Identification of candidate genes by metabolome assay and confirmation of EGLN2 and EGLN3 expression levels and knock-down by siRNA system. (A) Levels of three serum metabolites, glucose-6-phosphate (G6P), malonate, and hydroxyproline, were significantly higher in patients with distant metastases compared to those without distant metastases. Ten genes shown in figure were identified, after some genes involved in the above three serum metabolites were searched by Human Metabolome Database. Among these, levels of EGLN2 and EGLN3 genes were significantly upregulated compared with the control. EGLN2 and EGLN3 levels were relatively lower in the pancreatic cancer cell lines compared to MCF10A in (B). And EGLN2 and EGLN3 mRNA levels were higher in hypoxic conditions compared to normoxia in (B). The siRNAs decreased EGLN2 or EGLN3 expression in pancreatic cancer cells, especially under hypoxic conditions in (C).