Prospective flow cytometric DNA analysis of hepatocellular carcinoma specimens collected by ultrasound-guided fine needle aspiration

Gain of GRHL2 is associated with early recurrence of hepatocellular carcinoma

BACKGROUND/AIMS

The aim of this study is to identify genomic changes that might be implicated in hepatocellular carcinoma (HCC) progression, and evaluate the associations with clinico-pathological features.

METHODS

The genomic DNA of 17 hepatoma cell lines was analyzed using Affymetrix GeneChip Human Mapping 50K high-density oligonucleotide arrays. We selected representative genes from recurrent amplified regions and measured the copy number of these genes in 70 HCC clinical samples.

RESULTS

We found 10 recurrent high-grade gain regions spanning less than 3 Mb in at least two hepatoma cell lines, and selected 10 representative genes. The copy number was almost normal in non-cancerous tissue and frequently amplified in Edmondson grade II or III HCC compared to Edmondson grade I HCC. Gain of TAX1BP1 in 7p15.2-1 was associated with larger tumor size and positivity of HCV antibody, and gain of CCND1 in 11q13.2-3 was associated with larger tumor size by multivariate analysis. Furthermore, a gain of GRHL2 in 8q22.3 was associated with early recurrence of HCC, controlling for clinical parameters. Decreased GRHL2 expression by RNA interference inhibits the growth of hepatoma cells, suggesting its association with cell proliferation.

CONCLUSIONS

A gain of GRHL2 might be a predictive marker for HCC recurrence.

Relationship between microvessel count and post-hepatectomy survival in patients with hepatocellular carcinoma

AIM: To elucidate the relationship between the microvessel count (MVC) by CD34 analyzed by immunohistochemical method and prognosis in hepatocellular carcinoma (HCC) patients who underwent hepatectomy based on our preliminary study.

METHODS: We examined relationships between MVC and clinicopathological factors in 128 HCC patients. The modified Japan Integrated Staging score (mJIS) was applied to examine subsets of HCC patients.

RESULTS: Median MVC was 178/mm², which was used as a cut-off value. MVC was not significantly associated with any clinicopathologic factors or postoperative recurrent rate. Lower MVC was associated with poor disease-free and overall survivals by univariate analysis (P = 0.039 and P = 0.087, respectively) and lower MVC represented an independent poor prognostic factor in disease-free survival by Cox’s multivariate analysis (risk ratio, 1.64; P = 0.024), in addition to tumor size, vascular invasion, macroscopic finding and hepatic dysfunction. Significant differences in disease-free and overall survivals by MVC were observed in HCC patients with mJIS 2 (P = 0.046 and P = 0.0014, respectively), but not in those with other scores.

CONCLUSION: Tumor MVC appears to offer a useful prognostic marker of HCC patient survival, particularly in HCC patients with mJIS 2.

Mitotic checkpoint gene MAD1 in hepatocellular carcinoma is associated with tumor recurrence after surgical resection

OBJECTIVE

Underlying mechanism of mitotic checkpoint gene mitosis arrest deficiency 1 (MAD1) in human hepatocellular carcinoma (HCC) is rarely known.

MATERIALS AND METHODS

We studied genetic change of the MAD1 gene as well as protein expression in 44 HCC and their associated non-cancerous surrounding liver tissues.

RESULTS

Genotype AG of MAD1 G-1849 A promoter was highly significant in microscopic vascular invasion than other genotypes (P = 0.006). Moreover, the mean tumor size of HCC with genotype AG (7.71 cm) was significantly larger than those of other genotypes (AA, 4.41 cm; GG, 4.59 cm; P = 0.033). After a median follow-up of 22 months, 18 (41%) of the 44 patients relapsed. Eleven (32.4%) of 34 with MAD1 protein expression and 7 (70%) of 10 with no expression of MAD1 protein showed tumor recurrence. The incidence of tumor recurrence in patients with the lost MAD1 expression was significantly higher than in those with the expressed MAD1 protein (P = 0.011).

CONCLUSION

These results suggest that MAD1 promoter genotype may be involved in tumor progression. Moreover, the loss of MAD1 protein expression may be related to the tumor recurrence after surgical resection of HCC.

