AKR1B10 expression in benign prostatic hyperplasia and its related mechanism

Inhibitory selectivity to the AKR1B10 and aldose reductase (AR): insight from molecular dynamics simulations and free energy calculations

AKR1B10 is over-expressed in many cancer types and is related to chemotherapy resistance, which makes AKR1B10 a potential anti-cancer target. The high similarity of the protein structure between AKR1B10 and AR makes it difficult to develop highly selective inhibitors against AKR1B10. Understanding the interaction between AKR1B10 and inhibitors is very important for designing selective inhibitors of AKR1B10. In this study, Fidarestat, Zopolrestat, MK184 and MK204 bound to AKR1B10 and AR were used to investigate the selectivity mechanism. The results of MM/PBSA calculations show that van der Waals and electrostatic interaction provide the main contributions of the binding free energy. The hydrogen bonding between residues Y49 and H111 and inhibitors plays a pivotal role in contributing to the high inhibitory activity of AKR1B10 inhibitors. The π-π stacking interaction between residue W112 and inhibitor also plays a key role in the stability of inhibitors and AKR1B10, but W112 should keep its natural conformation to stabilize the inhibitor-AKR1B10 complex. Highly selective AKR1B10 inhibitors should have a bulky moiety like a phenyl group, which can change its binding with ABP in binding with AR and cannot change its binding with AKR1B10. The free energy decomposition shows that residues W21, V48, Y49, K78, W80, H111, R298 and V302 are beneficial to the stability of the inhibitor-AKR1B10. Our work will provide an important in silico basis for researchers to develop highly selective inhibitors of AKR1B10.

Roles of NF-κB activation in benign prostatic hyperplasia and association between NF-κB and HIF-1α

OBJECTIVE

The aim of this study was to elucidate the role of NF-κB activation in benign prostatic hyperplasia (BPH) using immunohistochemistry.

METHODS

Immunohistochemical staining for NF-κB was performed and evaluated, dividing into glands and stroma in 101 human BPH tissues. To evaluate the impacts of NF-κB activation on BPH progression, correlations between NF-κB expression and clinical findings, hormone receptors, and HIF-1α were evaluated.

RESULTS

NF-κB expression was found in 37.6% and 30.7% in glands and stroma of BPH, respectively. Total and T-zone volumes in transrectal ultrasonography were significantly higher in patients with NF-κB activation than those without NF-κB activation in the stroma. However, NF-κB activation of stroma was not correlated with HIF-1α expression and microvessel density. In subgroup analysis based on NF-κB activation, androgen and progesterone receptors of stroma were highly expressed in HIF-1α negative cases than in HIF-1α positive cases. In cases without NF-κB activation, patients with HIF-1α positivity showed a high frequency of diffuse fibrosis than those with HIF-1α negativity (P = 0.001).

CONCLUSION

Taken together, our result showed that NF-κB activation of stroma was significantly correlated with low total and T-zone volumes in transrectal ultrasonography. Diffuse fibrosis was frequently found in patients with NF-κB inactivation and HIF-1α positivity.