Quantitative assessment of hTERT mRNA expression in dysplastic nodules of HBV-related hepatocarcinogenesis

An overview of risk assessment and monitoring of malignant transformation in cirrhotic nodules

Cirrhotic liver nodules can progress to hepatocellular carcinoma (HCC) through a multi-step carcinogenesis model, with dysplastic nodules being particularly high risk. Currently, monitoring the progression of non-HCC cirrhotic nodules is primarily through dynamic observation, but there is a lack of sensitive, efficient, and convenient methods. Dynamic monitoring and risk evaluation of malignant transformation are essential for timely treatment and improved patient survival rates. Routine liver biopsies are impractical for monitoring, and imaging techniques like ultrasound, computed tomography, and magnetic resonance imaging are not suitable for all patients or for accurately assessing subcentimeter nodules. Identifying serum biomarkers with high sensitivity, specificity, and stability, and developing a multi-index evaluation model, may provide a more convenient and efficient approach to monitoring pathological changes in cirrhotic nodules.

Targeting the NCOA3-SP1-TERT axis for tumor growth in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has a high mortality rate and lacks an effective therapeutic target. Elevated expression of human telomerase reverse transcriptase (TERT) is an important hallmark in cancers, but the mechanism by which TERT is activated differentially in cancers is poorly understood. Here, we have identified nuclear receptor coactivator-3 (NCOA3) as a new modulator of TERT expression and tumor growth in HCC. NACO3 specifically binds to the TERT promoter at the -234 to -144 region and transcriptionally activates TERT expression. NCOA3 promotes HCC cell growth and tumor progression in vitro and in vivo through upregulating the TERT signaling. Knockdown of NACO3 suppresses HCC cell viability and colony formation, whereas TERT overexpression rescues this suppression. NCOA3 interacts with and recruits SP1 binding on the TERT promoter. Knockdown of NCOA3 also inhibits the expression of the Wnt signaling-related genes but has no effect on the Notch signaling-targeting genes. Moreover, NCOA3 is positively correlated with TERT expression in HCC tumor tissues, and high expression of both NCOA3 and TERT predicts a poor prognosis in HCC patients. Our findings indicate that targeting the NCOA3-SP1-TERT signaling axis may benefit HCC patients.

Predictors and Clinical Impacts of Aggravated Left Ventricular Diastolic Dysfunction After Off-Pump Coronary Artery Bypass Grafting

BACKGROUND

To determine the predictors of aggravated left ventricular diastolic dysfunction (LVDD) in patients undergoing off-pump coronary artery bypass grafting (OPCAB) and to compare late outcomes according to the aggravated LVDD.

METHODS AND RESULTS

OPCAB was performed in 1,101 patients (2001-2013). LVDD was classified as normal, mild, moderate or severe. Patients were divided into 2 groups: non-aggravated LVDD (group I) and aggravated LVDD (group II). The primary endpoint was aggravation of LVDD. The secondary endpoint was late mortality and morbidity such as major adverse cardiac and cerebrovascular events (MACCE) related to LVDD aggravation postoperatively. There were 894 patients in group I and 207 in group II. Multivariate analysis revealed that preoperative peripheral artery obstructive disease (PAOD) (P=0.04), renal failure (P<0.01), and A' velocity (P<0.01) anticipated aggravated LVDD. The Cox hazards model revealed that aggravated LVDD was a poor prognostic factor for MACCE (P<0.01) and overall survival (P<0.01). The Kaplan-Meier survival curve showed that aggravated LVDD was related to poor late outcomes (freedom from MACCE, P=0.01; overall survival, P<0.01).

CONCLUSIONS

Aggravated LVDD significantly affects late clinical outcomes after OPCAB and preoperative PAOD, renal failure, and A' velocity might be predictors. (Circ J 2016; 80: 1937-1945).

Diagnostic value of miRNA-96-5p/3p in dysplastic nodules and well-differentiated small hepatocellular carcinoma

AIM

Hepatocarcinogenesis is a multistep process from cirrhosis through low-grade dysplastic nodule, high-grade dysplastic nodule to hepatocellular carcinoma. Differential diagnosis between high-grade dysplastic nodules and early hepatocellular carcinomas is particularly difficult. The present study aims to identify a novel biological marker for differential diagnosis of the two lesions.

