Fig. 5: Re-expression of c-Raf reversed tumor suppressive effect of SCNN1B.

A The re-expression of wildtype c-Raf and mutant c-Raf (S29A, S259A) in DLD1-vector and DLD1-SCNN1B cells. B SCNN1B overexpression suppressed the protein expression of S259A mutant c-Raf. C Addition of MG132, but not chloroquine, rescued c-Raf S259A protein expression in SCNN1B-expressing DLD1 cells (left). SCNN1B increased the ubiquitination of c-Raf S259A, but had no effect of wildtype c-Raf (right). D Ectopic expression of wildtype or mutant c-Raf had no effects on growth of DLD1-vector cells. For SCNN1B-overexpressing cells, wildtype or S29A c-Raf rescued cell proliferation. E In DLD1 and F SW1116 cells, overexpression of wildtype or S29A c-Raf reversed the inhibitory effect of SCNN1B on colony formation, but c-Raf S259A had no effect. G Re-expression of wildtype c-Raf, but not c-Raf S259A, rescued c-Raf kinase activity in SCNN1B-overexpressing DLD1 cells. H SCNN1B overexpression increased 48h-IC50 values of 5-Fluorouracil. I SCNN1B overexpression promoted apoptosis induction by 5-Fluorouracil. Values represent meansā±āS.E.M.*Pā<ā0.05, **Pā<ā0.01, ***Pā<ā0.0001.