Dormant castration-resistant prostate cancer organoids with hybrid basal-luminal cells and loss of sars-cov-2 host factors emerged under androgen deprivation

ABSTRACT

INTRODUCTION AND OBJECTIVE: Androgen deprivation therapy (ADT) can help maintain remission in advanced prostate cancer (PCa) patients with bone metastases, however, growth and metastatic spread often recur. To address the need for more predictive pre-clinical research platforms and to identify new targets and therapies for bone metastatic castration-resistant prostate cancer (CRPC). METHODS: We used patient-derived xenograft (PDX) tumors from bone metastatic prostate cancer patients to establish threedimensional (3D) organoids and investigated their response to ADT by either withholding di-hydro-testosterone (no DHT) or treating with enzalutamide. Cyst/spheroid quantitation, immunohistopathology, cell viability assay, qRT-PCR, RNA sequencing, gene set enrichment analysis (GSEA) and live cell cycle tracking using Fucci2BL were performed in PDXs PCSD1, PCSD13 and PCSD25 and compared to PCa Cell lines P, DU145 and LNCaP. RESULTS: ADT resulted in CRPC spheroids with CK5D CK8D cells, up-regulated stem-cell transcription factors, steroidogenic and neurogenic pathways and down-regulated AR-target genes, interferon, cell cycle, cell division and circadian pacemaker pathways. Enzalutamide-treated spheroids transitioned to G0 and AR protein was decreased but not AR mRNA. Moreover, ADT decreased both ACE2 and TMPRSS2, host cell viral entry factors for the severe acute respiratory syndrome (SARS) SARS-CoV-2. CONCLUSIONS: In organoids, or mini-tumors, established from prostate cancer bone metastasis PDXs, a novel type of dormant ADT-resistant cell with specific gene changes emerged which may be targeted in order to eradicate dormant metastases before they can progress. This study identified a new dormant CRPC basal-luminal hybrid prostate cancer cell and gene signature which may be therapeutically targeted to eradicate dormant CRPC bone metastases in order to prevent disease recurrence. ADT also reduced the cell factors required for SARS-CoV-2 or its variants to infect its host cells and thus may reduce COVID-19 disease severity. The PDX organoid models can be used to screen for therapies that target the dormant CRPC cells and that reduce ACE2 and TMPRSS2 expression to suppress viral load of SARS-CoV-2 and its variants.