Expression and prognostic role of tumor suppressor gene PTEN/MMAC1/TEP1 in hepatocellular carcinoma

Non-alcoholic steatohepatitis and hepatocellular carcinoma: lessons from hepatocyte-specific phosphatase and tensin homolog (PTEN)-deficient mice

Non-alcoholic steatohepatitis (NASH) is a term used to describe a spectrum of conditions characterized by histological findings of hepatic macrovesicular steatosis with inflammation in individuals who consume little or no alcohol. The NASH patients progress to liver cirrhosis and even hepatocellular carcinoma (HCC). Hepatocyte-specific phosphatase and tensin homolog (PTEN)-deficient mice (PTEN-deficient mice), which the authors had generated previously, showed massive hepatomegaly and steatohepatitis with triglyceride accumulation followed by liver fibrosis and HCC, a phenotype similar to human NASH. Therefore, it was shown that PTEN deficiency in hepatocytes could induce hepatic steatosis, inflammation, fibrosis and tumors and that PTEN-deficient mice were a useful animal model for not only the understanding of the pathogenesis of NASH but also the development of treatment for NASH.

Biología celular y genética en el cáncer de hígado

Hepatocellular carcinoma (HCC) is the main cause of death in cirrhotic patients and has become a major health problem in developed countries. Analysis of the somatic alterations and gene expression profiles in patients with HCC have provided important information the genes involved in liver carcinogenesis. Nevertheless, the most important molecular alterations in the initial stages of the disease are currently unknown. The application of high resolution technologies to other forms of cancer (genome analysis with oligo microarrays and SNP arrays) should lead to greater insight into the pathogenesis of this neoplasm. In the last few years, distinct signaling pathways involved in hepatocarcinogenesis have been identified. Among these, the Wnt, EGFR and PI3k/akt/mTOR pathways are constitutively altered in numerous studies, providing the molecular basis for the molecular treatment of this tumor. As in other neoplasms, the original tumor cell in HCC is controversial. The most widely accepted hypothesis suggests that numerous genomic alterations in the hepatocyte cells lead to a neoplastic phenotype. Alternatively, it has been postulated that at least a subgroup of tumors could be of stem cell origin. Both hypotheses agree on the existence of cancer stem cells, arising from the original tumor cell; these cancer stem cells would then perpetuate and disseminate the neoplasm. This review summarizes the most important information on the structural and functional alterations in HCC and describes some of the main signaling pathways implicated in liver cancer.

Prognostic molecular markers in hepatocellular carcinoma: a systematic review

Hepatocellular carcinoma (HCC) is the fifth commonest malignancy worldwide and its incidence is rising. Surgery, including transplantation, remains the only potentially curative modality for HCC, yet recurrence rates are high and long-term survival poor. The ability to predict individual recurrence risk and subsequently prognosis would help guide surgical and chemotherapeutic treatment. As understanding of hepatocarcinogenesis has increased, the myriad of genetic and molecular events that drive the hepatocarcinogenic disease process, including angiogenesis, invasion and metastasis, have been identified. This systematic review examines the evidence from published manuscripts reporting the prognostic potential of molecular biomarkers in hepatocellular carcinoma. In summary, a number of molecular biomarkers with prognostic significance have been identified in hepatocellular carcinoma. Not only might these molecules allow more accurate prediction of prognosis for patients with HCC, but they may also provide targets for potential therapeutic agents.

Roles of reactive oxygen species in hepatocarcinogenesis and drug resistance gene expression in liver cancers

Hepatocellular carcinoma (HCC) has traditionally been an attractive system for cancer research because many animal HCC models are available. It is well known that liver tumors in animals can be induced by many different protocols, such as chronic hepatitis viral infections, carcinogens, toxins, steroid hormones, and dietary intervention. Although these different inducers have different cellular targets and modes of cytotoxic effects, their common denominator is the formation of reactive oxygen species (ROS). In this review, we present compelling evidence to support the hypothesis that ROS play important roles in hepatocarcinogenesis and the associated upregulation of drug resistance gene expression.

