Immunotherapy for Melanoma: The Significance of Immune Checkpoint Inhibitors for the Treatment of Advanced Melanoma

Changes in mucosa‑associated lymphoid tissue 1 predicts therapeutic response and survival in patients with advanced melanoma receiving programmed cell death‑1 inhibitor monotherapy

Advanced melanoma is an aggressive and dangerous form of skin cancer, and programmed cell death-1 (PD-1) inhibitors are recommended treatment options for patients with advanced melanoma. Mucosa-associated lymphoid tissue 1 (MALT1) impairs CD8+ T-cell activation to induce immune escape, leading to a reduction in the antitumor effect of PD-1 inhibitors. The present study aimed to assess the prognostic implication of MALT1 in patients with advanced melanoma receiving PD-1 inhibitor monotherapy. Blood MALT1 levels were assessed using reverse transcription-quantitative PCR in 20 healthy controls (HCs) after enrollment and in 49 patients with advanced melanoma before (T0), as well as 2 months (T1) and 4 months after (T2) PD-1 inhibitor monotherapy. The maximum level of MALT1 in HCs (3.100) was used as the cut-off in patients with advanced melanoma. MALT1 levels at T0 were significantly increased in patients with advanced melanoma compared with in HCs (P<0.001). In patients with advanced melanoma, MALT1 was significantly decreased from T0 to T2 (P<0.001). Objective response rate (ORR) and disease control rate (DCR) were 28.6 and 59.2%, respectively. MALT1 levels at T1 were significantly negatively associated with overall therapeutic response (P=0.001), ORR (P=0.009) and DCR (P=0.004). MALT1 levels at T2 were significantly inversely associated with overall therapeutic response (P=0.021) and ORR (P=0.036). Moreover, MALT1 levels >3.100 at T0 (P=0.027) and T1 (P=0.045) were significantly associated with shorter progression-free survival (PFS), and MALT1 levels >3.100 at T1 were significantly associated with a poor overall survival (OS; P=0.022). Multivariate Cox regression analysis demonstrated that MALT1 levels at T0 (>3.100 vs. ≤3.100) were significantly associated with a poor PFS [hazard ratio (HR)=2.248; P=0.037], and MALT1 levels at T1 (>3.100 vs. ≤3.100) were significantly associated with a poor OS (HR=4.332; P=0.007). In conclusion, MALT1 levels are reduced following PD-1 treatment, and a high MALT1 level is associated with a poor therapeutic response and shorter survival in patients with advanced melanoma receiving PD-1 inhibitor monotherapy.

Adverse events associated with postoperative outcomes of adjuvant anti-PD-1 antibody therapy in both acral and non-acral cutaneous melanomas: A multicenter, observational, post hoc analysis study

Since anti-PD-1 Abs can cause irreversible immune-related adverse events (irAEs), the associations between their efficacies and the incidence of irAEs are important to evaluate the use of anti-PD-1Abs for the treatment of melanoma, especially in the adjuvant setting. The purpose of this post hoc analysis study was to retrospectively analyze the associations between recurrence-free survival (RFS) at 12 months and the onset of any irAEs in 31 non-acral cutaneous and 30 acral melanoma cases treated with anti-PD-1 Abs therapy at the adjuvant setting in Asians. There were 20 cases with greater than grade 1 AEs in both the acral and non-acral cutaneous groups. Of the acral melanoma, 10 cases were nails or toes, and 20 cases were soles and heels. The log-rank test showed that RFS was better in cases with AEs than in cases without AEs. The present study suggested that the different profiles of irAEs between non-acral cutaneous and acral melanoma might correlate with the different response to anti-PD1 Abs of melanoma in the adjuvant setting.

