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Lack of Genetic Diversity in Common Cancer Cell Lines

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Key Points

  • All previously classified white cell lines were accurately described with average European ancestry of 97%, whereas cell lines classified as African American were not always accurately described and were of more mixed genetic ancestral background.
  • Researchers discovered that E006AA-hT(characterized as of African American origin and used to study prostate cancer disparities, among other research goals) is predominately of European ancestry (91%) and may actually be a case of kidney cancer, not prostate cancer. That leaves the cell line MDA-PCa-2b as the only commercially available African American prostate cancer cell line.
  • “Entire demographics are ignored in key mechanistic studies hindered by the restraints monoethnic cellular models afford,” the study stated.

Researchers have found that some commercial cancer cell lines used for laboratory studies have mislabeled ancestry when it comes to minorities. These findings were published by Hooker et al in Cancer Epidemiology, Biomarkers & Prevention.

“A lack of diversity is prevalent in every level of biomedicine—from the patient population in clinical trials to the donated samples for scientific investigation,” said Rick A. Kittles, PhD, Director of the Division of Health Equities at City of Hope and senior author of the study, in a statement. “How can we expect to narrow the health equity canyon when our basic scientific resources—cell lines for laboratory study—is predominately from people of European ancestry? Minorities like myself are not the primary beneficiaries of most scientific innovations.”

Study Methods and Findings

The study looked at 15 commercial cell lines used to study prostate, breast, and cervical cancers. The cell lines were categorized based on their amount of West African, Native American, and European genetic ancestry. All previously classified white cell lines were accurately described with average European ancestry of 97%, whereas cell lines classified as African American were not always accurately described and were of more mixed genetic ancestral background.

Of note, many scientists who investigate prostate cancer health disparities have used a cell line called E006AA-hT, which is characterized as of African American origin. Yet, the researchers discovered that E006AA-hT is predominately of European ancestry (91%) and may actually be a case of kidney cancer, not prostate cancer. That leaves the cell line MDA-PCa-2b as the only commercially available African American prostate cancer cell line, Dr. Kittles said.

“This mislabeling may elicit memories of a time in the United States when African Americans were identified as black if they had any noticeable amount of African American ancestry in their skin color,” Kittles said.

Researchers also searched the American Type Culture Collection website for cell lines derived from normal and malignant breast tissue. They found that 71% of the specimens were classified as white, whereas 13% were designated as African American. There was only one Hispanic and one East Indian sample.

“Entire demographics are ignored in key mechanistic studies hindered by the restraints monoethnic cellular models afford,” the study stated. “This is problematic as underrepresented racial/ethnic groups, who are more likely to suffer disproportionate disease incidence and mortality, remain also underrepresented in biospecimens available for research.”

Suggested Methods of Improvement

Genetic ancestry estimates offer more sophisticated characterization that could lead to improved disease prevention and treatment protocols. As a result, Dr. Kittles and his colleagues suggested using a standard set of 105 established ancestry informative markers to validate ancestry in order to make headway in precision medicine for all.

“An important aspect of precision medicine is being able to leverage the genetic background of individuals for disease risk assessment, stratification, prognosis, and outcome,” Dr. Kittles said. “Here we show that what many investigators thought were classic samples from racially defined individuals wasn’t the case.”

To make precision medicine precise for people of all ethnicities, diverse biospecimens are required, Dr. Kittles said. These biospecimens should undergo robust characterization so that their genetic ancestry is accurately reflected, he added.

Disclosure: This study was funded by the National Institutes of Health. The study authors' full disclosures can be found at cepb.aacrjournals.org.

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.


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