Biological characteristics of HCC by ultrasound-guided aspiration biopsy and its clinical application

AIM: To probe the pathological biological characteristics of hepatocellular carcinoma (HCC) by the ultrasound-guided aspiration biopsy and assess the clinical application value of this method.

METHODS: The biopsy and DNA analysis by flow cytometry (FCM) were taken in 46 cases with HCC nodules, including 26 cases and 20 cases with nodules ≤ 3 cm and > 3 cm in diameters respectively, and 12 cases with intrahepatic benign hyperplastic nodules. They were taken in 22 cases of 46 cases with HCC before and after the therapy. Fine-needles and automatic histological incised biopsy needles were used. The fresh biopsy tissue was produced into the single cell suspension, which was sent for DNA detection and ratio analysis of cell period. The ratio of each DNA period of cell proliferation of each group was calculated and compared with each other. The DNA aneuploid (AN) and apoptosis cell peak were observed and their percentages were calculated.

RESULTS: The ratios of S and G₂/M periods of DNA, which reflect cell hyperproliferation, in the group with HCC tumors > 3 cm in diameter were markedly higher than those of the group with HCC nodules ≤ 3 cm in diameter and the group with the benign hyperplastic nodules (P < 0.01 except A:B of S period, P < 0.05). The ratios of the middle group were also apparently higher than those of the latter group (P < 0.01). The ratio of DNA AN of 46 cases with HCC nodules was 34.8% (16/46). None of the cases with the intrahepatic hyperplastic nodules appeared AN. The DNA AN appeared more apparently with the growth of the tumors. The AN ratio of the group with tumors > 3 cm in diameter was 55% (11/20), markedly higher than that of the group with tumors ≤ 3 cm in diameter which was 19.2% (5/26) (P < 0.01). The FCM DNA analysis of 22 specimens of hepatic carcinoma tissue before therapy showed that the aneuploid peaks appeared in 5 cases (22.7%). The ratio of G₁ period rose after therapy while the S period and G₂/M ratios fell (P < 0.01). The aneuploid peak disappeared in the 5 cases after the therapy, while the apoptosis peaks in 12 cases (54.5%) appeared.

CONCLUSION: Addition to supply the information of the pathological morphology of the tumor, the ultrasound-guided fine-needle aspiration tissue could be sent for FCM DNA analysis to comprehend its pathological biological characteristics. This can not only provide the clinic the reliable information about the occurrence, development, diagnosis, curative effect and prognosis of tumors but also supply biological information for clinic to choose therapeutic schemes.

Flow cytometric DNA analysis on fine needle aspiration biopsies of liver lesions

Flow cytometric DNA analysis on fine needle aspiration biopsies of liver lesions The DNA cell content of 39 fine needle aspiration biopsies (FNAs) from five benign liver lesions, nine hepatocellular carcinomas (HCCs), and 25 metastatic tumours was analysed in a prospective fashion by flow cytometry (FCM). All benign lesions were diploid. Aneuploidy was found in five (55.6%) HCCs and in nine (36%) metastatic tumours. DNA index (DI) differences were not significant. The S-phase fraction (SPF) was higher in the malignant tumours, both combined (P < 0.02) and separated primary and metastatic (P < 0.05). We could not demonstrate an association between diploidy and percentage of benign hepatocytes in the smears of malignant tumours. The serum alpha-fetoprotein (AFP) level did not correlate with ploidy, DI, or SPF in the HCCs. In conclusion, ploidy and DI do not discriminate between benign and malignant liver lesions, but the SPF is higher in malignant tumours. DNA analysis does not help to distinguish primary from metastatic liver tumours. The presence of benign hepatocytes in samples from malignant tumours does not seem to influence the analysis of ploidy by FCM.

Frequent impairment of the spindle assembly checkpoint in hepatocellular carcinoma

BACKGROUND

Chromosomal instability (CI) leading to aneuploidy is one form of genetic instability, a characteristic feature of various types of cancers. Recent work has suggested that CI can be induced by a spindle assembly checkpoint defect. The aim of the current study was to determine the frequency of a defect of the checkpoint in hepatocellular carcinoma (HCC) and to establish whether alterations of genes encoding the checkpoint were associated with CI in HCC.

