Abnormal expression of HNRNPA3 in multistep hepatocarcinogenesis

Hepatocarcinogenesis is a multistep process involving progression from cirrhosis, to low-grade dysplastic nodule, to high-grade dysplastic nodule (HGDN) and, eventually, to hepatocellular carcinoma (HCC). Early detection of HCC is challenging as the differential diagnosis between HGDN and early HCC (eHCC) is difficult. The aim of the present study was to identify a novel biomarker to specifically differentiate between HGDN and eHCC, which may facilitate early diagnosis of HCC. Immunohistochemistry was performed to determine the expression of heterogeneous nuclear ribonucleoprotein A3 (HNRNPA3) in cirrhosis, dysplastic nodules (DNs), well-differentiated HCC and progressed HCC. The staining was evaluated by assigning a staining intensity score of 0–3 and a percentage of positively stained cells score of 0–4. Receiver operator characteristic (ROC) curve analysis was used to assess the ability of HNRNPA3 expression to differentiate between DNs and HCC. HNRNPA3 expression increased in a stepwise trend in non-tumor hepatic tissue, DNs, eHCC and progressed HCC. ROC curves revealed that HNRNPA3 expression could be used to differentiate between HGDN and eHCC, particularly in combination with glypican 3 (GPC3), with a specificity of 100%. Moreover, HNRNPA3 expression was associated with HCC differentiation. In addition, high expression of HNRNPA3 was found to be associated with poor survival rates in patients with HCC. These findings demonstrated that HNRNPA3 combined with GPC3 is a helpful diagnostic biomarker in the differential diagnosis during the multistep process of hepatocarcinogenesis, particularly in the differential diagnosis between HGDN and eHCC. To the best of our knowledge, this is the first study to report the significance of HNRNPA3 in hepatocarcinogenesis and its potential role in carcinogenesis.

Comparison of pulsed and oscillating gradient diffusion-weighted MRI for characterizing hepatocellular nodules in liver cirrhosis: ex vivo study in a rat model

BACKGROUND

In contrast to classical pulsed gradient diffusion-weighted MRI, oscillating gradient diffusion-weighted MR imaging (DWI) is sensitive to short distance diffusion changes at the intracellular level.

PURPOSE

To compare the diagnostic performance of pulsed and oscillating DWI for characterizing hepatocellular nodules in a rat model of hepatic cirrhosis.

STUDY TYPE

Prospective, experimental study.

ANIMAL MODEL

Cirrhosis was induced by weekly intraperitoneal injection of diethylnitrosamine in Wistar rats.

FIELD STRENGTH/SEQUENCE

Ex vivo liver MRI was performed at 7T with T₁ -weighted, T₂ -weighted, pulsed, and oscillating gradient diffusion-weighted sequences.

ASSESSMENT

Apparent diffusion coefficient from pulsed (ADC_pulsed ) and oscillating gradient (ADC_oscillating ) sequences was calculated in 82 nodules identified on the T₁ /T₂ -weighted images and on pathological examination. Two pathologists classified the nodules in three categories: benign (regenerative and low-grade dysplastic nodules), with intermediate malignancy (high-grade dysplastic nodules and early hepatocellular carcinomas) and overtly malignant (progressed hepatocellular carcinomas).

STATISTICAL TESTS

Differences between groups were assessed with Kruskal-Wallis and Mann-Whitney tests.

RESULTS

ADC, mainly ADC_oscillating , increased in the group of nodules with intermediate malignancy (ADC_pulsed : 0.75 ± 0.25 × 10^-3 mm² /s vs. 0.64 ± 0.07 × 10^-3 mm² /s in benign nodules, P = 0.025; ADC_oscillating : 0.81 ± 0.20 × 10^-3 mm² /s vs. 0.65 ± 0.13 × 10^-3 mm² /s, P = 0.0008) and ADC_pulsed decreased in the group of progressed hepatocellular carcinomas (ADC_pulsed : 0.60 ± 0.08 × 10^-3 mm² /s, P = 0.042; ADC_oscillating : 0.68 ± 0.08 × 10^-3 mm² /s, P = 0.1).

DATA CONCLUSION

ADC during hepatocarcinogenesis in rats increased in nodules with intermediate malignancy and decreased in progressed hepatocellular carcinomas. Our results suggest that oscillating gradient DWI is more sensitive to the early steps of hepatocarcinogenesis and might be useful for differentiating between high-grade dysplastic nodules / early hepatocellular carcinomas and regenerating nodules / low-grade dysplastic nodules.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2020;51:1065-1074.