New therapies for hepatocellular carcinoma

Hepatocellular carcinoma (HCC), one of the most common cancers worldwide, is often diagnosed at an advanced stage when most potentially curative therapies such as resection, transplantation or percutaneous and transarterial interventions are of limited efficacy. The fact that HCC is resistant to conventional chemotherapy, and is rarely amenable to radiotherapy, leaves this disease with no effective therapeutic options and a very poor prognosis. Therefore, the development of more effective therapeutic tools and strategies is much needed. HCCs are phenotypically and genetically heterogeneous tumors that commonly emerge on a background of chronic liver disease. However, in spite of this heterogeneity recent insights into the biology of HCC suggest that certain signaling pathways and molecular alterations are likely to play essential roles in HCC development by promoting cell growth and survival. The identification of such mechanisms may open new avenues for the prevention and treatment of HCC through the development of targeted therapies. In this review we will describe the new potential therapeutic targets and clinical developments that have emerged from progress in the knowledge of HCC biology, In addition, recent advances in gene therapy and combined cell and gene therapy, together with new radiotherapy techniques and immunotherapy in patients with HCC will be discussed.

Serum tumor markers for detection of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most frequent malignant tumors and is the second most common cause of cancer death in China. Therefore, it is very important to detect this disease and the recurrence at its earlier period. Serum tumor markers, as the effective method for detecting hepatocellular carcinoma for a long time, could be divided into 4 categories: oncofetal antigens and glycoprotein antigens; enzymes and isoenzymes; genes; and cytokines. Serum alpha fetoprotein (AFP) is the most widely used tumor marker in detecting patients with hepatocellular carcinoma, and has been proven to have capability of prefiguring the prognosis. However, it has been indicated that AFP-L3 and DCP excel AFP in differentiating hepatocellular carcinoma from nonmalignant hepatopathy and detecting small hepatocellular carcinoma. Some tumor markers, such as human cervical cancer oncogene and human telomerase reverse transcriptase mRNA, have also been indicated to have higher accuracies than AFP. Furthermore, some other tumor markers, such as glypican-3, gamma-glutamyl transferase II, alpha-l-fucosidase, transforming growth factor-beta1, tumor-specific growth factor, have been indicated to be available supplementaries to AFP in the detection. AFP mRNA has been shown to correlate with the metastasis and recurrence of HCC, and it may be the most useful marker to prefigure the prognosis. Some other markers, such as gamma-glutamyl transferase mRNA, vascular endothelial growth factor, and interleukin-8, could also be used as available prognostic indicators, and the simultaneous determination of AFP and these markers may detect the recurrence of HCC at its earlier period.

AMPK, the metabolic syndrome and cancer

The fuel-sensing enzyme 5'-AMP-activated protein kinase (AMPK) has a major role in the regulation of cellular lipid and protein metabolism in response to stimuli such as exercise, changes in fuel availability and the adipocyte-derived hormones leptin and adiponectin. Recent studies indicate that abnormalities in cellular lipid metabolism are involved in the pathogenesis of the metabolic syndrome, possibly because of dysregulation of AMPK and malonyl-CoA, a closely related molecule. As we discuss in this article, several findings also point to a link between AMPK and the growth and/or survival of some cancer cells. Thus, it has been demonstrated recently that the tumor suppressor LKB1 is a kinase that has a major role in phosphorylating and activating AMPK, and that another tumor suppressor, tuberous sclerosis complex 2, is phosphorylated and activated by AMPK. In addition, other studies indicate that mammalian homolog of target of rapamycin (mTOR), which has been implicated in the pathogenesis of insulin resistance and many types of cancer, is inhibited by AMPK.

High frequency of submicroscopic hemizygous deletion is a major mechanism of loss of expression of PTEN in uveal melanoma

PURPOSE

Although cytogenetic aberrations at 10q have been reported in up to 27% of uveal melanomas, the role of PTEN in the pathogenesis of uveal melanoma is largely unknown. Our aim was to determine the frequency and clinical significance of PTEN alterations in uveal melanomas.

PATIENTS AND METHODS

We examined PTEN expression using immunohistochemistry in 75 sporadic uveal melanomas, with an average follow-up of 89 months. Molecular cytogenetic alterations were studied using comparative genomic hybridization (CGH). Genotyping was carried out using an intragenic PTEN marker and two flanking markers. Mutational analysis of PTEN was also carried out.

