Small hyperechoic nodules in chronic liver diseases include hepatocellular carcinomas with low cyclin D1 and Ki-67 expression

A huge hepatic angiomyolipoma with growth during 5 years of follow-up

A 45-year-old woman was referred to our hospital with a huge liver tumor that had been diagnosed as a hepatic angiomyolipoma (HAML) 5 years previously. At the time of referral, it had enlarged from 12 to 20 cm within the previous 5 years and become symptomatic. Enhanced computed tomography revealed a very large, well-defined, low-density mass occupying the entire right lobe of the liver. The patient underwent right hemi-hepatectomy. The resected specimen weighed 1620 g and measured 20 × 14 × 8 cm. The pathological diagnosis was confirmed as benign HAML. The estimated growth rate of this tumor was 44% per year with a doubling time of 826 days. Although the majority of HAMLs are stable lesions, resection should perhaps be considered when the tumor is known to be growing and exceeds 6 cm in diameter, even if it has been diagnosed as benign.

LI-RADS® ancillary features on CT and MRI

The Liver Imaging Reporting and Data System (LI-RADS) uses an algorithm to assign categories that reflect the probability of hepatocellular carcinoma (HCC), non-HCC malignancy, or benignity. Unlike other imaging algorithms, LI-RADS utilizes ancillary features (AFs) to refine the final category. AFs in LI-RADS v2017 are divided into those favoring malignancy in general, those favoring HCC specifically, and those favoring benignity. Additionally, LI-RADS v2017 provides new rules regarding application of AFs. The purpose of this review is to discuss ancillary features included in LI-RADS v2017, the rationale for their use, potential pitfalls encountered in their interpretation, and tips on their application.

Wee1 Kinase Inhibitor AZD1775 Radiosensitizes Hepatocellular Carcinoma Regardless of TP53 Mutational Status Through Induction of Replication Stress

PURPOSE

Wee1 kinase inhibitors are effective radiosensitizers in cells lacking a G1 checkpoint. In this study we examined the potential effect of Wee1 kinase inhibition on inducing replication stress in hepatocellular carcinoma (HCC).

METHODS AND MATERIALS

Five independent datasets from the Oncomine database comparing gene expression in HCC compared to normal tissue were combined and specific markers associated with Wee1 sensitivity were analyzed. We then performed a series of in vitro experiments to study the effect of Wee1 inhibition on irradiated HCC cell lines with varying p53 mutational status. Clonogenic survival assays and flow cytometry using anti-γH2AX and phospho-histone H3 antibodies with propidium iodide were performed to study the effect of AZD1775 on survival, cell cycle, and DNA repair. Additionally, nucleoside enriched medium was used to examine the effect of altering nucleotide pools on Wee1 targeted radiation sensitization.

RESULTS

Our analysis of the Oncomine database found high levels of CDK1 and other cell cycle regulators indicative of Wee1 sensitivity in HCC. In our in vitro experiments, treatment with AZD1775 radiosensitized and chemosensitized Hep3B, Huh7, and HepG2 cell lines and was associated with delayed resolution of γH2AX foci and the induction of pan-nuclear γH2AX staining. Wee1 inhibition attenuated radiation-induced G2 arrest in the Hep3B (TP53 null) and Huh7 (TP53 mutant) cell lines but not in the TP53 wild-type cell line HepG2. Supplementation with nucleosides reversed the radiation-sensitizing effect of AZD1775 and reduced the amount of cells with pan-nuclear γH2AX staining after radiation.

CONCLUSIONS

Radiation sensitization with Wee1 inhibition occurs in cells regardless of their p53 mutational status. In this study we show for the first time that replication stress via the overconsumption of nucleotides plays an important role in AZD1775-induced radiation sensitization.

The role of cyclins and cyclin dependent kinases in development and progression of hepatitis C virus-genotype 4-associated hepatitis and hepatocellular carcinoma

Altered cell cycle regulatory genes expression contributes to HCV-associated liver disease. We sought to assess the role of cyclins and cyclin dependent kinases (CDKs) in HCV-associated CH and HCC. Aberrant expression of cyclins A, E, D1, CDK2 and CDK4 was assessed by immunohistochemistry and differential PCR in HCV-associated CH and HCC with pericarcinomatous foci (PCF). S phase fraction (SPF) was determined by flow cytometry. Results were correlated with overall survival (OS) in HCC patients. In HCC, cyclins A, E, D1, CDK2 and CDK4 protein overexpression was detected in 52.8%, 52.8%, 69%, 47% and 58% compared to 36.1%, 33%, 56%, 27.8%, 55.6% for CH and 36.1%, 27%, 30.6%, 27%, 50% for PCF. Gene amplification was detected in 38.9%, 33% 66%, 33%, 44% of HCC compared to 27.8%, 25%, 44%, 27.8%, 36% in CH and 25%, 22.2%, 38.9%, 27%, 33% in PCF. A significant difference was reported between HCC, CH, NHT regarding cyclins A, E, D1, CDK2 (p=0.007, p=0.002, p=0.047, p=0.002) protein expression (ADD) and cyclin D1 amplification (p=0.009). Cyclins A, E, CDK2 expression was associated with fibrosis in CH (p=0.004, p=0.02, p=0.012). Reduced OS was (ADD) associated with cyclin D1 and cyclin A, grade, stage and metastasis (p=0.001, p=0.02, p=0.018, p=0.01, p=0.001).

