Novel blood-based, five-gene biomarker set for the detection of colorectal cancer.

PURPOSE: We applied a unique method to identify genes expressed in whole blood that can serve as biomarkers to detect colorectal cancer (CRC). EXPERIMENTAL DESIGN: Total RNA was isolated from 211 blood samples (110 non-CRC, 101 CRC). Microarray and quantitative real-time PCR were used for biomarker screening and validation, respectively. RESULTS: From a set of 31 RNA samples (16 CRC, 15 controls), we selected 37 genes from analyzed microarray data that differed significantly between CRC samples and controls (P < 0.05). We tested these genes with a second set of 115 samples (58 CRC, 57 controls) using quantitative real-time PCR, validating 17 genes as differentially expressed. Five of these genes were selected for logistic regression analysis, of which two were the most up-regulated (CDA and MGC20553) and three were the most down-regulated (BANK1, BCNP1, and MS4A1) in CRC patients. Logit (P) of the five-gene panel had an area under the curve of 0.88 (95% confidence interval, 0.81-0.94). At a cutoff of logit (P) >+0.5 as disease (high risk), <-0.5 as control (low risk), and in between as an intermediate zone, the five-gene biomarker combination yielded a sensitivity of 94% (47 of 50) and a specificity of 77% (33 of 43). The intermediate zone contained 22 samples. We validated the predictive power of these five genes with a novel third set of 92 samples, correctly identifying 88% (30 of 34) of CRC samples and 64% (27 of 42) of non-CRC samples. The intermediate zone contained 16 samples. CONCLUSION: Our results indicate that the five-gene biomarker panel can be used as a novel blood-based test for CRC.

Correlative Analysis of DNA Methyltransferase Expression and Promoter Hypermethylation of Tumor Suppressor Genes in Hepatocellular Carcinoma.

BACKGROUND: Promoter hypermethylation of tumor suppressor genes (TSGs) is a common phenomenon in liver carcinogenesis, although the controlling mechanism remains unclear. MATERIALS AND METHODS: The mRNA expression of DNA methyltransferases (DNMT1, 2, 3a, 3b and splice variants 3b3 and 3b4) and methyl-CpG binding protein (MBD2) were quantitated in 51 liver specimens (41 hepatocellular carcinoma (HCC), 1 cholangiocarcinoma, 1 macroregenerative nodule and 8 HCC cell lines) and the expression levels were correlated with the promoter methylation status of 14 TSG, including APC, RASSF1A, SOCS-1, GSTP1, E-cadherin, p14, p15, p16, DAP-kinase, HIC1, MGMT, TIMP-3, hMLH1 and HLTF. RESULTS: Up-regulations of DNMT1, DNMT2, DNMT3a, DNMT3b4 and MBD2 were suggested in more than 40% of the cases. In particular, the overexpression of DNMT3b and the splice variant DNMT3b3 were identified in as many as 91% and 97.8% of cases, respectively. Using methylation-specific PCR, the most frequently methylated TSGs were APC (90.2%), RASSF1A (86.3%), SOC-1 (74.5%), GSTP1 (72.5%), E-cadherin (64.7%) and p16 (58%). Statistical correlations did not suggest the DNMTs and MBD2 expressions in association with cumulative methylated index in individual cases, but increased expression levels of DNMT2 and DNMT3a showed significant association with the hypermethylation of GSTP1 (p=0.014) and DAP-kinase (p=0.006), respectively. Furthermore, the analysis with clinicopathological data indicated aberrant DAP-kinase methylation was significantly associated with advanced stage T3/T4 HCC tumors (p=0.032) and that p16 hypermethylation was distinct more prevalent in tumors arising from a cirrhotic background (p=0.005). CONCLUSION: Our study indicated that DNMT deregulations are common in liver cancers and the existence of a relationship between DNMT2 and DNMT3a overexpression and promoter hypermethylation of candidate tumor suppressor genes in HCC.

[Hypermethylation of fragile histidine triad gene and 3p14 allelic deletion in ovarian carcinomas].

