The Potential Role of Cathepsin K in Non-Small Cell Lung Cancer

• Main Authors: Hui Yang, Jasmine Heyer, Hui Zhao, Shengxian Liang, Rui Guo, Li Zhong
• Format: Article
• Language: English
• Published: MDPI AG 2020-09-01
• Series: Molecules
• Subjects: NSCLC; Cathepsin K; cell proliferation; cell migration; cell invasion; mTOR
• Online Access: https://www.mdpi.com/1420-3049/25/18/4136

(1) Background: Cathepsin K has been found overexpressed in several malignant tumors. However, there is little information regarding the involvement of Cathepsin K in non-small cell lung cancer (NSCLC). (2) Methods: Cathepsin K expression was tested in human NSCLC cell lines A549 and human embryo lung fibroblast MRC-5 cells using Western blot and immunofluorescence assay. Cathepsin K was transiently overexpressed or knocked down using transfection with a recombinant plasmid and siRNA, respectively, to test the effects on cell proliferation, migration, invasion, and on the mammalian target of rapamycin (mTOR) signaling pathway. (3) Results: Expression of Cathepsin K was increased significantly in A549 cells and diffused within the cytoplasm compared to the MRC-5 cells used as control. Cathepsin K overexpression promoted the proliferation, migration, and invasion of A549 cells, accompanied by mTOR activation. Cathepsin K knockdown reversed the above malignant behavior and inhibited the mTOR signaling activation, suggesting that Cathepsin K may promote the progression of NSCLC by activating the mTOR signaling pathway. (4) Conclusion: Cathepsin K may potentially represent a viable drug target for NSCLC treatment.