Antibody therapies for melanoma: new and emerging opportunities to activate immunity (Review)

MXene-Polydopamine-antiCEACAM1 Antibody Complex as a Strategy for Targeted Ablation of Melanoma

Photothermal therapy (PTT) is a method for eradicating tumor tissues through the use of photothermal materials and photosensitizing agents that absorb light energy from laser sources and convert it into heat, which selectively targets and destroys cancer cells while sparing healthy tissue. MXenes have been intensively investigated as photosensitizing agents for PTT. However, achieving the selectivity of MXenes to the tumor cells remains a challenge. Specific antibodies (Ab) against tumor antigens can achieve homing of the photosensitizing agents toward tumor cells, but their immobilization on MXene received little attention. Here, we offer a strategy for the selective ablation of melanoma cells using MXene-polydopamine-antiCEACAM1 Ab complexes. We coated Ti3C2Tx MXene with polydopamine (PDA), a natural compound that attaches Ab to the MXene surface, followed by conjugation with an anti-CEACAM1 Ab. Our experiments confirm the biocompatibility of the Ti3C2Tx-PDA and Ti3C2Tx-PDA-antiCEACAM1 Ab complexes across various cell types. We also established a protocol for the selective ablation of CEACAM1-positive melanoma cells using near-infrared irradiation. The obtained complexes exhibit high selectivity and efficiency in targeting and eliminating CEACAM1-positive melanoma cells while sparing CEACAM1-negative cells. These results demonstrate the potential of MXene-PDA-Ab complexes for cancer therapy. They underline the critical role of targeted therapies in oncology, offering a promising avenue for the precise and safe treatment of melanoma and possibly other cancers characterized by specific biomarkers. Future research will aim to refine these complexes for clinical use, paving the way for new strategies for cancer treatment.

Release of Exosomal PD-L1 in Bone and Soft Tissue Sarcomas and Its Relationship to Radiotherapy

(1) Background: Exosomal PD-L1 has garnered attention owing to its role in instigating systemic immune suppression. The objective of this study is to elucidate whether bone and soft tissue sarcoma cells possess the capacity to secrete functionally active exosomal PD-L1 and whether radiotherapy (RT) induces the exosomal PD-L1 release. (2) Methods: Human osteosarcoma cell line 143B and human fibrosarcoma cell line HT1080 were utilized. Exosomes were isolated from the culture medium and blood via ultracentrifugation. The expression of PD-L1 on both tumor cells and exosomes was evaluated. The inhibitory effect on PBMC was employed to assess the activity of exosomal PD-L1. Post radiotherapy, changes in PD-L1 expression were compared. (3) Results: Exosomal PD-L1 was detected in the culture medium of tumor cells but was absent in the culture medium of PD-L1 knockout cells. Exosomal PD-L1 exhibited an inhibitory effect on PBMC activation. In tumor-bearing mice, human-derived exosomal PD-L1 was detected in the bloodstream. Following radiotherapy, tumor cells upregulated PD-L1, and human-derived exosomal PD-L1 were detected in the bloodstream. (4) Conclusions: Exosomal PD-L1 emanates from bone and soft tissue sarcoma cells and is disseminated into the circulatory system. The levels of PD-L1 in tumor cells and the release of exosomal PD-L1 were augmented after irradiation with RT.

Immunotherapy for endometrial cancer

Advanced recurrent endometrial cancer (EC) has a poor prognosis and new treatment options are needed. In 2013, EC was classified by genomic analysis into four groups: the POLE ultra-mutated group, the MSI-high hypermutated group (MSI-H), the copy number low group, and the copy number high group. The prognosis differs based on the classification, which should enable the individualization of treatment. The MSI-H and POLE types can induce PD-L1 expression in cancer cells. Among the gynecological cancers, EC exhibits the highest levels of PD-1 and PD-L1 expression and has the highest proportion of MSI-H. Thus, an immune checkpoint inhibitor (ICI) is expected to be effective. The first ICI to show efficacy in recurrent EC was the anti-PD1 antibody pembrolizumab, which exhibited efficacy in MSI-H EC. The combination of pembrolizumab and the multi-kinase inhibitor lenvatinib significantly prolongs OS/PFS compared with single-agent chemotherapy in previously treated recurrent EC, regardless of MSI status. ICIs are now moving from second-line and beyond to first-line treatment regimens. The efficacy of paclitaxel plus carboplatin (TC) and ICI combinations compared with TC have been demonstrated, including an ongoing Phase III trial comparing chemotherapy with the combination of pembrolizumab and lenvatinib. Although ICIs are becoming the mainstay of EC, they cause systemic inflammatory side effects known as irAEs. The incidence of irAEs is higher for combination therapy with CT or lenvatinib compared with ICI therapy alone. Even though they are rarely fatal, irAEs should be addressed promptly.

