Identification of tumor-intrinsic drivers of immune exclusion in acral melanoma

Topical transdermal administration of lenalidomide nanosuspensions-based hydrogels against melanoma: In vitro and in vivo studies

Percutaneous neoadjuvant therapy has proven effective in diminishing tumor size and the surgical intervention area, which couldeffectively mitigate the risk of tumor recurrence and enhance immunotherapy efficacy. Lenalidomide, an approved medication orally used to treat myeloma, was loaded into nanosuspensions-based hydrogels (Len-NBHs) for transdermal administration as a percutaneous neoadjuvant therapy. This study was designed to investigate the inhibitory effect and mechanism of Len-NBHs on melanoma. Network pharmacology and transcriptomic analyses identified key targets and signaling pathways. The effects of lenalidomide on melanoma were further verified through Western blotting, immunohistochemistry, immunofluorescence, and quantitative real-time polymerase chain reaction，using both in vitro cell experiments and in vivo melanoma mouse models. Lenalidomide could induce melanoma cells apoptosis, disrupt cell cycle progression, impede cell migration and invasion, and modify tumor microenvironment (TME). Mechanistically, lenalidomide reversed the abnormal activation of the PI3K-AKT signaling pathway and the overexpression of CD93, while also recruiting CD8+ T cells, CD4+ T cells, and dendritic cells to infiltrate the tumor site. Transdermal administration of Len-NBHs represents a promising adjuvant therapy for the treatment of malignant melanoma. Preoperative administration of Len-NBHs can inhibit the outward spread of melanoma, reduce tumor size, thereby decreasing the surgical excision area and improving patient survival rates and prognosis.

Rewiring lipid metabolism to enhance immunotherapy efficacy in melanoma: a frontier in cancer treatment

Immunotherapy has transformed the landscape of melanoma treatment, offering significant extensions in survival for many patients. Despite these advancements, nearly 50% of melanoma cases remain resistant to such therapies, highlighting the need for novel approaches. Emerging research has identified lipid metabolism reprogramming as a key factor in promoting melanoma progression and resistance to immunotherapy. This reprogramming not only supports tumor growth and metastasis but also creates an immunosuppressive environment that impairs the effectiveness of treatments such as immune checkpoint inhibitors (ICIs). This review delves into the intricate relationship between lipid metabolism and immune system interactions in melanoma. We will explore how alterations in lipid metabolic pathways contribute to immune evasion and therapy resistance, emphasizing recent discoveries in this area. Additionally, we also highlights novel therapeutic strategies targeting lipid metabolism to enhance immune checkpoint inhibitor (ICI) efficacy.

Multi-omics analysis unveils a four-gene prognostic signature in esophageal squamous carcinoma and the therapeutic potential of PKP1

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignancies, characterized by high heterogeneity and poor outcomes. Effective classification for patient stratification and identifying reliable markers for prognosis prediction and treatment choice are crucial.

METHODS

Integration of single-cell RNA-sequencing (RNA-seq) and bulk RNA-seq analyses were used to characterize ESCC. Non-negative matrix factorization (NMF) clustering was performed to stratify the ESCC patients into different subtypes and the clinical and pathological features of the ESCC subtypes were compared. Cox regression analysis and LASSO regression analysis were used to select key genes and construct a risk model for ESCC. The associations of the key genes with anti-cancer drug sensitivities in ESCC cell lines were investigated. RT-qRCR experiments, proteomics analysis, and multiplex immunohistochemistry (mIHC) experiments were used to validate the results. Furthermore, one identified gene was selected to investigate its correlation with EGFR expression and the gene effect scores of various potential gene targets across pan-cancer.

RESULTS

The study identified the dysregulated distributions of epithelial cells and fibroblasts as characteristic of ESCC. ESCC patients could be classified into four distinct subtypes with unique cell type features and prognoses. With the gene makers of the cell type features, a four-gene prognostic signature for ESCC was constructed. The CCND1-PKP1-JUP-ANKRD12 model could effectively discriminate the survival status of ESCC patients, independent of various pathological and clinical features. The risk score for the samples was correlated with the expression levels of immunoregulatory genes. The prognostic effects of CCND1, PKP1, and JUP were confirmed at the protein level. The phosphorylation levels of PKP1, JUP, and ANKRD12 were found to be dysregulated in ESCC tumors. Their expression dysregulation and heterogeneity were demonstrated in ESCC cell lines. All four genes were significantly correlated with at least one of the anti-cancer drug sensitivities in ESCC cell lines. PKP1 expression was significantly correlated with EGFR expression and gene effect scores in multiple cancers.

CONCLUSIONS

We conclude that the CCND1-PKP1-JUP-ANKRD12 signature may serve as a novel indicator for ESCC prognosis and diagnosis. PKP1 expression might provide new clues for gene therapy efficacy in multiple cancers.

