Stathmin1 overexpression associated with polyploidy, tumor-cell invasion, early recurrence, and poor prognosis in human hepatoma

Frequent intrahepatic metastasis causes early tumor recurrence and dismaying prognosis of human hepatocellular carcinoma (HCC). We recently identified overexpression of stathmin1 (STMN1) in human HCC. This study was designed to elucidate the clinical and biological significance of overexpression of STMN1 in HCC. Expression of STMN1 was conducted by quantitative reverse transcription-polymerase chain reaction and immunoblotting assays on 58 pairs of HCC and para-tumor liver tissues from patients with HCC along with normal liver tissues as the controls. Association of STMN1 overexpression with tumor recurrence and prognosis was investigated by Kaplan-Meier cumulative survival and Cox Regression analyses. Roles of STMN1 in cell cycle, cell motility, and invasion were determined by in vitro assays. STMN1 overexpression in hepatoma was strongly associated with local invasion (P = 0.031), early recurrence (P = 0.002), and poor prognosis (P = 0.005), and was an independent indicator for tumor recurrence (P = 0.0045). STMN1 overexpression further identified subgroups of HCC patients with higher tumor recurrence and worse prognosis among HCC patients with early tumor stage (T1) or intermediate histological grades (G2 and G3), both of whom represent the majority of HCC patients receiving primary curative hepatectomy. Silencing STMN1 expression via RNA interference suppressed invasion activity, while ectopic expression of STMN1 enhanced cell invasion and caused polyploidy of cells. In conclusion, STMN1 overexpression could predict early tumor recurrence and poor prognosis, particularly at early stage of hepatoma. Overexpression of STMN1 promoted polyploidy formation, tumor-cell invasion, and intrahepatic metastasis, suggesting that STMN1 can be a target for anti-cancer therapy of human hepatoma.

Deficiency of glycine N-methyltransferase results in deterioration of cellular defense to stress in mouse liver

PURPOSE

Previously, we reported that glycine N-methyltransferase (GNMT) interacts with benzo[a]pyrene (BaP) and inhibits BaP-DNA adducts formation. In addition, Gnmt knockout (Gnmt(-/-)) mice developed chronic hepatitis and hepatocellular carcinoma (HCC). The aims of this study were to understand the gene expression profile of Gnmt(-/-) mice and to study the interaction between BaP and GNMT deficiency in vivo.

EXPERIMENTAL DESIGN

Gene expression profiles of Gnmt(-/-) mice were analyzed by 2-D PAGE and real-time PCR. Both wild-type and Gnmt(-/-) mice were challenged with BaP and sacrificed at the age of 13 months.

RESULTS

Compared with the wild-type mice, proteins involved in the anti-oxidation/detoxification response, glycolytic energy metabolism and one-carbon metabolism pathways were down-regulated significantly in Gnmt(-/-) mice. Malondialdehyde assay showed that lipid peroxidation was significantly increased in the Gnmt(-/-) mice liver. H(2)O(2) treatment demonstrated that the survival rate of HuH-7 cells overexpressing GNMT was significantly higher than the controls. BaP challenge experiments showed that 71.4% (5/7) of male and all (7/7) female Gnmt(-/-) mice developed HCC, while only 16.7% (1/6) of male and 20% (1/5) of female wild-type mice had HCC.

CONCLUSION AND CLINICAL RELEVANCE

GNMT regulates genes related to detoxification and anti-oxidation pathways. BaP is a liver cancer carcinogen especially during GNMT deficiency.

Sirolimus-induced signaling modifications in Kaposi's sarcoma with resolution in a liver transplant recipient

