In vivo intravoxel incoherent motion imaging in evaluation on drug resistance of human colon cancer SW480 in nude mice / 中国医学影像技术

ABSTRACT

Objective: To explore drug resistance of human colon cancer SW480 tumor in nude mice with intravoxel incoherent motion (IVIM) imaging in vivo and its feasibility. Methods Nude mice with human colon cancer SW480 tumor in the resistant group (n=5) and non-drug resistant group (n=5) underwent IVIM imaging when the longest tumor diameter was greater than 1.50 cm, and true-diffusion coefficient (D), pseudo-diffusion coefficient (D*) and perfusion fraction (f) of the tumor were measured. Then the mice were sacrificed, and the protein expression (Western Blot) of P-glycoprotein (P-gp), multidrug resistance-associated protein 1 (MRP1), protein kinase C (PKC), necrosis (HE stain), apoptosis (TUNEL) of tumors were detected. Correlation analysis on IVIM parameters and tumor protein expression was performed. Results: The D value of non-resistance group was higher than that of drug-resistant group (P0.05). Tumor necrosis areas of the two groups were similar, the nucleus of drug-resistant group was larger than that of non-resistant group, while cells were arranged more closely and cell density was larger. There was no statistical difference in the apoptotic index between the two groups (P>0.05). Protein expression of PKC, P-gp and MRP1 in the drug-resistant group was higher than those in non-resistant group (all P<0.05). The D value was negatively correlated with the expression of P-gp, MRP1 and PKC (all P<0.05). Conclusion: The D value of tumor in nude mice model may become a significant marker to in vivo evaluate drug resistance of nude mice with human colon cancer SW480 tumor.