Expression of proliferation associated antigens and detection of numerical chromosome aberrations in primary human liver tumours: relevance to tumour characteristics and prognosis

Ancillary tests for hepatobiliary neoplasms: what we know and what we need to know

Ancillary tests are commonly used in the surgical pathology setting for diagnosing challenging neoplastic diseases of the liver and biliary tract, while histology and clinical correlation remain to be critically important. With continuous discoveries, more and more useful ancillary tests have become available, which can help distinguish between malignant and benign hepatocellular neoplasms, malignant and benign biliary tract entities, and intrahepatic and metastatic carcinomas. This review will focus on existing and emerging biomarkers (such as glutamine synthetase, organic anion transporting polypeptide 1B3, insulin-like growth factor-II mRNA binding protein-3, S100P, SMAD4, enhancer of zeste homolog 2, albumin, hepatocyte nuclear factor-1β, etc.) that can be used for the diagnosis, classification and prognostication of hepatobiliary neoplasms.

Senescence markers in focal nodular hyperplasia of the liver: pathogenic considerations on the basis of immunohistochemical results

Focal nodular hyperplasia (FNH) is a polyclonal tumour-like hepatic lesion characterised by parenchymal nodules, connective tissue septa without interlobular bile ducts, pronounced ductular reaction and inflammation. It may represent a response to local arterial hyperperfusion and hyperoxygenation resulting in oxidative stress. We aimed at obtaining closer insight into the pathogenesis of FNH with its characteristic morphologic features. Immunohistochemistry and immunofluorescence microscopy was performed on FNH specimens using antibodies against keratins (K) 7 and 19, neural cell adhesion molecule (NCAM), lamin B1, senescence markers (CDK inhibitor 1/p21^Cip1, CDK inhibitor /p16^Ink4a, senescence-associated (SA) β- galactosidase activity), proliferation markers (Ki-67, proliferating-cell nuclear antigen (PCNA)), and the abnormally phosphorylated histone γ-H2AX, indicating DNA double strand breaks; moreover SA β- galactosidase activity was determined histochemically. Ductular metaplasia of hepatocytes indicated by K7 expression in the absence of K19 plays a major role in the development of ductular reaction in FNH. Moreover, the expression of senescence markers (p21^Cip1, p16^Ink4a, γ-H2AX, SA β-galactosidase activity) in hepatocytes and cholangiocytes suggests that stress-induced cellular senescence contributes to fibrosis and inflammation via production of components of the senescence-associated secretory phenotype. Expression of proliferation markers (Ki-67, PCNA) was not enhanced in hepatocytes and biliary cells. Senescence and ductular metaplasia of hepatocytes may thus be involved in inflammation, fibrosis and apoptosis resistance. Hence, fibrosis, inflammation and reduced apoptotic cell death, rather than proliferation (hyperplasia) may be responsible for increased tissue mass and tumour-like appearance of FNH.

Clinicopathological and prognostic significance of high Ki-67 labeling index in hepatocellular carcinoma patients: a meta-analysis

BACKGROUND

The relationship between Ki-67 labeling index (LI) and clinical outcome in hepatocellular carcinoma (HCC) has been investigated by various studies, but no consistent result has been concluded. To define the prognostic significance of Ki-67 LI in patients with HCC, we performed a meta-analysis.

METHODS

We searched for literatures in the following databases: PubMed, ISI Web of Science, EMBASE, Cochrane Central Register of Controlled Trials, Science Direct, Wiley Online Library, Google Scholar, China National Knowledge Infrastructure (CNKI), Chinese VIP and WanFang Databases. Our search ended on April 6th, 2015. Data were extracted from eligible studies and the correlation between Ki-67 LI and clinicopathological features of HCC was analyzed and pooled hazard ratios (HRs) for eligible studies were calculated by STATA 11.0 (STATA Corp., College, TX).

RESULTS

In total, 54 studies involving 4996 patients were included in the current meta-analysis. The meta-analysis provided evidence that high Ki-67 LI was closely associated with histological grade, tumor size, number of tumor nodes, the status of metastasis, cirrhosis and vein invasion in HCC patients. The pooled HRs showed that high Ki-67 LI had an unfavorable impact on disease-free survival (DFS) (HR=1.626, 95% confidence interval (CI): 1.364-1.939, P<0.001), relapse-free survival (RFS) (HR=1.820, 95% CI: 1.215-2.725, P=0.004) and overall survival (OS) (HR=1.170, 95% CI: 1.102-1.243, P<0.001), respectively. Additionally, subgroup analysis indicated that high Ki-67 LI was related to poorer DFS, RFS and OS independent of regions, treatment strategies or statistical methods, except that no statistical significance was found on RFS (HR=2.413, 95% CI: 0.523-11.142, P=0.259) and OS (HR=1.998, 95% CI: 0.797-5.009, P=0.14) in patients with liver transplantation.

