Differentiation between dysplastic nodule and early-stage hepatocellular carcinoma: The utility of conventional MR imaging

AIM: To elucidate the variety of ways early-stage hepatocellular carcinoma (HCC) can appear on magnetic resonance (MR) imaging by analyzing T1-weighted, T2-weighted, and gadolinium-enhanced dynamic studies.

METHODS: Seventy-three patients with well-differentiated HCC (wHCC) or dysplastic nodules were retrospectively identified from medical records, and new histological sections were prepared and reviewed. The tumor nodules were categorized into three groups: dysplastic nodule (DN), wHCC compatible with Edmondson-Steiner grade I HCC (w1-HCC), and wHCC compatible with Edmondson-Steiner grade II HCC (w2-HCC). The signal intensity on pre-contrast MR imaging and the enhancing pattern for each tumor were recorded and compared between the three tumor groups.

RESULTS: Among the 73 patients, 14 were diagnosed as having DN, 40 were diagnosed as having w1-HCC, and 19 were diagnosed as having w2-HCC. Hyperintensity measurements on T2-weighted axial images (T2WI) were statistically significant between DNs and wHCC (P = 0.006) and between DN and w1-HCC (P = 0.02). The other imaging features revealed no significant differences between DN and wHCC or between DN and w1-HCC. Hyperintensity on both T1W out-phase imaging (P = 0.007) and arterial enhancement on dynamic study (P = 0.005) showed statistically significant differences between w1-HCC and w2-HCC. The other imaging features revealed no significant differences between w1-HCC and w2-HCC.

CONCLUSION: In the follow-up for a cirrhotic nodule, increased signal intensity on T2WI may be a sign of malignant transformation. Furthermore, a noted loss of hyperintensity on T1WI and the detection of arterial enhancement might indicate further progression of the histological grade.

Comparison of IHC, FISH and RT-PCR methods for detection of ALK rearrangements in 312 non-small cell lung cancer patients in Taiwan

Background

Recently Echinoderm microtubule-associated protein-like 4- anaplastic lymphoma kinase (EML4-ALK) fusion gene has become an important biomarker for ALK tyrosine kinase inhibitor (crizotinib) treatment in NSCLC. However, the best detection method and the significance of EML4-ALK variant types remain uncertain.

Methods

Reverse transcriptase-polymerase chain reaction (RT-PCR), fluorescence in Situ hybridization (FISH) and Immunohistochemical (IHC) stain were performed on tumor tissues of 312 NSCLC patients for detection of ALK rearrangements. Mutation analyses for EGFR and KRAS genes were also performed.

Results

Thirteen of the 312 patients (4.17%) had ALK rearrangements detected by RT-PCR. If RT-PCR data was used as the gold standard, FISH tests had a low sensitivity (58.33%), but very good specificity (99.32%). IHC stain had better sensitivity (91.67%) than FISH, but lower specificity (79.52%), when the cut off was IHC2+. All of the 8 patients with high abundance of EML4-ALK positive cells in tumor tissues (assessed by the signal intensities of the RT-PCR product), were also have high expression of ALK protein (IHC3+), and positive for FISH, except one failed in FISH. Variants 3a+3b (4/5, 80%) of EML4-ALK fusion gene were more common to have high abundance of EML4-ALK positive cells in tumor tissues than variant 1 (1/3, 33.3%). Meta-analysis of the published data of 2273 NSCLC patients revealed that variant 3 (23/44, 52.3%) was the most common type in Chinese population, while variant 1 (28/37, 75.7%) was most common in Caucasian.

Conclusions

Among the three detection methods, RT-PCR could detect not only the presence of EML4-ALK fusion gene and their variant types, but also the abundance of EML4-ALK positive cells in NSCLC tumor tissues. The latter two factors might affect the treatment response to anti-ALK inhibitor. Including RT-PCR as a diagnostic test for ALK inhibitor treatment in the prospective clinical trials is recommended.

Expression of GOLM1 correlates with prognosis in human hepatocellular carcinoma

BACKGROUND

Serum Golgi membrane protein 1 (GOLM1) is a novel biomarker for hepatocellular carcinoma (HCC). However, few studies have investigated the relationship between GOLM1 protein expression and clinicopathologic features in HCC patients. The aim of this study was to investigate the expression of GOLM1 in human HCC and its correlation with clinicopathologic parameters.

