Influence of substrate stiffness on chemotherapeutic response in breast cancer

Mechanical feedback from the tumor microenvironment regulates an array of processes underlying cancer biology. Routine culture and adaptation of cancer cell lines to unnaturally rigid plastic or glass substrates leads to profound changes in their growth, metastatic potential and potentially chemotherapeutic response. Microarray studies were conducted to probe the impact of substratum stiffness on the regulation of genetic pathways in mammary tumor cells, and immortalized cancer cell lines, that modulate sensitivity and resistance towards clinically-approved chemotherapeutics We used microarrays to detail the global programme of gene expression underlying cellular response to substrates of different mechanical stiffness. mammary tumor cells, isolated from FVB/N-Tg(MMTV-PyVT)634Mul/J transgenic mice (referred to as MMTV-PyVT), or an immortalized human breast cancer cell line (MDA-MB-453) were seeded onto fibronectin-coated polyacrylamide gels of 5 and 30 kPa stiffness, or glass as a control. After 5 days of culture, cellular RNA was extracted from cells seeded onto gels of varying stiffness in the array and utilized for hybridization on Affymetrix mouse or human gene microarrays. Four replicates from each condition were analyzed, and data referenced against cells seeded onto glass as controls. Array data were processed using the affy and limma bioconductor packages.