Leukemia: Can Jump Over of Mother on Child
October 13th 2009 -
Cancer cells can be transferred during the pregnancy to the unborn child. Which was already longer assumed, Japanese researchers could occupy now for the first time on the basis genetic investigations: They examined tumor cells of a baby and found out that these resembled the maternal in certain gene sections so much that they obviously developed in the maternal body and over-jumped afterwards on the fetus. To the childlike cells was missing besides a certain surface protein, whereby they became invisible for the immune system, so that they could inclusively-calibrate themselves unnoticed into the body. With the mother these proteins had been still available, like Takeshi Isoda of the university of Tokyo and its colleagues in the specialist journal “PNAS” report.
The so far only possibility of assigning cancer cells to its forerunners clearly is the so-called genetic Fingerprinting. The researchers determine the DNA sequence of the cancer cell in several places and manufacture thereby a cell profile, which is as individual as a fingerprint. If they compare with it then the profile of another cell, they can determine the relationship of the two cells with a very large probability. With this method they compared cells, which had won them from a tumor at the jaw eleven of a months old infant, with maternal cells. With the mother shortly after the birth a leukemia had been determined.
The analysis resulted in that the genetic make-up was in the very most tumor cells of the child not a mixture from paternal and maternal DNA, as in the case of all other somatic cells. Rather the tumor cell DNA agreed practically with the maternal. From the fact the researchers conclude that the tumor of the child had his origin in the body of the mother and to the child to transfer became. The fact that cancer can be sticking on perhaps is already longer well-known. The fact that this infection happens however over the Placenta is extremely rare, writes the researchers. This barrier normally prevents together with the immune system an infection of mother on child.
But can obviously be expenditure-cheated also the immune system. Thus an important component of the cell surface with the childlike tumor cells, which had been still present with the mother, was missing: the so-called maternal HLA alleles. HLA alleles mark all body-own cells and protect them before the own immune system. They would have arranged the immune system of the child to attack the cancer cells simply because the maternal HLA alleles would have marked it as strange – independently of it whether it concerns cancer cells. But since the maternal HLA alleles were deleted, the immune system of the child did not have a possibility of recognizing the maternal tumor cells as strange. The loss of the HLA alleles is probably one of the strategies, with which cancer cells arrive of a body into another, closes the researchers.
Tags: cells, DNA, immune system, Leukemia
