Baicalein inhibits the proliferation and invasion of oral squamous cell carcinoma and its possible signaling pathway / 中国应用生理学杂志

OBJECTIVE@#To investigate the relationship between the anti-proliferation effect of baicalein and extracellular signal-regulated kinase and focal adhesion kinase(ERK-FAK) signal pathway in oral squamous cell carcinoma (OSCC).@*METHODS@#The study included two parts and each part contained 4 groups, including control, 20 μmol/L BAI, 40 μmol/L BAI, 80 μmol/L BAI or control, 40 μmol/L BAI, MEK inhibitor(0.33 nmol/L),MEK inhibitor(0.33 nmol/L)+40 μmol/L BAI.Each group was treated in triplicate for 24 hours and 48 hours.Cell counting kit-8 (CCK8) was used to detect the inhibitory effect of baicalein; Polymerase chain reaction(PCR) and Western blot were used to analysis the effect of Baicalein on E-cadherin and Vimentin. The expressions of extracellular signal-regulated kinase(ERK), phosphorylated (p-ERK), focal adhesion kinase (FAK) and phosphorylated focal adhesion kinase(p-FAK) were detected by Western blot. The regulatory effect of MEK inhibitor(U0126) on Baicalein was tested by Western blot assay.@*RESULTS@#The survival rate of cells treated with BAI is much lower than that of control group(<0.01); the mRNA and protein levels of E-cadherin were obviously higher than those of control group, while the mRNA and protein levels of Vimentin were lower than those of control group(<0.01).The protein levels of p-ERK and p-FAK treated with BAI were much lower than those of control group(<0.01), but the total ERK and FAK had no obvious changes (<0.05).The protein level of E-cadherin treated with MEK inhibitor was higher than that of control group(<0.01) and the protein levels of Vimentin, p-ERK and p-FAK were lower than those of control group (<0.01), while the total protein levels of ERK and FAK were the same(<0.05).@*CONCLUSIONS@#Baicalein can inhibit the proliferation and invasiveness of OSCC, which may be mediated by ERK-FAK signal pathway.

Mechanism Underlying NaF-Induced Apoptosis in Human Oral Squamous Cell Carcinoma

Few studies have evaluated the apoptosis-inducing efficacy of NaF on cancer cells in vitro but there has been no previous investigation of the apoptotic effects of NaF on human oral squamous cell carcinoma cells. In this study, we have investigated the mechanisms underlying the apoptotic response to NaF treatment in the YD9 human squamous cell carcinoma cell line. The viability of YD9 cells and their growth inhibition were assessed by MTT and clonogenic assays, respectively. Hoechst staining, DNA electrophoresis and TUNEL staining were conducted to detect apoptosis. YD9 cells were treated with NaF, and western blotting, immunocytochemistry, confocal microscopy, FACScan flow cytometry, and MMP and proteasome activity assays were performed sequentially. The NaF treatment resulted in a time- and dose-dependent decrease in YD9 cell viability, a dose-dependent inhibition of cell growth, and the induction of apoptotic cell death. The apoptotic response of these cells was manifested by nuclear condensation, DNA fragmentation, the reduction of MMP and proteasome activity, a decreased DNA content, the release of cytochrome c into the cytosol, the translocation of AIF and DFF40 (CAD) into the nucleus, a significant shift of the Bax/Bcl-2 ratio, and the activation of caspase-9, caspase-3, PARP, Lamin A/C and DFF45 (ICAD). Furthermore, NaF treatment resulted in the downregulation of G1 cell cyclerelated proteins, and upregulation of p53 and the Cdk inhibitor p27KIP1. Taken collectively, our present findings demonstrate that NaF strongly inhibits YD9 cell proliferation by modulating the expression of G1 cell cycle-related proteins and inducing apoptosis via mitochondrial and caspase pathways.

Mechanism Underlying NaF-Induced Apoptosis in Human Oral Squamous Cell Carcinoma

Few studies have evaluated the apoptosis-inducing efficacy of NaF on cancer cells in vitro but there has been no previous investigation of the apoptotic effects of NaF on human oral squamous cell carcinoma cells. In this study, we have investigated the mechanisms underlying the apoptotic response to NaF treatment in the YD9 human squamous cell carcinoma cell line. The viability of YD9 cells and their growth inhibition were assessed by MTT and clonogenic assays, respectively. Hoechst staining, DNA electrophoresis and TUNEL staining were conducted to detect apoptosis. YD9 cells were treated with NaF, and western blotting, immunocytochemistry, confocal microscopy, FACScan flow cytometry, and MMP and proteasome activity assays were performed sequentially. The NaF treatment resulted in a time- and dose-dependent decrease in YD9 cell viability, a dose-dependent inhibition of cell growth, and the induction of apoptotic cell death. The apoptotic response of these cells was manifested by nuclear condensation, DNA fragmentation, the reduction of MMP and proteasome activity, a decreased DNA content, the release of cytochrome c into the cytosol, the translocation of AIF and DFF40 (CAD) into the nucleus, a significant shift of the Bax/Bcl-2 ratio, and the activation of caspase-9, caspase-3, PARP, Lamin A/C and DFF45 (ICAD). Furthermore, NaF treatment resulted in the downregulation of G1 cell cyclerelated proteins, and upregulation of p53 and the Cdk inhibitor p27KIP1. Taken collectively, our present findings demonstrate that NaF strongly inhibits YD9 cell proliferation by modulating the expression of G1 cell cycle-related proteins and inducing apoptosis via mitochondrial and caspase pathways.