title: Targeting protein kinase C in mantle cell lymphoma.
abstract: Although targeting the Bruton tyrosine kinase (BTK) with ibrutinib has changed lymphoma treatment, patients with mantle cell lymphoma (MCL) remain incurable. In this study, we characterized a broad range of MCL cell lines and primary MCL cells with respect to the response to the BTK inhibitor, ibrutinib, and compared it with the response to the protein kinase C (PKC) inhibitor, sotrastaurin. At clinically relevant concentrations, each drug induced potent cell death only in the REC-1 cell line, which was accompanied by robust inhibition of AKT and ERK1/ERK2 (ERK1/2, also termed MAPK3/MAPK1) phosphorylation. In sensitive REC-1 cells, the drug-mediated impaired phosphorylation was obvious on the levels of B-cell receptor-induced and basal phosphorylation. Similar results were obtained in primary MCL cells with ibrutinib and in a subset with sotrastaurin. The various drug-resistant MCL cell lines showed very distinct responses in terms of basal AKT and ERK1/2 phosphorylation. Interestingly, targeting PKC and BTK at the same time led to ibrutinib-mediated rescue of a weak sotrastaurin-induced apoptosis in MINO cells. Additional targeting of AKT sensitized MINO cells to inhibitor-mediated cytotoxicity. In summary, MCL cells are heterogeneous in their response to BTK or PKC inhibition, indicating the need for even more individualized targeted treatment approaches in subsets of MCL patients.
authors.affiliation: Institute of Pathology, University of Würzburg and Comprehensive Cancer Center (CCC) Mainfranken, Würzburg, Germany.
authors.forename: Hilka
authors.initials: H
authors.lastname: Rauert-Wunderlich
authors.affiliation: Institute of Pathology, University of Würzburg and Comprehensive Cancer Center (CCC) Mainfranken, Würzburg, Germany.
authors.forename: Martina
authors.initials: M
authors.lastname: Rudelius
authors.affiliation: Department of Clinical Pathology, Robert-Bosch-Krankenhaus, Stuttgart, Germany.|Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology, Stuttgart, Germany.
authors.forename: German
authors.initials: G
authors.lastname: Ott
authors.affiliation: Institute of Pathology, University of Würzburg and Comprehensive Cancer Center (CCC) Mainfranken, Würzburg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Rosenwald
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives; D000077329:Agammaglobulinaemia Tyrosine Kinase; D000970:Antineoplastic Agents / Q000494:pharmacology; D016923:Cell Death / Q000187:drug effects; D019008:Drug Resistance, Neoplasm / Q000187:drug effects; D006801:Humans; D020522:Lymphoma, Mantle-Cell / Q000188:drug therapy*; D020935:MAP Kinase Signaling System / Q000187:drug effects; D058990:Molecular Targeted Therapy / Q000379:methods*; D010766:Phosphorylation; D010880:Piperidines; D011493:Protein Kinase C / Q000037:antagonists & inhibitors*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D011720:Pyrazoles / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology; D011758:Pyrroles / Q000494:pharmacology; D011799:Quinazolines / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D010880:Piperidines; D047428:Protein Kinase Inhibitors; D011720:Pyrazoles; D011743:Pyrimidines; D011758:Pyrroles; D011799:Quinazolines; C551803:ibrutinib; C543528:sotrastaurin; D011505:Protein-Tyrosine Kinases; D000077329:Agammaglobulinaemia Tyrosine Kinase; C000625949:BTK protein, human; D011493:Protein Kinase C; D000225:Adenine
keywords: B-cell receptor signalling; Bruton tyrosine kinase; ibrutinib; mantle cell lymphoma; sotrastaurin