Metastatic Melanoma: Recent Therapeutic Progress and Future Perspectives

Treatment of Recurrent Melanoma Following Adjuvant Therapy

In the era of effective therapies in melanoma, notably the widespread use of two types of adjuvant treatments: anti-PD-1 immunotherapies and therapies targeting the mitogen-activated protein kinase pathway, for BRAF-mutant patients, an important question arises about how to treat these patients in case of recurrent melanoma following adjuvant therapy. Prospective data are lacking in this area and might be difficult to obtain due to the constant progress being made in the field. Therefore, we reviewed available data suggesting that the initial adjuvant treatment received and the following events provide information about the biology of the disease and the probability of response to following systemic treatments. Thus, in case of relapse during or just after adjuvant anti-PD-1, immune resistance is probable, an anti-PD-1 monotherapy rechallenge has a low likelihood of clinical benefit, and escalation with a combination of immunotherapies should be given priority. In case of relapse during treatment with BRAF plus MEK inhibitors, there may be a risk of lower efficacy of immunotherapy than in naïve patients since this relapse attests not only to a resistance to BRAF-MEK inhibition, but also the introduction of immunotherapy to rescue a progression on targeted therapy. In case of relapse long after adjuvant treatment cessation, whatever the treatment received, no conclusion can be drawn about the efficacy of these drugs, and these patients can be treated like naïve patients. Thus, a combination of anti-PD-1 and anti-CTLA4 is probably the best solution, and the following line can be BRAF-MEK inhibitors in BRAF-mutated patients. Finally, in case of recurrent melanoma following adjuvant therapy, given the promising upcoming strategies, inclusion in a clinical trial should be offered as frequently as possible.

Cost-effectiveness of immune checkpoint inhibition and targeted treatment in combination as adjuvant treatment of patient with BRAF-mutant advanced melanoma

BACKGROUND

Immune checkpoint inhibitors (ICIs) and targeted treatments have improved the health outcomes of patients with advanced melanoma. However, due to the high cost of novel therapies, it is crucial to evaluate their value by considering both effectiveness and cost. To compare the cost-effectiveness of these novel agents (atezolizumab-vemurafenib-cobimetinib, vemurafenib-plus-cobimetinib, dabrafenib-plus-trametinib, and encorafenib-plus-binimetinib) for first-line treatment of metastatic melanoma with the BRAF^V600 mutation.

METHODS

A patient-level model was developed to project the health outcomes of 4 strategies for patients with advanced melanoma. We estimated transition probabilities from the IMspire150 (ClinicalTrials.gov, NCT02908672), COMBI-AD (NCT01682083), and COLUMBUS (NCT01909453) trials using a parametric survival model. All health outcomes, including direct cost, quality-adjusted life-years (QALYs) and the incremental cost-effectiveness ratio (ICER), were estimated from the US payer perspective. Lifetime cost, QALYs, life-years (LYs), and ICERs were calculated. Univariable and probabilistic sensitivity analyses were performed to test model robustness, along with multiple scenario analyses.

RESULTS

Of the 4 competing strategies, atezolizumab-vemurafenib-cobimetinib produced the best health outcomes, and the vemurafenib-cobimetinib strategy was the least expensive option. Atezolizumab-vemurafenib-cobimetinib, dabrafenib-plus-trametinib, and vemurafenib-cobimetinib formed the cost-effective frontier, indicating that the ordered ICERs were $325,113/QALYs for dabrafenib-plus-trametinib vs. vemurafenib-cobimetinib strategies and $2,247,500/QALYs for atezolizumab-vemurafenib-cobimetinib vs. dabrafenib-plus-trametinib strategies. Encorafenib-plus-binimetinib was dominated by the other 3 competing strategies. The drug price and first-line utility significantly influenced the model utcomes.

CONCLUSIONS

For BRAF-mutant advanced melanoma, the vemurafenib-cobimetinib strategy could be considered the most cost-effective treatment at the willingness-to-pay threshold of $150,000.

Momordica cochinchinensis (Gấc) Seed Extracts Induce Apoptosis and Necrosis in Melanoma Cells

Momordica cochinchinensis is a herbal medicine used throughout Asia and this study investigated the antimelanoma potentials and molecular mechanisms of M. cochinchinensis seed with emphasis on extraction to optimise bioactivity. Overall, the aqueous extract was superior, with a wider diversity and higher concentration of proteins and peptides that was more cytotoxic to the melanoma cells than other extraction solvents. The IC50 of the aqueous extract on melanoma cells were similar to treatment with current anticancer drugs, vemurafenib and cisplatin. This cytotoxicity was cancer-specific with lower cytotoxic effects on HaCaT epidermal keratinocytes. Cytotoxicity correlated with MAPK signalling pathways leading to apoptosis and necrosis induced by triggering tumour necrosis factor receptor-1 (TNFR1), reducing the expression of nuclear factor kappa B (NF-kB), and suppression of BRAF/MEK. This efficacy of M. cochinchinensis seed extracts on melanoma cells provides a platform for future clinical trials as potent adjunctive therapy for metastatic melanoma.

Current studies and future promises of PD-1 signal inhibitors in cervical cancer therapy

PD-1 (Programmed cell death-1) is a receptor that inhibits the activation of T cells and is an important target for cancer immunotherapy. PD-1 expression stays high on antigen-specific T cells that have been stimulated for a long time, making them less responsive to stimuli. Consequently, there has been a recent surge in the number of researchers focusing on how the PD-1 axis delivers inhibitory signals to uncover new therapeutic targets. As an inhibitory signaling mechanism, the PD-1 axis controls immunological responses. Blocking the PD-1 axis has been shown to have long-lasting effects on various cancers, demonstrating the crucial role of PD-1 in blocking anti-tumor immunity. Despite this role, most patients do not respond to PD-1 monotherapy, and some have experienced adverse events. Many challenges remain regarding the PD-1 signaling axis to be addressed. In this review, we outline the most recent research and prospects of PD-1 signal inhibitors to enhance cervical cancer therapy.

