CoPEC and chemotherapeutic drugs resistance
Colibactin-producing E. coli (CoPEC) increase colorectal tumor development in mice. Furthermore they also induce mutations which are found in patients' tumors. Here we investigated the impact of CoPEC on chemotherapeutic drugs resistance. For that we used in vitro models as well as in vivo (xenograft and AOM/DSS). We analyzed the expression of proteins known to be involved in drug resistance (proteins involved in epithelial mesenchymal transition as well as cancer stem cell). We found an up-regulation of those proteins after CoPEC infection. Data were validated in vivo. Together our results suggest that CoPEC might increase chemotherapeutic drugs resistance.
Steps to reproduce
All the experiments were performed using the CoPEC 11G5 strain. Human HT-29 cells were infected at a multiplicity of 500 in order to be sure that all the cells have been infected. To observe the growth of spheroids, we have to wait 2-3 weeks post-infection. Since 11G5 can invade cells, antibiotics must be added throughout the culture (gentamycin at 200µg/ml). For xenograft experiments (using nude mice), chemotherapy was applied 7 days post-engraftment. 5-FU was given twice a week (30 mg/kg of body weight). For preparation of conditioned media cells were cultured overnight in serum free medium. The next day medium was collected, centrifuged in order to remove any cells' fragments.