Association of immune checkpoint inhibitors with SARS-CoV-2 infection rate and prognosis in patients with solid tumors: a systematic review and meta-analysis

The rate and prognosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in patients with solid cancer tumors actively treated with immune checkpoint inhibitors (ICIs) have not been fully determined. The goal of this meta-analysis was to explore this issue, which can be helpful to clinicians in their decision-making concerning patient treatment. We conducted a thorough search for relevant cohort studies in the databases PubMed, Embase, Cochrane Library, and Web of Science. Mortality and infection rate were the primary endpoints, and the incidence of severe or critical disease was the secondary result. A total of 6,267 cases (individual patients) were represented in 15 studies. Prior exposure to ICIs was not correlated with an elevated risk of SARS-CoV-2 infection (relative risk (RR) 1.04, 95% CI 0.57-1.88, z = 0.12, P = 0.905) or mortality (RR 1.22, 95% CI 0.99-1.50, z = 1.90, P = 0.057). However, the results of the meta-analysis revealed that taking ICIs before SARS-CoV-2 diagnosis increased the chance of developing severe or critical disease (RR 1.51, 95% CI 1.09-2.10, z = 2.46, P = 0.014). No significant inter-study heterogeneity was observed. The infection and mortality rates of SARS-CoV-2 in patients with solid tumors who previously received ICIs or other antitumor therapies did not differ significantly. However, secondary outcomes showed that ICIs treatment before the diagnosis of SARS-CoV-2 infection was significantly associated with the probability of severe or critical illness.

Systematic review registration

https://www.crd.york.ac.uk/prospero/#recordDetails PROSPERO, identifier CRD42023393511.

Impact of Nutritional Status on Neutrophil-to-Lymphocyte Ratio as a Predictor of Efficacy and Adverse Events of Immune Check-Point Inhibitors

The neutrophil -to-lymphocyte ratio (NLR) is useful for predicting the effectiveness of treatment with immune checkpoint inhibitors (ICIs) and immune-related adverse events (irAEs). Because a growing body of evidence has recently shown that the number of lymphocytes that comprise NLR fluctuates according to nutritional status, this study examined whether the usefulness of NLR varies in ICI treatment due to changes in nutritional status. A retrospective analysis was performed on 1234 patients who received ICI treatment for malignant tumors at our hospital. Progression-free survival (PFS) was significantly prolonged in patients with NLR < 4. Multivariate analysis revealed that the factors associated with the occurrence of irAE were NLR < 4 and the use of ipilimumab. However, when limited to cases with serum albumin levels <3.8 g/dL, lymphocyte counts significantly decreased, and the associations between NLR and PFS and between NLR and irAE occurrence disappeared. In contrast, when limited to the cases with serum albumin levels ≥3.8 g/dL, the associations remained, with significantly prolonged PFS and significantly increased irAE occurrence at NLR < 4. NLR may be a good predictive tool for PFS and irAE occurrence during ICI treatment when a good nutritional status is maintained.

Configuring Therapeutic Aspects of Immune Checkpoints in Lung Cancer

Immune checkpoints are unique components of the body's defense mechanism that safeguard the body from immune responses that are potent enough to harm healthy body cells. When proteins present on the surface of T cells recognize and bind to the proteins present on other tumor cells, immune checkpoints are triggered. These proteins are called immunological checkpoints. The T cells receive an on/off signal when the checkpoints interact with companion proteins. This might avert the host's immune system from eliminating cancer cells. The standard care plan for the treatment of non-small cell lung cancer (NSCLC) has been revolutionized with the use of drugs targeting immune checkpoints, in particular programmed cell death protein 1. These drugs are now extended for their potential to manage SCLC. However, it is acknowledged that these drugs have specific immune related adverse effects. Herein, we discuss the use of immune checkpoint inhibitors in patients with NSCLC and SCLC, their outcomes, and future perspectives.

Nicotinamide N-methyltransferase gene silencing enhances chemosensitivity of melanoma cell lines

Melanoma accounts for less than 5% of all cutaneous neoplasms but is responsible for the greater part of skin cancer-related deaths. Therefore, the identification of molecules that could serve as the therapeutic target is urgent. This study focused on the enzyme nicotinamide N-methyltransferase (NNMT). The effect of NNMT knockdown on cell proliferation and migration of A375 melanoma cells was evaluated by MTT and wound healing assays, respectively. Viability of A375 cells downregulating NNMT was also explored under treatment with dacarbazine, a chemotherapeutic drug approved for advanced melanoma treatment. The impact of enzyme knockdown on cell proliferation and chemosensitivity was also investigated in WM-115 melanoma cells. Results obtained demonstrated that NNMT silencing led to a significant reduction of cell proliferation and migration of A375 cells. Moreover, enzyme downregulation was associated with an increase of melanoma cells sensitivity to treatment with dacarbazine. Analogous effects induced by enzyme knockdown on cell proliferation and chemosensitivity were also found in the WM-115 cell line. Our data seem to demonstrate that NNMT could represent a promising molecular target for the effective treatment of this form of skin cancer.

