Chemoprevention in African American Men With Prostate Cancer

Molecular mechanisms underlying the epigallocatechin-3-gallate-mediated inhibition of oral squamous cell carcinogenesis

OBJECTIVES

To reveal the mechanisms underlying the epigallocatechin-3-gallate (EGCG)-mediated inhibition of carcinogenesis and the related regulatory signaling pathways.

DESIGN

The effect of EGCG on the proliferation of OSCC cells was examined. SuperPred, ChEMBL, Swiss TargetPrediction, DisGeNET, GeneCards, and National Center for Biotechnology Information databases were used to predict the EGCG target genes and oral leukoplakia (OL)-related, oral submucosal fibrosis (OSF)-related, and OSCC-related genes. The binding of EGCG to the target proteins was simulated using AutoDock and PyMOL. The Cancer Genome Atlas (TCGA) dataset was subjected to consensus clustering analysis to predict the downstream molecules associated with these targets, as well as their potential functions and pathways.

RESULTS

EGCG significantly inhibited OSCC cell proliferation (p < 0.001). By comparing EGCG target genes with genes linked to oral potentially malignant disorder (OPMD) and OSCC, a total of eleven potential EGCG target genes were identified. Furthermore, EGCG has the capacity to bind to eleven proteins. Based on consensus clustering and enrichment analysis, it is suggested that EGCG may hinder the progression of cancer by altering the cell cycle and invasive properties in precancerous lesions of the oral cavity. Some possible strategies for modifying the cell cycle and invasive properties may include EGCG-mediated suppression of specific genes and proteins, which are associated with cancer development.

CONCLUSIONS

This study investigated the molecular mechanisms and signaling pathways associated with the EGCG-induced suppression of OSCC. The identification of specific pharmacological targets of EGCG during carcinogenesis is crucial for the development of innovative combination therapies involving EGCG.

Molecular mechanisms of action of epigallocatechin gallate in cancer: Recent trends and advancement

Epigallocatechin gallate (EGCG), also known as epigallocatechin-3-gallate, is an ester of epigallocatechin and gallic acid. EGCG, abundantly found in tea, is a polyphenolic flavonoid that has the potential to affect human health and disease. EGCG interacts with various recognized cellular targets and inhibits cancer cell proliferation by inducing apoptosis and cell cycle arrest. In addition, scientific evidence has illustrated the promising role of EGCG in inhibiting tumor cell metastasis and angiogenesis. It has also been found that EGCG may reverse drug resistance of cancer cells and could be a promising candidate for synergism studies. The prospective importance of EGCG in cancer treatment is owed to its natural origin, safety, and low cost which presents it as an attractive target for further development of novel cancer therapeutics. A major challenge with EGCG is its low bioavailability which is being targeted for improvement by encapsulating EGCG in nano-sized vehicles for further delivery. However, there are major limitations of the studies on EGCG, including study design, experimental bias, and inconsistent results and reproducibility among different study cohorts. Additionally, it is important to identify specific EGCG pharmacological targets in the tumor-specific signaling pathways for development of novel combined therapeutic treatments with EGCG. The present review highlights the ongoing development to identify cellular and molecular targets of EGCG in cancer. Furthermore, the role of nanotechnology-mediated EGCG combinations and delivery systems will also be discussed.

Chemoprevention of prostate cancer in men with high-grade prostatic intraepithelial neoplasia (HGPIN): a systematic review and adjusted indirect treatment comparison

Background

High-grade prostatic intraepithelial neoplasia (HGPIN) is the precursor or premalignant form of prostate cancer. At least 30% patients with a confirmed HGPIN will develop prostate cancer within 1 year after repeated biopsy. HGPIN patients are the appropriate at-risk population for chemoprevention strategies investigation against prostate cancer. However the commonly used chemoprevention agents that targeted on hormonal imbalance or lifestyle-related factors showed varied results in HGPIN patients.

Methods

Literature searches were conducted in PubMed, EMBASE and Cochrane library according to Cochrane guidelines before January 31^st, 2017. Direct meta-analysis were performed to summarize the efficacy of candidate chemopreventative agents Dutasteride, Flutamide, Toremifene, Selenium, Green tea components, Lycopene and natural food products combination. Adjusted indirect meta-analyses were employed to compare the relative efficacy of these candidate chemoprevention agents head-to-head.

Results

The overall incidence of prostate cancer in HGPIN was slightly decreased by chemoprevention agents (25.7% vs 31.5%, RR = 0.92, 95% CI: 0.83-1.03, P = 0.183), with minor heterogeneity (I² = 22.3%, χ² = 15.08, P = 0.237), but without statistical significance. Subgroup analysis showed that green tea catechins significantly decreased prostate cancer in HGPIN patients (7.60% vs 23.1%, RR = 0.39, 95% CI: 0.16-10.97, P P = 0.044), with moderate heterogeneity (I² = 47.9%, χ² = 1.92, P = 0.166). The adjusted indirect meta-analysis favored green tea catechins over other chemoprevention agents, and significantly when compared to natural food products combination (RR = 0.355, 95% CI: 0.134-0.934).

Conclusion

The overall efficacy of chemoprevention agents in HGPIN patients is limited. But Green tea catechins showed the superiority to decrease prostate cancer in HGPIN patients.