Human and murine prostate basal/stem cells are not direct targets of prolactin

Cell Plasticity in a Mouse Model of Benign Prostate Hyperplasia Drives Amplification of Androgen-Independent Epithelial Cell Populations Sensitive to Antioxidant Therapy

Benign prostate hyperplasia (BPH) is caused by the nonmalignant enlargement of the transition zone of the prostate gland, leading to lower urinary tract symptoms. Although current medical treatments are unsatisfactory in many patients, the limited understanding of the mechanisms driving disease progression prevents the development of alternative therapeutic strategies. The probasin-prolactin (Pb-PRL) transgenic mouse recapitulates many histopathological features of human BPH. Herein, these alterations parallel urodynamic disturbance reminiscent of lower urinary tract symptoms. Single-cell RNA-sequencing analysis of Pb-PRL mouse prostates revealed that their epithelium mainly includes low-androgen signaling cell populations analogous to Club/Hillock cells enriched in the aged human prostate. These intermediate cells are predicted to result from the reprogramming of androgen-dependent luminal cells. Pb-PRL mouse prostates exhibited increased vulnerability to oxidative stress due to reduction of antioxidant enzyme expression. One-month treatment of Pb-PRL mice with anethole trithione (ATT), a specific inhibitor of mitochondrial ROS production, reduced prostate weight and voiding frequency. In human BPH-1 epithelial cells, ATT decreased mitochondrial metabolism, cell proliferation, and stemness features. ATT prevented the growth of organoids generated by sorted Pb-PRL basal and LSCmed cells, the two major BPH-associated, androgen-independent epithelial cell compartments. Taken together, these results support cell plasticity as a driver of BPH progression and therapeutic resistance to androgen signaling inhibition, and identify antioxidant therapy as a promising treatment of BPH.

Gold nanoparticles regulate the antitumor secretome and have potent cytotoxic effects against prostate cancer cells

The specific cytotoxic effects of nanoparticles on tumor cells may be used in future antitumor clinical applications. Gold nanoparticles (AuNPs) have been reported to produce potent cytotoxic effects; however, the precise mechanism is unclear. In this study, AuNPs were synthesized; the average size of the particles was 62.2 ± 6 nm with smooth surface and multiple shapes, which were determined using transmission electron microscopy and field emission scanning electron microscopy. The selected area electron diffraction patterns suggested that the synthesized AuNPs were crystalline. The X-ray photoelectron spectroscopy (XPS) spectrum of the synthesized AuNPs has presented an intense peak at 100 eV, signifying the entire composition of Au in the developed AuNPs. This synthesized AuNPs showed the most potent efficacy in prostate cancer cells, regardless of whether or not they were androgen dependent. Secretome determinations using two-dimensional difference in-gel electrophoresis (2D-DIGE), followed by enzyme-linked immunosorbent assay and quantitative reverse transcriptase-polymerase chain reaction validations, have identified a series of secretory proteins that were dysregulated by AuNP treatment in prostate cancer cells, many of which are highly involved in cytokine-chemokine functions, including CXCL3, interleukin-10, CCL2, and matrix metalloproteinase 9 (MMP9). Further research on molecular mechanism has indicated that AuNPs can trigger the secretion of anticancer factors and myeloid cell-polarizing factors from tumor cells through MMP9 inhibition. These results have clearly signified the cytotoxic potential of AuNPs for treating prostate cancer and may provide a novel direction for prostate cancer therapy in the future.

Influence of postnatal prolactin modulation on the development and maturation of ventral prostate in young rats

Besides androgenic dependence, other hormones also influence the prostate biology. Prolactin has been described as an important hormone associated with maintenance of prostatic morphophysiology; however, there is a lack of information on the involvement of prolactin during prostate development and growth. This study aimed to evaluate whether perinatal prolactin modulation interferes with rat ventral prostate (VP) development and maturation. Therefore, prolactin or bromocriptine (an inhibitor of prolactin release from the pituitary) were administered to Sprague Dawley rats from postnatal Day (PND) 12 to PND 21 or 35. Animals were then killed and serum hormonal quantification, VP morphological-stereological and immunohistochemical analyses and western blotting reactions were employed. Our results demonstrate that prolactin blockage increased serum testosterone on PND 21, which reflected an increase in anogenital distance. Although prolactin modulation did not interfere with VP weight, it modified VP morphology by dilating the acinar lumen and reducing epithelial cell height. Prolactin activated the signal transducer and activator of transcription (STAT) downstream pathway, increased androgen receptor expression and epithelial proliferation. In addition, prolactin and bromocriptine also increased expression of cytokeratin 18, a marker of luminal-differentiated cells. In conclusion, the VP responds to prolactin modulation through a mechanism of increasing the epithelial proliferative response and dynamics of cell differentiation, especially in animals treated for a more prolonged period.