Quality by Design steered Development of Niclosamide Loaded Liposomal Thermogel for Melanoma: In vitro and Ex vivo Evaluation

Melanoma is the most malignant form of skin cancer across the globe. Conventional therapies are currently ineffective which could be attributed to the rampant chemo-resistance, metastasis, inability to cross the skin barriers and accumulate within the tumor microenvironment. This advent brings in the principles of drug repurposing by repositioning Niclosamide (NIC), an anthelmintic drug for skin cancer. Incorporation into the liposomes facilitated enhanced melanoma cell uptake and apoptosis. Cytotoxicity studies revealed 1.756-fold enhancement in SK-MEL-28 cytotoxicity by NIC-loaded liposomes compared to free drug. Qualitative and quantitative cell internalization indicated greater drug uptake within the melanoma cells illustrating the efficacy of liposomes as efficient carrier systems. Nuclear staining showed blebbing and membrane shrinkage. Elevated ROS levels and apoptosis shown by DCFDA and acridine orange-ethidium bromide staining revealed greater melanoma cell death by liposomes compared to free drug. Incorporating NIC liposomes into the thermogel system restricted the liposomes as a depot onto the upper skin layers. Sustained zero order release up to 48 h with liposomes and 23.58-fold increase in viscosity led to the sol-to-gel transition at 33℃ was observed with liposomal thermogel. Ex vivo gel permeation studies revealed that C-6 loaded liposomes incorporated within the thermogel successfully formed a depot over the upper skin layer for 6 h to prevent transdermal delivery and systemic adverse effects. Thus, it could be concluded that NIC loaded liposomal thermogel system could be an efficacious therapeutic alternative for the management of melanoma.

Photosensitizer-loaded gold nanocages for immunogenic phototherapy of aggressive melanoma

Malignant melanoma remains the life-threatening form of skin cancer with high mortality and poor prognosis. Thus, an ideal melanoma therapeutic strategy is of immediate importance which can remove the primary tumor, as well as inhibit the metastasis and recurrence. Here, we report the fabrication of adjuvant monophosphoryl lipid A (MPLA) lipid bilayer-enveloped and photosensitizer indocyanine green (ICG)-loaded gold nanocages (MLI-AuNCs) for immunogenic phototherapy of aggressive melanoma. Hollow porous AuNCs are used as carriers to deliver MPLA and ICG, and protect ICG from photodegradation. Both AuNCs and ICG absorb near infrared (NIR) light and can be applied in controllable NIR-triggered photothermal and photodynamic combination therapy (PTT/PDT) of melanoma. MLI-AuNCs coated by thermosensitive lipid bilayer exhibit uniform size, good biocompatibility and bioavailability with prominent tumor accumulation, which further improve the PTT/PDT efficacy. MLI-AuNCs under NIR irradiation not only destroy the primary tumor by PTT/PDT, but also elicit robust antitumor immune response with melanoma associated antigens and MPLA released in situ. The released antigens and MPLA subsequently enhance the recruitment and maturation of dendritic cells, which further activate the effector T cells to inhibit metastases and recurrence of melanoma. This immunomodulatory-boosted PTT/PDT nanoplatform provides a new opportunity for highly aggressive melanoma treatment. STATEMENT OF SIGNIFICANCE: An ideal tumor therapeutic strategy not only can remove the primary tumor, but also inhibit metastasis and recurrence. Here, we introduced a versatile nanoplatform MLI-AuNCs for immunogenic phototherapy of aggressive melanoma. Adjuvant MPLA and photosensitizer ICG can be protected and co-delivered to the tumors by thermosensitive lipid-enveloped AuNCs. MLI-AuNCs exhibited prominent tumor accumulation ability and produced the potent PTT/PDT effect to destroy the primary tumors with a single dose of NIR irradiation, as well as elicited the strong antitumor immunity to inhibit the metastasis and relapse. This study may provide a potential therapeutic vaccination strategy against advanced melanoma and other difficult-to-treat cancers.

Apoptosis Pathways Triggered by a Potent Antiproliferative Hybrid Chalcone on Human Melanoma Cells

The World Health Organization reported that approximately 324,000 new cases of melanoma skin cancer were diagnosed worldwide in 2020. The incidence of melanoma has been increasing over the past decades. Targeting apoptotic pathways is a potential therapeutic strategy in the transition to preclinical models and clinical trials. Some naturally occurring products and synthetic derivatives are apoptosis inducers and may represent a realistic option in the fight against the disease. Thus, chalcones have received considerable attention due to their potential cytotoxicity against cancer cells. We have previously reported a chalcone containing an indole and a pyridine heterocyclic rings and an α-bromoacryloylamido radical which displays potent antiproliferative activity against several tumor cell lines. In this study, we report that this chalcone is a potent apoptotic inducer for human melanoma cell lines SK-MEL-1 and MEL-HO. Cell death was associated with mitochondrial cytochrome c release and poly(ADP-ribose) polymerase cleavage and was prevented by a non-specific caspase inhibitor. Using SK-MEL-1 as a model, we found that the mechanism of cell death involves (i) the generation of reactive oxygen species, (ii) activation of the extrinsic and intrinsic apoptotic and mitogen-activated protein kinase pathways, (iii) upregulation of TRAIL, DR4 and DR5, (iv) downregulation of p21^Cip1/WAF1 and, inhibition of the NF-κB pathway.