CONCLUSIONS

Our meta-analysis suggests that higher Ki-67 LI confers a fast progression and poor prognosis for HCC patients.

Selective targeting of genetically engineered mesenchymal stem cells to tumor stroma microenvironments using tissue-specific suicide gene expression suppresses growth of hepatocellular carcinoma

BACKGROUND

The use of engineered mesenchymal stem cells (MSCs) as therapeutic vehicles for the treatment of experimental pancreatic and breast cancer has been previously demonstrated. The potential application of MSCs for the treatment of hepatocellular carcinoma (HCC) has been controversial. The general approach uses engineered MSCs to target different aspects of tumor biology, including angiogenesis or the fibroblast-like stromal compartment, through the use of tissue-specific expression of therapeutic transgenes. The aim of the present study was (1) to evaluate the effect of exogenously added MSCs on the growth of HCC and (2) the establishment of an MSC-based suicide gene therapy for experimental HCC.

METHODS

Mesenchymal stem cells were isolated from bone marrow of C57/Bl6 p53(-/-) mice. The cells were injected into mice with HCC xenografts and the effect on tumor proliferation and angiogenesis was evaluated. The cells were then stably transfected with red fluorescent protein (RFP) or Herpes simplex virus thymidine kinase (HSV-Tk) gene under control of the Tie2 promoter/enhancer or the CCL5 promoter. Mesenchymal stem cells were injected intravenously into mice with orthotopically growing xenografts of HCC and treated with ganciclovir (GCV).

RESULTS

Ex vivo examination of hepatic tumors revealed tumor-specific recruitment, enhanced tumor growth, and increased microvessel density after nontherapeutic MSC injections. After their homing to the hepatic xenografts, engineered MSCs demonstrated activation of the Tie2 or CCL5 promoter as shown by RFP expression. Application of CCL5/HSV-TK transfected MSCs in combination with GCV significantly reduced tumor growth by 56.4% as compared with the control group and by 71.6% as compared with nontherapeutic MSC injections. CCL5/HSV-TK(+) transfected MSCs proved more potent in tumor inhibition as compared with Tie2/HSV-TK(+) MSCs.

CONCLUSION

Exogenously added MSCs are recruited to growing HCC xenografts with concomitant activation of the CCL5 or Tie2 promoters within the MSCs. Stem cell-mediated introduction of suicide genes into the tumor followed by prodrug administration was effective for treatment of experimental HCC and thus may help fill the existing gap in bridging therapies for patients suffering from advanced HCCs.

Diagnosis of well-differentiated hepatocellular lesions: role of immunohistochemistry and other ancillary techniques

There is considerable overlap in morphologic features in well-differentiated hepatocellular lesions necessitating the use of immunohistochemistry and other techniques for diagnosis. Map-like pattern with glutamine synthetase in focal nodular hyperplasia and cytoplasmic staining with serum amyloid associated protein in inflammatory hepatocellular adenoma (HA) are useful for this distinction. The distinction of well-differentiated hepatocellular carcinoma (HCC) and HA in noncirrhotic liver is facilitated by demonstrating glypican-3 and cytogenetic changes like gains of chromosomes 1 and 8. Nuclear staining with β-catenin and/or diffuse staining with glutamine synthetase strongly favors well-differentiated HCC or HA with high risk for HCC. In a cirrhotic liver, separation of early HCC from high-grade dysplastic nodule requires identification of stromal invasion, which can be highlighted by absence of keratin 7-positive ductular reaction. Combined use of heat shock protein 70, glutamine synthetase, and glypican-3 can be useful as positivity for 2 or more of these markers has shown high specificity for HCC in early studies.

