Identification and characterization of tropomyosin 3 associated with granulin-epithelin precursor in human hepatocellular carcinoma

Background and Aim: Granulin-epithelin precursor (GEP) has previously been reported to control cancer growth, invasion, chemo-resistance, and served as novel therapeutic target for cancer treatment. However, the nature and characteristics of GEP interacting partner remain unclear. The present study aims to identify and characterize the novel predominant interacting partner of GEP using co-immunoprecipitation and mass spectrometry. Methods and Results: Specific anti-GEP monoclonal antibody was used to capture GEP and its interacting partner from the protein extract of the liver cancer cells Hep3B. The precipitated proteins were analyzed by SDS-PAGE, followed by mass spectrometry and the protein identity was demonstrated to be tropomyosin 3 (TPM3). The interaction has been validated in additional cell models using anti-TPM3 antibody and immunoblot to confirm GEP as the interacting partner. GEP and TPM3 expressions were then examined by real-time quantitative RT-PCR in clinical samples, and their transcript levels were significantly correlated. Elevated TPM3 levels were observed in liver cancer compared with the adjacent non-tumorous liver, and patients with elevated TPM3 levels were shown to have poor recurrence-free survival. Protein expression of GEP and TPM3 was observed only in the cytoplasm of liver cancer cells by immunohistochemical staining. Conclusions: TPM3 is an interacting partner of GEP and may play an important role in hepatocarcinogenesis. © 2012 Lam et al.published_or_final_versio

A case-controlled comparison of single-site access versus conventional three-port laparoscopic appendectomy

Background: The aim of this study was to compare patients who underwent single-site access laparoscopic appendectomy (SSALA) to those who underwent conventional three-port laparoscopic appendectomy (TPLA) in a case-controlled manner. Methods: Consecutive patients who underwent SSALA for suspected acute appendicitis between April and September 2009 were retrospectively compared to those who underwent TPLA between January and December 2008 in a case-controlled manner. The patients were matched for age, gender, and pathological findings. The main outcome measurements included postoperative recovery, morbidities, and mortalities. Results: During the study period, a total of 30 patients underwent SSALA and these were matched with 60 TPLA patients. There were no significant differences in the mean operative time, hospital stay, and 30-day morbidity rate between the two groups. None of the patients required conversion. Two patients with significant contamination and abscess collection noted during SSALA required a relaparotomy for peritoneal lavage and adhesiolysis due to prolonged ileus. Conclusions: SSALA is feasible and the perioperative outcome was comparable to that of TPLA. However, future prospective studies will need to evaluate whether SSALA can adequately tackle patients with significant peritoneal contamination. © 2010 Springer Science+Business Media, LLC.link_to_subscribed_fulltex

Analysis of Differentially Expressed Genes in Hepatocellular Carcinoma with Hepatitis C Virus by Suppression Subtractive Hybridization

Hepatitis C virus (HCV) infection is associated with pathogenesis of hepatocellular carcinoma (HCC). We carried out suppression subtractive hybridization to identify variable expression of genes linked to HCC with HCV infection. RNA from both tumorous (tester) and nontumorous (driver) liver tissues was isolated. The cDNA clones were subjected to MegaBACE PCR sequencing to identify those that hybridized to the subtracted library with preference. Nucleic acid sequences generated were searched against the human UniGene database. Among 576 clones screened in the tumorous liver tissue, we identified 30 genes and 28 expressed sequence tags (ESTs). Among 30 genes detected, 23 were with known functions and 7 with unknown functions. The known genes identified had diversified functions and could be divided into 10 functional categories. Twenty percent of these genes were previously known to be tumor related and those most frequently appearing were haptoglobin alpha(2FS)-beta precursor, haptoglobin related protein, and alpha-2-macroglobulin. Four out of 30 known genes (immunoglobulin lambda light chain, kappa immunoglobulin, spliceosomal protein, and X-ray repair cross-complementing protein) were related to chromosome translocation and nucleotide repair. These four genes may contribute to carcinogenesis caused by DNA-damaged agents and to the efficiency of anticancer therapy. The genes with unknown function, which were most frequently detected, were PRO2760 and PRO2955; both encode proteins that express in fetal liver. Twenty-one known and six novel genes were discovered in the nontumorous liver tissue. Apparently, these 27 genes were lost in the tumorous liver tissues. Therefore, using suppression subtractive hybridization, we have identified a number of genes associated with HCC with HCV infection. Most of these genes have not been reported in HCC. Further characterization of these differentially expressed known and unknown genes will provide useful information in understanding the genes responsible for the development of HCC.link_to_subscribed_fulltex