Bone Anabolism and Tumor
Growth in Myeloma
Shmuel Yaccoby, PhD
Myeloma Institute for Research and Therapy
University of Arkansas for Medical Sciences

Disclosure
No conflicts of interest

Contrasting Effects of Bone Resorption
and Bone Formation on MM
Yaccoby, BJH 2010

Consequences of Osteoblast Activation
MM Suppression:
1. Restoring "coupling" may reduce osteoclast activity.
2. Increased production of MM restraining factors.
3. Recovering hematopoiesis and immune function.
4. Reconstructed osteoblastic niche replaces the MM
osteoclastic/reactive stroma niche.

Consequences of Osteoblast Activation
MM Stimulation:
1. Increasing MSC pool may also increase pool
of reactive stroma.
2. Osteogenic cells produce MM growth factors.
3. MM "stem cells" may compete with HSCs on
the restored osteoblastic niche.

Osteoblast Activating Agents Attenuate
MM Growth in Bone
· Anti-DKK1
(Yaccoby et al., Blood 2007; Fulciniti et al, Blood 2009)
· Wnt3a
(Qiang et al., Blood 2008)
· Lithium Chloride
(Edwards et al., Blood 2008)
· EphB4-Fc
(Pennisi et al., Blood 2009)
· TGF- inhibition
(Takeuchi et al., PLoS One 2010)
· Activin A inhibition (Vallet et al., PNAS 2010; Chantry et al., JBMR 2010)
· PTH
(Pennisi et al., PLoS One 2010)
· Bortezomib
(Edwards et al., AJH 2009; Pennisi et al., AJH 2009)
· MSC cytotherapy
(Yaccoby et al., 2006; Li et al., Stem Cell 2011)

EphrinB2-Fc and EphB4-Fc
Stimulate Bone Formation in MM Bones
CONT Fc
EphrinB2-Fc
EphB4-Fc
25
20
p<0.006
15
p<0.05
10
change)
5
(%
0
-5
-10
BMD
-15
Pre-RX Final
Pre-RX Final
Pre-RX Final
Resorption
Formation
Formation
Pennisi et al., Blood 2009

EphB4-Fc but Not EphrinB2-Fc
Inhibits MM Growth
Fc
EphrinB2-Fc
EphB4-Fc
600
80
60
400
40
200
20
p<0.002
p<0.001
0
0
Human Ig
Tumor area
(% change)
(%)
Pennisi et al., Blood 2009

Osteoblastogenesis Alone May Not
Be Sufficient For Restraining MM
Osteoclasts
Angiogenesis
.
20
.
.
30
o
p<0.05
o
15
lN
stN
20
10
sse
clao
-ve
10
te
5
p<0.02
p<0.05
cro
Os
0
Mi
0
Fc
EphrinB2- EphB4-Fc
Fc
EphrinB2- EphB4-Fc
Fc
Fc
Pennisi et al., Blood 2009

Intra-Bone Injected MSCs Promote Bone
Formation in MM Bone
CONT
MSC
Pre-Rx Final
(n=10)
(n=20)
Bone
60
CONT
resorption
40
change)
p<0.001
20
(%
Bone
0
Formation
BMD
MSCs
-20
Li et al., Stem Cells 2011
Yaccoby et al., 2006

Intra-bone Injected MSCs Inhibit MM
Growth in Bone
CONT
250
CONT
MM
200
MSCs
OC
p<0.001
150
g/ml)
n=20

MM
100
(Ig
50
MSCs
0
024
Weeks of treatment
OB

Intra-Bone Injected MSCs Disappear
Within 4 Weeks
3 d
14 d
28 d
*MSCs infected with luciferase-expressing lentivirus.

