proTAME

proTAME is a cell-permeable APC/C (Anaphase Promoting Complex/Cyclosome) inhibitor^[1]. proTAME is converted to TAME (Tosyl-L-Arginine Methyl Ester) by intracellular esterases, and TAME specifically inhibits the activity of APC/C, thereby inducing cell cycle arrest in metaphase and subsequently leading to cell death^[2]. proTAME is commonly used in research on cell cycle regulation and cancer-related studies^[3][4].

In vitro, proTAME (5, 10, 20, 50 or 100μM; 3h) treatment shows dose-dependent metaphase arrest in mammalian oocytes and early cleavage embryos, and the metaphase arrest induced by this drug does not require spindle assembly checkpoint (SAC) activity^[5]. Treatment of OVCAR-3 cells with proTAME(5, 10, 20, 50 or 100μM; 6h) inhibits cells growth with an IC₅₀ of 12.5μM^[6]. Treatment of MCL and DLBCL cell lines with proTAME (3, 6 and 12µM) for 24h induced a prolonged metaphase, resulting in accumulation of the APC/C-Cdc20 substrate cyclin B1, inactivation/degradation of Bcl-2 and Bcl-xL and caspase-dependent apoptosis^[7].

References:
[1] Zeng, X., Sigoillot, F., Gaur, S., Choi, S., Pfaff, K. L., Oh, D. C., Hathaway, N., Dimova, N., Cuny, G. D., & King, R. W. (2010). Pharmacologic inhibition of the anaphase-promoting complex induces a spindle checkpoint-dependent mitotic arrest in the absence of spindle damage. Cancer cell, 18(4), 382–395.
[2] Zeng, X., & King, R. W. (2012). An APC/C inhibitor stabilizes cyclin B1 by prematurely terminating ubiquitination. Nature chemical biology, 8(4), 383–392.
[3] Lara-Gonzalez, P., & Taylor, S. S. (2012). Cohesion fatigue explains why pharmacological inhibition of the APC/C induces a spindle checkpoint-dependent mitotic arrest. PloS one, 7(11), e49041.
[4] Mayah, A., Arenas, R. B., Bastida, A., & Bolanos-Garcia, V. M. (2025). The Use of APC/C Antagonists to Promote Mitotic Catastrophe in Cancer Cells. Methods in molecular biology (Clifton, N.J.), 2874, 207–213.
[5] Radonova, L., Svobodova, T., Skultety, M., Mrkva, O., Libichova, L., Stein, P., & Anger, M. (2019). ProTAME Arrest in Mammalian Oocytes and Embryos Does Not Require Spindle Assembly Checkpoint Activity. International journal of molecular sciences, 20(18), 4537.
[6] Raab, M., Sanhaji, M., Zhou, S., Rödel, F., El-Balat, A., Becker, S., & Strebhardt, K. (2019). Blocking Mitotic Exit of Ovarian Cancer Cells by Pharmaceutical Inhibition of the Anaphase-Promoting Complex Reduces Chromosomal Instability. Neoplasia (New York, N.Y.), 21(4), 363–375.
[7] Maes, A., Maes, K., De Raeve, H., De Smedt, E., Vlummens, P., Szablewski, V., Devin, J., Faict, S., De Veirman, K., Menu, E., Offner, F., Spaargaren, M., Moreaux, J., Vanderkerken, K., Van Valckenborgh, E., & De Bruyne, E. (2019). The anaphase-promoting complex/cyclosome: a new promising target in diffuse large B-cell lymphoma and mantle cell lymphoma. British journal of cancer, 120(12), 1137–1146.