ATLANTA — Parabens, a class of endocrine-disrupting chemicals widely found in hair and personal care products, promote viability and gene expression of a breast cancer cell line in Black women, according to data presented at ENDO 2022.
Researchers evaluated the effects of three types of parabens in the HCC1500 breast cancer cell line, which is typically found in Black women of West African ancestry, and compared the effects with those observed in the MCF-7 cell line, typically found in white women of European ancestry.
“The HCC1500 breast cancer cell line may be more sensitive to parabens,” Lindsey S. Treviño, PhD, assistant professor in the division of health equities, department of population sciences at City of Hope National Medical Center in Los Angeles, said in a press conference. “We have two lines of evidence for that. Butylparaben increases the cell viability of HCC1500, but not MCF-7, and the increase in the estrogen-regulating gene expression is more robust in the HCC1500 cells treated with butylparaben or propylparaben.”
Parabens are common endocrine-disrupting chemicals used in cosmetic and personal care products. They are detected in nearly all urine samples taken from adults, according to Treviño, and act similar to estrogen in the body. Although prior studies have shown parabens can impact breast cancer cell proliferation, mortality, migration, metabolism and gene expression, Treviño said those studies were done using cell lines of women with European ancestry.
“The Environmental Working Group did a study where they looked at products marketed to Black women and looked for ingredients with the highest hazardous chemicals,” Treviño said. “Propylparaben, butylparaben and methylparaben popped up as being on the top of the list.”
Treviño and colleagues compared the effects of propylparaben, butylparaben and methylparaben exposure on the MCF-7 cell line, predominantly found in women with European ancestry, and the HCC1500 cell line, predominantly found in women of West African ancestry.
The viability of the HCC1500 cancer cell line was significantly greater when exposed to butylparabens, whereas no effect was observed in the MCF-7 cell line. Methylparaben and propylparaben did not have a significant effect on cell viability.
Exposure to butylparaben and propylparaben increased the expression of estrogen-regulated genes in both the MCF-7 and HCC1550 cell lines, with a more robust increase observed in HCC1550. Treatment with the estrogen receptor antagonist ICI 182,780 reduced the increase in gene expression in both cell lines. However, co-treatment with ICI 182,780 did not affect the increased viability of butylparabens in HCC1500 cells.
The study was conducted as part of the Bench to Community Initiative, a project in which scientists and community members are coming up with ways to reduce exposure to parabens and other harmful chemicals in personal care products. Treviño said this is crucial for Black women, in particular, as incidence rates of breast cancer are higher in Black women younger than 45 years compared with white women, and the breast cancer death rate in Black women is about 40% higher than white women.
“Part of the Bench to Community Initiative is to educate women, to let them know that a lot of the products have a lot of these harmful chemicals, including parabens and many others,” Treviño said. “It’s making sure people feel empowered and have the education to make those decisions and decide if they want to switch out their products.”
Treviño said the initiative is working with Black-owned businesses to maintain a database of chemical-free products and giving women a resource when choosing which personal care products to use.