RESULTS

Of the 75 tumors, 12 (16%) showed no PTEN immunostaining, 32 (42.7%) showed weak to moderate staining and the remaining 31 (38.2%) showed staining similar to the normal internal controls. Using CGH, only two (15.4%) of 13 samples showed any loss of 10q. However, in the 38 tumors with informative genotyping, we found that 29 (76.3%) had loss of heterozygosity (LOH) of at least one PTEN marker, and 15 (39.5%) showed LOH of at least two markers. Mutations in the coding region of PTEN were identified in four (11.4%) of 35 tumors. Further, loss of cytoplasmic PTEN expression by immunohistochemistry was associated with shortened disease-free survival (P = .029).

CONCLUSION

This is the first demonstration that PTEN is a tumor suppressor involved in uveal melanoma pathogenesis and may be associated with clinical outcome. Our data also suggest that submicroscopic deletion, but not large deletions, is the major mechanism of loss of PTEN expression in uveal melanomas.

Hepatocellular carcinoma as a complex polygenic disease. Interpretive analysis of recent developments on genetic predisposition

The different frequency of hepatocellular carcinoma (HCC) in humans at risk suggests a polygenic predisposition. However, detection of genetic variants is difficult in genetically heterogeneous human population. Studies on mouse and rat models identified 7 hepatocarcinogenesis susceptibility (Hcs) and 2 resistance (Hcr) loci in mice, and 7 Hcs and 9 Hcr loci in rats, controlling multiplicity and size of neoplastic liver lesions. Six liver neoplastic nodule remodeling (Lnnr) loci control number and volume of re-differentiating lesions in rat. A Hcs locus, with high phenotypic effects, and various epistatic gene-gene interactions were identified in rats, suggesting a genetic model of predisposition to hepatocarcinogenesis with different subset of low-penetrance genes, at play in different subsets of population, and a major locus. This model is in keeping with human HCC epidemiology. Several putative modifier genes in rodents, deregulated in HCC, are located in chromosomal segments syntenic to sites of chromosomal aberrations in humans, suggesting possible location of predisposing loci. Resistance to HCC is associated with lower genomic instability and downregulation of cell cycle key genes in preneoplastic and neoplastic lesions. p16(INK4A) upregulation occurs in susceptible and resistant rat lesions. p16(INK4A)-induced growth restraint was circumvented by Hsp90/Cdc37 chaperons and E2f4 nuclear export by Crm1 in susceptible, but not in resistant rats and human HCCs with better prognosis. Thus, protective mechanisms seem to be modulated by HCC modifiers, and differences in their efficiency influence the susceptibility to hepatocarcinogenesis and probably the prognosis of human HCC.

Reduced Expression of PTEN Protein and Its Prognostic Implications in Invasive Ductal Carcinoma of the Breast

OBJECTIVE

The PTEN tumor suppressor gene has been demonstrated to be inactivated in a variety of human tumors. In breast cancer, the PTEN gene mutation is not commonly found whereas loss of heterozygosity affecting the PTEN locus is frequently found. The aim of this study was to analyze PTEN protein expression in breast cancer and to evaluate the prognostic significance of PTEN protein expression.

METHODS

Paraffin-embedded sections ofinvasive ductal carcinoma of the breast were immunohistochemically stained for PTEN protein expression in 236 breast cancers. The immunohistochemical expression of breast cancer cells was judged to be either normal or reduced compared with the PTEN protein expression of the normal mammary gland.

RESULTS

The expression of PTEN protein was found to have decreased in 67 (28%) of 236 breast cancers. The reduced expression correlated with lymph node metastasis (p = 0.0371), but not with tumor size, nuclear grade, MIB-1 counts or p53 protein expression. Univariate analysis indicated that patients with a reduced PTEN expression had a shorter disease-free survival (DFS) than those with a normal PTEN expression (p = 0.0174). Univariate analyses also determined tumor size, lymph node metastases, nuclear grade, MIB-1 counts, p53 protein as well as PTEN protein expression to be significant factors for DFS, while multivariate analysis determined lymph node metastases and the MIB-1 counts to be independent significant factors for DFS.

