HGF-Induced PKCζ Activation Increases Functional CXCR4 Expression in Human Breast Cancer Cells

The chemokine receptor CXCR4 and its ligand CXCL12 have been shown to mediate the metastasis of many malignant tumors including breast carcinoma. Interaction between hepatocyte growth factor (HGF) and the Met receptor tyrosine kinase mediates development and progression of cancers. HGF is able to induce CXCR4 expression and contributes to tumor cell invasiveness in breast carcinoma. However, the mechanism of the CXCR4 expression modulated by c-Met-HGF axis to enhance the metastatic behavior of breast cancer cells is still unclear. In this study, we found that HGF induced functional CXCR4 receptor expression in breast cancer cells. The effect of HGF was specifically mediated by PKCζ activity. After transfection with PKCζ-siRNA, the phosphorylation of PKCζ and CXCR4 was abrogated in breast cancer cells. Interference with the activation of Rac1, a downstream target of HGF, prevented the HGF-induced increase in PKCζ activity and CXCR4 levels. The HGF-induced, LY294002-sensitive translocation of PKCζ from cytosol to plasma membrane indicated that HGF was capable of activating PKCζ, probably via phosphoinositide (PI) 3-kinases. HGF treatment also increased MT1-MMP secretion. Inhibition of PKCζ, Rac-1 and phosphatidylinositol 3-kinase may attenuate MT1-MMP expression in cells exposed to HGF. Functional manifestation of the effects of HGF revealed an increased ability for migration, chemotaxis and metastasis in MDA-MB-436 cells in vitro and in vivo. Our findings thus provided evidence that the process of HGF-induced functional CXCR4 expression may involve PI 3-kinase and atypical PKCζ. Moreover, HGF may promote the invasiveness and metastasis of breast tumor xenografts in BALB/c-nu mice via the PKCζ-mediated pathway, while suppression of PKCζ by RNA interference may abrogate cancer cell spreading

Tuscany Sangiovese Grape juice imparts cardioprotection by regulating gene expression of Cardioprotective C-Type Natriuretic Peptide.

Purpose: A regular intake of red grape juice has cardioprotective properties, but its role on the modulation of natriuretic peptides (NPs), in particular of C-type NP (CNP), has not yet been proven. The aims were to evaluate: 1) in vivo the effects of long-term intake of Tuscany Sangiovese grape juice (SGJ) on the NPs system in a mouse model of MI; 2) in vitro the response to SGJ small RNAs of murine MCEC-1 under physiological and ischemic condition; 3) the activation of the CNP/NPR-B/NPR-C in healthy human subjects after 7 days’ SGJ regular intake. Methods: 1) C57BL/6J male and female mice (n=33) were randomly subdivided into: Sham (n=7), MI (n=15) and MI fed for 4 weeks with a normal chow supplemented with Tuscany SGJ (25% vol/vol, 200 µl/die) (MI+SGJ, n=11). Echocardiography and histological analyses were performed. Myocardial NPs transcriptional profile was investigated by Real-Time PCR. 2) MCEC-1 were treated for 24h with a pool of SGJ small RNAs and cell viability under 24h exposure to H2O2 was evaluated by MTT assay. 3) Human blood samples were collected from 7 subjects before and after the 7 days’ intake of Tuscany SGJ. NPs and miRNA transcriptional profile were investigated by Real-Time PCR in MCEC-1 and human blood. Results: We found that regular diet supplementation with SGJ rich of miRNAs promotes protection of ischemic heart against myocardial infarction in male rather than female mice through the induction of myocardial CNP/NPR-B/NPR-C system. In vitro, SGJ-derived miRNAs preserved endothelial cell viability under oxidative stress. In human subjects fed with SGJ, the maintenance of circulating grape microRNAs levels was related to higher plasma levels of CNP mRNA and subsequent counter-regulation of NPR-B gene expression. Conclusions: Our experimental data obtained in a multimodal translational pipeline open new avenue in the development of functional foods aimed at enhancing cardioprotection of infarcted hearts through action on the myocardial epigenome

Sex Hormone Receptors in Vocal Fold Tissue: A Theory about the Influence of Sex Hormones in the Larynx

OBJECTIVE: The larynx is considered a secondary sexual organ. To demonstrate that sex hormones can directly influence laryngeal function, specific receptors in the vocal cord must be identified. MATERIALS AND METHODS: We searched for estrogen, progesterone and androgen receptors, using an immunohistochemical method, in normal human vocal cords (from 3 cadavers) and in samples of healthy vocal cords and of laryngeal carcinomas from 15 live subjects. Breast and prostate carcinoma were used as controls. RESULTS: In all the normal samples tested, the results were negative; there was only a nonspecific cytoplasmatic response in the subepithelial glands (false positives). In the neoplastic tissue, 2 samples had a weak nuclear focal positivity for estrogen and progesterone receptors; all 15 subjects studied were negative for androgen receptors. CONCLUSIONS: Since our data show that sex hormone receptors are absent in the vocal cords, other theories must be considered to explain the fact that hormones influence the quality of the voice. This study discusses the possibility that the changes of voice according to gender and throughout life might be linked with a different expression of some growth factors in the laryngeal tissue and that this expression might in turn be influenced by hormonal variations