OBJECTIVE: The FHIT (fragile histidine triad) is a candidate tumor suppressor gene (TSG) located on chromosome 3p14.2. Hypermethylation and loss of heterozygosity (LOH) are major mechanisms in the inactivation of tumor suppressor genes. In this study, the methylation status of FHIT and LOH of 3p14 in 61 cases of human sporadic ovary carcinomas were investigated. METHODS: Sixty-one primary ovary carcinomas and 10 borderline ovarian tumors were analyzed with methylation specific PCR (MSP) to detect the CpG island methylation status in the FHIT promoter region. In addition, 45 cases of ovary carcinomas and their corresponding non-tumor ovary tissues were investigated with D3S1287 microsatellite polymorphic marker for LOH. RESULTS: Hypermethylation of FHIT gene was observed in 39.3% (24/61) of ovarian carcinomas. The frequencies of hypermethylation in serous ovarian carcinoma, mucinous ovarian carcinoma, endometrioid ovarian carcinoma and ovary borderline tumor were 45.2% (19/42), 14.3% (1/7), 33.3% (4/12) and 60.0% (6/10), respectively. Ten of twenty-three (43.5%) informative tumors showed LOH and 6 of 18 (33.3%) informative cases showed homozygous deletions. The status of FHIT methylation was not associated with clinical stage and differentiation grade, there was no significant difference between the malignant and borderline tumors. CONCLUSION: Hypermethylation and allelic deletion of FHIT are frequent events in ovarian carcinomas and are important mechanisms for the loss of expression of this gene.

Intrahepatic hepatitis B virus covalently closed circular DNA can be a predictor of sustained response to therapy.

BACKGROUND & AIMS: This study aimed to determine whether intrahepatic hepatitis B virus (HBV) covalently closed circular (ccc) DNA and total HBV DNA levels at the end of therapy would predict sustained response to therapy. METHODS: Hepatitis B e antigen (HBeAg)-positive chronic hepatitis B patients receiving either lamivudine monotherapy or combination of peginterferon and lamivudine had liver biopsy at the end of 1 year therapy and were followed for 52 more weeks after cessation of therapy. Serum HBV DNA, intrahepatic HBV ccc DNA, and total HBV DNA levels were determined. RESULTS: Forty-seven patients, including 34 males and 13 females, were studied. Twenty-seven patients received combination therapy, and 20 patients received lamivudine monotherapy. Twenty-nine patients had end-of-treatment virologic response, and 15 patients had sustained response 52 weeks after therapy. At the end of treatment, log serum HBV DNA levels correlated well with log intrahepatic HBV cccDNA and log intrahepatic total HBV DNA levels. Log intrahepatic cccDNA and log intrahepatic total DNA levels were significantly lower among patients with sustained virologic response. The adjusted odds ratio for log cccDNA was 5.3 (95% CI: 1.5-18.2, P = .009) and, for log intrahepatic HBV DNA, was 4.4 (95% CI: 1.3-14.7, P = .015) to predict sustained virologic response. Using log cccDNA at -0.80 copies/genome equivalent as cutoff, the sensitivity, specificity, and positive and negative predictive values and accuracy of predicting sustained virologic response were 73%, 78%, 56%, 86%, and 77% respectively. CONCLUSIONS: Intrahepatic HBV cccDNA and intrahepatic total HBV DNA levels at the end of therapy are superior to serum HBV DNA as surrogates of sustained virologic response.

Identification of chronic hepatitis B patients without significant liver fibrosis by a simple noninvasive predictive model.

OBJECTIVE: Histological assessment of liver fibrosis is important in the management of chronic hepatitis B (CHB) infection but poorly accepted by patients because of its invasiveness. The aim of this study was to develop a noninvasive model to assess liver fibrosis in CHB patients using clinical and routine laboratory data. PATIENTS AND METHODS: This was a retrospective study on 235 treatment-naive viremic CHB patients. Univariate analysis of data from the training cohort (n = 150) followed by multivariate logistic regression were performed to identify independent predictors of significant fibrosis and generate predictive models. The models were validated with the remaining patients or validation cohort (n = 85) and by receiver operating characteristics (ROC) analysis. RESULTS: Body mass index (BMI), platelet count, serum albumin, and total bilirubin levels were identified as independent predictors of bridging fibrosis or cirrhosis (Ishak stage 3-6). ROC analysis was performed using the predictive probabilities derived from the regression models. The area under the ROC curve of the best model was 0.803 (95% CI: 0.729-0.878) for the training cohort, 0.765 (95% CI: 0.644-0.885) for the validation cohort, and 0.791 (95% CI: 0.728-0.854) for the entire cohort. Using the low cut-off probability of 0.15, significant fibrosis could be excluded in 83 patients of the total patient population (negative predictive value 0.92). CONCLUSIONS: Our noninvasive model comprising BMI and three routine laboratory tests was accurate in predicting absence of significant fibrosis. Application of this model could provide useful additional information on the stage of disease, guide future management decisions, and potentially decrease the need for liver biopsy in some CHB patients.

