肿瘤微环境中黑色素瘤的相互作用遗传损伤:定义可行的治疗方法。
Interacting Genetic Lesions of Melanoma in the Tumor Microenvironment: Defining a Viable Therapy.
机构信息
Human Oncology and Pathogenesis Program, Ludwig Collaborative and Swim Across America Laboratory, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
Department of Medicine, Division of Hematology and Medical Oncology, Weill Cornell Medicine, New York, NY, USA.
出版信息
Adv Exp Med Biol. 2021;1350:123-143. doi: 10.1007/978-3-030-83282-7_6.
Melanoma is the most aggressive form of skin cancer with an estimated 106,110 newly diagnosed cases in the United States of America in 2021 leading to an approximated 7180 melanoma-induced deaths. Cancer typically arises from an accumulation of somatic mutations and can be associated with mutagenic or carcinogenic exposure. A key characteristic of melanoma is the extensive somatic mutation rate of 16.8 mutations/Mb, which is largely attributed to UV exposure. Bearing the highest mutational load, many of them occur in key driver pathways, most commonly the BRAFV600E in the mitogen-activated protein kinase (MAPK) pathway. This driver mutation is targeted clinically with FDA-approved therapies using small molecule inhibitors of oncogenic BRAFV600E and MEK, which has greatly expanded therapeutic intervention following a melanoma diagnosis. Up until 2011, therapeutic options for metastatic melanoma were limited, and treatment typically fell under the spectrum of surgery, radiotherapy, and chemotherapy.Attributed to the extensive mutation rate, as well as having the highest number of neoepitopes, melanoma is deemed to be extremely immunogenic. However, despite this highly immunogenic nature, melanoma is notorious for inducing an immunosuppressive microenvironment which can be relieved by checkpoint inhibitor therapy. The two molecules currently approved clinically are ipilimumab and nivolumab, which target the molecules CTLA-4 and PD-1, respectively.A plethora of immunomodulatory molecules exist, many with redundant functions. Additionally, these molecules are expressed not only by immune cells but also by tumor cells within the tumor microenvironment. Tumor profiling of these cell surface checkpoint molecules is necessary to optimize a clinical response. The presence of immunomodulatory molecules in melanoma, using data from The Cancer Genome Atlas and validation of expression in two model systems, human melanoma tissues and patient-derived melanoma cells, revealed that the expression levels of B and T lymphocyte attenuator (BTLA), TIM1, and CD226, concurrently with the BRAFV600E mutation status, significantly dictated overall survival in melanoma patients. These molecules, along with herpesvirus entry mediator (HVEM) and CD160, two molecules that are a part of the HVEM/BTLA/CD160 axis, had a higher expression in human melanoma tissues when compared to normal skin melanocytes and have unique roles to play in T cell activation. New links are being uncovered between the expression of immunomodulatory molecules and the BRAFV600E genetic lesion in melanoma. Small molecule inhibitors of the MAPK pathway regulate the surface expression of this multifaceted molecule, making BTLA a promising target for immuno-oncology to be targeted in combination with small molecule inhibitors, potentially alleviating T regulatory cell activation and improving patient prognosis.
黑色素瘤是最具侵袭性的皮肤癌,据估计,2021 年美国有 106110 例新诊断病例,导致约 7180 例黑色素瘤相关死亡。癌症通常源于体细胞突变的积累,并且可能与诱变或致癌暴露有关。黑色素瘤的一个关键特征是其广泛的体细胞突变率为 16.8 个突变/Mb,这主要归因于 UV 暴露。由于携带最高的突变负荷,其中许多发生在关键驱动途径中,最常见的是丝裂原激活蛋白激酶(MAPK)途径中的 BRAFV600E。该驱动突变在临床上通过 FDA 批准的使用致癌 BRAFV600E 和 MEK 的小分子抑制剂的疗法进行靶向治疗,这大大扩展了黑色素瘤诊断后的治疗干预。直到 2011 年,转移性黑色素瘤的治疗选择有限,治疗通常属于手术、放疗和化疗的范围。由于广泛的突变率以及具有最高数量的新表位,黑色素瘤被认为是极其免疫原性的。然而,尽管具有这种高度免疫原性,但黑色素瘤以诱导免疫抑制微环境而臭名昭著,这种微环境可以通过检查点抑制剂治疗来缓解。目前临床上批准的两种分子是伊匹单抗和尼伏单抗,它们分别针对 CTLA-4 和 PD-1 分子。存在大量的免疫调节分子,其中许多具有冗余功能。此外,这些分子不仅在肿瘤细胞中表达,而且在肿瘤微环境中的肿瘤细胞中也表达。对这些细胞表面检查点分子进行肿瘤分析对于优化临床反应是必要的。黑色素瘤中免疫调节分子的存在,使用来自癌症基因组图谱的数据并在两个模型系统(人类黑色素瘤组织和患者来源的黑色素瘤细胞)中验证表达,显示 B 和 T 淋巴细胞衰减器(BTLA)、TIM1 和 CD226 的表达水平与 BRAFV600E 突变状态一起,显著决定了黑色素瘤患者的总生存期。与正常皮肤黑素细胞相比,这些分子(以及疱疹病毒进入介质(HVEM)和 CD160)在人类黑色素瘤组织中的表达水平更高,并且在 T 细胞激活中具有独特的作用,HVEM/BTLA/CD160 轴的两个分子。在黑色素瘤中,新的免疫调节分子表达与 BRAFV600E 遗传病变之间的联系正在被揭示。MAPK 途径的小分子抑制剂调节这种多方面分子的表面表达,使 BTLA 成为免疫肿瘤学的一个有前途的靶点,与小分子抑制剂联合靶向,可能减轻 T 调节细胞的激活并改善患者预后。