Abstract A04: The role of surgical resection of primary tumor before the appearance of circulating tumor cells based on orthotopic allograft mouse model

Breast cancer causes death not because of the primary tumor in the breast but because of metastases in distant sites that gradually cause organ dysfunction. Circulating tumor cells (CTCs) are cells that have detached from the primary tumor or metastatic tumor site and entered the peripheral circulation. Using CTC-mouse model, we tested the hypothesis that curative resection prior to CTC appearance results in repression of tumor metastasis. In method, we implanted 1 x104 GFP expressing 4T1 cells in 4th or 5th mammary fat pad of 8 week-old BALB/cAnNCrl mice (n=69). Enumeration of CTCs was performed using a FACSCalibur flow cytometry system (Becton, Dickinson and Company, Cowley, U.K.). CTCs were considered positive if the number of counted cells is more than 5. First, to test the validity of our CTC count method using FACS, we conducted cell-spiking tests. Using phosphate-buffered saline (PBS) and human blood, 50, 200, 500, 1000 4T1/GFP tumor cells were spiked. The R2 between spiked tumor cells and counted cells were 0.930 for PBS and 0.975 for human blood, respectively. Next, we tested the correlation between CTC counts and tumor volume. In the results, tumor volume and the number of CTCs increased over time and tumor volume showed statistically significant correlation with CTCs (p<0.001). In most cases, CTC-positive mouse died 6 weeks after orthotropic transplantation of 4T1 cell lines. Then, to evaluate the role of surgery in early breast cancer with no CTC, we removed tr...
Source: Molecular Cancer Research - Category: Cancer & Oncology Authors: Tags: Animal Models: Poster Presentations - Proffered Abstracts Source Type: research