In a clinically-relevant model of 4 week, low-dose
cisplatin-induced AKI, mice were injected subcutaneously with
non small cell lung cancer (NSCLC) cells that harbor an activating Kirsten rat
sarcoma viral oncogene homolog (KRAS)G12V mutation. Phospho extracellular signal-regulated kinase1/2 (pERK1/2) expression in kidney and
tumors was decreased by the MEK1/2 inhibitors,
U0126 and
trametinib, that potently inhibit pERK1/2.
U0126 resulted in a significant improvement in kidney function, acute tubular
necrosis (ATN) and tubular cell apoptosis in mice with AKI. Genes that were significantly decreased by
U0126 were
heat shock protein 1,
cyclin-dependent kinase 4 (CDK4) and stratifin (14-3-3σ).
U0126 resulted in a significant decrease in
tumor weight and volume and significantly increased the chemotherapeutic effect of
cisplatin.
Trametinib, a MEK1/2 inhibitor that is FDA-approved for the treatment of
cancer, did not result in functional protection against AKI or worse AKI, but dramatically decreased
tumor growth more than
cisplatin. Smaller
tumors in
cisplatin or MEK1/2 inhibitor-treated mice were not related to changes in
microtubule-associated proteins 1A/1B light chain 3B (LC3-II), p62, cleaved
caspase-3,
granzyme B, or
programmed death-ligand 1 (PD-L1). In summary, despite ERK inhibition by both
U0126 and
trametinib, only
U0126 protected against AKI suggesting that the protection against AKI by
U0126 was due to an off-target effect independent of ERK inhibition. The effect of
U0126 to decrease AKI may be mediated by inhibition of
heat shock protein 1, CDK4 or stratifin (14-3-3σ).
Trametinib was more effective than
cisplatin in decreasing
tumor growth, but unlike
cisplatin,
trametinib did not cause AKI.