Sirolimus is one treatment option in transplant recipients with Kaposi's sarcoma (KS), which involves dysregulation of Akt-mammalian target of rapamycin (mTOR) signaling pathway. Signal modifications after sirolimus therapy in organ recipients with KS are largely unknown and not verified. We reported a case of KS found two yr after liver transplantation in which the immunosuppression was changed from tacrolimus, MMF, and steroid to sirolimus alone. In skin, which was found to have persistent KS after a two-month treatment of sirolimus and was removed completely one yr later, KS was no longer present. The patient went well without graft rejection. Tumor biopsies were performed before, two months, and one yr after the start of sirolimus. Immunohistochemical staining of vascular endothelial growth factor (VEGF), p-Akt, p-mTOR, p-p70 S6 kinase, and Western blot for p-tuberin/ tuberous sclerosis complex (TSC)2 was performed. VEGF was suppressed thoroughly in two-month use of sirolimus. In addition, p-Akt and p-mTOR, which were decreased at two months, could not be detected after one yr of treatment. Moreover, p-p70 S6 kinase, expressed strongly in overlying epidermis initially, was suppressed completely after two months of treatment. However, p-tuberin/TSC2, contrary to suggested theoretically, was not detected through all specimens, implying not to be a significant event. Suppressed expression of VEGF, p-Akt, and p-mTOR was the major event of signaling modification through the long-term use of sirolimus.

Identification of nonsense mutations in hepatitis B virus S gene in patients with hepatocellular carcinoma developed after lamivudine therapy

Background

Lamivudine is widely used in patients with chronic hepatitis B virus (HBV) infection. In cirrhotic patients, long-term lamivudine therapy significantly reduced the risk of hepatocellular carcinoma (HCC). However, in a small but substantial portion of patients, HCC still developed despite lamivudine therapy. Prolonged usage of lamivudine led to mutations in the polymerase gene, where concurrent nonsense mutations in the HBV S gene occasionally occurred. The significance of such mutations in hepatocarcinogenesis remains elusive. Here, we aimed to understand the oncogenicity of HBV pre-S/S nonsense mutations identified in patients with HCC that developed after lamivudine therapy.

Methods

Of 141 consecutive hepatitis B surface antigen-positive HCC patients, 8 developed HCC after receiving lamivudine therapy. The HBV pre-S/S sequences in their serum and tissue samples were analysed. A sex-and age-matched group of HCC patients who never received lamivudine therapy were included as controls. Site- directed mutagenesis experiments were performed to generate identified pre-S/S nonsense mutations in expression vectors for tumourigenicity analysis.

Results

Seven of eight patients in the lamivudine-treated group harboured nonsense mutations in the S gene compared with none in the control group ( P<0.001). Site- directed mutagenesis and transient transfection experiments revealed that these mutants could transactivate oncogene promoters. NIH3T3 cells stably expressing sL21*, sW156* and sW172* pre-S/S mutants had increased tumourigenicity in nude mice.

Conclusions

HCCs developed in lamivudine-treated patients who frequently carried nonsense mutations in the S gene. Such pre-S/S mutants are potentially oncogenic and might counteract the effect of lamivudine in preventing hepatocarcinogenesis.

Expression of the HCRP1 mRNA in HCC as an independent predictor of disease-free survival after surgical resection

AIM

Hepatocellular carcinoma (HCC)-related protein-1 (HCRP1) gene was located at chromosome 8p22, a frequently deleted region in HCC. The gene product was a subunit of mammalian Endosomal Sorting Complex Required for Transport (ESCRT)-I, essential for degradation of epidermal growth factor receptors. In this study, we examined the prognostic role of HCRP1 mRNA expression in HCC.

METHODS

The expression of HCRP1 mRNA in HCC was assessed in 125 patients receiving surgical resection of HCC. Using the adjacent non-cancerous tissues as a reference, 55 and 70 patients expressing high and low levels of HCRP1 mRNA, respectively, were identified. The predictive value of HCRP1 mRNA expression in postoperative survival was evaluated.

RESULTS

Expression of HCRP1 mRNA was not associated with any of the baseline clinicopathological parameters. However, univariate analysis showed that it was associated with a better disease-free survival (P < 0.001) and overall survival (P = 0.032). Stepwise Cox multivariate proportional hazards regression analysis showed that the expression of HCRP1 mRNA (hazard ratio [HR], 0.396; 95% confidence interval (CI), 0.233-0.674; P = 0.001), tumor number (HR, 1.596; 95% CI, 1.221-2.087; P = 0.001), serum aspartate aminotransferase (HR, 1.002; 95% CI, 1.000-1.003; P = 0.031) and the presence of microvascular invasion (HR, 1.852; 95% CI, 1.131-3.032; P = 0.014) were included as independent predictors for disease-free survival.