METHODS

The expression level of an miRNA pair, miRNA-96-5p and 3p, was assessed by reverse transcription polymerase chain reaction in hepatic tissues.

RESULTS

We showed that mature miRNA-96-5p and passenger strand miRNA-96-3p were differentially expressed in multistep hepatocarcinogenesis. miRNA-96-5p was significantly upregulated from cirrhosis, dysplastic nodules to hepatocellular carcinoma. However, significance of determination of miRNA-96-5p expression level for differential diagnosis between high-grade dysplastic nodule and hepatocellular carcinoma is limited. In contrast, the expression of miRNA-96-3p was detectable in cirrhosis and dysplastic nodules. Also, it was completely undetectable in the majority of hepatocellular carcinomas (30/34, 88.2%). The sensitivity and specificity of miRNA-96-3p negative expression for differential diagnosis of hepatocellular carcinomas from high-grade dysplastic nodules were 88.2% and 84.2%, respectively. In addition, a more specific diagnosis could be carried out by combining miRNA-96-3p with glypican 3, with the specificity of 100%.

CONCLUSION

These findings demonstrated that miRNA-96-3p is a helpful diagnostic biomarker in differential diagnosis between high-grade dysplastic nodules and well-differentiated small hepatocellular carcinomas, especially in combination with glypican 3.

TERT promoter mutations in primary liver tumors

Next-generation sequencing has drawn the genetic landscape of hepatocellular carcinoma and several signaling pathways are altered at the DNA level in tumors: Wnt/β-catenin, cell cycle regulator, epigenetic modifier, histone methyltransferase, oxidative stress, ras/raf/map kinase and akt/mtor pathways. Hepatocarcinogenesis is a multistep process starting with the exposure to different risk factors, followed by the development of a chronic liver disease and cirrhosis precede in the vast majority of the cases the development of HCC. Several lines of evidence have underlined the pivotal role of telomere maintenance in both cirrhosis and HCC pathogenesis. TERT promoter mutations were identified as the most frequent genetic alterations in hepatocellular carcinoma with an overall frequency around 60%. Moreover, in cirrhosis, TERT promoter mutations are observed at the early steps of hepatocarcinogenesis since they are recurrently identified in low-grade and high-grade dysplastic nodules. In contrast, acquisition of genomic diversity through mutations of classical oncogenes and tumor suppressor genes (TP53, CTNNB1, ARID1A…) occurred only in progressed HCC. In normal liver, a subset of HCC can derived from the malignant transformation of hepatocellular adenoma (HCA). In HCA, CTNNB1 mutations predispose to transformation of HCA in HCC and TERT promoter mutations are required in most of the cases as a second hit for a full malignant transformation. All these findings have refined our knowledge of HCC pathogenesis and have pointed telomerase as a target for tailored therapy in the future.

Variations in telomere maintenance and the role of telomerase inhibition in gastrointestinal cancer

Immortalization is an important step toward the malignant transformation of human cells and is critically dependent upon telomere maintenance. There are two known mechanisms to maintain human telomeres. The process of telomere maintenance is either mediated through activation of the enzyme telomerase or through an alternative mechanism of telomere lengthening called ALT. While 85% of all human tumors show reactivation of telomerase, the remaining 15% are able to maintain telomeres via ALT. The therapeutic potential of telomerase inhibitors is currently investigated in a variety of human cancers. Gastrointestinal tumors are highly dependent on telomerase as a mechanism of telomere maintenance, rendering telomeres as well as telomerase potential targets for cancer therapy. This article focuses on the molecular mechanisms of telomere biology and telomerase activation in gastrointestinal cancers and reviews strategies of telomerase inhibition and their potential therapeutic use in these tumor entities.

Promoter hypermethylation of TERT is associated with hepatocellular carcinoma in the Han Chinese population

BACKGROUND

Upstream of the transcription start site (UTSS), hypermethylation of the telomerase reverse transcriptase (TERT) gene has been shown to be associated with tumour progression and a poor prognosis in paediatric brain tumours (Castelo-Branco 2013). It has been inferred that the UTSS region of TERT is a potentially accessible biomarker for various cancers. In this study, we aimed to explore the role of TERT in hepatocellular carcinoma (HCC) and to investigate whether the UTSS region of the TERT promoter shows the same methylation pattern in HCC.