A randomized, controlled trial of combination therapy for chronic hepatitis B: comparing pegylated interferon-alpha2b and lamivudine with lamivudine alone.

BACKGROUND: Conventional interferon and lamivudine monotherapy are unsatisfactory in treating hepatitis B virus (HBV) infection. OBJECTIVE: To evaluate the efficacy and safety of pegylated interferon-alpha2b and lamivudine combination therapy for chronic hepatitis B. DESIGN: Randomized, controlled, open-label trial. SETTING: Outpatient clinic in a referral center. PARTICIPANTS: 100 treatment-naive patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B and moderately elevated alanine aminotransferase levels. MEASUREMENT: The primary end point was sustained virologic response (HBeAg seroconversion and HBV DNA level < 500,000 copies/mL) at 24 weeks after cessation of treatment. INTERVENTION: A staggered regimen of combination therapy with pegylated interferon-alpha2b (1.5 microg/kg of body weight per week; maximum, 100 microg) given for 32 weeks plus lamivudine (100 mg daily) given for 52 weeks versus lamivudine (100 mg daily) monotherapy given for 52 weeks. Of the 100 participants, 96% completed treatment and 80% completed post-treatment follow-up. RESULTS: The rate of sustained virologic response was 36% for the combination treatment group and 14% for the lamivudine monotherapy group (absolute difference, 22 percentage points [95% CI, 6 to 38 percentage points]). End-of-treatment outcomes showed that, compared with monotherapy, patients receiving combination therapy more often had virologic response (60% vs. 28% [absolute difference, 32 percentage points (CI, 14 to 50 percentage points)]); had more substantial reductions of HBV DNA (3.91 log10 copies/mL vs. 2.83 log10 copies/mL); and less often had lamivudine-resistant mutants (21% vs. 40%). The percentages of patients with normalization of alanine aminotransferase levels and histologic improvement did not differ. Adverse effects, such as transient influenza-like symptoms, alopecia, and local erythematous reactions, were more common with combination therapy. LIMITATIONS: This study lacked a double-blind design and was conducted at 1 institution. Because of the staggered pegylated interferon-lamivudine regimen, patients assigned to combination therapy received treatment for 8 weeks longer than those assigned to monotherapy. CONCLUSIONS: In patients with HBeAg-positive chronic hepatitis B, staggered combination treatment with pegylated interferon-alpha2b and lamivudine may lead to a higher rate of virologic response than lamivudine monotherapy.

Developmental regulation and cellular distribution of human cytosolic malate dehydrogenase (MDH1).

Human cyotsolic malate dehydrogenase (MDH1) is important in transporting NADH equivalents across the mitochondrial membrane, controlling tricarboxylic acid (TCA) cycle pool size and providing contractile function. Cellular localization studies indicate that MDH1 mRNA expression has a strong tissue-specific distribution, being expressed primarily in cardiac and skeletal muscle and in the brain, at intermediate levels in the spleen, kidney, intestine, liver, and testes and at low levels in lung and bone marrow. The observed MDH1 localizations reflect the role of NADH in the support of a variety of functions in different organs. These functions are primarily related to aerobic energy production for muscle contraction, neuronal signal transmission, absorption/resorption functions, collagen-supporting functions, phagocytosis of dead cells, and processes related to gas exchange and cell division. During neonatal development, MDH1 is expressed in human embryonic heart as early as the 3rd month and then is over-expressed from the 5th month until the birth. The expression of MDH1 is maintained in the adult heart but is not present in levels as high as in the fetus. Finally, over-expression of MDH1 is found in left ventricular cardiac muscle of dilated cardiomyopathy (DCM) patients when contrasted to the diseased non-DCM and normal heart muscle by in situ hybridization and Western blot. These observations are compatible with the activation of glucose oxidation in relatively hypoxic environments of fetal and hypertrophied myocardium.

[Hypermethylation of Ras association domain family protein 1A, hypermethylated in cancer 1 and p73 genes in hepatocellular carcinoma].

