PDF(Pubmed)
Abstract：
UNASSIGNED: Advanced cutaneous melanoma is a skin cancer characterized by a poor prognosis and high metastatic potential. During metastatic spread, melanoma cells often undergo dedifferentiation toward an invasive phenotype, resulting in reduced expression of microphthalmia-associated transcription factor (MITF)-dependent melanoma antigens and facilitating immune escape. Tumor Necrosis Factor (TNF) is known to be a key factor in melanoma dedifferentiation. Interestingly, accumulating evidence suggests that TNF may play a role in melanoma progression and resistance to immunotherapies. Additionally, TNF has been identified as a potent regulator of sphingolipid metabolism, which could contribute to melanoma aggressiveness and the process of melanoma dedifferentiation.
UNASSIGNED: We conducted RNA sequencing and mass spectrometry analyses to investigate TNF-induced dedifferentiation in two melanoma cell lines. In vitro experiments were performed to manipulate sphingolipid metabolism using genetic or pharmacologic alterations in combination with TNF treatment, aiming to elucidate the potential involvement of this metabolism in TNF-induced dedifferentiation. Lastly, to evaluate the clinical significance of our findings, we performed unsupervised analysis of plasma sphingolipid levels in 48 patients receiving treatment with immune checkpoint inhibitors, either alone or in combination with anti-TNF therapy.
UNASSIGNED: Herein, we demonstrate that TNF-induced melanoma cell dedifferentiation is associated with a global modulation of sphingolipid metabolism. Specifically, TNF decreases the expression and activity of acid ceramidase (AC), encoded by the ASAH1 gene, while increasing the expression of glucosylceramide synthase (GCS), encoded by the UGCG gene. Remarkably, knockdown of AC alone via RNA interference is enough to induce melanoma cell dedifferentiation. Furthermore, treatment with Eliglustat, a GCS inhibitor, inhibits TNF-induced melanoma cell dedifferentiation. Lastly, analysis of plasma samples from patients treated with immune checkpoint inhibitors, with or without anti-TNF therapy, revealed significant predictive sphingolipids. Notably, the top 8 predictive sphingolipids, including glycosphingolipids, were associated with a poor response to immunotherapy.
UNASSIGNED: Our study highlights that ceramide metabolism alterations are causally involved in TNF-induced melanoma cell dedifferentiation and suggests that the evolution of specific ceramide metabolites in plasma may be considered as predictive biomarkers of resistance to immunotherapy.
UNASSIGNED: We conducted RNA sequencing and mass spectrometry analyses to investigate TNF-induced dedifferentiation in two melanoma cell lines. In vitro experiments were performed to manipulate sphingolipid metabolism using genetic or pharmacologic alterations in combination with TNF treatment, aiming to elucidate the potential involvement of this metabolism in TNF-induced dedifferentiation. Lastly, to evaluate the clinical significance of our findings, we performed unsupervised analysis of plasma sphingolipid levels in 48 patients receiving treatment with immune checkpoint inhibitors, either alone or in combination with anti-TNF therapy.
UNASSIGNED: Herein, we demonstrate that TNF-induced melanoma cell dedifferentiation is associated with a global modulation of sphingolipid metabolism. Specifically, TNF decreases the expression and activity of acid ceramidase (AC), encoded by the ASAH1 gene, while increasing the expression of glucosylceramide synthase (GCS), encoded by the UGCG gene. Remarkably, knockdown of AC alone via RNA interference is enough to induce melanoma cell dedifferentiation. Furthermore, treatment with Eliglustat, a GCS inhibitor, inhibits TNF-induced melanoma cell dedifferentiation. Lastly, analysis of plasma samples from patients treated with immune checkpoint inhibitors, with or without anti-TNF therapy, revealed significant predictive sphingolipids. Notably, the top 8 predictive sphingolipids, including glycosphingolipids, were associated with a poor response to immunotherapy.
