Panoply™ Human CTSK Over-expressing Stable Cell Line

The role of cathepsin K (CTSK) in the pathogenesis and progression of gastric cancer (GC) remains unclear. Here, researchers demonstrate that CTSK is significantly upregulated in GC. Bioinformatics analysis showed that GC patients with high CTSK expression exhibited enrichment of a set of hallmark genes associated with angiogenesis, epithelial-mesenchymal transition (EMT), inflammatory responses, KRAS signaling pathway activation, TNFα signaling pathway (via KFκB), IL2-STAT5 signaling pathway, and IL6-JAK-STAT3 signaling pathway. Furthermore, these patients also showed elevated levels of M2 macrophage infiltration, which was associated with poor prognosis. In vitro experiments confirmed that CTSK overexpression leads to enhanced proliferation and invasion of GC cells. However, further evaluation is needed to determine the impact of CTSK on these cell migration abilities. These results suggest that CTSK may promote the occurrence and development of GC by enhancing the invasiveness of GC cells, participating in tumor-associated epithelial-mesenchymal transition (EMT), and promoting the establishment of an immunosuppressive tumor microenvironment (TME).

Based on the CCK-8 results, compared with the control group, the OD450nm value of CTSK-knockdown AGS cells was decreased, while the OD450nm value of CTSK-overexpressing MKN45 cells increased after 48 hours of culture (Figure 1A). Similarly, the number of colonies formed by CTSK-knockdown AGS cells was reduced, while the number of colonies formed by CTSK-overexpressing MKN45 cells increased after 1 week of culture (Figures 1B and 1C). The number of apoptotic cells in both early and late stages increased in AGS cells with suppressed CTSK gene expression, while the number of apoptotic cells decreased in MKN45 cells with enhanced CTSK gene expression (Figure 1D). The total apoptosis rate of each group of cells was measured, and the results showed that the total apoptosis rate of CTSK-overexpressing AGS cells was significantly increased, while the total apoptosis rate of CTSK-knockdown MKN45 cells was significantly decreased (Figure 1E). The cell migration and invasion abilities were assessed using scratch assays and Transwell assays. The results showed that, compared with the control group, the scratch healing rate of CTSK knockdown AGS cells was reduced, while the scratch healing rate of CTSK overexpressing MKN45 cells was increased. However, these differences were not statistically significant (Figure 1F, G). Furthermore, the researchers quantitatively analyzed the number of cells that crossed the Matrigel membrane in CTSK knockdown AGS cells, CTSK overexpressing MKN45 cells, and their respective control groups after 12 and 24 hours of culture. The results showed that, compared with the control group, the number of invasive cells was reduced in CTSK knockdown AGS cells, while the number of invasive cells was increased in CTSK overexpressing MKN45 cells (Figure 1H). These results indicate that CTSK enhances the proliferation and invasion of gastric cancer cells.

Figure 1. In vitro experiments confirmed the role of different expressed levels of CTSK on GC cells. (Feng Z, et al., 2024)