Associations between epidermal growth factor receptor gene mutation and serum tumor markers in advanced lung adenocarcinomas: a retrospective study / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the associations between epidermal growth factor receptor (EGFR) gene mutations and serum tumor markers in advanced lung adenocarcinomas.</p><p><b>METHODS</b>We investigated the association between EGFR gene mutations and clinical features, including serum tumor marker levels, in 97 advanced lung adenocarcinomas patients who did not undergo the treatment of EGFR tyrosine kinase inhibitors. EGFR gene mutation was detected by real-time PCR at exons 18, 19, 20, and 21. Serum tumor marker concentrations were analyzed by chemiluminescence assay kit at the same time.</p><p><b>RESULTS</b>EGFR gene mutations were detected in 42 (43%) advanced lung adenocarcinoma patients. Gender (P=0.003), smoking status (P=0.001), and abnormal serum status of carcinoembryonic antigen (CEA, P=0.028) were significantly associated with EGFR gene mutation incidence. Multivariate analysis showed the abnormal CEA level in serum was independently associated with the incidence of EGFR gene mutation (P=0.046) with an odds ratio of 2.613 (95% CI: 1.018-6.710). However, receiver operating characteristic (ROC) curve analysis revealed CEA was not an ideal predictive marker for EGFR gene mutation status in advanced lung adenocarcinoma (the area under the ROC curve was 0.608, P=0.069).</p><p><b>CONCLUSIONS</b>EGFR gene mutation status is significantly associated with serum CEA status in advanced lung adenocarcinmoas. However, serum CEA is not an ideal predictor for EGFR mutation.</p>

Effect of rapamycin on apoptosis in human myelodysplastic syndrome cell line MUTZ-1 and its possible mechanisms / 中国实验血液学杂志

The aim of this study was to investigate the effect of rapamycin on cell growth and apoptosis in the myelodysplastic syndrome (MDS) cell line MUTZ-1 and possible mechanism. MUTZ-1 cells were treated with rapamycin, cell proliferation capability was determined with MTT, protein expression including Annexin V/PI, caspase 3, PTEN, p-Akt, p-mTOR and the cell cycle were analyzed with flow cytometry. The results indicated that the proliferation of MUTZ-1 cells was inhibited by rapamycin in concentration-and time-dependent manners (r=0.67, 0.61, 0.72). After treatment with rapamycin for 24-72 hours, cell count in G0/G1 were significantly higher than that of the control (p<0.01), and this effect showed a time-and concentration-dependency (r=0.94, 0.93, 0.92), the cell cycle was blocked in G0/G1 phase. As compared with control group, the proportion of Annexin V+PI-MUTZ-1 cells and the cellular PTEN levels increased in the treated group dramatically and in time-and dose-dependent manners (p<0.01). To the contrary, level of p-mTOR expression markedly decreased as compared with control group (p<0.05). It is concluded that the rapamycin inhibits the proliferation of MUTZ-1 cells, down-regulates the PTEN/PI3K-Akt/mTOR signaling pathway by interaction with mTOR, which induces the apoptosis of mUTZ-1 cells.

Preparation and application of antibody against staphylococcal enterotoxin C2 / 药学学报

The filtrate of Staphylococcus aureus culture has been used in an ampule form named as staphylococcal enterotoxin C injection for cancer therapy in clinic for ten years in China and proved to be effective. The active constituent of three kinds of injections is claimed to be staphylococcal enterotoxin C2 (SEC2), and the content of SEC2 is used as quality control. However, the correct content of SEC2 was not known and the relative amount of SEC2 was very low because of the complicated components of the filtrate. In this research, we established a proper ELISA system for the detection of SEC2 in staphylococcal enterotoxin C injection, which will improve the quality control of the injection. We produced and identified polyclonal and monoclonal antibodies of SEC2 and established BA-ELISA method based on the method of sandwich ELISA. It was found that the BA-ELISA method had good specificity, sensitivity and reproducibility, and being able to detect SEC2 at concentration from 2 to 20 ng x mL(-1), with an average CV value of 5.08%. The SEC2 content in staphylococcal enterotoxin C injection was calculated. There is some difference between the actual and labeled contents in the injections.

Expression and bioactivity of the cloned staphylococcal enterotoxin O / 药学学报

This study is to clone the gene of staphylococcal enterotoxins O, obtain recombinant protein (rSEO) and investigate its activity on mice lymphocyte. Staphylococcus aureus O gene is cloned into GST gene fusion vector pGEX-4T-1. The resultant plasmid pGEX-4T-SEO was used to transform E. coLi BL21, where the GST-SEO fusion protein was expressed efficiently. Then SEO was purified by Glutathione Sepharose 4B affinity column and digested with thrombin. The bioactivity of SEO was analyzed by MTT assay on mice lymphocyte and tumor cells. The nucleotide sequence was confirmed to code for the protein correctly, and soluble SEO was expressed efficiently in E. coli BL21 with pGEX-4T-SEO. The protein purified by affinity chromatography resulted to be one single band by SDS-PAGE detection. The MTT assay of the purified rSEO demonstrated that its abilities of stimulating T cells and inhibiting the proliferation of K562, K562-ADM and B16 cells were equivalent to that of SEC in vitro. The expression plasmid pGEX-4T-SEO was constructed and the recombinant superantigen was expressed successfully, which may provide a foundation for the further research of the anticancer activity of SEO.

Expression and bioactivity analysis of staphylococcal enterotoxin C2 / 药学学报

<p><b>AIM</b>To clone the gene of staphylococcal enterotoxin C2 and express it in the form of a soluble fusion protein in E. coli. Then the activation of SEC2 on mice lymphocyte and its lethal effects on tumor cells were studied.</p><p><b>METHODS</b>Staphylococcus aureus SEC2 gene was cloned into GST gene fusion vector pGEX-4T-1. The resultant plasmid pGEX-4T-SEC2 was used to transform E. coli BL21, where the GST-SEC2 fusion protein was expressed efficiently. The rSEC2 protein was purified with Glutathione Sepharose 4B affinity column and digested with thrombin. The in vitro culture system was utilized to observe the activation of the SEC2 on mice lymphocyte and the lethal effects on tumor cells of the activated mice lymphocyte.</p><p><b>RESULTS</b>The proper gene of SEC2 was cloned and purified rSEC2 was obtained. The MTT results indicated that rSEC2 have strong ability to stimulate mice lymphocyte to proliferate with a dose-dependent manner. With the proliferation of mice splenic lymphocyte, rSEC2 has a strong lethal effect on tumor cells B16, K562 and K562-AD.</p><p><b>CONCLUSION</b>In this study, the gene of SEC2 was cloned and the rSEC2 protein was obtained, which had strong lethal effect on tumor cells B16, K562 and K562-AD.</p>