Single cell sequencing reveals luminal epithelial plasticity with fibroblast activation upon SRD5A2 deletion in the prostate
Christina Sharkey, MLA, Xingbo Long, MD, Zongwei Wang, PhD, Aria F. Olumi, MD.
Beth Israel Deaconess Medical Center, Boston, MA, USA.
Background: Steroid 5α reductase 2 (SRD5A2) is the predominant enzyme responsible for prostatic development and growth. SRD5A2 inhibitors are the only class of benign prostate hyperplasia-related medications that reduce prostate size. However, patients respond variably to 5ARI therapies. Due to epigenetic modifications, we have previously demonstrated that 30% of adult human prostatic tissues do not express the SRD5A2 gene and protein. The goal of this study is to use single cell RNA sequencing (scRNA seq) to characterize the prostate cellular and transcriptomic changes when SRD5A2 is absent. Material and Methods: Homozygous SRD5A2-/- mice and littermate heterozygous SRD5A2+/- control mice were generated. The intact prostate tissues were collected from 8-16 weeks old mice and digested for single cells. ScRNA seq with 10x genomics platform, followed by unsupervised clustering, was utilized to generate cell clusters based on differentially expressed (DE) gene profiles. A complete transcriptomic profile was obtained to identify cellular subsets and functional differentiation. Results: ScRNA seq resulted in transcriptome data for clustering of 23,000 single cells, which were further annotated to 18 subpopulations demonstrating the heterogeneity within prostate. The SRD5A2 gene was identified to exclusively express in fibroblasts and myofibroblasts. Deletion of SRD5A2 induced a significant decrease of epithelial luminal cells (53.2% vs 31.8%), while there was a significant elevation of stromal (11.3% vs 18.0%) and immune cells (3% vs 6.6%). Further sub-clustering of luminal cells identified 3 unique subclusters with gene signature of lineage, estrogen and progenitor pathways. Luminal cells with lineage signature and progenitor signature diminished whereas luminal cells with estrogen signature stably survived after SRD5A2 knock down. Meanwhile, cell-cell communication analysis showed that fibroblasts have broad ligand/receptor interactions with other cell types. In particular, fibroblasts support the epithelial proliferation and immune cells recruitment of prostate through secretion of growth factors (EGF, FGF and IGF families) and cytokines (CXCL, CCL and HLA). More importantly, absence of SRD5A2 in fibroblasts exhibited significantly increased expression patterns of inflammatory, epithelial-mesenchymal transition and angiogenesis genes. Conclusion: Our data suggests that luminal cells with the signature of estrogen response gene, and fibroblasts that have the enhanced function may synergistically contribute to 5ARI treatment resistance. Understanding the mechanism(s) by which prostatic fibroblasts regulate development of epithelial luminal cells may pave the way to find new therapeutic targets to the management of BPH patients who lack of SRD5A2 expression and are potentially resistant to 5ARI.
Back to 2021 Abstracts