Pathogenic roles of long noncoding RNAs in melanoma: Implications in diagnosis and therapies

Melanoma is one of the most dangerous types of cutaneous neoplasms, which are pigment-producing cells of neuroectodermal origin found all over the body. A great deal of research is focused on the mechanisms of melanoma to promote better diagnostic and treatment options for melanoma in its advanced stages. The progression of melanoma involves alteration in different levels of gene expression. With the successful implementation of next-generation sequencing technology, an increasing number of long noncoding RNAs (lncRNAs) sequences have been discovered, and a significant number of them have phenotypic effects in both in vitro and in vivo studies, implying that they play an important role in the occurrence and progression of human cancers, particularly melanoma. A number of evidence indicated that lncRNAs are important regulators in tumor cell proliferation, invasion, apoptosis, immune escape, energy metabolism, drug resistance, epigenetic regulation. To better understand the role of lncRNAs in melanoma tumorigenesis, we categorize melanoma-associated lncRNAs according to their cellular functions and associations with gene expression and signaling pathways in this review. Based on the mechanisms of lncRNA, we discuss the possibility of lncRNA-target treatments, and the application of liquid biopsies to detect lncRNAs in melanoma diagnosis and prognosis.

Effect of L- to D-Amino Acid Substitution on Stability and Activity of Antitumor Peptide RDP215 against Human Melanoma and Glioblastoma

The study investigates the antitumor effect of two cationic peptides, R-DIM-P-LF11-215 (RDP215) and the D-amino acid variant 9D-R-DIM-P-LF11-215 (9D-RDP215), targeting the negatively charged lipid phosphatidylserine (PS) exposed by cancer cells, such as of melanoma and glioblastoma. Model studies mimicking cancer and non-cancer membranes revealed the specificity for the cancer-mimic PS by both peptides with a slightly stronger impact by the D-peptide. Accordingly, membrane effects studied by DSC, leakage and quenching experiments were solely induced by the peptides when the cancer mimic PS was present. Circular dichroism revealed a sole increase in β-sheet conformation in the presence of the cancer mimic for both peptides; only 9D-RDP215 showed increased structure already in the buffer. Ex vitro stability studies by SDS-PAGE as well as in vitro with melanoma A375 revealed a stabilizing effect of D-amino acids in the presence of serum, which was also confirmed in 2D and 3D in vitro experiments on glioblastoma LN-229. 9D-RDP215 was additionally able to pass a BBB model, whereupon it induced significant levels of cell death in LN-229 spheroids. Summarized, the study encourages the introduction of D-amino acids in the design of antitumor peptides for the improvement of their stable antitumor activity.

Evaluation of 2-methoxyestradiol serum levels as a potential prognostic marker in malignant melanoma

Experimental findings indicated that 2-methoxyestradiol (2-ME), an endogenous metabolite of 17β-estradiol, may exhibit anti-tumorigenic properties in various types of tumour, such as melanoma and endometrial carcinoma. In patients with endometrial cancer, the serum levels of 2-ME are decreased compared with those in healthy controls, and this finding has been associated with a poor outcome. The aim of the present study was to examine whether the serum levels of 2-ME are decreased in patients with melanoma, and whether this decrease may be correlated with disease stage and, therefore, serve as a prognostic indicator. ELISA was used to detect serum levels of 2-ME in patients with stage I-IV malignant melanoma (MM). A cohort of 78 patients with MM was analysed, along with 25 healthy controls, among whom 15 were women in the second trimester of pregnancy (positive control). As expected, significantly elevated levels of serum 2-ME were observed in pregnant control patients compared with those in patients with MM and healthy controls. There was no observed correlation between 2-ME serum levels in patients with MM and disease stage, tumour thickness, lactate dehydrogenase or S100 calcium-binding protein B levels. In addition, the 2-ME levels of patients with MM did not differ significantly from those of normal healthy controls. Overall, the findings of the present study indicated that the 2-ME serum levels in patients with MM were not decreased, and there was no correlation with early- or advanced-stage disease. Therefore, in contrast to published results on endometrial cancer, endogenous serum 2-ME levels in MM were not found to be correlated with tumour stage and did not appear to be a suitable prognostic factor in MM.

Survival of advanced melanoma patients treated with immunotherapy and targeted therapy: A real-world study

INTRODUCTION

We aimed to examine the survival outcomes plus patient and treatment characteristics of advanced melanoma patients treated with first-line immunotherapy (IT), targeted therapy (TT), and chemotherapy (CTH) and compare findings with information from pivotal trials for each therapy.

MATERIALS AND METHODS

We retrospectively reviewed the use of systematic IT, TT and CTH therapies in melanoma patients in four Queensland public hospitals. We estimated median duration of overall survival (OS) and survival rates (6 months, 1, and 2 years) using Kaplan-Meier methods. We compared our findings to those of clinical trials.

RESULTS

Five hundred three patients who met the inclusion criteria were divided into three groups based on the first-line treatment: IT 232; TT 157; and CTH 114. OS was 18 months with IT (95% CI 13, 22); 12 months with TT (95% CI 8, 15); and 5 months with CTH (95% CI 5, 6). The demographic characteristics, treatment protocols, and durations for IT and TT were generally consistent with trials but fewer patients in our study had subsequent therapy than in the trials. The OS in our study was slightly lower than the OS reported in trials.

CONCLUSION

The OS of novel cancer therapy in the real world was lower than seen in trials but is expected given these are patients who have a poorer prognosis. A future study could investigate the impact of prognostic factors on survival in the longer term. This study provides evidence that we can use routinely collected real-world data to evaluate the effectiveness of checkpoint and kinase inhibitors in patients with advanced melanoma.