Hepatocellular carcinoma: a review of diagnostic challenges for the pathologist

Histopathologists retain a critical role in the diagnosis and management of hepatocellular carcinoma (HCC). HCC arises usually but not exclusively in a background of advanced-stage chronic liver disease. The histological diagnosis of HCC poses many challenges particularly when dealing with liver biopsy specimens due to the heterogeneity of HCC and the difficulty to confirm hepatocellular differentiation in some instances. Primary liver tumors should be considered as a continuum with typical hepatocellular and cholangiocarcinoma at the two ends and a whole range of tumors showing both hepatocellular and cholangiocellular differentiation with or without an associated progenitor/stem cell component in the middle. Characterization of combined (or mixed) hepatocellular-cholangiocarcinoma can be very challenging. In advanced-stage chronic liver disease, the main challenge for the histopathologist is still to differentiate between HCC and its precursors, although this is rarely critical in the clinical setting at present. HCC originating in non-cirrhotic livers needs to be differentiated from other primary and extrahepatic tumors and from hepatocellular adenoma, bearing in mind that progression to malignancy is more through a continuum that watertight histological categories.

Primary Liver Cancers-Part 1: Histopathology, Differential Diagnoses, and Risk Stratification

Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) are the 2 most common primary malignant liver tumors, with hepatocellular and bile ductular differentiation, respectively. This article reviews the key histopathological findings of these 2 primary liver cancers and includes a review of the role of ancillary testing for differential diagnosis, risk stratification according to the American Joint Committee on Cancer (AJCC) staging recommendation, and a review of precancerous lesions. A literature review was conducted to identify articles with information relevant to precancerous precursors, current histopathological classification, ancillary testing, and risk stratification of primary malignant liver tumors. The histomorphology of normal liver, preinvasive precursors, primary malignancies, and morphological variants, and the utilization of ancillary tests for the pathological diagnosis are described. Dysplastic nodules are the preinvasive precursors of HCC, and intraductal papillary neoplasms of bile ducts and biliary intraepithelial neoplasia are the preinvasive precursors of CC. Benign liver nodules including focal nodular hyperplasia and adenomas are included in this review, since some forms of adenomas progress to HCC and often they have to be differentiated from well-differentiated HCC. A number of morphological variants of HCC have been described in the literature, and it is necessary to be aware of them in order to render the correct diagnosis. Risk stratification is still dependent on the AJCC staging system. The diagnosis of primary liver carcinomas is usually straightforward. Application of the appropriate ancillary studies aids in the differential diagnosis of difficult cases. The understanding of the carcinogenesis of these malignancies has improved with the standardization of the pathological classification of preinvasive precursors and studies of the molecular pathogenesis. Risk stratification still depends on pathological staging.

Hepatocellular Carcinoma in Fanconi-Bickel Syndrome

Fanconi-Bickel syndrome is a rare autosomal recessive disorder due to mutations in the facilitative glucose transporter 2 ( GLUT2 or SLC2A2) gene resulting in excessive glycogen storage predominantly in the liver and kidney. Previous case reports of this condition have described liver biopsies with glycogen storage and variable steatosis and/or fibrosis. Unlike in other types of glycogen storage disease, hepatocellular adenomas and carcinomas have not been described to date in this syndrome. A 6-year-old boy with consanguineous parents had short stature, poorly controlled rickets, hepatosplenomegaly, and renal tubular dysfunction clinically consistent with Fanconi-Bickel Syndrome. Sequencing of the SLC2A2 gene showed a homozygous variant of unknown significance [c.474A > C (p.Arg158Ser)] causing a missense mutation in an evolutionarily conserved residue. An incidental single hepatic lesion was discovered on imaging, and subsequent resection showed a 2.6 cm well-differentiated hepatocellular carcinoma with moderate atypia, diffuse immunoreactivity for glypican-3, and nuclear b-catenin, and with focal complete loss of the reticulin framework. The non-neoplastic liver showed marked glycogen accumulation with mild periportal fibrosis, rare bridging fibrosis, and no regenerative or adenomatous nodules. By electron microscopy, tumor cells had pleomorphic nuclei, prominent nucleoli, and scant cytoplasm with numerous mitochondria. Well-developed canaliculi were occasionally seen. The non-neoplastic liver showed glycogenosis with abundant cytoplasmic free (non-membrane bound) glycogen. Hepatocellular carcinoma should be considered as a possible complication of Fanconi-Bickel syndrome. This well differentiated carcinoma did not appear to be associated with hepatic adenomatosis as has been described in some hepatocellular carcinomas associated with other hepatic glycogen storage disorders. The nuclear beta-catenin immunoreactivity indicates a role for the Wnt signaling pathway in the pathogenesis of this tumor.

