The pathophysiological significance of PPM1D and therapeutic targeting of PPM1D-mediated signaling by GSK2830371 in mantle cell lymphoma.
PPM1D is a serine/threonine phosphatase that negatively regulates key DNA damage response proteins, such as p53, p38 MAPK, histone H2A.X, and ATM. We investigated the pathophysiological significance of PPM1D and its therapeutic targeting by the novel PPM1D inhibitor GSK2830371 in mantle cell lymphoma (MCL). Oncomine-based analyses indicated increased PPM1D mRNA levels in MCL cells compared with their normal counterpart cells. Higher PPM1D expression was associated with higher expression of the proliferation gene signature and poorer prognosis in patients. Eight MCL (three p53 wild-type and five mutant) cell lines were exposed to GSK2830371. GSK2830371 inhibited the cell growth, being prominent in p53 wild-type cells. GSK2830371 induced apoptosis in sensitive cells, as evidenced by induction of phosphatidylserine externalization and loss of mitochondrial membrane potential. p53 knockdown de-sensitized cell sensitivity. GSK2830371 increased the levels of total and Ser15-phosphorylated p53, and p53 targets p21 and PUMA. GSK2830371 and the MDM2 inhibitor Nutlin-3a acted synergistically in p53 wild-type cells. Interestingly, GSK2830371 sensitized MCL cells to bortezomib and doxorubicin in p53 wild-type and mutant cells; p38 signaling appeared to be involved in the GSK2830371/bortezomib lethality. PPM1D inhibition may represent a novel therapeutic strategy for MCL, which can be exploited in combination therapeutic strategies for MCL.
Department of Hematology, Respiratory Medicine and Oncology, Division of Medicine, Saga University, Saga, Japan.
Kensuke
K
Kojima
Department of Hematology, Respiratory Medicine and Oncology, Division of Medicine, Saga University, Saga, Japan.
Aya
A
Maeda
Department of Hematology, Respiratory Medicine and Oncology, Division of Medicine, Saga University, Saga, Japan.
Mariko
M
Yoshimura
Department of Hematology, Respiratory Medicine and Oncology, Division of Medicine, Saga University, Saga, Japan.
Yuki
Y
Nishida
Department of Hematology, Respiratory Medicine and Oncology, Division of Medicine, Saga University, Saga, Japan.
Shinya
S
Kimura
D000631:Aminopyridines / Q000494:pharmacology* / Q000627:therapeutic use; D017209:Apoptosis / Q000187:drug effects; D000069286:Bortezomib / Q000494:pharmacology; D045744:Cell Line, Tumor; D004151:Dipeptides / Q000494:pharmacology* / Q000627:therapeutic use; D004317:Doxorubicin / Q000494:pharmacology; D016158:Genes, p53 / Q000502:physiology; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D020522:Lymphoma, Mantle-Cell / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology; D010766:Phosphorylation; D010879:Piperazines / Q000494:pharmacology; D011379:Prognosis; D000071636:Protein Phosphatase 2C / Q000037:antagonists & inhibitors / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*
D000631:Aminopyridines; D004151:Dipeptides; C587624:GSK2830371; D007093:Imidazoles; D010879:Piperazines; C482205:nutlin 3; D000069286:Bortezomib; D004317:Doxorubicin; C000607458:PPM1D protein, human; D000071636:Protein Phosphatase 2C
MDM2; PPM1D; mantle cell lymphoma; p38 MAPK; p53