CD44 inhibits the transition of ductal carcinoma in situ to invasive breast carcinoma

[[abstract]]Ductal carcinoma in situ (DCIS) transition to invasive tumor is a big problem for breast cancer. The human MCF10DCIS.com cell line (abbreviated as MCF10DCIS) is derived from the human MCF10A breast epithelial cell line. The MCF10DCIS xenografts are similar to human high grade comedo DCIS. In the xenograft assay, MCF10DCIS cells form DCIS-like lesion, remain as DCIS-like lesion in the first several weeks, and then progress into invasive carcinoma. Thus, it is an excellent model to study human breast cancer transition from DCIS to invasive carcinoma. We investigated the role of CD44 in breast cancer transition from DCIS to invasive carcinoma by knockdown the expression of CD44 in the MCF10DCIS xenograft model. Our results show that knockdown of CD44 expression in the MCF10DCIS cells promotes DCIS transition to invasive carcinoma. Our finding is supported by a previous study that showed CD44 expression is higher in DCIS than in invasive breast carcinomas for human patients. Furthermore, we will present our ongoing studies for the underlying mechanisms. Our findings have important implications for breast cancer