Growing cancer cells gives me a tool to investigate how cancer forms. I give cancer cells DNA damage and see how they respond. This is important because a lot of cancer treatments rely on killing cancer cells by giving them more DNA damage than they can cope with.
Excellent question! Mostly, I grow cancer cells called ‘cell lines’ – these are cells which have originally been taken from a person with cancer (sometimes decades ago) and have either been found to spontaneously grow under laboratory conditions, or been altered genetically so that they will. Most people’s cancer cells will only grow for a little while in the lab before dying. I study how cancer cells acquire damage to their DNA – so sometimes I will expose them to things which cause DNA damage, such as chemicals found in cigarette smoke. However often, I just let them grow for a long time – up to a few months and then i look and see what DNA mutations they have. Cancer cells are intrinsically what we would call ‘genetically unstable’ meaning that they are normally far more prone to having damaged DNA than normal cells – this is often because they can’t repair the damaged DNA as well as normal cells can. So, in summary, cancer reseachers grow cancer cells for lots of reasons – sometimes to test new drugs or in my case, to understand why people get cancer in the first place.