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.
Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute
Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy