Nuclear Protein 1 Expression Is Associated with PPARG in Bladder Transitional Cell Carcinoma.

Background: The Nuclear protein 1 gene was first discovered in acute pancreatitis and functions as an oncogene in cancer progression and drug resistance. However, the role of Nuclear protein 1 in bladder transitional cell carcinoma (BTCC) is still unclear.

Methods: The Cancer Genome Atlas database and immunohistochemical analysis were adopted to evaluate Nuclear protein 1 expression in BTCC. We applied lentivirus-mediated small-interfering RNA to down-regulate the expression of Nuclear protein 1 in BTCC cell lines. We further performed an Affymetrix microarray and Gene Set Enrichment Analysis (GSEA) to assess the genes and signaling pathways related to Nuclear protein 1.

Results: We found that Nuclear protein 1 expression was up-regulated in BTCC and positively related to the degree of BTCC malignancy. Compared with Caucasian patients with BTCC, Nuclear protein 1 expression was attenuated in Asian patients. The Affymetrix microarray showed that lipopolysaccharide was the upstream regulatory factor of Nuclear protein 1 in BTCC. The GSEA indicated that Nuclear protein 1 expression was associated with signaling pathways in cancer, peroxisome proliferator-activated receptor (PPAR) pathways, and RNA degradation. The expression of Nuclear protein 1 was negatively correlated with PPARG (R = -0.290, P < 0.001), but not with PPARA (R = 0.047, P = 0.344) and PPARD (R = -0.055, P = 0.260).

Conclusions: The study findings indicate that Nuclear protein 1 is positively associated with the malignancy degree of BTCC and that Nuclear protein 1 expression is negatively correlated with PPARG.