Science Cakes

Great Science Cake Off Explained – Manchester

Today we are looking back at the science cakes from the city that gave us The Stone Roses and X-Factor winner Shayne Ward. But Manchester is also home to some far greater* talent: Mancunians who can combine science and scrumptiousness in the form of #sciencecakes. We’ll see mutations, mitosis and a rather tasty looking western blot – this is the Great Science Cake Off Manchester.

There is a lot going on at the Manchester Cancer Research Centre where Cancer Research UKThe Christie and The University of Manchester have joined forces to build new facilities – opening next year – to enable world leading cancer research into the treatment and diagnosis of this disease. Researchers are working hard to understand the biology behind how a cell becomes cancerous, how drug resistance occurs and are also focusing on a number of cancers such as breast and lung cancer.

Dedicated scientists in Manchester’s Drug Discovery Centre are  discovering and developing new drugs to make sure this research is used to give us all More Tomorrows, whilst other researchers are exploring new ways to use radiation and imaging in cancer treatment. Manchester is also special as it is also home The Christie’s Clinical Trials Unit which is one of the largest clinical trials units in the world. Let’s see what cakes…

mitosis is

Mitosis is…

The first cake from Manchester shows what happens inside a cell when it divides. Researchers have to understand cell division as when a cell becomes cancerous they start to divide out of control and this is how a tumour can form.

Most cells in the human body divide by mitosis, where a single cell makes a copy of all its DNA (and everything else in the cell) then divides into two identical cells each with their own set of information.

Human cells all have 23 chromosomes, into which all our genetic information is packaged, you might know about the X and Y chromosomes that make a men different from women – ladies have two X chromosomes (XX) whilst men have one of each (XY). On this cake the chromosomes are shown in blue. When the DNA is copied before cell division each chromosome will have a identical partner that it will line up with. Special fibres called “spindles” (shown in red) attach to the chromosomes to help them line up along the equator of the cell. This process is all organised by the centrosomes (shown in green) which together act like the foreman on a building site to ensure the cell division happens as planned. The cake also shows a little more detail where the spindle fibres attach to the chromosomes, the little yellow dots are called centromeres.

When the cell is ready to divide the spindle fibres drags one of each chromosome pair to opposite poles of the cell towards the green centrosomes. The cell membrane (chocolate fingers) then close in at the equator eventually separating the two halves of the cell which now both have everything they need to start the process all over again. Unfortunately for this cake it cannot divide and make two new cakes but it is a brilliant entry.

guess 2

Can you find the mutation? Disclaimer: the cake has already been eaten so you cannot win it but I understand it was very tasty.

The next cake is looking at the DNA sequence. It is a puzzle where you have to find the difference between two pieces of DNA code. DNA is like a language – it can be read by machinery in the cell to produce proteins – but unlike English, which uses 26 characters, the DNA language has 4 “nucleotides” which scientists named A, C, G and T. These letters stand for Adenine Cytosine Guanine and Thymine. Incredibly, everything that we are is made from a sequences of A, C, G and Ts and it is subtle differences in the code that means some people have blue eyes whilst others have brown.

Our cells are reliant on the information in the DNA in order to function properly and if this code is changed it can have some severe consequences. For instance, consider what would happen is where someone has replaced the word sugar for salt in a cake recipe. This is what happens in cancer and we call changes to the DNA mutations.

Mutations happen naturally, albeit not very often, when a cell divides but other things like UV radiation from the sun and chemicals that are in cigarettes can also increase our risk of getting mutations (you can read about what causes cancer on the CRUK website). Over time mutations add up until the cell starts misbehaving and can start to grown out of control.

Scientists are trying to understand mutations in cancer so we can detect cancer early and target cancer cells without damaging normal cells.

TMA

Tissue MicroArray cake

Next, onto a Tissue MicroArray (TMA) cake. Scientists use cancer tissue to better understand how a tumour has formed. Tissue samples are preserved in a special wax, cut into very fine sections, and then used for diagnosis or look for the differences between normal and cancer tissue. However, looking at each tissue sample one at a time can be very time consuming so when tissue is used for research lots of tiny sections of different tissue are embedded into a wax section side by side. This means when the TMA is cut into thin sections there are dots of many different tissue samples on one slide.

The cake shows what a TMA looks like; the cake base is the wax and the cookies represent lots of different tumour samples that can now be analysed at the same time.

Western Blot

Western blot lab equipment

Finally some rather tasty lab equipment, this is a western blot cake. Western blot is a technique that scientists use to compare the proteins found in normal and cancer cells. Scientists can take cancer cells, break open the cell membrane and collect the contents to investigate them further.

The western blot equipment is shown here; the black cake is a power supply with an on/off button, and the science happens in the green topped “tank” that is connected to the power by two leads. The most important part of the western blot tank is a gel (a kind of jelly like substance) that sits in a liquid buffer.

Protein samples – that are collected from cells – are combined with a dye that attaches to the protein and makes it negatively charged. In this set up, the positive current would be at the bottom of the tank and the proteins would be attracted to that positive change and forced to travel downwards through the gel.

The proteins in a cells come in all shapes and sizes. In this experiment larger proteins find it harder to move through the gel whilst the smaller proteins can move through faster. This means, by the end of the experiment, the smaller proteins end up at the bottom of the gel, medium sized proteins get about halfway down, and large proteins are still at the top. Sorting proteins by size in this way helps scientists to identify them later and it also helps to compare the different proteins that are present in the different samples. As you can see in this cake the lanes appear to have different proteins in as the blue “bands” appear at different positions in the gel.

Some great science cakes covering cell biology, techniques and even lab equipment from Manchester. This blog will continue as we look at the entries from CRUK centres in Birmingham, Glasgow, London, East Scotland, Cardiff, and Southampton delving further into the weird and wonderful world of cancer biology. Can’t wait for the next post? You can view all the cakes in the 2013 Great Science Cake Off on Pinterest.

@Beckieport is a CRUK funded PhD student in the final stages of her doctorate studying how viruses cause cancer. If you want to know more about the research and events happening at the CRUK centre in Manchester you can follow Eve (the research engagement manager) on twitter, @CRUKManchester, or find out more about their world class research on the More Tomorrows website. As always comments and suggestions on this blog are encouraged. This is a personal blog and is not endorsed by CRUK – however I hope you like it anyway.

* the statement that #sciencecake baking requires more talent than making music has not been rigorously scientifically tested. More repeats are required to ensure statistical significance.

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