Understanding relevant immune mechanisms in gastrointestinal oncology

Rapid and successful drug development has resulted in multiple treatment options for gastrointestinal cancer, requiring careful decision making for individual patients. The general theme in modern immunology is that the field is moving beyond establishing the fundamental principles of immune response mechanisms to applying these propositions to understand human diseases and develop new therapies. Immunotherapy has contributed enormously to cancer treatments with a virtual explosion in novel therapeutics including checkpoint inhibitors and other recently developed immunomodulators and the development of novel therapeutic approaches. Although the majority of gastrointestinal (GI) cancers are generally considered poorly immunogenic, clinical trials have revealed that some of the patients with various gastrointestinal cancers are highly responsive to immune checkpoint inhibition-based therapies. We paid special attention to the clinical relevance of immunology and emphasized how newly developed therapies work, including what their strengths and pitfalls are. This review aims to enhance the interest of practitioners in the many specialties and subspecialties that the discipline influences and to assist them in understanding this increasing complexity.

Antibody-Based Immunotherapy: Alternative Approaches for the Treatment of Metastatic Melanoma

Melanoma is the least common form of skin cancer and is associated with the highest mortality. Where melanoma is mostly unresponsive to conventional therapies (e.g., chemotherapy), BRAF inhibitor treatment has shown improved therapeutic outcomes. Photodynamic therapy (PDT) relies on a light-activated compound to produce death-inducing amounts of reactive oxygen species (ROS). Their capacity to selectively accumulate in tumor cells has been confirmed in melanoma treatment with some encouraging results. However, this treatment approach has not reached clinical fruition for melanoma due to major limitations associated with the development of resistance and subsequent side effects. These adverse effects might be bypassed by immunotherapy in the form of antibody–drug conjugates (ADCs) relying on the ability of monoclonal antibodies (mAbs) to target specific tumor-associated antigens (TAAs) and to be used as carriers to specifically deliver cytotoxic warheads into corresponding tumor cells. Of late, the continued refinement of ADC therapeutic efficacy has given rise to photoimmunotherapy (PIT) (a light-sensitive compound conjugated to mAbs), which by virtue of requiring light activation only exerts its toxic effect on light-irradiated cells. As such, this review aims to highlight the potential clinical benefits of various armed antibody-based immunotherapies, including PDT, as alternative approaches for the treatment of metastatic melanoma.

A Review of T-Cell Related Therapy for Osteosarcoma

Osteosarcoma is one of the most common primary malignant tumors of bone. The combination of chemotherapy and surgery makes the prognosis better than before, but therapy has not dramatically improved over the last three decades. This is partially because of the lack of a novel specialized drug for osteosarcoma, which is known as a tumor with heterogeneity. On the other hand, immunotherapy has been one of the most widely used strategies for many cancers over the last ten years. The therapies related to T-cell response, such as immune checkpoint inhibitor and chimeric antigen receptor T-cell therapy, are well-known options for some cancers. In this review, we offer the accumulated knowledge of T-cell-related immunotherapy for osteosarcoma, and discuss the future of the therapy.

Immune checkpoint inhibitors-induced autoimmunity: The impact of gender

OBJECTIVE

To evaluate prevalence and clinical features of immune-related adverse events (irAEs) to immune checkpoint inhibitors (ICIs) in accordance with the gender of treated cancer patients.

METHODS

A systematic review of the medical literature was conducted by searching all available clinical data up to December 2019 in several databases using a combination of MESH terms related to immune checkpoint inhibitors, autoimmunity, and gender. Analyzed data were related to all FDA approved ICIs and respective indications in cancer.

RESULTS

According to data from the literature, male display a slightly lower frequencies of ICIs-related endocrinopathies compared with females, specifically thyroid dysfunction. On the contrary, ICIs-hypophysitis has been reported at higher rates among males compared with females. ICI-induced Sicca/Sjogren's syndrome showed a more frequent occurrence in men than the idiopathic primary form. No differences in gender distribution seem to arise in hematologic and gastrointestinal-irAEs. Interestingly, the gender distribution of neurologic and vascular ICIs-irAEs appears male-dominant.

CONCLUSIONS

The present systematic review highlights for the first time that the distribution of patients experiencing irAEs associated with ICIs changes among the genders according to the specific drug used, the frequency of the cancer and of the autoimmune conditions in the general population.

DUPLICATE: Overall survival and PD-L1 expression in patients with recurrent or metastatic head and neck cancer treated with nivolumab

The Publisher regrets that this article is an accidental duplication of an article that has already been published, https://doi.org/10.1016/j.anl.2020.02.018. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.

Overall survival and PD-L1 expression in patients with recurrent or metastatic head and neck cancer treated with nivolumab

OBJECTIVE

Our facility measures programmed cell death ligand 1 (PD-L1) expression in all patients before administering nivolumab. The aim of the present study is to clarify the association between overall survival (OS) and PD-L1 expression.

