Magnetic resonance imaging of sequelae of central pontine myelinolysis in chronic alcohol abusers

Central pontine myelinolysis (CPM) is one of the serious neurological complications of alcoholism. This study evaluated magnetic resonance images of sequelae of CPM. Approximately 600 alcoholic patients were examined by a 1.0-T magnetic resonance imaging device, and 11 patients were retrospectively found to have a central pontine lesion, a presumed sequela of CPM. The lesions had various shapes and most were cavitary. In 3 of the 11 patients bilateral symmetrical oval lesions were faintly visible in the middle cerebellar peduncles. These middle cerebellar peduncular lesions were diagnosed as having Wallerian degeneration of the pontocerebellar tract secondary to CPM.     

RPL6/Taxreb107在胃癌耐药细胞系SGC7901/ADR中的差异表达及其与MDR相关性的初步研究

目的 探讨BPL6／Taxreb107在胃癌耐药细胞系SGC7901／ADR与胃癌细胞系SGC7901的差异表达,以及与胃癌多药耐药(MDR)的相关性。方法 提取SGC7901和SGC7901/ADR细胞系总RNA;采用内对照RT-PCR检测RPL6基因和Northem杂交、基因克隆与表达、真核表达载体的构建;以电穿孔法基因转染;以流式细胞仪检测瞬时转染细胞的阿霉素蓄积和潴留。结果 内对照RT-PCR和Northern杂交证实RPL6/Taxreb 107在SGC7901/ADR中高表达。将PCR产物克隆人pUCm-T载体并经测序证实。构建正义和反义真核表达载体(pcDNA3．1)并经酶切鉴定证实后,以电穿孔法将正义真核表达载体转入SGC7901,反义真核表达载体转入SGC7901／ADR。转染48h后检测转染细胞的阿霉素蓄积和潴留,结果提示RPI6／Taxreb107转入细胞后对细胞的耐药性有影响。结论 BPI6／Taxreb107在耐药胃癌细胞中高表达,对胃癌的MDR有影响。     

补肾、健脾、益气、活血法对衰老细胞周期基因表达的调控作用

目的：比较补肾、健脾、益气、活血法对衰老细胞周期基因表达的调控作用。方法：采用上述4种不同的含药血清对衰老的人胚肺二倍体成纤维细胞2Bs细胞株进行处理,通过细胞寿命实验、流式细胞仪、RT—PCR、Westemblot方法研究不同中药对衰老细胞周期及其相关基因(P16^INK4、Cyclin D1及PCNA)的mRNA转录和蛋白表达的影响。结果：补肾、益气中药对衰老细胞周期有一定的促进作用,并可下调衰老细胞增殖抑制基因P16和周期蛋白Cyclin D1的mRNA／蛋白表达;上调细胞周期促进增殖基因PCNAmRNA／蛋白的表达。而健脾、活血中药对细胞周期及其相关基因和蛋白表达的作用不明显。结论：补肾、益气方药对细胞周期有促进作用,其中的作用可能是通过促进P16途径的基因表达来实现。     

Gene therapy for experimental brain tumors using a xenogenic cell line engineered to secrete hIL-2

Summary Local delivery of cytokines has been shown to have a potent anti-tumor activity against a wide range of malignant brain tumors. In this study, we examined the feasibility and efficacy of using a rat endothelial cell line (NTC-121) transfected with the human interleukin-2 (IL-2) gene in treating experimental murine CNS tumors. The NTC-121 cells were injected intracranially in C57BL/6 mice (N = 10/group) along with non-irradiated, non-transfected B16/F10 (wild type) melanoma cells. Sixty percent of mice treated with IL-2 (p<0.001 vs. control) were long-term survivors (LTS) of >120 days. Control animals that received only wild type cells had a median survival of 18 days (range 15–20). Histopathological examination of brains from animals sacrificed at different times showed no tumor growth in the non-irradiated NTC-121 group, moderate (1–2 mm) tumor growth in the irradiated group, and gross tumor invasion (>2 mm) and tissue necrosis in the control group. Moreover, animals treated with IL-2 showed an accumulation of CD8+ T cells around the site of the injected tumor. The use of a xenogenic cell line to deliver hIL-2 stimulates a strong immunologic cytotoxic anti-tumor response that leads to significant prolongation of survival in mice challenged with the B16/F10 intracranial melanoma tumor. Our findings demonstrate that the use of a xenogenic cell line can provide a potent vehicle for the delivery of gene therapy and may therefore represent a new approach for brain tumor therapy.     

