Basal-like breast cancers (BLC) are highly aggressive tumors with a relatively poor prognosis that account for approximately 15% of sporadic human breast cancer. Sporadic BLC share certain characteristics with most of the breast cancers from patients carrying a germline mutation in the BRCA1 breast cancer suppressor gene. Among their similarities, sporadic BLC and BRCA1 cancers do not express the estrogen receptor and do not overproduce HER2 protein. Thus, therapeutics targeting estrogen receptor or targeting HER2 currently used in treating some other types of breast cancers are unlikely to be useful for treating these breast cancers. However, sporadic BLC contain normal BRCA1 genes. A new study published in the February issue of Cancer Cell provides evidence that X chromosome abnormalities contribute to the pathogenesis of both the sporadic BRCA1 normal BLC and the inherited BRCA1 mutant breast cancer.
Defects in the BRCA1 gene have been linked to an abnormality in a mechanism that contributes to the stability of sex chromosomes in women. In mammals, male cells contain an X and a Y chromosome, while female cells contain two X chromosomes. Normally, a process called X inactivation occurs in early female embryos; it leads to silencing of one of the two X chromosomes in derivative embryonic and adult somatic cells. The authors had previously shown that loss of the inactive X chromosome (Xi) occurs in BRCA1 mutation-carrying breast cancers. Given the similarities between BRCA1-associated cancer and sporadic BLC, Drs. Andrea Richardson, Zhigang Wang, Dirk Iglehart, David M. Livingston, and Shridar Ganesan, and colleagues from the Dana-Farber Cancer Institute and Brigham and Womens Hospital, examined whether sporadic BLC display abnormalities in the management of the Xi chromosome.
The researchers found that, like BRCA1-associated cancers, most sporadic BLC have consistently lost the Xi and displayed a higher than normal number of apparently active X chromosomes These tumors also showed increased expression of a small, but specific, subset of X chromosomal genes. Interestingly, since all sporadic BLC analyzed displayed normal BRCA1 genes and gene expression, it was hypothesized that BLC have acquired defects in genes other than BRCA1 that contribute to some of the same cellular pathways as those that are defective in BRCA1-associated cancers. One wonders whether one or more of these pathways support(s) the maintenance of a normal Xi. "These results provide new insight into possible pathogenic mechanisms underlying both sporadic and BRCA1-associated basal-like breast cancer," explain the authors. Ideally, a better understanding of how two active X chromosomes are associated with cancer development and progression could lead to new insights into rational treatment strategies for these subtypes of breast cancer.
Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz
Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences