The Hypercoagulability of a Murine Breast Cancer Model with Pulmonary Metastasis
Breast cancer is the commonest malignancy cancer in women. Accumulated research showed that more than 60% of patients with malignant tumor were accompanied by hypercoagulable state, which in turn cause cancer progression, followed by long distant metastasis, alert the worse tumor prognosis and even affect treatment strategy. In the clinical study, we showed that the MA (mm) were significantly higher in the patients with stage IV breast cancer than in stage I/II/ III patients(P=0.01), which indicated that platelet hyperfunction was positively associated with tumor metastasis in breast cancer patients. In order to explore the relational mechanisms, we were committed to construction of efficient models in vivo and in vitro. In vivo study, as tumor-bearing period (TBP) and postoperative incubation period (PIP) are two key factors for coagulation and metastasis, we established 4T1-luc breast-tumor-bearing mice model of 4 groups (1a= TBP25+PIP17, 1b= TBP25+PIP1, 1c= TBP20+PIP17, 1d= TBP20+PIP1) with different TBP and PIP. Through evaluation of the breast tumors, lung metastases, animal welfare, operational feasibility and TEG Assay, indicated that: Lung metastasis and hypercoagulability were successfully established in all tumor groups; The TBP and PIP were both played a decisive role in the occurrence of lung metastasis; The model hypercoagulation state was characterized not by coagulation factors, but by the hyperactivity of fibrin and platelet. Given animal welfare and operational feasibility, recommended 4Tl-luc cells be injected into the fourth intramammary gland fat pad with 1 x 106, and with TBP of 3 weeks and PIP of 2 weeks, then an ideal in vivo model can be established. In vitro study, we established an in vitro model (platelet-breast cancer co-action) by platelets (female BALB/c mice) and 4T1 cells co-incubation for 30 minutes (represent the early phase of platelet-breast cancer co-action in vivo) or 24 hours (represent the late phase of platelet-breast cancer co-action in vivo), then the co-incubation supernatants were obtained by differential centrifugation. Through evaluation of the physical characteristics and procoagulant activity of the supernatants, indicated that co-incubation of platelets and 4T1 cells could activate each other and promote the release of substance and procoagulant activity with prolonging the co-incubation time, and the reaction supernatants can be used for interest factors detection and bioactivity verification. In conclusion, we provided powerful hypercoagulation-breast-cancer model for research in this field in vivo and in vitro, which will also provide important insights into the intervention of hematological metastasis in breast cancer.
Keywords: Breast Cancer, Hypercoagulable State, In Vivo Model, In Vitro Model