Melanoma Management: From Epidemiology to Treatment and Latest Advances

Combination of gold nanoparticles with near-infrared light as an alternative approach for melanoma management

Melanoma is the most aggressive type of skin cancer and recently approved drugs are often associated with resistance and significant adverse effects. Therefore, the design of more effective and safe options remains imperative. Photothermal therapy (PTT) using gold nanoparticles (AuNPs) presents a promising and innovative approach. In this work, the efficacy of combining a previously optimized formulation of AuNPs coated with a mixture of hyaluronic and oleic acids (HAOA-AuNPs) with near-infrared (NIR) laser irradiation in melanoma cell lines was explored. Coated and uncoated AuNPs formulations were characterized in physicochemical, morphological and elemental terms. Next, the cellular uptake efficiency as well as antiproliferative activity of the combination of each formulation with laser irradiation was evaluated. Subsequently, HAOA-AuNPs were selected to assess the underlying mechanism of combined therapy by cell cycle and Annexin V/PI assays. An in vivo syngeneic murine melanoma model was also conducted. In vitro studies demonstrated that 24 h after incubation and in the absence of laser, HAOA-AuNPs did not exhibit cytotoxic effects on the melanoma cell lines tested, similar to the laser alone. On the contrary, the combination therapy resulted in a large reduction in cell viability. Furthermore, it has been shown to promote S-phase cell cycle arrest and increase in the percentage of late apoptotic cells. Finally, the in vivo proof-of-concept showed that the intratumoral administration of HAOA-AuNPs followed by three laser irradiations impaired tumor progression. Collectively, AuNP-based PTT holds significant potential to improve treatment efficacy and safety, offering a versatile and potent tool against cancer.

Cedrus atlantica extract inhibits melanoma progression by suppressing epithelial-mesenchymal transition and inducing mitochondria-mediated apoptosis

Melanoma has a low incidence, accounting for less than 5% of skin cancers; however, it is the most lethal cancer, primarily because of its high potential for metastasis and resistance to different treatments. Natural products can sensitize melanoma to chemotherapy and overcome drug resistance. Previous studies have reported Cedrus atlantica extract has various pharmacological benefits such as anti-inflammatory, antioxidant, antibacterial, and analgesic properties. This study aimed to explore the effects of C. atlantica extract (CAt) against melanoma in vitro and in vivo. The effects of CAt on B16F10 cell viability, proliferation, migration, invasion, and apoptosis were detected using MTT, colony formation, wound-healing, Boyden chamber, and TUNEL assays. Semi-quantitative RT-PCR and western blotting were used to measure mRNA and protein expression, respectively. Results revealed that CAt selectively decreased the viability of B16F10 cells and inhibited colony formation in a dose-dependent manner. CAt reduces cell migration and invasion by regulating epithelial-mesenchymal transition-associated proteins (Snail, E-cadherin, and vimentin). Moreover, CAt enhanced the Bax/Bcl-2 ratio and the expression of cleaved-caspase-9, caspase-3, and PARP1, resulting in the activation of mitochondria-mediated apoptosis. In an in vivo study, CAt significantly inhibited tumor growth and prolonged the lifespan of mice at a well-tolerated dose. Importantly, the combination of CAt and 5-fluorouracil (5-FU) exhibited synergistic growth suppression and attenuated the development of 5-FU resistance. Overall, the findings suggest that CAt holds promise as a potential drug or adjuvant to improve melanoma treatment.

An ionic liquid-based delivery system of small interfering RNA targeting Bcl-2 for melanoma therapy

Melanoma, characterized by rapid tumour progression and a strong tendency to metastasize, poses significant challenges in clinical treatment. Given the vital role of B-cell lymphoma 2 (Bcl-2) protein overexpression in inhibiting apoptosis in tumour cells, the suppression of Bcl-2 has emerged as a promising anticancer therapy. Here, we have developed a straightforward and effective delivery system that combines small interfering RNA (siRNA) targeting Bcl-2 (siBcl-2) with ionic liquids (ILs) for treating melanoma. The unique properties of ILs including structural tunability, inherent charge, and chemical stability have garnered significant attention in the biomedical fields; however, their application in siRNA delivery remains nascent. Rather than the weak function of free siBcl-2, our delivery system (1-hexyl-3-methylimidazolium-siBcl-2, designated as C6-siBcl-2) demonstrated an outstanding capacity to improve the cellular uptake and lysosomal escape, resulting in robust apoptosis and cytotoxicity in melanoma cells. In addition to exhibiting superior gene silencing activity in vitro, such events were also evident in mice bearing melanoma tumours. In particular, this IL-based delivery system showed advantages in suppressing tumour growth, preventing metastasis, and enhancing the survival time of mice with melanoma tumours. Therefore, our study offered a novel and powerful nanoplatform that integrated ILs and RNA interference therapy, presenting new strategies for cancer treatment.

