葡萄膜黑色素瘤是最常见的非皮肤黑色素瘤，是一种眼内恶性肿瘤，每年影响全球近 7,000 人。其中，大约 50% 将进展为转移性疾病，目前尚无有效的治疗方法。尽管葡萄膜黑色素瘤肿瘤的分子谱分析和转移分层取得了进展，但对其转移的潜在生物学知之甚少。我们的小组在葡萄膜黑色素瘤患者中鉴定出了一种播散性肿瘤细胞群，其特征是免疫蛋白和黑色素瘤蛋白的共表达，即循环杂交细胞（杂交细胞）。与缺乏免疫蛋白表达的循环肿瘤细胞相比，杂交细胞在外周血中的检测率更高，可用作预测转移进展的非侵入性生物标志物。为了确定杂交细胞传播增强的机制，我们鉴定了杂交细胞使用单细胞 RNA 测序（n = 8）在原发性葡萄膜黑色素瘤肿瘤中进行研究，并评估其基因表达并预测与原发性肿瘤内其他黑色素瘤和免疫细胞相关的配体-受体相互作用。然后，我们使用循环免疫荧光验证了患者匹配的肿瘤和外周血杂交体 (n = 4) 中上调的杂交途径的表达，并量化了它们相对于其他非杂交肿瘤和播散性肿瘤细胞的蛋白质表达。杂交细胞是那些参与增强细胞运动和细胞骨架重排、免疫逃避和改变细胞代谢的细胞。在患者匹配的肿瘤和外周血中，我们通过检查每个途径类别的一致蛋白表达来验证基因表达：TMSB10（细胞运动）、CD74（免疫逃避）和GPX1（代谢）。与循环肿瘤细胞相比，TMSB10 和 GPX1 在数量显着更高的播散性杂交细胞上表达，并且 CD74 和 GPX1 在比肿瘤驻留杂交细胞更多的播散性杂交细胞上表达。最后，我们发现杂交细胞表达与促进转移有关的配体-受体信号通路，包括 GAS6-AXL、CXCL12-CXCR4、LGALS9-P4HB 和 IGF1-IGFR1。这些发现强调了 TMSB10、GPX1 和 CD74 对于成功的杂交细胞传播的重要性并在循环中生存。我们的结果有助于了解葡萄膜黑色素瘤的进展以及肿瘤微环境中肿瘤细胞与免疫细胞之间可能促进转移的相互作用。© 2024。作者。

Uveal melanoma is the most common non-cutaneous melanoma and is an intraocular malignancy affecting nearly 7,000 individuals per year worldwide. Of these, approximately 50% will progress to metastatic disease for which there are currently no effective curative therapies. Despite advances in molecular profiling and metastatic stratification of uveal melanoma tumors, little is known regarding their underlying biology of metastasis. Our group has identified a disseminated neoplastic cell population characterized by co-expression of immune and melanoma proteins, circulating hybrid cells (hybrids), in patients with uveal melanoma. Compared to circulating tumor cells, which lack expression of immune proteins, hybrids are detected at an increased prevalence in peripheral blood and can be used as a non-invasive biomarker to predict metastatic progression.To ascertain mechanisms underlying enhanced hybrid cell dissemination we identified hybrid cells within primary uveal melanoma tumors using single cell RNA sequencing (n = 8) and evaluated their gene expression and predicted ligand-receptor interactions in relation to other melanoma and immune cells within the primary tumor. We then verified expression of upregulated hybrid pathways within patient-matched tumor and peripheral blood hybrids (n = 4) using cyclic immunofluorescence and quantified their protein expression relative to other non-hybrid tumor and disseminated tumor cells.Among the top upregulated genes and pathways in hybrid cells were those involved in enhanced cell motility and cytoskeletal rearrangement, immune evasion, and altered cellular metabolism. In patient-matched tumor and peripheral blood, we verified gene expression by examining concordant protein expression for each pathway category: TMSB10 (cell motility), CD74 (immune evasion) and GPX1 (metabolism). Both TMSB10 and GPX1 were expressed on significantly higher numbers of disseminated hybrid cells compared to circulating tumor cells, and CD74 and GPX1 were expressed on more disseminated hybrids than tumor-resident hybrids. Lastly, we identified that hybrid cells express ligand-receptor signaling pathways implicated in promoting metastasis including GAS6-AXL, CXCL12-CXCR4, LGALS9-P4HB and IGF1-IGFR1.These findings highlight the importance of TMSB10, GPX1 and CD74 for successful hybrid cell dissemination and survival in circulation. Our results contribute to the understanding of uveal melanoma tumor progression and interactions between tumor cells and immune cells in the tumor microenvironment that may promote metastasis.© 2024. The Author(s).