BEX2 is overexpressed in a subset of primary breast cancers and mediates nerve growth factor/nuclear factor-kappa B inhibition of apoptosis in breast cancer cell lines
CANCER RESEARCH
Authors: Naderi, Ali; Teschendorff, Andrew E.; Beigel, Juergen; Cariati, Massimiliano; Ellis, Ian O.; Brenton, James D.; Caldas, Carlos
Abstract
We have identified a novel subtype of estrogen receptor (ER)positive breast cancers with improved outcome after tamoxifen treatment and characterized by overexpression of the gene BEX2. BEX2 and its homologue BEX1 have highly correlated expression and are part of a cluster enriched for ER response and apoptosis genes. BEX2 expression is induced after estradiol (E2) treatment with a peak at 3 h, suggesting BEX2 is an estrogen-regulated gene. BEX2 belongs to a family of genes, including BEX1, NGFRAP1 (alias BEX3), BEXL1 (alias BEX4), and,NGFRAP1L1 (alias BEX5). Both BEX1 and NGFRAP1 interact with p75NTR and modulate nerve growth factor (NGF) signaling through nuclear factor-kappa B (NF-kappa B) to regulate cell cycle, apoptosis, and differentiation in neural tissues. In breast cancer cells, NGF inhibits C2-induced apoptosis through binding of p75NTR and NF-kappa B activation. Here, we show that BEX2 expression is necessary and sufficient for the NGF-mediated inhibition (through NF-kappa B activation) of C2-induced apoptosis. We also show that BEX2 modulates apoptosis of breast cancer cells in response to E2 (50 nmol/L) and tamoxifen (5 and 10 mu mol/L). Furthermore, BEX2 overexpression enhances the antiproliferative effect of tamoxifen at pharmacologic dose (1 mu mol/L). These data suggest that a NGF/BEX2/NF-kappa B pathway is involved in regulating apoptosis in breast cancer cells and in modulating response to tamoxifen in primary tumors.
Euphorbia tirucalli modulates gene expression in larynx squamous cell carcinoma
BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE
Authors: Franco-Salla, Gabriela Bueno; Prates, Janesly; Cardin, Laila Toniol; Dinarte dos Santos, Anemari Ramos; da Silva, Wilson Araujo, Jr.; da Cunha, Bianca Rodrigues; Tajara, Eloiza Helena; Oliani, Sonia Maria; Rodrigues-Lisoni, Flavia Cristina
Abstract
Background: Some plants had been used in the treatment of cancer and one of these has attracted scientific interest, the Euphorbia tirucalli (E. tirucalli), used in the treatment of asthma, ulcers, warts has active components with activities scientifically proven as antimutagenic, anti-inflammatory and anticancer. Methods: We evaluate the influence of the antitumoral fraction of the E. tirucalli latex in the larynx squamous cell carcinoma (Hep-2), on the morphology, cell proliferation and gene expression. The Hep-2 cells were cultivated in complete medium (MEM 10 %) and treated with E. tirucalli latex for 1, 3, 5 and 7 days. After statistically analyzing the proliferation of the tested cells, the cells were cultivated again for RNA extraction and the Rapid Subtractive Hybridization (RaSH) technique was used to identify genes with altered expression. The genes found using the RaSH technique were analyzed by Gene Ontology (GO) using Ingenuity Systems. Results: The five genes found to have differential expression were validated by real-time quantitative PCR. Though treatment with E. tirucalli latex did not change the cell morphology in comparison to control samples, but the cell growth was significantly decreased. The RaSH showed change in the expression of some genes, including ANXA1, TCEA1, NGFRAP1, ITPR1 and CD55, which are associated with inflammatory response, transcriptional regulation, apoptosis, calcium ion transport regulation and complement system, respectively. The E. tirucalli latex treatment down-regulated ITPR1 and up-regulated ANXA1 and CD55 genes, and was validated by real-time quantitative PCR. Conclusions: The data indicate the involvement of E. tirucalli latex in the altered expression of genes involved in tumorigenic processes, which could potentially be applied as a therapeutic indicator of larynx cancer.