Raman microspectroscopy for probing the impact of a dietary antioxidant on human breast cancer cells

Abstract

Breast cancer is the second most common type of cancer worldwide and the most frequent among women, being the fifth cause of death from neoplastic disease. Since this is an oxidative-stress related neoplasia, it is largely preventable. A dietary isoflavone abundant in soybean -daidzein -was currently investigated as to its chemopreventive and/or chemotherapeutic properties towards the human MDA-MB-231 (metastatic, estrogen-unresponsive) and MCF-7 (estrogen-responsive) breast cancer cell lines. Biological assays for evaluation of antitumour and anti-invasive activities were combined with state-of-theart vibrational microspectroscopy techniques. At 50 and 100 µM concentrations and 48 h incubation time, daidzein was found to induce a marked decrease in cell viability (ca. 50%) for MDA-MB-231 and MCF-7 cells (respectively ca. 50% and 42%) and 40% inhibition of cell migration 48 h. MicroRaman analysis of fixed cells upon exposure to this isoflavone unveiled its metabolic impact on both cell lines. Multivariate data analysis (unsupervised PCA) led to a clear discrimination between control and DAID-exposed cells, with distinctive effects on their biochemical profile, particularly regarding DNA, lipids and protein components, in a cell-dependent way. This is the first reported study on the impact of dietary antioxidants on cancer cells by microRaman techniques. A IntroductionCancer is one of the major causes of morbidity and mortality worldwide, closely following cardiovascular disorders. Breast carcinoma, in particular, is an important public health problem since it is the second most lethal cancer among women worldwide: according to the World Health Organisation (WHO), it affects 28% of the women in Europe 1 , being the second most lethal cancer type in Portugal (16%). 2 Epidemiological evidence has demonstrated a clear difference in breast cancer incidence between eastern and western countries, asian women being the least affected, which can be closely related to dietary habits.Phytochemicals, secondary plant metabolites widespread in fruits, vegetables, cereals and beverages such as tea, coffee and wine, and very abundant in a mediterranean diet, are an abundant source of dietary antioxidants known to significantly decrease the harmful effect of oxidative species, thus being promising chemopreventive agents towards carcinogenesis. [3][4][5][6] Actually, several studies have established a direct relationship between the intake of polyphenols and the prevention of oxidative stress-induced diseases, namely neurodegenerative and cardiovascular disorders, and some types of cancer. 7,8 The isoflavone daidzein (DAID), in particular, is the second most abundant component of soybean (following genistein), a growingly consumed food product, which renders this isoflavone a very suitable target of study regarding its potential health beneficial effects. In addition, it exhibits structural and functional similarities to the endogenous hormone estrogen 9 (Fig. 1). Since some breast cancers are estrogen-dependent (ER + ), DAID may...

Applications of Raman spectroscopy in cancer diagnosis

“…Its effect varied between estrogen-dependent and estrogen-independent cells. In MDA-MB-231 cells, cellular protein content was affected, and in MCF-7 cells, DNA and lipids were affected compared to control cells [153].…”

Shedding light into the health‐beneficial properties of Corema album—A vibrational spectroscopy study

“…This can be accomplished by the use of Raman and Fourier‐transform infrared (FTIR) vibrational spectroscopy techniques that have been established as non‐invasive tools of excellence for the characterisation of biospecimens with high sensitivity and selectivity . Raman microspectroscopy, in particular, is a cutting‐edge technique that enables an accurate and non‐invasive profiling of biological samples of several types (e.g., plants, human cells, or tissues), virtually without interference from water, yielding unique chemical fingerprints . Actually, the high sensitivity and subcellular spatial resolution of microRaman allows us to detect the smallest chemical variations and conformational rearrangements even in heterogeneous biological models such as leaves, fruits, or seeds.…”

The Anticancer Effects of Flavonoids through miRNAs Modulations in Triple-Negative Breast Cancer

“…Myricetin-treated MDA-MB-231 cells showed a significant reduction of cell viability, migration, metastasis, invasion, and adhesion through repressing the protein expression of MMP-2/9 [219]. Similarly, studies reported that exposure of the MDA-MB-231 TNBC cell to epigallocatechin-3-gallate, abundantly found in consumed tea, strongly repressed cell proliferation and invasion, caused G0/G1 cell-cycle arrest, reduced activation of MMP-2/9, suppressed expression of Bcl-2/Bax, decreased expression of c-Met receptor and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kβ) proteins levels, reduced phosphorylation of Akt, and promoted cell death by apoptosis [220]. Furthermore, in vitro studies on breast cancer cases showed that a time-dependent exposure of cells to kaempferol induced G2/M arrest by repressing cyclin A, Cyclin B, and CDK1 as promoted apoptosis by p53 phosphorylation in MDA-MB-231 TNBC cell [221].…”