Melanoma Infiltration Research Articles

A machine learning model reveals expansive downregulation of ligand-receptor interactions that enhance lymphocyte infiltration in melanoma with developed resistance to immune checkpoint blockade

Immune checkpoint blockade (ICB) is a promising cancer therapy; however, resistance frequently develops. To explore ICB resistance mechanisms, we develop Immunotherapy Resistance cell-cell Interaction Scanner (IRIS), a machine learning model aimed at identifying cell-type-specific tumor microenvironment ligand-receptor interactions relevant to ICB resistance. Applying IRIS to deconvolved transcriptomics data of the five largest melanoma ICB cohorts, we identify specific downregulated interactions, termed resistance downregulated interactions (RDI), as tumors develop resistance. These RDIs often involve chemokine signaling and offer a stronger predictive signal for ICB response compared to upregulated interactions or the state-of-the-art published transcriptomics biomarkers. Validation across multiple independent melanoma patient cohorts and modalities confirms that RDI activity is associated with CD8 + T cell infiltration and highly manifested in hot/brisk tumors. This study presents a strongly predictive ICB response biomarker, highlighting the key role of downregulating chemotaxis-associated ligand-receptor interactions in inhibiting lymphocyte infiltration in resistant tumors.

Prognosis and immunotherapy in melanoma based on selenoprotein k-related signature

Selenium and selenoproteins are closely related to melanoma progression. However, it is unclear how SELENOK affects lipid metabolism, endoplasmic reticulum stress (ERS), immune cell infiltration, survival, and prognosis in melanoma patients. Transcriptome data from melanoma patients was used to investigate SELENOK levels and their effect on prognosis, followed by an investigation of SELENOK’s effects on immune cell infiltration. Furthermore, a risk model based on ERS, lipid metabolism, and immune-related genes was constructed, and its utility in melanoma prognosis was evaluated. Finally, the drug sensitivity of the risk model was analyzed to provide a reference for melanoma therapy. The results showed that melanoma with a high SELENOK level had a greater degree of immune cell infiltration and a better prognosis. Additionally, SELENOK was found to regulate ERS, lipid metabolism, and immune cell infiltration in melanoma. The risk model based on SELENOK signature genes successfully predicted the prognosis of melanoma, and the low-risk group exhibited a favorable immunological microenvironment. Furthermore, high-risk patients with melanoma were candidates for chemotherapy with RAS pathway inhibitors, whereas low-risk patients were more susceptible to routinely used chemotherapy medicines. In summary, SELENOK was shown to regulate ERS, lipid metabolism, and immune cell infiltration in melanoma, and SELENOK was positively associated with the prognosis of melanoma. The risk model based on SELENOK signature genes was valuable for melanoma prognosis and therapy.

Tumor Immune Infiltration and Clinical Impact of Specific BCG-Related Genes in Melanoma.

Melanoma, caused by malignant melanocytes, is known for its invasiveness and poor prognosis. Therapies are often ineffective due to their heterogeneity and resistance. Bacillus Calmette-Guérin (BCG), primarily a tuberculosis vaccine, shows potential in treating melanoma by activating immune responses. In this study, data from The Cancer Genome Atlas and the NCBI GEO database were utilized to determine pivotal differentially expressed genes (DEGs) such as DSC2, CXCR1, BOK, and CSTB, which are significantly upregulated in BCG treated blood samples and are strongly associated with the prognosis of melanoma. We employ tools like edgeR and ggplot2 for functional and pathway analysis and develop a prognostic model using LASSO Cox regression analysis to predict patient survival. A notable finding is the correlation between BCG-related genes and immune cell infiltration in melanoma, highlighting the potential of these genes as both biomarkers and therapeutic targets. Additionally, the study examines genetic alterations in these genes and their impact on the disease. This study highlights the necessity of further exploring BCG-related genes for insights into melanoma pathogenesis and treatment enhancement, suggesting that BCG's role in immune activation could offer novel therapeutic avenues in cancer treatment.

Interleukin-4 induced 1-mediated resistance to an immune checkpoint inhibitor through suppression of CD8+ T cell infiltration in melanoma.