The Role of Transglutaminase 2 in Cancer: An Update

Transglutaminase type 2 (TG2) is the most ubiquitously expressed and well characterized member of the transglutaminase family. It is a ubiquitous multifunctional enzyme implicated in the regulation of several cellular pathways that support the survival, death, and general homeostasis of eukaryotic cells. Due to its multiple localizations both inside and outside the cell, TG2 participates in the regulation of many crucial intracellular signaling cascades in a tissue- and cell-specific manner, making this enzyme an important player in disease development and progression. Moreover, TG2 is capable of modulating the tumor microenvironment, a process of dynamic tissue remodeling and biomechanical events, resulting in changes which influence tumor initiation, growth, and metastasis. Even if generally related to the Ca2+-dependent post-translational modification of proteins, a number of different biological functions have been ascribed to TG2, like those of a peptide isomerase, protein kinase, guanine nucleotide binder, and cytosolic-nuclear translocator. With respect to cancer, TG2's role is controversial and highly debated; it has been described both as an anti- and pro-apoptotic factor and is linked to all the processes of tumorigenesis. However, numerous pieces of evidence support a tissue-specific role of TG2 so that it can assume both oncogenic and tumor-suppressive roles.

Lnc-PKNOX1-1 inhibits tumor progression in cutaneous malignant melanoma by regulating NF-κB/IL-8 axis

Cutaneous malignant melanoma is one of the most lethal cutaneous malignancies. Accumulating evidence has demonstrated the potential influence of long non-coding RNAs (lncRNAs) in biological behaviors of melanoma. Herein, we reported a novel lncRNA, lnc-PKNOX1-1 and systematically studied its functions and possible molecular mechanisms in melanoma. Reverse transcription-quantitative PCR assay showed that lnc-PKNOX1-1 was significantly decreased in melanoma cells and tissues. Low lnc-PKNOX1-1 expression was significantly correlated with invasive pathological type and Breslow thickness of melanoma. In vitro and in vivo experiments showed lnc-PKNOX1-1 dramatically inhibited melanoma cell proliferation, migration and invasion. Mechanically, protein microarray analysis suggested that interleukin-8 (IL-8) was negatively regulated by lnc-PKNOX1-1 in melanoma, which was confirmed by western blot and ELISA. Western blot analysis also showed that lnc-PKNOX1-1 could promote p65 phosphorylation at Ser536 in melanoma. Subsequent rescue assays proved IL-8 overexpression could partly reverse the tumor-suppressing function of lnc-PKNOX1-1 overexpression in melanoma cells, indicating that lnc-PKNOX1-1 suppressed the development of melanoma by regulating IL-8. Taken together, our study demonstrated the tumor-suppressing ability of lnc-PKNOX1-1 in melanoma, suggesting its potential as a novel diagnostic biomarker and therapeutic target for melanoma.

Exercise sensitizes PD-1/PD-L1 immunotherapy as a hypoxia modulator in the tumor microenvironment of melanoma

Introduction

Hypoxia is associated with unfavorable prognoses in melanoma patients, and the limited response rates of patients to PD-1/PD-L1 blockade could be attributed to the immunosuppressive tumor microenvironment induced by hypoxia. Exercise offers numerous benefits in the anti-tumor process and has the potential to alleviate hypoxia; however, the precise mechanisms through which it exerts its anti-tumor effects remain unclear, and the presence of synergistic effects with PD-1/PD-L1 immunotherapy is yet to be definitively established.

Methods

We established a B16F10 homograft malignant melanoma model and implemented two distinct exercise treatments (low/moderate-intensity swim) based on the mice's exercise status. The specific function manner of exercise-induced anti-tumor effects was determined through RNA sequencing and analysis of changes in the tumor microenvironment. Furthermore, moderate-intensity swim that exhibited superior tumor suppression effects was combined with Anti-PD-1 treatment to evaluate its in vivo efficacy in mouse models.

