Malignant glioma is a consistently fatal brain cancer. The tumor invades the surrounding tissue, limiting complete surgical removal and thereby initiating recurrence. Identifying molecules critical for glioma invasion is essential to develop targeted, effective therapies. The expression of astrocyte elevated gene-1 (AEG-1) increases in malignant glioma and AEG-1 regulates in vitro invasion and migration of malignant glioma cells by activating the nuclear factor-KB (NF-KB) signaling pathway. The present studies elucidate the domains of AEG-1 important for mediating its function. Serial NH 2 -terminal and COOH-terminal deletion mutants were constructed and functional analysis revealed that the NH 2 -terminal 71 amino acids were essential for invasion, migration, and NF-KB-activating properties of AEG-1. The p65-interaction domain was identified between amino acids 101 to 205, indicating that p65 interaction alone is not sufficient to mediate AEG-1 function. Coimmunoprecipitation assays revealed that AEG-1 interacts with cyclic AMPresponsive element binding protein-binding protein (CBP), indicating that it might act as a bridging factor between NF-KB, CBP, and the basal transcription machinery. Chromatin immunoprecipitation assays showed that AEG-1 is associated with the NF-KB binding element in the interleukin-8 promoter. Thus, AEG-1 might function as a coactivator for NF-KB, consequently augmenting expression of genes necessary for invasion of glioma cells. In these contexts, AEG-1 represents a viable potential target for the therapy of malignant glioma.

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Stem cells are critical for the maintenance of many tissues, but whether their integrity is maintained in the face of immunity is unclear. Here we found that cycling epithelial stem cells, including Lgr5 intestinal stem cells, as well as ovary and mammary stem cells, were eliminated by activated T cells, but quiescent stem cells in the hair follicle and muscle were resistant to T cell killing. Immune evasion was an intrinsic property of the quiescent stem cells resulting from systemic downregulation of the antigen presentation machinery, including MHC class I and TAP proteins, and is mediated by the transactivator NLRC5. This process was reversed upon stem cell entry into the cell cycle. These studies identify a link between stem cell quiescence, antigen presentation, and immune evasion. As cancer-initiating cells can derive from stem cells, these findings may help explain how the earliest cancer cells evade immune surveillance.

Periventricular leucomalacia has long been investigated as a leading cause of motor and cognitive dysfunction in patients with spastic diplegic cerebral palsy. However, patients with periventricular leucomalacia on conventional magnetic resonance imaging do not always have motor dysfunction and preterm children without neurological abnormalities may have periventricular leucomalacia. In addition, it is uncertain whether descending motor tract or overlying cortical injury is related to motor impairment. To investigate the relationship between motor pathway injury and motor impairment, we conducted voxelwise correlation analysis using tract-based spatial statistics of white matter diffusion anisotropy and voxel-based-morphometry of grey matter injury in patients with periventricular leucomalacia and spastic diplegia (n = 43, mean 12.86 ± 4.79 years, median 12 years). We also evaluated motor cortical and thalamocortical connectivity at resting state in 11 patients using functional magnetic resonance imaging. The functional connectivity results of patients with spastic diplegic cerebral palsy were compared with those of age-matched normal controls. Since γ-aminobutyric acid(A) receptors play an important role in the remodelling process, we measured neuronal γ-aminobutyric acid(A) receptor binding potential with dynamic positron emission tomography scans (n = 27) and compared the binding potential map of the patient group with controls (n = 20). In the current study, white matter volume reduction did not show significant correlation with motor dysfunction. Although fractional anisotropy within most of the major white matter tracts were significantly lower than that of age-matched healthy controls (P < 0.05, family wise error corrected), fractional anisotropy mainly within the bilateral corticospinal tracts and posterior body and isthmus of the corpus callosum showed more significant correlation with motor dysfunction (P < 0.03) than thalamocortical pathways (P < 0.05, family-wise error corrected). Cortical volume of the pre- and post-central gyri and the paracentral lobule tended to be negatively correlated with motor function. The motor cortical connectivity was diminished mainly within the bilateral somatosensory cortex, paracentral lobule, cingulate motor area and visual cortex in the patient group. Thalamovisual connectivity was not diminished despite severe optic radiation injury. γ-Aminobutyric acid(A) receptor binding potential was focally increased within the lower extremity homunculus, cingulate cortex, visual cortex and cerebellum in the patient group (P < 0.05, false discovery rate corrected). In conclusion, descending motor tract injury along with overlying cortical volume reduction and reduced functional connectivity appears to be a leading pathophysiological mechanism of motor dysfunction in patients with periventricular leucomalacia. Increased regional γ-aminobutyric acid(A) receptor binding potential appears to result from a compensatory plasticity response after prenatal brain injury.

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