Integration of in vivo genotoxicity and short-term carcinogenicity assays using F344 gpt delta transgenic rats: in vivo mutagenicity of 2,4-diaminotoluene and 2,6-diaminotoluene structural isomers

An important trend in current toxicology is the replacement, reduction, and refinement of the use of experimental animals (the 3R principle). We propose a model in which in vivo genotoxicity and short-term carcinogenicity assays are integrated with F344 gpt delta transgenic rats. Using this model, the genotoxicity of chemicals can be identified in target organs using a shuttle vector λ EG10 that carries reporter genes for mutations; short-term carcinogenicity is determined by the formation of glutathione S-transferase placenta form (GST-P) foci in the liver. To begin validating this system, we examined the genotoxicity and hepatotoxicity of structural isomers of 2,4-diaminotoluene (2,4-DAT) and 2,6-diaminotoluene (2,6-DAT). Although both compounds are genotoxic in the Ames/Salmonella assay, only 2,4-DAT induces tumors in rat livers. Male F344 gpt delta rats were fed diet containing 2,4-DAT at doses of 125, 250, or 500 ppm for 13 weeks or 2,6-DAT at a dose of 500 ppm for the same period. The mutation frequencies of base substitutions, mainly at G:C base pairs, were significantly increased in the livers of 2,4-DAT–treated rats at all three doses. In contrast, virtually no induction of genotoxicity was identified in the kidneys of 2,4-DAT–treated rats or in the livers of 2,6-DAT–treated rats. GST-P–positive foci were detected in the livers of rats treated with 2,4-DAT at a dose of 500 ppm but not in those treated with 2,6-DAT. Integrated genotoxicity and short-term carcinogenicity assays may be useful for early identifying genotoxic and nongenotoxic carcinogens in a reduced number of experimental animals.

Pelioid hepatocellular carcinoma in an adult Eurasian badger (Meles meles)

A mass was identified within the left lateral lobe of the liver of a 10-year-old Eurasian badger (Meles meles). The mass was friable and multilobulated, with blood-filled spaces between the lobules. Microscopically, the lesion consisted of sheets and trabeculae of neoplastic hepatocytes often forming cystic spaces containing erythrocytes, fibrin and necrotic debris. The histological appearance was consistent with hepatocellular carcinoma (HCC). Immunohistochemically, the neoplastic cells expressed cytokeratin 18 but not von Willebrand factor. Multiple intranuclear (amphophilic or acidophilic) inclusion bodies were observed in hepatocytes at the junction between the tumour and normal hepatic tissue. HCCs have also been reported in other domestic and wild animals. As hepadnavirus infection has been associated with HCC in woodchucks, further histochemical and transmission electron microscopical studies were performed; however, these demonstrated that the inclusions consisted of lipid droplets and not viral particles. To our knowledge, this is the first report of a naturally occurring HCC in a Eurasian badger.

A case of hepatocellular carcinoma within hepatocellular adenoma in a non-cirrhotic male

Hepatocellular adenoma (HA) is a benign hepatic lesion that predominantly occurs in young women. Most hepatocellular carcinomas (HCC) arise in a cirrhotic liver during the fifth or sixth decades. There have been several reported cases of HCC developing from HA in female patients. However, there are rare cases about HCC arising in HA in a non-cirrhotic male patient. We have recently encountered a 53-year-old man who had a liver mass in a non-cirrhotic liver, and the liver mass was compatible with HA on the pre-operative computed tomography. The mass was completely resected and the histopathology revealed a focus of HCC arising in HA. We report here on this case along with a brief review of the relevant literature.

Histopathologic and immunohistochemical features of tissue adherent to multitined electrodes after RF ablation of liver malignancies can help predict local tumor progression: initial results

PURPOSE

To determine whether histopathologic and immunohistochemical features of tissue adherent to electrodes after radiofrequency (RF) ablation of liver malignancies can help predict local tumor progression (LTP).

MATERIALS AND METHODS

Institutional review board waiver and informed consent were obtained. Histologic and immunohistochemical examinations of tissue adherent to electrodes after RF ablation of liver malignancies were performed, with application of proliferation (Ki-67) and apoptosis (caspase-3) markers. Clinical and technical information were prospectively collected for an HIPAA-registered database. Medical records and imaging were reviewed to determine LTP for treated tumors smaller than 5 cm in diameter. LTP-free and survival rates were assessed with Kaplan-Meier method; differences between groups assessed with permutation log-rank test. Multivariate analysis assessed with Cox regression for factors related to LTP.

