Sakurai Fuminori, Fujiwara Toshiyoshi, Mizuguchi Hiroyuki
Laboratory of Biochemistry and Molecular Biology, Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan.
Yakugaku Zasshi. 2013;133(3):291-6. doi: 10.1248/yakushi.12-00237-1.
An easy and sensitive detection method for circulating tumor cells (CTC) is expected to be developed because CTC are a promising biomarker for early diagnosis of tumors and prognosis prediction of tumor patients. Our group has already developed a CTC detection method using a conditionally replicating adenovirus (Ad) which efficiently replicates and expresses GFP in telomerase-positive tumor cells. However, malignant tumor cells express much low levels of coxsackievirus and adenovirus receptor (CAR), leading to inefficient infection with a conventional conditionally replicating Ad. In addition, a tiny fraction of normal blood cells, including lymphocytes, express GFP following infection. To overcome these problems, we have developed a next-generation conditionally replicating Ad. The next-generation conditionally replicating Ad possesses the fiber protein derived from Ad serotype 35, leading to efficient infection in both CAR-positive and -negative tumor cells, because the fiber protein of Ad serotype 35 binds to CD46, which is expressed on almost all human cells. Furthermore, sequences complementary to blood cell-specific miRNA (miR-142-3p) were inserted into the 3' untranslated region of the E1 gene and GFP gene, leading to the suppression of GFP expression in normal blood cells. In this symposium, we will not only introduce the importance of CTC as a biomarker and conventional CTC detection methods but also show our data of the novel CTC detection using the next-generation conditionally replicating Ad.
循环肿瘤细胞（CTC）有望开发出一种简便且灵敏的检测方法，因为CTC是肿瘤早期诊断和肿瘤患者预后预测的一种很有前景的生物标志物。我们团队已经开发出一种利用条件性复制腺病毒（Ad）的CTC检测方法，该腺病毒能在端粒酶阳性肿瘤细胞中高效复制并表达绿色荧光蛋白（GFP）。然而，恶性肿瘤细胞表达的柯萨奇病毒和腺病毒受体（CAR）水平很低，导致传统的条件性复制腺病毒感染效率低下。此外，一小部分正常血细胞，包括淋巴细胞，在感染后会表达GFP。为克服这些问题，我们开发了一种新一代条件性复制腺病毒。新一代条件性复制腺病毒具有源自35型腺病毒血清型的纤维蛋白，能在CAR阳性和阴性肿瘤细胞中高效感染，因为35型腺病毒血清型的纤维蛋白可与几乎所有人类细胞上表达的CD46结合。此外，与血细胞特异性微小RNA（miR-142-3p）互补的序列被插入到E1基因和GFP基因的3'非翻译区，从而抑制正常血细胞中GFP的表达。在本次研讨会上，我们不仅将介绍CTC作为生物标志物的重要性以及传统的CTC检测方法，还将展示我们使用新一代条件性复制腺病毒进行新型CTC检测的数据。
