The expression of ASS mRNA and protein in pancreatic cancer cell lines and human tissues. A, The level of ASS mRNA in human pancreatic cancer cell lines MIA PaCa-2, PANC-1, BxPC-3, and SW1990, breast cancer (low ASS-deficient tumor ) cell lines MDA-MB-453, BT474, MDA-MB-231, and MCF-7, and hepatocellular carcinoma (high ASS-deficient tumor [37, 38]) cell lines HepG2 and MHCC97-H were examined by qRT-PCR assay. B, Cytoplasmic localization of ASS protein in MIA PaCa-2, PANC-1, SW1990, and BxPC-3 cells was verified by immunofluorescence assay. C, The expression level of ASS protein was evaluated by western blot assay in the pancreatic cancer cell lines. D, The expression of ASS protein in 14 pancreatic cancer tissues was detected by western blotting (H1 is a normal hepatic tissue obtained from a hepatorrhexis patient), yielding that the deficiency of ASS protein expression was up to 50% (7/14). E, Relative mRNA levels of ASS in 9 pancreatic cancer tissues were analyzed by RT-PCR (H1 as depicted Figure 1D), reporting similar ASS deficiency as protein level in examined specimens. F, The relative expression levels of the p65 subunit of NF-κB and caspase-3 proteins in 14 pancreatic cancer tissues were detected by western blotting. G, The expression of ASS or survivin was determined in pancreatic cancer tissue samples using immunohistochemistry (IHC). Images i and ii show ASS expression in a tissue sample obtained from a grade 3 pancreatic adenocarcinoma patient with chronic pancreatitis and without metastasis to the lymph nodes or other organs, while iii and iv show ASS expression in a tissue sample obtained from a grade 2 invasive adenocarcinoma characterized by lymphatic and liver metastases. Images in v and vi show survivin expression in a tissue sample from a grade 2 invasive adenocarcinoma with tumor extension and invasion into peripancreatic fat and multiple fibrous adhesions.