A large part metastatic cells out into the blood from the edges of the tumor, as from its bowels.
A malignant tumor in the initial stages of its development still holds in some borders, but sooner or later it invades the surrounding healthy tissue.
The cells of the cm. (Photo: balapagos / Flickr.com.)
On the left, tumor cells are painted green and blood vessels are colored red; right – white marked areas in the blood vessels where they penetrate the tumor cells. (Photo: Elena Deryugina, William Kiosses / The Scripps Research Institute.)”
It is believed that “budding” tumor begins in the second stage of the disease and reaches a peak in the third; in healthy tissues appear typical outgrowths of the thin elongated group of cancer cells extending from the “parent” tumor lump . But the tumor not only grows itself, it also forms metastases: cancer cells breaking away from primary tumor, travel to wander through the body, and, settling somewhere, form secondary foci of disease.
It is believed that metastases appear on the stage of active growth, and that metastasise cells are those that sit on the border of the tumor, between it and healthy tissue. However, the physicians are often faced with a situation where secondary tumors appear already when the primary tumor is by all indications not ready to metastasize. It also happens that the person removed the tumor early, and after some time, he still manifested metastases, which is like nowhere to take. Why this is so, explain in their article in Cell Reports by researchers from SCRIPPS institution of Oceanography.
Elena Deryugina and William Kiosses (William B. Kiosses) found that in fact, a malignant tumor does not always waiting for the “implementation phase” to begin to send out metastases. The researchers experimented with the cells of the cm and cancer human tumors grow in mice, but the tumor cells carried the gene for a glowing protein, so thanks to the glowing protein molecule to distinguish them from the own cells of the animal.
With the development of cancer, acquires its own blood vessels that reach to the core of the tumor. For each experimental tumor the authors built a three-dimensional map of blood vessels, and because of this, he found that the malignant cells are in the same vessels in the early stages of tumor development, and that so do even those cells that lie deep in her heart.
When the tumor began to give growths, the cells of these growths, too, began to penetrate into blood vessels, but their share was small: they accounted for less than 10% of all metastasised cells. In other words, a large part wandering cancer cells journey from the depths of the tumor, so that the metastasis does not depend on whether the tumor is implemented by processes in the surrounding tissue or does not start.
A few years ago, Elena Deryugina and her colleagues found that the blood vessels inside the tumor are different from the vessels that run along its borders: the internal is much more permeable to cells, so there is nothing surprising in the fact that most of the metastasis occurs from tumor depths – it was easier to get into the blood. (Speaking of “bowels” and “the depths”, it should be remembered that we are talking about very tiny malignancies that and see-it is not always possible.) Here, by the way, it is worth remembering about the research of Medical center employees mount Sinai, published in the end of last year, two articles about the early metastasis of breast cancer – the tumor, not having how to settle in the tissues of the breast, already sends its cells to roam the body.
All this means that when the cancer metastasized about the need to think from, not too hoping that if the tumor is removed early enough, she did not have time to scatter their malignant “seeds” throughout the body. Maybe is very useful to have a tool, the vast formation of blood vessels within tumors.
Such a drug could act on a protein called EGFR (receptor epidermal growth factor), which regulates the formation of blood vessels – according to the researchers, the protein EGFR can be fairly reliably determine how active the cancer cells to penetrate the blood vessels. However, before talking about any medication, you should understand that all kinds of tumors can metastasize at very early stages of development, or only a few.