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Human Embryonic Kidney 293 cells, also often referred to as HEK 293, HEK-293, 293 cells, or less precisely as HEK cells, are a specific cell line originally derived from human embryonic kidney cells grown in tissue culture. HEK 293 cells are very easy to grow and transfect very readily and have been widely used in cell biology research for many years. They are also used by the biotechnology industry to produce therapeutic proteins and viruses for gene therapy. == Origin == HEK 293 cells were generated in 1973 by transformation of cultures of normal human embryonic kidney cells with sheared adenovirus 5 DNA in Alex van der Eb's laboratory in Leiden, The Netherlands. The human embryonic kidney cells were obtained from a single apparently healthy fetus legally aborted under Dutch law; the identity of the mother and the reason for the abortion are no longer known. The kidney cells were originally cultured by van der Eb himself; the transformation by adenovirus was performed by Frank Graham, at that time a post-doc in van der Eb's lab, and were published in 1977 after Graham left Leiden for McMaster University in Canada. They are called HEK since they originated in Human Embryonic Kidney cultures, while the number 293 came from Graham's habit of numbering his experiments; the original HEK 293 cell clone was simply the product of his 293rd experiment. It should be noted that Graham performed the transformation a total of eight times, obtaining just one clone of cells which were cultured with some difficulty for several months. After presumably adapting to tissue culture cells from this clone finally developed into the relatively stable HEK 293 line. Subsequent analysis has shown that the transformation was brought about by an insert consisting of ~4.5 kilobases from the left arm of the viral genome, which became incorporated into human chromosome 19. For many years it was assumed that HEK 293 cells were generated by transformation of either a fibroblastic, endothelial or epithelial cell, all of which are abundant in kidneys. However, the original adenovirus transformation was very inefficient, suggesting that the cell which finally produced the HEK 293 line may have been unusual in some fashion. In fact, Graham and coworkers have provided evidence that HEK 293 cells and other human cell lines generated by adenovirus transformation of human embryonic kidney cells have many properties of immature neurons, suggesting that the adenovirus preferentially transformed a neuronal lineage cell in the original kidney culture. A very comprehensive study of the genomes and transcriptomes of HEK 293 and five derivative cell lines provides a wealth of new information about these cells. These authors also compared the HEK 293 transcriptome with that of human kidney, adrenal, pituitary and central nervous tissue. The HEK 293 pattern clearly most closely resembled that seen in adrenal cells, which have many neuronal properties. Given the location of the adrenal gland (adrenal means "next to the kidney"), a few adrenal cells could plausibly have been found in an embryonic kidney derived culture, and could be preferentially transformed by adenovirus. In fact adenovirus has been shown to transform neuronal lineage cells much more efficiently than typical human kidney epithelial cells. An embryonic adrenal precursor cell therefore seems the most likely cell of origin of the HEK 293 line. As a consequence, HEK 293 cells should not be used as an ''in Vitro'' model of typical kidney cells. HEK 293 cells have a very complex karyotype, exhibiting two or more copies of each chromosome and with a modal chromosome number of 64. They are described as hypotriploid, containing less than three times the number of chromosomes of a normal diploid human cell. Chromosomal abnormalities include a total of three copies of the X chromosome and four copies of chromosome 17 and chromosome 22. The presence of multiple X chromosomes and the lack of any trace of Y chromosome derived sequence suggest that the original fetus was female. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「HEK 293 cells」の詳細全文を読む スポンサード リンク
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