Imaging in Stem Cell Transplant and Cell-based Therapy

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6.2.3 Bioluminescence Imaging

In recent years, bioluminescence imaging (BLI) has drawn much attention and is
commonly used in the preclinical drug development. It allows gaining insight in the
engraftment pattern, growth dynamics and therapy-related changes in the tumor
volume following treatment of xenograft tumors in mice (Fig. 6.3). In BLI geneti-
cally modified cells are transfected to express luciferase, which converts luciferin to
oxyluciferin in the presence of oxygen and emits photons [ 19 ]. Luciferase-derived
photon emission can be detected externally from the cells located several millime-
ters below the skin [ 20 ]. Further, luciferase and BLI do not affect the tumor growth
in vitro or in vivo and is efficiently used in cancer imaging [ 21 ]. In addition, BLI
can detect as few as 500 cells at specific anatomical sites in  vivo and allows

Fig. 6.1 X-radiographs
showing loss in the density
of human fetal bone in
myeloma-bearing mouse.
NOD/SCID/IL2Rγnull mice
after implantation of
human fetal bones were
engrafted with OPM2
myeloma cells. Bone
resorption can be seen in
the untreated control
mouse (upper panel) as the
time progressed, compare
to the Exp-NK treated
mouse (bottom panel)

0

4000

8000

12000

16000

20000

Day 0Day 7 Day 14 Day 21 Day 28

Circulating human immunoglobulins

in mouse PB

Hu

ma

n

Ig

G

(μg

/m

l)

Duration

Fig. 6.2 Human-Ig levels
in NOD/SCID/
IL2Rγnull-Hu model. Levels
of circulating hIg
determined by ELISA from
the mouse blood after
inoculation of OPM2
myeloma cells showed an
increase in tumor burden
with the progression of
time

6 MRI & PET for Evaluation of Myeloma in SCID-hu Mice