DNA-lab “Reading the tumour”

Isolate DNA and compare DNA from tumour cells with that of healthy cells using a PCR-reaction. Provide advice on the best treatment for the tumour.

The cause of cancer is damaged DNA. Mutations that occur in the DNA can lead to uncontrolled cell division and finally to the development of a tumour.

Cancer type

What is the best way to treat cancer? What about spreading of tumour cells? How does cancer arise? Is cancer hereditary? These are questions that a patient wil ask a doctor. To choose the right treatment, the doctor needs to know what type of cancer it is. Because the origin of cancer lies in the DNA, doctors will call on DNA-researchers for help. The researchers get a small piece of the tissue of the tumour to study the specific properties of that tumour. As it turns out, different patients often have different combinations of mistakes in the DNA of their tumours. Using this information, the doctor can determine a targeted treatment that offers the best chances for that particular patient.

Medical advice

In this DNA-lab, the students will be real DNA-researchers. A doctor asks them to perform the DNA-research on one of his patients. It is up to the students to determine which mistakes are present in the DNA of the patient’s tumour cells and to use that information to provide advice on the most effective treatment.

Techniques

To illustrate the topic, the students will be shown a piece of animal gut tissue containing tumours and metastasis. The students will subsequently isolate DNA from a piece of cow thymus. This allows them to actually ‘see’ and ‘feel’ real DNA. To answer the doctor’s questions, they will compare the DNA from the tumour with DNA from healthy cells using the PCR-technique and gel-electrophoresis.

Context

This DNA-lab brings together a number of biological concepts. The students will see that topics such as DNA, heredity, mitosis and meiosis, and the building, growth and development of cells are important to answer questions concerning cancer. Can I prevent cancer? Which treatments are possible? Is cancer hereditary? The students will tackle these questions after the practical work. They will realise that they already possess a lot of knowledge relevant to these questions. Cancer is not only a very awful disease, but also a biological phenomenon with a clear message: Take care of your DNA!

Required knowledge

It is advisable that the students are familiar with certain concepts beforehand.

This DNA-labs shows that a healthy cell can turn into a cancer cell when certain genes, necessary for normal cell function, are damaged. Uncontrolled division of such a cell leads to the formation of a tumour that in turn can spread throughout the body.

Specific knowledge of cancer is not required. To understand this DNA-lab, the students should possess elementary knowledge on cell biology and molecular genetics. The students should be familiar with concepts such as DNA, gene, chromosome, heredity and genotype - phenotype. They should know that one gene codes for one protein, which in turn has a specific function in the cell. The construction of a cell and the cell division processes, mitosis and meiosis, should also be familiar to the students.

The lessons on cells, DNA and heredity from the regular curriculum provide a good basis for this DNA-lab.

This DNA-lab can be used in biology lessons.