Results

Exercise intervention yielded a considerable effect in impeding tumor growth and promoting apoptosis. Immunohistochemistry and RNA sequencing revealed improvements in tumor hypoxia and down-regulation of hypoxia-related pathways. Cellular immunofluorescence and ELISA analyses demonstrated a notable increase of cytotoxic T cell amount and a decrease of regulatory T cells, indicating an improvement of tumor immune microenvironment. In comparison to Anti-PD-1 monotherapy, tumor suppressive efficacy of exercise combination therapy was found to be enhanced with improvements in both the hypoxic tumor microenvironment and T cell infiltration.

Conclusion

Exercise has the potential to function as a hypoxia modulator improving the tumor immune microenvironment, resulting in the promotion of anti-tumor efficacy and the facilitation of biologically safe sensitization of PD-1/PD-L1 immunotherapy.

Postoperative adjuvant therapy for 120 patients with melanoma, including acral and mucosal subtypes: a multicentre, observational study of 2-year follow-up results

We retrospectively analysed 120 cases of melanoma in Japanese patients in the adjuvant setting as an observational study. Nonacral cutaneous-type melanoma (low-CSD and high-CSD types) had significantly better RFS than acral-type melanoma. On multivariate analyses, the acral subtype and agents used in adjuvant therapy were identified as important prognostic factors.

Microbiomes, Their Function, and Cancer: How Metatranscriptomics Can Close the Knowledge Gap

The interaction between the microbial communities in the human body and the onset and progression of cancer has not been investigated until recently. The vast majority of the metagenomics research in this area has concentrated on the composition of microbiomes, attempting to link the overabundance or depletion of certain microorganisms to cancer proliferation, metastatic behaviour, and its resistance to therapies. However, studies elucidating the functional implications of the microbiome activity in cancer patients are still scarce; in particular, there is an overwhelming lack of studies assessing such implications directly, through analysis of the transcriptome of the bacterial community. This review summarises the contributions of metagenomics and metatranscriptomics to the knowledge of the microbial environment associated with several cancers; most importantly, it highlights all the advantages that metatranscriptomics has over metagenomics and suggests how such an approach can be leveraged to advance the knowledge of the cancer bacterial environment.

B7-H3 drives immunosuppression and Co-targeting with CD47 is a new therapeutic strategy in β-catenin activated melanomas

In melanoma, immune cell infiltration into the tumor is associated with better patient outcomes and response to immunotherapy. T-cell non-inflamed tumors (cold tumors) are associated with tumor cell-intrinsic Wnt/β-catenin activation, and are typically resistant to anti-PD-1 alone or in combination with anti-CTLA-4 therapy. Reversal of the 'cold tumor' phenotype and identifying new effective immunotherapies are challenges. We sought to investigate the role of a newer immunotherapy agent, B7-H3, in this setting. RNA sequencing was used to identify co-targeting strategies upon B7-H3 inhibition in a well-defined preclinical melanoma model driven by β-catenin. We found that immune checkpoint molecule B7-H3 confers a suppressive tumor microenvironment by modulating antiviral signals and innate immunity. B7-H3 inhibition led to an inflamed microenvironment, up-regulation of CD47/SIRPa signaling, and together with blockade of the macrophage checkpoint CD47 resulted in additive antitumor responses. We found that the antitumor effects of the B7-H3/CD47 antibody combination were dependent on cytokine signaling pathways (CCR5/CCL5 and IL4).

Efficacy and Safety of PD-1/PD-L1 Inhibitor as Single-Agent Immunotherapy in Endometrial Cancer: A Systematic Review and Meta-Analysis

