Blocking of methionine aminopeptidase-2 by TNP-470 induces apoptosis and increases chemosensitivity of cholangiocarcinoma

Context: Resistance of cancer cells to chemotherapeutic drugs is a major pitfall of the failure of chemotherapy treatment for cholangiocarcinoma (CCA). A new therapeutic strategy that can improve treatment efficacy is mandatory for CCA patients. Our previous findings demonstrated the overexpression of methionine aminopeptidase-2 (MetAP2) in CCA patients. In addition, supplementation of TNP-470, a MetAP2 inhibitor, significantly inhibited the growth and metastatic activities of CCA cell lines. However, the molecular mechanism of antitumor activity of TNP-470 and the synergistic antitumor activity of TNP-470 combined with chemotherapeutic drugs are still unknown. Aims: The aim of this study is to evaluate the molecular mechanism of anticancer activity and the potential use of TNP-470 as a chemosensitizing agent in CCA cell lines. Materials and Methods: Cell cycle and apoptosis of CCA cell lines were evaluated using flow cytometry with propidium iodide staining. Expression of apoptosis regulatory proteins was measured by Western blotting. The chemosensitizing effect of TNP-470 was determined using combination index. Results: TNP-470 inhibited the growth of CCA cells via induction of apoptosis through activation of the p38-phosphorylation and up- and down-regulation of Bax and Bcl-xL, respectively. Furthermore, TNP-470 significantly enhanced the antitumor activity of 5-fluorouracil, cisplatin, doxorubicin, and gemcitabine. Conclusions: The present results show that TNP-470 could be a potential therapeutic or adjuvant agent for CCA

Evaluation of human IgG subclass antibodies in the serodiagnosis of Paragonimiasis heterotremus.

Immunoglobulin G subclass antibodies (IgG1, IgG2, IgG3, and IgG4) responses to the excretory-secretory antigens of the lung fluke, Paragonimus heterotremus, were analyzed using the immunoblotting technique in an attempt to further improve the sensitivity and specificity for serodiagnosis of human paragonimiasis. Serum samples from patients with proven paragonimiasis, from patients with other parasitic infections, pulmonary tuberculosis and from healthy counterparts were analyzed. The results indicate that immunoblotting for the detection of IgG4 antibodies to an excretory-secretory product of P. heterotremus of an approximate molecular mass of 31.5 kDa, is the most reliable test. It gives accuracy, sensitivity, specificity, and positive and negative predictive values of 97.6%, 100%, 96.9%, 90% and 100%, respectively.

Evaluation of polymerase chain reaction, conventional and MRSA screen latex agglutination methods for detection of methicillin-resistant, -borderline and -susceptible Staphylococcus aureus.

Methicillin-resistant Staphylococcus aureus (MRSA), is difficult and expensive to treat, therefore early screening is essential. Several phenotypic and genotypic methods are used to detect MRSA; however, the method of choice remains problematic. We have evaluated four phenotypic methods, broth microdilution (MIC), oxacillin disk agar diffusion (ODD), oxacillin screening salt agar (OSS), and a new rapid phenotypic (MRSA screen latex agglutination, MSLA) with the genotypic gold standard of PCR mecA detection to determine the most appropriate method for routine laboratory use. We randomly collected 203 S. aureus isolates from patients and carriers at two hospitals in Thailand. Using MIC method, three sub-groups were differentiated from among these isolates, namely MRSA (106 isolates), borderline-resistant S. aureus (BRSA) (65 isolates), and methicillin-susceptible S. aureus (MSSA)(32 isolates). A total of 10 methicillin-resistant S. epidermidis (MRSE) isolates were also included. The sensitivity and specificity of MIC, ODD, OSS, and MSLA were 99 and 96, 100 and 97, 100 and 97, and 100 and 100%, respectively. Our study indicated that ODD is still appropriate for routine laboratory. MSLA had the highest sensitivity and specificity and is rapid but expensive, so is the most appropriate method for emergency cases. MIC method was better for BRSA detection and OSS method was more appropriate for screening clinical specimens and carriers.

Immunodiagnosis of human fascioliasis using an antigen of Fasciola gigantica adult worm with the molecular mass of 27 kDa by a dot-ELISA.

Immunodominant antigens of an approximate molecular mass of 27 kDa (FG 27) were obtained from an excretory-secretory product of adult Fasciola gigantica by a simple continuous-elution method. A dot-ELISA using the FG 27 antigen was developed for the detection of specific antibodies from patients infected with F. gigantica. Control sera were obtained from patients with other parasitic infections and healthy volunteers. The accuracy, sensitivity, specificity, and positive and negative predictive values were 98.2%, 100%, 97.4%, 76.9% and 100%, respectively. This dot-ELISA is a specific, sensitive and easy to perform method for the rapid diagnosis of fascioliasis, particularly when more complex laboratory tests are unavailable.