title: The Novel PIM1 Inhibitor NMS-P645 Reverses PIM1-Dependent Effects on TMPRSS2/ERG Positive Prostate Cancer Cells And Shows Anti-Proliferative Activity in Combination with PI3K Inhibition.
abstract: PIM1 is over-expressed in multiple tumors, including prostate cancer (PCa). PIM1 upregulation is mediated by direct binding of the ERG transcription factor to its promoter. About 50% of PCa cases are characterized by the presence of the TMPRSS2/ERG fusion, leading to ERG over-expression and thus to PIM1 transcriptional activation. PIM kinases are considered as weak oncogenes, but when combined with additional genetic alterations can induce strong transforming effects. Here we show anti-proliferative activity of the newly described PIM1 inhibitor NMS-P645 in combination with the PI3K inhibitor GDC-0941 in TMPRSS2/ERG positive and negative PCa cells. Treatment with NMS-P645 alone can reverse PIM1-mediated pro-survival signals in prostate cells, such as activation of STAT3 through Tyr705 phosphorylation and resistance to taxane-based treatments, but does not exert a strong anti-tumoral effect. However, the simultaneous treatment with NMS-P645 and GDC-0941 induces a significant anti-proliferative response in PCa cells. These results support the use of combination strategies with PIM and PI3K inhibitors as effective treatment for PCa cases.
authors.affiliation: School of Medicine and Surgery, University of Milan-Bicocca, Monza, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Mologni
authors.affiliation: School of Medicine and Surgery, University of Milan-Bicocca, Monza, Italy.
authors.forename: Vera
authors.initials: V
authors.lastname: Magistroni
authors.affiliation: Nerviano Medical Sciences srl, Nerviano, Milan, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Casuscelli
authors.affiliation: Nerviano Medical Sciences srl, Nerviano, Milan, Italy.
authors.forename: Marisa
authors.initials: M
authors.lastname: Montemartini
authors.affiliation: School of Medicine and Surgery, University of Milan-Bicocca, Monza, Italy;; Hematology and Clinical Research Unit, San Gerardo Hospital, Monza, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Gambacorti-Passerini
keywords: PI3K; PIM1; Prostate cancer; inhibitor.; kinase