Inflammatory suppressive effect of prostate cancer cells with prolonged exposure to transforming growth factor β on macrophage-differentiated cells via downregulation of prostaglandin E2

The bioactive alkaloids identified from Cortex Phellodendri ameliorate benign prostatic hyperplasia via LOX-5/COX-2 pathways

BACKGROUND

The bioactive alkaloids identified from Cortex Phellodendri (CP) were highly effective in treating rats with benign prostatic hyperplasia (BPH). Specifically, lipoxygenase-5 (LOX-5) and cyclooxygenase-2 (COX-2) were identified as two primary targets for alleviating inflammation in BPH rats. However, it remains unknown whether the alkaloid components in CP can interact with the two target proteins.

PURPOSE

To further identify bioactive alkaloids targeting LOX/COX pathways.

METHODS

An affinity-ultrafiltration mass spectrometry approach was employed to screen dual-target LOX-5/COX-2 ligands from alkaloid extract. The structures of bioactive alkaloids were characterized by high-resolution Fourier transform ion cyclotron resonance mass spectrometry. To understand the molecular mechanisms underlying the effects of bioactive alkaloids, the expression levels of LOX-5 and COX-2 in BPH model rats were investigated at both protein and mRNA levels. The LOX-5/COX-2 enzymes activity experiments and molecular docking analysis were performed to fully evaluate the interactions between bioactive alkaloids and LOX-5/COX-2.

RESULTS

After comprehensive analysis, the results showed that bioactive alkaloids could suppress the expression of LOX-5 and COX-2 simultaneously to exert an anti-inflammatory effect on the progression of BPH. In addition, the screened protoberberine, demethyleneberberine was found to exhibit prominent inhibitory activities against both LOX-5 and COX-2 enzymes, palmatine and berberine with moderate inhibitory activities. Molecular docking analysis confirmed that demethyleneberberine could interact well with LOX-5/COX-2.

CONCLUSION

This study is the first to explore the inhibitory effects of bioactive alkaloids from CP on LOX-5 and COX-2 activities in BPH rats. Our findings demonstrate that the bioactive alkaloids from CP can ameliorate BPH via dual LOX-5/COX-2 pathways, which serves as an efficient approach for the discovery of novel drug leads from natural products with reduced side effects.

NF-κB signaling pathway confers neuroblastoma cells migration and invasion ability via the regulation of CXCR4

Background

Accumulating evidence implicates the transcription factor NF-κB as a positive mediator of tumor metastasis, but the molecular mechanism(s) involved in this process remains largely unknown. In this study, we investigated the role of NF-κB signaling pathway in the regulation of CXC chemokine receptor-4 (CXCR4) in neuroblastoma metastasis.

Material/Methods

NF-κB, CXCR4 mRNA and protein expression were measured by RT-PCR, and Western blot. Tumor necrosis factor-a (TNF-α) was used to induce the upregulation of NF-κB and CXCR4. The knockdown of NF-κB and CXCR4 was achieved by PDTC. Transwell assay was used to investigate the role of NF-κB (P65) in neuroblastoma cell migration and invasion. An in vitro co-culture system was established to investigate the role of tumor microenvironment in regulation of the NF-κB signaling pathway.

Results

Over-expression of NF-κB (p65) promoted tumor migration and invasion through the upregulation of CXCR4; however, knockdown of NF-κB(P65) inhibited tumor migration and invasion through blocking the expression of CXCR4. Consistently, in the co-culture system, the expression of CXCR4 was partly dependent on the expression of NF-κB (p65).

Conclusions

Our studies reveal critical roles for the NF-κB signaling pathway in neuroblastoma migration and invasion. The mechanism may be through up-regulation of CXCR4, mediated by the NF-κB signaling pathways. Targeting NF-κB signalling pathways and ultimately CXCR4 could be a strategy in neuroblastoma therapy.