Kimura T, Takeshima H, Nomiyama N, Nishi T, Kino T, Kochi M, Kuratsu J-I, Ushio Y
Department of Neurosurgery, Kumamoto University School of Medicine, Kumamoto 860-8556, Japan.
Int J Oncol. 2002 Oct;21(4):707-15. doi: 10.3892/ijo.21.4.707.
Lymphocytes are frequently observed in human malignant glioma, the mechanism(s) underlying their appearance is not fully understood. To clarify tumor immunity in malignant gliomas, we analyzed the expression of 8 novel lymphocyte-specific chemokines in human glioma cell lines and glioma tissues by RT-PCR, Northern blot, immunoblot and immunohistochemistry, and examined the correlation with the infiltration of various subsets of lymphocytes. For the 8 chemokines examined (LARC, TARC, ELC, SLC, PARC, LEC, HCC-2, and SCM-1alpha), expression of LARC was clearly detectable in all 12 glioma cell lines by RT-PCR. Additionally, expression of TARC and SCM-1alpha was detectable in the majority of glioma cell lines. However, the expression level of most chemokines was low, so that Northern blot analysis could not demonstrate their expression with the exception of LARC in 2 cell lines. Expression of LARC mRNA and LARC protein was strongly induced by phorbol myristate ester in U87 MG cells. The production of LARC protein was demonstrated in 4 of 8 glioblastoma tissues by immunoblotting, and 9 of 33 samples (27.3%) by immunohistochemistry. Interestingly, the positivity of LARC staining was significantly correlated with the infiltration of CD8-, CD4-, and CD45R0-positive cells (p<0.001). Although the constitutive expression level of LARC is low, certain stimulations could strongly induce its expression, and play a crucial role in the tumor immunity of human malignant glioma.
淋巴细胞在人类恶性胶质瘤中经常被观察到，但其出现的潜在机制尚未完全明了。为了阐明恶性胶质瘤中的肿瘤免疫，我们通过逆转录聚合酶链反应（RT-PCR）、Northern印迹、免疫印迹和免疫组织化学分析了8种新型淋巴细胞特异性趋化因子在人类胶质瘤细胞系和胶质瘤组织中的表达，并检测了其与各种淋巴细胞亚群浸润的相关性。对于所检测的8种趋化因子（LARC、TARC、ELC、SLC、PARC、LEC、HCC-2和SCM-1α），通过RT-PCR在所有12种胶质瘤细胞系中均能明显检测到LARC的表达。此外，在大多数胶质瘤细胞系中可检测到TARC和SCM-1α的表达。然而，大多数趋化因子的表达水平较低，以至于除了在2种细胞系中能检测到LARC外，Northern印迹分析无法显示它们的表达。佛波酯在U87 MG细胞中强烈诱导LARC mRNA和LARC蛋白的表达。通过免疫印迹在8例胶质母细胞瘤组织中的4例中证实了LARC蛋白的产生，通过免疫组织化学在33个样本中的9例（27.3%）中证实了LARC蛋白的产生。有趣的是，LARC染色阳性与CD8、CD4和CD45R0阳性细胞的浸润显著相关（p<0.001）。尽管LARC的组成性表达水平较低，但某些刺激可强烈诱导其表达，并在人类恶性胶质瘤的肿瘤免疫中起关键作用。