METHODS

Clinicopathologic data were obtained through a detailed retrospective review of the medical records of 193 patients with HCC who had undergone surgical resection between 1990 and 2006 at the Taipei Veterans General Hospital. Another 120 HCC tissue samples provided by the Taiwan Liver Cancer Network were used as validation cohort. Immunohistochemical staining was used to determine the expression of GOLM1 in archived formalin-fixed, paraffin-embedded tissue specimens.

RESULTS

GOLM1 expression was significantly higher in resected HCC tumor tissues than in corresponding normal liver tissues (p < 0.01). After a median follow-up of 51 months, multivariate analysis showed that portal vein invasion (hazard ratio [HR], 1.515; 95 % confidence interval [95 % CI], 1.008-2.277; p = 0.046) and high GOLM1 protein expression (HR, 1.696; 95 % CI, 1.160-2.479; p = 0.006) were independent prognostic factors for poor overall survival. High GOLM1 protein expression still significantly correlates with worse overall survival as well as disease-free survival in the validation cohort (p < 0.001 and p = 0.002).

CONCLUSIONS

Overexpression of GOLM1 is associated with poor prognosis in human HCC.

Development of a non-invasive fibrosis test for chronic hepatitis B patients and comparison with other unpatented scores

BACKGROUND

Despite the availability of patented non-invasive methods, evaluation of the degrees of liver fibrosis remains difficult when conducting a retrospective study. Such inadequacy is largely caused by requirement of biochemical parameters rarely performed in routine clinical tests. We developed a novel fibrosis HB-F score using commonly performed tests for HBV infected patients.

METHODS

424 patients with chronic HBV infection were included. Using clinical and virological data, HB-F score was developed from a training cohort (n = 213) and validated in a separate cohort (n = 211). The performance was compared with five other unpatented scores using ROC curves.

RESULTS

Univariate and multivariate analysis revealed that age, AST/ALT ratio, platelet count and prothrombin time prolongation were significantly associated with the ISHAK fibrosis score, and were used to calculate the HB-F score. When HB-F was used to assess prominent fibrosis and cirrhosis, the AUC was 0.81 and 0.80 respectively in the training cohort, and 0.80 and 0.76 respectively in the validation cohort. HB-F had the highest AUC compared with other scores. Furthermore, in assessing paired liver biopsies with increase or decrease of ISHAK scores, HB-F showed significant change in the same direction.

CONCLUSIONS

A new non-invasive score was developed, which could be used to assess severity of liver fibrosis in retrospective longitudinal studies in HBV patients.

Correlation of anaplastic lymphoma kinase overexpression and the EML4-ALK fusion gene in non-small cell lung cancer by immunohistochemical study

BACKGROUND

Recently the echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) fusion gene with transforming activity was identified in non-small cell lung cancer (NSCLC). In addition, NSCLC patients with the EML4-ALK fusion gene had a dramatic response and longer progression free survival after ALK inhibitor treatment than those without this fusion gene. However, the incidence and clinical and molecular characteristics of the EML4-ALK fusion gene in NSCLC patients of Taiwan are still unclear.

METHODS

Sixty-four fresh frozen tumor specimens were obtained from the tissue bank of Chang Gung Memorial Hospital for RNA extraction and EML4-ALK fusion gene detection. Paraffin sections of lung tumors from all of these patients were available and were analyzed for ALK protein expression by immunohistochemical (IHC) study. The results were correlated with clinical and molecular biomarkers.

RESULTS

Three of the 64 tumors (4.7%) had the EML4-ALK fusion gene. Two were adenocarcinomas, and one was adenosquamous carcinoma. Twenty patients with non-squamous cell carcinomas had epidermal growth factor receptor (EGFR) mutations, so the EML4-ALK fusion gene was found in 14.3% of EGFR wild type non-squamous cell carcinomas. Two tumors were variant 3 (3a+3b with 3b predominant) and had strong staining (3+) for ALK by IHC stains. One tumor was variant 1 and had moderate staining (2+) for ALK. None of the ALK wild type tumors had strong staining for ALK. When compared with other clinical and molecular features, only the IHC stain for ALK was significantly correlated with the EML4-ALK fusion gene (p = 0.0002).

