How cancer grows and spreads - Getting the wrong message

Hormones are chemical 'messengers' produced by the body - they send messages that control the growth and activities of different types of cells.

We have known for many years that they can influence the growth of certain cancers. For example, the female sex hormone oestrogen can fuel the growth of breast cancer, while its male equivalent, testosterone, drives prostate cancer growth.

Blocking the effects of sex hormones is an important way to treat these diseases, and back in the 1930s and 40s our scientists developed some of the first artificial hormone treatments for breast and prostate cancer.

Although hormone treatments are often very effective at controlling these cancers, over time the cells can become resistant and start to grow again, so the cancer comes back. Our scientists are at the cutting edge of research into this problem, developing better treatments that will save more lives.

At our Cambridge Research Institute, Dr Jason Carroll is investigating how breast cancer cells become resistant to the commonly-used drug tamoxifen, which blocks the actions of oestrogen. In the same building, Professor David Neal is developing ways to target prostate cancer cells that have become resistant to hormone therapy. 

Meanwhile at Imperial College, London, Professor Charles Coombes is developing and testing new drugs for breast cancer. He hopes these will overcome the problem of hormone resistance and improve long-term survival for many women with the disease. And we were involved in the early development of a new prostate cancer drug called abiraterone, which blocks the production of testosterone.

Growth factors are another important group of messengers in the body that tell cells to grow and divide, or to stop dividing. If there are too many growth factor molecules - or if cells respond over-enthusiastically to them – the cells can start to divide out of control, leading to cancer.

Cancer Research UK scientists are at the forefront of research into growth factors and their role in cancer.

At our London Research Institute, Dr Caroline Hill is investigating an important growth factor called TGF beta. This normally tells cells to stop dividing, but the signalling process is faulty in cancer cells, so they keep on growing. But as the cancer develops and grows, TGF beta 'changes sides', fuelling fuel the growth of cancer cells.

Dr Hill and her team are working to understand TGF beta’s ‘split personality’, and how its messages are interpreted by cells. And because it is faulty in several different types of cancer, finding ways to target TFG beta could lead to important new treatments for the disease.

Another group of signals implicated in cancer is the ‘insulin-like growth factors’, or IGFs. Cancer Research UK scientists have made great progress in understanding how IGFs act on cancer cells, and how we can use this knowledge to tackle cancer.

At the University of Oxford, Professor Bass Hassan is developing ‘molecular handcuffs’ to mop up excess IGFs, preventing them from acting on tumours. And at the University of Bristol, Professor Richard Martin is investigating how IGFs are involved in prostate cancer.

Hormones and growth factors are examples of signals that allow cells to 'talk' to each other. But equally important are the ‘gateways’ – known as receptors – that receive the signals, and the ‘messengers’ that transmit information within cells. There are many different receptors and messengers, and we know that a large number of them are faulty in cancer.

Research into receptors has led to the development of important new cancer treatments. For example, our work on certain receptors found on the surface of breast cancer cells helped lay the foundations for the drug Herceptin (trastuzumab).

Cancer Research UK-funded scientists also helped to discover that an internal messenger protein, called BRAF, is faulty in many cancers - including more than half of all melanomas. Scientists are now working on agents that block faulty BRAF, which could be potent cancer drugs in the future.

Many messengers inside cells are proteins known as kinases. These work by sticking chemical ‘flags’ onto other messengers. Kinases are often overactive or damaged in cancer cells, so important messages get sent too often or not at all.

At The Institute of Cancer Research in Sutton, Professor Paul Workman is testing drugs that block a signalling molecule called PI3 kinase. This normally sends signals inside cells telling them to divide and is overactive in many cancers. Blocking it stops the signals, so the cancer cells stop growing. 

Watch a video of Professor Workman talking about the new drugs he and his team are developing:

And at our London Research Institute, Professor Peter Parker is studying a different type of kinase called PKC, which is also often overactive in cancer. He is investigating how PKC and other messengers are ‘wired up’ within the cell, and working on ways to target them with new drugs.