Organ transplantation and outcomes in patients with a past history of melanoma: A systematic review and meta-analysis

BACKGROUND

The incidence of melanoma is steadily rising around the world. There is uncertainty about the safety of solid organ transplantation in patients with a prior history of melanoma.

AIM

To review studies reporting patients with a history of melanoma before solid organ transplantation.

METHODS

Electronic searches of Medline, Embase, and the Cochrane library up to March 2020. All study designs, in any language and without sample size restriction, were eligible for inclusion. Risk of bias was assessed using established tools, and meta-analysis was performed using a random-effects model.

RESULTS

We identified 41 studies reporting 703 100 transplant recipients and 1692 had pre-transplantation melanomas. Risk of death, expressed as a hazard ratio, in patients with pre-transplantation melanoma relative to those without prior melanoma, was 1.32 (95% CI: 1.09-1.59). After transplantation, 13.1% of patients with pre-transplantation melanoma developed new or recurrent melanoma (IQR: 4.8%-18.2%).

CONCLUSIONS

Around 1-in-400 transplant recipients had a prior history of melanoma. This was associated with a greater than 1-in-10 risk of new or recurrent melanoma after transplantation and an increased risk of death. A 5-year waiting time between a melanoma diagnosis and transplantation has been recommended based on historic registry data, but very little additional information is available to justify or revise this.

Small Molecules in the Treatment of Squamous Cell Carcinomas: Focus on Indirubins

Simple Summary

In this review, the genetic landscape of squamous cell carcinoma is related to the potential targets of indirubin-based small molecules in cancer therapy. Being a component of traditional Chinese medicine, indirubins are used to treat chronic or inflammatory diseases, and have received increasing attention in cancer treatment due to their proapoptotic and antiproliferative activity. Frequent genetic alterations of squamous cell carcinomas are summarized, and it is discussed how these may render tumors susceptible to indirubin-based small molecule inhibitors.

Abstract

Skin cancers are the most common malignancies in the world. Among the most frequent skin cancer entities, squamous cell carcinoma (SCC) ranks second (~20%) after basal cell carcinoma (~77%). In early stages, a complete surgical removal of the affected tissue is carried out as standard therapy. To treat advanced and metastatic cancers, targeted therapies with small molecule inhibitors are gaining increasing attention. Small molecules are a heterogeneous group of protein regulators, which are produced by chemical synthesis or fermentation. The majority of them belong to the group of receptor tyrosine kinase inhibitors (RTKIs), which specifically bind to certain RTKs and directly influence the respective signaling pathway. Knowledge of characteristic molecular alterations in certain cancer entities, such as SCC, can help identify tumor-specific substances for targeted therapies. Most frequently, altered genes in SCC include TP53, NOTCH, EGFR, and CCND1. For example, the gene CCND1, which codes for cyclin D1 protein, is upregulated in nearly half of SCC cases and promotes proliferation of affected cells. A treatment with the small molecule 5′-nitroindirubin-monoxime (INO) leads to inhibition of cyclin D1 and thus inhibition of proliferation. As a component of Danggui Longhui Wan, a traditional Chinese medicine, indirubins are used to treat chronic diseases and have been shown to inhibit inflammatory reactions. Indirubins are pharmacologically relevant small molecules with proapoptotic and antiproliferative activity. In this review, we discuss the current literature on indirubin-based small molecules in cancer treatment. A special focus is on the molecular biology of squamous cell carcinomas, their alterations, and how these are rendered susceptible to indirubin-based small molecule inhibitors. The potential molecular mechanisms of the efficacy of indirubins in killing SCC cells will be discussed as well.

Silencing Osteopontin Expression Inhibits Proliferation, Invasion and Induce Altered Protein Expression in Melanoma Cells

Osteopontin (OPN) is a multifunctional phosphoprotein that is expressed in different types of cancers, including melanoma. OPN overexpression is associated with tumor progression and metastasis formation; however, the role of OPN in cell invasion and metastasis formation is not completely understood. In this study we aimed to define OPN expression in melanoma tissues and cell lines and investigate the effect of OPN expression on cell proliferation and invasion after inhibiting OPN expression with small interfering RNA (siRNA). OPN gene expression was determined by qRT-PCR, while protein expression was examined using a Proteome Profiler Oncology Array. siRNA-mediated OPN knockdown led to decreased OPN expression in melanoma cell lines, which was associated with decreased cell proliferation and invasion. Proteome profile analysis revealed significantly different protein expression between the original and transfected cell lines. The altered expression of the differently expressed proteins was validated at the mRNA level. Furthermore, OPN-specific siRNA was able to reduce OPN expression and inhibit the invasiveness of melanoma cells. Our results revealed for the first time that silencing the OPN gene influences proliferation and invasion of melanoma cells by effecting EGFR, tenascin C, survivin, galectin-3 and enolase 2 expression. To predict protein-protein interactions along with putative pathways we used STRING analysis for the differentially expressed proteins. These proteins formed multiple clusters, including extracellular matrix organization, regulation of angiogenesis, cell death and cell migration, PI3K-Akt, MAPK and focal adhesion signaling pathways. Taken together these data suggest that OPN might be an ideal target for drug development and therapies.

Nicotinamide inhibits melanoma in vitro and in vivo

Background

Even though new therapies are available against melanoma, novel approaches are needed to overcome resistance and high-toxicity issues. In the present study the anti-melanoma activity of Nicotinamide (NAM), the amide form of Niacin, was assessed in vitro and in vivo.

