Can Stem Cell Behaviour Be Predicted?
Can Stem Cell Behavior Be Predicted? Could we gain enough understanding of the cell differentation process to be able to control it? Build cells on demand? Build organs and tissues on demand? Finally cure Parkinson and Cancer?
In November 2008 I was able to finally defend my master thesis on image processing and bioelectronics at the university of Linköping and OBOE. Its main goal was to find out whether stem cell behaviour could be predicted by studying its morphology. I ended up building a system to analyze cell morphology whose core was a MATLAB graphic interface application and a set of image segmentation algorithms. For those who find biology and image processing interesting here you can find a brief excerpt from the documentation I wrote, as well as the full writings to download.
Understanding life has always been one of the main interests of mankind. Since the beginning of times, human-being has questioned himself about the mechanisms of his own existence and through the ages has unveiled some of the mysteries that surround life on earth leading to the discovery of the cell, the basic component of every living creature. From the smallest and simplest single-cellular beings to the most complex organisms like the human-being – a compound of millions of cells interacting, communicating and performing an infinite number of different tasks – all living creature share this basis in common. It seems natural then, the importance of seeking a better and deeper understanding of its characteristics and behavior.
The greatest achievements in biology research have been made during the last century. Starting in 1838 with the postulation of cell theory, that is, that every living organism is built of cells, a number of startling breakthroughs have soon followed: the isolation of DNA, the chromosome theory of heredity, the discovery of DNA’s double helix structure, the success in cloning and the draft of human genome are just some examples. All this newly acquired knowledge has cleared the present path of research into two principal ways leading the efforts of scientists throughout the world into the research of human genome – the biological ‘code’ that defines the human-being as it is – and stem cells – cells with the extraordinary capability of dividing indefinitely and differentiate in order to become any kind of tissue in human body. It is in this last field in which the current project has its use and purpose.
Stem cells can be divided into two big groups or categories, “embryonic” and “adult”. ES cells, also called “pluripotent”, are created in the human embryo and have the capacity to grow in culture indefinitely and to differentiate into all tissues in human body. Adult stem cells, on the other hand, are contained in several tissues in the adult human body and have similar characteristics to ES cells but being able to differentiate only in a range of specific tissues – this is the reason why they are given the name of “multipotent”. Due to this special features these kind of cells posses, scientists have started to experiment with them in order to create human cells and tissues on demand. The advantages and possibilities of this practice are huge and have a wide area of application: neural cells to repair damaged brains, muscular tissues and organs for transplants, etc. Present studies pursue the understanding of the process of differentiation, trying to discover which factors trigger the behavior of cells in one way or another. Although different stem cells behave in different ways, the experimenting process usually follows the same general steps: During the first stage the stem cells are isolated from the embryo or adult specimen and stored in a controlled media. Then a growth factor is applied to them so they
won’t differentiate but will start dividing and growing in number to become a colony. Finally a number of chemical stimulations are used to induce the cells to differentiate. The whole process is controlled using powerful microscopes which take images from the cell colonies in certain periods of time, building time-lapse sequences – sequences of images with low frequency sampling that allow to see long-term changes – being of the highest importance to identify and track cells in order to obtain the biggest amount of information.
Staining is the most usual method used for marking, tracking and identifying cells, but applying it usually results in the death of most of the cell colony, hence, new methods less aggressive would be most welcome. It is here where computer science finds its application through the field of Image processing. The huge calculation power of computers allows to apply complex algorithms on time-lapse sequences successfully marking and tracking cells. But can cells be identified by their morphological features? And moreover, can the differentiation process be divided into several stages according to cell morphology changes? These are the main questions the cell morphology project tries to find an answer for, and the main focus of this research.
Quite interesting topic indeed…