CONCLUSION

Expression of HCRP1 mRNA served as an independent predictor for postoperative disease-free survival in HCC patients.

Prenatal tolerance induction: relationship between cell dose, marrow T-cells, chimerism, and tolerance

It was reported that the dose of self-antigens can determine the consequence of deletional tolerance and donor T cells are critical for tolerance induction in mixed chimeras. This study aimed at assessing the effect of cell doses and marrow T cells on engraftment and tolerance induction after prenatal bone marrow transplantation. Intraperitoneal cell transplantation was performed in FVB/N (H-2K(q)) mice at gestational day 14 with escalating doses of adult C57BL/6 (H-2K(b)) marrows. Peripheral chimerism was examined postnatally by flow cytometry and tolerance was tested by skin transplantation. Transplantation of light-density marrow cells showed a dose response. High-level chimerism emerged with a threshold dose of 5.0 x 10(6) and host leukocytes could be nearly replaced at a dose of 7.5-10.0 x 10(6). High-dose transplants conferred a steady long-lasting donor-specific tolerance but were accompanied by >50% incidence of graft-versus-host disease. Depletion of marrow T cells lessened graft-versus-host disease to the detriment of engraftment. With low-level chimerism, tolerance was a graded phenomenon dependent upon the level of chimerism. Durable chimerism within 6 months required a threshold of > or = 2% chimerism at 1 month of age and predicted a 50% chance of long-term tolerance, whereas transient chimerism (<2%) only caused hyporesponsiveness to the donor. Tolerance induction did not succeed without peripheral chimerism even if a large amount of injected donor cells persisted in the peritoneum. Neither did an increase in cell doses or donor T-cell contents benefit skin graft survivals unless it had substantially improved peripheral chimerism. Thus, peripheral chimerism level can be a simple and straightforward test to predict the degree of prenatal immune tolerance.

Characterization of a glycine N-methyltransferase gene knockout mouse model for hepatocellular carcinoma: Implications of the gender disparity in liver cancer susceptibility

Hepatocellular carcinoma (HCC) is the fifth common cancer in the world and it mainly occurs in men. Glycine N-methyltransferase (GNMT) participates in one-carbon metabolism and affects DNA methylation by regulating the ratio of S-adenosylmethionine to S-adenosylhomocystine. Previously, we described that the expression of GNMT was diminished in human HCC. Here, we showed that 50% (3/6) male and 100% (7/7) female Gnmt-/- mice developed HCC, and their mean ages of HCC development were 17 and 16.5 months, respectively. In addition, 42.9% (3/7) of female Gnmt-/- mice had hemangioma. Wnt reporter assay demonstrated that Gnmt is a negative regulator for canonical Wnt signaling pathway. Beta-catenin, cyclin D1 and c-Myc, genes related to Wnt pathway, were upregulated in the liver tissues from both 11 weeks and HCC stage of Gnmt-/- mice. Furthermore, global DNA hypomethylation and aberrant expression of DNA methyltransferases 1 and 3b were found in the early and late stages of HCC development. Hierarchical cluster analysis of 6,023 transcripts from microarray data found that gene expression patterns of HCC tumors from male and female Gnmt-/- mice were distinctively different. Real-time PCR confirmed that Gadd45a, Pak1, Mapk3 and Dsup3 genes of mitogen-activated protein kinase (MAPK) pathway were activated in Gnmt-/- mice, especially in the female mice. Therefore, GNMT is a tumor suppressor gene for liver cancer, and it is associated with gender disparity in liver cancer susceptibility.

Reversed mutation rates of KRAS and EGFR genes in adenocarcinoma of the lung in Taiwan and their implications

BACKGROUND

In western countries, the Kirsten ras oncogene homolog gene (KRAS) mutation rate is high in patients with nonsmall cell lung cancer (NSCLC), especially in those with adenocarcinoma (30%-50%), but the epidermal growth factor receptor gene (EGFR) mutation rate is very low (3%-8%). In addition, KRAS mutations reportedly were associated with EGFR tyrosine kinase inhibitor (EGFR-TKI) resistance. In Taiwan, high EGFR mutation rates associated with high EGFR-TKI response rates in patients with NSCLC have been reported; however, KRAS mutation data are limited and have not been correlated with TKI response.

