University years

Can we reprogram cells?

I reached my third and final year of the bachelor in October 2012. Finally, I was putting together all the pieces of the previous two years courses and I started applying all the basic biological knowledge (Chemistry, Biochemistry, Molecular Biology and so on) to the more specialistic courses, as it was Physical Chemistry (the study of how matter behaves on a molecular and atomic level and how chemical reactions occur, in order to understand some analytical techniques used in Molecular Biology as well) and Enzimology (the study of enzymes, their kinetics, structure, and function, as well as their relation to each other).


Among the other courses we had in that third year first semester, there was Developmental and Stem Cell Biology. Sometimes the destiny or case comes into play and that year the Nobel prize for Medicine and Physiology was awarded to two scientists that spent their lives working on stem cells, or better, in reprogramming cells, for example a cell from the skin, so that it can “go back in time” to a moment where it was still able to become whichever type of cell they wanted. I do not know if it was because Sir John B. Gurdon and Shinya Yamanaka received the Nobel “for the discovery that mature cells can be reprogrammed to become pluripotent”, but studying the stem cells while the two scientists that discovered how to bring back in time mature cells to an undifferentiated state amazed me very much. Moreover, when I talked to my mother about the in vitro fecundation techniques we were studying in the developmental part of the lectures, she told me that I was actually an in vitro baby: it was at the same time very fascinating and weird studying the techniques that made my life being possible!

There are so many things that I would like to write on this course, as for example the sex determination and all the changes that happen in an organism that is developing when there are the male XY chromosomes rather than the female XX ones; stem cells and the differences between the embryonic and somatic ones; the reprogramming of mature cells into undifferentiated ones and their current and future uses for medicine and medical engineering. However, since in the end I managed to actually join that lab for my Bachelor thesis and I had to write a literature review on a new ex vivo material for oocytes maturation, I guess I will talk about the developmental part of this course later. For now, for the SRF, I will just talk about the two scientists won the Nobel prize back in 2012 and made me chose the Developmental and Stem Cells laboratory for my Bachelor thesis.

So let’s start from the beginning: the English biologist John B. Gordon is unanimously recognised as a pioneer in the research of the stem cells. Already in 1962 he discovered by working on frogs that the cell specialization (as it might be the specialization of a skin in the skin) is a reversible process, changing one of the Developmental Biology dogma, the unidirectionality of specialization. He inserted the nucleus of an adult and mature intestinal frog cell into an immature egg cell (deprived of its original nucleus). This modified egg then developed in a normal tadpole (see schematic below).

Schematic of Sir Gurdon’s research. Modified from nobelprize.org

Forty years later, Shinya Yamanaka demonstrated how mature mouse cells can be reprogrammed back to immature stem cells. The astonishing thing of its research was the fact that he had to insert only few genes to reprogram mature cells into pluripotent stem cells, then able to differentiate themselves in all the cells of the organism. He identified these genes able to maintain stem cells in vitro in their pluripotency state and he managed to use these same genes to reprogram mature and specialized cells into pluripotent and undifferentiated ones, that he named induced pluripotent stem cells (see schematic below).

Schematic of Dr. Yamanaka’s research. Modified from nobelprize.org

Their incredibly discoveries have revolutionised our understanding of how cells and organisms develop. In these years, research has shown that, using the right mix of genes, this induced pluripotent stem cells can develop into all the different cell types of the body. Their pioneeristic researches have also provided new tools for scientists around the world and led to remarkable progress in many areas of medicine: for example, skin cells can be obtained from patients, reprogrammed, and examined in the laboratory to determine their differences with the cells from healthy individuals. These induced pluripotent stem cells are a precious tool that can be used to understand disease mechanisms and to develop new medical therapies (see schematic below).

Schematic of possible uses of induced pluripotent stem cells. From nobelprize.org

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