Abstract 4138: Evaluation of breast triple-negative 4T1-derived tumor metastatic development in gender-different mouse

Abstract

Abstract Background and Objective: Breast cancer in men is a rare and less-studied case, with therapeutic strategies predominantly relying on clinical treatment protocols established for women. To support the clinical treatment concept, Dr. Martin-Martinez's lab observed no differences in the time of orthotopic breast mammary fat pad tumor development, necrosis, or color change of tumor tissue between male and female mice. However, the clinical treatment readout, especially tumor metastasis, is different in men and women, and current models for breast cancer are inadequate due to the absence of metastases. It is necessary to evaluate the development of breast cancer 4T1-derived tumor metastasis in male and female mice. Method and Result: 4T1-Luc breast cancer cells were implanted in male and female Balb/c mice via various routes, including inguinal fat pad injection, tail vein injection, caudal artery injection, portal vein injection, and Intratibial Injection. Illuminance images showed no significant differences in tumor metastatic development between genders for inguinal fat pad, tail vein, and intratibial injections. However, following caudal artery injection, early-stage metastasis differed; male mice developed femoral head metastasis, while female mice developed lung metastasis. In the late stage, male mice displayed lung and femoral bone metastasis, while female mice primarily showed lung metastasis with barely bone metastasis. Conclusion: While both male and female mice showed similar primary breast tumor development, mouse gender affected tumor metastasis differently, particularly when tumor cells went through the caudal artery. Male mice presented earlier femoral head metastasis and less lung metastasis than female mice. Based on this work, sex hormones would affect both hormone-related and nonhormone-related tumor metastasis. To elucidate whether this phenomenon is caused by estrogen or androgen or to test if a drug has any beneficial effects, HD Biosciences provides established tumor metastatic cell-delivering platforms and over 1000 cancer cell lines for target validation and drug efficacy study. Citation Format: Chunhong Shao, Melanie He, Luke Tsung-Huang Tsai. Evaluation of breast triple-negative 4T1-derived tumor metastatic development in gender-different mouse [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4138.