Fluorescent Proteins as Visible In Vivo Sensors - Progress in Molecular Biology and Translational Science - page 394

in the PV, liver metastasis resulted that contained GFP spleen cells. These
results suggest that liver metastasis requires the presence of stromal cells. 23
5. FLUORESCENT TUMORGRAFTS MADE FROM HUMAN
CANCER PATIENTS
5.1. Multicolor palette of fluorescent proteins for lighting
up patent tumors in mouse models
Tumor specimens from patients with from pancreatic cancer were initially
established subcutaneously in SCID-NOD mice immediately after surgery.
The patient tumors were then harvested from SCID-NOD mice and pas-
saged orthotopically in transgenic nude mice ubiquitously expressing RFP.
The primary patient tumors acquired RFP-expressing stroma. The RFP-
expressing stroma included CAFs and tumor-associated macrophages
(TAMs). Further passage to transgenic nude mice ubiquitously expressing
GFP resulted in tumors and metastasis that acquired GFP stroma in addi-
tion to their RFP stroma, including CAFs and TAMs and blood vessels.
The RFP stroma persisted in the tumors growing in the GFP mouse. Fur-
ther passage to transgenic nude mice ubiquitously expressing CFP resulted
in tumors and metastasis acquiring CFP stroma in addition to persisting
RFP and GFP stroma, including RFP- and GFP-expressing CAFs and
TAMs and blood vessels ( Fig. 10.4 ). 24
5.2. Lighting up metastasis from patient tumors in mouse
models
Primary patient tumors acquired GFP-expressing stroma. Subsequent liver
metastases and disseminated peritoneal metastases maintained the stroma
from the primary tumor and possibly recruited additional GFP-expressing
stroma, resulting in their very bright fluorescence. The GFP-expressing
stroma included CAFs and TAMs in both primary and metastatic tumors.
This imageable model of metastasis from a patient tumor is an important
advance over patient “tumorgraft” models currently in use, which are
implanted subcutaneously, do not metastasize, and are not imageable. 25
5.3. Noninvasive fluorescence imaging of patient tumors
in mouse models
The tumors from pancreatic cancer patients, with very bright GFP and RFP
stroma, as described above, were orthotopically passaged to noncolored
nude mice. The brightly fluorescent patient tumors could be non-invasively