CONCLUSIONS

ALK overexpression detected by IHC study could be a promising detection method for the EML4-ALK fusion gene and is worth further confirmation with more samples.

KRAS mutation status-stratified randomized phase II trial of GEMOX with and without cetuximab in advanced biliary tract cancer (ABTC): The TCOG T1210 trial

4018

Background: Gemcitabine/platinum combination is considered as globally acceptable standard care in patients with ABTC. Two recently published randomized trials showed adding EGFR antagonist, either erlotinib or cetuximab, does not further improve the clinical outcomes of gemcitabine/oxaliplatin (GEMOX)-treated ABTC patients. However, the impact of KRAS mutation status on the results of both studies was not properly addressed. Methods: A prospective, multicenter randomized, phase II trial to evaluate the therapeutic efficacies of adding cetuximab to GEMOX in patients with ABTC, in which eligible patients were stratified by status of KRAS mutation and ECOG PS, and tumor location then randomized to receive either GEMOX (gemcitabine 800 mg/m2, fixed-rate infusion and oxaliplatin 85 mg/m2, i.v., Q 2 weeks) or GEMOX plus cetuximab (500 mg/m2, i.v., Q 2 weeks, C-GEMOX). The primary endpoint was overall response rate (ORR). As an exploratory trial, 120 (60 per arm) patients was estimated to detect a two-tailed 10% difference in ORR (20% in GEMOX and 30% in C-GEMOX) with a significant level of a=0.2 and b=0.5. Results: Between Nov 2010 and May 2012, a total of 122 patients were accrued. The demography was male: 47.5%, median age: 60 y/o, ECOG PS 0/1: 28.7%/71.3%, IHCC/EHCC/GBC: 71.3%/16.4%/12.3%, KRAS mutation: 36.1%, with locally advanced/metastatic diseases: 32.0%/68.0%, and prior surgical resection: 41.8%. On intent-to-treat analysis, the ORR and DCR in the C-GEMOX (N=62) and GEMOX (N-60) arms was 27.3% vs 15.0% (p=0.1223) and 82.2% vs 60.0% (p=0.0090), respectively (Fisher’s exact test); while the median PFS was 7.1 vs 4.0 months (p= 0.0069) and median OS was 10.3 vs 8.8 months (p=0.4057), respectively (log-rank test). Planned subgroup analysis showed the 43 patients with KRAS mutated tumors benefited more from cetuximab therapy, with a DCR of 78.3% vs 38.1% (p=0.0132), median PFS of 7.0 vs 1.9 months (p=0.0351) and median OS of 10.3 vs 6.6 months (p=0.6924). Conclusions: Adding cetuximab significant improves the DCR and PFS of GEMOX in ABTC patients, notably in subpopulation with KRAS mutated tumors. Larger-scale phase III trial is warranted. Clinical trial information: NCT01267344.

Focal Nodular Hyperplasia and Hepatocellular Adenoma around the World Viewed through the Scope of the Immunopathological Classification

Focal nodular hyperplasia (FNH) and hepatocellular adenoma (HCA) are benign hepatocellular tumors. The risk of bleeding and malignant transformation of HCA are strong arguments to differentiate HCA from FNH. Despite great progress that has been made in the differential radiological diagnosis of the 2 types of nodules, liver biopsy is sometimes necessary to separate the 2 entities. Identification of HCA subtypes using immunohistochemical techniques, namely, HNF1A-inactivated HCA (35-40%), inflammatory HCA (IHCA), and beta-catenin-mutated inflammatory HCA (b-IHCA) (50-55%), beta-catenin-activated HCA (5-10%), and unclassified HCA (10%) has greatly improved the diagnostic accuracy of benign hepatocellular nodules. If HCA malignant transformation occurs in all HCA subgroups, the risk is by far the highest in the β -catenin-mutated subgroups (b-HCA, b-IHCA). In the coming decade the management of HCA will be more dependent on the identification of HCA subtypes, particularly for smaller nodules (<5 cm) in terms of imaging, follow-up, and resection.

