1 Flavonoids display a wide range of pharmacological properties including anti-in¯ammatory. Anti-mutagenic, anti-carcinogenic and anti-cancer eects. Here, we evaluated the eects of eight avonoids on the tumour cell proliferation, cellular protein phosphorylation, and matrix metalloproteinase (MMPs) secretion. 2 Of the¯avonoids examined, luteolin (Lu) and quercetin (Qu) were the two most potent agents, and signi®cantly inhibited A431 cell proliferation with IC 50 values of 19 and 21 mM, respectively. 3 The epidermal growth factor (EGF) (10 nM) promoted growth of A431 cells (+25+4.6%) and mediated epidermal growth factor receptor (EGFR) tyrosine kinase activity and autophosphorylation of EGFR were inhibited by Lu and Qu. At concentration of 20 mM, both Lu and Qu markedly decreased the levels of phosphorylation of A431 cellular proteins, including EGFR. 4 A431 cells treated with Lu or Qu exhibited protuberant cytoplasmic blebs and progressive shrinkage morphology. Lu and Qu also time-dependently induced the appearance of a ladder pattern of DNA fragmentation, and this eect was abolished by EGF treatment. 5 The addition of EGF only marginally diminished the inhibitory eect of luteolin and quercetin on the growth rate of A431 cells, treatment of cellular proteins with EGF and luteolin or quercetin greatly reduced protein phosphorylation, indicating Lu and Qu may act eectively to inhibit a wide range of protein kinases, including EGFR tyrosine kinase. 6 EGF increased the levels of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9), while Lu and Qu appeared to suppress the secretion of these two MMPs in A431 cells. 7 Examination of the relationship between the chemical structure and inhibitory eects of eight avonoids reveal that the double bond between C2 and C3 in ring C and the OH groups on C3' and C4' in ring B are critical for the biological activities. 8 This study demonstrates that the inhibitory eects of Lu and Qu, and the stimulatory eects of EGF, on tumour cell proliferation, cellular protein phosphorylation, and MMP secretion may be mediated at least partly through EGFR. This study supports the idea that Lu and Qu may have potential as anti-cancer and anti-metastasis agents.

Transforming growth factor (TGF)b1 facilitates FSH-induced differentiation of rat ovarian granulosa cells. The signaling crosstalk between follicle stimulating hormone (FSH) and TGFb receptors remains unclear. This study was to investigate the interplay of cAMP/protein kinase A (PKA) and phosphatidylinositol-3-kinase (PI3K) signaling including mammalian target of rapamycin (mTOR)C1 dependence in FSH-and TGFb1-stimulated steroidogenesis in rat granulosa cells. To achieve this aim, inhibitors of PKA (PKAI), PI3K (wortmannin), and mTORC1 (rapamycin) were employed. PKAI and wortmannin suppressions of the FSH-increased progesterone production were partly attributed to decreased level of 3b-HSD, and their suppression of the FSH plus TGFb1 effect was attributed to the reduction of all the three key players, steroidogenic acute regulatory (StAR) protein, P450scc, and 3b-HSD. Further, FSH activated the PI3K pathway including increased integrin-linked kinase (ILK) activity and phosphorylation of Akt(S473), mTOR(S2481), S6K(T389), and transcription factors particularly FoxO1(S256) and FoxO3a(S253), which were reduced by wortmannin treatment but not by PKAI. Interestingly, PKAI suppression of FSH-induced phosphorylation of cAMP regulatory element-binding protein (CREB(S133)) disappeared in the presence of wortmannin, suggesting that wortmannin may affect intracellular compartmentalization of signaling molecule(s).In addition, TGFb1 had no effect on FSH-activated CREB and PI3K signaling mediators. We further found that rapamycin reduced the TGFb1-enhancing effect of FSH-stimulated steroidogenesis, yet it exhibited no effect on FSH action. Surprisingly, rapamycin displayed a suppressive effect at concentrations that had no effect on mTORC1 activity. Together, this study demonstrates a delicate interplay between cAMP/PKA and PI3K signaling in FSH and TGFb1 regulation of steroidogenesis in rat granulosa cells. Furthermore, we demonstrate for the first time that TGFb1 acts in a rapamycinhypersensitive and mTORC1-independent manner in augmenting FSH-stimulated steroidogenesis in rat granulosa cells.

Chronic inflammation can augment tumor development in various types of cancers, including prostate cancer (PCa). Reduction of inflammation is therefore an important anticancer therapeutic opportunity. Here, we report four anti-proliferative phytocompounds in Wedelia chinensis, an oriental herbal medicine, identified through their ability to modulate the androgen receptor (AR) activation of transcription from prostate-specific antigen promoter in PCa cells. The 50% inhibition concentration values of indole-3-carboxylaldehyde, wedelolactone, luteolin and apigenin, were 34.9, 0.2, 2.4 and 9.8 muM, respectively. A formula that combined the phytocompounds in the same proportions as in the herbal extract decreased the dosage of each compound required to achieve maximal AR inhibition. In correlation with the AR suppression effect, these active compounds specifically inhibited the growth of AR-dependent PCa cells and as a combination formula they also synergistically suppressed growth in AR-dependent PCa cells. Our study has identified synergistic effects of active compounds in W. chinensis and demonstrated their potential in PCa prevention and therapy. The paradigm of multiple activities and synergism is a useful framework to investigate the therapeutic effects of whole extracts from assorted medicinal plant species.

Highly invasive A431-III cells, which are derived from parental A431-P cells, were originally isolated by three successive passages through a Boyden chamber using a Matrigel-coated membrane support. The greater invasion potential shown by A431-III cells was due to their increased ability to spread ⁄ migrate, which was associated with enhanced MMP activity. The tumor progression events evoked by A431-P cells compared to A431-III cells may help identify useful strategies for evaluating the epithelial-mesenchymal transition (EMT) and these cell lines could be a reliable model for evaluating tumor metastasis events. Using this approach, we evaluated the effects of luteolin and quercetin using the A431-P ⁄ A431-III EMT model. These flavonoids reversed cadherin switching, downregulated EMT markers, and nullified the invasion ability of A431-III cells. Overexpression of MMP-9 resulted in induction of the EMT in A431-P cells and this could be reversed by treating with luteolin or quercetin. Cotreatment of A431-P and A431-III cells with epidermal growth factor (EGF) plus luteolin or quercetin resulted in a more epithelial-like morphology, led to reduced levels of EGF-induced markers of EMT, and caused the restoration of cell-cell junctions. Ecadherin was decreased by EGF, but increased by luteolin and quercetin. Our results suggest that luteolin and quercetin are potentially beneficial agents that target and prevent the occurrence of EMT in epidermal carcinoma cells. These chemicals also have the ability to attenuate tumor progression in A431-III cells. Luteolin and quercetin show inherent potential as chemopreventive ⁄ antineoplastic agents and do this by abating tumor progression through a reversal of

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