OBJECTIVE: To evaluate the status of promoter hypermethylation of Ras association domain family protein 1A (RASSF1A), hypermethylated in cancer 1 (HIC1) and p73 genes in hepatocellular carcinoma (HCC) and to explore the correlation with clinicopathological features. METHODS: Forty cases of HCC and their corresponding non-tumor liver tissues, other 2 cases of healthy donor livers were detected using methylation specific polymorphism chain reaction (MSP) method. RESULTS: The frequency of promoter hypermethylation of RASSF1A showed 90.0% and 72.5% in tumor and corresponding non-tumor tissues respectively, and there was significant difference between them (P < 0.05). The frequency of promoter hypermethylation of HIC1 showed 77.5% and 70.0% in tumor and corresponding non-tumor tissues respectively. The frequency of hypermethylation of HIC1 in non-tumor liver tissues showed significant correlation between younger and older patients. The frequency of promoter hypermethylation of p73 showed 5.0% in tumor tissues. However, none of hypermethylation of the gene was detected in corresponding non-tumor liver tissues. There was none of hypermethylation of the three genes showed in two cases of healthy donor livers. CONCLUSION: Promoter hypermethylation of RASSF1A and HIC1 genes are common event in HCC and play an important role in the pathogenesis and may be used to develop novel diagnostic and therapeutic approaches for HCC in the future.

Nuclear telomerase is less accessible to antibody probing than known nuclear antigens: retrieval with new immunostaining buffer.

Telomerase is an important tumor marker but few antibodies to the enzyme have been described or used without difficulty in histochemical detection. Here we report specific detection of the enzyme in cell and tissue preparations using a new monoclonal antibody (mAb 476) and a new antigen-retrieval buffer (Enhancing buffer). When used to detect telomerase under normal immunostaining conditions in HL-60 cells or tissue sections of hepatocellular carcinoma or metastatic choriocarcinoma, unexpectedly, the antibody stained the cytoplasm rather than the nucleus. Nuclear staining, however, was revealed using the Enhancing buffer. Since other nuclear antigens in the HL-60 cell could be stained both ordinarily and in the Enhancing buffer, nuclear telomerase appears to be shrouded by the nuclear matrix or blocked by accessory proteins. The cytoplasmic activity seen in normal buffer but absent largely from the Enhancing buffer may be an artifact or the nascent, "naked" enzyme. With a known cytoplasmic antigen (proteinase-3) chosen arbitrarily for comparison, the antigenicity was found enhanced, instead, by the Enhancing buffer. The mode of action of the Enhancing buffer differs from that of microwave irradiation or the signal amplification (CSA) used by some investigators. The latter was found to enhance the cytoplasmic reactivity rather than the nuclear reactivity of mAb 476.

BRE enhances in vivo growth of tumor cells.

Human BRE, a death receptor-associating intracellular protein, attenuates apoptotic response of human and mouse tumor cell lines to death receptor stimuli in vitro. In this report, we addressed whether the in vitro antiapoptotic effect of BRE could impact on tumor growth in vivo. We have shown that the mouse Lewis lung carcinoma D122 stable transfectants of human BRE expression vector developed into local tumor significantly faster than the stable transfectants of empty vector and parental D122, in both the syngeneic C57BL/6 host and nude mice. In vitro growth of the BRE stable transfectants was, however, not accelerated. No significant difference in metastasis between the transfectants and the parental D122 was detected. Thus, overexpression of BRE promotes local tumor growth but not metastasis. We conclude that the enhanced tumor growth is more likely due to the antiapoptotic activity of BRE than any direct effect of the protein on cell proliferation.

Quantitative assessment of fibrosis in liver biopsies from patients with chronic hepatitis B.

BACKGROUND/AIM: Accurate histological assessment of liver fibrosis is essential in the management of chronic hepatitis B (CHB). Although semi-quantitative scoring systems describe well the pathological patterns of hepatic structure, they produce fibrosis evaluation that is not very precise. Image analysis or morphometry has the theoretical advantage of providing truly quantitative data. PATIENTS AND METHODS: The present study aimed at validating a new image analysis system, Bioquant Nova Prime, in estimating collagen content in liver biopsy samples from patients with CHB. The biopsies were stained with picrosirius red and the areas of collagen were measured. The results were correlated with laboratory parameters and Ishak modified histological scores. Discriminative reliability of morphometry was determined using receiver operating characteristics (ROC) analysis. RESULTS: There was excellent interobserver agreement (r=0.84-0.94, P<0.01) in the morphometric analysis. Significant correlations between the quantitative morphometric data and the semi-quantitative score (Spearman's r=0.68-0.78, P<0.001) were also demonstrated. Excellent discriminative power of morphometry in differentiating mild from advanced fibrosis and cirrhosis from absence of cirrhosis was shown by the ROC analysis. CONCLUSIONS: Our results validated the use of Bioquant Nova Prime in estimating collagen content in liver biopsies. We showed that morphometry is a sensitive method of liver fibrosis quantification in CHB and complements semi-quantitative histological scoring system. This tool, with its reliable intraassay variability, could be of special value in assessing histological response to treatment after anti-viral or anti-fibrotic therapy.

