mk-2206 and trametinib

Standard chemotherapy for pancreatic ductal adenocarcinoma (PDAC), nab-paclitaxel (NPT) plus gemcitabine (Gem), has led to an average survival of 8.5 months. Presently, no therapeutics exist that effectively target the KRAS oncogene, activated in 95% of PDACs, but alternative strategies focus on inhibition of downstream effectors of KRAS signaling. Through combined inhibition of PI3K and MAPK signaling with MK-2206 (MK) and trametinib (Tra), enhancement of NPT + Gem response was evaluated. Median animal survival was significantly improved by the NPT + Gem combination (67% increase). Addition of MK-2206 or trametinib further increased median survival: NPT + Gem + MK (86%), NPT + Gem + Tra (105%), and NPT + Gem + MK + Tra (129%). In cell line-derived xenografts, the net tumor growth (in mm

Topics: Albumins; Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Carcinoma, Pancreatic Ductal; Cell Line, Tumor; Cell Proliferation; Deoxycytidine; Drug Synergism; Female; Gemcitabine; Heterocyclic Compounds, 3-Ring; Humans; MAP Kinase Signaling System; Mice; Mice, Inbred NOD; Mice, SCID; Paclitaxel; Pancreatic Neoplasms; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Pyridones; Pyrimidinones; Xenograft Model Antitumor Assays

Cells grown in three-dimensional (3D) cultures are more likely to have native cell-cell and cell-matrix interactions than in 2D cultures that impose mechanical constraints to cells. However, most 3D cultures utilise gel matrix which, while serving as a scaffold, limits application due to its solid and opaque nature and inconsistency in cell exposure to exogenous signals. In 3D culture without gel matrix, cells tend to adhere to each other and form clumps with necrotic zone at the centre, making them unsuitable for analyses. Here we report that addition of low-molecular-weight agar named LA717 to culture media allows cells to grow as dispersed clonal spheroids in 3D. LA717 maintains cells dispersed and settled to the bottom of the medium while keeping the medium clear with little additional viscosity, making it suitable for microscopic observation. Importantly, cancer spheroids formed in LA717-containing medium show higher sensitivity to anti-cancer drugs such as Trametinib and MK-2206 that are not as effective in 2D. Because of the small and consistent size of spheroids, cell viability and drug toxicity are readily detectable in automated imaging analysis. These results demonstrate that LA717 offers a novel 3D culture system with great in vivo reflection and practicality.

Topics: A549 Cells; Antineoplastic Agents; Apoptosis; Cell Culture Techniques; Cell Line, Tumor; Cell Proliferation; Cell Survival; Drug Evaluation, Preclinical; HCT116 Cells; HeLa Cells; Hep G2 Cells; Heterocyclic Compounds, 3-Ring; Humans; Pyridones; Pyrimidinones; Real-Time Polymerase Chain Reaction; Spheroids, Cellular

Topics: Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Pancreatic Ductal; Cell Growth Processes; Drug Synergism; Heterocyclic Compounds, 3-Ring; Humans; MAP Kinase Kinase Kinases; Morpholines; Pancreatic Neoplasms; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Protein Kinase Inhibitors; Pyridones; Pyrimidinones; Triazines

Pancreatic ductal adenocarcinoma (PDAC) is a highly deadly malignancy. Expression of the stem cell transcription factor SOX2 increases during progression of PDAC. Knockdown of SOX2 in PDAC cell lines decreases growth in vitro; whereas, stable overexpression of SOX2 in one PDAC cell line reportedly increases growth in vitro. Here, we reexamined the role of SOX2 in PDAC cells, because inducible SOX2 overexpression in other tumor cell types inhibits growth. In this study, four PDAC cell lines were engineered for inducible overexpression of SOX2 or inducible knockdown of SOX2. Remarkably, inducible overexpression of SOX2 in PDAC cells inhibits growth in vitro and reduces tumorigenicity. Additionally, inducible knockdown of SOX2 in PDAC cells reduces growth in vitro and in vivo. Thus, growth and tumorigenicity of PDAC cells is highly dependent on the expression of optimal levels of SOX2 - a hallmark of molecular rheostats. We also determined that SOX2 alters the responses of PDAC cells to drugs used in PDAC clinical trials. Increasing SOX2 reduces growth inhibition mediated by MEK and AKT inhibitors; whereas knockdown of SOX2 further reduces growth when PDAC cells are treated with these inhibitors. Thus, targeting SOX2, or its mode of action, could improve the treatment of PDAC.

Topics: Adenocarcinoma; Animals; Antineoplastic Agents; Carcinoma, Pancreatic Ductal; Cell Line, Tumor; Cell Proliferation; Doxorubicin; Female; Heterocyclic Compounds, 3-Ring; Humans; Mice; Mice, Nude; Mitogen-Activated Protein Kinase Kinases; Pancreatic Neoplasms; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins p21(ras); Pyridones; Pyrimidinones; RNA Interference; RNA, Small Interfering; SOXB1 Transcription Factors