The role of chromodomain helicase DNA binding protein 1 (CHD1) in promoting an invasive prostate cancer phenotype.

Background: Prostate cancer (PCa) phenotypes vary from indolent to aggressive. Molecular subtyping may be useful in predicting aggressive cancers and directing therapy. One such subtype involving deletions of chromodomain helicase DNA binding protein 1 (), a tumor suppressor gene, are found in 10-26% of PCa tumors. In this study, we evaluate the functional cellular effects that follow deletion.

Methods: was knocked out (KO) in the non-tumorigenic, human papillomavirus 16 (HPV16)-immortalized prostate epithelial cell line, RWPE-1, using CRISPR/Cas9. assays such as T7 endonuclease assay, western blot, and sequencing were undertaken to characterize the KO clones. Morphologic and functional assays for cell adhesion and viability were performed. To study expression of extracellular matrix (ECM) and adhesion molecules, a real-time (RT) profiler assay was performed using RWPE-1 parental, non-target cells (NT2) and CHD1 KO cells.

Result: Compared to parental RWPE-1 and non-target cells (NT2), the KO cells had a smaller, rounder morphology and were less adherent under routine culture conditions. Compared to parental cells, KO cells showed a reduction in ECM and adhesion molecules as well as a greater proportion of viable suspension cells when cultured on standard tissue culture plates and on plates coated with laminin, fibronectin or collagen I. KO cells showed a decrease in the expression of secreted protein acidic and rich in cysteine (SPARC), matrix metalloproteinase 2 (MMP2), integrin subunit alpha 2 (ITGA2), integrin subunit alpha 5 (ITGA5), integrin subunit alpha 6 (ITGA6), fibronectin (FN1), laminin subunit beta-3 precursor (LAMB3), collagen, tenascin and vitronectin as compared to parental and NT2 cells.

Conclusion: These data suggest that in erythroblast transformation specific (ETS) fusion-negative, phosphatase and tensin homolog () wildtype PCa, deletion of alters cell-cell and cell-matrix adhesion dynamics, suggesting an important role for in the development and progression of PCa.