Mitochondrial blindness -- Newman's Emory story

Neuro-ophthalmologist Nancy Newman’s 2017 Dean’s Distinguished Faculty Lecture and Award were unexpectedly timely. Her talk on Tuesday was a tour of her career and mitochondrial disorders affecting vision, culminating in a description of gene therapy clinical trials for the treatment of Leber’s hereditary optic neuropathy. The sponsor of those studies, Gensight Biologics, recently presented preliminary data on a previous study of their gene therapy at the American Academy of Neurology meeting in April. Two larger trials Read more

IMSD program nurtures young scientists

The IMSD (Initiative to Maximize Student Development) program nurtures and mentors a diverse group of young scientists at Read more

Flu meeting at Emory next week

We are looking forward to the “Immunology and Evolution of Influenza” symposium next week (Thursday the 25th and Friday the Read more

Cancer

HER2-positive breast cancer treatment options studied

Emory oncologist Ruth O’Regan, MD, is leading a trial testing whether Afinitor can reverse resistance to Herceptin in metastatic HER2-positive breast cancer patients. As part of the trial, some patients been receiving a drug called Afinitor (everolimus) along with chemotherapy and Herceptin (trastuzumab).

Ruth O'Regan, MD

About 25 percent to 30 percent of breast cancers are HER2 -positive, which means they test positive for a protein called human epidermal growth factor receptor-2 (HER2). This protein promotes the growth of cancer cells, making HER2 -positive breast cancers more aggressive than other types.

They also tend to be less responsive to hormone treatment. That’s the bad news. The good news is that this type of cancer responds extremely well to Herceptin.

Herceptin specifically targets HER2 cells, killing them while sparing healthy cells, so side effects are minimal. Its effectiveness has made Herceptin the gold standard of treatment for HER2 -positive breast cancer.

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Posted on by Jennifer Johnson in Cancer Leave a comment

Hold out your finger: Epidemiologist developing test for colon cancer risk

Years from now physicians may be able to determine whether you’re at increased risk for colorectal cancer by drawing blood from the tip of your finger.

Emory University researchers are working to identify biomarkers to detect a person’s chances of developing colon cancer. Much like blood pressure and cholesterol tests can indicate heart disease risk, researchers here hope that some day the makeup of blood and urine will be able to tell who’s at risk for colorectal cancer, why they may be at risk and what they can do to reduce their risk.

Postdoctoral fellows Joy Owen and Veronika Fedirko examine samples in Robin Bostick’s lab at the Winship Cancer Institute of Emory University.

For now, the Emory study team is analyzing the rectal tissue samples of people with colon adenomatous polyps, non-cancerous growths considered precursors to colon cancer, and comparing them to rectal tissue samples from people who don’t have polyps. They’re also looking at whether the differences they detect in rectal tissue can also be found in blood or urine. Currently, no accepted tests exist to determine whether someone may be at risk for colon cancer.

“Most people would rather provide a blood or urine sample than get a rectal biopsy,” says Robin Bostick, MD, MPH, Rollins School of Public Health epidemiology professor and study principal investigator. Bostick is also a clinical faculty member at the Winship Cancer Institute at Emory and a Georgia Cancer Coalition Distinguished Cancer Scholar.

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Looking at simple foods to protect against breast cancer

Researchers at the Winship Cancer Institute of Emory University have found that the hormone adiponectin may reduce the ability of cancer cells to migrate from the breast and invade other tissues. Adiponectin appears to protect against the effects of obesity on metabolism, the heart and blood vessels, the researchers say.

Fat cells make up most of the breast tissue, and some of the hormones produced by fat cells can have tumor-stimulating effects. Previous studies have shown that women with high body mass index (highest fifth) have double the death rate from breast cancer compared to those in the lowest fifth.

Dipali Sharma, PhD

The key to translating this research for patient care lies in finding a way to increase a person’s adiponectin, says Dipali Sharma, PhD, assistant professor of hematology and medical oncology at Winship.

Currently, Winship scientists are testing a molecule found in certain foods that appears to mimic the effects of adiponectin. The molecule is found in grapes, cabbage and green tea.

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Posted on by Vince Dollard in Cancer Leave a comment

Nanotechnology may help surgeons detect cancer

What a cancer patient wants to know after surgery can be expressed succinctly: “Did you get everything?” Having a confident answer to that question can be difficult, because when they originate or metastasize, tumors are microscopic.

