CHANGES IN PROLACTIN RECEPTOR LOCATION IN PROSTATE TUMORS

LÓPEZ FONTANA GASTÓN; REY LARA; SANTIANO, FLAVIA E.; LÓPEZ FONTANA RODRIGO; LÓPEZ LAUR JD; ZYLA, LEILA E.; VALDEMOROS, PAULA; GUERRERO-GIMÉNEZ MARTÍN; FERNÁNDEZ MUÑOZ, JUAN MANUEL ; GÓMEZ, SILVINA; BRUNA, FLAVIA A.; GUGLIELMI, JUAN MANUEL; CARÓN, RUBÉN W.

ARCHIVOS ESPANOLES DE UROLOGIA.

Iniestares, S.A.

Año: 2021

0004-0614

IntroductionProlactin (PRL) binds its receptor (PRLR) and stimulates cell proliferation,differentiation and survival in prostate cancer (PCa) cell lines via STAT5a, MAPK andAKT. Objective: To evaluate the expression of PRL and PRLR in normal and tumorprostate tissues with different Gleason patterns.MethodsSamples of normal, benign prostatic hyperplasia and PCa with different Gleasonpatterns were selected from radical prostatectomy. The intensity, location andpercentage of stained cells for PRL and PRLR were evaluated byImmunohistochemistry. Co-localization was observed by confocal microscopy.ResultsPRL was expressed diffusely and with a mild intensity in the cytoplasm of normal andtumor prostate luminal cells. Its expression only augmented in the Gleason 3 pattern (p0.0001). The immunostaining intensity and the percentage of positive cells for PRLRdid not vary between normal and tumor tissues. However, the location of the PRLRwas modified by the tumorigenic process. In non-tumor tissues, PRLR expression wasmostly in plasma membrane in the apical zone of epithelial cells. In tumor tissues, itwas expressed in intracellular vesicles. The co-localization of PRL and PRLR wasdemonstrated in normal and tumor tissues suggesting that PRL could be acting in anautocrine and paracrine manner.ConclusionPRL and its receptor were present in the cytoplasm of the epithelial cells of the normaland tumor prostate gland. In tumor tissues, the change in the location and appearanceof cryptic PRLRs that store PRL may keep active the different signaling pathwaysrelated to cell proliferation and survival.