Infrared microspectroscopy identifies biomolecular changes associated with chronic oxidative stress in mammary epithelium and stroma of breast tissues from healthy young women

Abstract

Studies of the decades-long latent stages of breast carcinogenesis have been limited to when hyperplastic lesions are already present. Investigations of earlier stages of breast cancer (BC) latency have been stymied by the lack of fiducial biomarkers needed to identify where in histologically normal tissues progression toward a BC might be taking place. Recent evidence suggests that a marker of chronic oxidative stress (OxS), protein adducts of 4-hydroxy-2-nonenal (4HNE), can meet this need. Specifically: (1) 4HNE immunopositive (4HNE+) mammary epithelial (ME) cells were found to be prevalent in normal (reduction mammoplasty) tissues of most women (including many teenagers) studied, representative of those living in the United States' high risk-posing environment and: (2) marked (> 1.5-fold) differences were identified between tissues of healthy young women with many vs. few 4HNE+ ME cells in the relative levels of transcripts for 42 of the 84 OxS-associated genes represented in SABioscience Oxidative-Stress/Oxidative-Defense PCR array. Herein we used synchrotron radiation-based Fourier-transform infrared (SR-FTIR) microspectroscopy to identify molecular changes associated with 4HNE adducts in basal and luminal ME cells in terminal ductal units (TDLU), which are the cells of origin of BC, and associated intralobular and interlobular stroma, known contributors to carcinogenesis. Multivariate analysis-derived wavenumbers differentiated 4HNE+ and 4HNE- cells in each of the anatomical compartments. Specifically, principal component and linear discriminant analyses of mid-infrared spectra obtained from these cells revealed unambiguous, statistically highly significant differences in the "biochemical fingerprint" of 4HNE+ vs. 4HNE- luminal and basal ME cells, as well as between associated intralobular and interlobular stroma. These findings demonstrate further SR-FTIR microspectroscopy's ability to identify molecular changes associated with altered physiological and/or pathophysiological states, in this case with a state of chronic OxS that provides a pro-carcinogenic microenvironment.

Marginal zinc intake reduces the protective effect of lactation on mammary gland carcinogenesis in a DMBA-induced tumor model in mice

“…Reactive oxygen species damage DNA through oxidation, methylation, de-amination and de-purination and disrupt the system of oxidative damage repair through oxidation of their catalytic moieties. In fact, a recent report from Patel and colleagues (35) found that breast tissue enriched in oxidative stress had substantial differences in their 'biochemical fingerprint' suggesting profound changes in cell metabolism prior to (or perhaps during) carcinogenesis. Notably, while DMBA increased oxidative stress in the mammary glands of Zn adequate mice, the mice were able to activate the antioxidant prdx1 suggesting that these mice were able to manage the oxidative stress caused by the carcinogen.…”

Insights into Biochemical Alteration in Cancer-Associated Fibroblasts by using Novel Correlative Spectroscopy

“…Hydroxyl radicals can react with many biomolecules such as lipids, proteins, and nucleic acids, in almost all cellular organelles . These current data suggest that future studies can use FTIR spectroscopy to direct relative changes in 4HNE production, during chronic oxidative stress, to test the hypothesis that chronic oxidative stress might contribute to a higher incidence of breast cancer metastasis . Previous studies have reported alterations in intensity of the band centered at 1440 cm −1 , where it was observed that higher absorbance of this band correlated with a more severe tumor grade .…”

“…[28] These current data suggest that future studies can use FTIR spectroscopy to direct relative changes in 4HNE production, during chronic oxidative stress, to test the hypothesis that chronico xidative stress might contribute to ah igher incidence of breast cancer metastasis. [27] Previous studies have reported alterations in intensity of the band centereda t1 440 cm À1 ,w here it was observed that higher absorbance of this band correlated with am ore severe tumor grade. [29] It was postulated in the previouss tudy that these changes might be related to changes in the extracellular matrix.…”

“…We propose that the appearance of the peak at 1721 cm À1 in SFs might arise from aldehydec arbonyl stretching of 4-hydroxynonenal (4-HNE), ab iomarker of lipid peroxidation. [27] The FTIR spectrum of 4-HNE has been shown to also display ac haracteristic peak at 1440 cm À1 (Figure 1B), assigned to CÀHb ending in CH 3 groups of 4-HNE.A ss hown in Table 1, an increased area under the curve in the second-derivative spectrum wasa lso observed at 1440 cm À1 in SFs, providing additional support for 4-HNE production during fibroblast stimulation.…”

“…Additionally, a concomitant decrease in the ester carbonyl peak intensity (1735 cm −1 ), was observed (Figure D and Table ), suggesting a possible chemical relationship. We propose that the appearance of the peak at 1721 cm −1 in SFs might arise from aldehyde carbonyl stretching of 4‐hydroxynonenal (4‐HNE), a biomarker of lipid peroxidation . The FTIR spectrum of 4‐HNE has been shown to also display a characteristic peak at 1440 cm −1 (Figure B), assigned to C−H bending in CH 3 groups of 4‐HNE.…”