The programmed cell death protein 1 (PD-1)/programmed cell death ligand 1 (PD-L1) pathway plays a crucial role in the immune escape mechanism and growth of cancer cells in endometrial cancer (EC). Clinical trials investigating PD-1/PD-L1 inhibitor have shown promising results in other cancers, but their efficacy in EC still remains uncertain. Therefore, this meta-analysis aims to provide an updated and robust analysis of the effectiveness and safety of PD-1/PDL1 inhibitor as single-agent immunotherapy in EC, focusing on the objective response rate (ORR), disease control rate (DCR), and adverse events (AEs). This meta-analysis utilized STATA version 17 and RevMan version 5.4 software to pool the results of relevant studies. Five studies conducted between 2017 and 2022, comprising a total of 480 EC patients enrolled for PD-1/PD-L1 inhibitor immunotherapy met the inclusion criteria. The pooled proportion of EC patients who achieved ORR through PD-1/PD-L1 inhibitor treatment was 26.0% (95% CI: 16.0-36.0%; p < 0.05). Subgroup analysis based on mismatch repair (MMR) status showed an ORR of 44.0% (95% CI: 38.0-50.0%; p = 0.32) for the deficient mismatch repair (dMMR) group and 8.0% (95% CI: 0.0-16.0%; p = 0.07) for the proficient mismatch repair (pMMR) group. Pooled proportion analysis by DCR demonstrated an odds ratio (OR) of 41.0% (95% CI: 36.0-46.0%, p = 0.83) for patients undergoing PD-1/PD-L1 inhibitor treatment. Subgroup analysis based on MMR status revealed DCR of 54.0% (95% CI: 47.0-62.0%; p = 0.83) for the dMMR group, and 31.0% (95% CI: 25.0-39.0%; p = 0.14) for the pMMR group. The efficacy of PD-1/PD-L1 inhibitors was significantly higher in the dMMR group compared to the pMMR group, in terms of both ORR (OR = 6.30; 95% CI = 3.60-11.03; p < 0.05) and DCR (OR = 2.57; 95% CI = 1.66-3.99; p < 0.05). In terms of safety issues, the pooled proportion of patients experiencing at least one adverse event was 69.0% (95% CI: 65.0-73.0%; p > 0.05), with grade three or higher AEs occurring in 16.0% of cases (95% CI: 12.0-19.0%; p > 0.05). Based on the subgroup analysis of MMR status, PD-1/PD-L1 inhibitor immunotherapy showed significantly better efficacy among dMMR patients. These findings suggest that patients with dMMR status may be more suitable for this treatment approach. However, further research on PD-1/PD-L1 inhibitor immunotherapy strategies is needed to fully explore their potential and improve treatment outcomes in EC.

Immune checkpoint inhibitors in advanced cutaneous melanoma: a systematic review and meta-analysis of efficacy and review of characteristics

OBJECTIVES

Immune checkpoint inhibitors (ICIs) are one of the most promising approaches toward advanced melanoma. Here, we aimed to perform a meta-analysis of randomized controlled trials (RCTs) to evaluate the efficacy of all studied ICIs.

METHODS

We conducted a comprehensive search to identify the relevant publications (PROSPERO registration ID: CRD42023470649). Then we performed a meta-analysis to evaluate the efficacy of different ICIs for metastatic melanoma. We used Cochrane's tool to assess the quality of studies. The outcome measures were overall survival (OS), progression-free survival (PFS), and recurrence-free survival (RFS).

RESULTS

Twenty reports of RCTs entered our systematic review, 18 of which were included in our data analysis. ICIs showed improved survival compared with control group (hazard ratio (HR) = 0.57; 95% CI: 0.43-0.71; P<0.001). Using a meta-regression, we found a significant relation between patients' mean age and their OS (P<0.001, R 2  = 100.00%). Also, our analysis revealed greater HR for CTLA-4 inhibitors than PD-1/PD-L1 inhibitors (HR = 0.71, 95%CI: 0.63-0.79, P<0.001 vs. HR = 0.63, 95%CI: 0.46-0.79, P<0.001). The effect sizes of different types of PD-1/PD-L1 inhibitors were comparable.

CONCLUSION

Our results suggest that ICI-based immunotherapy is associated with enhanced OS, PFS, and RFS (P < 0.001) and will assist clinicians in choosing the optimal approach toward treating metastatic melanoma.

