PUMA and NOXA Expression in Tumor-Associated Benign Prostatic Epithelial Cells Are Predictive of Prostate Cancer Biochemical Recurrence

Abstract

Background: Given that treatment decisions in prostate cancer (PC) are often based on risk, there remains a need to find clinically relevant prognostic biomarkers to stratify PC patients. We evaluated PUMA and NOXA expression in benign and tumor regions of the prostate using immunofluorescence techniques and determined their prognostic significance in PC. Methods: PUMA and NOXA expression levels were quantified on six tissue microarrays (TMAs) generated from radical prostatectomy samples (n = 285). TMAs were constructed using two cores of benign tissue and two cores of tumor tissue from each patient. Association between biomarker expression and biochemical recurrence (BCR) at 3 years was established using log-rank (LR) and multivariate Cox regression analyses. Results: Kaplan–Meier analysis showed a significant association between BCR and extreme levels (low or high) of PUMA expression in benign epithelial cells (LR = 8.831, p = 0.003). Further analysis revealed a significant association between high NOXA expression in benign epithelial cells and BCR (LR = 14.854, p < 0.001). The combination of extreme PUMA and high NOXA expression identified patients with the highest risk of BCR (LR = 16.778, p < 0.001) in Kaplan–Meier and in a multivariate Cox regression analyses (HR: 2.935 (1.645–5.236), p < 0.001). Conclusions: The combination of PUMA and NOXA protein expression in benign epithelial cells was predictive of recurrence following radical prostatectomy and was independent of PSA at diagnosis, Gleason score and pathologic stage.

High Keratin-7 Expression in Benign Peri-Tumoral Prostatic Glands Is Predictive of Bone Metastasis Onset and Prostate Cancer-Specific Mortality

“…The prognostic value of KRT7 expression was assessed in a cohort of radical prostatectomy specimens ( n = 285 patients) from well-balanced localized PC with clinical/ pathological characteristics detailed in Supplementary Table S1 [ 24 , 25 ]. The incidence of biochemical recurrence (BCR) at 5 years was 33% (94 patients), and 9.8% (28 patients) of the cohort had an onset of bone metastasis leading in 6.3% of cases (18 patients) to a prostate-cancer specific death.…”

“…In agreement, KRT7 staining in cells from the supra-basal layer was more pronounced in IHC (see below, arrows). The selection of different regions of interest was performed using mask algorithms and a multi-staining approach ( Figure 3 C–E) (a basal cell mask with p63/CKHMW and a luminal cell mask with KRT8/18 staining cocktail), as earlier reported [ 24 , 27 ]. KRT7 expression was mainly detected in basal and supra-basal cells from benign epithelial glands ( Figure 3 C–E).…”

“…This TF123 was composed of a total of six TMA blocks. For each patient, 2 adjacent benign duplicate 0.6 mm cores and 2 tumoral duplicate cores were available, as previously published [ 24 , 25 ]. The composition of the cohort is described in Supplementary Table S1 .…”

“…Data pre-processing was performed with quality control of the tissue cores as described previously [ 24 , 25 ]. To accurately compare all of the TMAs (6 separate blocks), an MFI normalization was performed to compensate for the observed differences related to slide scanning and imaging in the average fluorescence intensity between each slide arising from the 6 blocks.…”

Expression of ERBB Family Members as Predictive Markers of Prostate Cancer Progression and Mortality

“…In our laboratory, we identified several biomarkers associated with an increased risk of biochemical recurrence (BCR), such as p65 nuclear frequency [ 5 , 6 ], PTEN [ 7 ], CD73 [ 8 ], and PUMA-NOXA [ 9 ]. Additional biomarkers were also identified with an increased risk of development of bone metastases, e.g., nuclear p65 expression [ 10 ] and CCN3 [ 11 ], and the ability to predict PC specific mortality, such as nuclear p65 expression [ 10 ] and neutral endopeptidase CD10 [ 12 ].…”