06. 2010 | Cell Line Identification: The Beginning of the End | Read Full Article
Cell lines are used extensively in biomedical research as in vitro models. The validity of the data obtained often depends on the identity of the cell line, particularly when it is being used as a surrogate for the tissue of origin. Surprisingly, the frequency of cell line misidentification is high, and consequently the ascribed origin of a cell line is often incorrect. This problem has been known for over 50 years and has been described as the most compelling quality-control issue confronting the scientific community. Based on analyses of cell lines submitted to international cell banks, the incidence of misidentification in 1977 was 16%2 and in 1999 was 18%3. Until recently, the authenticity of cell lines used in biomedical research has received little attention. This Science and Society article has been written by the members of the American Type Culture Collection (ATCC) Standards Development organization (SDo) workgroup ASn-0002(BOX 1), a working group currently developing a standard for human cell line authentication. The ATCC SDo was formed in 2007 to develop best practices (standards) for use in the life sciences and to promote their use globally, using a consensus-driven process that balances the viewpoints of industry, government, regulatory agencies and academia. we expect that the draft standard (BOX 2) will be available for public review and comment in 2010 and subsequently the final draft will be approved by the American national Standards Institute (AnSI).
Here we describe the causes and scientific effects of cell line misidentification, its history and the efforts taken to solve the problem. The various methods currently available for authenticating cell lines are discussed and a recommendation is made for the use of short tandem repeat (STr) profiling for authenticating human cell lines. Perhaps of the greatest importance, a universal database of human cell line STr profiles is under construction.
Discovery of cell line misidentification: Misidentification of human and animal cell cultures is a long-standing problem, and awareness of this problem dates back to the 1950s (TIMeLINe). Karyotyping and immunological approaches were first used for cell line authentication. extensive species misidentification was reported, leading to the establishment of a bank of authenticated cell lines at the ATCC in 1962.
Misidentification within species could not be detected in 1962, but in 1966 Stanley Gartler (FIG. 1a) introduced the concept of biochemical polymorphisms to distinguish human cell lines on the basis of their isozyme expression. At the Second Decennial review Conference on Cell, Tissue and organ Culture in 1966, Gartler reported that 18 human cell lines supposedly of independent origins were all HeLa cells, the first human cancer cell line to be established in culture. The examples included cells claimed to be derived from normal intestinal epithelium (Int-407), normal amnion (wISH), normal liver (Chang liver), laryngeal cancer (Hep-2) and oral cancer (KB). The HeLa cell line was derived from a glandular cervical cancer in a female patient named Henrietta Lacks and, because of its celebrated status, was distributed internationally and passed from laboratory to laboratory. Then, as today, many scientists were oblivious to the possibility of crosscontamination. HeLa cells are particularly robust and fast-growing and consequently can rapidly overgrow other cells.