Abstract 4558: Using reduction mammoplasty tissues from healthy young women living in USA's high breast cancer (BC) risk posing environment to open up to study the “black box” of latent stages of breast carcinogenesis; a key to develop strategies for BC

Proceedings: AACR 106th Annual Meeting 2015; April 18-22, 2015; Philadelphia, PA Knowledge of latent stages of breast carcinogenesis is limited to when histological changes are already present due to a lack of; a) cytochemical marker(s) needed to identify loci in histologically normal breast tissues where procarcinogenic conditions exist and; b) microscopic systems needed to geno- and phenotype cells in such loci. In 2 recent publications we presented evidence that protein adducts of 4-hydroxy-2-nonenal (4HNE), markers of a procarcinogenic state of chronic oxidative stress (OxS), might provide the needed fiducial marker. Specifically, a) we documented the presence of 4HNE immunopositive (4HNE+) mammary epithelial (ME) cells in terminal ductal units (TDLUs) in breast tissues of healthy teenagers and young women and their association with altered expression of OxS-related mRNAs and; b) presented Fourier-transform infrared microspectroscopic evidence of differences in biomolecular profile of ME cells and associated intra- and interlobular stromal cells in 4HNE+ vs. 4HNE- TDLUs, i.e., of cells of origin of BCs and cells in their supportive stromal microenvironment. Here we present further evidence of molecular changes in breast tissues of young women (ages 17-30 y) associated with 4HNE adducts. A comparison of the transcriptome of breast tissues with many 4HNE+ vs. few 4HNE+ TDLUs (controls) by Illumina 24,000 gene platform and SABioscience 84 gene Cell Death PCR Array revealed reprogramming of many homeostatic mechanism in 4HNE+ TDLUs. Notably, a) DASL platform identified transcripts for 395 genes that differed (p = 2 fold between 4HNE+ vs. 4HNE- tissues. The findings support using 4HNE adducts to identify in histologically normal breast tissues loci harboring cells that might initiate a cancer. Our findings fit an evolutionary model of carcinogenesis and reflect adaptive responses to stressors that serve to preserve tissue integrity, e.g., by developing resistance to OxS and to apoptosis, responses however that over time can lead to the emergence of a cancer. Our recently acquired Toponome Imaging System (TIS) enables identifying such responses to chronic OxS implied by the presence of 4HNE adducts. TIS is the first high throughput fluorescence robotic microscopic system that can provide a map, a toponome, of up to 100 proteins at 40nm functional resolution in individual cells in a tissue section. In ongoing experiments we are using TIS and antibodies against up to 21 proteins to test the postulate that 4HNE+ TDLUs are enriched with cells with an apoptosis resistant phenotype, a postulate supported by our transcriptional data and predicted by the evolutionary model of carcinogenesis. Citation Format: Judith Weisz, Debra Shearer, Anna C. Salzberg. Using reduction mammoplasty tissues from healthy young women living in USA's high breast cancer (BC) risk posing environment to open up to study the “black box” of latent stages of breast carcinogenesis; a key to develop strategies for BC [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4558. doi:10.1158/1538-7445.AM2015-4558