But now, in work about to be published in the "Journal of Cellular Biochemistry", a team of Portuguese scientists shows that progesterone seems to sustain the formation of blood vessels, which, by supplying nutrients to the tumour cells, are vital for breast cancer progression. This finding has important implications not only for a better understanding of the disease, but also for present and future therapeutic approaches against it.
Breast cancer is the second most common cancer in the world with approximately 1 million of new cases every year, even if the disease tends to have a relatively favourable prognosis. One of the reasons for this is the fact that a majority of breast cancers are hormone-dependent, and treatments blocking these hormones (and consequently cancer progression) can be extremely effective, sometimes even more than chemotherapy.
In fact, ovarian hormones known to play an important role in the development of normal breast tissue - such as oestrogen and progesterone - also seem to be involved in breast cancer development, with 70 to 80% of primary breast tumours showing oestrogen and/or progesterone receptors in their cells. These receptors act as on-off switch; when the right molecule (in this case oestrogen or progesterone) binds to its specific receptor, the switch is turned on, leading, in the case of breast cancer, to disease progression. In result, anti-hormonal therapy (especially anti-oestrogen therapy), which blocks the hormones’ action, is widely used against the disease with good results.
But if oestrogen has been clearly associated with cancer growth, the role of progesterone in breast cancer (and consequently the importance and the specific mechanism of progesterone-blocking therapy) is much less clear.
But now Raquel Soares, Susana Guerreiro and Mónica Botelho from the University of Porto in Portugal found that breast cancer cells that respond to progesterone, produce, when exposed to the hormone, Platelet-derived growth factor A (PDGF-A) a protein known to stimulate cell growth and division. Furhermore, PDGF-A did not seem to act directly on the tumour cells, but was instead released into the space outside of the cell suggesting an effect on neighbouring cells.
Interaction between tumour cells and their environment is crucial for cancer progression and in fact PDGF-A has been suggested to be involved in the formation of new blood vessels (also called angiogenesis). Angiogenesis is a process crucial for cancer sustainability since without new blood vessels around the tumour site to supply nutrients, cancerous cells will starve and die. To test if PDGF-A could be in fact involved in the formation of blood vessels around breast cancer tumour sites, Soares and colleagues decided to analyse smooth muscle cells, which are known to be involved in this process while also have been described as having receptors for PDGF-A. And in fact, PDGF-A (and so progesterone) was found to increase the growth and viability of smooth muscle cells confirming a role to both these molecules supporting angiogenesis.
What Soares and colleagues’ work strongly suggest is that progesterone stimulates cancer development by helping the formation and stability of blood vessels formed adjacent to the tumour cells. These new blood vessels are, not only crucial to the supply of nutrients to cancer cells, but also important “exits” for these cells to spread throughout the body. These results show how current anti-progesterone therapies block cancer progression by targeting not only progesterone-dependent cancer cells but also the formation of new blood vessels, and emphasise the importance of continue to pursue anti-progesterone therapeutics.Piece researched and written by:
Catarina Amorim | alfa
Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH
Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
20.01.2017 | Awards Funding
20.01.2017 | Materials Sciences
20.01.2017 | Life Sciences