Transgenic Mouse Models of
Plasma Cell Malignancies
University of Minnesota:
Brian Van Ness
Michael Linden
Mary Kvitrud
Kristin Boylan
Cell Signaling Technologies:
Gabe Cheung
Roby Poliekowicz
National Cancer Institute:
Sigfried Janz

---

Hypothesis
Targeted deregulation of anti-
apoptotic and oncogenic genes using
tissue and developmentally restricted
regulators will direct the development
of B- and plasma cell tumors in
transgenic mice.

---

GOALS
· Identify novel transcriptional
regulators with activity limited to B-
cells in late developmental stages
· Test the role of Bcl-X and other
L
putative genes involved in B-cell
neoplasia
· Develop new genetically-
engineered mouse models of B-
cell malignancies, including
myeloma

---

Immunoglobulin enhancers
demonstrate restricted
developmental activity
Pre-Pro-B
Pro-B
Pre-B
Immat-B
Mat-B
PC
3' Kappa Enhancer
Mu Heavy
Chain Enhancer
Enhancer elements near
IgH-C switch region

---

The 3'KIgE targets Bcl-XL
expression to the lymphoid cells

---

The 3'KE/Bcl-X mice develop
L
immunoglobulinemia
LMC
LMC
MYC
MYC
BCL-XL
BCL-XL
BCL-XL
BCL-XL/MYC
BCL-XL/MYC
A)
Albumin
Heavy
Light
Isotype Specific Ig Production
10000
B)
*
*
1000
*
*
*
Concentration
100
(ug/ml)
IgM
IgG1
IgG2a
IgG2b
IgG3
IgA
IgE #
Isotype
LMC (n=9)
* p<0.05
BCL-XL (n=12)
# ng/ml

---

3'KE/Bcl-X mice develop
L
hyaline casts and plasma cell foci
A
B
*
CD138 stain
C
D
(Images captured by the University of Minnesota Histopathology Core)

---

3'KE/Bcl-XL Mice
Young mice develop immunoglobulinemia,
polyclonal lymphoproliferation
Aged mice develop polyclonal plasma cell
foci and renal tubular casts
Mice do NOT develop tumors

---

IgH-MycC_ knock-in
­ a novel approach to target aberrant c-Myc
expression
3'KE/Bcl-X (FVB/N)
L
c-Myc knocked-in the C1-C2
locus of the Ig heavy chain
Elevated c-Myc expression in
activated/late B- and plasma cells
X
[Sigfried Janz -NCI]
IgH-MycC_ (129SvJ x C57BL/6) 3'KE/Bcl-XL mouse crossed to
the IgH-MycC_ mouse
Hypothesis ­ the combination of
enhancers used to co-express
Bcl-XL and c-Myc will
effectively target plasma cells

---

3'KE/Bcl-X x IgH-MycC_ mice demonstrate a
L
median survival of 18 weeks
( 3'KE/Bcl-X x IgH-MycCmu)
L
100
Bcl-XL
80
c-Myc
60
Bcl-X x c-Myc
L
survival
40
Percent
20
0
N=20, each group
0
50
100
150
200
250
300
350
400
Days
Bcl-X (FVB/N), c-Myc (129SvJ x C57BL/6), Bcl-X x c-Myc (mixed genetic background)
L
L

---

3'KE/Bcl-XL x IgH-MycC_ mice develop
bone marrow and spleen plasmacytoses
WT
IgH-MycC_
Myc x BclxL
Bone marrow
B220-/CD138+
B220
Plasma cells
CD138
CD3
Spleen
B220
B220
CD138
Lymph node
B220
CD138

---

3'KE/Bcl-XL x C-Myc mice develop
B- and plasma cell malignancies
DP #1
DP #2
1
2
Blood
Liver
Liver
Thymus
Blood
Marrow
Spleen
Thymus
Liver
Tail
Germline
(Images captured by the University of Minnesota Histopathology Core)

---

PI staining of tumor cells shows
higher DNA content
Control Splenic
B cell
0
200
400
600
800
1000
FL2-W
Malignant PCs
0
200
400
600
800
1000
FL2-W
2n

---

Spectral karyotyping mouse Plasma Cell Tumors
shows chromosomal instability
#1
+Ch1
T4D/E;9A
+Ch15
+Ch16
+Ch17
#2
+Ch5
derT4D;12F

---

Gene expression profiles in human myeloma
From J. Shaughnessy, University of Arkansas

---

Human myeloma and mouse plasma cell tumors
show similar gene expression patterns distinct
from normal plasma cells - ortholog comparisons
Normal PC
Human MM
Mouse
PCT

---

Tumor adoptively transferred
Spleen versus BM localization changes PC GEP
SPLEEN
BM

---

Genetic modifications of mouse
plasma cell tumors
Lenti Viral vectors
- From Dr. Nik Somia

---

GFP Tracking PC Tumors
A
B
C
D

---

FUTURE
· Develop mouse plasma cell tumor panel
-> showing genetic heterogeneity
· Define protein and gene expression profiles
-> link to human profiles (ortholog comparisons)
· Genetic modifications with lenti viral infection
-> add expression (mut Ras)
-> block expression (bcl-xL, DKK, EZH2)
· Identify therapeutic responses

---