Characterization of small (≤3 cm) hepatic lesions with atypical enhancement feature and hypointensity in hepatobiliary phase of gadoxetic acid-enhanced MRI in cirrhosis: A STARD-compliant article

It is difficult to characterize the nodular lesions in cirrhotic liver if typical enhancement pattern is not present on dynamic contrast-enhanced imagings. Although the signal intensity of the hepatobiliary phase in gadoxetic acid-enhanced magnetic resonance imaging (MRI) is helpful for characterization of the lesions, some dysplastic nodules may also exhibit low signal intensity in the hepatobiliary phase. We aimed to assess the usefulness of gadoxetic acid (Gd-EOB-DTPA)-enhanced MRI including diffusion-weighted imaging (DWI) for differentiation between atypical small hepatocellular carcinomas (HCCs) and dysplastic nodules showing low signal intensity (SI) in the hepatobiliary phase, and to evaluate the MRI findings in determining the histological grade of atypical HCCs in patients with cirrhosis.A total of 43 cirrhotic patients with a small (≤3 cm) liver nodule (n = 25, HCC; n = 18, dysplastic nodule) who underwent Gd-EOB-DTPA-enhanced MRI and pathologic confirmation were retrospectively reviewed. Atypical HCC was defined as not showing arterial hyperenhancement and delayed washout on dynamic MRI.High SI on both T2WI and DWI (sensitivity 80.0%, specificity 100%, positive predictive value 100%, negative predictive value 78.3%) was the most specific feature to differentiate atypical HCCs from dysplastic nodules. High SI on both T2WI and DWI (100% vs 61.5%, P = .039) or low SI on pre-enhanced T1WI (83.3% vs 30.8%, P = .021) was more frequent observed in Edmonson grade II-III HCCs compared with those in grade I HCCs.The combination of DWI and T2WI is most useful for the differentiation of atypical small HCCs from dysplastic nodules showing low SI in the hepatobiliary phase. Combination of DWI and T2WI or pre-enhanced T1WI seems to be useful for predicting the histological grade of atypical HCCs.

Ongoing challenges in the diagnosis of hepatocellular carcinoma

In 2001, the European Association for the Study of the Liver (EASL) endorsed the possibility of achieving a non-invasive diagnosis of Hepatocellular Carcinoma (HCC) for the first time. Since then, various refinements of the criteria and techniques capable of achieving this diagnosis and the role of plasma and tissue oncomarkers have been reported in the literature and have been accepted to different extents in various geographical areas. Such tools can also potentially imply prognostic significance. The present article critically discusses some of the most relevant and debated challenges which have emerged in this field, including the role of contrast-enhanced ultrasound, and of hepatocyte-specific magnetic resonance contrast agents, the pitfall of transient hepatic attenuation differences, the reliability of biopsy and the status of biomarkers.

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.

Gadoxetate Disodium-Enhanced MRI to Differentiate Dysplastic Nodules and Grade of Hepatocellular Carcinoma: Correlation With Histopathology. AJR Am J Roentgenol. 2015;205:546-553. [PMID: 26295640 DOI: 10.2214/ajr.14.12716]

OBJECTIVE

The objective of our study was to determine quantitative differences to differentiate low-grade from high-grade dysplastic nodules (DNs) and low-grade from high-grade hepatocellular carcinomas (HCCs) using gadoxetate disodium-enhanced MRI.

MATERIALS AND METHODS

A retrospective study of 149 hepatic nodules in 127 consecutive patients who underwent gadoxetic acid-enhanced MRI was performed. MRI signal intensities (SIs) of the representative lesion ROI and of ROIs in liver parenchyma adjacent to the lesion were measured on unenhanced T1-weighted imaging and on dynamic contrast-enhanced MRI in the arterial, portal venous, delayed, and hepatobiliary phases. The relative SI of the lesion was calculated for each phase as the relative intensity ratio as follows: [mass SI / liver SI].

