Figure 4

Induction of interferon response in two types of breast cancer cell lines. (a) MDA-MB231 cells were incubated in conditioned media from CCL-171 monoculture, MDA-MB231 monoculture, T47D monoculture, CCL-171/MDA-MB231 co-culture and CCL-171/T47D co-culture. OAS2 gene expression was determined by quantitative RT-PCR. The gene expression level of GAPDH was used for normalization between the samples. A strong induction of OAS2 by the supernatant from the CCL-171/MDA-MB231 co-culture can be seen in MDA-MB231. (b) Incubation of T47D cells with conditioned media from CCL-171 monoculture, MDA-MB231 monoculture, T47D monoculture, CCL-171/MDA-MB231 co-culture and CCL-171/T47D co-culture showed that only the CCL-171/MDA-MB231 co-culture supernatant induced OAS2 gene expression, although to a much lesser extent than in MDA-MB231 cells. (c) Gene expression levels of IFNβ were determined by quantitative RT-PCR. CCL-171 cells show much higher IFNβ expression levels when isolated by FACS after co-culture with MDA-MB231 than with T47D cells. Expression levels in tumor cells are shown as controls. The error bars show the standard deviation from the normalized mean.