METHODS

Aneuploidy and the function of the spindle assembly checkpoint were examined using DNA flow cytometry and morphologic analysis with microtubule disrupting drugs. To explore the molecular basis, the authors examined the expression and alterations of the mitotic checkpoint gene, BUB1, using Northern hybridization and direct sequencing in 8 HCC cell lines and 50 HCC specimens. Furthermore, the authors examined the alterations of other mitotic checkpoint genes, BUBR1, BUB3, MAD2B, and CDC20, using direct sequencing in HCC cell lines with aneuploidy.

RESULTS

An impaired spindle assembly checkpoint was found in five (62.5%) of the eight aneuploid cell lines. Transcriptional expressions of the BUB1 gene appeared in all cell lines. While some polymorphic base changes were noted in BUB1, BUBR1, and CDC20, no mutations responsible for impairment of the mitotic checkpoint were found in either the HCC cell lines or HCC specimens, which suggests that these genes did not seem to be involved in tumor development in HCC.

CONCLUSIONS

The loss of spindle assembly checkpoint occurred with a high frequency in HCC with CI. However, other mechanisms might also contribute to CI in HCC.

A new prognostic classification for predicting survival in patients with hepatocellular carcinoma. Groupe d'Etude et de Traitement du Carcinome Hépatocellulaire

BACKGROUND/AIMS

In patients with hepatocellular carcinoma, prediction of survival is difficult. The aim of this prospective study was to provide a simple classification for predicting survival of patients with hepatocellular carcinoma, based on a multivariable Cox model.

METHODS

Seven hundred and sixty-one patients who presented with hepatocellular carcinoma from 24 Western medical centers were enrolled over a 30-month period. Patients were randomly assigned to either a training sample (n=506, with 418 deaths) from which a classification system was established, or a test sample (n=255, with 200 deaths) for validating its prognostic significance.

RESULTS

Five prognostic factors were selected at the 0.0001 level: Karnofsky index <80% (relative risk of death=2.2, 95% confidence interval: 1.7-2.7), serum bilirubin >50 micromol/l (relative risk=2.1, 95% confidence interval: 1.7-2.6), serum alkaline phosphatase at least twice the upper limit of normal range (relative risk=1.6, 95% confidence interval: 1.3-2.0), serum alpha-fetoprotein >35 microg/l (relative risk=1.7, 95% confidence interval: 1.4-2.1), and ultrasonographic portal obstruction (relative risk=1.3, 95% confidence interval: 1.1-1.7). Three risk groups with different 1-year survival rates (72%, 34%, 7%) were derived, and independently validated in the test sample (79%, 31%, 4%).

CONCLUSION

This classification could be useful in the assessment of prognosis from homogeneous groups of patients with respect to their expected outcome.

Retrospective evaluation of DNA ploidy of hepatocarcinoma on cytologic samples

DNA ploidy was evaluated by image cytometry in a series of 84 hepatocellular carcinomas diagnosed by fine-needle aspiration biopsy. In the series were included eight cases originally diagnosed as suspect and reclassified as well-differentiated hepatocarcinoma. The study was retrospectively performed on Papanicolaou-destained, Feulgen-restained smears. The 5c exceeding rate and the visual interpretation of the corresponding histograms were evaluated and compared with size of the tumors, serum alpha-fetoprotein values, hepatic functional staging, and patient survival. Sixty-eight cases were aneuploid and 16 euploid (9 diploid and 7 polyploid). Four of the eight cytologically suspect cases were aneuploid. Statistical analysis showed an association between size and cytologic grading, 5c exceeding rate and cytologic grading, and between aneuploidy and multiple tumors; in a Cox multivariate DNA content analysis, aneuploidy and multiple tumors were the two prognostically significant variables. DNA ploidy evaluation by static cytometry of hepatic tumors may be useful in the diagnosis on cytologic samples and could represent an independent prognostic parameter in predicting the survival outcome of patients with hepatocellular carcinoma.

