Bo Ryung Park

Polymorphisms of DNA repair genes in Korean hepatocellular carcinoma patients with chronic hepatitis B: Possible implications on survival

BACKGROUND & AIMS We aimed at determining whether single nucleotide polymorphisms (SNPs) of DNA repair genes influence the development and clinical outcomes of hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC). METHODS We evaluated 14 SNPs of eight DNA repair genes in 708 patients with HCC and 388 HBsAg positive controls without HCC. The Kaplan-Meier methods with log-rank test and Cox regression models were used to compare survival of HCC patients according to the genotype. RESULTS The SNP of XRCC4 rs1805377 was significantly associated with decreased risk of HCC development (OR, 0.592; p=0.028) and improved overall survival of patients with HCC (median survival time (MST) of 48, 72, and 89 months for the AA, AG, and GG genotypes, respectively; p=0.044). In addition, SNP of OGG1 rs1053133 was significantly associated with postoperative recurrence (OR, 0.604; p=0.049), tumor differentiation (OR, 0.571; p=0.041), and improved survival of resected HCC (MST of 55 and 108 months for the GG and GC/CC genotypes, p=0.001). The multivariate analysis showed that OGG1 rs1052133, XRCC1 rs25487, ERCC5 rs2018836, ERCC5 rs3818356, and XRCC4 rs1805377 had a significant effect on survival. Moreover, a strong dose-dependent association was observed between the number of putative high-risk genotypes of OGG1, XRCC1, ERCC5, and XRCC4 with the overall survival. The MST of HCC with ≥2 putative high-risk genotypes was significantly prolonged compared to those with ≥3 high-risk genotypes (76 vs. 46 months, respectively, p=0.002). CONCLUSIONS Polymorphisms of DNA repair genes play a potential role in the development, progression, and survival of Korean HCC patients with chronic HBV infection.

Prognostic impact of telomere maintenance gene polymorphisms on hepatocellular carcinoma patients with chronic hepatitis B

Our goal was to determine whether single‐nucleotide polymorphisms (SNPs) of telomere maintenance genes influence the development and clinical outcomes of patients with hepatitis B virus (HBV)‐associated hepatocellular carcinoma (HCC). We evaluated 20 SNPs of five telomere maintenance genes in 702 patients with HCC and 351 hepatitis B virus surface antigen‐positive controls without HCC. Significant SNPs were then validated in an independent cohort of 857 HCC patients and 429 controls. We assessed the association of each SNP with the development of HCC and overall survival through a multivariate Cox proportional analysis. A significantly increased risk of HCC development was identified for the telomerase‐associated protein 1 (TEP1) rs1713449 SNP in both the discovery and replication phases (combined odds ratio = 1.42, P = 9.378 × 10−5). In addition, the TEP1 rs1713449, TEP1 rs872072, protection of telomeres 1 homolog rs7784168, telomerase reverse transcriptase rs13167280, and telomeric repeat binding factor 1 rs2306494 SNPs had a significant effect on the overall survival, and a similar survival effect was validated in the replication cohort. Moreover, there was a significant dose‐dependent association between the number of putatively high‐risk genotypes of the five aforementioned SNPs and overall survival. The median survival time was significantly prolonged for patients with HCC with two or fewer putatively high‐risk genotypes versus those with three or more high‐risk genotypes (85 versus 44 months, log‐rank P = 4.483 × 10−5), and this was demonstrated in the replication cohort (52 versus 37 months, log‐rank P = 0.026). Conclusion: These observations suggest that the SNPs of telomere maintenance genes play a potential role in the development of HCC and the survival of HCC patients with chronic HBV infections. (Hepatology 2014;59:1912–1920)

Prediction of response to entecavir therapy in patients with HBeAg-positive chronic hepatitis B based on on-treatment HBsAg, HBeAg and HBV DNA levels

