Cantharidin

Inhibits protein phosphatase 2A (Ki=0.19 μM) and PP1 (Ki=1.1 μM) [1]. Displays >500-fold selectivity over PP2B. Suppresses growth and migration of PANC-1 pancreatic cancer cells via phosphorylation and degradation of β-catenin [2]. Arrests G2/M transition via JNK/Sp1-dependent down-regulation of CDK1 [3]. Cell permeable. 

Warning: Avoid skin contact, may cause skin irritation or blistering.

References:

1) Honkanen (1993) Cantharidin, another natural toxin that inhibits the activity of serine/threonine protein phosphatases types 1 and 2A; FEBS Lett. 330 283

2) Wu et al. (2014) PP2A inhibitors suppress migration and growth of PANC-1 pancreatic cancer cells through inhibition on the Wnt/β-Catenin pathway by phosphorylation and degradation of β-catenin; Oncol. Rep., 32 513

3) Gong et al. (2015) PP2A inhibitors arrest G2/M transition through JNK/Sp1-dependent down-regulation of CDK1 and autophagy up-regulation of p21; Oncotarget, 6 18469