Dataset Information

Non-stimulated, agonist-stimulated and store-operated Ca2+ influx in MDA-MB-468 breast cancer cells and the effect of EGF-induced EMT on calcium entry.

ABSTRACT: In addition to their well-defined roles in replenishing depleted endoplasmic reticulum (ER) Ca(2+) reserves, molecular components of the store-operated Ca(2+) entry pathway regulate breast cancer metastasis. A process implicated in cancer metastasis that describes the conversion to a more invasive phenotype is epithelial-mesenchymal transition (EMT). In this study we show that EGF-induced EMT in MDA-MB-468 breast cancer cells is associated with a reduction in agonist-stimulated and store-operated Ca(2+) influx, and that MDA-MB-468 cells prior to EMT induction have a high level of non-stimulated Ca(2+) influx. The potential roles for specific Ca(2+) channels in these pathways were assessed by siRNA-mediated silencing of ORAI1 and transient receptor potential canonical type 1 (TRPC1) channels in MDA-MB-468 breast cancer cells. Non-stimulated, agonist-stimulated and store-operated Ca(2+) influx were significantly inhibited with ORAI1 silencing. TRPC1 knockdown attenuated non-stimulated Ca(2+) influx in a manner dependent on Ca(2+) influx via ORAI1. TRPC1 silencing was also associated with reduced ERK1/2 phosphorylation and changes in the rate of Ca(2+) release from the ER associated with the inhibition of the sarco/endoplasmic reticulum Ca(2+)-ATPase (time to peak [Ca(2+)](CYT) = 188.7 ± 34.6 s (TRPC1 siRNA) versus 124.0 ± 9.5 s (non-targeting siRNA); P<0.05). These studies indicate that EMT in MDA-MB-468 breast cancer cells is associated with a pronounced remodeling of Ca(2+) influx, which may be due to altered ORAI1 and/or TRPC1 channel function. Our findings also suggest that TRPC1 channels in MDA-MB-468 cells contribute to ORAI1-mediated Ca(2+) influx in non-stimulated cells.

SUBMITTER: Davis FM

PROVIDER: S-EPMC3364242 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Non-stimulated, agonist-stimulated and store-operated Ca2+ influx in MDA-MB-468 breast cancer cells and the effect of EGF-induced EMT on calcium entry.

Davis Felicity M FM Peters Amelia A AA Grice Desma M DM Cabot Peter J PJ Parat Marie-Odile MO Roberts-Thomson Sarah J SJ Monteith Gregory R GR

PloS one 20120530 5

In addition to their well-defined roles in replenishing depleted endoplasmic reticulum (ER) Ca(2+) reserves, molecular components of the store-operated Ca(2+) entry pathway regulate breast cancer metastasis. A process implicated in cancer metastasis that describes the conversion to a more invasive phenotype is epithelial-mesenchymal transition (EMT). In this study we show that EGF-induced EMT in MDA-MB-468 breast cancer cells is associated with a reduction in agonist-stimulated and store-operate ...[more]

PMID: 22666335

Similar Datasets

Project description:Mammalian target of rapamycin (mTOR) is a serine/threonine kinase involved in multiple intracellular signaling pathways promoting tumor growth. mTOR is aberrantly activated in a significant portion of breast cancers and is a promising target for treatment. Rapamycin and its analogues are in clinical trials for breast cancer treatment. Patterns of gene expression (metagenes) may also be used to simulate a biologic process of effects of a drug treatment. In this study, we tested the hypothesis that the gene-expression signature regulated by rapamycin could predict disease outcome for patients with breast cancer. Results: Colony formation and sulforhodamine B (IC50 < 1nM) assays, and xenograft animals showed that MDA-MB-468 cells were sensitive to treatment with rapamycin. The comparison of in vitro and in vivo gene expression data identified a signature, termed rapamycin metagene index (RMI), of 31 genes upregulated by rapamycin treatment in vitro as well as in vivo (false discovery rate of 10%). In the Miller dataset, RMI was significantly associated with tumor size or lymph node status. High (>75) percentile) RMI was significantly associated with longer survival (P = 0.015). On multivariate analysis, RMI (P = 0.029), tumor size (P = 0.015) and lymph node status (P = 0.01) were prognostic. In van 't Veer study, RMI was not associated with the time to develop distant metastasis (P = 0.41). In Wang dataset, RMI predicted time to disease relapse (P = 0.09). Conclusions: Rapamycin-regulated gene expression signature predicts clinical outcome in breast cancer. This supports the central role of mTOR signaling in breast cancer biology and provides further impetus to pursue mTOR-targeted therapies for breast cancer treatment. Mol Cancer. 2009 Sep 24;8(1):75. Experiment Overall Design: Rapamycin treatment of MDA-MB-468 breast cancer cell line: Experiment Overall Design: MDA-MB-468 cell line was treated by DMSO (vehicle) and 100 nM rapamycin for 24 hours. We sought to identify differentially expressed genes. Experiment Overall Design: Rapamycin treatment of breast tumor xenografts: Experiment Overall Design: MDA-MB-468 cells were inoculated in the mammary fat pad of female nude mice. When resulting tumor volumes had reached 75-150 mm3, the mice were divided in four groups. Groups 1 and 2 received a single injection of DMSO (vehicle) or rapamycin (15 mg/kg) intraperitoneally and sacrificied 24 h later (1-day groups). Groups 3 and 4 received weekly injections of DMSO or rapamycin for 3 weeks and sacrificied 24 h after the last injection (22-day groups).

Dataset Information

Non-stimulated, agonist-stimulated and store-operated Ca2+ influx in MDA-MB-468 breast cancer cells and the effect of EGF-induced EMT on calcium entry.

Publications

Non-stimulated, agonist-stimulated and store-operated Ca2+ influx in MDA-MB-468 breast cancer cells and the effect of EGF-induced EMT on calcium entry.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets