Novel combination of @entity3840 and XXXX inhibitors in @entity1 @entity157 provides a synergistic increase in apoptosis.

@entity1 @entity8047 @entity5732 @entity1421 @entity1836 @entity1426 @entity9859 @entity157 @entity3840 @entity1366 @entity8228
@entity3840 ( @entity3840 ) and ERK-MAPK mitogenic signaling pathways are important in @entity1 @entity157 . We investigated the effect of @entity3840 inhibition on ERK-MAPK signaling and the effect of combining @entity8047 (MAPK kinase) and @entity3840 inhibitors in @entity1 @entity157 in vitro. COX and ERK expression were determined by immunoblot in HepG2 and Hep3B cells. @entity3840 and @entity8047 activity were determined by @entity1421 assay and phosphospecific immunoblot, respectively. Cell growth was determined by cell proliferation and cell counts. Apoptosis was determined by DNA fragmentation enzyme-linked immunosorbent assay and flow cytometry. Cell cycle was determined by flow cytometry. HepG2 and Hep3B cells do not express @entity9859 or @entity3840 . Correspondingly, basal and agonist ( @entity1426 , lipopolysaccharide)-stimulated @entity3840 activity is undetectable. Treatment of HepG2 and Hep3B cells with @entity8228 resulted in an increase in @entity1366 phosphorylation ( @entity8047 activity) in a concentration-dependent fashion ( @entity8228 , 1 to 100 micromol/L). Treatment with the @entity3840 inhibitor @entity8228 in the presence of @entity5732 ( @entity8047 inhibitor) effectively suppressed @entity1366 phosphorylation as determined by phosphospecific @entity1366 immunoblot. Total @entity1366 and @entity3840 were unchanged with @entity8228 and @entity5732 treatments. In HepG2 cells, @entity8228 (1 to 100 micromol/L) decreased apoptosis as determined by DNA fragmentation enzyme-linked immunosorbent assay. Relative apoptosis was increased with @entity5732 alone or in combination with @entity8228 (9 to 10 times the control value), eliminating the anti-apoptotic effect of @entity8228 . In Hep3B cells, apoptosis was unchanged with @entity8228 (1 to 50 micromol/L) or @entity5732 (1 to 10 micromol/L) alone. The combination of @entity8228 and @entity5732 in Hep3B cells resulted in a synergistic increase in apoptosis (10 times the control value). Relative apoptosis in both cell lines strongly correlated with changes in the expression of the antiapoptotic protein @entity1836 . Cellular growth was assessed by colorimetric proliferation assay and cell counts. HepG2 and Hep3B cells had concentration-dependent inhibition of cell growth with @entity8228 or @entity5732 treatment alone. The combination of @entity8228 and @entity5732 resulted in complementary inhibitory effects on growth. Growth inhibitory effects in HepG2 and Hep3B cells with combination treatment appear to be, in part, secondary to the induction of G(0)/G(1) and G(2)/M cell cycle arrest, respectively, as determined by flow cytometry. Despite differential signaling in HepG2 and Hep3B cells, the sum effect of combining the @entity3840 inhibitor @entity8228 and the @entity8047 inhibitor @entity5732 results in enhanced antitumor actions. This novel combination may be useful for in vivo studies of @entity157 .
