【Animal Modeling】-Mice model of lung metastasis and postoperative recurrence after bone marrow injection

  Objective: To establish a model of bone marrow injection to treat lung metastasis and postoperative recurrence, to clarify the superiority and feasibility of the model established by bone marrow injection, and to provide a new research basis for the study of lung metastasis of malignant tumors.

  Method: Divide mice into chest pad injection group, subcutaneous injection group, tail vein injection group and bone marrow injection group. Use 4T1 cells to establish different models and observe the growth, survival and metastasis efficiency of different groups of primary tumors. Different numbers of 4T1 cells were injected to observe the time of lung metastasis. The postoperative recurrence model was constructed by injecting 4T1-luc cells into the bone marrow. The mice were divided into an artificial amputation group, a 3-day amputation group, a 7-day amputation group, and a 10-day amputation group. Observe the mice by in vivo imaging.

  Result: Compared with chest pad injections and subcutaneous injections, bone marrow injections do not affect the growth of primary tumors, but their survival time is significantly reduced. Compared with chest pad injection, subcutaneous injection and tail vein injection, bone marrow injection has the highest lung metastasis efficiency. Bone marrow injection requires only 1 x 105 4T1 cells to cause lung metastasis on the 12th day. Model mice injected with bone marrow will still cause lung metastasis and primary tumor recurrence after resection.

  Conclusion: We have successfully established a mouse model of lung metastasis established by bone marrow injection and a mouse model of postoperative recurrence. The mouse model using this injection method has the characteristics of short survival time and high metastasis efficiency, and is the mechanism of malignant tumor lung metastasis and drug screening.