Intravenously or Intracardiacly Injected
MSCs Home to MM Bone
Implanted myelomatous bones
IV
IC

MSCs Home to Lytic Lesions in MM Bone
X-ray
Imaging
Osteolytic
MSCs
Lesion
IHC for GFP
MM
Bone
Exogenous
MSC

Weekly IV Injected MSCs Inhibit
MM Bone Disease
CONT
MSCs
Pre-Rx Final
0
CONT
-5
Prevention of
p<0.04
Bone Loss
change)
-10
.
n=10
(%
-15
MSCs
BMD
-20
200
CONT
No Effect on
150
g/ml)
MSCs
MM Burden
100
(Ig
50
0
Pre-Rx
2 wk
4 wk

Molecular Mechanism Study Design
Hg MM cell engraftment in SCID-hu mice
Hg MM cells:
Passaged in SCID-hu/SCID-rab
Express MMSET and DKK1
Intra-bone MSC injection
Immediately after
24 hrs after
cytotherapy (Control)
cytotherapy
n=8
n=6
Whole bone GEP

GEP Criteria and Overall Findings
0 Hrs
24 Hrs
Overexpressed (~60 genes)
Underexpressed (~50 genes)

Factors Affected by MSC Cytotherapy
· Anti-inflammatory
: TNFAIP6, CXCL14, PTGS2
· Proteases inhibitors
: TFPI2, PI15
· Antioxidants
: HMOX1
· TGF signaling
: SPON1, INHBA, TGFBI
· Macrophages (osteomacs)
: CD163

Potential Extracellular Factors
Mediating MSC Cytotherapy
· TFPI2
(Tissue factor pathway inhibitor 2)
· SPON1
(F-spondin)
· CXCL14
(Chemokine C-X-C motif ligand 14)
· TNFAIP6
(TNF­induced protein 6)
· ANGPTL2 & 4
(Angiopoietin-like 2 and 4)
· PI15
(Peptidase inhibitor 15)

PTH Promotes Bone Formation
and Attenuates MM Growth
Primary MM (n=10)
Hg MM Line
CONT
PTH
CONT
PTH
30
30
Bone
15
15
change)
0
change)
0
Formation:
(% -15
(% -15
BMD -30
-30
BMD
.
600
100
CONT
CONT
p<0.04
75
PTH
p<0.03
MM
400
g/ml)
PTH
g/ml)
50


Growth:
(
200
(
25
Ig
Ig
0
0
Pre-Rx
Final
Pre-Rx Final
Pennisi et al., PlosONE 2010

Environmental Pathways Targeted by PTH
Osteogenesis
cAMP/PKA
· RUNX2
·RGS1 & 2
·BGLAP
· Phosphodiesterases
· DECORIN
· SPARC
Others
·FGFR2
WNT
·PDGFA
· DKK1
·TGFB2
·LRP4
·FOXC1
·ROR2
· MSX1
Pennisi et al., PlosONE 2010

Anti-Inflammation Mediators are Among
Top Upregulated Genes by PTH
Fold Increase
· CXCL14
4
· F-Spondin
4
· ANGPTL2
4
· ANGPTL4
3
· PTGE3
3
· TNFAIP6
2
Pennisi et al., PlosONE 2010

MSC Cytotherapy or PTH Restore
Expression of Anti-MM Mediators
CXCL14
1500
1000
500
0
2000
SPON1
1000
Signal
0
GEP
5000
HMOX1
2500
0
Hg MM
Culutred Non-MM
MM
MM+MSC MM+PTH
Cells
MSC
Whole Bone

HMOX1 Inducer, Hemin, Promotes Osteoblast
Differentiation and Inhibits Osteoclast Formation
Control
Hemin
Osteoblast
Differentiation
Control
Hemin
Osteoclast
Formation
110±3
51±2
p<0.001

"Bone" Anabolic Protein Inhibits
Osteolysis and MM Growth
8
CONT
Bone Gene
CONT
0
6
Bone Gene
-5
g/ml)
4

-10
change)
.
p<0.05
(
2
-15
Ig
(%
0
-20
1234
BMD
-25
Weeks
H929 MM cells transduced with "bone" gene
were engrafted in SCID-hu mice.

Summary and Conclusions
1. Bone anabolic therapies upregulate
anti-inflammatory, anti-osteoclastogenic
and anti-angiogenic factors.
2. Source of these factors are mature
osteoblasts and/or certain hematopoietic
cells (e.g. BM macrophages).
3. These factors may restrain MM directly
("immediate effect") and indirectly ("long-
term effect") by altering bone remodeling
and BM cellularity.

Acknowledgment
Myeloma Institute
Yaccoby's Group
· Bart Barlogie
·Xin Li
· Joshua Epstein
· Sathisha UV
· Angela Pennisi
· John Shaughnessy
· Wen Ling
· Fritz Van Rhee
· Sharmin Khan
· Ya-Wei Qiang
· Rakesh Bam
· Ricky Edmond