ABSTRACT
The mass spectrometry-based metabolomics method was used to systematically investigate the formation of celastrol metabolites,and the effect of celastrol on endogenous metabolites. The mice plasma,urine and feces samples were collected after oral administration of celastrol. Ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry( UPLC-QTOF-MS) was applied to analyze the exogenous metabolites of celastrol and its altered endogenous metabolites. Mass defect filtering was adopted to screen for the exogenous metabolites of celastrol. Multivariate statistical analysis was used to identify the endogenous metabolites affected by celastrol. Celastrol and its eight metabolites were detected in urine and feces of mice,and 5 metabolites of them were reported for the first time. The hydroxylated metabolites were observed in the metabolism of both human liver microsomes and mouse liver microsomes. Further recombinant enzyme experiments revealed CYP3 A4 was the major metabolic enzyme involved in the formation of hydroxylated metabolites. Urinary metabolomics revealed that celastrol can affect the excretion of intestinal bacteria-related endogenous metabolites,including hippuric acid,phenylacetylglycine,5-hydroxyindoleacetic acid,urocanic acid,cinnamoylglycine,phenylproplonylglycine and xanthurenic acid. These results are helpful to elucidate the metabolism and disposition of celastrol in vivo,and its mechanism of action.
Subject(s)
Animals , Humans , Mice , Chromatography, High Pressure Liquid , Mass Spectrometry , Metabolomics , Microsomes, Liver , Metabolism , Triterpenes , Metabolism , PharmacokineticsABSTRACT
<p><b>OBJECTIVE</b>To detect the expression of prostate cancer antigen-1 (PCA-1) in prostate cancer, and to analyze the effects of downregulation of PCA-1 expression on malignant biological behavior of prostate cancer LNCaP cells, and to explore their possible molecular mechanisms.</p><p><b>METHODS</b>PCA-1-siRNA and control siRNA were transfected into LNCaP cells with lipofectamine 2000. The cell cycle, proliferation and migration were determined by methyl thiazolyl tetrazolium (MTT) assay, flow cytometry and Transwell chambers, respectively. Western blotting was used to detect the expression of cyclin E, matrix metallopeptidase 9 (MMP-9) and p21. Immunohistochemistry was used to detect the expression of PCA-1 protein in 126 cases of prostate cancer and 88 cases of benign prostatic hyperplasia (BPH).</p><p><b>RESULTS</b>The positive rate of PCA-1 expression was 77.8% (98/126) in prostate cancer, and 10.2% (9/88) in BPH, and its expression was not significantly related to age, prostate specific antigen (PSA), Eastern Cooperative Oncology Group (ECOG) score (P > 0.05), and was associated with Gleason score, TNM staging and bone metastasis (P < 0.05). Downregulation of PCA-1 expression inhibited cell proliferation, arrested cell cycle at S phase and decreased cell migration of LNCaP cells. The downregulation of PCA-1 expression decreased the expression of Bcl-xl, cyclin E and MMP-9 proteins, but increased the expression of p21 proteins.</p><p><b>CONCLUSIONS</b>PCA-1 may play an important role in the development of prostate cancer. The downregulation of PCA-1 expression can lead to changes in the proliferation, cell cycle and migration of prostate cancer LNCaP cells, and these effects may be associated with the decrease of Bcl-xl, cyclin E and MMP-9 proteins and increase of p21 protein.</p>