Scientists in the Netherlands have developed a way to watch cancers spreading into other organs in real time.
The process of metastasis - spread to remote sites around the body - is usually the cause of the majority of cancer deaths, yet we barely understand how this actually happens. Now Laila Ritsma and her colleagues in the Netherlands at the Hubrecht Institute have developed a technique to enable them to watch cancers invading other organs. This same procedure is also enabling them to test drugs and other strategies designed block metastasis.
The adenocarcinoma (lower two-thirds of the image) is moderately differentiated; morphologically, it consists of poorly formed glands and is surrounded by a desmoplastic stroma.
The liver parenchyma (upper one-third of the image) has cholestasis (yellow pigment = bile) due to mass effect from the tumour. (c) Nephron @ wikipedia" alt="Low magnification micrograph of a metastatic adenocarcinoma to the liver. Liver biopsy. H&E stain." />Writing in Science Translational Medicine, the Dutch team describe an approach they called the abdominal imaging window, which enables them to watch, over periods of days to weeks, as tumours take root in the liver and other organs of experimental mice.
The system involves implanting into the abdominal wall a small metal ring resembling a port-hole. This "window" contains a small glass coverslip sealed into the metal ring, enabling the scientists to peer in while ensuring that the abdominal cavity remains sterile. Mice that were given the implants showed no signs of discomfort, distress or infection for up to 63 days, the longest period studied.
The team were able to use this system and an adapated microscope to peer inside and trace over time the fate of cancer cells labelled with a glowing protein and injected into the animals' spleens.
The researchers were able to watch as the malignant cells migrated to the liver where they left the blood stream and inveigled their way some distance into the local tissue before beginning to divide and initiate a tumour deposit.
In a separate group of animals, the team adminstered an experimental agent intended to block cancer cells migrating; sure enough, the new system showed that, following treatment with the drug, invasion was reduced 1.7 fold. Other organs, including the kidneys, were also successfully imaged in the same way.
This shows that this technique could equip cancer biologists with a powerful new weapon to aid their quest to understand tumour behaviour and to test novel cancer therapies.