PATIENTS AND METHODS

Subjects in this study were 52 patients with R/M-HNC cancer (45 men, 7 women) administered nivolumab in our facility between June 1, 2017 and January 31, 2019. Mean age was 62.2 years (median, 65 years; range, 28-81 years). Histopathological type was squamous cell carcinoma (SCC) in 48 cases, and non-SCC in 4 cases. We set OS as the primary endpoint and progression-free survival (PFS), overall response rate (ORR), association of OS and PD-L1 expression and association of PFS and PD-L1 expression as secondary endpoints. The cut-off for PD-L1 expression was set using the receiver operating characteristic (ROC) curve. We compared OS, PES and ORR using this PD-L1 cut-off for all patients and for the SCC group. OS and PFS were calculated using Kaplan-Meier methods. The log-rank test was used for statistical analysis, with values of p < 0.05 taken as significant. For PD-L1 immunohistochemistry assays, Dako 28-8 antibody was used.

RESULTS

In the all-patients group, median OS was 9.6 months and 1-year OS rate was 40.4%. Median PFS was 4.0 months and 1-year PFS rate was 37.8%. The cut-off value of PD-L1 expression for OS was 40% for all patients and the SCC group. When PD-L1 expression was ≥40%, OS was significantly better in both all patients and the SCC group (p = 0.004, 0.007). The cut-off value of PD-L1 expression for PFS was also 40%. When PD-L1 expression was ≥40%, PFS was better in all patients and the SCC group (P = 0.003, 0.009). In the all-patients group, ORR was 19.2% and disease control rate (DCR) was 44.2%. When PD-L1 expression was ≥40%, ORR was 44.4% and DCR 83.3%.

CONCLUSION

In the present study, when PD-L1 expression was high (≥40%), OS was significantly better (p = 0.004). This finding has not been reported in other research on R/M-HNC. PFS and ORR were also better with high PD-L1 expression. Regarding patterns of progression with a PD-L1 expression cut-off of 40%, hyperprogression was significantly more frequent for PD-L1 expression <40% (p = 0.039). Therefore, high PD-L1 expression could offer a predictor of prognosis and efficacy for nivolumab. The present findings may prove useful in considering treatment strategies.

Immune Checkpoint Inhibitors for Lung Cancer Treatment: A Review

The treatment of lung cancer has changed drastically in recent years owing to the advent of immune checkpoint inhibitors (ICIs). A 1992 study reported that programmed cell death-1 (PD-1), an immune checkpoint molecule, is upregulated during the induction of T cell death. Since then, various immunoregulatory mechanisms involving PD-1 have been clarified, and the successful use of PD-1 blockers in anticancer therapy eventually led to the development of the current generation of ICIs. Nivolumab was the first ICI approved for treating lung cancer in 2014. Since then, various ICIs such as pembrolizumab, atezolizumab, and durvalumab have been successively introduced into clinical medicine and have shown remarkable efficacy. The introduction of ICIs constituted a major advancement in lung cancer treatment, but disease prognosis continues to remain low. Therefore, new molecular-targeted therapies coupled with existing anticancer drugs and radiotherapy have recently been explored. This review encompasses the current status, challenges, and future perspectives of ICI treatment in lung cancer.

Viral Vector-Based Melanoma Gene Therapy

Gene therapy applications of oncolytic viruses represent an attractive alternative for cancer treatment. A broad range of oncolytic viruses, including adenoviruses, adeno-associated viruses, alphaviruses, herpes simplex viruses, retroviruses, lentiviruses, rhabdoviruses, reoviruses, measles virus, Newcastle disease virus, picornaviruses and poxviruses, have been used in diverse preclinical and clinical studies for the treatment of various diseases, including colon, head-and-neck, prostate and breast cancer as well as squamous cell carcinoma and glioma. The majority of studies have focused on immunotherapy and several drugs based on viral vectors have been approved. However, gene therapy for malignant melanoma based on viral vectors has not been utilized to its full potential yet. This review represents a summary of the achievements of preclinical and clinical studies using viral vectors, with the focus on malignant melanoma.

Regulation of Fas in response to bortezomib and epirubicin in colorectal cancer cells

Bortezomib is a reversible proteasome inhibitor affects the ubiquitin-proteasome mechanism to kill cancer cells, and inhibition of the proteasome modulates the expression of multiple target genes at the transcriptional level. Epirubicin is known as an anthracycline agent that interferes with DNA and RNA synthesis, and it can be used with other chemotherapeutic drugs in the treatment of post-surgical breast cancer. Epirubicin may have an anti-tumor effect against broad-spectrum tumor cells. However, it is a non-specific chemotherapeutic agent that can cause high toxicity if not used in appropriate doses. Here, we hypothesize that a combination treatment of bortezomib and epirubicin will induce immunogenic cell death in colorectal cancer cells by increasing expression of death receptors such as Fas, which will make these cancer cells more susceptible to Fas/FasL mediated tumor cell killing. Our data demonstrate that a combination of bortezomib and epirubicin significantly increases the sensitivity of colorectal carcinoma cells, but not healthy non-malignant epithelial cells, to apoptosis. The combination treatment significantly upregulates the transcriptional activation of Fas in colorectal cancer cells but not in normal cells. Our results suggest that combining bortezomib and epirubicin may simultaneously enhance tumor immunogenicity and the induction of antitumor immunity.