UNASSIGNED: Our study highlights that ceramide metabolism alterations are causally involved in TNF-induced melanoma cell dedifferentiation and suggests that the evolution of specific ceramide metabolites in plasma may be considered as predictive biomarkers of resistance to immunotherapy.
摘要：
晚期皮肤黑素瘤是一种以预后差和高转移潜能为特征的皮肤癌。在转移扩散期间，黑色素瘤细胞通常会向侵袭性表型去分化，导致小眼相关转录因子（MITF）依赖性黑色素瘤抗原的表达降低，并促进免疫逃逸。已知肿瘤坏死因子(TNF)是黑素瘤去分化的关键因素。有趣的是,越来越多的证据表明，TNF可能在黑色素瘤的进展和对免疫疗法的抵抗中起作用。此外,TNF已被确定为鞘脂代谢的有效调节剂，这可能有助于黑素瘤侵袭性和黑素瘤去分化的过程。
我们进行了RNA测序和质谱分析，以研究两种黑素瘤细胞系中TNF诱导的去分化。使用遗传或药理学改变结合TNF治疗进行体外实验以操纵鞘脂代谢。旨在阐明这种代谢在TNF诱导的去分化中的潜在参与。最后,为了评估我们发现的临床意义，我们对48例接受免疫检查点抑制剂治疗的患者的血浆鞘脂水平进行了无监督分析，单独或与抗TNF治疗组合。
■这里，我们证明TNF诱导的黑色素瘤细胞去分化与鞘脂代谢的整体调节有关。具体来说,TNF降低酸性神经酰胺酶（AC）的表达和活性，由ASAH1基因编码，同时增加葡萄糖神经酰胺合酶（GCS）的表达，由UGCG基因编码。值得注意的是,通过RNA干扰单独敲除AC足以诱导黑色素瘤细胞去分化。此外，用Eliglustat治疗，GCS抑制剂，抑制TNF诱导的黑色素瘤细胞去分化。最后,对接受免疫检查点抑制剂治疗的患者的血浆样本进行分析，有或没有抗TNF治疗，揭示了显著的预测鞘脂。值得注意的是,前8个预测鞘脂，包括鞘糖脂，与免疫疗法反应不良有关。
■我们的研究强调神经酰胺代谢改变与TNF诱导的黑素瘤细胞去分化有因果关系，并提示血浆中特定神经酰胺代谢产物的进化可被视为免疫疗法耐药的预测生物标志物。
我们进行了RNA测序和质谱分析，以研究两种黑素瘤细胞系中TNF诱导的去分化。使用遗传或药理学改变结合TNF治疗进行体外实验以操纵鞘脂代谢。旨在阐明这种代谢在TNF诱导的去分化中的潜在参与。最后,为了评估我们发现的临床意义，我们对48例接受免疫检查点抑制剂治疗的患者的血浆鞘脂水平进行了无监督分析，单独或与抗TNF治疗组合。
■这里，我们证明TNF诱导的黑色素瘤细胞去分化与鞘脂代谢的整体调节有关。具体来说,TNF降低酸性神经酰胺酶（AC）的表达和活性，由ASAH1基因编码，同时增加葡萄糖神经酰胺合酶（GCS）的表达，由UGCG基因编码。值得注意的是,通过RNA干扰单独敲除AC足以诱导黑色素瘤细胞去分化。此外，用Eliglustat治疗，GCS抑制剂，抑制TNF诱导的黑色素瘤细胞去分化。最后,对接受免疫检查点抑制剂治疗的患者的血浆样本进行分析，有或没有抗TNF治疗，揭示了显著的预测鞘脂。值得注意的是,前8个预测鞘脂，包括鞘糖脂，与免疫疗法反应不良有关。
■我们的研究强调神经酰胺代谢改变与TNF诱导的黑素瘤细胞去分化有因果关系，并提示血浆中特定神经酰胺代谢产物的进化可被视为免疫疗法耐药的预测生物标志物。