Methods

Human (A375, SK-MEL-28) and mouse (B16-F10) melanoma cell lines were used for in vitro investigations. Viability, cell-death, cell-cycle distribution, apoptosis, Nicotinamide Adenine Dinucleotide⁺ (NAD⁺), Adenosine Triphosphate (ATP), and Reactive Oxygen Species (ROS) levels were measured after NAM treatment. NAM anti-SIRT2 activity was tested in vitro; SIRT2 expression level was investigated by in silico transcriptomic analyses. Melanoma growth in vivo was measured in thirty-five C57BL/6 mice injected subcutaneously with B16-F10 melanoma cells and treated intraperitoneally with NAM. Interferon (IFN)-γ-secreting murine cells were counted with ELISPOT assay. Cytokine/chemokine plasmatic levels were measured by xMAP technology. Niacin receptors expression in human melanoma samples was also investigated by in silico transcriptomic analyses.

Results

NAM reduced up to 90% melanoma cell number and induced: i) accumulation in G1-phase (40% increase), ii) reduction in S- and G2-phase (about 50% decrease), iii) a 10-fold increase of cell-death and 2.5-fold increase of apoptosis in sub-G1 phase, iv) a significant increase of NAD⁺, ATP, and ROS levels, v) a strong inhibition of SIRT2 activity in vitro. NAM significantly delayed tumor growth in vivo (p ≤ 0.0005) and improved survival of melanoma-bearing mice (p ≤ 0.0001). About 3-fold increase (p ≤ 0.05) of Interferon-gamma (IFN-γ) producing cells was observed in NAM treated mice. The plasmatic expression levels of 6 cytokines (namely: Interleukin 5 (IL-5), Eotaxin, Interleukin 12 (p40) (IL12(p40)), Interleukin 3 (IL-3), Interleukin 10 (IL-10) and Regulated on Activation Normal T Expressed and Secreted (RANTES) were significantly changed in the blood of NAM treated mice, suggesting a key role of the immune response. The observed inhibitory effect of NAM on SIRT2 enzymatic activity confirmed previous evidence; we show here that SIRT2 expression is significantly increased in melanoma and inversely related to melanoma-patients survival. Finally, we show for the first time that the expression levels of Niacin receptors HCAR2 and HCAR3 is almost abolished in human melanoma samples.

Conclusion

NAM shows a relevant anti-melanoma activity in vitro and in vivo and is a suitable candidate for further clinical investigations.

CRISPR/Cas9-mediated Knockout of SIRT6 Imparts Remarkable Antiproliferative Response in Human Melanoma Cells in vitro and in vivo

Melanoma is one of the most aggressive, potentially fatal forms of skin cancer and has been shown to be associated with solar ultraviolet radiation-dependent initiation and progression. Despite remarkable recent advances with targeted and immune therapeutics, lasting and recurrence-free survival remain significant concerns. Therefore, additional novel mechanism-based approaches are needed for effective melanoma management. The sirtuin SIRT6 appears to have a pro-proliferative function in melanocytic cells. In this study, we determined the effects of genetic manipulation of SIRT6 in human melanoma cells, in vitro and in vivo. Our data demonstrated that CRISPR/Cas9-mediated knockout (KO) of SIRT6 in A375 melanoma cells resulted in a significant (1) decrease in growth, viability and clonogenic survival and (2) induction of G1-phase cell cycle arrest. Further, employing a RT² Profiler PCR array containing 84 key transformation and tumorigenesis genes, we found that SIRT6 KO resulted in modulation of genes involved in angiogenesis, apoptosis, cellular senescence, epithelial-to-mesenchymal transition, hypoxia signaling and telomere maintenance. Finally, we found significantly decreased tumorigenicity of SIRT6 KO A375 cells in athymic nude mice. Our data provide strong evidence that SIRT6 promotes melanoma cell survival, both in vitro and in vivo, and could be exploited as a target for melanoma management.

The Targeted Therapies Era Beyond the Surgical Point of View: What Spine Surgeons Should Know Before Approaching Spinal Metastases

In the last few years, the treatment of spinal metastases has significantly changed. This is due to the advancements in surgical technique, radiotherapy, and chemotherapy which have enriched the multidisciplinary management. Above all, the field of molecular biology of tumors is in continuous and prosperous evolution. In this review, the molecular markers and new approaches that have radically modified the chemotherapeutic strategy of the most common metastatic neoplasms will be examined together with clinical and surgical implications. The experience and skills of several different medical professionals are mandatory: an interdisciplinary oncology team represents the winning strategy in the treatment of patients with spinal metastases

The sirtuin 6: An overture in skin cancer

In the recent past, the sirtuins have been under intense investigation for their roles in biology and disease, including cancer. The sirtuin SIRT6 is comparatively a lesser studied member of this family of seven proteins. Like certain other sirtuins, SIRT6 is emerging to have an oncogenic function as well as tumor suppressor roles in cancer. Limited studies have been conducted assessing the role and functional significance of SIRT6 in melanoma and non-melanoma skin cancers. In this review, we have attempted to critically dissect the potential role and significance of SIRT6 in skin carcinogenesis. With limited available information to date, SIRT6 appears to have a pro-proliferative function in non-melanoma skin cancers (NMSCs), including squamous cell carcinoma (SCC) and basal cell carcinoma (BCC). In addition, SIRT6 is also emerging to have an oncogenic function in melanoma. Moreover, we have provided information regarding the available SIRT6 inhibitors. Conclusively, it appears that additional comprehensive studies are needed to establish the role of SIRT6 in skin biology and skin diseases, including cancer. Further, concerted efforts are needed to characterize the stage-specific role of SIRT6 in skin cancers.

[Digital ischaemia with fingertip ulcers during ipilimumab therapy]

BACKGROUND

Anti-cancer drugs have many adverse effects including vascular side effects. Herein we present the case of a patient presenting digital ischaemia with high imputability of ipilimumab.