Considerable advances have been made in “targeted therapy” for cancer, but the wealth of information available on the molecular characteristics of cancer cells hasn’t given doctors good tools for detecting cancer during surgery – yet.

Even the much-heralded advent of robotic surgery has not led to clear benefits for prostate cancer patients in the area of long-term cancer control, a recent New York Times article reports.

At Emory and Georgia Tech’s joint department for biomedical engineering, Shuming Nie and his colleagues are developing tools that could help surgeons define tumor margins in human patients.

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Posted on by Quinn Eastman in Cancer Leave a comment

Lung cancer clinical trial shows treatment promise

Advanced non-small cell lung cancer (NSCLC) is a challenging disease to treat. More than 200,000 new cases of lung cancer are diagnosed each year, and 85 percent to 90 percent of diagnosed lung cancers fall into the non-small cell type.

A new strategy for treating NSCLC that increases the effectiveness of standard chemotherapy in patients with advanced stage disease has been found by Emory researchers. Recent advances in treatment result in improvement in patient survival noted for all stages of NSCLC.

Saresh Ramalingam, MD

Saresh Ramalingam, MD

Lead investigator Suresh Ramalingam, MD, associate professor of hematology and medical oncology at Winship Cancer Institute of Emory University, along with a consortium of academic institutions that is supported by the National Cancer Institute, published the positive results in The Journal of Clinical Oncology.

In the clinical trial, Emory scientists added a cancer-fighting compound that is used to treat a specific type of lymphoma to standard lung cancer chemotherapy, resulting in an increase in positive response rates in NSCLC patients.

The addition of vorinostat, a compound that affects the function and activity of DNA and various other proteins, to standard chemotherapy treatment of carboplatin and paclitaxel, increased positive response rates in patients from 12.5 percent to 34 percent in a clinical trial of 94 patients with metastatic non-small cell lung cancer.

Vorinostat may be affecting histones, which are spool-like proteins around which the cell’s DNA is wound. These proteins are important for cell division. We believe these molecular effects could enhance the efficacy of carboplatin and paclitaxel, respectively.

Vorinostat is part of an emerging class of anti-tumor agents that interfere with enzymes known as histone deacetylases (HDAC). Inhibiting these enzymes increases the level of acetylation, a modification of proteins in the cell. Vorinostat is sold by Merck as Zolinza and was approved by the FDA in 2006 to treat cutaneous T cell lymphoma.

Ramalingam says this exciting data will have to be further evaluated in confirmatory phase III studies before they can be adopted in routine use. However, HDAC inhibitors can now be considered among the leading targeted agents under evaluation for the treatment of non-small cell lung cancer.

Posted on by Vince Dollard in Cancer Leave a comment

Questions only a network of pathologists can answer

When a patient is fighting a brain tumor, pathologists usually obtain a tiny bit of the tumor, either through a biopsy or after surgery, and prepare a microscope slide. Looking at the slide, they can sometimes (but not always) tell what type of tumor it is. That allows them to have an answer, however tentative, for that critical question from the patient: “How long have do I have?” as well as give guidance on what kind of treatment will be best.

Dan Brat, a pathologist specializing in brain tumors at Emory Winship Cancer Institute, gave a presentation this week explaining how he has been asking more complicated questions, ones only a network of pathologists armed with sophisticated computers can answer:

  • What genes tend to be turned on or off in the various types of brain tumors?
  • What does the pattern look like when a tumor is running out of oxygen?
  • What if we get a “robot pathologist” to look at hundreds of thousands of brain tumor slides?
Under the microscope, the shapes of cell nuclei in brain tumors look different depending on the type of tumor.

Under the microscope, the shapes of cell nuclei in brain tumors look different depending on the type of tumor.

Brat was speaking at a caBIG (cancer Biomedical Informatics Grid) conference, taking place at the Emory Conference Center this week. caBIG is a computer network sponsored by the National Cancer Institute that allows doctors to share experimental data on cancers. Brat explained that low-grade brain tumors come in two varieties: oligodendrogliomas and astrocytomas. Under the microscope, cell nuclei in the first tend to look round and smooth, but the second look elongated and rough. Kind of like the differences between an orange and a potato, he said.  He and colleague Jun Kong designed a computer program that could tell one from the other. They had the program look through almost 400,000 slides, using resources compiled through caBIG (Rembrandt and Cancer Genome Atlas databases). Sifting through the data, they could find that certain genes are turned on in each kind of tumor.

