Afinal, o que são células-tronco? | #InstanteBiotec 04

The use of stem cells in research and medicine is a very debated subject. But after all, what are these cells? Stem cells are precursor cells that can divide to produce more of the same or other differentiated cells, as skin, bone and blood cells.

The general characteristics of a stem cell are: capacity for self-renewal, in which the cell can divide by mitosis extensively. So we can obtain, in vitro, a culture with clones of this first stem cell to continue dividing. On the other hand, somatic cells, in vitro, would not pass 80 divisions.

Today, we have established stem cell lines we can acquire and work with them in the search without isolating them from new embryos. Yes, stem cells of embryonic type are cells DERIVED from the inner cell mass of blastocysts, i. e.

from embryos. Thus, they can leave the not specialized state to differentiate in all cell types found in an adult organism. So they are called pluripotent.

They are not totipotent cells as the zygote is, which is able to generate a complete organism, including embryonic annexes. Adult stem cells are also cells capable of self renewing and differentiating but in a more limited number of cell types, they are multipotent. Such stem cells are found with already differentiated cells in tissues and organs, which they are helping to keep and repair them.

Examples include neural stem cells, that can generate neurons and glial cells; and also hematopoietic stem cells that will generate white, red and other blood cells. Those cells that give rise to only one cell type are called progenitor cells. There is still another type of stem cell, induced, or iPS.

These are adult cells that have been genetically reprogrammed and have returned to the least differentiated stage. Through induction of gene expression and specific factors they become pluripotent and are able to originate cells from the three germ layers: ectoderm, mesoderm, and endoderm. They are also being studied possible cancer stem cell.

They have the same properties of self renewal, i. e. , proliferation, and differentiation of other stem cells.

Thus, they would be able to generate tumor cells. Their existence would also explain how tumors may recur even after treatment. These different types of stem cells can be identified by their gene expression profile.

They may also have different surface markers that facilitate this distinction. So, it is important to determine which genes are related to stem cell state. And then establish a molecular fingerprint.

Knowing this molecular fingerprint, in case of cancer stem cells, we could identify them more easily so they could be target of therapies, and then, it could be possible to completely destroy the tumors. preventing them from recur.