Actopaxin: a novel regulator of cell migration and invasion in human hepatocellular carcinoma

Oral presentationpublished_or_final_versionThe 15th Annual Research Conference of the Department of Medicine, The University of Hong Kong, Hong Kong, 16 January 2010. In Hong Kong Medical Journal, 2010, v. 16, suppl. 1, p. 49, abstract no. 8

Frontal mucocele masked as upper lid abcess-a case report

Frontal mucocele is not commonly masked as upper lid abscess.A 72-year-old Chinese man with underlying hyperthyroidism complained of left upper eyelid swelling of 6 months duration. The swelling had persisted and worsen when intravenous antibiotic was changed oral type. Visual acuity on presentation was hand motion and reverse relative afferent pupillary defect was present. Because the swelling was large and resulted in mechanical ptosis and ophthalmoplegia, a CT imaging was performed, which showed huge left frontal mucocele eroding the supereromedial orbital rim. The left globe was displaced inferolaterally but there was no extension into brain parenchyma. Fundus examination showed pale optic disc with dull macula. Old laser marks were seen at peripheral fundus. Referral to ortholaryngologist was made and endoscopic sinus surgery and evacuation of mucopyocoele was done. Culture and sensitivity of the fluid showed no organism. He recovered well postoperatively with additional two weeks of antibiotics. We highlight the necessity of surgical drainage of mucocele, following a course of antibiotic

Recommending anchor points in structure-preserving hypertext document retrieval

Traditional WWW search engines index and recommend individual Web pages to assist users in locating relevant documents. Users are often overwhelmed by the large answer set recommended by the search engines. The logical starting point of the hyper-document is thus hidden among the large basket of matching pages. Users need to spend a lot of effort browsing through the pages to locate the starting point, a very time consuming process. This paper studies the anchor point indexing problem. The anchor points of a given user query is a small set of key pages from which the larger set of documents that are relevant to the query can be easily reached. The use of anchor points help solve the problems of huge answer set and low precision suffered by most search engines by considering the hyper-link structures of the relevant documents, and by providing a summary view of the result set.published_or_final_versio

Hepatic resection for colorectal liver metastases: prospective study.

OBJECTIVE: To assess the operative and long-term survival outcomes of hepatic resection for colorectal liver metastases during an 11-year period in a tertiary referral centre in Hong Kong. DESIGN: Prospective study. SETTING: University teaching hospital, Hong Kong. SUBJECTS AND METHODS: Between January 1989 and December 1999, 72 patients underwent hepatic resection for colorectal liver metastases. Clinical, pathological, and outcome data were prospectively collected and analysed. Factors affecting long-term survival were also evaluated. RESULTS: Twenty-five (34.7%) patients were found to have synchronous hepatic metastasis at the time of colorectal resection. Fifty-two (72.2%) patients underwent major hepatic resection. The operative morbidity and hospital mortality rates were 19% and 4%, respectively. The 5-year survival rate after hepatectomy was 31.9%. The median disease-free survival and median overall cumulative survival were 18.5 months and 30.8 months, respectively. On multivariate analysis, a high preoperative serum carcinoembryonic antigen level (>200 ng/mL) and tumour involvement of the resection margin at histology were the two independent risk factors that adversely affected survival outcome. CONCLUSION: Hepatic resection for colorectal liver metastases can be performed safely, with minimal operative mortality and acceptable morbidity, and results in satisfactory survival. High preoperative serum carcinoembryonic antigen level and histological involvement of resection margin by cancer adversely affect the survival outcome.published_or_final_versio

PAK4 phosphorylates p53 at serine 215 to promote liver cancer metastasis

PAK4 kinase contributes to signaling pathways controlling cancer cell transformation, invasion and survival, but its clinicopathological impact has begun to emerge only recently. Here we report that PAK4 overexpression in hepatocellular carcinoma (HCC) conveys aggressive metastatic properties. A novel nuclear splice isoform of PAK4 lacking exon 2 sequences was isolated as part of our studies. By stably overexpressing or silencing PAK4 in HCC cells we showed that it was critical for their migration. Mechanistic investigations in this setting revealed that PAK4 directly phosphorylated p53 at S215, which not only attenuated transcriptional transactivation activity but also inhibited p53-mediated suppression of HCC cell invasion. Taken together, our results showed how PAK4 overexpression in HCC promotes metastatic invasion by regulating p53 phosphorylation.postprin