Gorham syndrome with postoperative respiratory failure and requiring prolonged mechanical ventilation

Gorham syndrome is a rare disease that presents as progressive osteolysis, and may affect any part of the skeleton. The pathologic process involves the replacement of normal bone by aggressively expanding but non-neoplastic vascular tissue, resulting in massive osteolysis of the adjacent bone. If the spine and ribs are affected, the subsequent kyphosis and chest wall deformity may cause severe restrictive ventilatory impairment. We report a 34-year-old male with Gorham syndrome presenting as progressive kyphosis, severe back pain, unstable gait, and exertional dyspnea. Pulmonary function testing revealed severe restrictive ventilatory impairment. He underwent spinal surgery but could not be extubated after surgery. Postoperative left lower lung pneumonia and respiratory failure required prolonged mechanical ventilation. After a weaning program of pressure support ventilation and T-piece spontaneous breathing trials, he was successfully weaned from mechanical ventilation.

Temperature and boundary influence on cement hydration monitoring using embedded piezoelectric transducers

In this study, the hydration process was monitored using embedded ultrasonic transducers. It was found that the ultrasonic amplitude decreased and fluctuated at the very early age, several hours after the beginning of fast hydration. The embedded transducers are very different from the surface coupled ones for they were directly influenced by the cement paste, such as the varying temperature and the boundary condition. Experiments were carried out to find out which factor result in such decrease and fluctuation. Test results showed that both the temperature and boundary conditions affect the ultrasonic measurement. When the hydration progressed under constant temperature, the amplitude of the ultrasonic wave decreased smoothly during certain period. When the hardened specimen was tested, it was found that the amplitude would decrease obviously with the increasing of temperature and vice versa. The findings could be used to interpret the amplitude plot obtained in the normal hydration monitoring using embedded transducers.

Glycine N-methyltransferase deficiency affects Niemann-Pick type C2 protein stability and regulates hepatic cholesterol homeostasis

Nonalcoholic fatty liver disease (NAFLD) is associated with the development of metabolic syndromes and hepatocellular carcinoma (HCC). Cholesterol accumulation is related to NAFLD, whereas its detailed mechanism is not fully understood. Previously, we reported that glycine N-methyltransferase (GNMT) knockout (Gnmt(-/-)) mice develop chronic hepatitis and HCC. In this study, we showed that Gnmt(-/-) mice had hyperlipidemia and steatohepatitis. Single photon emission computed tomography images of mice injected with (131)I-labeled 6β-iodocholesterol demonstrated that Gnmt(-/-) mice had slower hepatic cholesterol uptake and excretion rates than wild-type mice. In addition, genes related to cholesterol uptake (scavenger receptor class B type 1 [SR-B1] and ATP-binding cassette A1 [ABCA1]), intracellular trafficking (Niemann-Pick type C1 protein [NPC1] and Niemann-Pick type C2 protein [NPC2]) and excretion (ATP-binding cassette G1 [ABCG1]) were downregulated in Gnmt(-/-) mice. Yeast two-hybrid screenings and coimmunoprecipitation assays elucidated that the C conserved region (81-105 amino acids) of NPC2 interacts with the carboxyl-terminal fragment (171-295 amino acids) of GNMT. Confocal microscopy demonstrated that when cells were treated with low-density lipoprotein, NPC2 was released from lysosomes and interacts with GNMT in the cytosol. Overexpression of GNMT doubled the half-lives of both NPC2 isoforms and reduced cholesterol accumulation in cells. Furthermore, GNMT was downregulated in the liver tissues from patients suffering with NAFLD as well as from mice fed a high-fat diet, high-cholesterol diet or methionine/choline-deficient diet. In conclusion, our study demonstrated that GNMT regulates the homeostasis of cholesterol metabolism, and hepatic cholesterol accumulation may result from downregulation of GNMT and instability of its interactive protein NPC2. Novel therapeutics for steatohepatitis and HCC may be developed by using this concept.