Imagine a "robot pathologist" that can sift through thousands of images from brain tumor samples.

Imagine a "robot pathologist" that can sift through thousands of images from brain tumor samples.

Daniel Brat, MD, PhD, principal investigator for the In Silico Brain Tumor Research Center

Daniel Brat, MD, PhD, principal investigator for the In Silico Brain Tumor Research Center

Eventually, this kind of information could help a patient with a brain tumor get good responses to those “How long?” and “How am I going to get through this?” questions.

Joel Saltz, who leads Emory’s Center for Comprehensive Informatics, has been a central figure in developing tools for centers such as Emory’s In Silico Brain Tumor Research Center. In September 2009, Emory was selected to host one of five “In Silico Research Centers of Excellence” by the National Cancer Institute.

Posted on by Quinn Eastman in Cancer Leave a comment

Strategies to target cancer stem cells

A story in last Friday’s New York Times highlights research on “cancer stem cells”: a fraction of cells in a tumor that are especially resistant to chemotherapy and resemble the body’s non-cancerous stem cells in their ability to renew themselves.

The story describes work by a team at the Broad Institute, who reported in the journal Cell that they had identified compounds that specifically kill cancer stem cells. The hope is that compounds such as these could be combined with conventional treatments to more effectively eliminate cancers.

However, scientists disagree on whether the phenomenon of cancer stem cells extends to different kinds of cancer and what is the best way to target them. Previously not much was known about how to attack these cells.

Work at Emory’s Winship Cancer Institute has been tracking how some biomarkers in cancer cells resemble or differ from those found in stem cells. These markers may help researchers home in on the cancer stem cells.

 

Anticancer therapy must target more than one type of cell. TIC means tumor initiating cell, DTC means differentiated tumor cell, and CPG means cancer progenitor

If "cancer stem cells" play the critical roles some scientists think they do, anticancer therapy must target more than one type of cell. In this figure from Van Meir + Hadjipanayis' review, TIC means tumor initiating cell, DTC means differentiated tumor cell, and CPG means cancer progenitor cells.Â

 

 

In a recent review, Emory brain cancer specialists Erwin Van Meir and Costas Hadjipanayis write:

The “cancer stem cell” hypothesis has invigorated the neuro-oncology field with a breath of fresh thinking that may end up shaking the foundation of old dogmas, such as the widely held belief that glioblastoma tumors are incurable because of infiltrative disease. If the infiltrated cells are in fact differentiated tumor cells, their dissemination beyond the surgical boundary may not be the primary cause of tumor recurrence.

Van Meir, the editor of a new book on brain cancer, adds this comment:

Clearly a lot more work needs to be done to understand the precise cause of glioblastoma recurrence after surgery and chemotherapy and how to prevent it.  The possibility of developing therapeutics that can specifically target the brain cancer stem cells is an exciting new development but will have to proceed with caution to spare normal stem cells in the brain. Developing new imaging tools that can track cancer stem cells in the brain of treated patients is also an important objective and some of the Emory investigators are evaluating the use of nanoparticles to this purpose.

A new faculty member at Winship, Tracy-Ann Read, recently published her research on a molecule that could be used to identify “tumor-propagating cells” in medulloblastoma, a form of brain cancer. She says:

Although cancer stem cells have been identified in many different types of cancer, it is becoming increasingly clear that the properties of these cells may vary greatly among the different tumor types. It is unlikely that one  therapeutic agent will be able to target the cancer stem cells in for example all types brain tumors. Hence  much work still needs to be done in terms of analyzing the properties of these cells in each tumor type and identifying the genes that are responsible for their unique ability to propagate the tumors. 

Winship’s director Brian Leyland-Jones has also reported at the San Antonio Breast Cancer Symposium that molecules that distinguish a hard-to-treat form of breast cancer resemble those that maintain stem cells.

Nice round-up from Nature’s stem cell blog editor Monya Baker

Posted on by Quinn Eastman in Cancer Leave a comment
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