Genomic fluidity is a necessary event preceding the acquisition of tumorigenicity during spontaneous neoplastic transformation of WB-F344 rat liver epithelial cells

The genomic evolution of a cohort of WB-F344 rat liver epithelial cell lineages undergoing spontaneous neoplastic transformation was followed to define the mechanistic relationship between genomic instability and progression to the neoplastic phenotype. Eighteen independent populations of WB-F344 cells (initiated from a single diploid-founding population) were subjected to 12 cycles of selective growth at confluent cell density, and cellular DNA contents were measured after each selection cycle. Flow cytometry demonstrated significant gains in the amount of G1 DNA after selection cycles 3, 6, and 7 in 44% (8 of 18), 89% (16 of 18), and 39% (7 of 18) of the cell populations, respectively. All populations subsequently lost DNA and returned to a diploid or pseudo-diploid DNA content within 1 to 2 selection cycles after the appearance of an increased DNA content. Additionally, appearance and subsequent disappearance of aneuploid or tetraploid subpopulations was observed in 11% (2 of 18) and 83% (15 of 18) of the experimental lineages, respectively. Although perturbations of G1 DNA content were apparent as early as selection cycle 3, at least 8 cycles of selective growth were required for the acquisition of tumorigenicity. While the independent lineages demonstrated significant fluctuations in G1 DNA content between selection cycles 3 and 8, the majority (11 of 13) of the populations contained a diploid or pseudo-diploid DNA content at the time tumorigenicity was expressed. Genomic instability preceded the acquisition of tumorigenic potential in rat liver epithelial cells subjected to selective growth conditions of maintenance at confluence, and may be required for its expression.

Lack of C/EBP alpha gene expression results in increased DNA synthesis and an increased frequency of immortalization of freshly isolated mice [correction of rat] hepatocytes

The CCAAT/enhancer binding protein alpha (C/EBP alpha) binds to specific promoter sequences and directs transcription of many genes expressed in the liver. Overexpression of C/EBP alpha in established cell lines inhibits cell proliferation. Primary hepatocytes from newborn C/EBP alpha(-/-) mice and normal littermates were used to determine whether the absence of C/EBP alpha increased proliferation and/or transformation of these cells in vitro. DNA synthesis, as measured by bromodeoxyuridine (BrdU) incorporation 24 hours postharvest, was fourfold higher in cells from C/EBP alpha(-/-) pups. Established cell lines were derived from 7 of 8 hepatocyte cultures initiated from null mutants, 4 of 23 cultures from heterozygotes, and 0 of 12 cultures from wild-type animals. C/EBP alpha(-/-) cultures had epithelial morphology, showed bile canaliculi, and expressed albumin messenger RNA (mRNA). When cultured on Matrigel, which promotes differentiation, cell lines derived from C/EBP alpha(-/-) mice formed cords and increased albumin mRNA expression by 1.7- to 3.8-fold. C/EBP alpha(-/-) cell lines exhibited rapid growth and rapid accumulation of chromosomal abnormalities, and were capable of forming nodules when inoculated into the abdominal subcutaneous tissue of nude mice. Our data show that C/EBP alpha is an important regulator of hepatocyte proliferation and participates in the maintenance of the nontransformed hepatic phenotype in vitro.

Prognostic influence of clinicopathologic features, DNA-ploidy, CD44H and p53 expression in a large series of resected hepatocellular carcinoma in France

Factors affecting outcome after resection of hepatocellular carcinoma (HCC) in patients from Western countries are not clearly defined. Different clinicopathological factors, including DNA ploidy and expression of p53 and CD44H proteins were evaluated retrospectively in 113 patients undergoing curative resection; 11 clinical and 12 pathological factors were studied. Survival curves were calculated by the Kaplan-Meier method and multivariate analysis of outcome predictors for 103 HCC was assessed by Cox regression. By univariate analysis, survival was significantly better in patients with a high serum albumin level >4.0 g/dl, a normal serum alpha-fetoprotein level and an absence of microscopic vascular invasion by the tumor. In multivariate analysis, only high serum albumin level and absence of vascular invasion were found to be independent favorable predictive factors. CD44H expression was significantly correlated with vascular involvement. However, CD44H and p53 expression did not affect survival. The DNA ploidy pattern showed a bimodal distribution, but did not influence the survival rate. This study suggests that pre-operative level of albumin and microscopic vascular invasion can predict long-term survival in patients who have undergone curative resection for HCC. By contrast, the DNA-ploidy pattern and the immunohistochemical detection of p53 and CD44H expression are not predictors of outcome of patients with HCC.

