Extracellular Matrix Environment and Chemotherapeutics

We report that the efficacy of a Raf kinase inhibitor, sorafenib, is reduced on stiff, collagen-rich microenvironments, independent of ROCK activity. Instead, sustained activation of JNK mediated this resistance, and combining a JNK inhibitor with sorafenib eliminated stiffness-mediated resistance in triple negative breast cancer cells. Surprisingly, neither ERK nor p38 appears to mediate sorafenib resistance, and instead, either ERK or p38 inhibition rescued sorafenib resistance during JNK inhibition, suggesting negative crosstalk between these signaling pathways on stiff, collagen-rich environments. Overall, we discovered that β1 integrin and its downstream effector JNK mediate sorafenib resistance during tumor stiffening. These results also highlight the need for more advanced cell culture platforms, such as our high-throughput PEG-PC system, with which to screen chemotherapeutics.Figure: High-throughput biomaterial platform for drug screening. (A) The high-throughput platform consists of a black-walled, glass bottom plate, with PEG-PC gels cast in each of the inner 6x10 wells. (B) Gels can be functionalized with any protein or peptide of interest, and they support the adhesion and growth of carcinoma cells. We used this platform to test carcinoma cell response to a kinase inhibitor (sorafenib) as a function of underlying gel stiffness and ECM adhesive protein cocktail. (C) A representative graph of SkBr3 proliferation (y-axis) in response to sorafenib (x-axis) across a r...
Source: Neuromics - Category: Neuroscience Tags: 3-D Cell based Assays 3-D Cell Culturing chemotherapies chemotherapy Collagen Drug Discovery Extracellular Matrix Highthroughput Screening Source Type: news