Cancer cells adopt multiple strategies to escape tumor surveillance by the host immune system and aberrant amino acid metabolism in the tumor microenvironment suppresses the immune system. Among the amino acid-metabolizing enzymes is an L-amino-acid oxidase called interleukin-4 induced 1 (IL4I1), which depletes essential amino acids in immune cells and is associated with a poor prognosis in various cancer types. Although IL4I1 is involved in immune metabolism abnormalities, its effect on the therapeutic efficacy of immune checkpoint inhibitors is unknown. In this study, we established murine melanoma cells overexpressing IL4I1 and investigated their effects on the intratumor immune microenvironment and the antitumor efficacy of anti-programmed death-ligand 1 (PD-L1) antibodies (Abs)in a syngeneic mouse model. As a result, we found that IL4I1-overexpressing B16-F10-derived tumors showed resistance to anti-PD-L1 Ab therapy. Transcriptome analysis revealed that immunosuppressive genes were globally upregulated in the IL4I1-overexpressing tumors. Consistently, we showed that IL4I1-overexpressing tumors exhibited an altered subset of lymphoid cells and particularly significant suppression of cytotoxic T cell infiltration compared to mock-infected B16-F10-derived tumors. After treatment with anti-PD-L1 Abs, we also found a more prominent elevation of tumor-associated macrophage (TAM) marker, CD68, in the IL4I1-overexpressing tumors than in the mock tumors. Consistently, we confirmed an enhanced TAM infiltration in the IL4I1-overexpressing tumors and a functional involvement of TAMs in the tumor growth. These observations indicate that IL4I1 reprograms the tumor microenvironment into an immunosuppressive state and thereby confers resistance to anti-PD-L1 Abs.

Immune Infiltrate Profiling of Cutaneous Melanoma with Spatial Transcriptomics

Background and Objective:In 2023, an estimated 97,610 melanomas will be diagnosed in the U.S. Immunotherapy has revolutionized care for melanoma patients and highlighted the prognostic value of characterizing immune infiltrates in melanoma tissue. This project used spatial transcriptomics (ST) to analyze immune infiltrates in cutaneous melanoma specimens.
 Methods:Visium Spatial Gene Expression platform generated datasets from formalin fixed paraffin embedded cutaneous melanoma specimens were analyzed using Loupe Browser software v6.5.0 (10x Genomics Inc.). Unsupervised clustering and manual region selection identified areas enriched in immune cell specific differentially expressed genes (DEGs). The transcript for Collagen alpha-1(XIX) chain (COL19A1) was identified as a DEG co-expressed with B cell marker DEGs. Fluorescence activated cell sorting was used to isolate primary B and T cells from mouse secondary lymphoid organs and human peripheral blood mononuclear cells to measure COL19A1 with quantitative PCR (qPCR).
 Results:Transcripts for CD19 (B cell marker) were concentrated in an immune DEG- rich region adjacent to a melanoma micrometastasis in one specimen. There was overlap between the tertiary lymphoid structure [TLS] markers SELL, CXCR5, CCR7, and CXCL13 with CD19 and/or COL19A1. Though qPCR revealed minimal Col19a1 in mouse B and T cells, COL19A1 was abundant and specific for human B cells.
 Conclusions & Potential Impact:This study demonstrates the feasibility and potential of using ST to characterize immune cell infiltrates in melanoma. Though COL19A1 expression is typically understood to be enriched in muscle and neuronal cells, the studies presented here suggest this transcript could be a novel human (but not mouse) B cell marker. Future studies are needed to determine if collagen XIX (protein) is expressed in B cells and if it is, what the biological functions of this protein are in B cells under physiologic and pathologic (e.g. melanoma) conditions.

Identification of immune-related genes and integrated analysis of immune-cell infiltration in melanoma.

This study was conducted to screen out immune-related genes in connection with the prognosis of melanoma, construct a prognosis model and explore the relevant mechanisms. 1973 genes associated with immune system were derived from the Immport database, and RNA-seq data of melanoma and information of patients were searched from the Xena database. Cox univariate analysis, Lasso analysis and Cox multivariate analysis were used to screen out six genes to construct the model. Then the risk scores were estimated for patients based on our constructed prognosis model. Estimate was used to affirm that the model was about immune infiltration, and CIBERSORT was used to screen out immune cells associated with prognosis. TIDE was applied to predict the efficacy of immunotherapy. Finally, GSE65904 and GSE19234 were used to confirm the effectiveness of the model. ADCYAP1R1, GPI, NTS might cause poor prognosis while IFITM1, KIR2DL4, LIF were more likely conductive to prognosis of melanoma patients and a model of prognosis was constructed on the basis of these six genes. The effectiveness of the model has been proven by the ROC curve, and the miRNAs targeting the screened genes were found out, suggesting that the immune system might impact on the prognosis of melanoma by T cell CD8+, T cell CD4+ memory and NK cells. In this study, the screened six genes were associated with the prognosis of melanoma, which was conductive to clinical prognostic prediction and individualized treatment strategy.

