TRIM59 通过结合 BCLAF1 调控人皮肤黑色素瘤 SK-MEL-2 细胞的恶 性生物学行为

目的：探究三结构域蛋白59（TRIM59）调控人皮肤黑色素瘤细胞SK-MEL-2增殖、细胞周期、凋亡及迁移侵袭的作用机制，及其与Bcl2相关转录因子1（BCLAF1)之间的关系。方法：qPCR和WB法检测人表皮黑色素细胞HEMn-LP、人皮肤黑色素瘤细胞SK-MEL-2、UACC903、A375及36例邢台市人民医院2019年2月至2021年7月收集的皮肤黑色素瘤组织中TRIM59的mRNA和蛋白表达，使用脂质体将si-con、si-TRIM59转染至SK-MEL-2细胞中，WB法检测干扰TRIM59表达对细胞中周期蛋白D1（CCND1）、细胞周期素依赖性激酶2（CDK2）、肿瘤抑制蛋白基因（TP53）和 BCLAF1 蛋白表达的影响，CCK-8法、流式细胞术、划痕愈合实验、Transwell实验检测对细胞的活性、凋亡、迁移和侵袭的影响，免疫共沉淀（Co-IP）实验检测对细胞中TRIM59蛋白与BCLAF1结合能力的影响。结果：与HEMn-LP细胞相比，SK-MEL-2、UACC903、A375细胞中TRIM59 mRNA和TRIM59、BCLAF1蛋白均呈高表达（均P<0.05），SK-MEL-2细胞中TRIM59表达水平最高。相较于si-con组和Normal组，沉默TRIM59后，SK-MEL-2细胞的活性显著降低，细胞周期阻滞于G2期，CCND1、CDK2的蛋白表达显著降低，TP53蛋白和细胞凋亡率均显著升高，划痕抑制率明显升高，迁移侵袭细胞数明显降低（均P<0.05）。免疫共沉淀实验结果显示，TRIM59与BCLAF1之间存在蛋白结合关系。TRIM59与 BCLAF1 在肿瘤组织中的表达呈显著的正相关（r=0.878，P<0.001）。结论：干扰TRIM59表达能够抑制人皮肤黑色素瘤SK-MEL-2细胞的增殖、迁移和侵袭而促进凋亡，抑制SK-MEL-2细胞的恶性生物学行为，其机制可能与TRIM59结合BCLAF1有关。     

Molecular testing for melanocytic tumors: a practical update

The work-up of melanocytic tumors has undergone significant changes in the last years following the exponential growth of molecular assays. For the practicing pathologist it is often difficult to sort through the myriad of different tests available currently for clinical use. The molecular tests used in melanocytic pathology can be broadly divided into 4 categories: (i) Tests useful in the differential diagnosis of nevus versus melanoma (primarily used as an aid in the diagnosis of histologically ambiguous melanocytic tumors), (ii) Tests that predict prognosis in melanoma, (iii) Tests useful in the classification of melanocytic tumors and (iv) Tests that predict response to systemic therapy in melanoma. This review will present an updated overview of major ancillary tests used in clinical practice.     

Exploring a 7-gene prognostic model based on ferroptosis for efficiently guiding immunotherapy in melanoma patients

PurposeAlthough skin cutaneous melanoma (SKCM) is a relatively immunotherapy-sensitive tumor type, there is still a certain fraction that benefits less from treatment. Ferroptosis has been demonstrated to modulate tumor progression in many cancer types. This study focused on ferroptosis-related genes to construct a prognostic model for SKCM patients.Materials and methodsGene expression profiles of SKCM samples were obtained from public databases. Unsupervised consensus clustering was used to determine molecular subtypes related to ferroptosis. Least absolute shrinkage and selection operator (LASSO) and stepwise Akaike information criterion (stepAIC) were applied to construct a prognostic model based on differentially expressed genes between two molecular subtypes.ResultsC1 and C2 subtypes were identified with differential prognosis and immune infiltration. A 7-gene prognostic model was constructed to classify samples into high-FPRS and low-FPRS groups. Low-FPRS group with favorable prognosis had higher immune infiltration and more enriched immune-related pathways than the high-FPRS group. The two groups showed distinct sensitivity to immunotherapy, with the low-FPRS group predicted to have more positive response to immunotherapy than the high-FPRS group. A nomogram based on the FPRS score and clinical features was built for more convenient use.ConclusionsThe critical role of ferroptosis involved in SKCM development was further validated in this study. The prognostic model was efficient and stable to be applied in clinical conditions to support clinicians in determining personalized therapy for SKCM patients especially those with metastasis.     

