Experimental Study On Early Detection Of Bone Metastases In Breast Cancer Using MRI-based USPIO Tracing Technique

Objective:To investigate the feasibility of USPIO-labeled breast cancer cells encapsulated with cationic liposome and the effect of USPIO on the physiological characteristics such as proliferation of breast cancer cells.And through MRI in vivo tracking of USPIO target-labeled breast cancer cells in the nude mice in the process of movement,to provide a basis for early detection of bone metastasis early experimental basis.Methods:(1)The lipofectamine 2000 was mixed with different concentrations of USPIO,and to label the breast cancer cells.The magnetic labeling rate of the breast cancer cells was measured by Prussian blue staining;(2)The enhanced CCK-8 kit was used to observe the effect of different concentrations of USPIO on the proliferation of breast cancer cells;(3)Utilizing the methods described in(1)above,MRI scans of different concentrations of USPIO-labeled cell suspensions were performed in vitro to observe the signal changes between the groups;(4)Twelve nude mice were randomly divided into 2 groups,the bone metastasis model of breast cancer was replicated using the in situ implanted cancer cell method.The USPIO labeled breast cancer cells were injected into the experimental group and the breast cancer cells were injected into the control group.Cells and MRI scans were performed on the nude mice at 3 week,4 weeks,and 5 weeks postoperatively,and histological examinations were performed.(5)Statistical analysis of the data.Results:(1)After Prussian blue staining,a large number of blue-stained particles were seen in breast cancer cells,indicating that USPIO can effectively label breast cancer cells after lipofectamine 2000 modification,and with the increase of USPIO concentration,the magnetic labeling rate also increased;(2)When CCK-8 enhanced kit reaction was used,the absorbance values of different concentrations of USPIO were measured by a multi-functional automatic microplate reader.The USPIO at a concentration of 89.6?g/m L showed a certain inhibitory effect to the proliferation of breast cancer cells at 72h;concentrations below 89.6?g/m L have no significant effect on the breast cancer cells;(3)in vitro MRI experiments show that compared with the control group,when the USPIO concentration reached 25?g/m L,a low signal can be formed on the T2 WI sequence;(4)The bone metastasis model of breast cancer cells implanted in situ has some limitations,and the signal intensity on the MRI at the same time between the experimental group and the control group is not obvious Differences;(5)Statistical analysis showed that the magnetic labeling rates of USPIO-labeled breast cancer cells in different concentrations were statistically different(P<0.05).When the concentration was 89.6 ?g/m L,the breast cancer cells proliferation compared with the control group was significant difference at72h(P<0.05);While in vitro MRI imaging,when the concentration of 25 ?g/m L,compared with the control group the SI,with a significant difference(P <0.05).Conclusion:(1)USPIO modified with lipofectamine 2000 can safely and effectively label breast cancer cells;(2)Low concentration of USPIO has no effect on the proliferation of breast cancer cells,and is a safer cell-targeted tracer;(3)On the T2 WI sequence,when the concentration of USPIO is 25 ?g/m L,signal changes can be detected on MRI;(4)Breast cancer bone metastasis model replicating method for in situ implantation of cancer cells and targeted tracer cancer cells still need to be further discussion.