midostaurin and Pancreatic-Neoplasms

PKC412 is a kinase inhibitor that blocks protein kinase C (PKC), vascular endothelial growth factor receptors, platelet-derived growth factor receptor FLT3, and other class III receptor tyrosine kinases. The enthusiasm for this compound is based on its inhibitory effect even in the case of FLT3 mutations. The aim of this study was to analyze the role of FLT3 in pancreatic cancer and to study the biological activity of combined inhibition of neovascularization and mitogenesis in this disease.. FLT3 expression was analyzed in 18 pancreatic cancer specimens by real-time quantitative polymerase chain reaction (RTQ-PCR) and immunohistochemistry. Sixteen pancreatic cancer cell lines were screened for ITD and D835 point mutations of the FLT3 gene. MTT assays and anchorage-independent growth assays were used to study cell growth. Flow cytometry was used for cell cycle analysis and apoptosis quantification. In vivo AsPC-1 and HPAF-II cells were used for orthotopic tumor modeling. Immunohistochemistry was used to quantify tumor angiogenesis.. FLT3 expression is down-regulated in pancreatic cancer. Activating FLT3 mutations (ITD, D835) were not detectable in any of the pancreatic cancer cell lines. Cell growth was significantly inhibited as cell-cycle progression was reduced and programmed cell death increased. In vivo PKC412 therapy resulted in a significant inhibition of orthotopic tumor growth with abrogation of tumor angiogenesis.. These data highlight that PKC412 may be a new compound in target therapy of inoperable pancreatic cancer patients and suggest a potential role for the combined use of broad spectrum kinase inhibitors in the management of these patients.

Topics: Adenocarcinoma; Angiogenesis Inhibitors; Animals; Antineoplastic Agents; Apoptosis; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Down-Regulation; Flow Cytometry; fms-Like Tyrosine Kinase 3; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Male; Mice; Mice, Inbred BALB C; Microcirculation; Pancreatic Neoplasms; Point Mutation; Polymerase Chain Reaction; Protein Kinase C; Receptors, Vascular Endothelial Growth Factor; Sequence Analysis, DNA; Signal Transduction; Staurosporine; Tandem Repeat Sequences; Tumor Cells, Cultured

We have previously found that the staurosporine derivative, CGP 41 251, that has a high specificity for inhibiting protein kinase C (PKC), selectively blocks oncogenic ras-p21-induced oocyte maturation and that PKC and jun-N-terminal kinase (JNK), with which oncogenic ras-p21 directly interacts, reciprocally require each other's activation. We sought to determine whether CGP 41 251 blocks proliferation of ras-transformed mammalian cells and whether it synergistically exerts this effect with a ras-p21 peptide (residues 96-110) that interferes with the interaction of ras-p21 with JNK.. We incubated ras-transformed rat pancreatic cancer TUC-3 cells and their normal counterpart pancreatic acinar BMRPA1 cells with CGP 42 251 alone and in the presence of the ras-p21 96-110 peptide, both in pre- and post-monolayer phases and determined cell counts and morphology and, for TUC-3 cells, their ability to grow on soft agar. In the post-monolayer experiments, we also evaluated these parameters after withdrawal of these agents.. CGP 41 251, but not its inactive analogue, CGP 42 700, blocked pre-monolayer growth and reduced post-monolayer cell counts of both TUC-3 and BMRPA1 cells (IC(50) 0.28 and 0.35 micro M, respectively). After 2 weeks of treatment, all the remaining TUC-3 cells exhibited the untransformed phenotype. Withdrawal of CGP 41 251 resulted in almost complete regrowth of the normal BMRPA1 cells while the reverted TUC-3 cells grew much more slowly. These effects were greatly enhanced by the presence of the ras-p21 96-110 peptide.. CGP 41 251 strongly blocks growth of ras-transformed pancreatic cancer cells by causing cell death and by induction of phenotypic reversion. The enhancement of this effect by the ras-p21 96-110 peptide indicated synergy between it and CGP 41 251, allowing it to block proliferation of the transformed cells selectively. These findings suggest the possibility of using these two agents in anticancer therapy.

Topics: Antineoplastic Agents; Carcinoma, Acinar Cell; Cell Division; Cell Transformation, Neoplastic; Cells, Cultured; Enzyme Inhibitors; Humans; JNK Mitogen-Activated Protein Kinases; Mitogen-Activated Protein Kinases; Oncogene Protein p21(ras); Pancreatic Neoplasms; Peptide Fragments; Phenotype; Protein Binding; Protein Kinase C; Signal Transduction; Staurosporine