The Volume of Three-Dimensional Cultures of Cancer Cells In Vitro Influences Transcriptional Profile Differences and Similarities with Monolayer Cultures and Xenografted Tumors

Improving the congruity of preclinical models with cancer as it is manifested in humans is a potential way to mitigate the high attrition rate of new cancer therapies in the clinic. In this regard, three-dimensional (3D) tumor cultures in vitro have recently regained interest as they have been acclaimed to have higher similarity to tumors in vivo than to cells grown in monolayers (2D). To identify cancer functions that are active in 3D rather than in 2D cultures, we compared the transcriptional profiles (TPs) of two non-small cell lung carcinoma cell lines, NCI-H1650 and EBC-1 grown in both conditions to the TP of xenografted tumors. Because confluence, diameter or volume can hypothetically alter TPs, we made intra- and inter-culture comparisons using samples with defined dimensions. As projected by Ingenuity Pathway Analysis (IPA), a limited number of signal transduction pathways operational in vivo were better represented by 3D than by 2D cultures in vitro. Growth of 2D and 3D cultures as well as xenografts induced major changes in the TPs of these 3 modes of culturing. Alterations of transcriptional network activation that were predicted to evolve similarly during progression of 3D cultures and xenografts involved the following functions: hypoxia, proliferation, cell cycle progression, angiogenesis, cell adhesion, and interleukin activation. Direct comparison of TPs of 3D cultures and xenografts to monolayer cultures yielded up-regulation of networks involved in hypoxia, TGF and Wnt signaling as well as regulation of epithelial mesenchymal transition. Differences in TP of 2D and 3D cancer cell cultures are subject to progression of the cultures. The emulation of the predicted cell functions in vivo is therefore not only determined by the type of culture in vitro but also by the confluence or diameter of the 2D or 3D cultures, respectively. Consequently, the successful implementation of 3D models will require phenotypic characterization to verify the relevance of applying these models for drug development

Optimal Classes of Chemotherapeutic Agents Sensitized by Specific Small-Molecule Inhibitors of Akt In Vitro and In Vivo

Akt is a serine/threonine kinase that transduces survival signals from survival/growth factors. Deregulation and signal imbalance in cancer cells make them prone to apoptosis. Upregulation or activation of Akt to aid the survival of cancer cells is a common theme in human malignancies. We have developed small-molecule Akt inhibitors that are potent and specific. These Akt inhibitors can inhibit Akt activity and block phosphorylation by Akt on multiple downstream targets in cells. Synergy in apoptosis induction was observed when Akt inhibitors were combined with doxorubicin or camptothecin. Akt inhibitor–induced enhancement of topoisomerase inhibitor cytotoxicity was also evident in long-term cell survival assay. Synergy with paclitaxel in apoptosis induction was evident in cells pretreated with paclitaxel, and enhancement of tumor delay by paclitaxel was demonstrated through cotreatment with Akt inhibitor Compound A (A-443654). Combination with other classes of chemotherapeutic agents did not yield any enhancement of cytotoxicity. These findings provide important guidance in selecting appropriate classes of chemotherapeutic agents for combination with Akt inhibitors in cancer treatment

Expression Profile of BCL-2, BCL-X L , and MCL-1 Predicts Pharmacological Response to the BCL-2 Selective Antagonist Venetoclax in Multiple Myeloma Models

International audienceBCL-2 family proteins dictate survival of human multiple myeloma cells, making them attractive drug targets. Indeed, multiple myeloma cells are sensitive to antagonists that selectively target prosurvival proteins such as BCL-2/BCL-X L (ABT-737 and ABT-263/navitoclax) or BCL-2 only (ABT-199/GDC-0199/vene-toclax). Resistance to these three drugs is mediated by expression of MCL-1. However, given the selectivity profile of venetoclax it is unclear whether coexpression of BCL-X L also affects antitumor responses to venetoclax in multiple myeloma. In multiple mye-loma cell lines (n ¼ 21), BCL-2 is expressed but sensitivity to venetoclax correlated with high BCL-2 and low BCL-X L or MCL-1 expression. Multiple myeloma cells that coexpress BCL-2 and BCL-X L were resistant to venetoclax but sensitive to a BCL-X L – selective inhibitor (A-1155463). Multiple myeloma xenograft models that coexpressed BCL-X L or MCL-1 with BCL-2 were also resistant to venetoclax. Resistance to venetoclax was mitigated by cotreatment with bortezomib in xenografts that coex-pressed BCL-2 and MCL-1 due to upregulation of NOXA, a proapoptotic factor that neutralizes MCL-1. In contrast, xeno-grafts that expressed BCL-X L , MCL-1, and BCL-2 were more sensitive to the combination of bortezomib with a BCL-X L selective inhibitor (A-1331852) but not with venetoclax cotreatment when compared with monotherapies. IHC of multiple myeloma patient bone marrow biopsies and aspirates (n ¼ 95) revealed high levels of BCL-2 and BCL-X L in 62% and 43% of evaluable samples, respectively, while 34% were characterized as BCL-2 High /BCL-X L Low. In addition to MCL-1, our data suggest that BCL-X L may also be a potential resistance factor to venetoclax monotherapy and in combination with bortezomib. Mol Cancer Ther; 15(5); 1–13. Ó2016 AACR

Additional file 3: Figure S1. of Anti-c-Met monoclonal antibody ABT-700 breaks oncogene addiction in tumors with MET amplification

FISH images of tumor cells. These signals correspond to two target loci/centromere on chromosome homologues to which each of the fluorescent probes are bound: green, CEP7; and orange, MET. (PPT 799 kb

Additional file 4: Figure S2. of Anti-c-Met monoclonal antibody ABT-700 breaks oncogene addiction in tumors with MET amplification

IHC analysis of SNU5 tumors treated with ABT-700 in dose response for 21. (PPT 1098 kb

Discovery of a Potent and Selective BCL‑X_L Inhibitor with <i>in Vivo</i> Activity

A-1155463, a highly potent and selective BCL-X_L inhibitor, was discovered through nuclear magnetic resonance (NMR) fragment screening and structure-based design. This compound is substantially more potent against BCL-X_L-dependent cell lines relative to our recently reported inhibitor, WEHI-539, while possessing none of its inherent pharmaceutical liabilities. A-1155463 caused a mechanism-based and reversible thrombocytopenia in mice and inhibited H146 small cell lung cancer xenograft tumor growth <i>in vivo</i> following multiple doses. A-1155463 thus represents an excellent tool molecule for studying BCL-X_L biology as well as a productive lead structure for further optimization