HRS mediates tumor immune evasion by regulating proteostasis-associated interferon pathway activation

By sorting receptor tyrosine kinases into endolysosomes, the endosomal sorting complexes required for transport (ESCRTs) are thought to attenuate oncogenic signaling in tumor cells. Paradoxically, ESCRT members are upregulated in tumors. Here, we show that disruption of hepatocyte growth factor-regulated tyrosine kinase substrate (HRS), a pivotal ESCRT component, inhibited tumor growth by promoting CD8+ Tcell infiltration in melanoma and colon cancer mouse models. HRS ablation led to misfolded protein accumulation and triggered endoplasmic reticulum (ER) stress, resulting in the activation of the type I interferon pathway in an inositol-requiring enzyme-1α (IRE1α)/X-box binding protein 1 (XBP1)-dependent manner. HRS was upregulated in tumor cells with high tumor mutational burden (TMB). HRS expression associates with the response to PD-L1/PD-1 blockade therapy in melanoma patients with high TMB tumors. HRS ablation sensitized anti-PD-1 treatment in mouse melanoma models. Our study shows a mechanism by which tumor cells with high TMB evade immune surveillance and suggests HRS as a promising target to improve immunotherapy.

Radiotherapy combined with immunotherapy could improve the immune infiltration of melanoma in mice and enhance the abscopal effect.

To analyze the gene mutation, immune infiltration and tumor growth of primary tumor and distant tumor under different treatment modes. Twenty B16 murine melanoma cells were injected subcutaneously into the of both sides of the thigh, simulating a primary tumor and a secondary tumor impacted by the abscopal effect, respectively. They were divided into blank control group, immunotherapy group, radiotherapy group, and radiotherapy combined immunotherapy group. During this period, tumor volume was measured, and RNA sequencing was performed on tumor samples after the test. R software was used to analyze differentially expressed genes, functional enrichment, and immune infiltration. We found that any treatment mode could cause changes in differentially expressed genes, especially the combination treatment. The different therapeutic effects might be caused by gene expression. In addition, the proportions of infiltrating immune cells in the irradiated and abscopal tumors were different. In the combination treatment group, T-cell infiltration in the irradiated site was the most obvious. In the immunotherapy group, CD8+ T-cell infiltration in the abscopal tumor site was obvious, but immunotherapy alone might have a poor prognosis. Whether the irradiated or abscopal tumor was evaluated, radiotherapy combined with anti-programmed cell death protein 1 (anti-PD-1) therapy produced the most obvious tumor control and might have a positive impact on prognosis. Combination therapy not only improves the immune microenvironment but may also have a positive impact on prognosis.

ITGAL as a prognostic biomarker correlated with immune infiltrates in melanoma.

This study investigates the relationship between ITGAL expression and immune infiltration, clinical prognosis, and specific types of T cells in melanoma tissue. The findings reveal the key role of ITGAL in melanoma and its potential mechanism of regulating tumor immune infiltrating cells, highlighting its potential as a diagnostic biomarker and therapeutic target for advanced melanoma.

Identification of CRKL as an oncogenic biomarker for prognosis and immunotherapy in melanoma, and its potential molecular mechanism

CRKL (CRK Like Proto-Oncogene) belongs to the Crk family and is a 39-kDa adapter protein that encodes SH2 and SH3 (src homologs) domains. To identify its oncogenic role in malignant melanoma, we investigated the association between CRKL and mutation, prognosis, tumor mutation burden, immune cell infiltration of melanoma, and explored the associations between CRKL and immunotherapy response. Our results showed that abnormal CRKL expression is associated with poor prognosis in melanoma and is significantly correlated with immune-activated pathways and processes, immune cell infiltrations, and expression of immunoregulators. Importantly, we found that CRKL expression is a predictive biomarker for anti-PD1 therapy response in melanoma patients. Furthermore, inhibiting CRKL expression in melanoma cell lines suppressed their proliferation and metastasis, as well as activated the pyroptosis-related pathway. Our study provides potential mechanisms of melanoma pathogenesis, which may suggest new avenues for targeted therapy in this disease.