cGAS/STING in skin melanoma: from molecular mechanisms to therapeutics

Melanoma, recognized as the most aggressive type of skin cancer, has experienced a notable increase in cases, especially within populations with fair skin. This highly aggressive cancer is largely driven by UV radiation exposure, resulting in the uncontrolled growth and malignant transformation of melanocytes. The cGAS-STING pathway, an immune signaling mechanism responsible for detecting double-stranded DNA in the cytoplasm, is essential for mediating the immune response against melanoma. This pathway serves a dual purpose: it enhances antitumor immunity by activating immune cells, but it can also promote tumor growth when chronically activated by creating an immunosuppressive environment. This review comprehensively examines the multifaceted implication of the cGAS-STING pathway in melanoma pathogenesis and treatment. We explore its molecular mechanisms, including epigenetic regulation, interaction with signaling pathways such as AR signaling, and modulation by various cellular effectors like TG2 and activin-A. The therapeutic potential of modulating the cGAS-STING pathway is highlighted, with promising results from STING agonists, combination therapies with immune checkpoint inhibitors, and novel drug delivery systems, including nanoparticles and synthetic drugs. Our findings underscore the importance of the cGAS-STING pathway in melanoma, presenting it as a critical target for enhancing anti-tumor immunity. By leveraging this pathway, future therapeutic strategies can potentially convert 'cold' tumors into 'hot' tumors, making them more susceptible to immune responses.

Reconnoitring signaling pathways and exploiting innovative approaches tailoring multifaceted therapies for skin cancer

Nowadays, skin cancer is widespread just like a varied malignant cancer which can cause serious health issues. Skin cancer, which encompasses malignant melanoma, basal cell carcinoma, and squamous cell carcinoma, is a prevalent form of cancer among humans. Due to its broad prevalence, financial burden, mortality rates, and cosmetic effects, it is a major public health issue. Skin cancer treatment involves surgery, chemotherapy, and radiation. Recently, personalized treatment in the fields of targeted therapies and precision medicine has been shown to diagnose early detection of every individual tumor by knowing their genetic and molecular characteristics. To target the molecular pathways responsible for tumor growth and reduce the damage to healthy tissue, new targeted therapies have emerged for melanoma, basal cell carcinoma, and squamous cell carcinoma. B-raf serine/threonine kinase (BRAF) and mitogen-activated protein kinase (MEK) inhibitors, immune checkpoint inhibitors, and precision medications have strong response rates to improve patient survival. Targeted therapeutics like nanocarriers have shown promising results by reducing skin irritation and protecting encapsulated therapeutics. These formulations have been shown to improve the transdermal permeability of anticancer drugs. The consideration of employing physical techniques to enhance the permeation of nanocarriers warrants attention to augment the dermal permeation of anticancer agents and facilitate targeted drug delivery within neoplastic cells. Targeted therapies face obstacles like resistance mechanisms and treatment strategy monitoring. Taken together, this review delves into the basic mechanisms of skin cancer, current treatment methods, drug resistance processes, and nano-based targeted techniques for cancer treatment. It will also delineate the challenges and perspectives in pre-clinical and clinical contexts.

The roles of cancer stem cells and therapeutic implications in melanoma

Melanoma is a highly malignant skin tumor characterized by high metastasis and poor prognosis. Recent studies have highlighted the pivotal role of melanoma stem cells (MSCs)-a subpopulation of cancer stem cells (CSCs)-in driving tumor growth, metastasis, therapeutic resistance, and recurrence. Similar to CSCs in other cancers, MSCs possess unique characteristics, including specific surface markers, dysregulated signaling pathways, and the ability to thrive within complex tumor microenvironment (TME). This review explored the current landscape of MSC research, discussing the identification of MSC-specific surface markers, the role of key signaling pathways such as Wnt/β-catenin, Notch, and Hedgehog (Hh), and how interactions within the TME, including hypoxia and immune cells, contribute to MSC-mediated drug resistance and metastatic behavior. Furthermore, we also investigated the latest therapeutic strategies targeting MSCs, such as small-molecule inhibitors, immune-based approaches, and novel vaccine developments, with an emphasis on their potential to overcome melanoma progression and improve clinical outcomes. This review aims to provide valuable insights into the complex roles of MSCs in melanoma biology and offers perspectives for future research and therapeutic advances against this challenging disease.

Synthesis, physicochemical and pharmacological characterizations of a tetra-[methylimidazolium] dihydrogen decavanadate, inhibiting the IGR39 human melanoma cells development