Summary.  Quantitative hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) assays are emerging as effective tools of on‐treatment predictors of response to antiviral agents, in addition to monitoring serum HBV DNA levels. However, the dynamic relationship between quantitative HBsAg, as well as HBeAg and HBV DNA, and the predictability of subsequent clinical outcomes during entecavir (ETV) therapy remain unclear. Eighty‐two patients with HBeAg‐positive chronic hepatitis B (CHB) received ETV therapy for ≥3 years. Virologic response (VR) after 3 years of ETV therapy was achieved in 73 (89.0%) patients. Among baseline and on‐treatment factors, on‐treatment HBV DNA levels performed better with respect to the prediction of response than HBsAg and HBeAg levels. Especially, the performance of absolute values of HBV DNA with respect to response was superior to HBV DNA decline from the baseline. The best predictive value was an absolute HBV DNA level of 2.3 log10 IU/mL at month 6 (areas under the curve [AUROC], 0.977; 95% CI, 0.940–1.000; P < 0.001). HBeAg seroconversion after 3 years of therapy was achieved in 26 (31.7%) patients. On‐treatment HBeAg levels performed better with respect to the prediction of seroconversion than HBsAg and HBV DNA levels. The best cut‐off value for the HBeAg level at month 12 for the prediction of seroconversion was 0.62 log10 PEIU/mL. Although the HBsAg level at baseline is often used to predict the antiviral potency of entecavir, on‐treatment HBV DNA and HBeAg levels are more helpful for prediction of subsequent clinical outcomes in HBeAg‐positive CHB patients with entecavir treatment.

Clinical course of patients with insufficient viral suppression during entecavir therapy in genotype C chronic hepatitis B

BACKGROUND/AIMS The clinical course of patients with insufficient virologic suppression diagnosed with chronic hepatitis B undergoing entecavir therapy is unclear. METHODS We retrospectively investigated the long-term clinical outcomes of entecavir treatment for more than 12 months in 355 nucleos(t)ide-naïve chronic hepatitis B patients, particularly those with primary non-response or partial virologic response. RESULTS The median duration of entecavir therapy was 40 months (range, 12-64 months). Virologic response was achieved in 315 patients (88.7%). One hundred forty-four (96.6%) of 149 HBeAg-negative patients achieved virologic response. Among 206 HBeAg-positive patients, 52 (25.2%) achieved HBeAg seroconversion. Virologic breakthrough was observed in 7 patients (2.0%). Of these 7 patients, 5 (1.4%) had genotypic resistance to entecavir. Primary non-response and partial virologic response were evident in 6 (1.7%) and 63 (17.7%) patients, respectively. During continuous prolonged entecavir therapy, virologic response of patients with primary non-response and partial virologic response was achieved in 6 (100%) and 28 (44.4%) patients, respectively. CONCLUSION The vast majority of chronic hepatitis B patients in this study achieved virologic response through prolonged entecavir therapy, with only 1.4% chance of viral resistance. Furthermore, all patients with primary non-response were able to achieve virologic response without adjustment of antiviral therapy.

Mitotic checkpoint gene MAD1 in hepatocellular carcinoma is associated with tumor recurrence after surgical resection

Underlying mechanism of mitotic checkpoint gene mitosis arrest deficiency 1 (MAD1) in human hepatocellular carcinoma (HCC) is rarely known.

Tenofovir-based rescue therapy for chronic hepatitis B patients who had failed treatment with lamivudine, adefovir, and entecavir

In the past decade, many chronic hepatitis B (CHB) patients have undergone sequential treatment with lamivudine (LAM), adefovir (ADV), and entecavir (ETV) to manage antiviral resistance or insufficient suppression of HBV‐DNA. Very limited data are available on the efficacy of tenofovir (TDF) rescue regimens in patients with multidrug resistance (MDR).