[Methylation of mismatch repair gene (MMR) in primary hepatocellular carcinoma].

OBJECTIVE: To assess the role of methylated mismatch repair (MMR) genes (hMLH1, hMSH2 and hMSH3) in the carcinogenesis and progression of hepatocellular carcinoma (HCC). METHODS: Samples of 38 cases of HCC along with their corresponding noncancerous tissues, 2 samples of donated normal tissue and 6 cell lines were collected and subject to the methylation-specific PCR (MSP) to examine promoter methylation status of MLH1, MSH2 and MSH3. Six tumor cell lines were analyzed before and after 5-aza-2'-deoxycytidine treatment. In addition, alterations of mRNA expression of MMRs were investigated by quantitative reverse transcription-PCR. RESULTS: CpG island methylation of hMLH1 and hMSH2 was observed in 13.2% (5 of 38 samples) and 68.4% (26 of 38 samples) respectively in HCC, 2.6% (1 of 38 samples) and 55.3% (21 of 38) respectively in corresponding noncancerous tissues, but not in normal control tissues. Promoter methylation of the hMSH2 gene was present in 83.3% of cell lines tested (5/6), but none were observed for the hMLH1 gene. Promoter methylation of the hMSH3 gene was not identified in any tissue samples or cell lines. After 5-aza-2'-deoxycytidine treatment, hMSH2 methylation was induced or completely reversed, and its mRNA expression was increased in most cell lines. CONCLUSIONS: Our results suggest that promoter hypermethylation of hMLH1 and hMSH2 genes is common in HCC. Particularly, there is a high frequency of methylation of hMSH2 in both cancer and noncancerous tissues, but not in normal control tissue. Therefore, hypermethylation of MMR genes, especially hMSH2, may be involved in the carcinogenesis of HCC and may serve as an early diagnostic marker for HCC. The close correlation between hMSH2 methylation and low expression of its mRNA suggests that hMSH2 methylation is an important pathway in the regulation of gene expression.

Salvage surgery following downstaging of unresectable hepatocellular carcinoma.

OBJECTIVE: We reported here a series of 49 patients with unresectable hepatocellular carcinoma (HCC) who underwent nonsurgical treatment to downstage the disease followed by salvage surgery, their long-term outcome, and pattern of recurrence. SUMMARY BACKGROUND DATA: Most HCC patients present with unresectable disease and are treated with chemotherapy or intra-arterial therapy with a palliative intent. Occasionally, there are good responses to treatment so that salvage surgery becomes feasible afterward. However, long-term outcomes of these patients are seldom reported. METHODS: Patients with unresectable hepatocellular carcinoma, from September 1993 to June 2002, who received salvage surgery after downstaging by systemic chemotherapy, intra-arterial yttrium-90 microspheres, or sequential treatment were included in this study. Systemic chemotherapy consisted of combination doxorubicin, cisplatin, interferon-alpha and 5-fluorouracil (5-FU), or single-agent doxorubicin. The choice of treatment was according to stage of disease and contemporary clinical trial protocol. Survival, recurrence pattern, and surgical outcome were studied. RESULTS: There were 49 patients in this study with 40 males and 9 females, age ranged from 12 to 69 years. Forty patients (81.6%) were hepatitis B positive. Thirty-two patients had combination chemotherapy alone (65.3%), 8 patients had single agent chemotherapy alone (16.3%), 4 patients received intra-arterial yttrium-90 microspheres alone (8.2%), and 5 patients received sequential therapy (10.2%). Twenty-eight (57.1%) patients received major hepatic resection. Thirteen patients (26.5%) had complete necrosis of the tumor after treatment. Twenty-one patients (42.9%) had recurrence after surgery, and 14 of them were intrahepatic recurrence. The median survival was 85.9 months. The 1-year, 3-year, and 5-year survival rates were 98%, 64%, and 57%, respectively. CONCLUSIONS: Salvage surgery after successful downstaging can provide long-term control of disease in a small proportion of patients with unresectable hepatocellular carcinoma.

