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Fisetin (3,3’,4’,7-tetrahydroxyflavone), a naturally occurring flavonoid, has been reported to inhibit proliferation and induce apoptosis in several cancer types. However, its effect on the anti-metastatic potential of cervical cancer cells remains unclear. In the present study, we found that fisetin inhibits the invasion and migration of cervical cancer cells. The expression and activity of urokinase plasminogen activator (uPA) was significantly suppressed by fisetin in a dose-dependent manner. We also demonstrated that fisetin reduces the phosphorylation of p38 MAPK, but not that of ERK1/2, JNK1/2, or AKT. Addition of a p38 MAPK inhibitor, SB203580, further enhanced the inhibitory effect of fisetin on the expression and activity of uPA and the invasion and motility in cervical cancer cells. Fisetin suppressed the TPA (tetradecanoylphorbol-13-acetate)-induced activation of p38 MAPK and uPA, and inhibited the TPA-enhanced migratory and invasive abilities. Furthermore, the promoter activity of the uPA gene was dramatically repressed by fisetin, which disrupted the nuclear translocation of NF-κB and its binding amount on the promoter of the uPA gene, and these suppressive effects could be further enhanced by SB203580. This study provides strong evidence for the molecular mechanism of fisetin in inhibiting the aggressive phenotypes by repression of uPA via interruption of p38 MAPK-dependent NF-κB signaling pathway in cervical cancer cells and thus contributes insight to the potential of using fisetin as a therapeutic strategy against cervical cancer by inhibiting migration and invasion.

Fisetin is a naturally occurring flavonoid that has been reported to inhibit the proliferation and to induce apoptotic cell death in several tumor cells. However, the apoptosis-inducing effect of fisetin on tumor cell lines was investigated besides HeLa cells. In this study, we found that fisetin induced apoptosis of HeLa cells in a dose- and time-dependent manner, as evidenced by nuclear staining of 4'-6-Diamidino-2-phenylindole (DAPI), flow cytometry assay, and Annexin-V/PI double-labeling. In addition, fisetin triggered the activations of caspases-3 and -8 and the cleavages of poly (ADP-ribose) polymerase, resulting in apoptosis induction. Moreover, treatment of HeLa cells with fisetin induced a sustained activation of the phosphorylation of ERK1/2, and inhibition of ERK1/2 by PD98059 (MEK1/2 inhibitor) or transfection with the mutant ERK1/2 expression vector significantly abolished the fisetin-induced apoptosis through the activation of caspase-8/-3 pathway. The in vivo xenograft mice experiments revealed that fisetin significantly reduced tumor growth in mice with HeLa tumor xenografts. In conclusion, our results indicated that fisetin exhibited anti-cancer effect and induced apoptosis in HeLa cell lines both in vitro and in vivo.

Abstract:In this study we investigate the molecular mechanisms of caspases and mitochondria in the extrinsic and intrinsic signal apoptosis pathways in human leukemia HL-60 cells after in vitro exposure to 18α-glycyrrhetinic acid (18α-GA). Cells were exposed to 18α-GA at various concentrations for various time periods and were harvested for flow cytometry total viable cell and apoptotic cell death measurements. Cells treated with 18α-GA significantly inhibited cell proliferation and induced cell apoptosis in a dose-dependent manner, with an IC 50 value of 100 µM at 48 h. The cell growth inhibition resulted in induction of apoptosis and decreased the mitochondria membrane potential (∆Ψ m ) and increased caspase-8, -9 and -3 activities. Furthermore, cytochrome c and AIF were released from mitochondria, as shown by western blotting and confirmed by confocal laser microscopy. Western blotting showed that 18α-GA increased the levels of pro-apoptotic proteins such as Bax and Bid and decreased the anti-apoptotic proteins such as Bcl-2 and Bcl-xl, furthermore, results also showed that 18α-GA increased Fas and Fas-L which are associated with surface death receptor in HL-60 cells. Based on those observations, the present study supports the hypothesis that 18α-GA-induced apoptosis in HL-60 cells involves the activation of the both extrinsic and intrinsic apoptotic pathways.

SLC7A11 overexpression might be a novel biomarker and a potential unfavorable prognostic factor as well as a potential therapeutic target for liver carcinoma.

Lapatinib, a novel oral dual tyrosine kinase inhibitor blocking HER1 and HER2 pathways, has presented beneficial effects on breast cancer with positive HER2. However, its efficacy is largely limited by the occurrence of acquired drug resistance. In this study, we aimed to explore the underlying molecular mechanisms of Lapatinib resistance using bioinformatics strategies. The gene expression profile of SKBR3-R (acquired Lapatinib-resistant) and SKBR3 (Lapatinib-sensitive) cell line was downloaded from gene expression omnibus database. Then, the differentially expressed genes (DEGs) were selected using dChip software. Furthermore, gene ontology (GO) and pathway enrichment analyses were carried out by using DAVID database. Finally, the protein-protein interaction network was constructed, and the hub genes in the network were analyzed by using STRING database. A total of 300 DEGs, such as HSPA5, MAP1LC3A and RASSF2, were screened out. GO functional enrichment analysis showed that the genes were associated with cell membrane component-related, stimulus-related and binding-related items. KEGG pathway analysis indicated that three dysfunctional pathways, including PPAR signaling pathway, cytokine-cytokine receptor interaction and pathways in cancer, were enriched. Protein-protein interaction network construction revealed that some hub genes, such as PPARG, TGFBI, TGFBR2, TIMP1, CTGF, UBA52 and JUN, might have an association with Lapatinib resistance. The present study offered new insights into the molecular mechanisms of Lapatinib resistance and identified a series of important hub genes that have the potential to be the targets for treatment of Lapatinib-resistant breast cancer.

In conclusion, the present study identified several hub genes, and cell cycle and metabolism-related pathways that may play critical roles in the tumorigenesis of liver cancer. Future validation laboratory experiments are required to confirm the results.

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