METHODS

KRAS mutation analysis was performed on 237 NSCLC specimens, and the results were correlated with clinicopathologic features. All but 2 tumors also underwent EGFR mutation analysis.

RESULTS

KRAS mutations were identified in only 9 of 237 patients (3.80%). Five patients were women who were nonsmokers, and 4 patients were men who were ever-smokers. The mutation rate was 5.03% in patients with adenocarcinoma (8 of 159 patients) and 1.56% in patients with squamous cell carcinoma (1 of 64 patients). Four mutations were G12V, 3 mutations were G12D, 1 mutation was L19F, and 1 was the duplication insertion mutation dupT50_M72. In contrast, EGFR mutations were detected in 96 of 235 patients (40.8%) and in 90 of 157 adenocarcinomas (57.3%). None of the KRAS mutations coexisted with EGFR mutations. KRAS mutations were not associated significantly with any clinicopathologic characteristics, including smoking status. Among the 53 patients who had received TKI monotreatment, only 1 patient had a KRAS mutation and had progressive disease.

CONCLUSIONS

The KRAS mutation rate was too low to play a significant role in TKI resistance or tumorigenesis among Taiwanese patients with NSCLC, which was the complete reverse of the results reported in western countries.

Identification of nonsense mutations in hepatitis B virus S gene in patients with hepatocellular carcinoma developed after lamivudine therapy

BACKGROUND

Lamivudine is widely used in patients with chronic hepatitis B virus (HBV) infection. In cirrhotic patients, long-term lamivudine therapy significantly reduced the risk of hepatocellular carcinoma (HCC). However, in a small but substantial portion of patients, HCC still developed despite lamivudine therapy. Prolonged usage of lamivudine led to mutations in the polymerase gene, where concurrent nonsense mutations in the HBV S gene occasionally occurred. The significance of such mutations in hepatocarcinogenesis remains elusive. Here, we aimed to understand the oncogenicity of HBV pre-S/S nonsense mutations identified in patients with HCC that developed after lamivudine therapy.

METHODS

Of 141 consecutive hepatitis B surface antigen-positive HCC patients, 8 developed HCC after receiving lamivudine therapy. The HBV pre-S/S sequences in their serum and tissue samples were analysed. A sex- and age-matched group of HCC patients who never received lamivudine therapy were included as controls. Site-directed mutagenesis experiments were performed to generate identified pre-S/S nonsense mutations in expression vectors for tumourigenicity analysis.

RESULTS

Seven of eight patients in the lamivudine-treated group harboured nonsense mutations in the S gene compared with none in the control group (P<0.001). Site-directed mutagenesis and transient transfection experiments revealed that these mutants could transactivate oncogene promoters. NIH3T3 cells stably expressing sL21*, sW156* and sW172* pre-S/S mutants had increased tumourigenicity in nude mice.

CONCLUSIONS

HCCs developed in lamivudine-treated patients who frequently carried nonsense mutations in the S gene. Such pre-S/S mutants are potentially oncogenic and might counteract the effect of lamivudine in preventing hepatocarcinogenesis.

Sustained baculovirus-mediated expression in myogenic cells

BACKGROUND

Baculovirus has emerged as a promising gene delivery vector due to its low cytotoxicity and nonreplication nature in mammalian cells. However, baculovirus-mediated expression is transient and generally lasts less than 14 days, which could restrict its application in the treatment of diseases requiring stable transgene expression.

METHODS

We transduced myoblast cell lines C2C12, Sol 8 and primary myoblasts with a baculovirus expressing the enhanced green fluorescent protein (EGFP) under the control of cytomegalovirus immediate-early promoter and measured the transduction efficiency by flow cytometry. Myogenic differentiation was induced after transduction and the longevity of EGFP expression was monitored by fluorescence microscopy. The myogenic differentiation was confirmed by reverse transcription-polymerase chain reaction (RT-PCR). The persistence of the egfp DNA and transcripts was monitored by real-time PCR and quantitative real-time RT-PCR.