Does percutaneous liver biopsy of hepatocellular carcinoma cause hematogenous dissemination? An in vivo study with quantitative assay of circulating tumor DNA using methylation-specific real-time polymerase chain reaction.

OBJECTIVE: Our purpose was to find out whether percutaneous biopsy of hepatocellular carcinoma will cause significant dissemination of tumor into the circulation by quantitative analysis of circulating tumor DNA. SUBJECTS AND METHODS: In this prospective study of 32 patients with suspected hepatocellular carcinoma who underwent sonographically guided liver biopsy, a peripheral venous blood sample was obtained before and 5 min after the procedure. Biopsy was performed using an 18-gauge biopsy gun. DNA was extracted from the plasma of the blood samples for methylation-specific polymerase chain reaction. Quantitative measures of the plasma tumor DNA were determined with real-time quantitative polymerase chain reaction, and the amount was expressed as a methylation index (%) in plasma. RESULTS: Nineteen (59.4%) of 32 patients did not have detectable p16 tumor suppressor gene marker (p16M) in plasma before biopsy, and they showed no detectable plasma p16M after biopsy. Thirteen (65%) of 20 patients had p16M identified in the plasma before liver biopsy. Quantitative analysis of the plasma tumor DNA in these 13 patients showed no statistically significant difference in the methylation index before and after biopsy (p = 0.345, Wilcoxon's signed rank test). CONCLUSION: No evidence exists that percutaneous liver biopsy results in hematogenous dissemination of hepatocellular carcinoma as shown by quantitative analysis of circulating tumor DNA (p16M) using methylation-specific real-time polymerase chain reaction.

Nuclear matrix protein expressions in hepatocytes of normal and cirrhotic rat livers under normal and regenerating conditions.

We explored the feasibility of studying nuclear matrix protein (NMP) expressions of the hepatocytes in normal and cirrhotic rat livers with liver regeneration after partial hepatectomy. Sixteen Wistar healthy rats were studied with experimental liver regeneration and/or liver cirrhosis. Two-dimensional (2-D) gel electrophoresis was used to generate these NMP compositions from these rat liver samples. Several antibodies against cytokeratin, vimentin, actin, B23, HNF4alpha, and heat shock protein 70 were used for identification by Western blot. Totally, 41 strongly stained protein spots were characterized on the 2-D gels. Thirty-four protein spots were detected in all of these rat livers, of which, cytokeratin, vimentin, actin, HNF4alpha, and heat shock protein 70 were identified. B23 was detected in the regenerated livers. Three protein spots (s33, s34, and s35) were detectable only in NMP preparation extracted from the regenerating rat livers after hepatectomy. Another three protein spots (s36, s37, and s38) were detectable only in NMP preparation extracted from thioacetamide-induced cirrhotic rat livers. Under these conditions including experimental liver regeneration and/or liver cirrhosis, Over thirty higher abundance NMPs of hepatocytes were consistently expressed and considered as common and basic NMPs. Some of the NMPs are specific for liver regeneration and may play a critical role in cell proliferation and cell cycle, and some are specific for liver cirrhosis.

Nucleophosmin/B23 is a proliferate shuttle protein associated with nuclear matrix.

It has become obvious that a better understanding and potential elucidation of the nucleolar phosphoprotein B23 involving in functional interrelationship between nuclear organization and gene expression. In present study, protein B23 expression were investigated in the regenerative hepatocytes at different periods (at days 0, 1, 2, 3, 4, 7) during liver regeneration after partial hepatectomy on the rats with immunohistochemistry and Western blot analysis. Another experiment was done with immunolabeling methods and two-dimensional (2-D) gel electrophoresis for identification of B23 in the regenerating hepatocytes and HepG2 cells (hepatoblastoma cell line) after sequential extraction with detergents, nuclease, and salt. The results showed that its expression in the hepatocytes had a locative move and quantitative change during the process of liver regeneration post-operation. Its immunochemical localization in the hepatocytes during the process showed that it moved from nucleoli of the hepatocytes in the stationary stage to nucleoplasm, cytoplasm, mitotic spindles, and mitotic chromosomes of the hepatocytes in the regenerating livers. It was quantitatively increased progressively to peak level at day 3 post-operation and declined gradually to normal level at day 7. It was detected in nuclear matrix protein (NMP) composition extracted from the regenerating hepatocytes and HepG2 cells and identified with isoelectric point (pI) value of 5.1 and molecular weight of 40 kDa. These results indicated that B23 was a proliferate shuttle protein involving in cell cycle and cell proliferation associated with nuclear matrix.

