Changes in the methylation level of genes containing LINE-1 alter host gene regulation.
Aim: This study demonstrates that paracrine signaling of breast cancer influences the epigenetic regulation of stromal cells.
Methods: We proved in vitro and in vivo breast cancer promoted LINE-1 methylation exists exclusively in female stromal cells.
Results: Genes containing LINE-1 of breast cancer stromal cells were upregulated. Furthermore, one of the genes, MUC-1, was demonstrated to have expression in plasma cells from the lymph nodes of patients with lymph node metastasis or micrometastasis.
Conclusion: Breast cancer sends a paracrine signal to stroma cells causing LINE-1 epigenetic regulation. Moreover, the regulated genes in stroma cells are potential biomarkers for detecting breast cancer micrometastasis.
Keywords: LINE-1 hypermethylation; breast cancer; tumor supporting tissue.