PRKAA1 and cancer: AMPK activity is also involved in the resistance mechanisms that are induced by the anti-cancer agent cisplatin [16], and it has been reported that LKB1-null mouse embryonic fibroblasts (MEFs) are resistant to oncogene-induced transformation [17] and that H-Ras-transformed AMPKα1/α2-null MEFs are impaired in their ability to form tumors in an in vivo xenograft model [18].