Department of Experimental and Clinical Biomedical Sciences Mario Serio, University of FlorenceFlorenceItaly.
Laboratory of Nanotecnology, IRCCS Istituto Tumori Giovanni Paolo II,BariItaly.
Oncol Res. 2022 Jan 31;28(9):873-884. doi: 10.3727/096504021X16273798026651. Epub 2021 Jul 27.
Malignant melanoma is a highly aggressive skin cancer characterized by an elevated grade of tumor cell plasticity. Such plasticity allows adaptation of melanoma cells to different hostile conditions and guarantees tumor survival and disease progression, including aggressive features such as drug resistance. Indeed, almost 50% of melanoma rapidly develop resistance to the BRAF inhibitor vemurafenib, with fast tumor dissemination, a devastating consequence for patients outcomes. Vasculogenic mimicry (VM), the ability of cancer cells to organize themselves in perfused vascular-like channels, might sustain tumor spread by providing vemurafenib-resistant cancer cells with supplementary ways to enter into circulation and disseminate. Thus, this research aims to determine if vemurafenib resistance goes with the acquisition of VM ability by aggressive melanoma cells, and identify a driving molecule for both vemurafenib resistance and VM. We used two independent experimental models of drug-resistant melanoma cells, the first one represented by a chronic adaptation of melanoma cells to extracellular acidosis, known to drive a particularly aggressive and vemurafenib-resistant phenotype, the second one generated with chronic vemurafenib exposure. By performing in vitro tube formation assay and evaluating the expression levels of the VM markers EphA2 and VE-cadherin by Western blotting and flow cytometer analyses, we demonstrated that vemurafenib-resistant cells obtained by both models are characterized by an increased ability to perform VM. Moreover, by exploiting the CRISPR-Cas9 technique and using the urokinase plasminogen activator receptor (uPAR) inhibitor M25, we identified uPAR as a driver of VM expressed by vemurafenib-resistant melanoma cells. Thus, uPAR targeting may be successfully leveraged as a new complementary therapy to inhibit VM in drug-resistant melanoma patients, to counteract the rapid progression and dissemination of the disease.
恶性黑色素瘤是一种高度侵袭性的皮肤癌，其特征是肿瘤细胞可塑性升高。这种可塑性使黑色素瘤细胞能够适应不同的恶劣环境，并保证肿瘤的存活和疾病的进展，包括耐药等侵袭性特征。事实上，近 50%的黑色素瘤患者对 BRAF 抑制剂维莫非尼迅速产生耐药性，导致肿瘤快速扩散，这对患者的预后造成严重影响。血管生成拟态（VM），即癌细胞能够自我组织成灌注的类似血管的通道的能力，可能通过为维莫非尼耐药的癌细胞提供补充进入循环和扩散的途径来维持肿瘤的扩散。因此，本研究旨在确定维莫非尼耐药是否伴随着侵袭性黑色素瘤细胞获得 VM 能力，并鉴定出与维莫非尼耐药和 VM 相关的驱动分子。我们使用了两种独立的耐药黑色素瘤细胞实验模型，第一种模型是通过黑色素瘤细胞对细胞外酸中毒的慢性适应来代表，已知这种适应会导致特别侵袭性和维莫非尼耐药的表型；第二种模型是通过慢性维莫非尼暴露产生的。通过进行体外管形成实验，并通过 Western blot 和流式细胞仪分析评估 VM 标志物 EphA2 和 VE-cadherin 的表达水平，我们证明了两种模型获得的维莫非尼耐药细胞具有增强的 VM 能力。此外，通过利用 CRISPR-Cas9 技术和使用尿激酶型纤溶酶原激活物受体 (uPAR) 抑制剂 M25，我们确定 uPAR 是维莫非尼耐药黑色素瘤细胞表达的 VM 的驱动分子。因此，靶向 uPAR 可能成功地用作耐药黑色素瘤患者抑制 VM 的新辅助治疗方法，以抵抗疾病的快速进展和扩散。