CONCLUSIONS

The inactivation of PTEN, demonstrated by a reduced expression of PTEN protein by immunohistochemistry, was found in about one third of all breast cancers. The reduced expression of PTEN protein correlated with lymph node metastases and a worse prognosis in the patients with breast cancer.

Increased endostatin/collagen XVIII expression correlates with elevated VEGF level and poor prognosis in hepatocellular carcinoma

Liver is the primary source for collagen XVIII, the precursor of angiogenesis inhibitor, endostatin. However, the role of endostatin/collagen XVIII expression during liver carcinogenesis remains elusive. Therefore, we studied its expression in five hepatoma cell lines and 105 hepatocellular carcinoma specimens. The poorly differentiated hepatoma cell lines exhibited increased endostatin/collagen XVIII levels compared with the well-differentiated ones. In hepatoma tissues, endostatin/collagen XVIII expression was detected in various types of liver cells and was significantly stronger in adjacent nontumor tissues than that in tumors (P<0.001). Endostatin/collagen XVIII expression in nontumor tissues correlated with tumor stages (P=0.014) and expression of vascular endothelial growth factor (P=0.007), but not the stages of hepatic fibrosis (P>0.05). Kaplan-Meier analysis showed that patients with higher endostatin/collagen XVIII expression had significantly shorter overall survival (P=0.011) and disease-free survival (P=0.0034). Moreover, endostatin/collagen XVIII level was an independent prognostic factor for tumor recurrence (P=0.034) by multivariate analysis. In conclusion, increased endostatin/collagen XVIII expression correlated with hepatoma progression and predicted poor prognosis for patients with hepatocellular carcinoma.

Genetic and epigenetic alterations of the PTEN gene in soft tissue sarcomas☆

The PTEN/MMAC1 ( PTEN ) gene was identified as a tumor suppressor gene encoding a cytoplasmic protein that controls cellular processes. To investigate the potential role and the alteration of the PTEN gene in soft tissue sarcomas (STSs), we searched for homozygous deletion and promoter hypermethylation in a series of 48 STSs that was composed of malignant fibrous histiocytoma, leiomyosarcoma, malignant peripheral nerve sheath tumor, including 2 cases with a mutation that we previously reported; differential polymerase chain reaction and methylation-specific polymerase chain reaction, respectively, were used for the analyses. Furthermore, to determine whether PTEN gene alterations are involved in the down-regulation of PTEN expression, we examined the expression of PTEN protein in 38 cases in which paraffin-embedded tissues were available for immunohistochemical analysis. In addition to our previous results showing that 2 (4%) of 51 cases had a PTEN mutation, promoter methylation was recognized in 6 (13%) of 48 cases, and homozygous deletion was detected in 1 (2%) of 48 cases in the current study. Of 6 cases with promoter methylation of PTEN gene, 5 were malignant peripheral nerve sheath tumor. Decreased expression of PTEN protein was recognized in 11 (29%) of 38 STS cases. Of 9 cases with PTEN alterations (6 cases with promoter methylation, 2 with mutation, and 1 with homozygous deletion), 3 (33%) showed decreased expression of PTEN protein. Furthermore, decreased expression of the PTEN gene showed a statistically significant correlation with high MIB-1 labeling index in 38 STS cases examined ( P = .0441). In conclusion, promoter methylation and homozygous deletion of the PTEN gene were found to be relatively rare events in cases of STS, as is mutation of the gene. Of 9 cases with a PTEN alteration, 3 (33%) showed a decrease in PTEN expression, indicating that PTEN gene alterations seem to play a minor role in the inactivation of PTEN in these tumors. Furthermore, although a further detailed analysis of a larger number of cases is still necessary, the present results suggest that PTEN expression may be a useful indicator of cell proliferation in patients with STS.