CONCLUSIONS

Increased cyclins A, E, D1, CDK2 and CDK4 expression is important for HCV-associated CH and HCC. Cyclin D1 and cyclin A are prognostic biomarkers associated with reduced OS in HCC. Cyclin D1 aberration could identify high risk groups of CH patients prone to develop HCC.

Hepatocellular carcinoma with a "nodule-in-nodule" appearance reflecting an unusual dilated pseudoglandular structure

We present a case of hepatocellular carcinoma (HCC), showing an atypical "nodule-in-nodule" appearance on ultrasonogram (US). In general, a "nodule-in-nodule" appearance is found as a hyperechoic tumor containing a hypoechoic nodule. In the present case, however, there was a hyperechoic subnodule in the center of the tumor, which was surrounded by a hypoechoic tumor area. Histologically, the subnodule consisted of moderately differentiated HCC with a markedly dilated pseudoglandular structure, and the outer tumor consisted of well-differentiated HCC with a thin-trabecular pattern. It should be noted that there is a rare HCC with dilated pseudoglandular structure showing the inversed "nodule-in-nodule" appearance.

Molecular mechanisms of liver carcinogenesis in the mdr2-knockout mice

Mouse models of hepatocellular carcinoma (HCC) simulate specific subgroups of human HCC. We investigated hepatocarcinogenesis in Mdr2-knockout (Mdr2-KO) mice, a model of inflammation-associated HCC, using gene expression profiling and immunohistochemical analyses. Gene expression profiling showed that although Mdr2-KO mice differ from other published murine HCC models, they share several important deregulated pathways and many coordinately differentially expressed genes with human HCC data sets. Analysis of genome positions of differentially expressed genes in liver tumors revealed a prolonged region of down-regulated genes on murine chromosome 8 in three of the six analyzed tumor samples. This region is syntenic to human chromosomal regions that are frequently deleted in human HCC and harbor multiple tumor suppressor genes. Real-time reverse transcription-PCR analysis of 16 tumor samples confirmed down-regulation of several tumor suppressors in most tumors. We show that in the aged Mdr2-KO mice, cyclin D1 nuclear level is increased in dysplastic hepatocytes that do not form nodules; however, it is decreased in most dysplastic nodules and in liver tumors. We found that this decrease is mostly at the protein, rather than the mRNA, level. These findings raise the question on the role of cyclin D1 at early stages of hepatocarcinogenesis in the Mdr2-KO HCC model. Furthermore, we show that most liver tumors in Mdr2-KO mice were characterized by the absence of beta-catenin activation. In conclusion, the Mdr2-KO mouse may serve as a model for beta-catenin-negative subgroup of human HCCs characterized by low nuclear cyclin D1 levels in tumor cells and by down-regulation of multiple tumor suppressor genes.

Hepatic expression of the proliferative marker Ki-67 and p53 protein in HBV or HCV cirrhosis in relation to dysplastic liver cell changes and hepatocellular carcinoma

To evaluate hepatic expression of the nuclear proliferative marker Ki-67 and the p53 oncoprotein in hepatitis B virus (HBV)/HCV cirrhosis in relation to dysplastic liver cell changes and hepatocellular carcinoma (HCC). We studied needle liver biopsies from 107 patients with cirrhosis and no HCC (52 HBV, 55 HCV) who had been assessed for protocol studies, and 57 cirrhotic patients with HCC (40 HBV, 17 HCV). We evaluated small and large cell dysplastic changes along with the expression of Ki-67 and p53 by immunohistochemistry. The labelling index (LI) was defined as the proportion (%) of positive-stained nuclei of the 500 measured. Large and small cell dysplastic changes were observed in 12 and 9% of specimens respectively. Only small cell changes were associated with Ki-67 expression. Ki-67 LI was 5.50 +/- 5.7 in cirrhosis (13.90 +/- 3.84 in those with small cell dysplastic changes vs 4.64 +/- 4.98 in those without, P < 0.01), 10.2 +/- 5.95 in cirrhosis with HCC (P < 0.05) and 18.56 +/- 10 in HCC (P < 0.01). Neither the presence of small cell dysplastic changes nor the expression of Ki-67 was related to severity or aetiology of cirrhosis. Expression of p53 was observed in 30% of the non-tumorous and in 53% of the neoplastic tissue obtained from patients with HCC, with no differences between HCV and HBV. Ki-67 and p53 expression was associated with the tumour grade (P < 0.001). Our observations clearly demonstrate the association between the proliferation activity and the morphological changes in the cirrhotic liver from the non-dysplastic to dysplastic lesion to HCC. They also support the hypothesis that p53 alterations are a rather late event in carcinogenesis and related to HCC grade. And finally, they suggest that the final steps of hepatocarcinogenesis are common and independent of the aetiology of the chronic viral infection.