Anti-PD-1 antibody decreases tumour-infiltrating regulatory T cells

Background

There are many types of therapies for cancer. In these days, immunotherapies, especially immune checkpoint inhibitors, are focused on. Though many types of immune checkpoint inhibitors are there, the difference of effect and its mechanism are unclear. Some reports suggest the response rate of anti-PD-1 antibody is superior to that of anti-PD-L1 antibody and could potentially produce different mechanisms of action. On the other hand, Treg also express PD-1; however, their relationship remains unclear.

Methods

In this study, we used osteosarcoma cell lines in vitro and osteosarcoma mouse model in vivo. In vitro, we analyzed the effect of IFNγ for expression of PD-L1 on the surface of cell lines by flowcytometry. In vivo, murine osteosarcoma cell line LM8 was subcutaneously transplanted into the dorsum of mice. Mouse anti-PD-1 antibody was intraperitoneally administered. we analysed the effect for survival of anti-PD-1 antibody and proportion of T cells in the tumour by flowcytometry.

Results

We discovered that IFNγ increased PD-L1 expression on the surface of osteosarcoma cell lines. In assessing the relationship between anti-PD-1 antibody and Treg, we discovered the administration of anti-PD-1 antibody suppresses increases in tumour volume and prolongs overall survival time. In the tumour microenvironment, we found that the administration of anti-PD-1 antibody decreased Treg within the tumour and increased tumour-infiltrating lymphocytes.

Conclusions

Here we clarify for the first time an additional mechanism of anti-tumour effect—as exerted by anti-PD-1 antibody decreasing Treg— we anticipate that our findings will lead to the development of new methods for cancer treatment.

Ellagic acid, extracted from Sanguisorba officinalis, induces G1 arrest by modulating PTEN activity in B16F10 melanoma cells

In Chinese medicine, herbal medicine is commonly used to treat individuals suffering from many types of diseases. We thus expected that some herbal medicines would contain promising compounds for cancer chemotherapy. Indeed, we found that Sanguisorba officinalis extracts strongly inhibit the growth of B16F10 melanoma cells, and we identified ellagic acid (EA) as the responsible ingredient. B16F10 cells treated with EA exhibited strong G1 arrest accompanied by accumulation of p53, followed by inactivation of AKT. Addition of a PTEN inhibitor, but not a p53 inhibitor, abrogated the EA-induced AKT inactivation and G1 arrest. The PTEN inhibitor also diminished EA-induced p53 accumulation. Furthermore, EA apparently increased the protein phosphatase activity of PTEN, as demonstrated by the reduced phosphorylation level of FAK, a protein substrate of PTEN. Furthermore, an in vitro PTEN phosphatase assay on PIP3 showed the direct modulation of PTEN activity by EA. These results suggest that EA functions as an allosteric modulator of PTEN, enhancing its protein phosphatase activity while inhibiting its lipid phosphatase activity. It is notable that a combination of EA and cisplatin, a widely used chemotherapy agent, dramatically enhanced cell death in B16F10 cells, suggesting a promising strategy in chemotherapy.

Immune therapy of melanoma: Overview of therapeutic vaccines

Melanoma is the most serious type of skin cancer which develops from the occurrence of genetic mutations in the melanocytes. Based on the features of melanoma tumors such as location, genetic profile and stage, there are several therapeutic strategies including surgery, chemotherapy, and radiotherapy. However, because of the appearance resistance mechanisms, the efficiency of these treatments strategies may be reduced. It has been demonstrated that therapeutic monoclonal antibodies can improve the efficiency of melanoma therapies. Recently, several mAbs, such as nivolumab, pembrolizumab, and ipilimumab, were approved for the immunotherapy of melanoma. The antibodies inhibit immune checkpoint receptors such as CTL4 and pd-1. Another therapeutic strategy for the treatment of melanoma is cancer vaccines, which improve clinical outcomes in patients. The combination therapy using antibodies and gene vaccine give us a new perspective in the treatment of melanoma patients. Herein, we present the recent progressions in the melanoma immunotherapy, especially dendritic cells mRNA vaccines by reviewing recent literature.

GP. Nanoliposomal delivery of cytosolic phospholipase A2 inhibitor arachidonyl trimethyl ketone for melanoma treatment

Drug resistance and toxicity are major limitations of cancer treatment and frequently occurs during melanoma therapy. Nanotechnology can decrease drug resistance by improving drug delivery, with limited toxicity. This study details the development of nanoparticles containing arachidonyl trifluoromethyl ketone (ATK), a cytosolic phospholipase A₂ inhibitor, which can inhibit multiple key pathways responsible for the development of recurrent resistant disease. Free ATK is toxic, limiting its efficacy as a therapeutic agent. Hence, a novel nanoliposomal delivery system called NanoATK was developed, which loads 61.7% of the compound and was stable at 4^oC for 12 weeks. The formulation decreased toxicity-enabling administration of higher doses, which was more effective at inhibiting melanoma cell growth compared to free-ATK. Mechanistically, NanoATK decreased cellular proliferation and triggered apoptosis to inhibit melanoma xenograft tumor growth without affecting animal weight. Functionally, it inhibited the cPLA₂, AKT, and STAT3 pathways. Our results suggest the successful preclinical development of a unique nanoliposomal formulation containing ATK for the treatment of melanoma.

