SCIENTISTS SHINE LIGHT ON NEW WAY TO FIGHT CANCER

Scientists funded by the Association for International Cancer Research have developed tiny fluorescent crystals barely visible to the human eye that could revolutionise cancer diagnosis and treatment in a big way.

In one of the largest international and interdisciplinary collaborations the UK-based charity has funded, researchers from France, Russia and Britain specialising in the highly-complex field of nanotechnology have developed a method of labeling specific molecules within cells using nano-scale marker particles that can be detected by their very strong fluorescence when any light from ultraviolet to red is shone on them.

Already the team are using them to study tissue samples from patients to detect and monitor in real time specific molecules inside cancer cells, made possible because of a series of scientific triumphs not previously achieved.

The first was to work out how to synthesise the nanocrystals in large enough quantities to use them to study biological samples. Next they had to make them soluble in water and the third stage was to develop a coating for the nanocrystals that prevented them from being too toxic to biological material.

Once these hurdles had been overcome, Dr Igor Bronstein of the University of York (currently working at the Institute for Animal Health in Compton, Berkshire) together with Professors Igor Nabiev from Reims, in France and Vladimir Oleinikov from the Russian Academy of Sciences in Moscow used sophisticated methods of protein chemistry to attach nanocrystals to antibodies and used them to identify the molecule p-glycoprotein which is known to make cancer cells resistant to chemotherapy.

Explains Dr Bronstein:"The nanocrystals were so bright that a single molecule of p-glycoprotein on the cell surface could be detected. The challenge then was to optimise the nanocrystals for their direct application to diagnosis by using surgical biopsies. The simultaneous multicolour labeling of different cancer markers was the proof of principle step, showing that nanocrystals could be used with any type of antibody to analyse any type of molecule in cancer cells and tissues more effectively and more accurately than had been possible before".

According to Derek Napier, AICR's Chief Executive, nanotechnology could change the way we approach cancer research. "To understand the rise and progression of cancer we need a long term tracking of cells and molecules. The available existing fluorescent dyes suffer from photodegradation and can't do it. Nanotechnology is removing these obstacles and moreover, these crystals are extremely stable and fluoresce for many days. I believe this important development has opened up a new path towards more effective methods to diagnose and treat cancer in the future".

What is nanotechnology?

Over thirty years ago 20th Century Fox took the movie-going public (and Raquel Welch) on a Fantastic Voyage where through miraculous technologies, scientists shrank a 30-foot long metal ship to the size of a pinhead. Audiences were mesmerised as the miniature ship with its hero crew sailed through the bloodstream, encountering gigantic white blood cells, narrowly avoiding destruction but eventually restored to normal. It was a fantastic first step towards human dreams of shrinking medicine to microscopic size.

Nanotechnology is a catch all description of activities at the level of atoms and molecules that have applications in the real world. A nanometer is a billionth of a metre that is about 1/80,000 of the diameter of a human hair. It is a new field and offers the unprecedented opportunity to study and interact with normal and cancer cells in real time. Fluorescent nanocrystals were first developed in the United States in the late 1990's but in their original toxic form they could not have been used with any biological material - until now. Another feature of nanotechnology is that it is the one area of research and development that is truly multidisciplinary, involving collaborations with biologists, physicists and chemists.

RESEARCH OFFERS HOPE FOR NEW WAYS TO TREAT BREAST CANCER

Scientists in London have identified the master switch controlling a protein associated with the spread of breast cancer around the body. They believe their discovery could lead to more effective treatment of aggressive breast cancers, enabling them to target treatments more specifically.

The work, funded by the Association for International Cancer Research (AICR) and Breast Cancer Campaign (BCC) and published on 15th April 2005 identified how the protein HSP27 is increased in these cancer cells. Breast cancers with a higher level of this protein normally spread faster and are more resistant to current drug treatments, resulting in fewer patients surviving the disease.

A team from University College London, in collaboration with other colleagues-particularly from St Thomas's and Guy's Hospitals-found increased levels of a master switch protein called Brn-3b acted directly to make the breast cancer cells produce more HSP27. Conversely when it was removed, they registered decreased levels of HSP27. This, in turn, significantly modified the behaviour of the cancer cells, making them more likely to spread and be resistant to chemotherapy.