Getting the Details: Images of Cancer

Published Oct 25, 2011

Studies of specialised proteins by KTH researcher Helena Wållberg may have important implications for the future of cancer diagnostics. Her work is intended to allow doctors to one day distinguish tumours from healthy tissues and develop targeted treatments.

A substantial complication in both detection and treatment of most cancers is that they hijack the body’s own cells to form tumours, which makes the cancer both hard to see in medical images and difficult to attack without damaging other tissues. It’s the fundamental reason such broad treatments as radiation and chemotherapy are commonly accompanied by severe side effects.

Helena Wållberg, who recently received her Ph.D from KTH, works with protein molecules developed by Affibody AB, a spin-off biotechnology company based on research conducted jointly by KTH and Karolinska Institute. “The goal is to develop diagnostic visualisation tools that will make more specific cancer treatments possible with fewer side effects”, she says.

This visualisation begins with an injection of target-seeking molecules known as radiotracers, which can be tracked through their radioactive tags as they concentrate in the tumour tissue. A special camera detects the radioactive decay to identify areas where the cancer may have metastasised. Wållberg’s research to date has focussed on ovarian and breast cancer.

“We’re looking at a protein called HER2 [Human Epidermal Growth Factor Receptor 2], which is often overrepresented in patients with these cancers. We use an Affibody molecule that binds specifically with HER2.”

The same Affibody molecules may also be used to develop pharmaceuticals that will both identify and treat tumours while leaving healthy tissues unaffected. “Any molecules that don’t bind with a target protein are simply eliminated in the patient’s urine”, explains Wållberg.

Wållberg was awarded her doctorate from the KTH School of Biotechnology in October this year after successfully defending her thesis entitled “Design and Evaluation of Radiolabeled Affibody Tracers for Imaging of HER2-expressing Tumors”. But she made a name for herself while still a candidate by co-authoring no fewer than 14 articles published in peer-reviewed scientific journals. Her collaborators included researchers from KTH, Uppsala University, Karolinska Institute and Karolinska Hospital.

“In practical terms, my work is about developing and improving Affibody molecules used in diagnosis and visualisation of cancer tumours”, she says. “Hopefully this will lead to earlier diagnosis and treatment, and to lower health care costs caused by incorrect treatment. We spend a lot of money these days on drugs that turn out to be ineffective or cause unnecessary side effects.”

Kevin Billinghurst; kb2@kth.se

About Affibody molecules

Affibody molecules are small proteins engineered to bind to a large number of target proteins or peptides with high affinity, imitating monoclonal antibodies. Affibody molecules are used in biochemical research and are being developed as potential new biopharmaceutical drugs.

Scientific articles co-authored by Helena Wållberg

Molecular Design and Optimization of 99mTc-labeled Recombinant Affibody Molecules

On the selection of a tracer for PET imaging of HER2-expressing tumors

Evaluation of the radiocobalt-labeled [MMA-DOTA-Cys61]-Z HER2:2395(-Cys) affibody molecule

About Affibody-mediated biotherapy