Combined programmed cell death protein 1 and cytotoxic T-lymphocyte associated protein 4 blockade in an international cohort of patients with acral lentiginous melanoma

BACKGROUND

Combination immune checkpoint blockade targeting programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte associated protein 4 (CTLA-4) leads to high response rates and improved survival in patients with advanced cutaneous melanoma (CM). Less is known about the efficacy of this combination in acral lentiginous melanoma (ALM).

OBJECTIVES

To determine the efficacy of combination immune checkpoint blockade targeting PD-1 and CTLA-4 in a diverse, real-world population of patients with ALM.

METHODS

This multi-institutional retrospective study analysed patients with histologically confirmed ALM treated with a combination of PD-1 and CTLA-4 inhibitors between 2010 and 2022. The primary objective of the study was the objective response rate (ORR) as per the RECIST criteria. The secondary objectives were progression-free survival (PFS) and overall survival (OS).

RESULTS

In total, 109 patients with advanced ALM treated with combined PD-1 and CTLA-4 blockade in any line of treatment were included. The majority of patients had stage IV disease (n = 81; 74.3%). The ORR for the entire cohort was 18.3% [95% confidence interval (CI) 11.6-26.9], with 9 (8.3%) complete and 11 (10.1%) partial responses. A further 22 patients (20.2%) had stable disease, and the disease control rate was 38.5%. Median PFS was 4.2 months (95% CI 3.25-5.62), while median OS was 17 months (95% CI 12.4-23.1). Ninety-five patients (87.2%) had a treatment-related adverse event, with 40.4% (n = 44/109) experiencing at least one grade 3 or 4 toxicity. Elevated lactate dehydrogenase (P = 0.04), ≥ 2 lines of prior treatment (P = 0.03) and Asian ethnicity (P = 0.04) were associated with worse OS, while Hispanic/Latino ethnicity was associated with better OS (P = 0.02).

CONCLUSIONS

Combination PD-1 and CTLA-4 blockade is less effective for ALM than for CM, despite similar toxicity. In particular, Asian patients appear to derive less benefit from this regimen. Novel treatment approaches are needed for this rare melanoma subtype.

The roles of PD-L1 in the various stages of tumor metastasis

The interaction between tumor programmed death ligand 1 (PD-L1) and T-cell programmed cell death 1 (PD-1) has long been acknowledged as a mechanism for evading immune surveillance. Recent studies, however, have unveiled a more nuanced role of tumor-intrinsic PD-L1 in reprograming tumoral phenotypes. Preclinical models emphasize the synchronized effects of both intracellular and extracellular PD-L1 in promoting metastasis, with intricate interactions with the immune system. This review aims to summarize recent findings to elucidate the spatiotemporal heterogeneity of PD-L1 expression and the pro-metastatic roles of PD-L1 in the entire process of tumor metastasis. For example, PD-L1 regulates the epithelial-to-mesenchymal transition (EMT) process, facilitates the survival of circulating tumor cells, and induces the formation of immunosuppressive environments at pre-metastatic niches and metastatic sites. And the complexed and dynamic regulation process of PD-L1 for tumor metastasis is related to the spatiotemporal heterogeneity of PD-L1 expression and functions from tumor primary sites to various metastatic sites. This review extends the current understandings for the roles of PD-L1 in mediating tumor metastasis and provides new insights into therapeutic decisions in clinical practice.

Single-cell RNA sequencing unveils tumor heterogeneity and immune microenvironment between subungual and plantar melanoma

Acral melanoma (AM) is a subtype of melanoma with high prevalence in East Asians. AM is characterized by greater aggressiveness and lower survival rates. However, there are still fewer studies on immune mechanisms of AM especially subungual melanoma (SM) versus non-subungual melanoma (NSM). In order to explore tumor heterogeneity and immune microenvironment in different subtypes of AM, we applied single-cell RNA sequencing to 24,789 single cells isolated from the SM and plantar melanoma (PM) patients. Aspects of tumor heterogeneity, melanocytes from PM and SM had significant differences in gene expression, CNV and pathways in which tumor-associated such as NF-kb and Wnt were involved. Regarding the immune microenvironment, PM contained more fibroblasts and T/NK cells. The EPHA3-EFNA1 axis was expressed only in cancer-associated fibroblast (CAF) and melanocytes of PM, and the TIGIT-NECTIN2 axis was expressed in both AM subtypes of T/NK cells and melanocytes. Altogether, our study helps to elucidate the tumor heterogeneity in AM subpopulations and provides potential therapeutic targets for clinical research.

Acral melanoma: new insights into the immune and genomic landscape

Acral melanoma is a rare subtype of melanoma that arises on the non-hair bearing skin of the nail bed, palms of the hand and soles of the feet. It is unique among melanomas in not being linked to ultraviolet radiation (UVR) exposure from the sun, and, as such, its incidence is similar across populations who are of Asian, Hispanic, African and European origin. Although research into acral melanoma has lagged behind that of sun-exposed cutaneous melanoma, recent studies have begun to address the unique genetics and immune features of acral melanoma. In this review we will discuss the latest progress in understanding the biology of acral melanoma across different ethnic populations and will outline how these new discoveries can help to guide the therapeutic management of this rare tumor.