Iterative treatment with surgery and radiofrequency ablation of uveal melanoma liver metastasis: Retrospective analysis of a series of very long-term survivors

BackgroundAfter treatment of primary ocular uveal melanoma (UM), up to 50% of patients will develop metastases, mostly in the liver. Systemic treatments do not provide any overall survival benefit for these patients and surgery remains the most effective therapy for selected patients. Radiofrequency ablation (RFA) alone or in combination with surgery is frequently used to spare hepatic parenchyma. When patients relapse after treatment of their first metastases, and when the liver recurrence is limited, new local liver treatment is questionable.MethodsA total of 14 patients with liver metastases from uveal melanoma (LMUM) were retrospectively evaluated. All patients had a complete first liver resection and a second treatment with RFA. Overall survival, recurrence-free interval after the first and the second treatment was evaluated.ResultsTreatment of hepatic recurrence was percutaneous RFA for ten patients and per-operative RFA for four patients associated with new metastasectomy. The median time to onset of LMUMs after ocular UM treatment was 50 months, and the median time to recurrence of hepatic metastasis after the first liver treatment was 20 months. The overall survival was 70% at five years and 35% at ten years. The recurrence-free interval was 50% and 56% at two years after the first and the second treatment, respectively.ConclusionProlonged survival can be achieved by exclusive and iterative local treatment combining surgery and RFA in a small proportion of patients with a first recurrence of isolated LMUM.     

Updates in adjuvant systemic therapy for melanoma

There has been a rapid increase in adjuvant therapies approved for treatment following surgical resection of stages III/IV melanoma. We review current indications for adjuvant therapy, which currently includes a heterogenous group of stages III and IV patients with melanoma. We describe several pivotal clinical trials of systemic immune therapies, targeted immune therapies, and adjuvant vaccine strategies. Finally, we discuss the evidence for selecting the most appropriate treatment regimen(s) for the individual patient.     

Melanoma of unknown primary

Formally described in the 1960s, melanoma of unknown primary (MUP) is characterized by the finding of metastatic melanoma within the lymph nodes, subcutaneous tissues, and other distant sites without an evident primary lesion. The most likely hypothesis of its etiology is an immune-mediated regression of the primary after metastasis has occurred. In addition, patients with MUP appear to have equivalent or better outcomes compared with patients with known primaries of a similar stage.     

4′‐Bromo‐resveratrol,a dual Sirtuin‐1 and Sirtuin‐3 inhibitor,inhibits melanoma cell growth through mitochondrial metabolic reprogramming

Sirtuin‐1 and ‐3 (SIRT1 and SIRT3) are important nicotinamide adenine dinucleotide (NAD⁺)‐dependent deacetylases known to regulate a variety of cellular functions. Studies have shown that SIRT1 and SIRT3 were overexpressed in human melanoma cells and tissues and their inhibition resulted in a significant antiproliferative response in human melanoma cells and antitumor response in a mouse xenograft model of melanoma. In this study, we determined the antiproliferative efficacy of a newly identified dual small molecule inhibitor of SIRT1 and SIRT3, 4′‐bromo‐resveratrol (4′‐BR), in human melanoma cell lines (G361, SK‐MEL‐28, and SK‐MEL‐2). Our data demonstrate that 4′‐BR treatment of melanoma cells resulted in (a) decrease in proliferation and clonogenic survival; (b) induction of apoptosis accompanied by a decrease in procaspase‐3, procaspase‐8, and increase in the cleavage of caspase‐3 and poly (ADP‐ribose) polymerase (PARP); (c) marked downregulation of proliferating cell nuclear antigen (PCNA); and (d) inhibition of melanoma cell migration. Further, 4′‐BR caused a G0/G1 phase arrest of melanoma cells that was accompanied by an increase in WAF‐1/P21 and decrease in Cyclin D1/Cyclin‐dependent kinase 6 protein levels. Furthermore, we found that 4′‐BR causes a decrease in lactate production, glucose uptake, and NAD⁺/NADH ratio. These responses were accompanied by downregulation in lactate dehydrogenase A and glucose transporter 1 in melanoma cells. Collectively, our data suggest that dual inhibition of SIRT1 and SIRT3 using 4′‐BR imparted antiproliferative effects in melanoma cells through a metabolic reprogramming and affecting the cell cycle and apoptosis signaling. Therefore, concomitant pharmacological inhibition of SIRT1 and SIRT3 needs further investigation for melanoma management.