Antibody-based profiling of the phosphoinositide 3-kinase pathway in clinical prostate cancer

PURPOSE

As kinase inhibitors transition from the laboratory to patients, it is imperative to develop biomarkers that can be used in the clinic. The primary objectives are to identify patients most likely to benefit from molecularly targeted therapies and to document modulation of the drug target. Constitutive activation of the phosphoinositide 3-kinase (PI3K) pathway and its downstream effectors, as a result of PTEN loss or by other mechanisms, occurs in a high proportion of prostate cancers, making it an ideal template for the design of clinical trials involving PI3K pathway inhibitors. Prostate cancers also present unique organ-specific challenges, in that tumors are heterogeneous and diagnostic tissue is extremely limited.

EXPERIMENTAL DESIGN

Working within these limitations, we have developed a set of immunohistochemical assays that define activation of the PI3K pathway in clinical samples.

RESULTS AND CONCLUSIONS

Using both univariate and multivariate analyses, we show that loss of PTEN is highly correlated with the activation of AKT, and this, in turn, is associated with the phosphorylation of S6, one of its main effectors. These three antibodies are potentially able to define a molecular signature of PTEN loss and/or AKT pathway activation in prostate cancer.

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.

Hepatocyte-specific Pten deficiency results in steatohepatitis and hepatocellular carcinomas

PTEN is a tumor suppressor gene mutated in many human cancers, and its expression is reduced or absent in almost half of hepatoma patients. We used the Cre-loxP system to generate a hepatocyte-specific null mutation of Pten in mice (AlbCrePten(flox/flox) mice). AlbCrePten(flox/flox) mice showed massive hepatomegaly and steatohepatitis with triglyceride accumulation, a phenotype similar to human nonalcoholic steatohepatitis. Adipocyte-specific genes were induced in mutant hepatocytes, implying adipogenic-like transformation of these cells. Genes involved in lipogenesis and beta-oxidation were also induced, possibly as a result of elevated levels of the transactivating factors PPARgamma and SREBP1c. Importantly, the loss of Pten function in the liver led to tumorigenesis, with 47% of AlbCrePten(flox/flox) livers developing liver cell adenomas by 44 weeks of age. By 74-78 weeks of age, 100% of AlbCrePten(flox/flox) livers showed adenomas and 66% had hepatocellular carcinomas. AlbCrePten(flox/flox) mice also showed insulin hypersensitivity. In vitro, AlbCrePten(flox/flox) hepatocytes were hyperproliferative and showed increased hyperoxidation with abnormal activation of protein kinase B and MAPK. Pten is thus an important regulator of lipogenesis, glucose metabolism, hepatocyte homeostasis, and tumorigenesis in the liver.

Hepatocyte-specific Pten deficiency results in steatohepatitis and hepatocellular carcinomas

PTEN is a tumor suppressor gene mutated in many human cancers, and its expression is reduced or absent in almost half of hepatoma patients. We used the Cre-loxP system to generate a hepatocyte-specific null mutation of Pten in mice (AlbCrePten(flox/flox) mice). AlbCrePten(flox/flox) mice showed massive hepatomegaly and steatohepatitis with triglyceride accumulation, a phenotype similar to human nonalcoholic steatohepatitis. Adipocyte-specific genes were induced in mutant hepatocytes, implying adipogenic-like transformation of these cells. Genes involved in lipogenesis and beta-oxidation were also induced, possibly as a result of elevated levels of the transactivating factors PPARgamma and SREBP1c. Importantly, the loss of Pten function in the liver led to tumorigenesis, with 47% of AlbCrePten(flox/flox) livers developing liver cell adenomas by 44 weeks of age. By 74-78 weeks of age, 100% of AlbCrePten(flox/flox) livers showed adenomas and 66% had hepatocellular carcinomas. AlbCrePten(flox/flox) mice also showed insulin hypersensitivity. In vitro, AlbCrePten(flox/flox) hepatocytes were hyperproliferative and showed increased hyperoxidation with abnormal activation of protein kinase B and MAPK. Pten is thus an important regulator of lipogenesis, glucose metabolism, hepatocyte homeostasis, and tumorigenesis in the liver.

p53 immunostaining pattern in Brazilian patients with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is an important type of cancer etiologically related to some viruses, chemical carcinogens and other host or environmental factors associated to chronic liver injury in humans. The tumor suppressor gene p53 is mutated in highly variable levels (0-52%) of HCC in different countries.