Interspecies contamination of the KM3 cell line: implications for CD63 function in melanoma metastasis

CD63 is a member of the tetraspanin superfamily of membrane glycoproteins that has been hypothesised to provide a structural network in the organisation of large multimolecular microdomains at cell membranes. Detailed analyses of the role of CD63 in these complexes through mutagenic studies have been limited, however, by the ubiquitous cellular expression of CD63 in vivo and in vitro. In an attempt to define CD63-null cell lines, we have analysed the expression of CD63 and other tetraspanins on a panel of human cancer cell lines. Similar expression patterns were seen between cell lines from melanomas, breast cancers and prostate cancers. The melanoma cell line KM3, however, described previously as a CD63-null human cell line, was found to express none of the 7 human tetraspanins tested. KM3 was identified definitively as a rat cell line by analysis of karyotype and antigen expression. Notably, KM3 was found to express the rat homologue of CD63. Conclusions concerning the function of human CD63 drawn from studies using KM3 cells therefore require re-evaluation as does the frequently cited hypothesis that CD63 expression is linked to melanoma progression. As KM3 is the only cell line thus far identified as CD63 negative, these results highlight the necessity for the production of a CD63 null system.     

M-CSF targeting into LCL nucleus behaves as a malignancy promotor

Objective: To investigate the functions of nM-CSF in malignant cells. Methods: recombinant M-CSF was targeted into cell nucleus by employing a eukaryotic expression plasmid vector pCMV/myc/nuc. The constructed plasmid was transfected into cells of EBV transformed lymphoblastoid cell line (LCL). RT-PCR, Western blot and immunofluorescent staining showed that recombinant M-CSF was localized into LCL cell nucleus. The transgenic cells showed elevated proliferation potential, enhanced resistance to apoptosis and increased ability of in vitro migration. Conclusion: Nucleus presenting M-CSF might act as a promoting factor in the processes of cellmalignancy.     

骨肉瘤细胞体外培养中仿血管发生现象

目的 对骨肉瘤肿瘤血管产生机制进行初步的研究,观察骨肉瘤细胞是否有仿血管发生的能力。方法 应用Ⅰ型胶原蛋白凝胶的三维培养基对骨肉瘤细胞进行培养,观察骨肉瘤细胞在三维培养基中是否可形成血管样结构,并运用电镜、光镜观察这些血管样结构的形态学构成。结果 电镜、光镜下观察到骨肉瘤细胞在Ⅰ型胶原蛋白凝胶的三维培养基中能够形成血管样结构。结论 骨肉瘤细胞体外能够自身形成血管样结构,具有仿血管发生的能力。     

Synergistic induction of apoptosis by the combination of trail and chemotherapy in chemoresistant ovarian cancer cells

OBJECTIVES: The aim of this study was to investigate whether TNF-related apoptosis-inducing ligand (TRAIL) alone or in combination with chemotherapy could induce apoptosis in ovarian cancer cells resistant to chemotherapy. METHODS: Twelve chemoresistant epithelial cancer cell lines were treated with each chemotherapeutic drug alone (cisplatin, doxorubicin, or paclitaxel), TRAIL alone, or the combination. Toxicity was assessed using the MTS assay. To assess whether growth inhibition was due to apoptosis, TUNEL assay, caspase activation (measured by caspase-3 and PARP cleavage), and the sub G0/G1 fraction of cells were measured. Synergism was confirmed by fractional inhibition and dose-effect analysis. Expression of death and decoy receptors was studied by immunoblotting and an RNase protection assay. Statistical comparison of means was performed using Student's t test. RESULTS: The majority of the chemoresistant cells were also resistant to TRAIL alone. In contrast, the combination of TRAIL and chemotherapy resulted in a significant growth inhibition over a wide range of concentrations. This interaction was synergistic by dose-effect analysis. Flow cytometry demonstrated a significant increase in the fraction of apoptotic cells by the combination compared to each reagent alone. A significant enhancement in caspase and PARP cleavage was observed upon treatment with the combination. Finally, no correlation between induction of apoptosis and level of death receptors was found. CONCLUSIONS: The data suggest that almost all the ovarian cancer cells, which are resistant to chemotherapy, are also resistant to TRAIL. The combination of TRAIL and chemotherapy overcomes this resistance in a synergistic fashion by triggering caspase-mediated apoptosis. The combination of TRAIL and chemotherapy could be useful as a therapy for chemoresistant ovarian cancers.