Shellfish are a common cause of adverse food reactions in hypersensitive individuals and shrimp is one of the most frequently reported causes of allergic reactions. A novel allergen from Penaeus monodon, designated Pen m 2, was identified by two-dimensional immunoblotting using sera from subjects with shrimp allergy, followed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry analysis of the peptide digest. This novel allergen was then cloned and the amino acid sequence deduced from the cDNA sequence. The cloned cDNA encoded a 356-aa protein with an acetylated N terminus at Ala2, identified by postsource decay analysis. Comparison of the Pen m 2 sequence with known protein sequences revealed extensive similarity with arginine kinase (EC 2.7.3.3) from crustaceans. Pen m 2 was purified by anion exchange chromatography and shown to have arginine kinase activity and to react with serum IgE from shrimp allergic patients and induce immediate type skin reactions in sensitized patients. Using Pen m 2-specific antisera and polyclonal sera from shrimp-sensitive subjects in a competitive ELISA inhibition assay, Pen m 2 was identified as a novel cross-reactive Crustacea allergen. This novel allergen could be useful in allergy diagnosis and in the treatment of Crustacea-derived allergic disorders.

Understanding the mechanism by which cell growth, migration, polyploidy, and tumourigenesis are regulated may provide important therapeutic strategies for cancer therapy. Here we identify the Skp2-macroH2A1 (mH2A1)-CDK8 axis as a critical pathway for these processes, and deregulation of this pathway is associated with human breast cancer progression and patient survival outcome. We showed that mH2A1 is a new substrate of Skp2 SCF complex whose degradation by Skp2 promotes CDK8 gene and protein expression. Strikingly, breast tumour suppression upon Skp2 deficiency can be rescued by mH2A1 knockdown or CDK8 restoration using mouse tumour models. We further show that CDK8 regulates p27 protein expression by facilitating Skp2-mediated p27 ubiquitination and degradation. Our study establishes a critical role of Skp2-mH2A1-CDK8 axis in breast cancer development and targeting this pathway offers a promising strategy for breast cancer therapy.

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death throughout the world. Although hepatitis B or C viral infections are main risk factors for HCC, the molecular mechanisms leading to HCC formation have not been clarified. To reduce the mortality and improve the effectiveness of therapy, it is important to search for changes in tumor-specific biomarkers whose function may involve in disease progression and which may be useful as potential therapeutic targets. In this study, we employed two-dimensional difference gel electrophoresis (2D-DIGE) combined with nano flow liquid chromatography tandem mass spectrometry (nanoLC-MS/MS) to investigate differentially expressed proteins in HCC. For each of eight HCC patients, Cy3-labeled proteins isolated from tumor tissue were combined with Cy5-labeled proteins isolated from the surrounding nontumor tissue and separated by 2D gel electrophoresis along with a Cy2-labeled mixture of all tumor and nontumor samples as an internal standard. Thirty-four protein spots corresponding to 30 different proteins were identified by nanoLC-MS/MS as showing significant change (paired t-test, p< 0.05) in the level of expression between tumor and nontumor tissues. Sixteen proteins were up-regulated and 14 were down-regulated in HCC; they seem to play important roles in a variety of pathways including glycolysis, fatty acid transport and trafficking, amino acid metabolism, iron and xenobiotic metabolism, ethanol metabolism, cell cycle regulation, cytoskeleton, and stress. A remarkable finding is the up-regulation of 14-3-3gamma protein in HCC. 14-3-3 isoforms had been linked to carcinogenesis because they are involved in various cellular processes such as cell cycle regulation, apoptosis, proliferation, and differentiation. In conclusion, 2D-DIGE is an efficient strategy that enables us to identify differentially expressed proteins in HCC. Identification of potential biomarkers, such as the pinpointing of 14-3-3gamma in our findings, may provide further useful insights into the pathogenesis of HCC.

Although the significant risk factors for hepatocellular carcinoma (HCC) are well known from epidemiological studies, diagnosis of this disease at an early stage is difficult, and HCC remains one of the leading causes of cancer death worldwide. Thus, to identify any useful HCC-related biomarkers is still a need. We performed SELDI-TOF MS to identify differentially expressed proteins in HCC serum using weak cation exchange protein chips. Protein characterization was performed by 2-DE separation and nano flow LC-MS/MS. A total of 55 sera were collected from HCC patients and compared with those from 48 patients with chronic hepatitis and 9 healthy individuals. A candidate marker of about 8900 Da was detected as differentially expressed in patients with chronic hepatitis C and hepatitis C virus (HCV)-related HCC. We identified this differentially expressed protein as complement C3a. The expression of C3a in HCC sera was further validated by PS20 chip immunoassay and Western blotting. Complement C3a was found to be elevated in patients with chronic hepatitis C and HCV-related HCC. The combination of SELDI-TOF MS and 2-DE provides a solution to identify disease-associated serum biomarkers.