Fig. 5

Patient-derived primary epithelial tumor cells acquire chemo-resistance with elevated migration and invasive potentials upon repeated orbital shaking. a Heatmap represents relative expression levels of genes showing least twofold difference between breast cancer cells derived from chemotherapy-treated patients (CT-PC) and CT + sheer stress (SS) with a p value < 0.05 is shown. Red and green represent the highest and lowest value of each gene analyzed, respectively. Gene Ontology (GO) analysis of RNA sequencing data revealed differential molecular function and biological processes on CT + SS compared with CT-PCs. GO categories for genes using the Network Ontology Analysis program (http://www.pantherdb.org/). RNA seq analysis of CT-PCs and CT-PCs under orbital shaking (CT + SS) for 10 days revealed upregulation of multiple SS-induced genes; Epcam, Arg2, Cldn4, S100a14, Klf8, and Krt18 (b) and multi-drug resistance genes; Cxcr4, Aldh1, Abcg2, and Abcb5 (c) upon +SS (p value compared with the non-shaking control group). d Cell viability of CT-PCs and CT + SS following treatment with doxorubicin or paclitaxel for 24 h (p value compared with dimethyl sulfoxide (DMSO)-treated cells). e Migration analysis was performed on CT-PCs and CT + SS by measuring the number of migrating cells per field of the wound made in the monolayer of cells. The migrating or invasive cells were measured in triplicate. Statistically significant differences were tested at p < 0.05