Transfection of miR-497 mimics and siRNA-RAF-1 both decreased levels of MEK1, ERK1, and p38 phosphorylation in HeLa cells, inhibited cell proliferation, migration and invasion, induced more cells arrested in the G0/G1 phase, and promoted cell apoptosis; while miR-497 inhibitors led to opposite results.
RAF-1 was knocked down in melanoma cells using siRNA transfection, and cell proliferation, migration and invasion were determined by the MTT, wound-healing and Transwell invasion assays, respectively.
Raf-1 kinase inhibitor protein (RKIP) plays a critical role in tumor development by regulating cell functions such as invasion, apoptosis and differentiation.
Raf-1 kinase inhibitor protein (RKIP) expression was associated with the onset, development, invasion, and metastasis of numerous tumor types including prostate cancer, melanoma, colorectal cancer, liver cancer, and breast cancer.
Now we present that (1) PKCvarepsilon physically interacts with Stat3alpha isoform in various human cancer cells: skin melanomas (MeWo and WM266-4), gliomas (T98G and MO59K), bladder (RT-4 and UM-UC-3), colon (Caco-2), lung (H1650), pancreatic (PANC-1), and breast (MCF-7 and MDA:MB-231); (2) inhibition of PKCvarepsilon expression using specific siRNA inhibits Stat3Ser727 phosphorylation, Stat3-DNA binding, Stat3-regulated gene expression as well as cell invasion; and (3) PKCvarepsilon mediates Stat3Ser727 phosphorylation through integration with the MAPK cascade (RAF-1, MEK1/2, and ERK1/2).
In the FTC-133 cell line, geldanamycin treatment decreased clonogenicity by 21% at a concentration of 50 nM; geldanamycin induced apoptosis and down-regulated c-Raf-1, mutant p53, and epidermal growth factor (EGF) receptor expression; geldanamycin inhibited EGF-stimulated invasion.