
Blue =
IgD
Green = LC/NS
Open circle = no MG
Filled circle = MG present
2
Patients
3
4
12
11
10
9
8
7
6
5
4
3
2
1
0
Years prior to the diagnosis of myeloma
Years prior to the diagnosis of myeloma
MGUS preceding MM:
results and conclusions
· Monoclonal I /MGUS
g
is d t
e
t
ec d
e
t
a least 2 5
. years
i
pr or to
diagnosis of MM in most patients:
27/30 patients (90%, 95% CI = 74-
74 97%)
· Four (13%) of the 27 patients progressed rapidly (< 7
years) through MGUS to myeloma
· Four (13%) light chain only MM evolved from light chain
only MGUS, both detected only by sFLC
· De novo MM might occur but clearly is the exception
exception
The RAS Mutation Paradox
N-RAS: MGUS & MM; higher prevalence in MM expressing CYCLIN D1
K-RAS: Ab
t
sen in MGUS; same
l
preva ence l
a l
ll types f
o MM
MM tumors
? A different role or just different timing for K- vs N-RAS mutations
No. N-RAS
K-RAS N+K-RAS
MGUS
39
0.08
0
0.06
MM
248
0.14
0.17
0.31
MM-D1# 131
0.22
0.17
0.39
MM-D2## 102
0.04
0.17
0.21
P<0.001 P<10-7
#
t(11;14) and D1/hyperdiploid
## t(4;14), MAF, and D2
Molecular pathogenesis of multiple myeloma
increased DNA labeling index
bone destruction
angiogenesis
?
Germinal
Extra-
Center
Intra-
MGUS
Smoldering
medullary
Myeloma
B cell
medullary
Myeloma
Myeloma
Cell Line
Myeloma
Karyotypic & epigenetic abnormalities
Secondary (Ig) TLC
1o Ig TLC
NFkB activating mutations
del13
MAPK dysregulation: N, K- RAS, FGFR3
Hyperdiploidy
PI3K dysregulation
p18, RB inactivation
MYC dysregulation
Cyclin D
p53 inactivation
dysregulation
COLLABORATORS
Kuehl lab
Mayo Clinic (Arizona)
Li
Le f
if B
l
Current
ergsage
Leslie Brents
Marta Chesi
Yulia Demchenko
Rafael Fonseca
Oleg Glebov
Adam Kinney
U. Arkansas
Adriana Zingone
John Shaughnessy
Jf
Je f
ff S
Recent alumni
awyer
Conny Cultraro
Bart Barlogie
Amel Dib
Ana Gabrea
NCI
Tim Peterson
Lou Staudt
Marina Martelli
Christina Annunziata
Ying Qi
Qi
Eric Davis
Yaping Shou
Ola Landgren
Sheila Teves
Walter Reed Army Medical Center
Brendan Weiss
Three possible fates of germinal center B cells:
Normal plasma
p
cells >> MGUS > ? de novo MM
G,A,E,D
? de novo MM
Progressive
Smoldering
Germinal
MGUS
MM
MM
Center
B cell
Normal
Plasma cell
Lymph node
Bone Marrow