Fig. 5

PKCε depletion, as well as the inhibition of FGFR2c kinase activity counteract FGFR2 isoform switch-induced EMT. HaCaT cells were transfected with siRNA for ESRP1 or co-trasfected with with siRNA for ESRP1 and siRNA for PKCε. The transfection with unrelated siRNA (Cx siRNA) was used as control. Cells were then left untreated or stimulated with FGF2 in presence or absence of SU5402 as above. The densitometric analysis was performed as reported above. a Real-time RT-PCR shows that the decrease of FGFR2b expression and to the appearance of FGFR2c mRNA transcripts induced ESRP1 silencing is not affected by PKCε depletion or by the presence of SU5402. Results are expressed as mean value ± SE. Student’s t test was performed and significance levels were defined as p < 0.05. *p < 0.05, **p < 0.01. b, c Biochemical approaches show that ESRP1 and PKCε siRNA induces an efficient depletion of ESRP1 and PKCε protein levels (b). PKCε activation/phosphorylation (b), as well as E-cadherin downregulation and N-cadherin appearance (c), induced by ESRP1 depletion, are efficiently inhibited by both the depletion of PKCε or the treatment with SU5402. The densitometric analysis and Student t test were performed as reported above: *p < 0.05, ** p < 0.01, *** p < 0.001. d Real-time RT-PCR shows that the depletion of PKCε is sufficient to block the induction of the EMT-related transcription factors, evident in ESRP1-depleted cells in response to FGF2. Results are expressed as mean value ± SE. Student’s t test was performed as above. *p < 0.05, ** p < 0.01, *** p < 0.001