The matrix-degrading metalloproteinases （MMPs）, particularly MMP-9, play important roles in the pathogenesis and development of malignant gliomas. In the present study, the oncogenic role of MMP-9 in malignant glioma cells was investigated via antisense RNA blockade in vitro and in vivo. TJ905 malignant glioma cells were transfected with pcDNA3.0 vector expressing antisense MMP-9 RNA （pcDNA-AS-MMP9）, which significantly decreased MMP-9 expression, and cell proliferation was assessed. For in vivo studies, U251 cells, a human malignant glioma cell line, were implanted subcutaneously into 4-to 6-week-old BALB/c nude mice. The mice bearing well-established U251 gliomas were treated with intratumoral pcDNA-AS-MMP9-Lipofectamine complex （AS-MMP-9-treated group）, subcutaneous injection of endostatin （endostatin-treated group）, or both （combined therapy group）. Mice treated with pcDNA （empty vector）-Lipofectamine served as the control group. Four or eight weeks later, the volume and weight of tumor, MMP-9 expression, microvessel density and proliferative activity were assayed. We demonstrate that pcDNA-AS-MMP9 significantly decreased MMP-9 expression and inhibited glioma cell proliferation. Volume and weight of tumor, MMP-9 expression, microvessel density and proliferative activity in the antisense-MMP-9-treated and therapeutic alliance groups were significantly lower than those in the control group. The results suggest that MMP-9 not only promotes malignant glioma cell invasiveness, but also affects tumor cell proliferation. Blocking the expression of MMP-9 with antisense RNA substantially suppresses the malignant phenotype of glioma cells, and thus can be used as an effective therapeutic strategy for malignant gliomas.
Objective To evaluate the frequency, distribution and clinical significance of the antibodies to the fetal and/or adult acetylcholine receptor （AChR） in patients with myasthenia gravis （MG）. Methods AChR antibodies were detected by cell-based assay in the serum of ocular MG （OMG） （n = 90） and generalized MG （GMG） patients （n = 110）. The fetal-type （2α： β： γ： δ） and adult-type （2α： β： ε： δ） AChR were used as antigens, and their relevance to disease presentation was assessed. Results The overall frequencies of anti-adult and anti-fetal AChR antibodies were similar in all 200 patients examined, with 14 having serum specific to the AChR-γ subunit, and 22 to the AChR-ε subunit. The overall sensitivity when using the fetal and adult AChR antibodies was higher than that when using the fetal AChR antibody only （P = 0.015）. Compared with OMG patients, the mean age at disease onset and the positive ratio of antibodies to both isoforms of the AChR were significantly higher in patients who subsequently progressed to GMG. Older patients and patients with both anti-fetal and anti-adult AChR antibodies had a greater risk for developing generalized disease [odds ratio （OR）, 1.03; 95% confidence interval （CI）, 1.01–1.06 and OR, 5.09; 95% CI, 2.23–11.62]. Conclusion Using both fetal-and adult-type AChRs as the antigens may be more sensitive than using either subtype. Patients with serum specific to both isoforms are at a greater risk of progressing to GMG. Patients with disease onset at an advanced age appear to have a higher frequency of GMG conversion.
Qi-Guang ShiZhi-Hong WangXiao-Wei MaDa-Qi ZhangChun-Sheng YangFu-Dong ShiLi Yang
