NYESO-1/LAGE-1s and PRAME Are Targets for Antigen Specific T Cells in Chondrosarcoma following Treatment with 5-Aza-2-Deoxycitabine

BackgroundChondrosarcoma has no proven systemic option in the metastatic setting. The development of a non-cross-resistant strategy, such as cellular immunotherapy using antigen-specific T cells would be highly desirable. NY-ESO-1 and PRAME are members of the Cancer Testis Antigen (CTA) family that have been identified as promising targets for T cell therapy. LAGE-1 is a cancer testis antigen 90% homologous to NY-ESO-1, sharing the 157–165 A*0201 NY-ESO-1 epitope with its transcript variant, LAGE-1s. A number of CTA's have been induced using 5-Aza-2-Deoxycitabine (5-Aza-dC) in other cancers. We sought to evaluate the feasibility of targeting chondrosarcoma tumors using NY-ESO-1/LAGE-1s and PRAME specific T cells using 5-Aza-dC to induce antigen expression.
MethodsWe used 11 flash frozen tumors from the University of Washington tumor bank to test for the expression of NY-ESO-1, PRAME, LAGE-1s and LAGE-1L in chondrosarcoma tumors. Using four chondrosarcoma cell lines we tested the expression of these CTA's with and without 5-Aza-dC treatments. Finally, using NY-ESO-1/LAGE-1s and PRAME specific effectors that we generated from sarcoma patients, we evaluated the ability of these T cells to lyse A*0201 expressing chondrosarcoma cell lines in vitro both with and without 5-Aza-dC treatment.
ResultsA minority (36%) of chondrosarcoma tumors expressed either NY-ESO-1 or LAGE-1s at >10% of our reference value and none expressed PRAME at that level. However, in all four of the chondrosarcoma cell lines tested, NY-ESO-1 and PRAME expression could be induced following treatment with 5-Aza-dC including in cell lines where expression was absent or barely detectable. Furthermore, NY-ESO-1/LAGE-1s and PRAME specific CD8+ effector T cells were able to specifically recognize and lyse A*0201 expressing chondrosarcoma cell lines following 5-Aza-dC treatment.
ConclusionThese data suggest that adoptive immunotherapy in combination with 5-Aza-dC may be a potential strategy to treat unresectable or metastatic chondrosarcoma patients where no proven systemic therapies exist.

【背景】目前对于转移性软骨肉瘤，尚无获批的系统性治疗方案。开发无交叉耐药的治疗策略（如采用抗原特异性T细胞的细胞免疫治疗）具有极高的临床需求。NY-ESO-1与PRAME均属于癌睾丸抗原（Cancer Testis Antigen, CTA）家族，已被鉴定为T细胞治疗的潜在靶点。LAGE-1是一种癌睾丸抗原，与NY-ESO-1同源性达90%，其转录变体LAGE-1s共享NY-ESO-1的157-165位A*0201限制性表位。已有研究表明，在其他癌种中可通过5-氮杂-2'-脱氧胞苷（5-Aza-2-Deoxycitabine, 5-Aza-dC）诱导多种癌睾丸抗原表达。本研究旨在评估采用5-Aza-dC诱导抗原表达后，靶向NY-ESO-1/LAGE-1s与PRAME的特异性T细胞治疗软骨肉瘤的可行性。
【方法】我们使用华盛顿大学肿瘤库中的11例速冻软骨肉瘤标本，检测其中NY-ESO-1、PRAME、LAGE-1s及LAGE-1L的表达水平。我们采用4株软骨肉瘤细胞系，检测经5-Aza-dC处理前后上述癌睾丸抗原的表达情况。最后，利用我们从肉瘤患者体内分离得到的NY-ESO-1/LAGE-1s与PRAME特异性效应细胞，评估经5-Aza-dC处理前后，这些T细胞体外裂解表达A*0201的软骨肉瘤细胞系的能力。
【结果】仅36%的软骨肉瘤肿瘤标本中，NY-ESO-1或LAGE-1s的表达量高于参考值的10%，且无一例标本的PRAME表达达到该水平。但在所有4株受试软骨肉瘤细胞系中，经5-Aza-dC处理后均可诱导NY-ESO-1与PRAME的表达，包括原本表达缺失或几乎无法检测的细胞系。此外，经5-Aza-dC处理后，NY-ESO-1/LAGE-1s与PRAME特异性CD8+效应T细胞可特异性识别并裂解表达A*0201的软骨肉瘤细胞系。
【结论】本研究数据提示，过继免疫治疗联合5-Aza-dC或可成为治疗不可切除或转移性软骨肉瘤的潜在策略——这类患者目前尚无获批的系统性治疗方案。