Increased protein kinase CK2 activity is involved in many human diseases such as cancer (1). In consequence CK2 is an emerging major target for drug design. Several indeno[1,2-b]indole-9,10-dione derivatives containing N5-isopropyl substitutions on the C-Ring were synthesized and have been reported as potent ATP-competitive CK2 inhibitors (2,3).
Here we report on the evaluation of these inhibitors, containing different substituents in the A- and D-rings, for their effects on various tumor cell lines: breast cancer cells MCF-7, lung carcinoma cells A427 and epidermal cancer cell line A431.
The most potent CK2 inhibitor contains an O-prenyl residue R1 and exhibits an IC50 value of 0,025 µM. Treatment of MCF-7 cells with 20 µM of that compound for 24 h results in a reduction of the total cell number by 90%. Most of the remaining cells exhibited apoptotic morphology and showed nearly none proliferating activity. In contrast treatment of A431 cells and A427 cells caused only a moderate decrease of cell proliferation by 30% for all tested compounds.
This study shows that potent CK2 inhibitors as tested can exhibit distinct effects on different tumor cell lines. Compound containing an O-prenyl residue R1 appears to be an antiproliferating agent with high activity toward MCF7 cells.
References
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- Alchab, F. et al : Pharmaceuticals 2015, 8, 279-302
- Gozzi, et al: J. Med. Chem 2015, 58, 265-277