RESULTS

Sixty-eight malignant tumors treated with RF ablation were identified. Fifty-five tissue specimens were classified as coagulation necrosis (CN), thermal artifact only, or tumor cells positive for caspase-3/negative for Ki-67; and 13 as viable tumor cells (Ki-67 positive). Mean tumor size was larger in viable (3.4 cm) than in CN (2.5 cm) group before treatment (P = .01). For viable and CN groups, LTP occurred in 12 (92%) of 13 and 16 (29%) of 55 specimens, respectively; 1-year LTP-free rates were 0% and 74%, respectively (P < .001). Multivariate analysis confirmed that viable cells comprise independent risk factor for LTP (P < .001). The odds of LTP is six times greater in viable group compared with CN group for tumors 3-5 cm (hazard ratio: 5.9, 95% confidence interval: 2.4, 14.5) and 10 times greater for tumors smaller than 3 cm (hazard ratio: 10.1, 95% confidence interval: 1.7, 57.5). Median survival was 32.7 months.

CONCLUSION

Evidence of Ki-67-positive tumor cells on the electrode after hepatic RF ablation is an independent predictor of LTP.

Laminin-5 stimulates hepatocellular carcinoma growth through a different function of alpha6beta4 and alpha3beta1 integrins

Hepatocellular carcinoma (HCC) growth severely affects prognosis. Ki-67, a known marker of cell proliferation, is a negative prognostic factor in HCC. Growth factors such as the epidermal growth factor (EGF) induce HCC cell proliferation but do not explain the great heterogeneity of HCC growth. Laminin-5 (Ln-5) is an extracellular matrix protein (ECM) present in the tissue microenvironment of HCC. The two main receptors for Ln-5, integrins alpha3beta1 and alpha6beta4, are expressed on the cell surface of HCC cells. The aim of this study is to investigate an alternative mechanism of HCC growth whereby Ln-5 promotes HCC cell proliferation through alpha3beta1 and alpha6beta4. HCC tissues containing Ln-5 display a larger diameter and higher number of positive cells for Ki-67, a well known proliferative index, as determined by double immunofluorescence staining and real-time PCR on microdissected tissues. In vitro, Ln-5, but not collagen I, collagen IV or fibronectin, induces proliferation as much as EGF does, via Erk phosphorylation as a consequence of beta4 integrin phosphorylation. However, the two HCC cell lines do not proliferate in presence of Ln-5 despite beta4 integrin and Erk1/2 activation. After transfection with alpha3 integrin, in the presence of Ln-5 one of these HCC cell lines acquires a proliferative activity whereas one of the proliferative HCC cell lines, knocked-down for alpha3 integrin, loses its proliferative activity.

CONCLUSIONS

Our study suggests a new mechanism of HCC growth whereby Ln-5 stimulates proliferation via a different function of alpha6beta4 and alpha3beta1.

Isolation and comparative characterization of Ki-67 equivalent antibodies from the HuCAL phage display library

It has been shown that a repetitive motif with the sequence FKEL(F) within the Ki-67 antigen (pKi-67) serves as an epitope for the Ki-67 antibody and equivalent clones. However, no direct correlation between reactivity towards Ki-67 epitopes and reactivity in formalin-fixed paraffin-embedded (FFPE) tissue could be found. In this study our aim was the isolation and characterization of new monoclonal Ki-67 equivalent antibodies in an in vitro approach. To select pKi-67 reactive phage antibodies, we used a large naive Fab-phage library (Human Combinatorial Antibody Library; HuCAL). We implemented a panning strategy against two different overlapping peptides, both containing the 'FKELF' epitope. ELISA screening of randomly picked phage antibody clones after the third selection round yielded six highly reactive clones against the 'FKELF' epitope, of which five were found to be reactive in FFPE tissue, showing a Ki-67 equivalent staining pattern. Substitutional epitope analysis on peptide arrays of the new recombinant pKi-67 binders and of the established murine clones Ki-67, Mib-1 and Mib-5 were carried out to compare their fine specificities. The results suggest that the lysine residue in the epitope is critical for recognition of Ki-67 antigen in FFPE tissue.

