Evaluation of the Differences in the Expression of Biogenic Amine-Related mRNAs and Proteins in Endometrioid Endometrial Cancer

Biogenic amines, such as adrenaline, noradrenaline, histamine, dopamine, and serotonin are important neurotransmitters that also regulate cell viability. Their detection and analysis are helpful in the diagnosis of many diseases, including cancer. The aim of this study was to determine the expression profile of the biogenic amine-related genes and proteins in endometrioid endometrial cancer compared to the control group. The material consisted of endometrial tissue samples and whole blood collected from 30 endometrioid endometrial cancer patients and 30 cancer-free patients. The gene expression was determined by the mRNA microarrays and validated by qRT-PCR. Protein levels were determined in the serum by the enzyme-linked immunosorbent assay (ELISA). Overexpression of histamine H1–H3 receptors and early growth response 1 and silencing of calmodulin, the histamine H4 receptor, and the dopamine D5 receptor have been reported in endometrioid endometrial cancer. The obtained results indicate disturbances in the signaling activated by histamine and dopamine receptors, which could potentially contribute to the progression of endometrioid endometrial cancer.

Abstract P212: Peroxiredoxin-4 And Dopamine D5 Receptor Interact To Reduce Oxidative Stress And Inflammation In The Kidney

Peroxiredoxin-4 (PRDX4), an endoplasmic reticulum peroxiredoxin protein, plays a protective role against oxidative stress and inflammation by reducing hydrogen peroxide to water. The dopamine D5 receptor (D 5 R) is also important in protecting against oxidative stress, but the interaction between PRDX4 and D 5 R in regulating oxidative stress in the kidney is not known. In D 5 R-HEK 293 cells, fenoldopam (FEN, 25 nM/12 hr, n=4), a D1-likereceptor agonist, increased PRDX4 protein expression (1.92±0.12-fold over basal level, n=4), mainly in non-lipid rafts (LRs: 24.9±11.4%, non-LRs: 75.1±11.4%, baseline; LRs: 30.9±13.9%, non-LRs: 174.1±16.7%, FEN). FEN also increased the co-immunoprecipitation of D 5 R and PRDX4 and their colocalization, particularly in the endoplasmic reticulum. In human renal proximal tubule cells (hRPTCs), FEN (25 nM/12 hr, n=3) increased PRDX4 and D 5 R interaction in non-LRs, also. Si-RNA silencing of PRDX4 increased reactive oxygen species (ROS) production and impaired the inhibitory effect of FEN on ROS production (scrambled siRNA: 100.0±11.6% and 65.4±5.6% for Vehicle (Veh) and FEN, respectively; PRDX4 siRNA: 147.7±11.8% and 134.8±11.2% for Veh and FEN, respectively, n=4/group) detected by Amplex Red. In addition in both D 5 R-HEK 293 and hRPTCs, siRNA silencing of PRDX4 increased the production of interleukin-1β (26.88±3.8 and 46.40±4.2 pg/mL [n=3, D 5 R-HEK 293]; 15.87±1.2 and 37.9±1.4 pg/mL [n=3 in hRPTCs]), tumor necrosis factor (131.7±6.5 and 271.2±18.1 pg/mL [n=4, D 5 R-HEK 293]; 108.8±11.8 and 240.1±13.7 pg/mL [n=4 in hRPTCs]), and caspase-12 (15.21±3.8 and 40.78±4.3 ng/mL [n=4,n D 5 R-HEK 293]; 8.8±1.1 and 27.9±2.0 ng/mL [n=4, hRPTCs]). Furthermore, the protein expression of D 5 R was decreased in PRDX4 siRNA-treated D 5 R-HEK293 (~41.2%, n=3) and hRPTCs (~39.6%, n=3). PRDX4 protein was also reduced in the kidney homogenates from D 5 R -/- mice (WT: 1.00±0.18, n=5; D 5 R -/- : 0.686±0.14, n=4; P<0.05). Taken together, PRDX4 interacts with D 5 R to decrease oxidative stress and inflammation in the kidney.