Development of the Gene-missile therapy against human malignant gliomas using monocyte as a carrier.

人类单核细胞趋化蛋白-1受体被命名为hCCR2，是人类免疫缺陷病毒进入细胞所必需的辅助受体，也是单核细胞趋化蛋白-1的受体，单核细胞趋化蛋白-1是C-C趋化因子家族的成员，介导单核细胞趋化。为了阐明hCCR2转录调控的分子机制，我们克隆并测序了hCCR2基因，全长约8kb，由三个外显子和两个内含子组成。在5‘-侧翼区，存在典型的哺乳动物启动子共同元件，即CAAT盒和TATA盒，导致了单一的转录起始点。此外，我们还发现了成簇的组织特异性顺式调控元件，如GATA共识序列、Oct-1结合序列和CAAT/增强子结合蛋白结合序列。不同启动子缺失的荧光素酶分析和凝胶迁移率改变分析表明，THP-1细胞的基础活性需要三个位于-89到118区域的顺式调控元件。其中一个元件是TATA盒上游36-bp的八聚体序列；它主要与Oct-1结合，并能够增加转录活性。另外两个元件是CAAT/增强子结合蛋白家族的串联识别位点，位于5‘-非翻译区，解释了hCCR2的转录激活和组织特异性。

The human monocyte chemoattractant protein-1 receptor designated hCCR2 is an essential co-receptor in cell entry by the human immunodeficiency virus as well as a receptor for monocyte chemoattractant protein-1, a member of the family of C-C chemokines that mediate monocyte chemotaxis. To elucidate the molecular mechanisms underlying the transcriptional regulation of hCCR2, we cloned and sequenced the hCCR2 gene ; it was approximately 8 kb in length and consisted of three exons divided by two introns. In the 5'-flanking region, there were the typical mammalian promoter consensus elements, a CAAT box and a TATA box, resulting in a single transcription initiation site. In addition, we found clustered tissue-specific cis-regulatory elements such as GATA consensus sequences, Oct-1 binding sequences, and CAAT/enhancer-binding protein binding sequences. Luciferase assays with various promoter deletions and gel mobility shift assays indicated that three cis-regulatory elements located within the region from -89 to +118 are required for basal activity in THP-1 cells. One element is an octamer sequence 36-bp upstream from the TATA box ; it binds mainly to Oct-1 and is capable of increasing transcriptional activity. The other two elements, which are tandem recognition sites of the CAAT/enhancer-binding protein family, are located in the 5'-untranslated region and account for the transcriptional activation as well as the tissue specificity of hCCR2.