Cutaneous melanoma: From pathogenesis to therapy (Review)

In less than 10 years, melanoma treatment has been revolutionized with the approval of tyrosine kinase inhibitors and immune checkpoint inhibitors, which have been shown to have a significant impact on the prognosis of patients with melanoma. The early steps of this transformation have taken place in research laboratories. The mitogen‑activated protein kinase (MAPK) pathway, phosphoinositol‑3‑kinase (PI3K) pathway promote the development of melanoma through numerous genomic alterations on different components of these pathways. Moreover, melanoma cells deeply interact with the tumor microenvironment and the immune system. This knowledge has led to the identification of novel therapeutic targets and treatment strategies. In this review, the epidemiological features of cutaneous melanoma along with the biological mechanisms involved in its development and progression are summarized. The current state‑of‑the‑art of advanced stage melanoma treatment strategies and the currently available evidence of the use of predictive and prognostic biomarkers are also discussed.

BRAF and MEK Inhibitors Influence the Function of Reprogrammed T Cells: Consequences for Adoptive T-Cell Therapy

BRAF and MEK inhibitors (BRAFi/MEKi), the standard treatment for patients with BRAF^V600 mutated melanoma, are currently explored in combination with various immunotherapies, notably checkpoint inhibitors and adoptive transfer of receptor-transfected T cells. Since two BRAFi/MEKi combinations with similar efficacy are approved, potential differences in their effects on immune cells would enable a rational choice for triple therapies. Therefore, we characterized the influence of the clinically approved BRAFi/MEKi combinations dabrafenib (Dabra) and trametinib (Tram) vs. vemurafenib (Vem) and cobimetinib (Cobi) on the activation and functionality of chimeric antigen receptor (CAR)-transfected T cells. We co-cultured CAR-transfected CD8⁺ T cells and target cells with clinically relevant concentrations of the inhibitors and determined the antigen-induced cytokine secretion. All BRAFi/MEKi reduced this release as single agents, with Dabra having the mildest inhibitory effect, and Dabra + Tram having a clearly milder inhibitory effect than Vem + Cobi. A similar picture was observed for the upregulation of the activation markers CD25 and CD69 on CAR-transfected T cells after antigen-specific stimulation. Most importantly, the cytolytic capacity of the CAR-T cells was significantly inhibited by Cobi and Vem + Cobi, whereas the other kinase inhibitors showed no effect. Therefore, the combination Dabra + Tram would be more suitable for combining with T-cell-based immunotherapy than Vem + Cobi.

CD14+ HLA-DR-/low MDSCs are elevated in the periphery of early-stage breast cancer patients and suppress autologous T cell proliferation

PURPOSE

Despite the recent expansion in the use of immunotherapy for many cancer types, it is still not a standard treatment for breast cancer. Identifying differences in the immune systems of breast cancer patients compared to healthy women might provide insight into potential targets for immunotherapy and thus may assist its clinical implementation.

METHODS

Multi-colour flow cytometry was used to investigate myeloid and lymphoid populations in the peripheral blood of breast cancer patients (n = 40) and in the blood of healthy age-matched women (n = 25). We additionally performed functional testing to identify immune suppressive mechanisms used by circulating CD14+ myeloid cells from breast cancer patients.

RESULTS

Our results show that breast cancer patients have significantly elevated frequencies of cells with the monocytic myeloid-derived suppressor cell (mMDSC) phenotype CD14+ HLA-DR-/low compared with healthy women (p < 0.01). We also observed higher levels of earlier differentiated T cells and correspondingly lower levels of T cells in later stages of differentiation (p < 0.05). These disease-associated differences could already be detected in early-stage breast cancer patients in stages 1 and 2 (n = 33 of 40) (p < 0.05). Levels of circulating T cells correlated with certain clinical features and with patient age (p < 0.05). Functional tests showed that CD14+ myeloid cells from breast cancer patients more potently suppressed autologous T cell proliferation than CD14+ cells from healthy women (p < 0.01). Subsequent investigation determined that suppression was mediated in part by reactive oxygen species, because inhibiting this pathway partially restored T cell proliferation (p < 0.01).

CONCLUSION

Our results highlight the potential importance of cells with mMDSC phenotypes in breast cancer, identifiable already at early stages of disease. This may provide a basis for identifying possible new therapeutic targets to enhance anti-cancer immunity.

