Michel Aubé and colleagues from Université Laval and Institut national de santé publique in Québec, Canada have published findings suggesting that DDT’s main metabolite, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p’-DDE), could increase breast cancer progression. They suggest a mechanism whereby p,p’-DDE opposes the androgen signalling pathway that inhibits growth in hormone-responsive breast cancer cells.
The team tested the effect of p,p’-DDE on the proliferation of CAMA-1 cells, a human breast cancer cell line that expresses the estrogen receptor alpha (ERa) and the androgen receptor (AR), either with or without physiological concentrations of estrogens and androgens. They also assessed p,p’-DDE-induced modifications in cell cycle entry and the expression of sex-steroid dependent genes including ESR1 and CCND1, the latter coding for a key protein involved in cell proliferation.
When estrogens and androgens were present in the cell culture medium, increasing concentrations of p,p’-DDE accelerated the growth of CAMA-1 breast cancer cells. p,p’-DDE had a similar effect on the proliferation of MCF7-AR1 cells, an estrogen responsive cell line genetically engineered to over express the AR. Adding the potent androgen dihydrotestosterone together with estradiol to the cell culture medium decreased the recruitment of CAMA-1 cells in the S phase and the expression of ESR1 and CCND1, by comparison with cells treated with estradiol alone. These androgen-mediated effects were blocked with similar efficacy by p,p’-DDE and the potent antiandrogen hydroxyflutamide.
“Our results suggest that in addition to estrogenic compounds, which have been the main focus of researchers over the past decades, chemicals that block the AR could favour breast cancer progression” says Pierre Ayotte, who is leading the research team.
Ayotte’s team had previously linked concentrations of p,p’-DDE with tumour aggressiveness in women with breast cancer. They are now investigating the effect on breast cancer cell proliferation of a complex mixture of environmental chemicals, similar to that found in the blood of women, which comprises compounds with estrogenic and antiandrogenic activities.
Researchers discover natural product that could lead to new class of commercial herbicide
16.07.2018 | UCLA Samueli School of Engineering
Advance warning system via cell phone app: Avoiding extreme weather damage in agriculture
12.07.2018 | Leibniz-Zentrum für Agrarlandschaftsforschung (ZALF) e.V.
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
17.07.2018 | Information Technology
17.07.2018 | Materials Sciences
17.07.2018 | Power and Electrical Engineering