Vaccine and radiation for the therapy of human cancers

~（153）Sm-EDTMP对肿瘤细胞表型的调控作用 细胞并增强T细胞介导的杀伤。将人类肿瘤细胞暴露于亚致死剂量的 外照射上调肿瘤抗原和辅助分子的表达， 使肿瘤细胞更容易被抗原特异性细胞毒性T淋巴细胞杀死 （CTL）。这项研究探讨了接触姑息剂量的 放射性药物可以改变肿瘤细胞的表型，使它们变得更 易受T细胞介导的杀伤。在此，10个人肿瘤细胞系（4个前列腺，2个乳腺， 和4个肺）暴露于增加剂量的放射性药物钐-153- 乙二胺四亚甲基膦酸盐（153 Sm-EDTMP）用于癌症患者治疗疼痛 因为骨转移荧光活化细胞分选分析和定量 五种表面分子表达的实时聚合酶链反应（PCR）分析 并进行了前列腺癌相关抗原的研究。LNCaP人 前列腺癌细胞暴露于153 Sm-EDTMP，并与肿瘤相关的 抗原特异性CTL杀伤试验，以确定暴露于153 Sm-EDTMP是否 使LNCaP细胞对T细胞介导的杀伤更敏感。肿瘤细胞上调了 表面分子Fas（100%的细胞系上调Fas），癌胚抗原（90%）， 粘蛋白-1（60%）、主要组织相容性复合体（MHC）I类（50%）和细胞间 粘附分子-1（40%）对153 Sm-EDTMP有反应。定量实时PCR分析 显示了额外的上调的肿瘤抗原。~（153）Sm-EDTMP对LNCaP细胞的作用 更易被前列腺特异性抗原、癌胚抗原特异性CTL杀伤 抗原（CEA）和粘蛋白-1。153 Sm-EDTMP的剂量相当于提供给 骨改变肿瘤细胞的表型，表明153 Sm-EDTMP可能协同作用 用免疫疗法增加肿瘤细胞对CTL杀伤的敏感性。使用 放射性标记的单克隆抗体，以增强疫苗介导的T细胞应答。放射标记 单克隆抗体（mAb）已在血液学中显示出可测量的抗肿瘤作用， 恶性肿瘤。对于实体瘤来说，这种结果更难实现，因为 大部分是由于难以将足够量的mAb递送至肿瘤块。 以前的研究表明，非裂解水平的外部束辐射可以使肿瘤 细胞更容易受到T细胞介导的杀伤。这些研究的目的是确定 如果将放射性标记的mAb选择性递送至肿瘤将调节肿瘤细胞表型 从而增强疫苗介导的T细胞杀伤。在这里，人CEA转基因小鼠被 用表达CEA的鼠癌细胞系移植。放射免疫治疗包括 钇-90（Y-90）标记的抗CEA mAb，单独使用或与疫苗联合使用 疗法单剂量Y-90标记的抗CEA mAb与疫苗治疗联合， 结果表明，与对照组相比， 疫苗或单克隆抗体单独;这被证明是由Fas/Fas配体的参与介导的 通路接受联合治疗的小鼠也显示出在免疫应答方面的显著增加。 与单独的疫苗相比，活的肿瘤浸润CEA特异性CD 8 + T细胞的百分比。 治愈肿瘤的小鼠表现出抗原级联反应，导致CD 4+和CD 8 + T细胞 不仅对CEA有反应，而且对p53和gp 70也有反应。这些结果表明，系统 放射性标记的mAb形式的放射治疗与疫苗组合，促进有效的 抗肿瘤反应，这可能对未来临床试验的设计产生影响。

The use of chelated radionuclide (Samarium-153-EDTMP) to modulate phenotype of tumor cells and enhance T-cell-mediated killing. Exposing human tumor cells to sublethal doses of external beam radiation upregulates expression of tumor antigen and accessory molecules, rendering tumor cells more susceptible to killing by antigen-specific cytotoxic T lymphocytes (CTLs). This study explored the possibility that exposure to palliative doses of a radiopharmaceutical agent could alter the phenotype of tumor cells to render them more susceptible to T-ell-mediated killing. Here, 10 human tumor cell lines (4 prostate, 2 breast, and 4 lung) were exposed to increasing doses of the radiopharmaceutical samarium-153- ethylenediaminetetramethylenephosphonate (153Sm-EDTMP) used in cancer patients to treat pain due to bone metastasis. Fluorescence-activated cell sorting analysis and quantitative real-time polymerase chain reaction (PCR) analysis for expression of five surface molecules and several tumor-associated antigens involved in prostate cancer were done. LNCaP human prostate cancer cells were exposed to153Sm-EDTMPand incubated with tumor-associated antigen-specific CTL in a CTL killing assay to determine whether exposure to 153Sm-EDTMP rendered LNCaP cells more susceptible to T-cell-mediated killing. Tumor cells up-regulated the surface molecules Fas (100% of cell lines upregulated Fas), carcinoembryonic antigen (90%), mucin-1 (60%), major histocompatibility complex (MHC) class I (50%), and intercellular adhesion molecule-1 (40%) in response to 153Sm-EDTMP. Quantitative real-time PCR analysis revealed additional upregulated tumor antigens. Exposure to 153Sm-EDTMP rendered LNCaP cells more susceptible to killing by CTLs specific for prostate-specific antigen, carcinoembryonic antigen (CEA), and mucin-1. Doses of 153Sm-EDTMP equivalent to palliative doses delivered to bone alter the phenotype of tumor cells, suggesting that 153Sm-EDTMP may work synergistically with immunotherapy to increase the susceptibility of tumor cells to CTL killing. The use of radiolabeled monoclonal antibody to enhance vaccine-mediated T-cell responses. Radiolabeled monoclonal antibodies (mAb) have demonstrated measurable antitumor effects in hematologic malignancies. This outcome has been more difficult to achieve for solid tumors due, for the most part, to difficulties in delivering sufficient quantities of mAb to the tumor mass. Previous studies have shown that nonlytic levels of external beam radiation can render tumor cells more susceptible to T cell-mediated killing. The goal of these studies was to determine if the selective delivery of a radiolabeled mAb to tumors would modulate tumor cell phenotype so as to enhance vaccine-mediated T-cell killing. Here, mice transgenic for human CEA were transplanted with a CEA expressing murine carcinoma cell line. Radioimmunotherapy consisted of yttrium-90 (Y-90)-labeled anti-CEA mAb, used either alone or in combination with vaccine therapy. A single dose of Y-90-labeled anti-CEA mAb, in combination with vaccine therapy, resulted in a statistically significant increase in survival in tumor-bearing mice over vaccine or mAb alone; this was shown to be mediated by engagement of the Fas/Fas ligand pathway. Mice receiving the combination therapy also showed a significant increase in the percentage of viable tumor-infiltrating CEA-specific CD8+ T cells compared to vaccine alone. Mice cured of tumors demonstrated an antigen cascade resulting in CD4+ and CD8+ T-cell responses not only for CEA, but for p53 and gp70. These results show that systemic radiotherapy in the form of radiolabeled mAb, in combination with vaccine, promotes effective antitumor response, which may have implications in the design of future clinical trials.