Identification of a unique gene expression signature that differentiates hepatocellular adenoma from well-differentiated hepatocellular carcinoma

It is often difficult to distinguish hepatocellular adenoma (HCA) from well-differentiated hepatocellular carcinoma (WDHCC) when limited tissue from a needle biopsy is evaluated. The aim of this study was to identify gene expression patterns that can distinguish HCA from WDHCC, with the ultimate goal of discovering novel diagnostic markers. Gene expression profile analysis was performed using Affymetrix U133Plus2 GeneChip microarrays on RNA isolated from frozen tissue of 6 HCA and 8 WDHCC specimens. Statistical analysis of microarray data identified 63 genes whose expression levels were significantly different between HCA and WDHCC. These included 57 genes overexpressed by HCA and 6 overexpressed by WDHCC. Eight genes were chosen for further analysis by quantitative RT-PCR on RNA derived from archived, paraffin-embedded tissue blocks of an independent validation set comprising 9 HCAs and 9 HCCs. Seven of the 8 genes demonstrated average expression differences between HCA and HCC that were concordant with the microarray findings, and their expression pattern correctly classified the 18 tumors into HCA and HCC using unsupervised clustering analysis. Furthermore, immunohistochemical staining performed on a third, independent set of 27 HCAs and 33 HCCs confirmed the expression differences at protein levels for 5 of the genes. Taken together, our data demonstrate significant molecular differences between HCA and WDHCC, despite their morphologic similarity. More importantly, we have identified a unique set of genes whose expression pattern can discriminate between these two types of hepatocellular neoplasms, suggesting the possibility of future development of ancillary molecular and immunohistochemical diagnostic methods.

Immunohistochemical and molecular markers in the diagnosis of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has distinct morphologic features and can be identified in the majority of cases by routine hematoxylin and eosin (H&E)-stained formalin-fixed paraffin-embedded sections. However, distinguishing a well-differentiated HCC from normal or regenerative tissue may be very difficult in some cases, particularly in small needle aspiration or core biopsies. Furthermore, some of the unusual morphologic variants, including clear-cell, pleomorphic, and sarcomatoid variants, may be mistaken for metastases. Similarly, metastases from various primary tumors to the liver may be mistaken for primary hepatic tumors. In this overview, we summarize the immunohistochemical and molecular markers that have been developed to address these diagnostic challenges. Among the numerous diagnostic markers studied, pCEA, HepPar 1, CD34, CK 7, CK 19, CK 20, and albumin in situ (ISH) have been found to be valuable in distinguishing HCC from metastatic neoplasms of extrahepatic sites.

Expression of MIB-1 and bcl-2 in hepatocellular carcinoma and paracarcinomatous tissues

AIM: To investigate the effects of MIB-1 and bcl-2 proteins expression in the primary hepatocellular carcinoma(HCC) and their paracarcinomatous tissues.

METHODS: The expression of MIB-1 and bcl-2 proteins was evaluated in paraffin-embedded tissue by immunohistochemical techniques (S-P) in 40 cases of hepatocellular carcinoma.

RESULTS: The positive expression of MIB-1 was located in nucleus. The mean MIB-1 positive rate in HCCs was 27.61±13.26%, while MIB-1 positive cells in paracarcinomatous tissues were 1.24±1.67% (P < 0.001). The expression of MIB-1 in HCCs was related to the cancer grading, the lower the differentiation of HCCs, the higher the MIB-1 proliferation index (P < 0.01). As for the paracarcinomatous tissues the MIB-1 proliferation index of small liver cell dysplasia (LCD) was higher than that of its adjacent liver tissue. However, in larger cell LCD, the MIB-1 index had no significant difference compared with that of its adjacent tissue. The positive rates of bcl-2 in cancer and paracarcinomatous tissues were 17.5% (7/40) and 77.5% (31/40) respectively. The bcl-2 expression was located in cytoplasm and its positive signals were strong and cluster-like in paracarcinomatous tissues, while the number of the bcl-2 positive cell was sporadic and the signals were weak and "piece-meal like" in HCCs.

CONCLUSION: This study shows that the MIB-1 proliferation index reflects the proliferation speed and the degree of anaplasia in HCCs. The higher expression of MIB-1 in small cell LCD suggests that its proliferation is faster than that of large cell LCD and their adjacent liver tissues, so the small cell LCD is more approximate to HCCs. The study also shows that bcl-2 may not directly play a role in liver cell proliferation during the processes of liver cell carcinogenesis, but it may take part in liver cell apoptosis regulated by the reduction of bcl-2 protein level.