Major Functional Transcriptome of an Inferred Center Regulator of an ER(-) Breast Cancer Model System

We aimed to find clinically relevant gene activities ruled by the signal transducer and activator of transcription 3 (STAT3) proteins in an ER(-) breast cancer population via network approach. STAT3 is negatively associated with both lymph nodal category and stage. MYC is a component of STAT3 network. MYC and STAT3 may co-regulate gene expressions for Warburg effect, stem cell like phenotype, cell proliferation and angiogenesis. We identified a STAT3 network in silico showing its ability in predicting its target gene expressions primarily for specific tumor subtype, tumor progression, treatment options and prognostic features. The aberrant expressions of MYC and STAT3 are enriched in triple negatives (TN). They promote histological grade, vascularity, metastasis and tumor anti-apoptotic activities. VEGFA, STAT3, FOXM1 and METAP2 are druggable targets. High levels of METAP2, MMP7, IGF2 and IGF2R are unfavorable prognostic factors. STAT3 is an inferred center regulator at early cancer development predominantly in TN.

Functional characterization of glycine N-methyltransferase and its interactive protein DEPDC6/DEPTOR in hepatocellular carcinoma

Glycine N-methyltransferase (GNMT) is a tumor suppressor for hepatocellular carcinoma (HCC). High rates of Gnmt knockout mice developed HCC. Epigenetic alteration and dysregulation of several pathways including wingless-type MMTV integration site (Wnt), mitogen-activated protein kinase (MAPK) and Janus kinase and signal transducer and activator of transcription (JAK-STAT) are associated with HCC development in Gnmt knockout mice. We hypothesized that GNMT may regulate signal transduction through interacting with other proteins directly. In this report, we identified a mammalian target of rapamycin (mTOR) inhibitor (DEP domain containing MTOR-interacting protein [DEPDC6/DEPTOR]) as a GNMT-binding protein by using yeast two-hybrid screening. Fluorescence resonance energy transfer assay demonstrated that the C-terminal half of GNMT interact with the PSD-95/Dlg1/ZO-1 (PDZ) domain of DEPDC6/DEPTOR. Immunohistochemical staining showed that 27.5% (14/51) of HCC patients had higher expression levels of DEPDC6/DEPTOR in the tumorous tissues than in tumor-adjacent tissues, especially among HCC patients with hepatitis B viral infection (odds ratio 10.3, 95% confidence interval [CI] 1.05-11.3) or patients with poor prognosis (death hazard ratio 4.51, 95% CI 1.60-12.7). In terms of molecular mechanism, knockdown of DEPDC6/DEPTOR expression in HuH-7 cells caused S6K and 4E-BP activation, but suppressed Akt. Overexpression of DEPDC6/DEPTOR activated Akt and increased survival of HCC cells. Overexpression of GNMT caused activation of mTOR/raptor downstream signaling and delayed G2/M cell cycle progression, which altogether resulted in cellular senescence. Furthermore, GNMT reduced proliferation of HuH-7 cells and sensitized them to rapamycin treatment both in vitro and in vivo. In conclusion, GNMT regulates HCC growth in part through interacting with DEPDC6/DEPTOR and modulating mTOR/raptor signaling pathway. Both GNMT and DEPDC6/DEPTOR are potential targets for developing therapeutics for HCC.

Erlotinib treatment in patients with advanced lung adenocarcinoma with CISH-positive and CISH-negative EGFR gene alterations

BACKGROUND

Epidermal growth factor receptor (EGFR) positivity as assessed by chromogenic in situ hybridization (CISH) has been demonstrated to be associated with EGFR mutation status. This study was conducted to compare the responsiveness of CISH-positive and CISH-negative lung adenocarcinomas to erlotinib.

PATIENTS AND METHODS

Patients received erlotinib (150 mg/day) alone until disease progression or intolerable toxicity. EGFR gene status was examined by CISH. The response rate (RR), progression-free survival (PFS), overall survival (OS) and toxicity profiles were assessed.

RESULTS

Thirty-one patients underwent response evaluations and CISH analyses, 12 of whom harboured CISH-positive adenocarcinomas. The overall RR (p=0.035), median PFS (p=0.091) and median OS (p=0.408) were higher in the CISH-positive group. No difference in toxicity profiles was observed between these two groups.

CONCLUSION

EGFR status as assessed by CISH can predict the response to erlotinib in patients with advanced lung adenocarcinoma.