Risk factors for hepatocellular carcinoma in Hepatitis C patients with sustained virologic response to interferon therapy

BACKGROUND

Although a variety of papers demonstrated inhibited hepatocarcinogenesis with interferon (IFN) therapy for chronic hepatitis C, a small number of hepatocellular carcinomas (HCCs) were still observed even in sustained virologic responders.

AIMS

To clarify factors affecting the development of HCC, we analyzed the frequency of HCC in sustained virologic responders over a long-term observation period.

METHODS

Seven hundred and ninety-two out of the 2623 IFN-treated hepatitis C patients who had undergone liver biopsy showed sustained virologic response. Screening for development of HCC was performed periodically during an average follow-up of 5.1 years. Fibrosis of the pretreatment liver biopsy sample was graded. Risk factors for HCC were analyzed by using Cox proportional hazards regression.

RESULTS

Of 792 patients, 23 developed HCC. Univariate analysis showed that stage of hepatic fibrosis, age, and alcohol consumption were significantly associated with a risk of HCC (P<0.001). There was a significant difference in the cumulative incidence between patients stratified according to these variables (P<0.001).

CONCLUSIONS

Pretreatment hepatic fibrosis score, age, and alcohol consumption may affect development of HCC even in sustained virologic responders. Thus, patients with these factors should be carefully followed even after eradication of the virus.

Reduced expression of cell cycle regulator p18(INK4C) in human hepatocellular carcinoma

Cyclins, cyclin-dependent kinases (Cdks), and Cdk inhibitors (CdkIs) are frequently altered in human cancer. p18INK4C, a member of the INK4 family of CdkIs, is a potential tumor-suppressor gene product. However, the expression of p18INK4C in hepatocellular carcinoma (HCC) remains unknown. The aim of this study was to examine the expression of p18INK4C in various liver diseases including HCC and to assess its clinical significance in HCC. To that end, we examined the expression of p18INK4C by immunohistochemistry in various liver diseases, including 51 HCCs, and also studied the relationship between p18INK4C expression, the phosphorylation of retinoblastoma protein (pRb), and the activity level of Cdk4 and Cdk6. Immunohistochemical analysis revealed the frequent loss of p18INK4C expression in HCC, especially in poorly differentiated HCC. The loss of p18INK4C expression was shown to be associated with a poor prognosis compared with that associated with p18INK4C- positivity. Further, the kinase activity of Cdk4 was found to be higher in p18INK4C-negative HCCs than in p18INK4C- positive HCCs. However, the level of Cdk6 activity was similar in the 2 groups of HCCs. In p18INK4C- positive HCCs, p18INK4C dominantly interacted with Cdk4 rather than with Cdk6. pRb phosphorylated at serine(Ser) 780 was detected more frequently in p18INK4C - negative than in p18INK4C - positive HCCs. In conclusion, the loss of p18INK4C expression may play a role in the differentiation and development of HCC through the up-regulation of Cdk4 activity.

Hepatocellular carcinomas <2 cm in diameter complicating cirrhosis: ultrasound and clinical features in 153 consecutive patients

PURPOSE

To determine the frequencies of various echogenicity patterns in 153 consecutive unifocal hepatocellular carcinomas (HCCs) <2 cm detected in cirrhotic livers and to identify their relationships with clinical, laboratory, and microscopic features.

PATIENTS AND METHODS

The tumors were classified as hypoechoic, hyperechoic, isoechoic, or nodule-in-nodule. Correlation was evaluated between hypoechoic and hyperechoic patterns and the following variables: age, gender, serum alphafetoprotein (AFP), tumor size, ultrasound features of liver parenchyma, cirrhosis etiology, and cyto/histological tumor grading.