Targeting the cross-talk between Urokinase receptor and Formyl peptide receptor type 1 to prevent invasion and trans-endothelial migration of melanoma cells

BACKGROUND

Accumulating evidence demonstrates that the Urokinase Receptor (uPAR) regulates tumor cell migration through its assembly in composite regulatory units with transmembrane receptors, and uPAR_88-92 is the minimal sequence required to induce cell motility through the Formyl Peptide Receptor type 1 (FPR1). Both uPAR and FPR1 are involved in melanoma tumor progression, suggesting that they may be targeted for therapeutic purposes. In this study, the role of the uPAR-FPR1 cross-talk to sustain melanoma cell ability to invade extracellular matrix and cross endothelial barriers is investigated. Also, the possibility that inhibition of the uPAR mediated FPR1-dependent signaling may prevent matrix invasion and transendothelial migration of melanoma cells was investigated.

METHODS

Expression levels of uPAR and FPR1 were assessed by immunocytochemistry, Western Blot and qRT-PCR. Cell migration was investigated by Boyden chamber and wound-healing assays. Migration and invasion kinetics, trans-endothelial migration and proliferation of melanoma cells were monitored in real time using the xCELLigence technology. The agonist-triggered FPR1 internalization was visualized by confocal microscope. Cell adhesion to endothelium was determined by fluorometer measurement of cell-associated fluorescence or identified on multiple z-series by laser confocal microscopy. The 3D-organotypic models were set up by seeding melanoma cells onto collagen I matrices embedded dermal fibroblasts. Data were analyzed by one-way ANOVA and post-hoc Dunnett t-test for multiple comparisons.

RESULTS

We found that the co-expression of uPAR and FPR1 confers to A375 and M14 melanoma cells a clear-cut capability to move towards chemotactic gradients, to cross extracellular matrix and endothelial monolayers. FPR1 activity is required, as cell migration and invasion were abrogated by receptor desensitization. Finally, melanoma cell ability to move toward chemotactic gradients, invade matrigel or fibroblast-embedded collagen matrices and cross endothelial monolayers are prevented by anti-uPAR_84-95 antibodies or by the RI-3 peptide which we have previously shown to inhibit the uPAR_84-95/FPR1 interaction.

CONCLUSIONS

Collectively, our findings identify uPAR and FPR1 as relevant effectors of melanoma cell invasiveness and suggest that inhibitors of the uPAR_84-95/FPR1 cross-talk may be useful for the treatment of metastatic melanoma.

NAADP-Dependent Ca(2+) Signaling Controls Melanoma Progression, Metastatic Dissemination and Neoangiogenesis

A novel transduction pathway for the powerful angiogenic factor VEGF has been recently shown in endothelial cells to operate through NAADP-controlled intracellular release of Ca²⁺. In the present report the possible involvement of NAADP-controlled Ca²⁺ signaling in tumor vascularization, growth and metastatic dissemination was investigated in a murine model of VEGF-secreting melanoma. Mice implanted with B16 melanoma cells were treated with NAADP inhibitor Ned-19 every second day for 4 weeks and tumor growth, vascularization and metastatization were evaluated. Control specimens developed well vascularized tumors and lung metastases, whereas in Ned-19-treated mice tumor growth and vascularization as well as lung metastases were strongly inhibited. In vitro experiments showed that Ned-19 treatment controls the growth of B16 cells in vitro, their migratory ability, adhesive properties and VEGFR2 expression, indicating NAADP involvement in intercellular autocrine signaling. To this regard, Ca²⁺ imaging experiments showed that the response of B16 cells to VEGF stimulation is NAADP-dependent. The whole of these observations indicate that NAADP-controlled Ca²⁺ signaling can be relevant not only for neoangiogenesis but also for direct control of tumor cells.

Prognostic impact of circulating Her-2-reactive T-cells producing pro- and/or anti-inflammatory cytokines in elderly breast cancer patients

Background

Treating elderly breast cancer patients remains a challenge but the increasing availability of immunotherapeutic approaches instills optimism that these tumours may also be susceptible to immune control. Because aging leads to a number of alterations in the immune system (“immunosenescence”) reflecting potential exhaustion which could compromise immunomodulatory antibody therapy, here we have assessed the immunocompetence of elderly breast cancer patients compared with a group of younger patients, and related this to the 5-year survival of the former.

Methods

T-cell responses to Her-2 peptide pools in vitro were assessed by analyzing pro- and anti-inflammatory cytokine production by CD4+ and CD8+ T-cells in 40 elderly and 35 younger breast cancer patients.

Results

The proportions of older and younger patients whose peripheral T-cells responded to Her-2 peptides in vitro were found to be similar, although a significantly higher fraction of younger patients possessed IL-2-producing CD4+ Her-2-reactive T-cells than in the elderly (p = 0.03). However, IL-2 production did not impart a survival benefit to the latter. In contrast, there was a survival benefit of possessing Her-2-reactive CD8+ T-cells, but this was abrogated in patients if they also had CD4+ Her-2-responsive T-cells that producedIL-5 and/or IL-17 (p = 0.01). This resulted in a 5-yr survival rate of only 29 % compared to 76 % for patients whose her-2-reactive CD4+ T-cells did not produceIL-5 and/or IL-17. Additionally, patients whose CD8+ T-cells produced TNF had a significantly better survival than those that did not (93 % compared to 52 %, p = 0.01), whereas no survival benefit was attributable to possessing IFN-γ-producing cells.

