IDH mutations predict longer survival and response to temozolomide in secondary glioblastoma.

Recent studies have shown that isocitrate dehydrogenase 1/2 (IDH1/2) mutations occur frequently in secondary glioblastoma. This study aimed to investigate their impact on temozolomide chemosensitivity and relationship with O(6)-methylguanine DNA methyltransferase (MGMT) promoter methylation in secondary glioblastoma. Searches for IDH1 and IDH2 mutations, 1p19q codeletion, MGMT promoter methylation, and p53 expression were carried out in a series of 86 secondary glioblastomas and correlated with progression-free survival and overall survival. Response to temozolomide was evaluated by progression-free survival, as well as by tumor size on successive MRI scans, then correlated with molecular alterations. IDH (IDH1 or IDH2) mutations were found in 58/79 patients (73.4%). IDH mutation, MGMT promoter methylation, and 1p19q codeletion were associated with prolonged progression-free survival in univariate (P < 0.001, P < 0.001, P = 0.003, respectively) and multivariate analysis (P < 0.001, P < 0.001, P = 0.035, respectively). IDH mutation (P = 0.001) and MGMT promoter methylation (P = 0.011) were correlated with a higher rate of objective response to temozolomide. Further analysis of response to temozolomide showed that patients with both IDH mutation and MGMT promoter methylation had the best response rate to temozolomide. IDH mutation appears to be a significant marker of positive chemosensitivity in secondary glioblastoma. Use of IDH status combined with MGMT promoter status as a stratification factor seems appropriate in future clinical trials involving temozolomide for the treatment of patients with secondary glioblastoma.

Optimization and staining characteristic of immunohistochemical methods in detecting isocitrate dehydrogenase-1 mutations in human gliomas / 中华神经医学杂志

Objective To compare the advantages and disadvantages of different immunohistochemical methods in detecting isocitrate dehydrogenase-1 (IDH 1) mutations in gliomas,and to optimize the processes these detection.Methods One hundred and thirty-eighty glioma specimens,collected and conformed by pathology in our hospital from January 2013 to December 2013,were used in our study,including 18 of WHO grade Ⅰ,49 of WHO grade Ⅱ,24 of WHO grade Ⅲ and 47 of WHO grade Ⅳ.Manual immunohistochemical method and automatic immunohistochemical instrument were used to detect the IDH1 mutation.PCR-high resolution melting curve analysis (PCR-HRM) was used to verify the above results.Results There were 65.9％ positive specimens those had IDH1 positive tumor cells higher than 75％,and 70.7％ positive specimens those were strong staining.Manual immunohistochemical method enjoyed advantages as clean background,clearness and easy reading,and no interpretation difficulty or false-positive result were noted with this method;while automatic immunohistochemical instrument enjoyed dark background,which led to interpretation difficulty or false-positive result;the results of IDH1 staining had significant differences between and automatic immunohistochemical instrument (x2=22.042,P=0.000).The positive detection rate of automatic immunohistochemical instrument was significantly higher than that of manual immunohistochemical method,and the results of IDH1 detection had no significant difference between manual immunohistochemical method and PCR-HRM (x2=0.800,P=0.371).Conclusions The results of IDH1 detection by manual immunohistochemical method are more accurate than that of immunohistochemical instrument.IDH1 gene mutation only has a relationship with the number of positive tumor cells,and not the staining intensity.The specimen can be considered to IDH1 gene mutation when the positive cells are more than 5％.

Expression of miR-200a in colorectal carcinoma cell lines and its effect on LoVo cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To detect miR-200a expression in human colorectal carcinnoma (CRC) cell lines and explore the role of miR-200a in regulating the biological behavior of CRC cells.</p><p><b>METHODS</b>Real-time quantitative RT-PCR (qRT-PCR) was used to detect miR-200a expression levels in 6 CRC cell lines (HCT116, HT29, LS174T, SW480, SW620 and LoVo). miR-200a mimics were transiently transfected into LoVo, and the changes in cell proliferation, apoptosis, migration, and cell-cell adhesion were assessed using CCK-8 assay, TUNEL assay, transwell migration assay, and homogenous adhesion experiment, respectively.</p><p><b>RESULTS</b>The expression of miR-200a was down-regulated in the 6 CRC cell lines, among which the highly metastatic LoVo cell line showed the lowest expression and the tumorigenic but non-metastatic CRC cell line HCT116 had the highest expression. Overexpression of miR-200a depressed cell proliferation and migration but promoted cell apoptosis and cell-cell adhesion in LoVo cells.</p><p><b>CONCLUSION</b>miR-200a plays a role in regulating the invasiveness and metastasis of CRC, and overexpression of miR-200a causes a significant reduction of cell proliferation and migration and promotes apoptosis and cell-cell adhesion in LoVo cells.</p>

Establishment and preliminary evaluation of a rapid detection method for germ tube-specific antigens of Candida albicans / 中华皮肤科杂志

Objective To establish a double-antibody sandwich enzyme linked immunosorbent assay (DAS-ELISA) for the rapid detection of germ tube-specific antigens of Candida albicans,and to evaluate its specificity and sensitivity.Methods A DAS-ELISA was established with the monoclonal antibody McAb03.2C1-C2 as the primary antibody,and horseradish peroxidase (HRP) labeled McAb03.2C1-C2 as the secondary antibody.The established assay was used to detect germ tube-specific antigens of Candida albicans in sera from 5 patients with systemic Candida albicans infection and from 6 rabbit models at 12,24,48,72hours,on week 1,2 after infection with Candida albicans.Results A good liner relationship was observed between the absorbance value at 495 nm and antigen concentrations when the titer of McAb03.2C1-C2 was 1 ∶ 4000 and the concentration of coated antigen varied from 1.25 to 40 μg/ml.The specificity and sensitivity of the DAS-ELISA were 95％ and 92％ respectively in the detection of germ tube-specific antigens in the rabbit models.The results of detection with DAS-ELISA in serum specimens from the patients were consistent with those with the routine method.Conclusions A DAS-ELISA is primarily established for the rapid detection of germ tube-specific antigens of Candida albicans,and has shown a satisfactory sensitivity and specificity in the animal model experiment.

Expression of CD4~+CD25~+ regulatory T cells in colorectal cancer patients and its significance / 中国癌症杂志

Background and purpose:CD4+CD25+ regulatory T (Treg) cells are an important naturally accruing subpopulation of regulatory T cells. They not only prevent the spontaneous emergence of autoimmune diseases and contribute to the establishment of dominant tolerance on allogeneic transplantation, but also play an essential role in the generation, development and immunotherapy of many different kinds of malignant tumors. We studied the expression of CD4+CD25+ regulatory T cells(Tregs) in colorectal cancer patients and its significance. Methods:The tissues of tumors and counterpart normal tissue of 30 colorectal cancer patients were collected, the proportion of CD4+CD25+ Tregs as the percentage of the total CD4+ T cells were analyzed using flow cytometry and immunohistochemistry.Results:Compared with counterpart normal tissue(5.5?1.3)%, the percentage of CD4+CD25+ Tregs in tumor tissues was significantly higher (24.1?4.8)%(t=5.155,P=0.002). The proportion of CD4+CD25+ Tregs in the patients with lymph nodes metastasis was (27.9?3.6)% which was significantly higher than that in patients without lymph nodes metastasis[(20.3?1.3)% (t=3.489,P=0.025)].Conclusions:The proportion of CD4+CD25+ Tregs in tumor tissues of colorectal cancer patients was significantly increased, and they may play an essential role in the development of colorectal cancer.