RESULTS

Baculovirus efficiently transduced C2C12, Sol 8 and the primary myoblasts. The transgene expression persisted for a prolonged period of time (at least 63 days) in the cells differentiating into myotubes, but was transient in HeLa cells (<7 days). The sustained expression paralleled the myogenic differentiation and stemmed from the intracellular persistence of egfp DNA and mRNA.

CONCLUSIONS

The transgene delivered by baculovirus persists in the myotubes and endows sustained expression, which is distinct from its rapid degradation and transient expression in other cell types. These findings justify the future use of baculovirus for muscle-based gene therapy.

Acute respiratory distress syndrome caused by leukemic infiltration of the lung

Respiratory distress syndrome resulting from leukemic pulmonary infiltrates is seldom diagnosed antemortem. Two 60- and 80-year-old women presented with general malaise, progressive shortness of breath, and hyperleukocytosis, which progressed to acute respiratory distress syndrome (ARDS) after admission. Acute leukemia with pulmonary infection was initially diagnosed, but subsequent examinations including open lung biopsy revealed leukemic pulmonary infiltrates without infection. In one case, the clinical condition and chest radiography improved initially after combination therapy with chemotherapy for leukemia and aggressive pulmonary support. However, new pulmonary infiltration on chest radiography and hypoxemia recurred, which was consistent with acute lysis pneumopathy. Despite aggressive treatment, both patients died due to rapidly deteriorating condition. Leukemic pulmonary involvement should be considered in acute leukemia patients with non-infectious diffusive lung infiltration, especially in acute leukemia with a high blast count.

Restrictive dermopathy: report of one case and the metabolic and post-mortem findings

Restrictive dermopathy is a rare and lethal autosomal recessive genodermatosis characterized by tight skin, typical dysmorphic face, generalized arthrogryposis and pulmonary hypoplasia. Infants with restrictive dermopathy have similar findings in skin biopsy, but other abnormalities are unremarkable. We report a male preterm infant with restrictive dermopathy. The post-mortem examination revealed hypoplasia of the thymus, and the metabolic study of the urine and blood disclosed generalized organic aciduria and low free carnitine level. These data imply that restrictive dermopathy is associated with certain degrees of metabolic disturbance. With increasing reports of restrictive dermopathy, the affected infants can be diagnosed earlier and accurately.

Dense packing of portal lymphocytes predicts favorable treatment outcome in hepatitis C

BACKGROUND/AIMS

To identify pre-therapeutic predictors of sustained virological response (SVR) in Taiwanese patients with chronic hepatitis C.

METHODOLOGY

One hundred and ninety-eight consecutive patients receiving interferon plus ribavirin combination therapy were included. Stepwise logistic regression model was performed to estimate the SVR on the presence of various pre-therapeutic clinical parameters.

RESULTS

The difference of alanine aminotransferase and aspartate aminotransferase levels (beta = 0.0080, P=0.0151), the presence of genotype 1b (beta = -1.9225, P<0.0001), the presence of dense packing of inflammatory cells in portal tract (beta = 1.5239, P=0.0354), age (beta = -0.0441, P=0.0179) and pre-therapeutic HCV-RNA concentration (beta = -0.0682, P=0.0411) were identified as independent predictors in the regression analysis. Patients with dense packing of inflammatory cells in portal tract (n=21) had significantly higher aspartate aminotransferase concentration, higher histology activity index, higher fibrosis score, and more histologically cirrhosis (P=0.032, 0.0001, 0.034, and 0.020, respectively). Paradoxically, they had a higher chance to achieve SVR (18/21 (85.7%) versus 99/177 (55.9%); P=0.017).

CONCLUSIONS

Dense packing of inflammatory cells in portal tract is an independent predictor of SVR to antiviral therapy in patients with chronic hepatitis C.

Acute expression of hepatitis C core protein in adult mouse liver: Mitochondrial stress and apoptosis

OBJECTIVE

In infection with hepatitis C virus (HCV), spontaneous clearance of the virus occurs in 30-40% of cases. By contrast, in chronic infection, this is rare. The basis for viral clearance in acute disease is unknown. Whereas cellular immune responses have been studied in detail, few data exist on the role of viral structural proteins, such as the core protein. The purpose of this study was to investigate the effects of core produced de novo within adult mouse hepatocytes by using a new transgenic mouse line in which expression of HCV core is regulated by tetracycline (tet-off).