OBSERVATION

A 47-year-old male patient was treated for popliteal melanoma, initially stage IIIA but which subsequently became metastatic (stage IV), and for which ipilimumab was given after the failure of two lines of chemotherapy. During the 4th course of ipilimumab, the patient developed autoimmune hepatitis. Ipilimumab was suspended. Three months later, he developed a drug-like neuropathy followed one month later by ulceration of the right index finger. Causes of embolic, autoimmune and occupational origin (thrombotic microangiopathy, thrombosed aneurysm) were rapidly ruled out. Although a paraneoplastic origin could not be formally excluded, drug-induced immune disorder remained the most plausible origin.

DISCUSSION

This is the first reported case of digital ulceration under ipilimumab.

Utility of the RIG-I Agonist Triphosphate RNA for Melanoma Therapy

The pattern recognition receptor RIG-I plays an important role in the recognition of nonself RNA and antiviral immunity. RIG-I's natural ligand, triphosphate RNA (ppp-RNA), is proposed to be a valuable addition to the growing arsenal of cancer immunotherapy treatment options. In this study, we present comprehensive data validating the concept and utility of treatment with synthetic RIG-I agonist ppp-RNA for the therapy of human cancer, with melanoma as potential entry indication amenable to intratumoral treatment. Using mRNA expression data of human tumors, we demonstrate that RIG-I expression is closely correlated to cellular and cytokine immune activation in a wide variety of tumor types. Furthermore, we confirm susceptibility of cancer cells to ppp-RNA treatment in different cellular models of human melanoma, revealing unexpected heterogeneity between cell lines in their susceptibility to RNA agonist features, including sequence, secondary structures, and presence of triphosphate. Cellular responses to RNA treatment (induction of type I IFN, FasR, MHC-I, and cytotoxicity) were demonstrated to be RIG-I dependent using KO cells. Following ppp-RNA treatment of a mouse melanoma model, we observed significant local and systemic antitumor effects and survival benefits. These were associated with type I IFN response, tumor cell apoptosis, and innate and adaptive immune cell activation. For the first time, we demonstrate systemic presence of tumor antigen-specific CTLs following treatment with RIG-I agonists. Despite potential challenges in the generation and formulation of potent RIG-I agonists, ppp-RNA or analogues thereof have the potential to play an important role for cancer treatment in the next wave of immunotherapy.

Design, synthesis, and anticancer evaluation of novel quinoline derivatives of ursolic acid with hydrazide, oxadiazole, and thiadiazole moieties as potent MEK inhibitors

In this article, a series of novel quinoline derivatives of ursolic acid (UA) bearing hydrazide, oxadiazole, or thiadiazole moieties were designed, synthesised, and screened for their in vitro antiproliferative activities against three cancer cell lines (MDA-MB-231, HeLa, and SMMC-7721). A number of compounds showed significant activity against at least one cell line. Among them, compound 4d exhibited the most potent activity against three cancer cell lines with IC50 values of 0.12 ± 0.01, 0.08 ± 0.01, and 0.34 ± 0.03 μM, respectively. In particular, compound 4d could induce the apoptosis of HeLa cells, arrest cell cycle at the G0/G1 phase, elevate intracellular reactive oxygen species level, and decrease mitochondrial membrane potential. In addition, compound 4d could significantly inhibit MEK1 kinase activity and impede Ras/Raf/MEK/ERK transduction pathway. Therefore, compound 4d may be a potential anticancer agent and a promising lead worthy of further investigation.

Anti-PD-1 immunotherapy in advanced metastatic melanoma: State of the art and future challenges

Immunotherapy with immune checkpoint inhibitors, such as anti-PD-1 drugs, is an area in increasing development for its efficacy and advantages in the treatment of advanced metastatic melanoma. In fact, immunotherapy has been the target of several and recent studies in different types of cancer, namely in melanoma, a globally growing threat. Contributing to the increasing incidence of this cancer is climate change, particularly global warming of the past century, which has increased the tendency to spend more time outdoors and, consequently, exposure to sunlight and ultraviolet radiation. Among the most relevant risk factors for melanoma is the increase in ultraviolet radiation due to ozone layer depletion, one of the main factors responsible for the incidence of new cases. Anti-PD-1 agents like Nivolumab and Pembrolizumab allow a more effective treatment, enhancing the duration of the responses to therapy and prolonging the survival of the patient. However, recent studies about safety and tolerability have stated that, although these drugs present less adverse effects and toxicity, they may lead to specific autoimmune-mediated adverse events. Overall, immunotherapy with anti-PD-1 agents represents a highly promising area in the treatment of some types of cancer such as melanoma.

Identification of 15 T Cell Restricted Genes Evaluates T Cell Infiltration of Human Healthy Tissues and Cancers and Shows Prognostic and Predictive Potential

T cell gene signatures are used to evaluate T cell infiltration of non-lymphoid tissues and cancers in both experimental and clinical settings. However, some genes included in the available T cell signatures are not T cell-restricted. Herein, we propose a new human T cell signature that has been developed via a six-step procedure and comprises 15 T cell restricted genes. We demonstrate the new T cell signature, named signature-H, that differs from other gene signatures since it shows higher sensitivity and better predictivity in the evaluation of T cell infiltration in healthy tissues as well as 32 cancers. Further, results from signature-H are highly concordant with the immunohistochemistry methods currently used for assessing the prognosis of neuroblastoma, as demonstrated by the Kaplan–Meier curves of patients ranked by tumor T cell infiltration. Moreover, T cell infiltration levels calculated using signature-H correlate with the risk groups determined by the staging of the neuroblastoma. Finally, multiparametric analysis of tumor-infiltrating T cells based on signature-H let us favorably predict the response of melanoma to the anti-PD-1 antibody nivolumab. These findings suggest that signature-H evaluates T cell infiltration levels of tissues and may be used as a prognostic tool in the precision medicine perspective after appropriate clinical validation.