RESULTS

One hundred and seventeen tumors (76.4%) were hypoechoic, 26 (17.0%) were hyperechoic, 5 (3.3%) were isoechoic, and 5 (3.3%) had nodule-in-nodule patterns. The hyperechoic pattern was more common in patients under 69 years (25.0% vs. 11.3% in those under 69 years or older, P=0.033). Patients with a hyperechoic pattern displayed a trend towards lower AFP levels and higher prevalence of hepatitis C-related cirrhosis. The prevalence of well-differentiated tumors was identical (56.6% and 56.5%) in the hypoechoic and hyperechoic subgroups. AFP was higher than 400 ng/ml in only 11/153 cases (7.2%).

CONCLUSIONS

The hyperechoic pattern of HCC is by no means uncommon, particularly in patients under 70. Hyperechogenicity is not related to an increased frequency of well-differentiated tumors. AFP shows limited value as a confirmatory test of small HCC.

Cyclins and cyclin-dependent kinases: comparative study of hepatocellular carcinoma versus cirrhosis

Increasing evidence has indicated that perturbation of cyclins is one of the major factors leading to cancer. The aim of this study was not only to investigate various cell cycle-related kinase activities in hepatocellular carcinoma (HCC), but also to analyze the difference of cell cycle-related kinase activity levels between hepatitis C virus (HCV)-induced HCC and HCV-induced cirrhosis. The protein levels of cyclins D1, E, A, and H, and of cyclin dependent kinase 1 (Cdk1), Cdk2, Cdk4, Cdk6, and Cdk7 in HCC and in surrounding nontumorous cirrhosis were determined by Western blot. The enzymatic activities of cyclins D1, E, A, Cdk1, Cdk4, Cdk6, Cdk7, and Wee1 were measured using in vitro kinase assays. Protein levels and kinase activities of cyclin D1, Cdk4, cyclin E, cyclin A, and Wee1 were significantly elevated in HCC compared with surrounding cirrhotic tissues. The enhanced cyclin D1-related kinase activity in HCC was accompanied by the up-regulation of Cdk4 activity, but not Cdk6 activity. The kinase activities of Cdk6, Cdk7, and Cdk1 did not differ between HCC and surrounding cirrhotic tissues. In addition, the protein levels and kinase activities of cyclin D1, Cdk4, and cyclin E were higher in poorly differentiated HCC and advanced HCC. In conclusion, the increases of cyclin D1, Cdk4, cyclin E, cyclin A, and Wee1 play an important role in the development of HCC from cirrhosis. Cyclin D1, Cdk4, and cyclin E activation may be closely related to the histopathologic grade and progression of HCC.

Hepatocellular carcinoma with an unusual medullary-like histology and signs of regression ("medullary-like hepatocellular carcinoma")

The case of a variant of hepatocellular carcinoma is described, which, based on its unique histology, we propose to term, medullary-like hepatocellular carcinoma. It developed in a 56-year-old male patient with liver cirrhosis, and consisted of large, amphophilic cells with a solid growth pattern. The tumour was densely infiltrated with lymphocytes and plasma cells. Lymphocytes formed a mixture of B and T cells, and plasma cells were polytypic. In addition, numerous S-100 protein-reactive stellate cells were observed at the tumour border, where marked apoptosis of hepatocellular carcinoma cells was evident. In areas of dense lymphoplasmacytic infiltration, part of the tumour cells had lost their intercellular connections and their beta-catenin reactivity. Some tumour cells expressed FasL, but not Fas. The tumour exhibited several foci of regression, showing small remnants of damaged tumour cells within dense infiltrations. The patient is alive without evidence of disease 25 months after resection. Medullary-like hepatocellular carcinoma is a lesion which mimics several features known for other medullary carcinomas, including a marked immune response which may be responsible for partial regression of this tumour.

Activation of hepatic stellate cells in liver tissue of patients with fulminant liver failure after treatment with bioartificial liver

We studied the explanted livers from 12 patients with fulminant hepatic failure who were treated with a bioartificial liver and subsequently underwent orthotopic liver transplantation and from 18 patients who underwent orthotopic liver transplantation without previous treatment. Ten normal livers were used as controls. In addition to morphologic evaluation, an immunohistochemical analysis was performed with the monoclonal antibodies for alpha-smooth muscle actin and proliferation marker Ki-67. The expression of these markers was graded semiquantitatively from 0 to 3+ in a blinded fashion. The zonal distribution of activated hepatic stellate cells was also evaluated. In all cases, the hepatic stellate cells were activated and expressed alpha-smooth muscle actin. In all patients with submassive or massive liver cell necrosis, the distribution of activated hepatic stellate cells was predominantly in zone 1 of the acinus (periportal area). In contrast, in cases with early nodular regeneration and no significant fibrosis, the activated hepatic stellate cells were distributed throughout the liver parenchyma, involving zones 2 and 3 of the acinus. Expression of the proliferation marker Ki-67 was graded 3+ in all patients treated with the bioartificial liver who had orthotopic liver transplantation and 2+ in patients who underwent orthotopic liver transplantation only.