EGFR/EGFRvIII remodels the cytoskeleton via epigenetic silencing of AJAP1 in glioma cells

EGFR amplification and mutations are the most common oncogenic events in GBM. EGFR overexpression correlates with GBM invasion, but the underlying mechanisms are poorly understood. In a previous study, we showed that AJAP1 is involved in regulating F-actin to inhibit the invasive ability of GBM. In addition, in a GBM cell line, the AJAP1 promoter was highly bound by H3K27me3 and, through bioinformatics analysis, we found that AJAP1 expression was negatively correlated with EGFR. In this study, we found that the pathway downstream of EGFR had a higher activation level in GBM cell lines, which led to excessive tumor suppressor silencing. Therefore, we deduced that in glioma cells, the pathway downstream of EGFR remodels the cytoskeleton via AJAP1 epigenetic silencing to enhance invasion. Furthermore, MK2206 reversed AJAP1 downregulation by inhibiting the EGFR pathway. In vivo, MK2206 also inhibited the proliferation and local invasion of 87-EGFRvIII. These data suggest that activation of the EGFR signal transduction pathway genetically silences anti-oncogenes to enhance GBM malignancy. MK2206 might be a promising therapeutic for EGFR/EGFRvIII-positive GBMs.

A new caryolane sesquiterpene from Heteropappus altaicus (Willd.) Novopokr

A new caryolane sesquiterpene, 1β-methoxycaryol-9-one (1), along with eight known compounds (2-9), was isolated from the whole plant of Heteropappus altaicus. The structures were elucidated on the basis of comprehensive 1D- and 2D-NMR analysis and high-resolution mass spectrometry. The 13C-NMR data of compound 2 are reported for the first time.

[Studies of the mixoploid variation in banana micropropagated plants]

A special type of variation--the mixoploid variation, which had a great effect on the variation in the production of banana vitroplants, was reported for the first time. By means of examining chromosome, isozymes (EST, MDH, POX) and endogenous hormones (iPAs, IAA), the varied characters of the mixoploid varianties during the propagation in vitro when cultured as explant were investigated. The rate of the chromosome aberration in cells was characterized by starting at a much higher level and rising more rapidly in the preceding 15 subcultures as compared with the control. The rate of the isozyme variation was higher obviously than that of the control. The plantlets cloned in vitro from the mixoploid variant were also studied. The experiment showed that both the variant rates of chromosome and phenotype rose obviously. The mixoploid variant can cause the rate of variation to rise during the micropropagation.

[Autopsy study of 100 elderly patients]

Clinical and autopsy records of 100 elderly patients were analyzed. The most common cause of death in this series was malignant tumors (39%). The second leading cause of death was diseases of the circulatory system (37%), in which cerebrovascular accident alone accounted for 21%. Cor pulmonale and myocardial infarction were also common causes of death. In addition, infective diseases, especially pneumonia and septicemia were often fatal to elderly patients. The discrepancy between clinical and post-mortem diagnoses in this series was 24.7%. The causes of incorrect and missed diagnoses are discussed. The results suggest that extensive autoptic study still has vital practical significance.