Oct-4 is required for an antiapoptotic behavior of chemoresistant colorectal cancer cells enriched for cancer stem cells: effects associated with STAT3/Survivin.

Cancer stem cells (CSCs) have been implicated in multidrug resistance, a phenomenon responsible for the failure of cancer chemotherapy. However, the underlying mechanisms are still unclear. In our study, we established two oxaliplatin-resistant colorectal cancer cell lines displaying some CSCs characteristics. Oct4 overexpression was observed in these two lines. We performed Oct4 knock down by lentiviral vector-mediated specific shRNA. Knockdown increased apoptosis, decreased CSCs marker expression and weakened tumorigenicity in drug-resistant cell lines. In conclusion, we show that these events can be at least in part attributed to the STAT3/Survivin pathway.