CDK5RAP3 is a novel repressor of p14ARF in hepatocellular carcinoma cells

CDK5 regulatory subunit associated protein 3 (CDK5RAP3) is a novel activator of PAK4 and processes important pro-metastatic function in hepatocarcinogenesis. However, it remains unclear if there are other mechanisms by which CDK5RAP3 promotes HCC metastasis. Here, we showed that in CDK5RAP3 stable knockdown SMMC-7721 HCC cells, p14(ARF) tumor suppressor was upregulated at protein and mRNA levels, and ectopic expression of CDK5RAP3 was found to repress the transcription of p14(ARF). Using chromatin immunoprecipitation assay, we demonstrated that CDK5RAP3 bound to p14(ARF) promoter in vivo. Furthermore, knockdown of p14(ARF) in CDK5RAP3 stable knockdown HCC cells reversed the suppression of HCC cell invasiveness mediated by knockdown of CDK5RAP3. Taken together, our findings provide the new evidence that overexpression of CDK5RAP3 promotes HCC metastasis via downregulation of p14(ARF).published_or_final_versio

A preclinical study on the combination therapy of everolimus and transarterial chemoembolization in hepatocellular carcinoma

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Over-expression of miR-106b promotes cell migration and metastasis in hepatocellular carcinoma by activating epithelial-mesenchymal transition process

Hepatocellular carcinoma (HCC) is one the the most fatal cancers worldwide. The poor prognosis of HCC is mainly due to the developement of distance metastasis. To investigate the mechanism of metastasis in HCC, an orthotopic HCC metastasis animal model was established. Two sets of primary liver tumor cell lines and corresponding lung metastasis cell lines were generated. In vitro functional analysis demonstrated that the metastatic cell line had higher invasion and migration ability when compared with the primary liver tumor cell line. These cell lines were subjected to microRNA (miRNAs) microarray analysis to identify differentially expressed miRNAs which were associated with the developement of metastasis in vivo. Fifteen human miRNAs, including miR-106b, were differentially expressed in 2 metastatic cell lines compared with the primary tumor cell lines. The clinical significance of miR-106b in 99 HCC clinical samples was studied. The results demonstrated that miR-106b was over-expressed in HCC tumor tissue compared with adjacent non-tumor tissue (p = 0.0005), and overexpression of miR-106b was signficantly correlated with higher tumor grade (p = 0.018). Further functional studies demonstrated that miR-106b could promote cell migration and stress fiber formation by over-expressing RhoGTPases, RhoA and RhoC. In vivo functional studies also showed that over-expression of miR-106b promoted HCC metastasis. These effects were related to the activation of the epithelial-mesenchymal transition (EMT) process. Our results suggested that miR-106b expression contributed to HCC metastasis by activating the EMT process promoting cell migration in vitro and metastasis in vivo. © 2013 Yau et al.published_or_final_versio

Preventive Treatment with Ketamine attenuates the ischaemia-reperfusion response in a chronic postichaemia pain model

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Efficient attenuation of Friedreich's ataxia (FRDA) cardiomyopathy by modulation of iron homeostasis-human induced pluripotent stem cell (hiPSC) as a drug screening platform for FRDA

Friedreich’s ataxia (FRDA), a recessive neurodegenerative disorder commonly associated with hypertrophic cardiomyopathy, is caused by silencing of the frataxin (FXN) gene encoding the mitochondrial protein involved in iron-sulfur cluster biosynthesis. We aimed to utilize our previously established FRDA human induced pluripotent stem cell (hiPSC) derived cardiomyocytes model as a platform to assess the efficacy of treatment with either the antioxidant coenzyme Q10 analog, idebenone (IDE) or the iron chelator, deferiprone (DFP), which are both under clinical trial. In fact, DFP was able to more significantly suppress synthesis of reactive oxygen species (ROS) than IDE at the dosages of 10 nM and 25 μM respectively which agreed with the reduced rate of intracellular accumulation of iron by DFP treatment from 25 to 50 µM. With regard to cardiac electrical-contraction (EC) coupling function, decay velocity of calcium handling kinetics in FRDA-hiPSC-cardiomyocytes was significantly improved by DFP treatment but not by IDE. Further mechanistic studies revealed DFP also modulated iron induced mitochondrial stress as reflected by mitochondria network disorganization and decline in level of respiratory chain protein. In addition, iron-response protein (IRP-1) regulatory loop was overridden by DFP as reflected by the attenuated transferrin receptor (TSFR) suppression thereby reducing further iron uptake.published_or_final_versio