Table 2.

Antitumor effect of MELKi, TOPKi. and ERAP on breast cancers

Inhibitors	Structure	Enzyme IC50	Growth suppressive effect in BC cell lines in vitro and in vivo	Ref.
OTS167		MELK: 0.41 nM	DU4475 (TNBC); 2.3 nM MDA-MB-231 (TNBC); 22.0 nM SUM-159 (TNBC); 67.3 nM MDA-MB-468 (TNBC);14 nM (3-day) BT-549 (TNBC); 21 nM (3-day) HCC70 (TNBC); 34 nM (3-day) T47D (luminal); 4.3 nM (106 nM;3-day) MCF-7 (luminal) 35 nM (3-day) MDA-MB-231 (25 mg/kg) in vivo MDA-MB-468 (5 mg/kg) in vivo MCF-7 (5 mg/kg) in vivo T47D(5 mg/kg) in vivo	[52, 56]
MELK8a		MELK:11.9 nM	MDA-MB-468 (TNBC);5.41 nM (3-day) BT-549 (TNBC); 8.05 nM (3-day) HCC70 (TNBC); 5.99 nM (3-day) T47D (luminal); >10 nM (3-day) MCF-7 (luminal) 6.06 nM (3-day) ZR-75-1(luminal); >10 nM (3-day)	[52, 63]
Compound 17		MELK:0.39 nM	MCF-10A no effect at 10 µM HCC70 (TNBC); >1.0 μM BT-549(TNBC);>1.0 μM	[64]
OTS514		TOPK:2.6 nM	DU4475 (TNBC); 14 nM MDA-MB-231 (TNBC); 14 nM T47D (luminal); 14 nM	[67]
OTS964		TOPK:28 nM	DU4475 (TNBC); 53 nM MDA-MB-231 (TNBC); 73 nM T47D (luminal); 72 nM	[67]
stERAP		BIG3-PHB2: Kd 3.52 μM	MCF-7 (luminal);1.02 μM KPL3C (luminal); 10 mg/kg (weekly) in vivo	[89]

The bold letters indicate the in vivo tumor efficacy