'Flying saucer' quantum dots hold secret to brighter, better lasers

March 23, 2017

Fresh insights into living cells, brighter video projectors and more accurate medical tests are just three of the innovations that could result from a new way of fabricating lasers.The new method, developed by an international research team from U of T Engineering, Vanderbilt University, the Los Alamos National Laboratory and others, produces continuous laser light that is brighter, less expensive and more tuneable than current devices by using nanoparticles known as quantum dots.The project included a number of national and international partners. Computer simulations in collaboration with the University of Ottawa and the National Research Council guided the design of the quantum dots. Analytical tests from Vanderbilt's Institute of Nanoscale Science and Engineering in Nashville, TN, as well as the University of New Mexico's Center for High Technology Materials in Albuquerque, NM and Los Alamos confirmed that the final products had the desired shape, composition and behaviour by analyzing individual quantum dots at the atomic level."We were impressed not only by the engineered structure itself but also by the level of uniformity they have achieved," says Sandra Rosenthal, director of the Vanderbilt Institute for Nanoscale Science and Engineering. "[The] team has managed to create quantum dots with a unique and elegant structure. This is exciting research."


Study catches ‘notorious’ drug pump in action

March 16, 2017

Researchers at Vanderbilt University Medical Center (VUMC) have mapped the conformational changes that occur in a protein “notorious” for pumping chemotherapeutic drugs out of cancer cells and blocking medications from reaching the central nervous system.​ Their report, published this week as a letter in the journal Nature, is an important step forward in understanding — and perhaps one day interfering with — the highly dynamic ABC transporter known as P-glycoprotein, said corresponding author Hassane Mchaourab, Ph.D.

Esophageal cancer complexities

March 16, 2017

Esophageal adenocarcinoma (EAC) is an aggressive cancer that is increasing in incidence in the United States. Wael El-Rifai, M.D., Ph.D., and colleagues studied the molecular interaction between gene expression, genomics and epigenetics in EAC. In a study published in Scientific Reports, the researchers utilized an integrated approach to analyze changes in gene expression, DNA copy numbers and promoter DNA methylation (an epigenetic modification) in human EAC tissue samples.

For female mosquitoes, two sets of odor sensors are better than one

March 16, 2017

Biologists who study the malaria mosquito’s “nose” have found that it contains a secondary set of odor sensors that seem to be specially tuned to detect humans. The discovery could aid efforts to figure out how the insects target humans and develop a preference for them. “This appears to be a more primitive olfactory system and one which Anopheles uses to detect humans,” said Cornelius Vanderbilt Professor of Biological Sciences Laurence Zwiebel, who directed the study. “It fills important gaps in the mosquito’s chemosensory perception that are not provided by the OR system.” Read more

Fesik Lab Expands Collaboration with Boehringer Ingelheim for Difficult-to-Treat Cancers

March 6, 2017

A multi-year program with pharmaceutical company Boehringer Ingelheim complements an already existing collaboration with Vanderbilt University by focusing on the research and development of small molecule compounds targeting the protein SOS (Son of Sevenless). This molecule activates KRAS, a molecular switch that plays a central role in the onset of some of the deadliest cancers. The story mentions the laboratory of Stephen W. Fesik, Orrin H. Ingram II Professor of Cancer Research, and quotes Lawrence J. Marnett, Mary Geddes Stahlman Professor of Cancer Research and dean of basic sciences for the Vanderbilt University School of Medicine.

Team identifies ‘switch’ involved in DNA replication  

March 3, 2017

DNA replication is an extraordinarily complex multi-step process that makes copies of the body’s genetic blueprint. It is necessary for growth and essential to life. Now researchers at the California Institute of Technology (Caltech) and Vanderbilt University have found evidence that one of those steps may involve the telephone-like transmission of electrical signals regulated by a chemical “switch.”

“We propose this as a fundamentally new transformative idea about how you could get communication between proteins over very long spatial distances using DNA as a wire,” said Walter Chazin, Ph.D., the Chancellor’s Professor of Medicine, professor of Biochemistry and Chemistry and director of the Vanderbilt Center for Structural Biology.

Investigators seek new way to define cell identity

March 3, 2017

Jonathan Irish, Ph.D., and his colleagues have developed a new language, one that can be used to describe and identify cells.

The language — marker enrichment modeling, or MEM — assigns a “MEM label” to cells based on certain features of the cell, usually proteins. Irish and his colleagues hope that MEM, which they recently reported in the journal Nature Methods, will be widely adopted and used to generate a “Who’s Who” database of cell types.

Ohi Selected as 2017 Chancellor Faculty Fellow

February 6, 2017

Twelve outstanding faculty members from across the university have been named to the 2017 class of Chancellor Faculty Fellows. The class comprises highly accomplished, recently tenured faculty from the social sciences, life and physical sciences, clinical sciences and humanities, as well as law, mathematics and engineering.

Melanie Ohi is an associate professor of cell and developmental biology and associate professor of biochemistry.


New target for chronic infection

February 6, 2017

The greatest risk factor for gastric cancer is chronic infection by the bacterium, Helicobacter pylori.

In a study in mice published by the Proceedings of the National Academy of Sciences, Dana Hardbower, Keith Wilson, M.D., and colleagues found that macrophage activation has a critical role in regulating H. pylori colonization and gastric inflammation.



Bacterial signaling systems

February 6, 2017

Bacteria respond to their environments – to ensure their own survival and proliferation – using two-component systems (TCSs). These systems consist of a bacterial receptor and a response regulator that changes bacterial behavior by modifying gene expression. Most bacterial receptors and response regulators are exclusive pairs that do not interact with components of other TCSs.

In the Jan. 10 issue of Science Signaling, Maria Hadjifrangiskou, Ph.D., and colleagues demonstrate that two different TCSs interact in a strain of uropathogenic E. coli – bacteria that cause urinary tract infections.


Gene mutation discovery may hold autism clues: study

February 3, 2017

Researchers at Vanderbilt have identified what may be a genetic “smoking gun” for autism spectrum disorder (ASD) — a mutation in the gene for the critical neuronal protein CaMKII.

While no single mutation can explain the immensely complicated picture presented by ASD, this study is the first to link a naturally occurring mutation in the CAMK2-alpha gene with a specific neuropsychiatric disorder, said Roger Colbran, Ph.D., professor and interim chair of the Department of Molecular Physiology and Biophysics.

Further characterization of the biochemical consequences of this mutation likely will provide novel insights into the molecular mechanisms underlying ASD and may suggest new approaches to improve early diagnosis and/or treatment of the disorder, said Colbran, a Vanderbilt Kennedy Center investigator.

The group’s findings were posted online last week by the Journal of Neuroscience.


Hasty named to new VUSM Basic Sciences role

February 3, 2017

Alyssa Hasty, Ph.D., professor of Molecular Physiology and Biophysics, has been named Associate Dean for Faculty Development for Basic Sciences at Vanderbilt University School of Medicine.

Hasty has devoted much of her career to mentoring and encouraging students and junior faculty members. She was one of the founding members and chair of the steering committee of the Women on Track program that began in 2005 and is ongoing. The goal of the program is to support women who are on the tenure track and ensure they have the tools they need to succeed.