Pregnane X Receptor Expression in Human Pancreatic Adenocarcinoma: Associations With Clinicopathologic Parameters, Tumor Proliferative Capacity, Patients' Survival, and Retinoid X Receptor Expression.
OBJECTIVE
Pregnane X receptor (PXR) has been involved in human malignancy, either by directly affecting carcinogenesis or by inducing drug-drug interactions and chemotherapy resistance. The present study aimed to assess the clinical significance of PXR in pancreatic adenocarcinoma.


METHODS
Pregnane X receptor and its heterodimers' PXR/retinoid X receptor α (RXR-α), RXR-β, and RXR-γ expression were assessed immunohistochemically on tumoral samples from 55 pancreatic adenocarcinoma patients and were associated with clinicopathologic parameters, tumor proliferative capacity, and patients' survival.


RESULTS
Enhanced PXR expression was noted in 24 (43.6%) of 55 pancreatic adenocarcinoma cases. Pancreatic adenocarcinoma patients presenting increased histological grade of tumor differentiation showed a significant increased incidence of elevated PXR expression (P = 0.023). Enhanced PXR/RXR-β expression was significantly associated with smaller tumor size and earlier clinical stage (P = 0.005 and P = 0.003, respectively). Elevated PXR/RXR-γ expression was significantly associated with smaller tumor size and earlier clinical stage (P = 0.012 and P = 0.014, respectively) and borderline with the absence of lymph node metastases (P = 0.056). In addition, pancreatic adenocarcinoma patients presenting enhanced PXR/RXR-γ expression showed marginally longer survival times compared with those with decreased expression (log-rank test, P = 0.053).


CONCLUSIONS
This study supported evidence that PXR and its copartners' overexpression may be associated with favorable clinicopathologic parameters and better outcome in pancreatic adenocarcinoma.
From the *First Department of Pathology, Medical School, National and Kapodistrian University of Athens, Athens; †Department of Food Science and Nutrition, School of the Environment, University of the Aegean, Myrina, Lemnos; ‡Department of Pathology, Tzaneio General Hospital, Piraeus; and §Second Department of Propedeutic Surgery, Medical School, University of Athens, Athens, Greece.
Ioannis
I
Koutsounas
Constantinos
C
Giaginis
Paraskevi
P
Alexandrou
Adamantia
A
Zizi-Serbetzoglou
Efstratios
E
Patsouris
Gregorios
G
Kouraklis
Stamatios
S
Theocharis
D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016009:Chi-Square Distribution; D018450:Disease Progression; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000706:statistics & numerical data; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D010190:Pancreatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D000077297:Pregnane X Receptor; D016016:Proportional Hazards Models; D011987:Receptors, Steroid / Q000096:biosynthesis*; D047490:Retinoid X Receptor alpha / Q000096:biosynthesis; D049230:Retinoid X Receptor beta / Q000096:biosynthesis; D047491:Retinoid X Receptor gamma / Q000096:biosynthesis; D047488:Retinoid X Receptors / Q000096:biosynthesis*
D000077297:Pregnane X Receptor; D011987:Receptors, Steroid; D047490:Retinoid X Receptor alpha; D049230:Retinoid X Receptor beta; D047491:Retinoid X Receptor gamma; D047488:Retinoid X Receptors