| Summary: | 碩士 === 輔仁大學 === 營養科學系碩士班 === 101 === According to our laboratory previous results, we have found that folate deficiency (FD) promoted invasion of human hepatocellular carcinoma (HCC) cells, which is mediated by aberrant activation of nuclear factor-κB (NF-κB) and Hedgehog (Hh) signaling pathway. However, it remains unclear that folate status modulated NF-κB and Hh signaling pathway by regulating levels of reactive oxygen species (ROS). The aim of this study was to investigate whether folate status modulates oxidative stress and cancer invasion-related signaling molecular mechanisms in Hep3B cells. In the model of oxidative stress, treating 10 mM hydrogen peroxide (H2O2) increased intracellular O2˙- level and cell death, FS could reduce H2O2 -induced O2˙- and cell death. After Hep3B cells were treated with 100μM H2O2, Sonic hedgehog (Shh) and Gli1 protein expression was increased and NF-κB protein expression was increased by promoting IκBα degradation. When Hep3B cells were treated with folate supplement (FS) or antioxidant (N-acetyl-L-cysteine, NAC), NF-κB and Shh protein expression were lower than H2O2 treating group. And oxidase inhibitor of diphenyleneiodonium chloride (DPI) increased NF-κB and IκBα protein expression. On the other hand, we found that FD increased intracellular H2O2 level and nuclear Gli1 protein expression, promoting IκBα degradation. Compared with FD group, treating the inhibitor of PI3K/Akt, NF-κB, Hh signaling (LY294002, BAY 11-7082, KAAD-cyclopamine) or antioxidant (NAC) did not affect Akt and p-Akt protein expression. However, blockade of PI3K/Akt and NF-κB signaling by LY294002 and BAY 11-7082 abrogted the p-IκBα protein expression. Treating the LY294002 and NAC decreased NF-κB protein expression. Treatment of inhibitor (LY294002, BAY 11-7082) and antioxidant (NAC) reversed the FD-induced nuclear Gli1 protein expression, but no any effect was observed in treatment of KAAD-cyclopamine or oxidase inhibitors (allopurinol, DPI and rotenone). In summary, folate status modulated intracellular ROS, FS reversed the low dose H2O2-induced NF-κB and Hh signaling pathway, and FD involved in regulating NF-κB and Hh signaling activation through ROS and PI3K/Akt pathway, but no any effect was observed in treatment of oxidase inhibitors in HCC cells.
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