Establishment of tumor-specific dendritic cell vaccine pulsed by tumor-derived heat shock protein or cell fusion with tumor cells

已有报道表明，树突状细胞与肿瘤细胞的融合细胞可作为含有肿瘤特异性抗原的抗原呈递细胞（antigen-presenting cells, APCs）。一些DC/肿瘤融合细胞的临床试验表明，晚期患者的肿瘤明显消退。本研究采用电融合技术制备融合细胞。在初步研究中，确定了最佳细胞数（1 × 10^6个dc: 1 × 10^6个肿瘤细胞/mL）和校准电压（50 V, 10 sec）。采用ECM2001电融合仪进行细胞融合，荧光显微镜和流式细胞术证实。树突状细胞与肿瘤细胞的融合率与细胞融合电压有关。然而，DC/肿瘤融合细胞的活力随着电压的升高而降低。我们发现细胞融合的最佳电压为200 V。该条件下细胞融合率为6.12%，细胞存活率为68.33%。我们的数据并不优于其他关于dc与肿瘤细胞电融合的报道。DC/肿瘤融合细胞在肿瘤治疗中的实际应用有待进一步研究。另一方面，RCAS1是一种肿瘤相关抗原，可被针对人子宫腺癌细胞系SiSo的22-1-1抗体识别。有报道称RCAS1可抑制多种人类癌细胞系、T细胞、B细胞和NK细胞等表达受体的细胞的生长，并诱导凋亡细胞死亡。因此，采用免疫组织化学方法结合抗RCAS1抗体检测食管鳞状细胞癌患者中RCAS1的表达。多因素分析显示，RCAS1表达是影响食管癌患者预后的独立因素之一。RCAS1的表达与DC和肿瘤浸润淋巴细胞（TIL）的密度有关。阐明肿瘤细胞对免疫细胞的反击机制，建立有效的肿瘤DC治疗方法。少

Some previous reports indicated that fusion cells of DCs and tumor cells could function as antigen-presenting cells (APCs) containing tumor specific antigens. Several clinical trials with DC/Tumor fusion cells demonstrated an obvious tumor regression in patients with advanced stage of disease. In this study, we used electrofusion techniques for producing the fusion cells. In a preliminary study, the optimal cell numbers (1.0x10^6 of DCs : 1.0x10^6 of tumor cells/mL) and alignment voltage (50 V for 10 sec) were determined. Cell fusion was performed using ECM2001 electrofusion apparatus and confirmed by fluorescent microscopy and flow cytometry. The fusion ratio of DCs and tumor cells correlated with the voltage for cell fusion. However, the viability of DC/tumor fusion cells had decreased as the elevation of the voltage. We found that the optimal voltage for cell fusion was 200 V. This condition achieved 6.12 % of fusion ratio and 68.33 % of cell viability. Our data are not superior to … More the other reports for electrofusion of DCs and tumor cells. Further studies are requested for practical use of DC/tumor fusion cells in cancer therapy. On the other hand, RCAS1 is a tumor-associated antigen recognized by 22-1-1 antibody raised against a human uterine adenocarcinoma cell line, SiSo. It has been reported that RCAS1 inhibited the growth of receptor-expressing cells, such as a variety of human cancer cell lines, T, B and NK cells and induced apoptotic cell death. Thus, RCAS1 expression was examined in patients with esophageal squamous cell carcinomas using an immunohistochemical method in conjunction with anti-RCAS1 antibody. Multivariate analyses showed that RCAS1 expression was one of the independent prognostic factors in patients with esophageal cancer. RCAS1 expression was related with the population density of DC and tumor-infiltrating lymphocytes (TIL). The mechanisms of counterattack by tumor cells against immune cells should be clarified to establish an effective DC treatment for cancer. Less