Efficacy of Tenofovir-based Rescue Therapy in Lamivudine-resistant Chronic Hepatitis B Patients With Failure of Lamivudine and Adefovir Combination

PURPOSE In chronic hepatitis B patients, lamivudine (LAM) and adefovir (ADV) combination therapy is commonly used as a rescue therapy for LAM resistance, but it often results in incomplete viral suppression. We investigated the antiviral efficacy of tenofovir (TDF)/LAM combination therapy versus TDF monotherapy in LAM-resistant chronic hepatitis B (CHB) patients who failed to respond to LAM plus ADV rescue therapy. METHODS Among 108 patients with LAM-resistant CHB who had a partial virologic response (VR) to LAM and ADV combination therapy, Eighty one patients were finally included in this study. FINDINGS Resistance to ADV (ADV-R) was present in 32 patients (39.5%), and the remaining 49 patients (60.5%) had a partial virologic response to LAM/ADV combination (ADV-P). The study subjects were treated with TDF alone (n=15) or TDF/LAM combination (n=66). VR was achieved in 61 patients (75.3%). The rates of VR at 6 and 12 months were not significantly different between TDF monotherapy and TDF/LAM combination therapy groups (46.7 vs. 68.2% at 6 months, and 66.7 vs. 75.9% at 12 months, log-rank P=0.357). Treatment efficacy of TDF alone or TDF/LAM combination was not statistically different according to pre-existing ADV or LAM resistant strains. In multivariate analysis, absolute HBV DNA levels at the start of TDF rescue treatment (P<0.001; OR, 0.556; 95% CI, 0.422-0.731) were the only significantly associated with VR. IMPLICATIONS TDF monotherapy was as effective as TDF/LAM combination therapy in maintaining viral suppression in patients with LAM-resistant patients who failed to respond to LAM/ADV combination therapy.

Medication Nonadherence Increases Hepatocellular Carcinoma, Cirrhotic Complications, and Mortality in Chronic Hepatitis B Patients Treated With Entecavir

OBJECTIVES: Optimal adherence to nucleoside analogue treatment is necessary to achieve undetectable levels of hepatitis B virus (HBV) DNA in patients with chronic hepatitis B (CHB), and to prevent cirrhotic complications. However, any large long‐term follow‐up study has not been investigated the effect of adherence to entecavir (ETV) treatment on specific liver‐related events (LREs), namely, hepatocellular carcinoma (HCC), cirrhotic complications, and mortality. METHODS: This was a 10‐year longitudinal observational study of treatment‐naïve patients with CHB who received ETV treatment. The primary outcome was the cumulative probability of LREs. The cumulative level of adherence to medication was categorized as good (≥90%) or poor (<90%). RESULTS: Data from 894 treatment‐naïve CHB patients who received ETV were analyzed. Overall mean adherence rates were 89.1%. Patients with poor adherence had a higher risk of virologic breakthrough (VBT) (HR, 22.42; 95% CI, 19.57‐52.52; P < 0.001) than those with good adherence. Multivariate analyses showed a higher risk of liver‐related (HR, 14.29; 95% CI, 3.49‐58.47; P < 0.001) or all‐cause (HR, 4.96; 95% CI, 2.19‐11.27; P < 0.001) mortality, HCC (HR, 2.86; 95% CI, 1.76‐4.64; P < 0.001), and cirrhotic complications (HR, 2.86; 95% CI, 1.93‐4.25; P < 0.001) with poor adherence. Medication adherence was further stratified into three groups according to adherence rates of <70%, ≥70 to <90%, and ≥90%. The dose‐response analyses of adherence rates showed that the risk of LREs increased progressively as medication adherence declined. In particular, the unfavorable effects of nonadherence were more pronounced in patients with cirrhosis. CONCLUSIONS: Poor adherence to medication was associated with a higher mortality and greater risk of HCC and cirrhotic complications, particularly among patients with liver cirrhosis.

