2014 年 63 巻 4 号 p. 403-413
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.