METHODS

We analysed the results of a methylation assay for TERT, including the UTSS region, from 125 paired HCC samples using Mass Array EpiTyper (Sequenom, San Diego, CA, USA). To determine the relationship between TERT promoter methylation status and the TERT expression level, we analysed a validation group of 12 paired HCC samples and acquired the FPKM values for the TERT gene.

RESULTS

Our results showed aberrant methylation of the UTSS region of the TERT promoter in HCC (mean=15.1) compared with the adjacent normal tissues (mean=6.1, P<0.00001). Furthermore, a nearly 56-fold increase in TERT expression from the hypermethylated promoter was found in HCC (P<0.05), indicating a positive relationship between TERT methylation and expression.

CONCLUSIONS

As hypermethylation was positively correlated with high expression of TERT in HCC, TERT is likely to be involved in the aetiology of HCC. Our findings indicate that future studies on TERT might be fruitful.

Telomerase activated thymidine analogue pro-drug is a new molecule targeting hepatocellular carcinoma

BACKGROUND & AIMS

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. Although hepatectomy and transplantation have significantly improved survival, there is no effective chemotherapeutic treatment for HCC and its prognosis remains poor. Sustained activation of telomerase is essential for the growth and progression of HCC, suggesting that telomerase is a rational target for HCC therapy. Therefore, we developed a thymidine analogue pro-drug, acycloguanosyl-5'-thymidyltriphosphate (ACV-TP-T), which is specifically activated by telomerase in HCC cells and investigated its anti-tumour efficacy.

METHODS

First, we verified in vitro whether ACV-TP-T was a telomerase substrate. Second, we evaluated proliferation and apoptosis in murine (Hepa1-6) and human (Hep3B, HuH7, HepG2) hepatic cancer cells treated with ACV-TP-T. Next, we tested the in vivo treatment efficacy in HBV transgenic mice that spontaneously develop hepatic tumours, and in a syngeneic orthotopic murine model where HCC cells were implanted directly in the liver.

RESULTS

In vitro characterization provided direct evidence that the pro-drug was actively metabolized in liver cancer cells by telomerase to release the active form of acyclovir. Alterations in cell cycle and apoptosis were observed following in vitro treatment with ACV-TP-T. In the transgenic and orthotopic mouse models, treatment with ACV-TP-T reduced tumour growth, increased apoptosis, and reduced the proliferation of tumour cells.

CONCLUSIONS

ACV-TP-T is activated by telomerase in HCC cells and releases active acyclovir that reduces proliferation and induces apoptosis in human and murine liver cancer cells. This pro-drug holds a great promise for the treatment of HCC.

Update on precursor and early lesions of hepatocellular carcinomas

CONTEXT

There is increasing evidence to support a multistep model of the process of human hepatocarcinogenesis. Precursor lesions are characterized by the appearance of dysplastic lesions in the form of microscopic dysplastic foci and macroscopic dysplastic nodules. There are 2 types of small hepatocellular carcinoma (HCC) (≤2 cm in diameter): (1) early HCC with an indistinct margin and (2) progressed HCC with a distinct margin. Pathologic diagnostic criteria for early HCC have recently been set up based on a consensus between Eastern and Western pathologists.

OBJECTIVE

To review the nomenclature, pathology, and biomarkers of precursor and early lesions of HCC.

DATA SOURCES

Literature review and illustrations from case materials were used.

CONCLUSIONS

Dysplastic foci are composed of large and small cell changes. Small cell change is considered to be a more advanced precursor lesion than large cell change, and large cell change is a rather heterogeneous lesion that may represent both reactive change and true dysplasia. Dysplastic nodules can be categorized as low or high grade according to the degree of atypia. High-grade dysplastic nodules have been reported to show molecular changes similar to HCC and have a high risk of malignant transformation. Early HCC, which may correspond to microinvasive carcinomas of other organs, is a well-differentiated HCC, and differential diagnosis between early HCC and high-grade dysplastic nodule is difficult. Identification of stromal invasion and application of a panel of markers (glypican-3, heat shock protein 70, and glutamine synthetase) is helpful for diagnosis of early HCC. Detection of precursor lesions of HCC is important in recognizing patients with higher risk of developing HCC, and diagnosis of early HCC can improve patient survival by allowing for early and adequate treatment.

