Breast cancer is the second highest cause of cancer related deaths for women in developed countries. Breast cancer patients with distant metastasis at the time of diagnosis have an estimated 5-year relative survival rate of 26% as compared to a 99% survival rate of patients who have localized tumors. Evidence suggests that collagens play a role in enhancing the metastatic capability of breast cancer cells. Short chain collagen, collagen X, is encoded by the collagen type x alpha 1 chain (COL10A1) gene and is normally expressed exclusively by hypertrophic chondrocytes during endochondral ossification. Recently, COL10A1 gene expression has been found to be overexpressed in various tumor types, including breast tumors. It is hypothesized that an increase in COL10A1 expression may play a role in breast cancer metastasis. The goal of our project was to evaluate the role of collagen X in breast cancer metastasis using the MDA-MB-231 breast cancer cell line. Stable cell lines were generated to express either GFP only (MDA-VEC) or GFP tagged COL10A1 (MDA-COL). GFP and COL10A1 transcript and protein levels were examined to confirm overexpression of collagen X and transwell assays were used to determine changes in the invasive capability of the cells. Cells overexpressing collagen X demonstrated a higher rate of invasion suggesting that collagen X may play a role in enhancing the metastatic potential of breast cancer cells. Understanding the role collagen X plays in breast cancer metastasis may provide a mechanism for developing diagnostic and prognostic strategies for identifying patients whose breast cancer is more prone to metastasize. Citation Format: McKiernan K, Jimenez H, McEachern M, Hubbard J, O'Connell M. Role of collagen X in enhancing the metastatic potential of breast cancer cells using a MDA-MB-231 cell line model [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-07-16.