Melittin derived peptide-drug conjugate, M-DM1, inhibits tumor progression and induces effector cell infiltration in melanoma by targeting M2 tumor-associated macrophages.

Melanoma has the highest mortality rate among all the types of skin cancer. In melanoma, M2-like tumor-associated macrophages (TAMs) are associated with the invasiveness of tumor cells and a poor prognosis. Hence, the depletion or reduction of M2-TAMs is a therapeutic strategy for the inhibition of tumor progression. The aim of this study was to evaluate the therapeutic effects of M-DM1, which is a conjugation of melittin (M), as a carrier for M2-like TAMs, and mertansine (DM1), as a payload to induce apoptosis of TAMs, in a mouse model of melanoma. Melittin and DM1 were conjugated and examined for the characterization of M-DM1 by high-performance liquid chromatography and electrospray ionization mass spectrometry. Synthesized M-DM1 were examined for in vitro cytotoxic effects. For the in vivo study, we engrafted murine B16-F10 into right flank of C57BL/6 female mice and administered an array of treatments (PBS, M, DM1, or M-DM1 (20 nmol/kg)). Subsequently, the tumor growth and survival rates were analyzed, as well as examining the phenotypes of tumor-infiltrating leukocytes and expression profiles. M-DM1 was found to specifically reduce M2-like TAMs in melanoma, which potentially leads to the suppression of tumor growth, migration, and invasion. In addition, we also found that M-DM1 improved the survival rates in a mouse model of melanoma compared to M or DM1 treatment alone. Flow cytometric analysis revealed that M-DM1 enhanced the infiltration of CD8+ cytotoxic T cells and natural killer cells (NK cells) in the tumor microenvironment. Taken together, our findings highlight that M-DM1 is a prospective agent with enhanced anti-tumor effects.

MMP2 is a immunotherapy related biomarker and correlated with cancer-associated fibroblasts infiltrate in melanoma

BackgroundMounting evidence supports that matrix metalloproteinase (MMPs) are highly associated with tumor progression and that targeting MMPs may overcome the barrier of immune suppression. Among these, whether MMP2 functions as an immunosuppressive role in melanoma, remains unclear.MethodsThe Cancer Genome Atlas (TCGA) and Gene Expression Profiling Interactive Analysis 2 (GEPIA2) databases were used to assess the prognosis of MMP2 in melanoma, after which Tumor immune estimation resource (TIMER) was used to explore the relationship between MMP2 expression and cancer associated fibroblasts (CAFs) infiltration. Finally, we evaluated the efficacy of MMP2 inhibitor on CAFs infiltration and immunotherapy using a mouse melanoma model.ResultsIn general, the expression of MMP2, MMP13, MMP16, MMP17 and MMP25 were significantly associated with skin cutaneous melanoma (SKCM) patients prognosis, among which MMP2 low expression benefited patients the most. Especially, the overall survival (OS) of BRAF mutation patients with high MMP2 expression was significantly lower than the MMP2 low expression group, but there was no significant difference in BRAF wild-type patients. KEGG and GO enrichment analysis indicated that MMP2 related genes were mostly associated with extracellular structure organization, collagen-containing extracellular matrix and extracellular matrix structural constituent. Furthermore, in almost all cancers, MMP2 expression was positively correlated with CAFs infiltration. MMP2 inhibitor works synergistically with PD-1 antibody and induces tumor regression in a mouse melanoma model, which is dependent on decreased CAFs infiltration.ConclusionsThis suggests that MMP2 plays a vital role in the regulation of CAFs infiltration, potentially participating in immunotherapy response, and thus representing a valuable target of immunotherapy in melanoma.

Low Expression of CLEC2B Indicates Poor Prognosis in Melanoma.