RESULTS

Of the 149 liver lesions, nine (6.0%) were low-grade DNs, 21 (14.1%) were high-grade DNs, 83 (55.7%) were low-grade HCCs, and 36 (24.2%) were high-grade HCCs. The optimal cutoffs for differentiating low-grade DNs from high-grade DNs and HCCs were an unenhanced to arterial SI of ≥ 0 or a relative SI on T2-weighted imaging of ≤ 1.5, with a positive predictive value (PPV) of 99.2% and accuracy of 88.6%. The optimal cutoffs for differentiating low-grade HCCs from high-grade HCCs were a relative hepatobiliary SI of ≤ 0.5 or a relative T2 SI of ≥ 1.5, with a PPV of 81.0% and an accuracy of 60.5%.

CONCLUSION

Gadoxetate disodium-enhanced MRI allows quantitative differentiation of low-grade DNs from high-grade DNs and HCCs, but significant overlap was seen between low-grade HCCs and high-grade HCCs.

Diagnosing Borderline Hepatic Nodules in Hepatocarcinogenesis: Imaging Performance. AJR Am J Roentgenol. 2015;205:10-21. [PMID: 26102378 DOI: 10.2214/ajr.14.12655]

OBJECTIVE

The purposes of this article are to describe the pathologic and radiologic features of small nodular lesions and to offer insight into the multistep process of hepatocarcinogenesis by describing the progression of imaging changes that link dysplastic nodules and early hepatocellular carcinoma, (HCC) to small HCC that has progressed.

CONCLUSION

Nodules larger than 1 cm found during ultrasound surveillance of a cirrhotic liver should be investigated further with diagnostic imaging. Contrast-enhanced CT and dynamic MRI are the primary diagnostic studies for the diagnosis of HCC; contrast-enhanced ultrasound can be used as an alternative test. If a nodule has the typical hallmark of hypervascularity in the hepatic arterial phase with washout in the portal venous or delayed phase, a definitive diagnosis of HCC can be made. Nodules found during ultrasound surveillance that are smaller than 1 cm can be followed with ultrasound examinations at intervals of 3-6 months.

Circulating microRNAs as biomarkers for diagnosis of early hepatocellular carcinoma associated with hepatitis B virus

Hepatocarcinogenesis is a multistep process that evolves from cirrhosis or dysplastic nodule (DN), and eventually leads to overt hepatocellular carcinoma (HCC). Differentiation between early HCC and DN is an important issue in the clinical setting. This study aims to investigate the potential of circulating microRNA (miRNA) levels in the diagnosis of early HCC. RNA was extracted from sera of 30 chronic hepatitis B patients with pathologically proven DN and 120 age- and sex-matched patients with early HCC. Paired samples were collected from ten patients with DN who developed overt HCC in the follow-up. A panel of ten cancer-associated miRNAs was analyzed by quantitative real-time reverse-transcription polymerase chain reaction. Serum levels of miR-16, miR-122, miR-221, let-7b and miR-15b were significantly lower in patients with DN than in the HCC group. When DN progressed to overt HCC, serum miR-122, miR-let-7b and miR-15b levels increased significantly (p = 0.046, 0.043 and 0.044, respectively). As a single marker, α-fetoprotein (AFP) and miR-122 as well as let-7b had the similar performance for differentiate HCC from DN. As limited to subjects with normal AFP, let-7b resulted in a sensitivity of 84.8% and a specificity of 50% in separating HCC and DN with a cutoff value of 3.5 (p = 0.001). In conclusion, miR-122 and let-7b, which are upregulated in the serum of early-HCC patients, can be useful markers for differentiating early HCC from DN in chronic hepatitis B patients.

Genomic losses at 5q13.2 and 8p23.1 in dysplastic hepatocytes are common events in hepatitis B virus-related hepatocellular carcinoma