MATERIAL AND METHODS

In this work, transgenic mice with conditional HCV core were created, to study the acute expression of HCV core protein in the context of the mature liver. The subcellular distribution of the core, hepatocellular oxidative stress and apoptosis were monitored.

RESULTS

Core protein is readily detectable and strongly associated with cytoplasmic lipid vesicles, endoplasmic reticulum and mitochondria. Mitochondrial oxidative stress was evidenced by a reduction in thioredoxin-2 (trx2). Concurrently, caspase-3 activity and TUNEL increased and, over time, the level of core protein in the liver declined.

CONCLUSIONS

Mice that are conditionally transgenic for HCV core protein, which is readily detected and morphologically associated with steatosis in individual hepatocytes, were developed. Acute expression of core protein causes mitochondrial stress, as demonstrated by a reduction in trx2 and in the apoptosis of core-positive hepatocytes. We speculate that these events could be involved in the clearance of virus during acute hepatitis C, by both reducing the burden of virus in the liver and effectively priming the immune response.

Decreased expression of UK114 is related to the differentiation status of human hepatocellular carcinoma

Previous studies have identified that the expression of UK114 is tissue specific and the protein has been found to be most abundant in liver and kidney. However, the expression of UK114 in human hepatocellular carcinoma and its relationship to differentiation and transformation of hepatocellular carcinoma have not been studied. In this study, the expression of UK114 in human hepatocellular carcinoma was examined by Northern and Western blot analyses. We found that UK114 was significantly down-regulated in most of hepatocellular carcinoma tissues compared with adjacent nontumor tissues (72.7%) at both mRNA and protein levels. We looked into the possibility that this decreased expression of UK114 in the hepatocellular carcinoma tissues may play a role in the differentiation or tumorigenicity of hepatocellular carcinoma. Immunohistochemical staining showed that the reduced expression of UK114 in hepatocellular carcinoma tissues was correlated with the tumor differentiation status as graded by the Edmondson-Steiner classification. On the other hand, overexpression of UK114 was not able to suppress the proliferation of human hepatoma cells and tumorigenicity in nude mice. These results suggest that UK114 does not seem to act as a tumor suppressor gene; however, it may useful as a biomarker that will assist in the grading of the differentiation status of hepatocellular carcinoma samples.

A cell-based high-throughput screen for epidermal growth factor receptor pathway inhibitors

Epidermal growth factor receptor (EGFR) is a valid drug target for development of target-based therapeutics against non-small-cell lung cancer. In this study, we established a high-throughput cell-based assay to screen for compounds that may inhibit EGFR activation and/or EGFR-mediated downstream signaling pathway. This drug screening platform is based on the characterization of an EGFR-transfected 32D cell line (32D-EGFR). The expression of EGFR in 32D cells allowed cell proliferation in the presence of either epidermal growth factor (EGF) or interleukin 3 (IL-3) and provided a system for both screening and counterscreening of EGFR pathway-inhibitory compounds. After the completion of primary and secondary screenings in which 32D-EGFR cells were grown under the stimulation of either EGF or IL-3, 9 of 20,000 compounds were found to selectively inhibit the EGF-dependent proliferation, but not the IL-3-dependent proliferation, of 32D-EGFR cells. Subsequent analysis showed that 3 compounds of the 9 initial hits directly inhibited the kinase activity of recombinant EGFR in vitro and the phosphorylation of EGFR in H1299 cells transfected with EGFR. Thus, this 32D-EGFR assay system provides a promising approach for identifying novel EGFR and EGFR signaling pathway inhibitors with potential antitumor activity.

