Pair Name	Epigallocatechin gallate, Bortezomib
Disease Info	[ICD-11: 2A00-2F9Z]	Solid tumour or cancer		Investigative
In Vivo Model	Four- to 6-week-old male athymic nu/nu mice were obtained from Harlan (Indianapolis, IN) and implanted subcutaneously with 5 × 106 RPMI/8226 multiple myeloma cells.
Result	(-)-epigallocatechin gallate (EGCG) and other polyphenols with 1,2-benzenediol moieties, effectively prevented tumor cell death induced by BZM in vitro and in vivo. This pronounced antagonistic function of EGCG was evident only with boronic acid-based proteasome inhibitors (BZM, MG-262, PS-IX), but not with several non-boronic acid proteasome inhibitors (MG-132, PS-I, nelfinavir). EGCG directly reacted with BZM and blocked its proteasome inhibitory function; as a consequence, BZM could not trigger endoplasmic reticulum stress or caspase-7 activation, and did not induce tumor cell death. Taken together, our results indicate that green tea polyphenols may have the potential to negate the therapeutic efficacy of BZM and suggest that consumption of green tea products may be contraindicated during cancer therapy with BZM.