Methylation pattern of caveolin-1 in prostate cancer as potential cfDNA biomarker

Abstract

High prevalence and mortality of prostate cancer (PCa) are well known global health issues. Novel biomarkers for better identifying patients with PCa are the subject of extensive research. Prostate specific antigen (PSA) shows low specificity in screening and diagnostics, leading to unnecessary biopsies and health costs. Eighty patients with PCa and benign prostate hyperplasia (BPH) were included in the study. We analyzed CAV1 gene expression and methylation in tissue. CAV1 cfDNA methylation from blood and seminal plasma was accessed as a potential PCa biomarker. Although methylation in blood plasma did not differ between PCa and BPH patients, methylation in seminal plasma showed better PCa biomarker performances than tPSA (AUC 0.63 vs. AUC 0.52). Discrimination of BPH and Gleason grade group 1 PCa patients from patients with higher Gleason grade groups revealed very good performance as well (AUC 0.72). CAV1 methylation is useful biomarker with potential for further seminal plasma cfDNA research, but its diagnostic accuracy should be improved, as well as general knowledge about cfDNA in seminal plasma.

Figure 1.

Overview of the experimental workflow. BPH: Benign prostatic hyperplasia; RP: Radical prostatectomy. Created with BioRender.

Figure 2.

Hematoxylin-eosin staining (A, C) and immunohistochemical staining for CAV1 (B, D) in benign prostatic hyperplasia (A, B) and prostate cancer (C, D) biopsy cores. 100x.

Figure 3.

Boxplots graphs showing the staining intensity score (A), staining proportion score (B), and staining score (C) of CAV1 expression across PCa, NTT, and BPH tissue (median, interquartile range, minimum, maximum). Wilcoxon matched-pairs signed-rank test, Mann–Whitney test. *P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001. BPH: Benign prostatic hyperplasia; PCa: Prostate cancer; NTT: non-tumorous tissue.

Figure 4.

Box plot presenting methylation percentage of each CpG site and average methylation in PCa, NTT, and BPH tissue. Box plot indicates median, interquartile range, minimum and maximum. Wilcoxon matched-pairs signed-rank test, Mann–Whitney test. PCa: Prostate cancer; NTT: Non-tumor tissue; BPH: Benign prostatic hyperplasia. *P ≤ 0.05, **P ≤ 0.01.

Figure 5.

Box plot presenting methylation percentage of each CpG site and average methylation in PCa, NTT, and BPH tissue. Box plot indicates median, interquartile range, minimum and maximum. Wilcoxon matched-pairs signed-rank test, Mann–Whitney test. PCa: Prostate cancer; NTT: Non-tumor tissue; BPH: Benign prostatic hyperplasia. *P ≤ 0.05, **P ≤ 0.01.

Figure 6.

Box plot presenting methylation percentage of each CpG site and average methylation in cfDNA from seminal plasma of patients with PCa and BPH. Box plot indicates median, interquartile range, minimum and maximum. Mann–Whitney U test. PCa: Prostate cancer; BPH: Benign prostatic hyperplasia. *P ≤ 0.05.

Figure 7.

Box plot presenting methylation percentage of cfDNA from seminal plasma at CpG1 site in patients with PCa and BPH. Box plot indicates median, interquartile range, minimum and maximum. Kruskal–Wallis test with post-hoc test Dunn's multiple comparison test. BPH: Benign prostatic hyperplasia; GGG: Gleason grade group; PCa: Prostate cancer. *P ≤ 0.05.

Figure 8.

ROC curve analyses of tPSA (A) and seminal CAV1 CpG1 methylation (B). ROC curve analyses were performed by comparing BPH patients with PCa patients and by comparing regrouped BPH and GGG1 patients with regrouped GGG2, GG3, and GGG5 patient. BPH: Benign prostatic hyperplasia; PCa: Prostate cancer; NTT: Non-tumorous tissue; GGG: Gleason grade group.