TABLE 2

Solute carriers associated with cellular accumulation of methotrexate

Drug [Alias]	Mechanism of Action	Principle Side Effects	Transporters	References
Methotrexate [Trexall]	Interferes with folate metabolism	Myelosuppression	SLC22A6 (OAT1)^{^a} SLC22A7 (OAT2)^{^a} SLC22A8 (OAT3)^{^a}^,^{^b} SLC22A9 (OAT4)^{^a} SLCO1A2 (OATP1A2)^{^a}^,^{^b} SLCO1B1 (OATP1B1)^{^a}^,^{^b}^,^{^c} SLCO1B3 (OATP1B3)^{^a}^,^{^b} SLCO4C1 (OATP4C1)^{^a} SLC19A1 (RFC)^{^a}^,^{^c} SLC46A1 (PCFT)^{^a}	(Abe et al., 1999; Sun et al., 2001; Takeda et al., 2002; Mikkaichi et al., 2004; Mori et al., 2004; Badagnani et al., 2006; van de Steeg et al., 2009, 2013; Zhao et al., 2009; Sowers et al., 2011)
		Mucositis
		Dermatological toxicity (skin rash and/or nail changes)
		Renal toxicity
		Neurotoxicity

↵^a Evidence of drug uptake being regulated by solute carriers in vitro.
↵^b Evidence of drug uptake being regulated by solute carriers in vivo.
↵^c Evidence of drug uptake being regulated by solute carriers in patient populations.