Interphase cytogenetic analysis reveals numerical chromosome aberrations in large liver cell dysplasia

BACKGROUND/AIMS

Little is known about genetic alterations in large or small liver cell dysplasia. The aim of this study was to determine whether these lesions present numerical chromosome aberrations.

METHODS

Eight patients with hepatocellular carcinoma on cirrhosis, five with large liver cell dysplasia and three with small liver cell dysplasia, were analysed by in situ hybridization with different centromeric nucleic acid probes specific respectively for chromosomes 1, 7, 17 and 18. In each case results were compared between dysplastic, tumoral and non-dysplastic cirrhotic cells. Four normal livers were also studied with the same method and served as cytogenetic controls.

RESULTS

All cases of large liver cell dysplasia dysplayed a polysomic population for each investigated chromosome. A high variability of numerical chromosome aberrations was observed with a copy number of chromosomes which ranged from two to more than six. By contrast, only one case of small liver cell dysplasia showed chromosomal anomalies. Numerical aberrations of at least one chromosome were observed in six of the eight hepatocellular carcinoma while the non-dysplastic cirrhosis and normal liver always showed a diploid pattern.

CONCLUSIONS

These results demonstrate that cellular modifications in large liver cell dysplasia coexist with an early acquisition of genomic alterations, supporting the view that these phenotypic changes are preneoplastic.

Alteration of DNA ploidy and cell nuclearity in human hepatocellular carcinoma associated with HBV infection

BACKGROUND/AIMS

Hepatocellular carcinoma usually arises in cirrhotic livers as a complication of chronic liver disease, and may show a variable trend towards increasing ploidy. The aim of this study was to investigate possible associations between different etiological factors, particularly hepatitis B virus and hepatitis C virus infection, and alteration of DNA-ploidy and nuclearity of neoplastic hepatocytes.

METHODS

DNA-ploidy, the percentage of binucleated cells in the total cell population and the fraction of mononucleated hepatocytes in the polyploid compartment were assessed by image cytometry on cellular suspensions obtained by fine-needle biopsy from 60 hepatocellular carcinomas in patients whose viral status had previously been assessed.

RESULTS

Significantly higher DNA-ploidy values (p = 0.005), with a reduction in the percentage of binucleated hepatocytes (p = 0.003) and an increase in the fraction of mononucleated hepatocytes in the polyploid compartment (p < 0.0001), were found in hepatocellular carcinoma with actual or previous hepatitis B virus infection (including also HCV+ve patients) in comparison to those not associated with hepatitis B virus infection, but not when HCV+ve hepatocellular carcinomas were compared to HCV-ve ones. Statistically significant differences for ploidy values (p < 0.05), percentage of binucleated hepatocytes (p < 0.05) and fraction of mononucleated hepatocytes in the polyploid compartment (p = 0.003) were also found between hepatocellular carcinoma associated only to hepatitis B virus infection ("pure" hepatitis B virus cases) and those associated only to hepatitis C virus infection ("pure" hepatitis C virus cases).

CONCLUSIONS

Hepatocellular carcinoma associated with a previous or actual hepatitis B virus infection shows a peculiar phenotypical appearance, characterized by a trend towards increasing ploidy and reduction of binuclearity.

Cytogenetic analyses of hepatocellular carcinoma by in situ hybridization with a chromosome-specific DNA probe

BACKGROUND

Numerical chromosome analysis has been established in solid tumors by using in situ hybridization (ISH) with a chromosome-specific probe. We analyzed human hepatocellular carcinoma (HCC) by ISH for chromosome 17 and investigated the correlation of its copy number with histologic malignancy, proliferative activity, p53 mutation, and DNA ploidy.