Deregulation of microRNA expression occurs early and accumulates in early stages of HBV-associated multistep hepatocarcinogenesis

BACKGROUND & AIMS

Deregulation of microRNAs (miRNAs) plays an important role in human carcinogenesis. However, miRNA deregulation in the pre-malignant lesions and expression changes during multistep hepatocarcinogenesis remain elusive.

METHODS

In this study, we investigated the expression changes of seven cancer-related miRNAs during the early stages of HBV related hepatocarcinogenesis. miRNA was extracted from formalin fixed paraffin embedded (FFPE) dysplastic nodules (DN), small HCCs, and their corresponding non-tumorous livers. Expression changes of miRNAs were examined by real-time RT-qPCR.

RESULTS

We found that down-regulation of miR-145 and miR-199b and up-regulation of miR-224 were frequently observed in pre-malignant DNs and these changes persisted throughout HCC development. Restoration of miR-145 in both HepG2 and Hep3B HCC cells significantly inhibited cell proliferation and reduced cell migration and cell invasion. Furthermore, these inhibitory functions of miR-145 could be substantially reduced by an anti-miR-145 inhibitor.

CONCLUSIONS

Our results showed that miRNA deregulation was an early event and accumulated throughout the various steps of HBV-associated hepatocarcinogenesis. Our findings also suggest that miR-145 is a candidate tumor suppressive miRNA and may play an important role in HCC development.

Chromosomal instability, telomere shortening, and inactivation of p21(WAF1/CIP1) in dysplastic nodules of hepatitis B virus-associated multistep hepatocarcinogenesis

Systemic analysis for chromosomal instability and inactivation of cell cycle checkpoints are scarce during hepatocarcinogenesis. We studied 24 patients with chronic B viral cirrhosis including 30 cirrhotic regenerative nodules, 35 low-grade dysplastic nodules, 15 high-grade dysplastic nodules, 7 dysplastic nodules with hepatocellular carcinoma foci, and 18 hepatocellular carcinomas. Eight normal livers were studied as the control group. Telomere length and micronuclei were detected by Southern blot and Feulgen-fast green dyeing technique, respectively, and p21(WAF1/CIP1) expression was studied by immunohistochemistry. Micronuclei >1 per 3000 hepatocytes were found in 17% of low-grade dysplastic nodules, 87% of high-grade dysplastic nodules, and 100% of high-grade dysplastic nodules with hepatocellular carcinoma foci and hepatocellular carcinomas in contrast to those of all normal livers, and 90% of cirrhosis showed no micronuclei. The micronuclei index showed a gradual increase during hepatocarcinogenesis and there was a significant increase between cirrhosis and low-grade dysplastic nodules, low-grade dysplastic nodules and high-grade dysplastic nodules, and high-grade dysplastic nodules and hepatocellular carcinomas. Telomere length showed a gradual shortening during hepatocarcinogenesis and a significant reduction was found in high-grade dysplastic nodules (P=0.024) and hepatocellular carcinomas (P=0.031) compared with normal and cirrhotic livers. The micronuclei index was correlated with telomere shortening (P=0.016). The p21(WAF1/CIP1) labeling index was significantly higher in cirrhosis than in normal livers (P=0.024) and markedly decreased in low-grade dysplastic nodules, high-grade dysplastic nodules, and hepatocellular carcinomas compared with cirrhosis (P<0.05). The p21(WAF1/CIP1) labeling index was associated with telomere length (P<0.001) but not micronuclei index. This study shows that telomere shortening, chromosomal instability, and inactivation of p21(WAF1/CIP1) checkpoint function occur in low-grade dysplastic nodules as well as in high-grade dysplastic nodules, and their cooperation is considered to be critical for malignant transformation during hepatitis B virus associated-multistep hepatocarcinogenesis.

Hepatocellular carcinoma (HCC) recurring 10 years after clearance of hepatitis B surface antigen and 20 years after resection of hepatitis B virus-related HCC

A 62-year-old man had been followed up for chronic hepatitis B (HB) since 1973. Hepatocellular carcinoma (HCC) was detected in 1985, at the age of 42 years. Serum HB surface antigen and anti-HB envelope antibody were positive at that time. A right hepatic lobectomy was performed. In 1995, serum HB surface antigen had cleared spontaneously and liver function had normalized. In March 2005, at the age of 62 years, a 1.5-cm diameter hepatic mass was detected in the left lateral segment. At that time, he was seropositive only for anti-HB core antibody. A diagnosis of recurrent HCC was made, and partial hepatectomy was performed. Covalently closed circular HBV DNA was detected in both cancerous and noncancerous tissues by nested polymerase chain reaction (PCR). Cassette-ligation-mediated PCR showed that HBV DNA was integrated into the telomerase reverse transcriptase gene located on chromosome 5p15.