A Cullin3-KLHL20 Ubiquitin ligase-dependent pathway targets PML to potentiate HIF-1 signaling and prostate cancer progression

Tumor hypoxia is associated with disease progression and treatment failure, but the hypoxia signaling mechanism is not fully understood. Here, we show that KLHL20, a Cullin3 (Cul3) substrate adaptor induced by HIF-1, coordinates with the actions of CDK1/2 and Pin1 to mediate hypoxia-induced PML proteasomal degradation. Furthermore, this PML destruction pathway participates in a feedback mechanism to maximize HIF-1α induction, thereby potentiating multiple tumor hypoxia responses, including metabolic reprogramming, epithelial-mesenchymal transition, migration, tumor growth, angiogenesis, and chemoresistance. In human prostate cancer, overexpression of HIF-1α, KLHL20, and Pin1 correlates with PML down-regulation, and hyperactivation of the PML destruction pathway is associated with disease progression. Our study indicates that the KLHL20-mediated PML degradation and HIF-1α autoregulation play key roles in tumor progression.

Epidermal growth factor receptor mutations in patients with oral cavity cancer in a betel nut chewing-prevalent area

BACKGROUND

Epidermal growth factor receptor (EGFR) mutations exist in patients with oral cavity squamous cell carcinoma (OSCC), but few data about mutation patterns with clinical outcomes were reported.

METHODS

Fifty-six formalin-fixed paraffin-embedded tumor samples were obtained surgically from OSCC patients. Direct sequencing of EGFR was carried out using nested polymerase chain reaction. The relationship between EGFR status and clinical courses was analyzed.

RESULTS

Two (3.56%) missense mutations (G857R; L862Q) in exon 20 were identified. Two types of silent mutation, A859A in exon 21 (1.79%) and Q787Q mutations in exon 20 (30.36%), were also found. No mutation was detected in exons 18 and 19. No significant difference in disease-free survival and locoregional control rate was shown between patients with and without Q787Q mutation.

CONCLUSIONS

We identified a high frequency of Q787Q mutation and a less prevalent active EGFR mutation in OSCC patients in Taiwan where betel nut is commonly chewed.

Vaccinia H1-related phosphatase is a phosphatase of ErbB receptors and is down-regulated in non-small cell lung cancer

Vaccinia H1-related phosphatase (VHR) is classified as a dual specificity phosphatase. Unlike typical dual specificity phosphatases, VHR lacks the MAPK-binding domain and shows poor activity against MAPKs. We found that EGF receptor (EGFR) was a direct substrate of VHR and that overexpression of VHR down-regulated EGFR phosphorylation, particularly at Tyr-992 residue. Expression of VHR inhibited the activation of phospholipase Cγ and protein kinase C, both downstream effectors of Tyr-992 phosphorylation of EGFR. Decreasing VHR expression by RNA interference caused higher EGFR phosphorylation at Tyr-992. In addition to EGFR, VHR also directly dephosphorylated ErbB2. Consistent with these results, suppression of VHR augmented the foci formation ability of H1299 non-small cell lung cancer (NSCLC) cells, whereas overexpression of VHR suppressed cell growth in both two- and three-dimensional cultures. Expression of VHR also suppressed tumor formation in a mouse xenograft model. Furthermore, VHR expression was significantly lower in NSCLC tissues in comparison to that in normal lung tissues. Collectively, this study shows that down-regulation of VHR expression enhances the signaling of ErbB receptors and may be involved in NSCLC pathogenesis.

Higher susceptibility to aflatoxin B(1)-related hepatocellular carcinoma in glycine N-methyltransferase knockout mice

In both humans and rodents, males are known to be more susceptible than females to hepatocarcinogenesis. We have previously reported that glycine N-methyltransferase (GNMT) interacts with aflatoxin B(1) (AFB(1)) and reduces both AFB(1)-DNA adduct formation and hepatocellular carcinoma (HCC) in mice. We also reported that 50% of the males and 100% of the females in a small group of Gnmt null (Gnmt-/-) mice developed HCC, with first dysplastic hepatocellular nodules detected at mean ages of 17 and 16.5 months, respectively. In our study, we tested our hypothesis that male and female Gnmt-/- mice are susceptible to AFB(1) carcinogenesis, and that the absence of Gnmt expression may accelerate AFB(1)-induced liver tumorigenesis. We inoculated Gnmt-/- and wild-type mice intraperitoneally with AFB(1) at 7 days and 9 weeks of age and periodically examined them using ultrasound. Dysplastic hepatocellular nodules were detected in six of eight males and five of five females at 12.7 and 12 months of ages, respectively. Dysplastic hepatocellular nodules from 5/8 (62.5%) male and 4/5 (80%) female Gnmt-/- mice were diagnosed as having HCC, ∼6 months earlier than AFB(1)-treated wild-type mice. Results from microarray and real-time PCR analyses indicate that five detoxification pathway-related genes were downregulated in AFB(1)-treated Gnmt-/- mice: Cyp1a2, Cyp3a44, Cyp2d22, Gsta4 and Abca8a. In summary, we observed overall higher susceptibility to AFB(1)-related HCC in Gnmt-/- mice, further evidence that GNMT overexpression is an important contributing factor to liver cancer resistance.

