Transplantation of neuronal cells induced from human mesenchymal stem cells improves neurological functions after stroke without cell fusion

The options for treating stroke are limited, but stem cells hold promise as a therapy because of their multipotency. Neuronal cells derived from mesenchymal stem cells (MSC) were reported to have more therapeutic effect than MSCs. For elucidating the therapeutic mechanism of neuronal cells, here we generated a model of focal cerebral infarction by performing left common carotid artery occlusion in adult gerbils. We transfected human trabecular bone-derived MSCs (hMSCs) with the Notch intracellular domain to induce their differentiation into neuronal cells (hN-MSCs). These cells were stereotaxically transplanted into the local ischemic hemisphere 4 days after the occlusion. Behavioral analyses were conducted 28 days after transplantation, and then fluorescence in situ hybridization (FISH) and a histological evaluation were performed. Histologically, transplanted cells were distributed around the periinfarct region, and approximately 8.5% and 4.2% of hN-MSCs and hMSCs survived, respectively; 53.2% ± 9.6% of hN-MSCs were microtubule-associated protein 2(+) (MAP-2(+) ) and extended neurites, whereas only 0.9% ± 0.3% of hMSCs were MAP-2(+) . In FISH, human nucleus-specific signals were detected in both hN-MSCs and hMSCs grafted brains, but no transplanted cell had a merged gerbil-specific nuclear signals. hN-MSC-transplanted animals showed significantly better recovery than animals given control vehicle in the T-maze, bilateral asymmetry, and open field tests. These findings suggested that hN-MSCs have greater therapeutic potential than hMSCs for stroke and that cell fusion does not primarily contribute to the therapeutic mechanism of MSC transplantation.     

Aurora kinase B is a predictive factor for the aggressive recurrence of hepatocellular carcinoma after curative hepatectomy

Background:

Patterns of cancer recurrence hold the key to prognosis after curative resection. This retrospective study aimed to identify a predictor and therapeutic candidate for aggressive recurrence of hepatocellular carcinoma (HCC).

Methods:

Primary HCC tissues from 107 patients who had curative resection were analysed. Genome‐wide gene expression profiles were investigated using a microarray technique, and clustering analysis was carried out based on the first diagnosis of recurrence according to the Milan criteria. Immunohistochemical expression and array‐based comparative genomic hybridization (array‐CGH) were also assessed.

Results:

Microarray analysis revealed overexpression of Aurora kinase B, a chromosome passenger protein kinase, as the most significant predictor of the aggressive recurrence of HCC. Aurora kinase B protein expression was significantly associated with aggressive recurrence (P < 0·001) and prognosis (P < 0·001). Multivariable analysis identified Aurora kinase B as the only independent predictor of aggressive recurrence of HCC (P = 0·031). Array‐CGH analysis showed that genomic instability was closely related to Aurora kinase B expression (P = 0·011).

Conclusion:

Aurora kinase B is an effective predictor of aggressive HCC recurrence, in relation to the genomic instability. It might be worth considering as a molecular target for the adjuvant therapy of HCC. Copyright © 2008 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.     

BCL2L2 is a probable target for novel 14q11.2 amplification detected in a non-small cell lung cancer cell line

Amplification of chromosomal DNA is thought to be one of the mechanisms that activates cancer-related genes in tumors. In a previous genome-wide screening of DNA copy number aberrations in a panel of non-small cell lung cancer (NSCLC) cell lines using an in-house bacterial artificial chromosome-based array, we identified a novel amplification at 14q11.2 in HUT29 cells derived from human lung adenocarcinoma. To identify the most likely target for the 14q11.2 amplification, we determined the extent of the amplicon by fluorescence in situ hybridization and then analyzed NSCLC cell lines for the expression levels of 28 genes present within the 1-Mb amplified region. Significant overexpression in the HUT29 cell line with amplification, relatively frequent overexpression in additional NSCLC cell lines compared with an immortalized normal lung epithelial cell line, and reported information about the function of each candidate gene prompted us to characterize the BCL2-like2 (BCL2L2) gene, a prosurvival member of the BCL2 family, as the most likely target for the 14q11.2 amplicon. Immunohistochemical analysis of 61 primary cases of lung adenocarcinoma demonstrated that BCL2L2 overexpression was significantly associated with tumor stage and differentiation status, and tended to be associated with a poorer prognosis. Downregulation of BCL2L2 expression using small interfering RNA dramatically inhibited the growth of HUT29 cells, but showed no effect on anticancer reagent-induced cell death of the same cell line. These findings demonstrate that overexpressed BCL2L2, through amplification or other mechanisms, promotes the growth of NSCLC, especially the adenocarcinoma subtype, and might be a therapeutic target.     

The incidence of hypoplasia of the corpus callosum in patients with dup (X)(q28) involving MECP2 is associated with the location of distal breakpoints

Duplications of Xq28 harboring the methyl CpG binding protein 2 (MECP2) gene explain approximately 1% of X-linked intellectual disability (XLID). The common clinical features observed in patients with dup(X)(q28) are severe ID, infantile hypotonia, mild dysmorphic features and a history of recurrent infections, and MECP2 duplication syndrome is now recognized as a clinical entity. While some patients with this syndrome have other characteristic phenotypes, the reason for the spectrum of phenotypes has not been clarified. Since dup(X)(q28) rearrangements vary in size and location, genes other than MECP2 might affect the phenotype. We used a high-density oligonucleotide array to carry out precise mapping in eight Japanese families in which dup(X)(q28) was detected using an in-house bacterial artificial chromosome-based microarray to screen cohorts of individuals with multiple congenital anomalies and intellectual disability (MCA/ID) or with XLID. We hypothesized that the size, gene content, and location of dup(X)(q28) may contribute to variable expressively observed in MECP2 duplication syndrome. Genotype-phenotype correlation in our cases together with cases reported in the literature suggested that copy-number gains between two low copy repeats (LCRK1 and LCRL1) are associated with the incidence of hypoplasia of the corpus callosum. Further studies are necessary to understand the mechanism of this association.