Penfluridol: an antipsychotic agent suppresses metastatic tumor growth in triple negative breast cancer by inhibiting integrin signaling axis

摘要

Metastasis of breast cancer, especially to the brain, is the major cause of mortality. The inability of anti-cancer agents to cross the blood-brain-barrier represents a critical challenge for successful treatment. In the current study, we investigated the anti-metastatic potential of penfluridol (PF), an antipsychotic drug frequently prescribed for schizophrenia with anti-cancer activity. We show that PF induced apoptosis and reduced the survival of several metastatic triple negative breast cancer (TNBC) cell lines. Additionally, PF treatment significantly reduced the expression of integrinα6, integrin β4, Fak, Paxillin, Rac1/2/3, and ROCK1 in vitro. We further evaluated the efficacy of PF in three different in vivo tumor models. We demonstrate that PF administration to an orthotopic model of breast cancer suppressed tumor growth by 49%. On the other hand, PF treatment inhibited the growth of metastatic brain tumors introduced by intracardiac or intracranial injection of breast cancer cells by 90% and 72%, respectively. PF-treated tumors from all three models exhibited reduced integrinβ4 and increased apoptosis. Moreover, chronic administration of PF failed to elicit significant toxic or behavioral side effects in mice. Taken together, our result indicate that PF effectively reduces the growth of primary TNBC tumors and especially metastatic growth in the brain by inhibiting integrin signaling, and prompt further preclinical investigation into repurposing PF for the treatment of metastatic TNBC.