Liver cell adenoma with malignant transformation: A case report

A 57-year-old woman was referred to our hospital because of a liver mass detected by computed tomography. She had taken oral contraceptives for only one month at the age of thirty. Physical examination revealed no abnormalities, and laboratory data, including hepatic function tests, were within the normal range, with the exception of elevated levels of those serum proteins induced by the absence of vitamin K or by raised levels of the antagonist (PIVKA)-II (3502 AU/mL). Abdominal ultrasonography revealed a hyperechoic mass measuring 10 × 10 cm in the left posterior segment of the liver. Because hepatocellular carcinoma could not be completely excluded, this mass was resected. The tumor consisted of sheets of uniform cells with clear cytoplasm, perinuclear eosinophilic granules and round nuclei. These histological findings were consistent with liver cell adenoma. Background hepatic tissue appeared normal. After resection of the tumor, serum PIVKA-II fell to within the normal range. An area of hepatocellular carcinoma (HCC) with a mid-trabecular pattern was immunohistochemically found, which was positive for PIVKA-II. Sinusoidal endothelial cells were CD34-positive, containing scattered PIVKA-II positive cells. This tumor was therefore finally diagnosed as liver cell adenoma with focal malignant transformation to HCC.

Cellular retinol-binding protein-1 in hepatocellular carcinoma correlates with beta-catenin, Ki-67 index, and patient survival

The cellular retinol-binding protein-1 (CRBP-1) plays a key role in the esterification and intercellular transfer of retinol. By in situ hybridization, immunohistochemistry, and confocal laser scanning microscopy (CLSM), we show that, in normal liver, CRBP-1 is strongly expressed in the cytoplasm of hepatic stellate cells (HSCs) and myofibroblasts (MFs) with only low CRBP-1 levels in hepatocytes. By contrast, in 196 hepatocellular carcinoma (HCC) specimens CRBP-1 expression in MFs was down-regulated in 83%. Patients with high CRBP-1 expression in MFs had a significantly higher 2-year survival as compared with patients with low CRBP-1 expression (52% vs. 29%, respectively; P =.034). An aberrant nuclear CRBP-1 accumulation resulting from cytoplasmic invagination was found in 29% of HCCs. Nuclear CRBP-1 staining correlated positively with a favorable tumor stage (Okuda stage I; P =.01) and negatively with the Ki-67(+) proliferation fraction (PF). A Ki-67(+) PF of > or =10% was associated with a lower 2-year survival probability as compared with patients with a Ki-67(+) PF of <10% (12% vs. 40%, respectively; P =.015). Prognosis did not correlate with the nuclear beta-catenin expression. There was, however, a close correlation between nuclear CRBP-1 inclusions and nuclear beta-catenin staining in HCCs (P =.008), suggesting a cross talk between CRBP-1 and the Wnt/wingless signal transduction pathway. In conclusion, our findings demonstrate that CRBP-1 detection may be useful for the discrimination between nonneoplastic and neoplastic liver cells and suggest that modulation of CRBP-1 expression in HCCs contributes to tumor growth and progression via retinoid-mediated signaling and disruption of cellular vitamin A homeostasis.

Proliferation of antigen MIB-1 in metastatic carcinoid tumours removed at liver transplantation: relevance to prognosis

BACKGROUND

Metastatic carcinoid tumours are difficult to manage. In spite of a multidisciplinary approach, including orthotopic liver transplantation, the recurrence rate is high with a poor prognosis. Histopathology generally fails to provide prognostic information, hence it is essential to try to identify markers of prognosis in these tumours before considering orthotopic liver transplantation. The MIB-1 antibody, which detects cell proliferative activity, has been shown to be a useful prognostic marker for a variety of neoplasms.

AIMS

To assess the value of MIB-1 immunostaining as a prognostic marker of the duration to recurrence and the survival of patients undergoing orthotopic liver transplantation for metastatic carcinoid/neuroendocrine tumours of the liver.

METHODS

Fourteen patients were included in the study. Formalin-fixed, paraffin-embedded tissue sections of the tumours were stained with routine haematoxylin and eosin and chromogranin. The cell proliferative activity was assessed by MIB-1 antibody labelling using the immunoperoxidase method. Results were correlated with the time of tumour recurrence and the length of patients' survival after transplantation.

RESULTS

No correlation was found between MIB-1 labelling index and age, gender, clinical and histological type of tumour (i.e. carcinoid, APUDOMA, secreting or non-secreting). The patients with higher MIB-1 indices ( 5%) showed a trend toward earlier recurrence and poorer survival than those with low MIB-1 indices ( 5%). The predictive value of a MIB-1 index of 2 indicating patient survival of 24 months was 83% (five out of six patients).

CONCLUSIONS

The correlation between MIB-1 index and patients' survival suggests that a high proliferative rate, as assessed by MIB-1 immunostaining, may detect those tumours with more aggressive biological behaviour. Prospective studies on a larger number of patients will be needed to determine if, in any individual tumour, this method will provide an additional parameter for a rational approach to therapy.

