Introduction

Oncotarget published "Benzophenone-3 promotion of mammary tumorigenesis is diet-dependent" which reported that Benzophenone-3 is a putative endocrine disrupting chemical and common ingredient in sunscreens. Although benzophenone-3 seemed protective on low-fat diet, spindle cell tumors arising in these mice showed increased proliferation and decreased apoptosis. This points to a need for further studies of benzophenone-3 in both animal models and humans as a potential breast cancer risk factor, as well as a more general need to evaluate endocrine disrupting chemicals in varying dietary contexts. Dr. Richard C. Schwartz and Dr. Sandra Z. Haslam, both from The Michigan State University said, "Ovarian hormones are strongly implicated in the etiology of breast cancer." Putative endocrine disrupting chemicals, particularly estrogenic chemicals, have emerged as suspects in environmental promotion of breast cancer. Environmental EDCs have the potential to act as agonists or antagonists in critical hormonally regulated processes, such as mammary gland development and mammary tumorigenesis - this warrants evaluation of their potential in promoting breast cancer. More recently, BP-3 was demonstrated to have pathological effects on coral. Although BP-3 has a very short half-life, its presence is widespread in human urine, in as much as 98% of the general U.S. population. A recent preliminary study found plasma concentrations greater than 0.5 ng/mL among a small human cohort using heavy topical applications of commercial sunscreens. The present study examined the interaction of BP-3 with HFD on mammary tumorigenesis in BALB/c mice, using the Trp53-null transplantation model. A level of BP-3 exposure was used that yielded levels in murine urine similar to that observed in humans subjected to heavy topical exposure of BP-3-containing commercial sunscreen. These authors found that BP-3 had complex effects that were dependent upon dietary regimen and tumor histopathology. The Schwartz/Haslam Research Team concluded in their Oncotarget Research Output that unlike several earlier studies that found rather minimal BP-3 activity in vivo in rodents with doses higher than those in the current study: 1500 mg/kg BW/d; 1000 mg/kg BW/d; 150 mg/kg BW/d, these authors tumorigenesis experiments showed significant effects at 70 mg/kg BW/d. This dosage elicits levels of BP-3 excretion in urine similar to that observed in humans with heavy topical application of BP-3-containing sunscreen. Furthermore, their initial experiments in wild type BALB/c mice found significant effects on mammary epithelial proliferation at only 7 mg/kg BW/d. These observations suggest caution in the use of BP-3-containing sunscreens. DOI - https://doi.org/10.18632/oncotarget.27831 Full text - https://www.oncotarget.com/article/27831/text/ Correspondence to - Richard C. Schwartz - schwart9@msu.edu and Sandra Z. Haslam - shaslam@msu.edu Keywords - oxybenzone, benzophenone-3, mammary tumorigenesis, dietary animal fat, breast cancer About Oncotarget Oncotarget is a peer-reviewed, open access biomedical journal covering research on all aspects of oncology. To learn more about Oncotarget, please visit https://www.oncotarget.com or connect with: SoundCloud - https://soundcloud.com/oncotarget Facebook - https://www.facebook.com/Oncotarget/ Twitter - https://twitter.com/oncotarget LinkedIn - https://www.linkedin.com/company/oncotarget Pinterest - https://www.pinterest.com/oncotarget/ Reddit - https://www.reddit.com/user/Oncotarget/ Oncotarget is published by Impact Journals, LLC please visit https://www.ImpactJournals.com or connect with @ImpactJrnls Media Contact MEDIA@IMPACTJOURNALS.COM 18009220957x105 Copyright © 2021 Impact Journals, LLC Impact Journals is a registered trademark of Impact Journals, LLC