New imaging technique identifies receptors for targeted cancer therapy

November 14, 2014

Dartmouth researchers have developed a fluorescence imaging technique that can more accurately identify receptors for targeted cancer therapies without a tissue biopsy. They report on their findings in "Quantitative in vivo immunohistochemistry of epidermal growth factor receptor using a receptor concentration imaging approach," which was recently published in Cancer Research.

"Protein overexpression is a hallmark of certain cancers and is used in clinical oncology to personalize treatment through tumor detection, molecular therapies, and therapeutic monitoring," said lead author Kimberley S. Samkoe, assistant professor of Surgery at the Geisel School of Medicine and adjunct assistant professor at Thayer School of Engineering. "Protein expression is currently measured through a total protein analysis of tumor tissue. This new technique allows us to accurately determine the amount of protein receptors available for binding a drug without invasive biopsy."

The researchers developed a dual-tracer in vivo receptor concentration imaging (RCI) technique that involves the simultaneous injection of both a targeted and a non-targeted imaging agent. They then studied the protein expression of five tumors, comparing the RCI data to that determined by clinical immunohistochemistry, either scored by a pathologist (as performed in the clinic) or analyzed independently by a computer. They found that the protein expression determined by RCI strongly correlated to that determined by tissue analysis. They also found that commonly used techniques of measuring protein expression, such as Western blots or flow cytometry, did not correlate to the RCI values, and in fact over-predicted the number of receptors available for therapeutic or diagnostic targeting.

"Accurately determining the population of protein receptors in a tumor available for targeting by molecular therapies or diagnostic imaging agents can greatly impact oncology patient outcomes," said Samkoe. "Our in vivo receptor concentration imaging technique is a novel approach for fluorescence imaging that can potentially impact clinical assessment of tumor status and malignant tissue classification."

Samkoe noted that this study looks at the average receptor expression within the tumor. The next step will be to look at tumors on a microscopic level in order to correlate receptor expression to distinct physiological features such as cellular viability, cellular type, vascularity, and overall tumor architecture
The study was collaboration between Geisel School of Medicine at Dartmouth College, the Thayer School of Engineering, members of the Norris Cotton Cancer Center, and the Wellman Center for Photomedicine at Massachusetts General Hospital and was supported by NIH grants R01CA156177, U54CA151662 and P01CA84203.

About Norris Cotton Cancer Center at Dartmouth-Hitchcock:

Norris Cotton Cancer Center combines advanced cancer research at Dartmouth and the Geisel School of Medicine with patient-centered cancer care provided at Dartmouth-Hitchcock Medical Center, at Dartmouth-Hitchcock regional locations in Manchester, Nashua, and Keene, NH, and St. Johnsbury, VT, and at 12 partner hospitals throughout New Hampshire and Vermont. It is one of 41 centers nationwide to earn the National Cancer Institute's "Comprehensive Cancer Center" designation. Learn more about Norris Cotton Cancer Center research, programs, and clinical trials online at

The Geisel School of Medicine at Dartmouth

Related Protein Articles from Brightsurf:

The protein dress of a neuron
New method marks proteins and reveals the receptors in which neurons are dressed

Memory protein
When UC Santa Barbara materials scientist Omar Saleh and graduate student Ian Morgan sought to understand the mechanical behaviors of disordered proteins in the lab, they expected that after being stretched, one particular model protein would snap back instantaneously, like a rubber band.

Diets high in protein, particularly plant protein, linked to lower risk of death
Diets high in protein, particularly plant protein, are associated with a lower risk of death from any cause, finds an analysis of the latest evidence published by The BMJ today.

A new understanding of protein movement
A team of UD engineers has uncovered the role of surface diffusion in protein transport, which could aid biopharmaceutical processing.

A new biotinylation enzyme for analyzing protein-protein interactions
Proteins play roles by interacting with various other proteins. Therefore, interaction analysis is an indispensable technique for studying the function of proteins.

Substituting the next-best protein
Children born with Duchenne muscular dystrophy have a mutation in the X-chromosome gene that would normally code for dystrophin, a protein that provides structural integrity to skeletal muscles.

A direct protein-to-protein binding couples cell survival to cell proliferation
The regulators of apoptosis watch over cell replication and the decision to enter the cell cycle.

A protein that controls inflammation
A study by the research team of Prof. Geert van Loo (VIB-UGent Center for Inflammation Research) has unraveled a critical molecular mechanism behind autoimmune and inflammatory diseases such as rheumatoid arthritis, Crohn's disease, and psoriasis.

Resurrecting ancient protein partners reveals origin of protein regulation
After reconstructing the ancient forms of two cellular proteins, scientists discovered the earliest known instance of a complex form of protein regulation.

Sensing protein wellbeing
The folding state of the proteins in live cells often reflect the cell's general health.

Read More: Protein News and Protein Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to