The expression kinetics of CD137 in chronic hepatitis C patients treated with pegylated-interferon and ribavirin

Abstract Objective. CD137, a member of the tumor necrosis factor receptor family, generates co-stimulatory signals leading to T-cell activation and proliferation for viral eradication. We examined the expression kinetics of CD137 to validate whether it can affect treatment outcomes of chronic hepatitis C (CHC) patients. Methods. The expression of CD137 on peripheral blood mononuclear cells (PBMC) from 50 CHC patients and 20 healthy controls was analyzed by flow cytometry. CD137 expression levels were examined before treatment, and every 4 weeks during treatment until week 24 or 48, and at the 24-week follow-up. Results. CD137 expression on PBMC was significantly lower in CHC patients than controls (15.5 ± 7.8% vs 23.4 ± 5.2%; p < 0.05). Patients with sustained virological response (SVR) showed higher level of CD137 expression on PBMC than treatment failures at week 4 (20.11% vs 10.97%; p < 0.05) and week 12 (15.48% vs 5.74%; p < 0.01). CD137 expression on CD4 T cells was also higher in patients with SVR at week 8 (7.75% vs 3.29%; p < 0.05). CD137 expression on PBMC from patients with SVR recovered to the control level at the 24-week follow-up. In multivariate analysis, the increased expression of CD137 at week 4 and genotype non-1 were significantly associated with SVR. Conclusions. The increased expression of CD137 within 12 weeks after the initiation of interferon therapy might be associated with a successful treatment outcome. Modulation to improve expression of CD137 might improve efficacy of CHC treatment.

Somatic Mutation of ARHI Gene in Hepatocellular Carcinomas

To the Editor: Hepatocellular carcinoma (HCC) is an aggressive form of cancer, is the third leading cause of cancer mortality worldwide [1]. Although several novel therapeutic modalities have been developed in recent years, prognosis of advanced HCC remains poor status. The 5-year relative survival rate is about 7 % and causes more than 600,000 deaths annually worldwide [2]. Until now, little is known about the molecular genetic events in the development and progression of HCC. A Ras homologue member I (ARHI) gene is a maternally imprinted tumor suppressor gene that encodes a 26 kDa GTP-binding protein. It shares 50–60 % amino acid homology with Ras and Rap and is located at human chromosome 1p31 [3]. In contrast to Ras, ARHI inhibits cell growth, motility, and invasion [4, 5]. Recent studies have shown that ARHI is a negative regulator of tumor cell growth in a large number of human cancers [6–8]. For instance, reexpression of ARHI gene into cancer cells that truncates signaling through down-regulation of the cyclin D1 and induction of p21 WAF1/CIP1 [3]. Previous studies have also shown that the expression of ARHI is downreg-ulated in many cancers, including breast carcinomas, ovarian cancers, pancreatic cancer and a few other cancers [9–11]. Furthermore, loss of ARHI expression occur through genetic and/or epigenetic events, including gene mutations, loss of heterozygosity, DNA methylation and histone acetylation [12–15]. All of these findings strongly imply that ARHI is a possible candidate tumor suppressor gene that it may contribute to carcinogenesis. Until now, the important role of ARHI gene in hepatocarcinogenesis has been emphasized. ARHI has pro-apoptotic effects on HCC cell lines [16]. In addition, ARHI overexpression inhibits tumor growth and angiogenesis in HCC xenografts [17]. Furthermore, hypermethylation in ARHI promoter is an important event for the downregulation of HCCs [12]. However, somatic inactivation of the ARHI gene have not been reported in HCC. As a possible inactiva-tion mechanism for ARHI in HCCs, we analyzed somatic mutation of ARHI gene in a series of 38 sporadic HCC tissues from Korean patients. HCC samples and their corresponding non-cancerous liver tissues of 38 patients were evaluated. This study was approved by the Institutional Review Boards at the Ulsan University Hospital. Frozen tissue samples were ground to a very fine powder in liquid nitrogen. Geno-mic DNA was prepared using a procedure based on a protocol described previously [18]. Genomic DNA samples from cancer cells and corresponding non-cancerous liver …