ORIGINAL PAPER Segregation of human prostate tissues classified high-risk (UK) versus low-risk (India) for adenocarcinoma using Fourier-transform infrared or Raman microspectroscopy coupled with discriminant analysis Imran I. Patel & Júlio Trevisan & Paras B. Singh & Caroline M. Nicholson & R. K. Gopala Krishnan & Shyam S. Matanhelia & Francis L. Martin Received: 8 March 2011 /Revised: 17 May 2011 /Accepted: 18 May 2011 /Published online: 4 June 2011 # Springer-Verlag 2011 Abstract Vibrational spectroscopy techniques can be applied to identify a susceptibility-to-adenocarcinoma biochemical signature. A sevenfold difference in incidence of prostate adenocarcinoma (CaP) remains apparent amongst populations of low- (e.g. India) compared with high-risk (e.g. UK) regions, with migrant studies implicating environmental and/ or lifestyle/dietary causative factors. This study set out to determine the biospectroscopy-derived spectral differences between risk-associated cohorts to CaP. Benign prostate tissues were obtained using transurethral resection from high-risk (n =11, UK) and low-risk (n =14, India) cohorts. Samples were analysed using attenuated total reflection Fourier-transform infrared (FTIR) spectroscopy, FTIR micro- spectroscopy and Raman microspectroscopy. Spectra were subsequently processed within the biochemical cell region (1,800 -1 –500 cm –1 ) employing principal component analysis (PCA) and linear discriminant analysis (LDA) to determine whether wavenumber–absorbance/intensity relationships might reveal biochemical differences associated with region-specific susceptibility to CaP. PCA-LDA scores and corresponding cluster vector plots identified pivotal segre- gating biomarkers as 1,582 cm -1 (Amide I/II trough); 1,551 cm -1 (Amide II); 1,667 cm -1 (Amide I); 1,080 cm -1 (DNA/RNA); 1,541 cm -1 (Amide II); 1,468 cm -1 (protein); 1,232 cm -1 (DNA); 1,003 cm -1 (phenylalanine); 1,632 cm -1 [right-hand side (RHS) Amide I] for glandular epithelium (P <0.0001) and 1,663 cm -1 (Amide I); 1,624 cm -1 (RHS Amide I); 1,126 cm -1 (RNA); 1,761, 1,782, 1,497 cm -1 (RHS Amide II); 1,003 cm -1 (phenylalanine); and 1,624 cm -1 (RHS Amide I) for adjacent stroma (P < 0.0001). Primarily protein secondary structure variations were biomolecular markers responsible for cohort segrega- tion with DNA alterations exclusively located in the glandular epithelial layers. These biochemical differences may lend vital insights into the aetiology of CaP. Keywords Aetiology . Biomarkers . FTIR microspectroscopy . PCA-LDA . Prostate cancer . Raman Abbreviations ATR- FTIR Attenuated total reflection Fourier-transform infrared CaP Prostate adenocarcinoma CZ Central zone E 2 17β-Oestradiol FFPE Formalin-fixed paraffin embedded H&E Haematoxylin and eosin IR Infrared LDA Linear discriminant analysis LHS Left-hand shoulder Electronic supplementary material The online version of this article (doi:10.1007/s00216-011-5123-z) contains supplementary material, which is available to authorized users. I. I. Patel : J. Trevisan : P. B. Singh : F. L. Martin (*) Centre for Biophotonics, Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster LA1 4YQ, UK e-mail: f.martin@lancaster.ac.uk P. B. Singh : C. M. Nicholson : S. S. Matanhelia Lancashire Teaching Hospitals NHS Trust, Fulwood, Preston PR2 9HT, UK R. K. G. Krishnan Workhardt Hospital, Kolkata 700020, India Anal Bioanal Chem (2011) 401:969–982 DOI 10.1007/s00216-011-5123-z