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Nonn, L.

Publications and source records attributed to Nonn, L..

2 recordsLinked to original sources

Vitamin D Sufficiency Enhances Differentiation of Patient-Derived Prostate Epithelial Organoids

Vitamin D is an essential steroid hormone that regulates systemic calcium homeostasis and cell fate decisions, including differentiation in many cell types. The prostate gland is hormonally regulated, requiring steroids for proliferation and terminal differentiation of secretory luminal cells. Vitamin D deficiency is associated with higher risk of lethal prostate cancer with an aggressive dedifferentiated pathology, linking vitamin D sufficiency to epithelial differentiation homeostasis. To determine regulation of prostate epithelial differentiation by vitamin D status, patient-derived benign prostate epithelial organoids were maintained in vitamin D deficient (vehicle) or sufficient (10 nM 1,25-dihydroxyvitamin D) conditions and assessed by phenotype and single cell RNA sequencing. Mechanistic validation demonstrated that vitamin D sufficiency promoted organoid growth and accelerated differentiation of lineage-committed cells by inhibiting canonical Wnt activity and Wnt family member DKK3. Wnt dysregulation is a known contributor to aggressive prostate cancer, thus these findings further link vitamin D deficiency to lethal disease.

cell biology

Cell-type specific expression of oncogenic and tumor suppressive microRNAs in the human prostate and prostate cancer

MiR-1 and miR-143 are frequently reduced in human prostate cancer (PCa), while miR-141 and miR-21 are frequently elevated. Consequently, these miRNAs have been studied as cell-autonomous tumor suppressors and oncogenes. However, the cell-type specificity of these miRNAs is not well defined in prostate tissue. Through two different microdissection techniques, and droplet digital RT-PCR, we quantified these miRNAs in the stroma and epithelium of radical prostatectomy specimens. In contrast to their purported roles as cell-autonomous tumor suppressors, we found miR-1 and miR-143 expression to be predominantly stromal. Conversely, miR-141 was predominantly epithelial. MiR-21 was detected in both stroma and epithelium. Strikingly, the levels of miR-1 and miR-143 were significantly reduced in tumor-associated stroma, but not tumor epithelium. Gene expression analyses in human cell lines, tissues, and prostate-derived stromal cultures support the cell-type selective expression of miR-1, miR-141, and miR-143. Analyses of the PCa Genome Atlas (TCGA-PRAD) showed a strong positive correlation between stromal markers and miR-1 and miR-143, and a strong negative correlation between stromal markers and miR-141. In these tumors, loss of miR-1 and gain of miR-21 was highly associated with biochemical recurrence. These data shed new light on stromal and epithelial miRNA expression in the PCa tumor microenvironment.

cancer biology