METHODS

Chromosome 17 was hybridized with a pericentromere-specific DNA probe directly on the tumor cells isolated from paraffin blocks of 25 surgically resected HCCs. Proliferative activity was measured by Ki-67 immunohistochemistry, p53 mutation was analyzed by p53 immunohistochemistry, and DNA ploidy was estimated by cytofluorometry.

RESULTS

Forty-four percent of the 25 HCCs showed numerical abnormality of chromosome 17. Many disomic cases had a less malignant histology, whereas many polysomic cases had a more malignant histology. The Ki-67 positive index of polysomic cases was higher than that of disomic cases. In 22 cases (88.0%), the copy number of chromosome 17 was well matched with DNA ploidy. However, the numerical abnormality of chromosome 17 did not show a significant correlation with p53 mutation. Two of four HCCs that showed histologic heterogeneity were also heterogenous on ploidy pattern and the copy number of chromosome 17. Conversely, there was one case in which only ISH could demonstrate heterogeneity, although the other features exhibited homogeneity.

CONCLUSIONS

Numerical chromosome abnormalities correlated with the increase of histologic malignancy proliferative activity, and DNA ploidy. Moreover, ISH analysis was useful in assessing the intratumoral heterogeneity in HCC, especially when current methods failed to detect it. Thus, ISH provides information on important biologic features, such as malignant potential and intratumoral heterogeneity, in HCC.

[DNA content of the tumor cell. A new prognostic parameter in hepatocellular carcinoma?]

Hepatocellular carcinoma is a heterogeneous disease with considerable differences in malignant behaviour. Some relevant factors for prognosis are known. In this study we analysed DNA ploidy as a potential prognostic parameter. With DNA image cytometry we were able to differentiate between diploid, hypotriploid, triploid, hypertriploid, tetraploid and aneuploid tumours. The best prognosis was for patients with diploid, hypotriploid and tetraploid tumours with a median survival time of 41 months in contrast to 3 months for patients with triploid, hypertriploid or aneuploid tumours. There was a strong correlation between histomorphological parameters and the DNA content. The DNA content of tumour cells may be considerable clinical relevance in hepatocellular carcinoma regarding the decision as to whether or not to perform a resection. In patients with prognostically unfavorable parameters adjuvant oncological therapy may improve the prognosis.

DNA flow cytometry in patients undergoing liver transplantation for hepatocellular carcinoma

The purpose of the study was to analyse patterns of DNA content in hepatocellular carcinomas (HCC) submitted to orthotopic liver transplantation (OLT). Paraffin-embedded archival material from 15 patients (ten men, five women, mean age 51 +/- 1.78 years) transplanted in St-Roch Hospital between 1988 and 1991 was available for laboratory evaluation by flow cytometry. Five out of 15 were incidental HCC. The analysis was performed by a FACSscan flow cytometer coupled to a Hewlett-Packard computer. The cellular DNA content was defined as diploid or aneuploid in the presence of a single (DNA index of 1) or two distinct (DNA index different from 1) Gzero/G1 peaks, respectively. All incidental HCC (five patients) were diploid, the tumour size was 1.2 +/- 0.2 cm, the number of nodules was 1.4 +/- 0.24 and the mortality rate was 40%. No death in the incidental HCC group was related to neoplastic recurrence. In the remaining ten patients transplanted for HCC, we observed 50% diploid tumours, the tumour size was 5.2 +/- 1.55 cm and the number of nodules was 2.7 +/- 0.56. In this group six patients died of neoplastic recurrence (two were diploid and four aneuploid). The diameter of the neoplasm in diploid patients who died of neoplastic recurrence was over 5 cm and the number of nodules was over three. Moreover, in aneuploid patients who died of neoplastic recurrence, the diameter of the neoplasm was less than 5 cm in three cases and the number of nodules was less than three in two patients. This study indicates that incidental HCC may be a less aggressive malignancy and may have a better prognosis. In this group, no patient recurred after OLT and all tumours were diploid. Aneuploidy, tumour size (> 5 cm) and number of lesions (> 3) are prognostic indicators for neoplastic recurrence in patients transplanted for hepatocellular carcinoma.