Transcriptome analysis of pancreatic cancer patients with low and high metabolic tumor volume (MTV)

Transcriptome wide-comparison between MTV-low and -high groups was performed with three types: 1) cancer to normal site ratio, cancer site, and normal site. Among three types of comparison, the cancer-to-normal site ratio was the most informative. 211 genes were generally upregulated, and 166 genes were downregulated in the MTV-high group compared to the MTV-low group. Of 211 upregulated gens, 44 showed more than a 2-fold difference and statistical significance. On the other hand, of 166 downregulated genes, 56 showed more than a 2-fold difference and statistical significance. In functional annotation analysis, the GO terms of the upregulated genes were enriched to Wnt signaling (GO: 0035567, 0060070, 0060071), sister chromatid cohesion (GO: 0007062), and cell division (GO: 0000278, 0051301) trends (Figure 1E-a), whereas those of the downregulated genes were enriched to rRNA processing (GO: 0006364), translation (GO: 0006412, 0006413), nuclear-transcribed mRNA catabolic process (GO: 0000184) trends (Figure 1E-b). 28 upregulated genes belonged to Wnt signaling or Cell division, while 22 downregulated genes belonged to rRNA processing. Pancreatic cancer patients were classified into low MTV and high MTV groups by 18F-FDG PET/CT scan, and their post-resected tissues were used for total RNA-Seq.