In vitro selective cytotoxicity of the dietary chalcone cardamonin (CD) on melanoma compared to healthy cells is mediated by apoptosis

Malignant melanoma is an aggressive type of cancer and the deadliest form of skin cancer. Even though enormous efforts have been undertaken, in particular the treatment options against the metastasizing form are challenging and the prognosis is generally poor. A novel therapeutical approach is the application of secondary plant constituents occurring in food and food products. Herein, the effect of the dietary chalcone cardamonin, inter alia found in Alpinia species, was tested using human malignant melanoma cells. These data were compared to cardamonin treated normal melanocytes and dermal fibroblasts representing healthy cells. To investigate the impact of cardamonin on tumor and normal cells, it was added to monolayer cell cultures and cytotoxicity, proliferation, tumor invasion, and apoptosis were studied with appropriate cell biological and biochemical methods. Cardamonin treatment resulted in an apoptosis-mediated increase in cytotoxicity towards tumor cells, a decrease in their proliferation rate, and a lowered invasive capacity, whereas the viability of melanocytes and fibroblasts was hardly affected at such concentrations. A selective cytotoxic effect of cardamonin on melanoma cells compared to normal (healthy) cells was shown in vitro. This study along with others highlights that dietary chalcones may be a valuable tool in anticancer therapies which has to be proven in the future in vivo.

In Vivo ERK1/2 Reporter Predictively Models Response and Resistance to Combined BRAF and MEK Inhibitors in Melanoma

Combined BRAF and MEK inhibition is a standard of care in patients with advanced BRAF-mutant melanoma, but acquired resistance remains a challenge that limits response durability. Here, we quantitated in vivo ERK1/2 activity and tumor response associated with resistance to combined BRAF and MEK inhibition in mutant BRAF xenografts. We found that ERK1/2 pathway reactivation preceded the growth of resistant tumors. Moreover, we detected a subset of cells that not only persisted throughout long-term treatment but restored ERK1/2 signaling and grew upon drug removal. Cell lines derived from combination-resistant tumors (CRT) exhibited elevated ERK1/2 phosphorylation, which were sensitive to ERK1/2 inhibition. In some CRTs, we detected a tandem duplication of the BRAF kinase domain. Monitoring ERK1/2 activity in vivo was efficacious in predicting tumor response during intermittent treatment. We observed maintained expression of the mitotic regulator, polo-like kinase 1 (Plk1), in melanoma resistant to BRAF and MEK inhibitors. Plk1 inhibition induced apoptosis in CRTs, leading to slowed growth of BRAF and MEK inhibitor-resistant tumors in vivo These data demonstrate the utility of in vivo ERK1/2 pathway reporting as a tool to optimize clinical dosing schemes and establish suppression of Plk1 as potential salvage therapy for BRAF inhibitor and MEK inhibitor-resistant melanoma.

A novel spheroid-based co-culture model mimics loss of keratinocyte differentiation, melanoma cell invasion, and drug-induced selection of ABCB5-expressing cells

Background

Different 3D-cell culture approaches with varying degrees of complexity have been developed to serve as melanoma models for drug testing or mechanistic studies. While these 3D-culture initiatives are already often superior to classical 2D approaches, they are either composed of only melanoma cells or they are so complex that the behavior of individual cell types is hard to understand, and often they are difficult to establish and expensive.

Methods

This study used low-attachment based generation of spheroids composed of up to three cell types. Characterization of cells and spheroids involved cryosectioning, immunofluorescence, FACS, and quantitative analyses. Statistical evaluation used one-way ANOVA with post-hoc Tukey test or Student’s t-test.

Results

The tri-culture model allowed to track cellular behavior in a cell-type specific manner and recapitulated different characteristics of early melanoma stages. Cells arranged into a collagen-IV rich fibroblast core, a ring of keratinocytes, and groups of highly proliferating melanoma cells on the outside. Regularly, some melanoma cells were also found to invade the fibroblast core. In the absence of melanoma cells, the keratinocyte ring stratified into central basal-like and peripheral, more differentiated cells. Conversely, keratinocyte differentiation was clearly reduced upon addition of melanoma cells. Treatment with the cytostatic drug, docetaxel, restored keratinocyte differentiation and induced apoptosis of external melanoma cells. Remaining intact external melanoma cells showed a significantly increased amount of ABCB5-immunoreactivity.

Conclusions

In the present work, a novel, simple spheroid-based melanoma tri-culture model composed of fibroblasts, keratinocytes, and melanoma cells was described. This model mimicked features observed in early melanoma stages, including loss of keratinocyte differentiation, melanoma cell invasion, and drug-induced increase of ABCB5 expression in external melanoma cells.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5606-4) contains supplementary material, which is available to authorized users.

Plasma-activated medium triggers cell death and the presentation of immune activating danger signals in melanoma and pancreatic cancer cells

Over the past decade, cold atmospheric plasmas have shown promising application in cancer therapy. The therapeutic use of plasma-activated media is a topic addressed in an emerging field known as plasma pharmacy. In oncology, plasma-activated media are  used to harness the therapeutic effects of oxidant species when they come in contact with cancer cells. Among several factors that contribute to the anticancer effect of plasma-activated liquid media (PALM), H₂O₂ and NO derivatives likely play a key role in the apoptotic pathway. Despite the significant amount of literature produced in recent years, a full understanding of the mechanisms by which PALM exert their activity against cancer cells is limited. In this paper, a sealed dielectric-barrier discharge was used to disentangle the effect of reactive nitrogen species (RNS) from that of reactive oxygen species (ROS) on cancer cells. Two cancers characterized by poor prognosis have been investigated: metastatic melanoma and pancreatic cancer. Both tumour models exposed to PALM rich in H₂O₂ showed a reduction in proliferation and an increase in calreticulin exposure and ATP release, suggesting the potential use of activated media as an inducer of immunogenic cell death via activation of the innate immune system.