Positional mapping for amplified DNA sequences on 1q21-q22 in hepatocellular carcinoma indicates candidate genes over-expression.

BACKGROUND/AIMS: Comparative genomic hybridization analysis on hepatocellular carcinoma (HCC) indicated frequent gains of 1q and an amplicon at 1q21-q22. Current cytogenetic evidences confer much importance on 1q21-q22, where a role in drug resistance, tumor metastasis and shorter patient survival had been implicated. METHODS: Using positional mapping by interphase cytogenetics, we investigated the amplicon 1q21-q22 in five HCC cases. Three amplification maxima represented by yeast artificial chromosomes (YACs) 955E11, 876B11 and 945D5 that mapped to regions 1q21.1, 1q21.2 and 1q22, respectively, were indicated. We further investigated candidate genes expression in the mapped YACs by quantitative reverse-transcription-polymerase chain reaction. A panel of genes encoding protein transcripts involved in apoptosis, cell cycle progression, calcium binding and jumping translocation was studied. RESULTS: Among ten HCC cases with the amplicon 1q21-q22 examined, we found a significant gene expression level of JTB, SHC1, CCT3 and COPA in the tumors than the paired adjacent non-malignant liver tissues (P< or =0.04). CONCLUSIONS: Our interphase findings on 1q21-q22 pinpointed three affected loci between D1S305 and D1S2369. Up-regulation of candidate genes identified within these over-represented regions may represent targets in the progression of HCC and may carry prognostic significance.

Identification of four distinct regions of allelic imbalances on chromosome 1 by the combined comparative genomic hybridization and microsatellite analysis on hepatocellular carcinoma.

Frequent chromosome 1 abnormalities detected in human hepatocellular carcinoma have been implicated in early genetic events of liver carcinogenesis. Recurrent loss of 1p with a common deleted region 1p36-p34 has been reported from microsatellite analysis, whereas common gain of the whole chromosome q-arm was described from several comparative genomic hybridization studies. The relationships between copy number changes and allelic status however remains unclear. In this study, we have conducted a simultaneous comparative genomic hybridization and microsatellite analysis study on chromosome 1 in 31 hepatocellular carcinoma cases. Microsatellite analysis revealed frequent loss of heterozygosity on 1p at loci D1S468 (74%), D1S450 (67%), D1S2667 (65%), D1S2697 (75%), D1S199 (52%), and D1S234 (67%) corresponded to the distal 1p36 region and coincided with 12 cases (86%) that presented losses on 1p by comparative genomic hybridization analysis. Although comparative genomic hybridization indicated a common deleted region of 1p36-p35 in the current series, microsatellite analysis has refined the smallest overlapping region (SOR) to 1p36.13-p36.22. Gain of 1q as revealed by comparative genomic hybridization suggested low and high-level gains, and cases that displayed an amplicon below the heterochromatic region 1q21-q25. Common allelic imbalances of polymorphic markers D1S2635 (64%), D1S484 (67%), D1S2878 (65%), D1S196 (70%), D1S249 (64%) D1S2785 (75%), D1S2842 (73%) and D1S2836 (74%) that corresponded to the regions 1q23.1-q24.2, 1q32.1 and 1q43-q44 were detected. Three distinct regions of allelic imbalances were thus suggested on recurring 1q gain found in hepatocellular carcinoma. Furthermore, microsatellite analysis has enabled a mapping of common overrepresented regions and suggested SOR on 1q23.1-q23.3 (D1S2635-D1S2878), 1q25.1-q31.1 (D1S452-D1S238), and 1q43 (D1S2785-D1S2842). Our current study has refined chromosome 1 aberrations in hepatocellular carcinoma to four regions of allelic imbalances. The SORs delineated should provide basis for further molecular investigation in hepatocarcinogenesis on genes residing on these chromosomal regions.