Although "xenografting" with either cells or fresh tissue is already used widely to test cancer therapies, the Hopkins design is personalized to each patient who has relapsed after an initial course of chemotherapy. "Eventually our approach offers a promising way to individualize therapy earlier in treatment instead of first giving everyone the standard drug gemcitabine, which has a success rate of less than 10 percent," says Antonio Jimeno, M.D., instructor in oncology at the Johns Hopkins Kimmel Cancer Center.
Results of preliminary tests of the Hopkins method in 14 patient samples taken after surgery shows that each xenografts' genetic profile remained stable through three and four generations of mice so that "test drives" would accurately represent a patient's tumor. The scientists also found they could build xenografts in 80 percent of their pancreatic patients, a success rate higher than efforts with colon cancer patients, for which rates are typically less at about 50 percent.
Reporting on their work in a recent issue of Clinical Cancer Research and at the September meeting of the American Association for Cancer Research in Chicago, the Hopkins team said it took tiny bits of a patient's tumor removed after surgery, and implanted them into one or two mice. After letting the resulting tumor grow for several months, they removed the mass and cut it into pieces to implant into additional mice, eventually creating 20 animals containing matching samples of a single patient's tumor.
"By scaling up this way, we got enough tumor samples to randomize mice into groups for testing candidate drugs," says Manuel Hidalgo, M.D., Ph.D., associate professor at Hopkins' Kimmel Cancer Center, who says the process currently requires about six months to get information on which drugs work best. "In the meantime, most patients are receiving their first rounds of chemotherapy and radiation. Initially, xenograft information can guide therapy once patients relapse, which is generally in nine to twelve months with pancreatic cancer."
The Hopkins group is conducting a clinical trial of the xenograft model in 40 patients undergoing surgery at Johns Hopkins for non-metastatic pancreas cancer. In the trial, a portion of each patient's tumor is shuttled directly from the pathologist to the Hopkins' laboratory where the first mice are implanted and the 20 mice "built" to test the 20 or so drugs currently available against pancreatic cancer.
Says Jimeno, "If this model works, then we'll need to develop ways to apply it to a broader population of pancreatic cancer patients since there are significant laboratory resources necessary for each patient."
Information from the study also may reveal new biomarkers that predict drug response and data on how certain therapies act within the body. Ultimately, they hope to broaden use of xenografting to tumor samples that can be accessed via biopsy through fine needle aspiration.
Pancreatic cancer accounts for more than 33,000 new cases in the United States and almost as many deaths. It is one of the deadliest cancers, with less than five percent of patients living beyond five years.
Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care
Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | Max-Planck-Institut für chemische Ökologie
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
17.11.2017 | Physics and Astronomy
17.11.2017 | Health and Medicine
17.11.2017 | Studies and Analyses