Melanoma is a highly malignant skin tumor with a poor prognosis. Identification of novel biomarkers might potentially reveal the underlying mechanisms of melanoma progression. We demonstrated the relationship between pan-cancer CLEC2B expression and melanoma samples in The Cancer Genome Atlas (TCGA) database. Next, the Kaplan-Meier plot and Cox regression analysis determined the prognostic value of CLEC2B in melanoma. Biological pathway enrichment was screened by Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA), enabling the correlation analysis between the immune infiltration level and CLEC2B expression in melanoma. Our final claim was validated using qPCR, immunohistochemistry, Western blot, cell colony formation assays, ethynyldeoxyuridine (Edu) analysis, and cell Invasion assays. Our study revealed that the high CLEC2B expression correlates with poor overall survival of melanoma patients. Moreover, a low expression of CLEC2B was found in the A375 cell line. In addition, CLEC2B has significant prognostic value in melanoma diagnosis, with an AUC of 0.896. Prognostic analysis showed the low expression of CLEC2B to be independently associated with melanoma patients. Moreover, the expression of CLEC2B was significantly correlated with B cells, eosinophils, macrophages, neutrophils, NK cells, T helper cells, Tregs, Th1 cells, Th17 cells, and Th2 cells. PCR and immunohistochemistry indicated CLEC2B to be significantly downregulated in melanoma. The cell colony formation assay showed CLEC2B knockout increased the proliferation of A375 cells. Our study established low levels of CLEC2B to be poor prognostic markers, enabling immunosuppressive cell infiltration in melanoma.

Ultrasonographic Assessment of Depth Infiltration in Melanoma and Non-melanoma Skin Cancer.

The preoperative assessment of infiltration depth in melanoma and non-melanoma skin cancer by means of high-frequency ultrasound (≥18 MhZ) is essential for optimizing the therapeutic approach in our patients. Often, histologically confirmed skin tumors are directly referred to surgical departments for resection, and sonography is increasingly helping us identify those subjects who are no longer candidates for extensive surgical interventions. In cases of deep tumor infiltration, with potential surgical failure e.g. impairment of the quality of life and significant esthetic and functional complications, preoperative sonography can guide the surgeon to withstand from an operation and decide instead in favor of less mutilating radiooncological or medical treatment options. Furthermore, in melanoma patients, the preoperative knowledge of the tumor depth is essential for the determination of the therapeutic approach, the correct safety margins and the need of a sentinelnode biopsy. We herein encourage the use of preoperative sonography in dermatologic surgery whenever possible as it represents an easy, painless, "in vivo" method, which provides clinicians with significant clinical information that can influence the therapy and improve patient compliance.

CEACAM1 is a direct SOX10 target and inhibits melanoma immune infiltration and stemness.

SOX10 is a key regulator of melanoma progression and promotes a melanocytic/differentiated state. Here we identified melanoma cell lines lacking SOX10 expression which retain their invivo growth capabilities. More importantly, we find that SOX10 can regulate T-cell infiltration in melanoma while also decreasing common cancer stem cell (CSC) properties. We show that SOX10 regulates CEACAM1, a surface protein with immunomodulatory properties. SOX10 directly binds to a distal CEACAM1 promoter region approximately 3-4kbps from the CEACAM1 transcriptional start site. Furthermore, we show that a SOX10-CEACAM1 axis can suppress CD8+ T-cell infiltration as well as reduce CSC pool within tumors, leading to reduced tumor growth. Overall, these results identify SOX10 as a direct regulator of CEACAM1, and uncover both a pro- and anti-tumorigenic roles for SOX10 in melanoma.

Comprehensive Analysis of Cuproptosis-Related Genes in Immune Infiltration and Prognosis in Melanoma.