MET amplification occurs with or without T790M mutations in EGFR mutant lung tumors with acquired resistance to gefitinib or erlotinib

In human lung adenocarcinomas harboring EGFR mutations, a second-site point mutation that substitutes methionine for threonine at position 790 (T790M) is associated with approximately half of cases of acquired resistance to the EGFR kinase inhibitors, gefitinib and erlotinib. To identify other potential mechanisms that contribute to disease progression, we used array-based comparative genomic hybridization (aCGH) to compare genomic profiles of EGFR mutant tumors from untreated patients with those from patients with acquired resistance. Among three loci demonstrating recurrent copy number alterations (CNAs) specific to the acquired resistance set, one contained the MET proto-oncogene. Collectively, analysis of tumor samples from multiple independent patient cohorts revealed that MET was amplified in tumors from 9 of 43 (21%) patients with acquired resistance but in only two tumors from 62 untreated patients (3%) (P = 0.007, Fisher's Exact test). Among 10 resistant tumors from the nine patients with MET amplification, 4 also harbored the EGFR(T790M) mutation. We also found that an existing EGFR mutant lung adenocarcinoma cell line, NCI-H820, harbors MET amplification in addition to a drug-sensitive EGFR mutation and the T790M change. Growth inhibition studies demonstrate that these cells are resistant to both erlotinib and an irreversible EGFR inhibitor (CL-387,785) but sensitive to a multikinase inhibitor (XL880) with potent activity against MET. Taken together, these data suggest that MET amplification occurs independently of EGFR(T790M) mutations and that MET may be a clinically relevant therapeutic target for some patients with acquired resistance to gefitinib or erlotinib.

Glycine N-methyltransferase-/- mice develop chronic hepatitis and glycogen storage disease in the liver

Glycine N-methyltransferase (GNMT) affects genetic stability by regulating DNA methylation and interacting with environmental carcinogens. To establish a Gnmt knockout mouse model, 2 lambda phage clones containing a mouse Gnmt genome were isolated. At 11 weeks of age, the Gnmt-/- mice had hepatomegaly, hypermethioninemia, and significantly higher levels of both serum alanine aminotransferase and hepatic S-adenosylmethionine. Such phenotypes mimic patients with congenital GNMT deficiencies. A real-time polymerase chain reaction analysis of 10 genes in the one-carbon metabolism pathway revealed that 5,10-methylenetetrahydrofolate reductase, S-adenosylhomocysteine hydrolase (Ahcy), and formiminotransferase cyclodeaminase (Ftcd) were significantly down-regulated in Gnmt-/- mice. This report demonstrates that GNMT regulates the expression of both Ftcd and Ahcy genes. Results from pathological examinations indicated that 57.1% (8 of 14) of the Gnmt-/- mice had glycogen storage disease (GSD) in their livers. Focal necrosis was observed in male Gnmt-/- livers, whereas degenerative changes were found in the intermediate zones of female Gnmt-/- livers. In addition, hypoglycemia, increased serum cholesterol, and significantly lower numbers of white blood cells, neutrophils, and monocytes were observed in the Gnmt-/- mice. A real-time polymerase chain reaction analysis of genes involved in the gluconeogenesis pathways revealed that the following genes were significantly down-regulated in Gnmt-/- mice: fructose 1,6-bisphosphatase, phosphoenolpyruvate carboxykinase, and glucose-6-phosphate transporter.

CONCLUSION

Because Gnmt-/- mice phenotypes mimic those of patients with GNMT deficiencies and share several characteristics with GSD Ib patients, we suggest that they are useful for studies of the pathogenesis of congenital GNMT deficiencies and the role of GNMT in GSD and liver tumorigenesis.

Erlotinib response of EGFR-mutant gefitinib-resistant non-small-cell lung cancer

PURPOSE

Failure to gefitinib is generally believed to be associated with cross-resistance to other epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKI). Here we report a case whose active EGFR-mutant NSCLC responded to erlotinib treatment.

PATIENT AND METHODS

Lung specimen was obtained during diagnostic procedures from a 41-year-old Taiwanese male smoker with adenocarcinoma. He received cisplatin-based chemotherapy following craniotomy to remove his brain metastasis. Tumor progressed in both lung and left adrenal gland. He underwent second-line docetaxel chemotherapy. Tumor progressed again 7 months later. He was subsequently treated with gefitinib 250mg QD. Complete regression of the lung tumor and partial response of the left adrenal gland mass was achieved. Nine months later, the left lower lobe lung tumor and left adrenal gland tumor progressed. A lung biopsy from the left lower lobe disclosed an adenocarcinoma which harbored an in-frame deletion in exon 19 (heterozygous delE746-A750) of EGFR without a second mutation such as T790M in exon 20. Subsequent erlotinib 150mg QD was administered. He experienced grade 1 skin rash, diarrhea and paronychia following erlotinib.

