Research

Curative HCC resection or liver transplantation remains the only curative treatment modality for HCC. However, hepatic decompensation, neoplastic progression, and lifelong immunosuppression before and after transplantation increases morbidity and mortality in patients. Polyphenon E (Poly E) is the only green tea extract formula approved by the FDA (IND No. 58367), and our research represents the first attempt to study the effects of Poly E on HCC recurrence following curative resection. Previous studies show that consumption of green tea correlates with lower liver cancer risk in humans. HCC patients shown to have high γ-OHPdG levels will be treated with Poly E. Their γ-OHPdG levels will be determined before and after treatment while they are monitored for recurrence.

Detection and Quantification of an Endogenous DNA Adduct Through MASLD Progression in Circulating Epithelial Cells

There is a need for a more comprehensive group of biomarkers that can not only identify liver injury, but also provide accurate insight into the degree of injury and predisposition to progression to cirrhosis, end-stage liver disease, or HCC. Understanding the molecular changes throughout disease development can help to determine these targets for prediction and prevention. The goal of this study is to detect and quantify γ-OHPdG in circulating epithelial cells (CEC) throughout the progression of Metabolic Dysfunction Associated Liver Disease (MASLD) to understand its correlation to disease progression and HCC development. Further we will quantify oxidative stress through the GSH/GSSG ratio alongside γ-OHPdG to identify a MASLD stage-dependent correlation between oxidative stress and cellular lipid peroxidation (LPO) leading to endogenous DNA adducts. With this information we hope to gain insight into the mechanisms of hepatocarcinogenesis as well as identify clinically relevant biomarkers for liver injury and disease progression. 

Quantification of γ-OHPdG from Formalin-Fixed Paraffin-Embedded Hepatocellular Carcinoma Tissue 

Formalin-fixed paraffin-embedded tissues are among the most abundant biological tissue resources due to their easy and cost-effective storage at room temperature. As such, there is an abundance of available tissue samples for analysis. It has previously been hypothesized that further tissue oxidation occurs in FFPE tissues. This presents a barrier to utilizing FFPE tissues for the quantification of oxidative DNA adducts. DNA adducts are important markers of oxidative stress resulting from α,β-unsaturated aldehydes. DNA adduct quantification can be used as a predictor of metastasis and relapse. To examine the relationship between the duration of FFPE embedding and tissue oxidation of tissue, a series of DNA isolations from paraffin-embedded hepatocellular carcinoma tissue (HCC) were performed at intervals of four weeks. The quantity of adduct assessed from FFPE tissue was compared against a sample isolated from fresh-frozen tissue. Oxidation will be quantified by measuring the amount of y- hydroxy-1,N2- propane deoxyguanosine (y-OHPdG), an endogenously formed DNA adduct that results from lipid peroxidation, using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Preliminary results suggest that DNA purity decreases following isolation from paraffin as compared to isolation from fresh tissue. 

Using two independent sets of clinical samples from 90 and 45 HCC patients, our studies demonstrated that higher levels of γ-OHPdG in HCC biopsy specimens are strongly associated with low survival and low recurrence-free survival, respectively. These results support γ-OHPdG as a promising biologically relevant biomarker for predicting the risk of HCC and its recurrence. In this project, we propose to extend these exciting findings to include a larger patient population to further address questions on γ-OHPdG’s relationships with the underlying etiology of HCC, and clinical predictors for aggressiveness. We also want to compare its levels with those of the adjacent non-tumorous tissues and examine the tumor mutation load. We will develop a non-invasive method for detecting γ-OHPdG in human urine. Our hypothesis is that the adduct levels in urine reflect those in liver DNA. Furthermore, we will conduct an intervention trial with Polyphenon E, an FDA-approved equivalent of Theaphenon E, to prevent HCC recurrence in high-risk patients identified with high liver γ-OHPdG. Our lonγ-term goal is to develop γ-OHPdG as a prognostic biomarker for HCC and its recurrence for intervention trials.