Development of chemoimmunothempy against renal cancer by up-regulation of co-stimulatory molecules

在本研究中，我们观察了阿霉素对人肾癌细胞(RCC)外周血淋巴细胞(PBL)和肿瘤浸润性淋巴细胞(TIL)裂解敏感性的影响。我们还探讨了阿霉素调节肾癌细胞对PBL和TIL敏感性的分子机制。我们发现，用亚毒性浓度的阿霉素预处理肾癌细胞，可增强PBL和TIL的抗癌活性。阿霉素上调肾癌细胞中白细胞功能相关抗原-3(LFA-3)和细胞间黏附分子-1(ICAM-1)的表达。LFA-3和ICAM-1在细胞毒性T淋巴细胞对癌细胞的结合和杀伤中起关键作用。在表阿霉素和吡柔比星两种阿霉素衍生物处理的肾癌细胞中，LFA-3和ICAM-1的表达也有上调。阿霉素进一步增加了PBL与肾癌细胞的结合。此外，阿霉素还可使肾癌细胞对Fas和肿瘤坏死因子相关的凋亡诱导配体(TRAIL)介导的细胞毒作用敏感。这些结果提示，小剂量阿霉素治疗可使肾癌细胞对PBL和TIL的杀伤增敏，有望成为治疗耐药和/或免疫耐药肾细胞癌的一种新的免疫治疗手段。阿霉素诱导的LFA-3和ICAM-1可能与增强人肾癌细胞对PBL和TIL的敏感性有关。在利用TRAIL受体2(TRAIL-R2)激动型抗体Lexatumab开展分子靶向治疗的实验中，我们证实了阿霉素和Lexatumab对肾癌细胞的协同杀伤作用。我们进一步证明来昔单抗和阿霉素的协同细胞毒作用是通过诱导TRAIL-R2和内在caspase途径诱导细胞凋亡来实现的。

In this study, we investigated the effect of adriamycin on the susceptibility of human renal cell carcinoma (RCC) cells to lysis by peripheral blood lymphocytes (PBL) and tumor infiltrating lymphocytes (TIL). We also explored molecular mechanisms involved in adriamycin modulating susceptibility of RCC cells to PBL and TIL. We found that pretreatment of RCC cells with subtoxic concentrations of adriamycin resulted in a potentiation of anticancer activities of PBL and TIL. Adriamycin up-regulated leukocyte function-associated antigen-3 (LFA-3) and intercellular adhesion molecule-1 (ICAM-1) expressions in RCC cells. LFA-3 and ICAM-1 are critical in the binding and killing of cytotoxic T lymphocytes against cancer cells. Up-regulation of LFA-3 and ICAM-1 was also observed in RCC cells treated with two derivatives of adriamycin, epirubicin and pirarubicin. Adriamycin further significantly increased the bindings of PBL to RCC cells. In addition, adriamycin sensitized RCC cells to Fas- and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-mediated cytotoxicity. These findings suggest that treatment of RCC patients with low doses of adriamycin may sensitize the RCC cells to killing by PBL and TIL, and may be a novel immunotherapeutic modality for the treatment of drug-resistant and/or immune-resistant RCC. The induction of LFA-3 and ICAM-1 by adriamycin may involve in the enhancement of susceptibility of PBL and TIL-mediated cytolysis in human RCC cells. In the experiments of developing molecular targeted therapy using Lexatumumab, an agonistic TRAIL-receptor 2 (TRAIL-R2) antibody, we demonstrated synergistic cytotoxic effect of adriamycin and Lexatumumab against RCC cells. We further demonstrated that the synergistic cytotoxicity of Lexatumumab and adriamycin was realized by inducing apoptosis through the induction of TRAIL-R2 and the intrinsic caspase pathway.