Hepatic precancerous lesions and small hepatocellular carcinoma

Precancerous lesions that may be detected in chronically diseased, usually cirrhotic livers, include: clusters of hepatocytes with atypia and increased proliferative rate (dysplastic foci) that usually represent an incidental finding in biopsy or resection specimens; and grossly evident lesions (dysplastic nodules) that may be detected on radiologic examination. There are two types of small hepatocellular carcinoma (HCC) (defined as HCC that measures less than 2 cm): early HCC, which is well-differentiated and has indistinct margins; and distinctly nodular small HCC, which is well- or moderately differentiated, and is usually surrounded by a fibrous capsule. Precise diagnosis of precancerous and early cancerous lesions by imaging methods is often difficult or impossible. Detection of a dysplastic lesion in a biopsy specimen is a marker of increased risk for HCC development, and warrants increased surveillance. High-grade dysplastic nodules and small HCCs should be treated by local ablation, surgical resection, or liver transplantation.

Detection of telomerase in urine by 3 methods: evaluation of diagnostic accuracy for bladder cancer

PURPOSE

New, noninvasive methods are needed for the diagnosis, followup and screening of patients with bladder cancer. Three methods of detecting telomerase were evaluated in this aspect.

MATERIALS AND METHODS

This study included 200 patients diagnosed with bladder carcinoma, 85 with benign bladder lesions and 30 healthy individuals who served as the control group. All underwent serological schistosomiasis antibody assay in serum, urine cytology and estimation of relative telomerase activity by telomeric repeat amplification protocol, human telomerase RNA by reverse transcriptase-polymerase chain reaction and human telomerase reverse transcriptase by real-time reverse transcriptase-polymerase chain reaction in urothelial cells from voided urine.

RESULTS

The concordance between the positive rates of telomerase detected by the 3 methods was high (90% to 95%). Results were significantly higher in the malignant group than in the benign and control groups. There was a significant difference among the results of the 3 methods in relation to different clinicopathological factors. Overall the sensitivity of human telomerase reverse transcriptase for detecting bladder cancer was the highest compared to that of human telomerase RNA, relative telomerase activity and urine cytology (96%, 92%, 75% and 75%, respectively). Combinations of telomerase results with urine cytology were not useful except in cases of relative telomerase activity.

CONCLUSIONS

Detection of human telomerase reverse transcriptase in urine by real-time polymerase chain reaction, followed by human telomerase RNA by reverse transcriptase-polymerase chain reaction, improves sensitivity and specificity for the diagnosis of bladder cancer. However, regarding cost-effectiveness, human telomerase RNA is superior.

Ductular reaction is helpful in defining early stromal invasion, small hepatocellular carcinomas, and dysplastic nodules

BACKGROUND

Stromal invasion is 1 of the main features used to distinguish high-grade dysplastic nodules (DNs) from well-differentiated hepatocellular carcinomas (HCCs). The authors hypothesized that ductular reaction (DR) takes place around noninvasive hepatocellular nodules but not within the stroma contiguous to invasive HCC.

METHODS

DR/cytokeratin 7 (CK7)-positive patterns were evaluated in 105 resected small hepatic nodules according to the level of invasion. The nodules were classified histologically prior to immunostaining as noninvasive (large regenerative nodules, low-grade DNs, and high-grade DNs), minimally invasive (early HCCs with a vaguely nodular type), and overtly invasive (typical HCCs with a distinctly nodular type) in a review by expert pathologists, the current gold standard. Intranodular DR (inner DR) and DR around the nodule periphery (outer DR) were assessed separately on a semiquantitative scale from 0 to 4+.

RESULTS

DR was 3 or 4+ in the majority of noninvasive nodules (inner DR, 81%; outer DR, 91%), whereas DR was 0 or 1+ in overtly invasive HCCs (inner DR, 96%; outer DR, 81%). Minimally invasive HCCs showed an intermediate DR pattern (2 or 3+ inner DR, 75%; 2+ outer DR, 67%). DR characteristically was absent at the stromal-invasive, leading edge of tumor cells in both minimally invasive HCCs (focal loss of DR/CK7) and overtly invasive HCCs (diffuse loss of DR/CK7). The DR patterns in 41 needle-biopsy samples were similar to the patterns observed in resected nodules.