Cutaneous Adverse Reactions of Immunotherapy in Patients with Advanced Melanoma

Immune checkpoint blockers (ICBs) have been widely used during the last decade for the treatment of various tumors, including advanced and metastatic melanoma. While these agents have improved melanoma patients’ survival rates, they have also been associated with various autoimmune toxicities, with the skin being most commonly affected. The severity of cutaneous toxicity can not only negatively affect patients’ quality of life but can also limit the proper treatment of cancer. Thus, the role of the dermatologist is substantial in early detecting and promptly treating these adverse events. Maculopapular rash, psoriasiform, lichenoid dermatoses and bullous pemphigoid are the most frequent cutaneous adverse events that require immediate intervention. Other rare autoimmune toxicities, e.g., sarcoidosis, dermatomyositis or subacute lupus, have also been reported. In this review, we summarize the aspects of ICB-induced cutaneous toxicities in patients with melanoma, emphasizing their management and treatment options in clinical practice.

Nail Apparatus Melanoma: Current Management and Future Perspectives

Nail apparatus melanoma (NAM) is a rare type of cutaneous melanoma that belongs to the acral melanoma subtype. NAM is managed principally in accordance with the general treatment for cutaneous melanoma, but there is scarce evidence in support of this in the literature. Acral melanoma is genetically different from non-acral cutaneous melanoma, while recently accumulated data suggest that NAM also has a different genetic background from acral melanoma. In this review, we focus on recent advances in the management of NAM. Localized NAM should be surgically removed; amputation of the digit and digit-preserving surgery have been reported. Sentinel lymph node biopsy can be considered for invasive NAM for the purpose of accurate staging. However, it is yet to be clarified whether patients with metastatic sentinel lymph nodes can be safely spared completion lymph node dissection. Similar to cutaneous melanoma, immune checkpoint inhibitors and BRAF/MEK inhibitors are used as the first-line treatment for metastatic NAM, but data on the efficacy of these therapies remain scarce. The therapeutic effects of immune checkpoint inhibitors could be lower for NAM than for cutaneous melanoma. This review highlights the urgent need to accumulate data to better define the optimal management of this rare melanoma.

Survival Mechanisms of Metastatic Melanoma Cells: The Link between Glucocorticoids and the Nrf2-Dependent Antioxidant Defense System

Circulating glucocorticoids increase during stress. Chronic stress, characterized by a sustained increase in serum levels of cortisol, has been associated in different cases with an increased risk of cancer and a worse prognosis. Glucocorticoids can promote gluconeogenesis, mobilization of amino acids, fat breakdown, and impair the body's immune response. Therefore, conditions that may favor cancer growth and the acquisition of radio- and chemo-resistance. We found that glucocorticoid receptor knockdown diminishes the antioxidant protection of murine B16-F10 (highly metastatic) melanoma cells, thus leading to a drastic decrease in their survival during interaction with the vascular endothelium. The BRAF^V600E mutation is the most commonly observed in melanoma patients. Recent studies revealed that VMF/PLX40-32 (vemurafenib, a selective inhibitor of mutant BRAF^V600E) increases mitochondrial respiration and reactive oxygen species (ROS) production in BRAF^V600E human melanoma cell lines. Early-stage cancer cells lacking Nrf2 generate high ROS levels and exhibit a senescence-like growth arrest. Thus, it is likely that a glucocorticoid receptor antagonist (RU486) could increase the efficacy of BRAF-related therapy in BRAF^V600E-mutated melanoma. In fact, during early progression of skin melanoma metastases, RU486 and VMF induced metastases regression. However, treatment at an advanced stage of growth found resistance to RU486 and VMF. This resistance was mechanistically linked to overexpression of proteins of the Bcl-2 family (Bcl-xL and Mcl-1 in different human models). Moreover, melanoma resistance was decreased if AKT and NF-κB signaling pathways were blocked. These findings highlight mechanisms by which metastatic melanoma cells adapt to survive and could help in the development of most effective therapeutic strategies.