Chromosomal loci with genomic imbalances are frequently identified in hepatocellular carcinoma (HCC). Greater than two-thirds of hepatitis B virus (HBV)-related HCCs originate from liver cirrhosis following a duration of up to two decades. However, it is unclear whether these genomic imbalances occur and accumulate in dysplastic hepatocytes of the cirrhotic liver during the progression from regenerated nodules to preneoplastic lesions, including dysplastic nodules (DN). In the present study, high-grade DNs (HGDNs) of HBV-related liver cirrhosis were screened to identify loci with genomic imbalances, and the frequency of the identified loci in a group of HCCs was analyzed in order to determine whether there may be a genetic link between liver cirrhosis and HCC. Genomic DNA was extracted from six HGDNs of two cases of HBV-related liver cirrhosis and subjected to array comparative genomic hybridization (CGH) analysis with a NimbleGen 720K microarray. Loci with the most frequently observed genomic imbalances in DNs were further analyzed in 83 cases of HCC by differential polymerase chain reaction (PCR) and quantitative PCR. The array CGH analysis revealed that the majority of genomic imbalances in the HGDNs were genomic losses of small segments, with loss of heterozygosity (LOH) at 5q13.2 and 8p23.1 identified most frequently. Of the 83 HCC cases, 30 (36.1%) cases were identified with LOH at 5q13.2, where known tumor-associated genes are located, including general transcription factor IIH subunit 2 (GTF2H2), baculoviral IAP repeat-containing protein 1 (BIRC1) and occludin (OCLN). LOH frequency at 8p23.1 in HCC was 61.29% (D8S1130) and 68.4% (D8S503) respectively, similar to the results obtained in previous studies. In conclusion, the results of the present study provided evidence that genomic losses at 5q13.2 and 8p23.1 identified in dysplastic hepatocytes of the cirrhotic liver are common events in HCC. HCC-associated chromosomal abnormalities may occur and accumulate in preneoplastic lesions of liver cirrhosis.

Pleiotropic effects of methionine adenosyltransferases deregulation as determinants of liver cancer progression and prognosis

Downregulation of liver-specific MAT1A gene, encoding S-adenosylmethionine (SAM) synthesizing isozymes MATI/III, and upregulation of widely expressed MAT2A, encoding MATII isozyme, known as MAT1A:MAT2A switch, occurs in hepatocellular carcinoma (HCC). Being inhibited by its reaction product, MATII isoform upregulation cannot compensate for MATI/III decrease. Therefore, MAT1A:MAT2A switch contributes to decrease in SAM level in rodent and human hepatocarcinogenesis. SAM administration to carcinogen-treated rats prevents hepatocarcinogenesis, whereas MAT1A-KO mice, characterized by chronic SAM deficiency, exhibit macrovesicular steatosis, mononuclear cell infiltration in periportal areas, and HCC development. This review focuses upon the pleiotropic changes, induced by MAT1A/MAT2A switch, associated with HCC development. Epigenetic control of MATs expression occurs at transcriptional and post-transcriptional levels. In HCC cells, MAT1A/MAT2A switch is associated with global DNA hypomethylation, decrease in DNA repair, genomic instability, and signaling deregulation including c-MYC overexpression, rise in polyamine synthesis, upregulation of RAS/ERK, IKK/NF-kB, PI3K/AKT, and LKB1/AMPK axis. Furthermore, decrease in MAT1A expression and SAM levels results in increased HCC cell proliferation, cell survival, and microvascularization. All of these changes are reversed by SAM treatment in vivo or forced MAT1A overexpression or MAT2A inhibition in cultured HCC cells. In human HCC, MAT1A:MAT2A and MATI/III:MATII ratios correlate negatively with cell proliferation and genomic instability, and positively with apoptosis and global DNA methylation. This suggests that SAM decrease and MATs deregulation represent potential therapeutic targets for HCC. Finally, MATI/III:MATII ratio strongly predicts patients' survival length suggesting that MAT1A:MAT2A expression ratio is a putative prognostic marker for human HCC.

Promoter methylation of E-cadherin in hepatocellular carcinomas and dysplastic nodules

In order to clarify the significance of E-cadherin methylation in multistep hepatocarcinogenesis, we examined the methylation status of the E-cadherin promoter region, using methylation-specific polymerase chain reaction in 64 hepatocellular carcinomas (HCCs) and 13 dysplastic nodules (DNs), and correlated these results with E-cadherin protein expression and clinicopathologic factors of HCCs. Promoter methylation was detected in 1 of 13 (7.7%) DNs, in 5 of 13 (38.5%) Edmondson and Steiner grade I HCCs, and in 27 of 51 (52.9%) grade II or III HCCs, and a significant correlation was observed between the methylation status and the stepwise progression of hepatocarcinogenesis (p=0.004). Reduced E-cadherin immunoreactivity was found in 18 of 64 (28%) HCCs, but in none of DNs. E-cadherin methylation status in HCCs was significantly correlated with microvascular invasion (p=0.02) and tumor recurrence (p=0.04), but not with reduced E-cadherin immunoreactivity. The Kaplan-Meier method showed that methylation status did not have a significant influence on the recurrence-free survival of HCC patients (p=0.15). Our results indicate that methylation of the E-cadherin promoter region is a frequent event in HCC, which may play an important role in the stepwise progression of hepatocarcinogenesis. And the promoter methylation of E-cadherin in HCC was found to be significantly correlated with microvascular invasion and recurrence.