Analysis of in vitro ADCC and clinical response to trastuzumab: possible relevance of FcγRIIIA/FcγRIIA gene polymorphisms and HER-2 expression levels on breast cancer cell lines.
Analysis of in vitro ADCC and clinical response to trastuzumab: possible relevance of FcγRIIIA/FcγRIIA gene polymorphisms and HER-2 expression levels on breast cancer cell lines.
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DOI：
10.1186/s12967-015-0680-0
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发表时间：
2015-10-08
影响因子：
7.4
通讯作者：
Pistillo MP
中科院分区：
文献类型：
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作者：
Boero S;Morabito A;Banelli B;Cardinali B;Dozin B;Lunardi G;Piccioli P;Lastraioli S;Carosio R;Salvi S;Levaggi A;Poggio F;D'Alonzo A;Romani M;Del Mastro L;Poggi A;Pistillo MP
曲妥珠单抗是一种人源化单克隆抗体（mAb），目前用于治疗HER-2过表达肿瘤亚型的乳腺癌（BC）患者。既往数据报告了FcγRIIIA/IIA基因多态性和/或抗体依赖性细胞毒性（ADCC）与曲妥珠单抗的疗效相关，尽管这些问题的结果仍存在争议。本研究旨在体外评价FcγRIIIA/IIA多态性、ADCC强度和肿瘤靶细胞HER-2表达之间的功能关系，并将其与曲妥珠单抗的应答相关。25例HER-2过表达BC患者在新辅助（NEO）或转移性（MTS）背景下接受曲妥珠单抗治疗，分别通过新开发的焦磷酸测序法和多重Tetra-primer-ARMS PCR对FcγRIIIA 158 V>F和FcγRIIA 131 H>R多态性进行基因分型。在治疗前评价患者外周血单核细胞（PBMC）的曲妥珠单抗介导的ADCC，并使用与曲妥珠单抗反应性水平不同的三种人BC细胞系作为靶标，通过51铬释放进行测量。我们发现，在NEO（P范围分别为0.009 - 0.039和0.007 - 0.047）和MTS（P范围分别为0.009 - 0.032和P = 0.034）患者中，FcγRIIIA 158 F和/或FcγRIIA 131 R变体（通常报告为BC不利）实际上可能表现为ADCC有利基因型。ADCC强度受不同水平的曲妥珠单抗与BC靶细胞反应性的影响。在这种情况下，MCF-7细胞系与曲妥珠单抗的反应性最低，是评价ADCC和曲妥珠单抗应答的最合适细胞系。事实上，我们发现在NEO环境中，显示MCF-7 ADCC的患者频率增加与曲妥珠单抗完全缓解之间存在统计学显著相关性（P = 0.006）。尽管本研究在有限数量的患者中进行，但它表明FcγR基因多态性与BC患者中ADCC程度以及肿瘤靶细胞上HER-2表达水平的相关性。然而，为了证实我们的发现，从更大的BC患者队列中获得的进一步实验证据是强制性的。本文的在线版本（doi：10.1186/s12967-015-0680-0）包含补充材料，可供授权用户使用。
Trastuzumab is a humanized monoclonal antibody (mAb) currently used for the treatment of breast cancer (BC) patients with HER-2 overexpressing tumor subtype. Previous data reported the involvement of FcγRIIIA/IIA gene polymorphisms and/or antibody-dependent cellular cytotoxicity (ADCC) in the therapeutic efficacy of trastuzumab, although results on these issues are still controversial. This study was aimed to evaluate in vitro the functional relationships among FcγRIIIA/IIA polymorphisms, ADCC intensity and HER-2 expression on tumor target cells and to correlate them with response to trastuzumab. Twenty-five patients with HER-2 overexpressing BC, receiving trastuzumab in a neoadjuvant (NEO) or metastatic (MTS) setting, were genotyped for the FcγRIIIA 158V>F and FcγRIIA 131H>R polymorphisms by a newly developed pyrosequencing assay and by multiplex Tetra-primer-ARMS PCR, respectively. Trastuzumab-mediated ADCC of patients’ peripheral blood mononuclear cells (PBMCs) was evaluated prior to therapy and measured by 51Chromium release using as targets three human BC cell lines showing different levels of reactivity with trastuzumab. We found that the FcγRIIIA 158F and/or the FcγRIIA 131R variants, commonly reported as unfavorable in BC, may actually behave as ADCC favorable genotypes, in both the NEO (P ranging from 0.009 to 0.039 and from 0.007 to 0.047, respectively) and MTS (P ranging from 0.009 to 0.032 and P = 0.034, respectively) patients. The ADCC intensity was affected by different levels of trastuzumab reactivity with BC target cells. In this context, the MCF-7 cell line, showing the lowest reactivity with trastuzumab, resulted the most suitable cell line for evaluating ADCC and response to trastuzumab. Indeed, we found a statistically significant correlation between an increased frequency of patients showing ADCC of MCF-7 and complete response to trastuzumab in the NEO setting (P = 0.006). Although this study was performed in a limited number of patients, it would indicate a correlation of FcγR gene polymorphisms to the ADCC extent in combination with the HER-2 expression levels on tumor target cells in BC patients. However, to confirm our findings further experimental evidences obtained from a larger cohort of BC patients are mandatory. The online version of this article (doi:10.1186/s12967-015-0680-0) contains supplementary material, which is available to authorized users.