Conclusions

Elderly breast cancer patients appear perfectly immunocompetent to respond to Her-2 peptide pools in vitro, with response patterns very similar to younger patients. The nature of this response is associated with 5-year survival of these elderly patients, suggesting that boosting anti-tumor responses and modulating the nature of the T-cell response is likely to be effective even in potentially immunosenescent elderly breast cancer patients, and might be useful for predicting which patients are most likely to benefit from such treatments.

Electronic supplementary material

The online version of this article (doi:10.1186/s40425-015-0090-0) contains supplementary material, which is available to authorized users.

Presence of circulating Her2-reactive CD8 + T-cells is associated with lower frequencies of myeloid-derived suppressor cells and regulatory T cells, and better survival in older breast cancer patients

Introduction

Breast cancer is one of the most common cancers among women. Its incidence is increasing in many countries and a higher number of older women are now being diagnosed with the disease. Immune parameters are implicated in disease progression, and the frequencies of both myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs), associated with tumour burden, have been suggested to be indicators of poor prognosis in cases of metastatic breast cancer.

Methods

Here, we have assessed the frequency of peripheral Tregs and MDSCs in relation to in vitro T cell responses to Her2 antigen in 40 untreated breast cancer patients 65 to 87 years of age at diagnosis.

Results

The five-year survival rate of patients who mounted a CD8+ T cell response to Her2 peptides and had a lower frequency of Lin⁻CD14⁺HLA-DR⁻MDSCs was 100% compared to only 38% in patients without Her2-reactive CD8+ T cells and with higher frequencies of MDSCs (P = 0.03). Patients who lacked a CD8 response to Her2 tended to have higher frequencies of MDSCs. Similarly, patients who lacked a CD8 response to Her2 and had higher frequencies of CD4⁺Foxp3⁺CD127^lowCD25⁺ Tregs had only 50% survival compared to the 100% survival of patients who did mount a CD8 response and had lower frequencies of Tregs (P = 0.03). A similar trend was observed for activated (CD4⁺CD45RA⁻Foxp3^hi) but not resting Tregs (CD4⁺CD45RA⁺FoxP3⁺). This survival advantage was observed in both metastatic and non-metastatic patients.

Conclusions

Our data demonstrate a negative role of both MDSCs and Tregs in the prognosis of breast cancer patients, the mechanism of which might be through dampening favourable CD8+ T cell immune responses to tumour-associated antigens.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-015-0541-z) contains supplementary material, which is available to authorized users.

Evaluating biomarkers in melanoma

The incidence of cutaneous melanoma has more than doubled over the last decades making it one of the fastest rising cancers worldwide. Improved awareness and early detection of malignant moles now permit earlier diagnosis aiming to decrease the likelihood of recurrence. However, it is difficult to identify those patients initially diagnosed with localized melanoma who subsequently develop metastatic disease. For this group, prognosis remains poor and clinical outcomes are variable and challenging to predict. Considerable efforts have focused on the search for novel prognostic tools, with numerous markers evaluated in the circulation and in tumor lesions. The most reliable predictors of patient outcome are the clinical and histological features of the primary tumor such as Breslow thickness, ulceration status, and mitotic rate. Elevated serum levels of the enzyme lactate dehydrogenase, likely to indicate active metastatic disease, are also routinely used to monitor patients. The emergence of novel immune and checkpoint antibody treatments for melanoma and increasing appreciation of key roles of the immune system in promoting or halting cancer progression have focused attention to immunological biomarkers. Validation of the most promising of these may have clinical applications in assisting prognosis, assessing endpoints in therapy, and monitoring responses during treatment.

Immune checkpoint inhibitors in clinical trials

Immunology-based therapy is rapidly developing into an effective treatment option for a surprising range of cancers. We have learned over the last decade that powerful immunologic effector cells may be blocked by inhibitory regulatory pathways controlled by specific molecules often called "immune checkpoints." These checkpoints serve to control or turn off the immune response when it is no longer needed to prevent tissue injury and autoimmunity. Cancer cells have learned or evolved to use these mechanisms to evade immune control and elimination. The development of a new therapeutic class of drugs that inhibit these inhibitory pathways has recently emerged as a potent strategy in oncology. Three sets of agents have emerged in clinical trials exploiting this strategy. These agents are antibody-based therapies targeting cytotoxic T-lymphocyte antigen 4 (CTLA4), programmed cell death 1 (PD-1), and programmed cell death ligand 1 (PD-L1). These inhibitors of immune inhibition have demonstrated extensive activity as single agents and in combinations. Clinical responses have been seen in melanoma, renal cell carcinoma, non-small cell lung cancer, and several other tumor types. Despite the autoimmune or inflammatory immune-mediated adverse effects which have been seen, the responses and overall survival benefits exhibited thus far warrant further clinical development.