Downregulation of Signaling-active IGF-1 by Dipeptidyl Peptidase IV (DPP-IV)

Functioning as an extracellular protease, dipeptidyl peptidase IV (DPP-IV) preferentially cleaves the peptide bond after the penultimate proline residue. We report here that DPP-IV cleaves the first two amino acids from insulin-like growth factor 1 (IGF-1), revealed by mass spectrometry. The kinetic parameters of the proteolytic cleavage indicate that this reaction is physiologically relevant. Interestingly, truncated IGF-1 is less potent than the full-length protein in activating the IGF-1R, but binds more readily to IGF-binding protein 3 (IGFBP3). Quantitative RT-PCR showed that the level of DPP-IV mRNA is dramatically lower in lung squamous cell carcinoma tissues than in adjacent nonneoplastic lung tissues. However, this reduction was not observed in lung adenocarcinoma tissues. Our study suggests a possible link between IGF-1 and DPP-IV in cancer development in a specific tumor niche. A DPP-IV-related pathway may be important in mitigating IGF-1 signaling. Consequently, a robust IGF signaling pathway may accelerate early carcinogenesis in environments lacking DPP-IV.

Notch1 expression predicts an unfavorable prognosis and serves as a therapeutic target of patients with neuroblastoma

PURPOSE

Notch signaling has been implicated to play a critical role in the tumorigenesis of neuroblastoma (NB) and can modulate calreticulin (CRT) expression that strongly correlates with tumor differentiation and favorable prognosis of NB. We thus sought to determine how Notch regulates CRT expression and affects NB tumor behavior.

EXPERIMENTAL DESIGN

The Notch-dependent regulation of CRT expression in cultured NB cells was analyzed by confocal microscopy and Western blotting. Notch1 protein expression in 85 NB tumors was examined by immunohistochemistry and correlated with the clinicopathologic/biological characters of NB patients. The progression of NB tumors in response to attenuated Notch signaling was examined by using a xenograft mouse model.

RESULTS

We showed that CRT is essential for the neuronal differentiation of NB cells elicited by inhibition of Notch signaling. This effect was mediated by a c-Jun-NH(2)-kinase-dependent pathway. Furthermore, NB tumors with elevated Notch1 protein expression were strongly correlated with advanced tumor stages, MYCN amplification, an undifferentiated histology, as well as a low CRT expression level. Most importantly, the opposing effect between Notch1 and CRT could reciprocally affect the survival of NB patients. The administration of a gamma-secretase inhibitor into a xenograft mouse model of NB significantly suppressed the tumor progression.

CONCLUSIONS

Our findings provide the first evidence that a c-Jun-NH(2)-kinase-CRT-dependent pathway is essential for the neuronal differentiation elicited by Notch signaling blockade and that Notch1 and CRT can synergistically predict the clinical outcomes of NB patients. The present data suggest that Notch signaling could be a therapeutic target for NB.

Solitary primary tracheal small-cell lung cancer causing acute respiratory failure: diagnosis and treatment

Small-cell lung cancer often presents as an extensive cancer, and rarely as a solitary tracheal tumor. We report a 41-year-old male smoker with dyspnea and wheezing that was initially diagnosed as asthma and treated with bronchodilators. He was later intubated for acute respiratory failure, and computed tomography revealed a tracheal mass. Solitary primary small-cell lung cancer was diagnosed via bronchoscopic biopsy. The patient received bronchoscopic electro-surgery and was successfully extubated. Concurrent chemo-radiotherapy was performed due to the stage IV small-cell lung cancer.

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.