Targeting the D93 cryptic collagen epitope alters integrin α2β1-dependent cellular migration and collagen remodeling in metastatic breast cancer.

Targeting the tumor-associated extracellular matrix (ECM) offers a promising strategy for breast cancer therapy. During cancer progression, collagen remodeling within the ECM exposes cryptic collagen epitope sites that antibodies can selectively recognize. Here, we investigate the therapeutic potential of targeting the D93 cryptic collagen epitope in 3D human metastatic breast cancer spheroids derived from MDA-MB-231 and MCF10CA1a (M4) cell lines embedded in collagen type I hydrogels. Treatment with monoclonal antibody (mAb) D93 reduced cellular migration into collagen type I hydrogels, an effect likely mediated by integrin α2β1. Two-photon microscopy further revealed that breast cancer cells drive the exposure of D93 sites and alter collagen architecture at both the fiber and fibril levels. Interestingly, collagen remodeling was altered more in the MDA-MB-231 spheroid models whereas the reduction in cellular migration was more pronounced in the M4 spheroid models, indicating a cell-line specific response to mAb D93. Together, these findings suggest that mAb D93 may inhibit integrin α2β1-dependent metastatic migration in breast cancer.