Table 1.
Characteristics of patients and prostate tissue samples.
Figure 1.
The prostate sample harvesting method after radical prostatectomy.
(A) The two HES-stained sections adjacent to the tissue slice. (B) To localize the cancer and normal areas, micrographs of the two HES stained histological sections adjacent to the removed tissue slice were fused with a photograph of the frozen tissue slice. The regions of interest were marked and transferred to a transparency sheet to be used as a map for guiding sample extraction. (C) Cylindrical samples (3 mm diameter) for HR-MAS were excised from regions with normal tissue and cancer tissue with different Gleason grades. The Gleason grade and the percentages of benign glandular tissue, stroma and cancer tissue were verified by analyzing a 4 µm cryosection from each extracted sample. The figure is adapted from reference [36].
Figure 2.
Representative HR-MAS spectra and corresponding HES stained prostate tissue samples with different Gleason grades.
Visual inspection of the spectra show decreased levels of polyamines (predominately spermine) and citrate, and increased levels of GPC, PCho, and Cho with increasing tumor grade.
Figure 3.
Prostate cancer metabolic profiles are correlated to aggressiveness.
(A) PLS scores and (B) loadings of LV1 and LV2 from PLS regression correlating the metabolic profiles to GS with a correlation coefficient r = 0.71. The cancer samples are separated from the normal samples in the score plot, with the loadings showing metabolic alterations related to malignancy. Samples with GS 9 are almost completely separated from normal adjacent samples in the score plot, while some samples with a lower score overlap with the normal ones. The PLSDA model explains 48.2% of the x-variance and 53.7% of the y-variance (C) PLS scores and (D) the corresponding loading profile of LV1 from PLS regression of the cancer samples only, correlating the metabolic profiles to GS with a correlation coefficient r = 0.45. The resulting model explains 20.0% of the x-variance and 27.4% of the y-variance of the data. The loadings in (B) and (D) are colored according to their VIP score. S-ino; scyllo-inositol.
Table 2.
Metabolite concentrations (mmol/kg) in cancer and normal prostate tissue samples.
Table 3.
Metabolite concentrations (mmol/kg) and ratios in low grade (GS = 6) and high grade (GS≥7) prostate cancer samples and comparison between different GSs.