A New Promising Pathway in Aggressive Prostate Cancer: Treg/mir-let8c/lin28b.

Purpose: The progress of prostate cancer entails complex contemporaneous tumor developmental events in diverse stages that they are still yet to be clarified. miRNAs might accompany to balance between regulatory and cytotoxic T cells in tumors. Here, we investigated miRNAs and Regulatory T cell (Treg) marker FOXP3 expressions within prostate cancer spectrum.

Methods: Thirty-eight prostate cancer patients enrolled within two groups to the study as having Gleason Score ≤ 7 (Group-1) and ≥ 8 (Group-2) that compared to 19 benign prostate hyperplasia controls. Twelve miRNAs expressions were analyzed by real time PCR from paraffin-embedded prostate tissue samples. Correlations between serum PSA levels, immunohistochemical staining of CD3, CD4, FOXP3 and miRNA expressions were analyzed.

Results: In our study, hsa-let7c-3p significantly 1,52 (p=0.018) and 1,84 (p=0.0095) fold down- regulated whereas, miR-141-3p was significantly 2,36 (p=0.0006) and 2,24 (p=0.001) fold upregulated in the prostate cancer patients compared to benign prostate hyperplasia in group 1 and 2, respectively. Only CD4 (p=0.004) and PSA (p<0.001) have statistically significant differences among groups when compared to benign prostate hyperplasia. miR-143-p, miR-221-3p, hsa-let7c-3p and miR-17-3p expressions were significantly correlated with regulatory T cell marker FOXP3 expression.

Conclusions: For the first time, we reported significantly altered expression levels of miRNAs (miR-let7c, miR221, miR-146a, miR-141, miR-143, miR17) and correlations between Treg marker FOXP3 in the aggressive prostate cancer patients suggesting that prostate cancer progression might be under the regulation of crosstalk between Tregs and miRNAs.