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. 2016 Dec 27;8(12):19323–19341. doi: 10.18632/oncotarget.14252

Figure 7. Surface-bound Hsp90 co-segregates with a subset of PSA(lo)-expressing cells.

Figure 7

A. Androgen receptor (AR) responsive LNCaP and Myc-CaP prostate cancer cells were transiently transduced with lentiviral particles encoding PSA-GFP and GFP expression was assessed by flow cytometry. Approximately 70-80% of LNCaP are GFP+, while approximately 40% of MycCaP demonstrate similar positivity. PSA-Con refers to nontransduced control cells, while PSA-GFP refers to non-sorted bulk cells. B. Quantitative PCR analysis was performed on the indicated cell populations to determine the relative DNA expression of GFP, indicative of transduction efficiency. The populations are identified as follows: untransduced (PSA-con), transduced unsorted (PSA-GFP), and flow sorted PSA-GFP positive and negative (PSA-GFP(Hi)) and PSA-GFP(Lo)). C. Representative flow cytometry scatter plots demonstrating the relation between surface-bound Hsp90-alpha and PSA-GFP expression in LNCaP and MycCaP cells. D. Tabular depiction of replicate flow cytometry analyses for surface-bound Hsp90 in LNCaP and Myc-CaP cells. E. Model depicting the role of eHsp90 in supporting stem-like cellular heterogeneity. Collectively, our data support a model whereby secreted Hsp90 increases stem-like properties in prostate tumor cells. This was demonstrated by increased prostasphere growth, and expansion of both the side population (indicative of dye efflux and drug transporter activity) and ALDH activity. As indicated, the effectors EZH2 and Snail appear to differently impact seveal of these metrics. In tandem, tumor cells with elevated surface Hsp90 appear to correlate with lower levels of PSA-regulated GFP, indicating a potential inverse correlation between surface Hsp90 and androgen receptor (AR) regulation.