The highest honor given by the Society for In Vitro Biology
is the Lifetime Achievement Award. It is presented to scientists
who are considered pioneers or highly influential researchers
to the science and art of cell culture. They are men and women
who have devoted their careers to exemplary research and/or
teaching. The recipients of the Lifetime Achievement Award
are selected by vote of the Board of Directors from a list
of nominations received and recommendation by the Awards Chair.
Eugene Elmore was the chairperson for 2004.
The Lifetime Achievement Award was presented to three scientists
at the 2004 SIVB World Congress in San Francisco, California.
The Awardees were Dr. Thomas Grace,Prof. Sangyin Gao, Dr.
Walter Nelson-Rees, and Dr. Trevor Thorpe. Over the next issues
of In Vitro Report, each of the winners will be highlighted
with an article written by those who prepared the nomination.
Walter Nelson-Rees holds a most distinguished place in the
history of tissue culture for his role in exposing the problem
of cross-contamination of cell lines. This story began in 1952
when George Gey produced the first continuous human cell line,
HeLa, derived from a cancer of the uterine cervix in an African-American
woman. He distributed the HeLa line widely to other investigators
for use in their research. Shortly thereafter, many scientists
seemed to suddenly be able to grow human cells long-term, and
began publishing descriptions of continuous human cell lines
originating from both malignant and normal tissues. This was
somewhat puzzling because it was not easy then, and it continues
to be very difficult to establish a cell line from a human cancer.
Furthermore, normal cells of human origin almost never spontaneously
transform and grow in long-term culture. The explanation for
this surge of success in establishing human cell lines began
to emerge by the early 1960s through routine karyotyping. Many
cell lines were shown to be of a different species from the
donor from which they originated. For example, some monkey cell
lines turned out to be human and some human cells were shown
to have a mouse karyotype.
Dr. Nelson-Rees accepts the 2004
Lifetime Achievement Award
However, routine karyotyping could not distinguish among cell
lines derived from individuals of the same species. In 1967
that Stanley Gartler applied the concept of biochemical polymorphism
to begin to solve this problem. Some proteins have a number
of different forms (isoenzymes), and these forms can differ
genetically among individuals. The American Type Culture Collection
(ATCC), which was set up to collect "authentic cell cultures,"
along with several other sources, supplied Stan Gartler with
18 supposedly unique human cell lines, and he found that all
these cell lines had the less common A form of the isoenzyme,
glucose-6-phosphate dehydrogenase (G6PD), the form found in
HeLa cells, and a form common in people of African descent and
rare in people of European descent (1).
But it was not until 1975, that the full extent of the problem
was revealed. While many scientists were not able or did not
want to see the importance of Gartler's work, Walter Nelson-Rees
not only recognized its significance, but also confirmed and
extended Gartler's findings. At that time, Nelson-Rees was co-director
of the Cell Culture Laboratory at the Naval Biosciences Laboratory,
Oakland, CA. This laboratory was under the auspices of the University
of California at Berkeley and was funded by NIH. The facility
collected and distributed cell lines worldwide and under Walter's
direction maintained the most rigorous standards of quality
control achievable at that time.
Applying a new karyotyping method, Giemsa banding, Walter found
that the HeLa cell line had several unique marker chromosomes
not found in the normal complement of human chromosomes. He
identified these chromosomes in over 40 cell lines. In each
of these lines only the A form of G6PD was present, even though
the majority of the donors of origin were Caucasian and would
be expected to have the B, not the A, isoenzyme of G6PD. Nelson-Rees's
work was published in a series of 11 papers, 5 of which were
in the premier journal Science (2-12).
Acting on his peer-reviewed, scientific results, Dr. Nelson-Rees
rightfully took advantage of every opportunity to make scientists
aware of the problem of intra-species cross contamination of
cell lines. His efforts were often met with great skepticism
and resistance, especially among some scientists whose cell
lines were shown to have the chromosome markers typical of HeLa
cells. It was understandably difficult for them to accept the
invalidation of years of research and the loss of thousands
of research dollars. Some scientists, however, when notified
that the cell line they had developed was really HeLa, accepted
the news with dignity, and responsibly relayed the news to scientists
to whom they had distributed the cells. This chain of events
was important in preventing further inappropriate use of these
The methods of DNA fingerprinting developed in the 1980s, and
DNA profiling such as STR, developed in the1990s, have provided
unequivocal confirmation of Walter's work and extended further
the sensitivity of methods available to detect cell contaminations
(13). STR (short tandem repeat) profiling provides an international
reference standard for human cell lines (13). Because it tests
several genetic loci that are commonly polymorphic, the chances
of any two lines having exactly the same "fingerprint"
by chance are minute and this method is extremely robust for
detecting cell line contamination.
Unfortunately Walter Nelson-Rees retired at the height of his
renown in 1980 after publishing nearly 70 full-length, peer-reviewed
article. Perhaps due to the absence of his vigilante efforts
or to lack of awareness of a new generation of tissue culturists,
quality control in general, has slipped, and today it is estimated
that about 20% of all cell lines have a false identity (14).
There is widespread intraspecies cross-contamination of cell
lines, due mostly to contamination among human cell lines (14).
While the offending contaminant is still most commonly HeLa
cells, e.g. the contaminant lines KB, HEp-2, WISH, Girardi heart,
Chang liver, and Intestine 407, some other transformed human
cell lines have now also been identified as playing this role.
In many instances, the cell line being used may not matter if
one is studying biochemical pathways and the cell serves only
as a "bag" to hold the molecules. But where conclusions
about tissue specific activities are being drawn, e.g. receptors
for viruses, products of differentiation, the conclusions could
be completely invalid if the incorrect tissue type were used.
Such is the case for a large number of published projects where
HeLa contaminated cell lines were employed.
The legacy of Walter Nelson-Rees to tissue culture is as relevant
and important today as when he retired. If all tissue culture
laboratories met his standards of quality control, the problem
of cross-contamination would rapidly disappear. The work of
Walter Nelson-Rees exposed an enormous quantity of flawed research,
and helped to prevent these cell lines from being used inappropriately
by other scientists. The hypotheses underlying his vision and
his cell culture practice have been unquestionably proven by
modern molecular methods, and it is timely that his contributions
should be recognized by the SIVB.
John Masters, PhD