Establishment of a primary effusion lymphoma cell line (RM-P1) and in vivo growth system using SCID mice

Primary effusion lymphoma (PEL) is recognized as a unique lymphoma entity, which occurs exclusively in body cavities as a serous lymphomatous effusion without tumor formation or organ infiltration. We established a cell line of B-cell origin from a pericardial effusion of a 63-year-old Japanese PEL patient who did not have human immunodeficiency virus infection. This PEL cell line had human herpesvirus-8 (HHV-8) and Epstein-Barr virus (EBV) infection. We named this cell line RM-P1. This cell line showed complex chromosomal abnormalities that could not be identified by G-banding. However, spectral karyotyping analysis determined the origin and organization of all unidentified chromosomal abnormalities. When inoculated into the peritoneal cavity of 8 severe combined immunodeficiency (SCID) mice depleted of natural killer cells, RM-P1 cells induced solid tumor with ascites in all animals tested. These tumor and ascitic cells had the same immunogenotypic features as those of the original RM-P1. These 2 types of cells were positive for both HHV-8 and EBV as demonstrated using polymerase chain reaction. Fluorescence-activated cell sorting analyses showed that neither tumors nor ascitic cells grown in SCID mice expressed leukocyte function-associated antigen (LFA)-1alpha (CD11a), LFA-1lbeta (CD18), LFA-2 (CD2), LFA-3 (CD58), intercellular adhesion molecule (ICAM)-1 (CD54), ICAM-2 (CD102), ICAM-3 (CD50), or leukocyte endothelial adhesion molecule (LECAM)-1 (CD62L), suggesting that these cytoadhesion molecules are not involved in tumor formation of RM-P1 cells in vivo. The establishment of the RM-P1 cell line and the animal model of PEL may provide insights for understanding the relationship between these viruses and PEL and for understand the mechanism for PEL.     

YCD/5-FC自杀基因治疗系统对K562B白血病细胞杀伤作用的小鼠体内实验研究

目的　了解酵母菌胞嘧啶脱氨酶 5 氟胞嘧啶 (YCD 5 FC)系统在体内对转基因高致瘤性K5 6 2细胞 (K5 6 2B细胞 )的杀伤效应。方法　以高滴度逆转录病毒转染K5 6 2B细胞并筛选出阳性转染克隆YCD K5 6 2B ;12只SCID小鼠分为治疗及对照组 ,在小鼠左右两侧近前肢处腹部皮下注射YCD K5 6 2B及K5 6 2B细胞 ,成瘤后治疗组腹腔注射 5 0 0mg kg 5 FC共 10d ,对照组腹腔注射生理盐水 ,观察瘤体相对体积变化及病理变化。结果　瘤细胞接种第 2 1天 ,瘤体相对体积分别为 :YCD K5 6 2B +5 FC组 2 .92 2± 0 .5 81,YCD K5 6 2B +生理盐水组 2 4.434± 4.790 ,K5 6 2B +5 FC组 2 2 .70 1± 2 35 0 ,K5 6 2B +生理盐水组 2 4.46 0± 1.6 70 ;YCD K5 6 2B +5 FC组与YCD K5 6 2B +生理盐水组相比差异非常显著 (P =0 0 0 0 1) ,K5 6 2B +5 FC组及K5 6 2B +生理盐水组相比 ,差异无显著性 (P =0 .0 96 ) ,表明 5 FC对转YCD基因的K5 6 2B白血病细胞有明显的杀伤效应 ,而对未转基因细胞的生长无影响 ;YCD K5 6 2B +5 FC组瘤体于瘤细胞接种后第 12～第 15天 (5 FC治疗的第 3～第 6天 )有所缩小 (最小的相对体积为 0 .6 81) ,病理检查可见 5 FC治疗组瘤体有以小动脉血管为中心的坏死。结论　YCD 5 FC系统在体内对转YCD     

Functional redundancy between the XLF and DNA-PKcs DNA repair factors in V(D)J recombination and nonhomologous DNA end joining

Classical nonhomologous end joining (C-NHEJ) is a major mammalian DNA double-strand break (DSB) repair pathway that is required for assembly of antigen receptor variable region gene segments by V(D)J recombination. Recombination activating gene endonuclease initiates V(D)J recombination by generating DSBs between two V(D)J coding gene segments and flanking recombination signal sequences (RS), with the two coding ends and two RS ends joined by C-NHEJ to form coding joins and signal joins, respectively. During C-NHEJ, recombination activating gene factor generates two coding ends as covalently sealed hairpins and RS ends as blunt 5′-phosphorylated DSBs. Opening and processing of coding end hairpins before joining by C-NHEJ requires the DNA-dependent protein kinase catalytic subunit (DNA-PKcs). However, C-NHEJ of RS ends, which do not require processing, occurs relatively normally in the absence of DNA-PKcs. The XRCC4-like factor (XLF) is a C-NHEJ component that is not required for C-NHEJ of chromosomal signal joins or coding joins because of functional redundancy with ataxia telangiectasia mutated kinase, a protein that also has some functional overlap with DNA-PKcs in this process. Here, we show that XLF has dramatic functional redundancy with DNA-PKcs in the V(D)J SJ joining process, which is nearly abrogated in their combined absence. Moreover, we show that XLF functionally overlaps with DNA-PKcs in normal mouse development, promotion of genomic stability in mouse fibroblasts, and in IgH class switch recombination in mature B cells. Our findings suggest that DNA-PKcs has fundamental roles in C-NHEJ processes beyond end processing that have been masked by functional overlaps with XLF.     

Temporal lobe epilepsy, depression, and hippocampal volume

Objective:   To evaluate the relationship between hippocampal volume loss, depression, and epilepsy.
Background:   There is a significantly increased incidence of depression and suicide in patients with epilepsy. Both epilepsy and depression are associated with reduced hippocampal volumes, but it is uncertain whether patients with both conditions have greater atrophy than those with epilepsy alone. Previous studies used depression measures strongly weighted to current state, and did not necessarily assess the influence of chronic major depressive disorder (trait), which could have a greater impact on hippocampal volume.
Methods:   Fifty-five epilepsy patients with complex partial seizures (CPS) confirmed by electroencephalography (EEG) had three-dimensional (3D)-spoiled gradient recall (SPGR) acquisition magnetic resonance imaging (MRI) scans for hippocampal volumetric analysis. Depression screening was performed with the Beck Depression Inventory (BDI, 51 patients) and with the structured clinical inventory for DSM-IV (SCID, 34 patients). For the BDI, a score above 10 was considered mild to moderate, above 20 moderate to severe, and above 30 severe depression. MRI and clinical analysis were performed blinded to other data. Statistical analysis was performed with Systat using Student's t test and analysis of variance (ANOVA).
Results:   There was a significant interaction between depression detected on SCID, side of focus, and left hippocampal volume. Patients with a diagnosis of depression and a right temporal seizure focus had significantly lower left hippocampal volume. A similar trend for an effect of depression on right hippocampal volume in patients with a right temporal focus did not reach statistical significance.
Conclusions:   Our results suggest that patients with right temporal lobe epilepsy and depression have hippocampal atrophy that cannot be explained by epilepsy alone.