Abstract 651: Male mouse model of canine and human inflammatory breast cancer (IBC)

• Published in: Cancer research (Chicago, Ill.) Ill.), 2016-07, Vol.76 (14_Supplement), p.651-651
• Main Authors: Caceres, Sara, Peña, Laura, Illera, Maria J., Silvan, Gema, de andres, Paloma J., Gao, Hui, Woodward, Wendy A., Reuben, James M., Illera, Juan C.
• Format: Article
• Language: English
• ISSN: 0008-5472; 1538-7445
• DOI: 10.1158/1538-7445.AM2016-651

Inflammatory breast cancer (IBC) is an aggressive type of breast cancer with poor survival in women. Canine IBC has been proposed as a good surrogate model for the study of the human disease. Male breast cancer is a rare disease, accounting for less than 1% of all malignancies in men. Although rarely, IBC has been also found in men. The aim was to evaluate the capacity of male SCID mice to develop IBC tumors after the injection of canine and human IBC cell lines (IPC-366 and SUM149, respectively). Eighty SCID mice: 40 male and 40 females, 6-8 weeks old were used. Suspensions of 106 IPC-366 and SUM149 cells were implanted subcutaneously into the fourth inguinal mammary gland in 20 male and 20 female mice (of each cell line), respectively. Mice were inspected twice a week for the development of tumors. Tumors were monitored by palpation and measured by calipers. Mice were sacrificed when tumors reached 1.5 cm3 and tumors and organs were removed for immunohistochemical (IHC) characterization. A portion of tumor was used for hormonal analysis (Progesterone, Estradiol, Estrone sulphate, Testosterone, Androstenedione). Results revealed that IPC-366 reproduced tumors in 90% (male) vs 100% (female) after 2 weeks p.i. SUM149 reproduced tumors in 40% (male) vs 80% (female) at 4 weeks p.i. Both cell lines produced metastasis in lungs. Higher metastatic rates found in females than in males (IPC-366: 90% vs 20%; SUM149: 80% vs 50%). EIA hormonal analysis revealed that male tumors had higher T and SO4E1 concentrations compared to female tumors (p< 0.05). IHC analysis revealed that male and female tumors shared immunophenotipic characteristics. All xenografts were highly proliferative (high Ki-67 indexes), triple negative (ER-, PR-, HER-2-), vimentin positive and contained less than 10% of cells positive to AE1-AE3 and CK-14. In conclusion, IPC-366 and SUM149 cell lines can reproduce tumors in male mice capable of metastasize. Male and female xenograft models shared immunophenotypic characteristics. Male mice model would be useful for future IBC research using a different endocrine environment that could help to better understand the androgens function in canine and human IBC. Citation Format: Sara Caceres, Laura Peña, Maria J. Illera, Gema Silvan, Paloma J. de andres, Hui Gao, Wendy A. Woodward, James M. Reuben, Juan C. Illera. Male mouse model of canine and human inflammatory breast cancer (IBC). [abstract]. In: Proceedings of the 107th Annual Meeting of the American A