Transition state may offer important window of time for treatment.
Timing may be decisive when it comes to overcoming cancer's ability to evade treatment. By hitting breast cancer cells with a targeted therapeutic immediately after chemotherapy, researchers from Brigham and Women's Hospital (BWH) were able to target cancer cells during a transitional stage when they were most vulnerable, killing cells and shrinking tumors in the lab and in pre-clinical models. The team reports its findings in Nature Communications on February 11.
This confocal microscopy image depicts drug-tolerant cancer cells. By hitting breast cancer cells with a targeted therapeutic immediately after chemotherapy, researchers were able to target cancer cells during a transitional stage when they were most vulnerable.
Credit: Image courtesy of Aaron Goldman
"We were studying the fundamentals of how resistance develops and looking to understand what drives relapse. What we found is a new paradigm for thinking about chemotherapy," said senior author Shiladitya Sengupta, PhD, associate bioengineer at BWH.
Previous studies have examined cancer stem cells (CSCs) - small populations of cells within a tumor that are resistant to chemotherapy. Sengupta and his colleagues took breast cancer cells that did not have the markings of CSCs and exposed them to docetaxel, a common chemotherapy drug.
The team found that after exposure to chemotherapy, the cells began developing physical markings usually seen in CSCs, including receptors on the cell surface to which specific proteins can bind. These "markers of stemness" suggested that the cells were transitioning into a different state, during which time they might be vulnerable to other cancer drugs.
To test this, the researchers treated the cells with a variety of targeted therapeutics immediately after chemotherapy. The researchers observed that two drugs each killed a large fraction of the cells that had begun transitioning: dasatinib, a drug that targets the Src Family Kinase (SFK) and RK20449, a new drug in pre-clinical testing that specifically targets one of the SFK proteins called Hck.
The researchers confirmed these findings in a mammary carcinoma mouse model - treatment with dasatinib just a few days after administering two high doses of chemotherapy prevented tumor growth and increased survival rates.
Treating cells simultaneously with docetaxal and dasatinib or administering dasatinib after a longer period of time did not produce the same effects. The researchers theorize that the cancer cells go through a temporary transition state, which means that administering the drugs in a very specific timeframe and sequence is important.
"By treating with chemotherapy, we're driving cells through a transition state and creating vulnerabilities," said first author Aaron Goldman, PhD, a postdoctoral fellow in biomedical engineering at BWH. "This opens up the door: we can then try out different combinations and regimens to find the most effective way to kill the cells and inhibit tumor growth."
To make these observations, the researchers developed and leveraged three-dimensional "explants" - tissue derived from a patient's tumor biopsy and grown in serum from that specific patient for research purposes. This model mimics the tumor's microenvironment and preserves the tumor's cellular diversity.
In a continuation of this work, Goldman is also using mathematical modeling to pursue the most effective dose of chemotherapy to induce the vulnerable transition state of the cancer cell demonstrated in this research.
"Our goal is to build a regimen that will be efficacious for clinical trials," said Goldman. "Once we understand specific timing, sequence of drug delivery and dosage better, it will be easier to translate these findings clinically."
This work was supported by a DoD BCRP Collaborative Innovator Grant (W81XWH-09-1-0700), NIH RO1 (1R01CA135242), DoD Breakthrough Award (BC132168), an American Lung Association Innovation Award (LCD-259932-N), Indo-US Joint Center Grant from IUSSTF, American Cancer Society Postdoctoral Fellowship and NSERC, Canada.
Haley Bridger | EurekAlert!
Complete skin regeneration system of fish unraveled
24.04.2018 | Tokyo Institute of Technology
Scientists generate an atlas of the human genome using stem cells
24.04.2018 | The Hebrew University of Jerusalem
At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.
Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...
Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.
Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
24.04.2018 | Life Sciences
24.04.2018 | Materials Sciences
24.04.2018 | Trade Fair News