RESULTS

This patient achieved a partial response to erlotinib treatment. He remained on erlotinib for a total of 18 months until the left adrenal gland tumor progressed.

CONCLUSIONS

This case demonstrated that NSCLC bearing in-frame deletion in exon 19 of EGFR may respond to erlotinib treatment following gefitinib failure.

Lymphoepithelioma-like hepatocellular carcinoma

Lymphoepithelioma-like carcinomas (LELC) of the liver are rare. Only nine cases have been reported. All of them were considered to be cholangiocarcinoma and the majority were positive for Epstein-Barr virus (EBV) on EBER in situ hybridization. Here we report a case of hepatocellular carcinoma (HCC) mainly composed of LELC. The patient was a 56-year-old man with chronic hepatitis C virus (HCV) infection and cirrhosis. A right-side hepatectomy was performed to remove a 3-cm diameter tumor. Microscopically, the tumor was mainly composed of undifferentiated carcinoma with heavy lymphocytic infiltration, consistent with LELC. The tumor cells of the LELC component were focally positive for HePar 1, CK19 and CK7 and more diffusely positive (50% of tumor cells) for AE1/AE3 on immuno-histochemical study. EBER in situ hybridization was negative. This is the first confirmed case of HCC with an LELC component. In the available literature, all three cases of LELC of the liver that were negative for EBV were associated with chronic viral hepatitis and cirrhosis, suggesting a different carcinogenesis of EBV-positive LELC of the liver.

Microcalcification detection in 3-d breast ultrasound

The appearance of cluster of microcalcifications in mammography or sonography is an important indicator for malignancy. Microcalcifications are calcium deposits, which can be identified as tiny areas that are slightly brighter than surrounding tissue. Detection of mammographic microcalcification has been proposed in many studies. Since a microcalcification cluster is a three-dimensional (3-D) entity, its projection onto a two-dimensional (2-D) image results in a loss of spatial information and may also cause superimposition of individual calcifications within the cluster. This paper aims to use the 3-D ultrasound to determine microcalcifications. In each slice, the proposed method adopts the top-hat filter to find bright spots, and employs four 2-D criteria to select the spots as candidate microcalcifications. Finally, spots appearing in sequent slices at the same position are considered as a microcalcification. We suggest using a computer automatically to detect the microcalcification being feasible and microcalcifications being a very important criterion of malignancy on future developing the computer-aided diagnosis for ultrasound. In the future, this technique can be adopted in a computer-aided diagnosis system combined with other diagnosis features for improving the diagnosis performance.

Identification of NV-F virus DNA in hepatocellular carcinoma

A fragment of DNA sequence derived from a hepatotropic virus, named NV-F was isolated recently. The aim of this study was to examine whether this virus was associated with hepatocellular carcinoma (HCC). Total cellular DNA was extracted from hepatocellular carcinoma tissues. NV-F virus DNA was detected by PCR. The PCR products were subjected to sequence analysis. Of the 78 HCC samples included, 12 (15.4%) were positive for NV-F virus DNA. Sequence analysis of the 12 amplified DNA fragments revealed a point mutation in one of them. The clinicopathological parameters between patients with and without NV-F virus infection were compared. It was found that patients with NV-F virus infection were older than those without NV-F virus infection (mean ages, 61.5 versus 52.5 years; P = 0.032). Otherwise, no difference was observed between the two groups. Of the 12 HCC patients positive for NV-F virus DNA, 11 patients were co-infected by either hepatitis B or C virus. The remaining patient was a Taiwanese aboriginal inhabitant with cryptogenic cirrhosis. In conclusion, NV-F virus DNA was identified in 15.4% of HCC tissues. HCC patients with NV-F virus infection were significantly older than those without NV-F virus infection.