A perspective on the diagnostics, prognostics, and therapeutics of microRNAs of triple-negative breast cancer

Triple-negative breast cancer (TNBC) is the most aggressive and prevalent subtype of breast cancer in women worldwide. Currently, chemotherapy remains the main modality for the treatment at an early stage, as there is no approved targeted therapy for early TNBC. In this review, we investigate the use of microRNAs (miRNAs), which play a key role in the post-transcriptional regulation of genes involved in the key biological processes, namely proliferation, differentiation, angiogenesis, migration, apoptosis, and carcinogenesis. Here, we emphasize the importance of the recent advances related to miRNAs, involving diagnosis, prognosis, and treatment of TNBC. We focus on the development, optimization, and stabilization of miRNA-based drugs; improvement of miRNA delivery; and control of the off-target effects of miRNA therapeutics. We speculate as to which features may present themselves as promising approaches in the treatment of TNBC.

Lopinavir-NO, a nitric oxide-releasing HIV protease inhibitor, suppresses the growth of melanoma cells in vitro and in vivo

We generated a nitric oxide (NO)-releasing derivative of the anti-HIV protease inhibitor lopinavir by linking the NO moiety to the parental drug. We investigated the effects of lopinavir and its derivative lopinavir-NO on melanoma cell lines in vitro and in vivo. Lopinavir-NO exhibited a twofold stronger anticancer action than lopinavir in vitro. These results were successfully translated into syngeneic models of melanoma in vivo, where a significant reduction in tumour volume was observed only in animals treated with lopinavir-NO. Both lopinavir and lopinavir-NO inhibited cell proliferation and induced the trans-differentiation of melanoma cells to Schwann-like cells. In melanoma cancer cell lines, both lopinavir and lopinavir-NO induced morphological changes, minor apoptosis and reactive oxygen species (ROS) production. However, caspase activation and autophagy were detected only in B16 cells, indicating a cell line-specific treatment response. Lopinavir-NO released NO intracellularly, and NO neutralization restored cell viability. Treatment with lopinavir-NO induced only a transient activation of Akt and inhibition of P70S6 kinase. The results of this study identify lopinavir-NO as a promising candidate for further clinical trials in melanoma and possibly other solid tumours.

Economic Evaluation of Talimogene Laherparepvec Plus Ipilimumab Combination Therapy vs Ipilimumab Monotherapy in Patients With Advanced Unresectable Melanoma

Importance

A phase 2 trial comparing talimogene laherparepvec plus ipilimumab vs ipilimumab monotherapy in patients with advanced unresectable melanoma found no differential benefit in progression-free survival (PFS) but noted objective response rates (ORRs) of 38.8% (38 of 98 patients) vs 18.0% (18 of 100 patients), respectively.

Objective

To perform an economic evaluation of talimogene laherparepvec plus ipilimumab combination therapy vs ipilimumab monotherapy.

Design, Setting, and Participants

For PFS, cost-effectiveness and cost-utility analyses using a 2-state Markov model (PFS vs progression or death) was performed. For ORRs, cost-effectiveness analysis of the incremental cost of 1 additional patient achieving objective response was performed. In this setting based on a US payer perspective (2017 US dollars), participants were patients with advanced unresectable melanoma.

Main Outcomes and Measures

The PFS life-years and PFS quality-adjusted life-years were determined, and the associated incremental cost-effectiveness ratios (ICERs) and incremental cost-utility ratios (ICURs) were estimated. Also estimated was the ICER per 1 additional patient (out of 100 treated patients) achieving objective response. Base-case analyses were validated by sensitivity analyses.

Results

In PFS analyses, the cost of talimogene laherparepvec plus ipilimumab ($494 983) exceeded the cost of ipilimumab monotherapy ($132 950) by $362 033. The ICER was $2 129 606 per PFS life-years, and the ICUR was $2 262 706 per PFS quality-adjusted life-year gained. Probabilistic sensitivity analyses yielded an ICER of $1 481 208 per PFS life-year gained and an ICUR of $1 683 191 per PFS quality-adjusted life-year gained. In 1-way sensitivity analyses, the PFS hazard ratio and the utility of response were the most influential parameters. Talimogene laherparepvec plus ipilimumab has a 50% likelihood of being cost-effective at a willingness-to-pay threshold of $1 683 191 per PFS quality-adjusted life-year gained. In ORR analyses, talimogene laherparepvec plus ipilimumab ($474 904) vs ipilimumab alone ($132 810), a $342 094 difference, yielded an ICER of $1 629 019 per additional patient achieving objective response. In subgroup analyses by disease stage and BRAFV600E mutation status, ICERs ranged from $1 069 044 to $17 104 700 per 1 additional patient achieving objective response.

Conclusions and Relevance

The cost to gain 1 additional progression-free quality-adjusted life-year, 1 additional progression-free life-year, or to have 1 additional patient attain objective response is about $1.6 million. This amount may be beyond what payers typically are willing to pay. Combination therapy of talimogene laherparepvec plus ipilimumab does not offer an economically beneficial treatment option relative to ipilimumab monotherapy at the population level. This should not preclude treatment for individual patients for whom this regimen may be indicated.