Topoisomerase I/II inhibitor 2 (compound 1a) is a DNA topoisomerase I/II dual inhibitor that significantly reduces xenograft tumor growth in a mouse model, indicating its potential use in treating liver cancer. It is a potent topoisomerase inhibitor with IC50 values of 6.83 μM and 9.82 μM for LM9 cells and Huh7 cells [1].

Topoisomerase I/II inhibitor 2 (compound 1a) exhibits strong anti-proliferative activity against cancer cell lines, particularly HuH7 and LM9 hepatocellular carcinoma cells, within 0-150 μM concentrations over 72 hours. At 20 μM for 24 hours, it does not cause DNA damage in HuH7 cells but does in LM9 cells. Its anti-proliferative effect is concentration-dependent, showing significant cell cycle arrest at G2/M phase at 0-20 μM for 48 hours and inhibiting cell proliferation in both cell lines after 1-2 weeks of treatment with 1.25-8 μM. The compound also reduces cell migration and invasion and downregulates MMP-9 expression in a concentration-dependent manner, with notable effects at 0-20 μM over 24 to 48 hours. Furthermore, it causes mitochondrial dysfunction and apoptosis at 3.5-20 μM over 48 hours. Across various cell lines, including a subset of hepatocellular carcinoma, colorectal, breast, gastric, lung, and leukemia lines, the compound is particularly effective in HuH7 and LM9 cells. Western Blot and cell cycle analyses support its role in inhibiting MMP-9 expression and arresting the cell cycle at the G2/M phase, indicating its potential as a targeted therapy for human hepatocellular carcinoma.