Figure 1: Integrative analysis of gene expression and metabolic data sets identifies alterations in the hexosamine biosynthetic pathway in prostate cancer.

(a) Overview of integrative methodology. (b) Top pathways identified after integrative analysis using combined gene/metabolite-derived enrichment scores using our previously published¹⁰ data. Black dots indicate top six pathways identified as outliers and coloured arrows indicate the top five enriched pathways chosen for secondary analysis. (c) Network representation of pathways shown in b (solid coloured circles: enriched pathways after integrative analysis using combined gene/metabolite-derived enrichment scores; circumference is correlated to pathway connectivity). Association between interacting pathways and each of the enriched pathways (solid coloured circles) obtained after the integrative analysis is shown by coloured arrows, which also show the direction of interaction. Arrow thickness correlates with number of interacting components between two pathways. Enriched associated pathways (also termed interacting pathways) interacting with those listed in b, are shown in red rimmed circles. Thus, for example, amino sugar metabolism or HBP has eight interacting pathways, 5 of which are enriched (red rimmed circle). (d) Overview of the HBP. GNPNAT1 (red) is the most proximal consistently upregulated HBP enzyme in PCa. (e) GNPNAT1 product/substrate ratio was higher in PCa compared with matched benign-adjacent prostate tissues (n=15 pairs). P-value was calculated using Unpaired Student’s t-test. (f) Boxplots showing immunostaining of GNPNAT1 in primary PCa (n=67) versus benign adjacent (Ben, n=48), PCa versus lymph node mets (LN-Met, treatment naïve, n=28) and PCa versus CRPC mets (Met, n=50). P-value was calculated using Wilcoxon-Rank Sum test. (g) Representative photomicrograph of GNPNAT1 staining in 1: Ben (black arrows) with tumour nodules (red arrow); 2: PCa; 3, 4: LN-Met and 5, 6: Mets. Representative scale bar for sections 1, 3 and 4 is 100 μm (low power) and for sections 2, 5 and 6 is 25 μm (high power). In all cases, P-value of <0.05 was considered significant. For boxplots, the horizontal line represents median value, whereas Whiskers represent either <25 or >75 quartile ranges.