Hair Keratin KRT81 Is Expressed in Normal and Breast Cancer Cells and Contributes to Their Invasiveness

The study from April 11, 2017, demonstrated for the first time that the hair keratin gene KRT81 is expressed in both normal breast epithelial cells and breast cancer cells. The researchers found that the full-size 55-kDa KRT81 protein was present in various human breast cancer cell lines (MCF7, SKBR3, MDA-MB-231), normal human mammary epithelial cells (HMEC), and non-neoplastic cells (MCF10A). They confirmed the expression of the full-size KRT81, including its 5' region, in these cells. Localization of KRT81 was identified in the cytoplasm through immunohistochemical and immunofluorescence analyses. Functional studies involving siRNA-mediated knockdown of KRT81 in MCF10A cells showed a decrease in the expression of genes related to invasion, such as MMP9. Additionally, reduced MMP9 activity and diminished cell migration and invasion abilities were observed in KRT81-knockdown MDA-MB231 breast cancer cells. These findings suggest that KRT81 plays a role in the invasiveness of breast cancer cells.