Correlation analysis of urine metabolites and clinical staging in patients with ovarian cancer

Abstract

This study is to investigate the correlation between urine metabolites and clinical staging in patients with ovarian cancer. The urina sanguinis from 56 cases of primary epithelial ovarian cancer patients and 15 healthy volunteers was collected and the urine metabolites were extracted. Ultra high performance liquid chromatography/time-of-flight mass spectrometry (UPLC-Q-TOF-MS) analysis was performed. Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were used to analyze the mass spectrometry data. Database retrieval and comparison of the screened metabolites were performed and one-way ANOVA and least significant difference (LSD) t test were carried out. PCA analysis of UPLC-Q-TOF-MS results showed that the score plots of samples from healthy people and patients with ovarian cancer at different clinical stages were separated. Further PLS-DA analysis significantly improved the classification results. The R(2)X was 0.757, the R(2)Y was 0.977 and the Q(2)Y was 0.87, indicating that the model stability and predictability were good. Eight metabolites, including N-acetylneuraminic acid-9-phosphate, 5'-methioadenosine, uric acid-3-nucleoside, pseudouridine, L-valine, succinic acid, L-proline and β-nicotinamide mononucleotide were identified. The contents of these metabolites increased with the development of the disease. There was correlation between urine metabolites and clinical staging in patients with ovarian cancer.

Keywords: Ovarian cancer; metabonomics; staging; ultra high performance liquid chromatography/time-of-flight mass spectrometry; urine.

Figure 1

Representative total ion chromatography of urine UPLC-Q-TOF-MS analysis of patients with ovarian cancer.

Figure 2

PCA score plot of urine metabolism in healthy people and patients with ovarian cancer. Each point in the graph represents a sample. ○: healthy people, ▲: stage I ovarian cancer patients, ■: stage II ovarian cancer patients, □: stage III ovarian cancer patients, ●: stage IV ovarian cancer patients.

Figure 3

Partial least squares discriminant analysis score plot of urine metabolism in normal people and patients with ovarian cancer. ○: healthy people, ▲: stage I ovarian cancer patients, ■: stage II ovarian cancer patients, □: stage III ovarian cancer patients, ●: stage IV ovarian cancer patients.

Figure 4

Relative contents of the different urine metabolites in ovarian cancer patients. A. N-acetylneuraminic acid-9-phosphate; B. 5’-methioadenosine; C. Uric acid-3-nucleoside; D. Pseudouridine; E. L-valine; F. Succinic acid; G. L-proline; H. β-nicotinamide mononucleotide. aP < 0.05 vs control, bP < 0.01 vs control; cP < 0.05 vs stage I, dP < 0.01 vs stage I; eP < 0.01 vs stage II; fP < 0.05 vs stage III; gP < 0.01 vs stage III. C: The control group; I-IV: different stages of ovarian cancer group. The ordinate is the relative content of metabolites and the abscissa is grouping.