OBJECTIVE

The objective of the present study was to compare the frequency of aberrant immunohistochemical expression of p53 in HCC occurring in cirrhotic or in non-cirrhotic patients as well as in liver cell dysplasia and in adenomatous hyperplasia. We studied 84 patients with HCC or cirrhosis.

RESULTS

We detected p53 altered immuno-expression in 58.3% of patients in Grade III-IV contrasting to 22.2% of patients in Grade I-II (p = 0.02). Nontumorous areas either in the vicinity of HCC or in the 30 purely cirrhotic cases showed no nuclear p53 altered expression, even in foci of dysplasia or adenomatous hyperplasia. No significant difference was found among cases related to HBV, HCV or alcohol.

CONCLUSION

The high frequency of p53 immunoexpression in this population is closer to those reported in China and Africa, demanding further studies to explain the differences with European and North American reports.

Predictive value of biological markers for hepatocellular carcinoma patients treated with orthotopic liver transplantation

PURPOSE

To help stratify candidates with hepatocellular carcinoma (HCC) for orthotopic liver transplantation (OLT), biomarkers are needed that are capable of predicting recurrence of disease (ROD). We investigated the prognostic role in this setting of immunohistochemical markers reported previously to predict poor prognosis in HCC patients treated with resection.

EXPERIMENTAL DESIGN

Eighty-three patients with HCC who underwent OLT between 1987 and 2001 with a minimum clinical follow up of 12 months were included in this retrospective study. We analyzed immunohistochemical expression of the adhesion molecules E-cadherin and beta-catenin (membrane/nuclear localization), MIB-1 proliferative index and the cyclin-dependent kinase inhibitor p27, alongside the main clinical-pathological variables.

RESULTS

At univariate analysis, vascular thrombosis, high MIB-1 index, lower membrane expression of E-cadherin and beta-catenin, and nuclear beta-catenin localization were associated with ROD. At multivariate analysis, only MIB-1 index, low equal E-cadherin (with respect to non-neoplastic surrounding tissue), and nuclear beta-catenin appeared as independent predictors of ROD. The logistic regression analysis model indicated that detection of any one parameter was associated with at least 88% estimated risk of ROD (up to 99% for all three).

CONCLUSIONS

We propose these three molecular parameters as an additional tool for rational selection of OLT candidates among HCC patients (stratification according to the risk of ROD might help provide a similar life expectancy for cirrhotic candidates with and without HCC).

Expression of hepatoma-derived growth factor in hepatocellular carcinoma

BACKGROUND

Hepatoma-derived growth factor (HDGF) is a novel growth factor derived from a hepatoma cell line. The current study was designed to elucidate the role of HDGF expression during the pathogenesis of hepatocellular carcinoma (HCC).

METHODS

HDGF expression in hepatoma cell lines was analyzed using the reverse transcriptase-polymerase chain reaction (RT-PCR), Western blot analysis, and immunofluorescence analysis. Immunohistochemical studies were performed to examine the intensity and spatial distribution of HDGF immunostaining in 105 HCC specimens. To evaluate its prognostic value, the labeling index of HDGF immunostaining was analyzed for potential correlations with the clinicopathologic characteristics of HCC.

RESULTS

RT-PCR and Western blot analysis detected increased HDGF expression in malignant hepatoma cell lines. In resected HCC specimens, HDGF immunostaining was detected in the nuclei and cytoplasm of hepatocytes and hepatoma cells. HDGF levels in hepatoma tissue samples were significantly higher than in adjacent nontumor tissue samples (P < 0.05). Elevated nuclear HDGF levels were found to be correlated with loss of differentiation features (P < 0.05), absence of tumor capsules (P < 0.01), high alpha-fetoprotein levels (P < 0.05), and overexpression of proliferating cell nuclear antigen (P < 0.001). Kaplan-Meier analysis indicated that patients with higher nuclear HDGF levels had a shorter duration of survival and a higher incidence of recurrence (P < 0.001). Multivariate analysis indicated that for patients with HCC, the nuclear HDGF level is an independent prognostic factor for overall and disease-free survival.

CONCLUSIONS

Increased HDGF expression is correlated with the proliferating states of HCC and represents a novel prognostic factor for patients with HCC who have undergone surgery.