CONCLUSIONS

DR/CK7 immunostaining may help to identify small foci of invasion and to distinguish noninvasive, high-grade DNs from both minimally invasive and overtly invasive HCCs.

Telomere shortening and inactivation of cell cycle checkpoints characterize human hepatocarcinogenesis

Telomere shortening and inactivation of cell cycle checkpoints characterize carcinogenesis. Whether these molecular features coincide at specific stages of human hepatocarcinogenesis is unknown. The preneoplasia-carcinoma sequence of human HCC is not well defined. Small cell changes (SCC) and large cell changes (LCC) are potential precursor lesions. We analyzed hepatocellular telomere length, the prevalence of DNA damage, and the expression of p21 and p16 in biopsy specimens of patients with chronic liver disease (n = 27) that showed different precursor lesions and/or HCC: liver cirrhosis (n = 25), LCC (n = 26), SCC (n = 13), and HCC (n = 13). The study shows a decrease in telomere length in nondysplastic cirrhotic liver compared with normal liver and a further significant shortening of telomeres in LCC, SCC, and HCC. HCC had the shortest telomeres, followed by SCC and LCC. Hepatocytes showed an increased p21 labeling index (p21-LI) at the cirrhosis stage, which remained elevated in most LCC. In contrast, most SCC and HCC showed a strongly reduced p21-LI. Similarly, p16 was strongly expressed in LCC but reduced in SCC and not detectable in HCC. gammaH2AX-DNA-damage-foci were not detected in LCC but were present in SCC and more frequently in HCC. These data indicate that LCC and SCC represent clonal expansions of hepatocytes with shortened telomeres.

CONCLUSION

The inactivation of cell cycle checkpoints coincides with further telomere shortening and an accumulation of DNA damage in SCC and HCC, suggesting that SCC represent more advanced precursor lesions compared with LCC.

Usefulness of cancer-testis antigens as biomarkers for the diagnosis and treatment of hepatocellular carcinoma

Despite advances in our cellular and molecular knowledge, hepatocellular carcinoma (HCC) remains one of the major public health problems throughout the world. It is now known to be highly heterogeneous: it encompasses various pathological entities and a wide range of clinical behaviors, and is underpinned by a complex array of gene alterations that affect supra-molecular processes.

Four families of HCC tumour markers have been recently proposed: a) onco-fetal and glycoprotein antigens; b) enzymes and iso-enzymes; c) cytokines and d) genes. A category of tumour-associated antigens called cancer-testis (CT) antigens has been identified and their encoding genes have been extensively investigated. CT antigens are expressed in a limited number of normal tissues as well as in malignant tumors of unrelated histological origin, including the liver. Given that cancers are being recognized as increasingly complex, we here review the role of CT antigens as liver tumour biomarkers and their validation process, and discuss why they may improve the effectiveness of screening HCC patients and help in determining the risk of developing HCC.

Telomerase activation in human hepatocarcinogenesis

Active telomerase is present in the majority of malignant human tumors, including most cases of hepatocellular carcinoma (HCC). Telomerase reverse transcriptase (hTERT), the catalytic subunit of telomerase, has been found to be expressed in HCCs, dysplastic (precancerous) nodules (DNs), and regenerative nodules arising in cirrhosis. In a study reported in this issue of the journal, hTERT mRNA levels were assessed by quantitative real-time RT-PCR in various nodular lesions dissected from liver specimens of patients with chronic hepatitis B. High levels of hTERT mRNA were present in HCCs, high-grade DNs, and occasional low-grade DNs, whereas low levels were found in normal livers, livers with chronic hepatitis B (with or without cirrhosis), large regenerative nodules, and most low-grade DNs. Therefore, quantitative assessment of hTERT mRNA may provide a useful adjunct to histopathologic evaluation of large hepatic nodules. Indeed, emerging data from gene expression analyses of DNs and HCCs suggest that hTERT can be included in sets of select genes that provide "molecular signatures" with utility in the diagnosis and management of nodular hepatic lesions. Most importantly, tackling the mechanisms of telomerase activation may provide new means of therapy for HCC and other cancers.