Evaluation of acute hepatotoxic effects exerted by environmental estrogens nonylphenol and 4-octylphenol in immature male rats

Nonylphenol (NP) and 4-Octylphenol (4OP) have shown estrogenic properties both in vivo and in vitro. Researchers have known for years that estrogens induce a wide number of hepatotoxic actions in rodents. In order to study the acute hepatic effects exerted by NP and 4OP on rat liver the following endpoints were evaluated: relative liver weight (RLW), morphology, cell cycle and ploidy status, monooxygenase enzymes content and levels of both, cytosolic estrogen receptor (cER) and microsomal binding sites for estrogens (mEBS). Immature male Sprague-Dawley rats were injected intraperitoneally (i.p.) with 60 mg/kg of NP or 4OP for 1, 5 or 10 days. Despite the fact that RLW of the animals was not modified but any treatment, the histopathological study revealed the presence of an increase in the percentage of both, mitotic activity and Ki-67-labeling index (LI) in the livers from animals treated with alkylphenols in absence of any degenerative lesion. Furthermore, all the livers from alkylphenols-treated groups showed the presence of abnormal mitosis and c-mitosis. Although the levels of both, cER and cytochrome P450 (Cyt. P450) were not affected by any treatment, concentration of the mEBS was decreased after 10 days of treatment with alkylphenols. These findings taken together suggest that the exposition to alkylphenols induce cell proliferation and spindle disturbances and that these compounds are capable of modulating the expression of putative membrane receptors for estrogens.

The prognostic molecular markers in hepatocellular carcinoma

The prognosis of hepatocellular carcinoma (HCC) still remains dismal, although many advances in its clinical study have been made. It is important for tumor control to identify the factors that predispose patients to death. With new discoveries in cancer biology, the pathological and biological prognostic factors of HCC have been studied quite extensively. Analyzing molecular markers (biomarkers) with prognostic significance is a complementary method. A large number of molecular factors have been shown to associate with the invasiveness of HCC, and have potential prognostic significance. One important aspect is the analysis of molecular markers for the cellular malignancy phenotype. These include alterations in DNA ploidy, cellular proliferation markers (PCNA, Ki-67, Mcm2, MIB1, MIA, and CSE1L/CAS protein), nuclear morphology, the p53 gene and its related molecule MD M2, other cell cycle regulators (cyclin A, cyclin D, cyclin E, cdc2, p27, p73), oncogenes and their receptors (such as ras, c-myc, c-fms, HGF, c-met, and erb-B receptor family members), apoptosis related factors (Fas and FasL), as well as telomerase activity. Another important aspect is the analysis of molecular markers involved in the process of cancer invasion and metastasis. Adhesion molecules (E-cadherin, catenins, serum intercellular adhesion molecule-1, CD44 variants), proteinases involved in the degradation of extracellular matrix (MMP-2, MMP-9, uPA, uPAR, PAI), as well as other molecules have been regarded as biomarkers for the malignant phenotype of HCC, and are related to prognosis and therapeutic outcomes. Tumor angiogenesis is critical to both the growth and metastasis of cancers including HCC, and has drawn much attention in recent years. Many angiogenesis-related markers, such as vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), platelet-derived endothelial cell growth factor (PD-ECGF), thrombospondin (TSP), angiogenin, pleiotrophin, and endostatin (ES) levels, as well as intratumor microvessel density (MVD) have been evaluated and found to be of prognostic significance. Body fluid (particularly blood and urinary) testing for biomarkers is easily accessible and useful in clinical patients. The prognostic significance of circulating DNA in plasma or serum, and its genetic alterations in HCC are other important trends. More attention should be paid to these two areas in future. As the progress of the human genome project advances, so does a clearer understanding of tumor biology, and more and more new prognostic markers with high sensitivity and specificity will be found and used in clinical assays. However, the combination of some items, i.e., the pathological features and some biomarkers mentioned above, seems to be more practical for now.

Activation of cyclin-dependent kinases CDC2 and CDK2 in hepatocellular carcinoma

BACKGROUND

The cyclin-dependent kinases (CDKs) CDC2 and CDK2 are key regulators of the cell cycle. The expression of the CDK alone does not necessary reflect their true activities because they are highly regulated by post-translational mechanisms. Human hepatocellular carcinoma (HCC) is one of the most common cancers in the world, but the kinase activities of CDKs in HCC have not been examined.