Skin cutaneous melanoma (SKCM, hereafter referred to as melanoma) is the most lethal skin cancer with increasing incidence. Regulated cell death plays an important role in tumorigenesis and serves as an important target for almost all treatment strategies. Cuproptosis is the most recently identified copper-dependent regulated cell death form that relies on mitochondria respiration. However, its role in tumorigenesis remains unknown. The correlation of cuproptosis-related genes with tumor prognosis is far to be understood, either. In the present study, we explored the correlation between cuproptosis-related genes with the prognosis of melanoma by accessing and analyzing a public database and found 11 out 12 genes were upregulated in melanoma tissues and three genes (LIPT1, PDHA1, and SLC31A1) have predictive value for the prognosis. The subgroup of melanoma patients with higher cuproptosis-related gene expression showed longer overall survival than those with lower gene expression. We chose LIPT1 for further exploration. LIPT1 expression was increased in melanoma biopsies and was an independent favorable prognostic indicator for melanoma patients. Moreover, LIPT1 expression was positively correlated with PD-L1 expression and negatively associated with Treg cell infiltration. The melanoma patients with higher LIPT1 expression showed longer overall survival than those with lower LIPT1 expression after receiving immunotherapy, indicating the prognostic predictive value of LIPT1. Finally, a pan-cancer analysis indicated that LIPT1 was differentially expressed in diverse cancers as compared to normal tissues and correlated with the expression of multiple immune checkpoints, especially PD-L1. It could serve as a favorable prognosis indicator in some cancer types. In conclusion, our study demonstrated the prognostic value of cuproptosis-related genes, especially LIPT1, in melanoma, and revealed the correlation between LIPT1 expression and immune infiltration in melanoma, thus providing new clues on the prognostic assessment of melanoma patients and providing a new target for the immunotherapy of melanoma.

DIRAS2 Is a Prognostic Biomarker and Linked With Immune Infiltrates in Melanoma.

BackgroundSkin cutaneous melanoma (SKCM) is a highly malignant skin tumor. DIRAS2 is considered to be a tumor suppressor gene; however, its function in SKCM has not been explored.MethodsThe Gene Expression Profiling Interactive Analysis (GEPIA) was implemented to investigate the expression of DIRAS2 in SKCM, and plot the survival curve to determine the effect of DIRAS2 on the survival rates of SKCM patients. Then, the correlation between DIRAS2 and tumor immune infiltration was also discussed, and the expression of DIRAS2 and immune infiltration level in SKCM immune cells was determined using TIMER. The top 100 genes most associated with DIRAS2 expression were used for functional enrichment analysis. In order to confirm the anti-cancer effects of DIRAS2 in SKCM in the data analysis, in vitro assays as well as in vivo studies of DIRAS2 on SKCM tumor cell proliferation, migration, invasion, and metastasis were conducted. Western blot and immunofluorescence assay were employed to study the relationship between DIRAS2 and Wnt/β-catenin signaling pathway in SKCM.ResultsDIRAS2 expression was shown to be significantly correlated with tumor grade using univariate logistic regression analysis. DIRAS2 was found to be an independent prognostic factor for SKCM in multivariate analysis. Of note, DIRAS2 expression levels were positively correlated with the infiltration levels of B cells, CD4+ T cells, and CD8+ T cells in SKCM. The infiltration of B cells, CD4+ T cells, and CD8+ T cells was positively correlated with the cumulative survival rate of SKCM patients. In vitro experiments suggested that proliferation, migration, invasion, and metastasis of SKCM tumor cells were distinctly enhanced after DIRAS2 knockdown. Furthermore, DIRAS2 depletion promoted melanoma growth and metastasis in vivo. As for the mechanism, silencing DIRAS2 can activate the signal transduction of the Wnt/β-catenin signaling pathway.ConclusionDIRAS2 functions as a tumor suppressor gene in cases of SKCM by inhibiting the Wnt/β-catenin signaling. It is also associated with immune infiltration in SKCM.

Vaccination against galectin-1 promotes cytotoxic T-cell infiltration in melanoma and reduces tumor burden

Galectin-1 (Gal1) is a glycan-binding protein that promotes tumor progression by several distinct mechanisms. Through direct binding to vascular endothelial growth factor (VEGF)-receptor 2, Gal1 is able to induce VEGF-like signaling, which contributes to tumor angiogenesis. Furthermore, several studies have demonstrated an immunosuppressive function of Gal1 through effects on both effector and regulatory T cells. Elevated Gal1 expression and secretion have been shown in many tumor types, and high Gal1 serum levels have been connected to poor prognosis in cancer patients. These findings suggest that therapeutic strategies directed against Gal1 would enable simultaneous targeting of angiogenesis, immune evasion and metastasis. In the current study, we have analyzed the potential of Gal1 as a cancer vaccine target. We show that it is possible to generate high anti-Gal1 antibody levels in mice immunized with a recombinant vaccine protein consisting of bacterial sequences fused to Gal1. Growth of Gal1 expressing melanomas was significantly impaired in the immunized mice compared to the control group. This was associated with improved perfusion of the tumor vasculature, as well as increased infiltration of macrophages and cytotoxic T cells (CTLs). The level of granzyme B, mainly originating from CTLs in our model, was significantly elevated in Gal1 vaccinated mice and correlated with a decrease in tumor burden. We conclude that vaccination against Gal1 is a promising pro-immunogenic approach for cancer therapy that could potentially enhance the effect of other immunotherapeutic strategies due to its ability to promote CTL influx in tumors.

