Enhanced characterization of breast cancer phenotypes using Raman micro-spectroscopy on stainless steel substrate. Issue 9 (17th February 2023)

• Record Type: Journal Article
• Authors: Thomas, Giju; Fitzgerald, Sean T.; Gautam, Rekha; Chen, Fuyao; Haugen, Ezekiel; Rasiah, Pratheepa Kumari; Adams, Wilson R.; Mahadevan-Jansen, Anita
• Is Part Of: Analytical methods. Volume 15:Issue 9(2023)
• Page Start: 1188
• Page End: 1205
• Publication Date: 2023-02-17
• Subjects: Chemistry, Analytic -- Periodicals; Analytical biochemistry -- Periodicals; Chemical laboratories -- Standards -- Periodicals; 543.1905
• DOI: 10.1039/d2ay01764d
• Languages: English
• ISSNs: 1759-9660

Abstract

Abstract : Stainless steel yields stronger Raman signal intensity than the traditional CaF2 substrate, demonstrating potential for improved spectral characterization which further reveals increased lipogenesis in HER2 overexpressing breast cancer cells. Abstract : Biochemical insights into varying breast cancer (BC) phenotypes can provide a fundamental understanding of BC pathogenesis, while identifying novel therapeutic targets. Raman spectroscopy (RS) can gauge these biochemical differences with high specificity. For routine RS, cells are traditionally seeded onto calcium fluoride (CaF2 ) substrates that are costly and fragile, limiting its widespread adoption. Stainless steel has been interrogated previously as a less expensive alternative to CaF2 substrates, while reporting increased Raman signal intensity than the latter. We sought to further investigate and compare the Raman signal quality measured from stainless steel versus CaF2 substrates by characterizing different BC phenotypes with altered human epidermal growth factor receptor 2 (HER2) expression. Raman spectra were obtained on stainless steel and CaF2 substrates for HER2 negative cells – MDA-MB-231, MDA-MB-468 and HER2 overexpressing cells – AU565, SKBr3. Upon analyzing signal-to-noise ratios (SNR), stainless steel provided a stronger Raman signal, improving SNR by 119% at 1450 cm −1 and 122% at 2925 cm −1 on average compared to the CaF2 substrate. Utilizing only 22% of laser power on sample relative to the CaF2 substrate, stainless steel still yielded improved spectral characterization over CaF2, achieving 96.0% versus 89.8% accuracy in BC phenotype discrimination and equivalent 100.0% accuracy in HER2 status classification. Spectral analysis further highlighted increased lipogenesis and altered metabolism in HER2 overexpressing cells, which was subsequently visualized with coherent anti-Stokes Raman scattering microscopy. Our findings demonstrate that stainless steel substrates deliver improved Raman signal and enhanced spectral characterization, underscoring its potential as a cost-effective alternative to CaF2 for non-invasively monitoring cellular biochemical dynamics in translational cancer research.