METHODS

Here we examined the protein expression and kinase activities associated with CDC2 and CDK2 in HCC and the corresponding non-tumorous liver tissues.

RESULTS

CDC2 and CDK2 are activated in HCC in over 70% and 80% of the cases, respectively, but have little correlation with clinical parameters and PCNA expression. Interestingly, PCNA was readily detectable in extracts from non-tumorous liver, but more than 60% of samples contain higher concentration of PCNA in HCC than the corresponding non-tumorous tissues. CDC2 and CDK2 are generally activated in the same HCC samples, but the extent of their activation varied significantly, suggesting that the pathways leading to the activation of CDC2 and CDK2 can be regulated independently. Both positive regulators of CDK activity like cyclins and CDKs, and negative regulators of CDK activity like p21(CIP1/WAF1) and Thr14/Tyr15 phosphorylation were up-regulated in HCC.

CONCLUSION

CDC2 and CDK2 are activated in HCC, and this may be due to a complex interplay between the level of the cyclin, CDK, CDK inhibitors, and inhibitory phosphorylation.

Hepatocellular carcinomas in native livers from patients treated with orthotopic liver transplantation: biologic and therapeutic implications

The gross and histopathologic characteristics of 212 nonfibrolamellar hepatocellular carcinomas (HCCs) discovered in native livers removed at the time of liver transplantation were correlated with features of invasive growth and tumor-free survival. The results show that most HCCs begin as small well-differentiated tumors that have an increased proliferation rate and induce neovascularization, compared with the surrounding liver. But at this stage, they maintain a near-normal apoptosis/mitosis ratio and uncommonly show vascular invasion. As tumors enlarge, foci of dedifferentiation appear within the neoplastic nodules, which have a higher proliferation rate and show more pleomorphism than surrounding better-differentiated areas. Vascular invasion, which is the strongest predictor of disease recurrence, correlates significantly with tumor number and size, tumor giant cells and necrosis, the predominant and worst degree of differentiation, and the apoptosis/mitosis ratio. In the absence of macroscopic or large vessel invasion, largest tumor size (P <.006), apoptosis/mitosis ratio (P <.03), and number of tumors (P <.04) were independent predictors of tumor-free survival and none of 24 patients with tumors having an apoptosis/mitosis ratio greater than 7.2 had recurrence. A minority of HCCs (<15%) quickly develop aggressive features (moderate or poor differentiation, low apoptosis/mitosis ratio, and vascular invasion) while still small, similar to flat carcinomas of the bladder and colon. In conclusion, hepatic carcinogenesis in humans is a multistep and multifocal process. As in experimental animal studies, aggressive biologic behavior (vascular invasion and recurrence) correlates significantly with profound alterations in the apoptosis/mitosis ratio and with architectural and cytologic alterations that suggest a progressive accumulation of multiple genetic abnormalities.

Benign tumors of the liver

Benign tumors of the liver, less commonly encountered than metastatic or primary liver tumors, may present clinically with symptoms due to mass effect, or may be discovered incidentally during radiographic evaluation or surgical exploration for other clinical indications. Many of the lesions that result in a benign liver mass are true neoplasms, while others result from reactive proliferation of hepatocytes, biliary cells, mesenchymal or inflammatory cells. The premalignant nature or potential for malignant transformation is of concern in some of the benign tumors or tumor-like masses of the liver. In this article, benign tumors and tumor-like masses involving the adult liver are discussed with a focus on histopathology, histogenesis, and clinical significance of these interesting and unusual lesions.

Both cell proliferation and apoptosis significantly predict shortened disease-free survival in hepatocellular carcinoma

In this study, we investigated the proliferating cell index by the percentage of Ki-67 expressing cells (Ki-67 LI) and the apoptotic index (AI) by the number of morphologically apoptotic cells per 1000 carcinoma cells in haematoxylin and eosin sections of 76 hepatocellular carcinomas (HCC). Both indices showed excellent correlation with each other (P < 0.0001) and were significantly higher in cases of poor differentiation, of advanced stages, with portal invasion and with intrahepatic metastasis. Furthermore, cases with higher Ki-67 LI or higher AI displayed poor outcomes for disease-free survival (P = 0.0001 and P = 0.0005) by univariate analysis. By multivariate analysis, both indices could be regarded as independent prognostic factors. These results strongly suggest that Ki-67 LI and AI have very similar clinical significance, reflecting the existence of biologically aggressive phenotypes and poor disease-free survival rate in HCC.