Rocaglamide promotes the infiltration and antitumor immunity of NK cells by activating cGAS-STING signaling in non-small cell lung cancer.

Background: Natural killer (NK) cell-based immunotherapy is clinically limited due to insufficient tumor infiltration in solid tumors. We have previously found that the natural product rocaglamide (RocA) can enhance NK cell-mediated killing of non-small cell lung cancer (NSCLC) cells by inhibiting autophagy, and autophagic inhibition has been shown to increase NK cell tumor infiltration in melanoma. Therefore, we hypothesized that RocA could increase NK cell infiltration in NSCLC by autophagy inhibition.Methods: Flow cytometry, RNA-sequencing, real-time PCR, Western blotting analysis, and xenograft tumor model were utilized to assess the infiltration of NK cells and the underlying mechanism.Results: RocA significantly increased the infiltration of NK cells and the expressions of CCL5 and CXCL10 in NSCLC cells, which could not be reversed by the inhibitions of autophagy/ULK1, JNK and NF-κB. However, such up-regulation could be suppressed by the inhibitions of TKB1 and STING. Furthermore, RocA dramatically activated the cGAS (cyclic GMP-AMP synthase)-STING (stimulator of interferon genes) signaling pathway, and the inhibition/depletion of STING ablated the up-regulation of CCL5 and CXCL10, NK cell infiltration, and tumor regression induced by RocA. Besides, RocA damaged mitochondrial DNA (mtDNA) and promoted the cytoplasmic release of mtDNA. The mPTP inhibitor cyclosporin A could reverse RocA-induced cytoplasmic release of mtDNA.Conclusions: RocA could promote NK cell infiltration by activating cGAS-STING signaling via targeting mtDNA, but not by inhibiting autophagy. Taken together, our current findings suggested that RocA was a potent cGAS-STING agonist and had a promising potential in cancer immunotherapy, especially in NK cell-based immunotherapy.

Identification of an m6A Regulators-Mediated Prognosis Signature For Survival Prediction and Its Relevance to Immune Infiltration in Melanoma.

Despite robust evidence for the role of m6A in cancer development and progression, its association with immune infiltration and survival outcomes in melanoma remains obscure. Here, we aimed to develop an m6A-related risk signature to improve prognostic and immunotherapy responder prediction performance in the context of melanoma. We comprehensively analyzed the m6A cluster and immune infiltration phenotypes of public datasets. The TCGA (n = 457) and eleven independent melanoma cohorts (n = 758) were used as the training and validation datasets, respectively. We identified two m6A clusters (m6A-clusterA and m6A-clusterB) based on the expression pattern of m6A regulators via unsupervised consensus clustering. IGF2BP1 (7.49%), KIAA1429 (7.06%), and YTHDC1 (4.28%) were the three most frequently mutated genes. There was a correlation between driver genes mutation statuses and the expression of m6A regulators. A significant difference in tumor-associated immune infiltration between two m6A clusters was detected. Compared with m6A-clusterA, the m6A-clusterB was characterized by a lower immune score and immune cell infiltration but higher mRNA expression-based stemness index (mRNAsi). An m6A-related risk signature consisting of 12 genes was determined via Cox regression analysis and divided the patients into low- and high-risk groups (IL6ST, MBNL1, NXT2, EIF2A, CSGALNACT1, C11orf58, CD14, SPI1, NCCRP1, BOK, CD74, PAEP). A nomogram was developed for the prediction of the survival rate. Compared with the high-risk group, the low-risk group was characterized by high expression of immune checkpoints and immunophenoscore (IPS), activation of immune-related pathways, and more enriched in immune cell infiltrations. The low-risk group had a favorable prognosis and contained the potential beneficiaries of the immune checkpoint blockade therapy and verified by the IMvigor210 cohort (n = 298). The m6A-related signature we have determined in melanoma highlights the relationships between m6A regulators and immune cell infiltration. The established risk signature was identified as a promising clinical biomarker of melanoma.