| Abstract: | The aim of this study was to successfully establish an orthotopic murine model using two
different human pancreatic adenocarcinoma cell lines and to propose a 3.0 tesla MRI
protocol for noninvasive characterization of this model. SW1990 and MIAPaca-2 tumor cells
were injected into the pancreas of BALB/C nu/nu mice. Tumor growth rate
and morphological information were assessed by 3.0 tesla MRI (T1WI, T2WI and DCE-MRI) and
immunohistology. Proliferation of SW1990 was significantly faster than that of MIAPaca-2
(P=0.000), but MIAPaca-2 mice had a significantly shorter survival than
SW1990 mice (41 days and 44 days respectively, P=0.027). MRI could
reliably monitor tumor growth in both cell lines: the tumors exhibiting a spherical growth
pattern showed a high-intensity signal, and the SW1990 group developed significantly
larger tumors compared with the MIAPaCa-2 group. There were no statistical differences
between the two groups in which tumor size was assessed using electronic calipers and an
MRI scan (P=0.680). Both tumors showed a slow gradual enhancement
pattern. Immunohistochemistry demonstrated tumor tissues showing high expression of Ki-67.
This model closely mimics human pancreatic cancer and permits monitoring of tumor growth
and morphological information by noninvasive 3.0 tesla MRI studies reducing the number of
mice required. |