Melanoma is a skin cancer that arises from melanocytes and can spread quickly to the other organs of the body, if not treated early. Generally, melanoma shows an inherent resistance to conventional therapies. In this regard, new potential drugs are being developed as possible treatments for melanoma. In this paper, we report the synthesis of a new decavanadate compound with organic molecules for a potential therapeutic application. The tetra-[methylimidazolium] dihydrogen decavanadate(V) salt (C4H7N2)4[H2V10O28] is characterized by single-crystal X-ray diffraction, by FT-IR, UV-Vis and 51V NMR spectroscopy, as well as by thermal analysis (TGA and DSC). The compound crystallizes in the monoclinic centrosymmetric space group P21/c. Its formula unit consists of one dihydrogen decavanadate anion [H2V10O28]4- and four organic 4-methylimidazolium cations (C4H7N2)+. Important intermolecular interactions are N-H···O and O-H···O hydrogen bonds and π-π stacking interactions between the organic cations, revealed by analysis of the Hirshfeld surface and its two-dimensional fingerprint plots. Interestingly, this compound inhibits the viability of IGR39 cells with IC50 values of 14.65 μM and 4 μM after 24 h and 72 h of treatment, respectively. The analysis of its effect by flow cytometry using an Annexin V-FITC/IP cell labeling, showed that (C4H7N2)4H2V10O28 compound induced IGR39 cell apoptosis and necrosis. Molecular docking studies performed against TNFR1 and GPR40, as putative targets, suggest that the (C4H7N2)4[H2V10O28] compound may act as inhibitor of these proteins, known to be overexpressed in melanoma cells. Therefore, we could consider it as a new potential metallodrug against melanoma.

Exosome-based immunotherapy as an innovative therapeutic approach in melanoma

The malignant form of melanoma is one of the deadliest human cancers that accounts for almost all of the skin tumor-related fatalities in its later stages. Achieving an exhaustive understanding of reliable cancer-specific markers and molecular pathways can provide numerous practical techniques and direct the way toward the development of rational curative medicines to increase the lifespan of patients. Immunotherapy has significantly enhanced the treatment of metastatic and late-stage melanoma, resulting in an incredible increase in positive responses to therapy. Despite the increasing occurrence of melanoma, the median survival rate for patients with advanced, inoperable terminal disease has increased from around six months to almost six years. The current knowledge of the tumor microenvironment (TME) and its interaction with the immune system has resulted in the swift growth of innovative immunotherapy treatments. Exosomes are small extracellular vesicles (EVs), ranging from 30 to 150 nm in size, that the majority of cells released them. Exosomes possess natural advantages such as high compatibility with living organisms and low potential for causing immune reactions, making them practical for delivering therapeutic agents like chemotherapy drugs, nucleic acids, and proteins. This review highlights recent advancements in using exosomes as an approach to providing medications for the treatment of melanoma.

Combining Phototherapy and Gold-Based Nanomaterials: A Breakthrough in Basal Cell Carcinoma Treatment

Basal cell carcinoma (BCC) is the most common type of skin carcinoma worldwide. BCC development is the result of a complex interaction between environmental, phenotypic, and genetic factors. While conventional treatments such as surgery and topical therapies have demonstrated variable efficacy (some of them with limited efficacy), they are not free of adverse side effects, most of them debilitating. Thus, there is a notable gap in the literature regarding alternative and non-invasive therapeutic options. This review aims to address this gap, exploring the potential of photothermal therapy (PTT) combined with metallic nanoparticles, namely gold nanoparticles (AuNPs), as a minimally invasive treatment approach. Through a comprehensive review of the literature in the period from 2014 to 2024, using experimental investigations, this review seeks to elucidate the intricate interplay between genetic factors, environmental influences, and the tumor microenvironment in BCC disease progression, with PTT as a potential therapeutic strategy. Those studies confirmed an enhanced targeting of cancer cells and selective ablation of tumor tissue, using emerging technologies like PTT. A significant tumor reduction, often exceeding 50%, was observed, with some studies reporting complete elimination of the tumor. The main adverse effects noted were localized skin irritation and transient hyperpigmentation, but these were generally minimal and manageable, highlighting the promise of PTT as an effective treatment. Thus, by leveraging the unique properties of AuNPs to enhance the effectiveness of PTT, the targeting of cancer cells can more precisely occur, reducing collateral damage to healthy tissues. This approach not only aims to achieve better clinical results, but also contributes to the broader knowledge base in the field of BCC research. Continued research and clinical trials will be crucial in refining those techniques and validating their efficacy, ultimately paving the way for more effective and less invasive treatments for BCC.

Autophagy as a targeted therapeutic approach for skin cancer: Evaluating natural and synthetic molecular interventions

Skin cancer, a prevalent malignancy worldwide, poses significant health concerns owing to its increasing incidence. Autophagy, a natural cellular process, is a pivotal event in skin cancer and has advantageous and detrimental effects. This duality has prompted extensive investigations into medical interventions targeting autophagy modulation for their substantial therapeutic potential. This systematic review aimed to investigate the relationship between skin cancer and autophagy and the contribution and mechanism of autophagy modulators in skin cancer. We outlined the effectiveness and safety of targeting autophagy as a promising therapeutic strategy for the treatment of skin cancer. This comprehensive review identified a diverse array of autophagy modulators with promising potential for the treatment of skin cancer. Each of these compounds demonstrates efficacy through distinct physiological mechanisms that have been elucidated in detail. Interestingly, findings from a literature search indicated that none of the natural, synthetic, or semisynthetic compounds exhibited notable adverse effects in either human or animal models. Consequently, this review offers novel mechanistic and therapeutic perspectives on the targeted modulation of autophagy in skin cancer.

Trends in Melanoma Incidence, Prevalence, Stage at Diagnosis, and Survival: An Analysis of the United States Cancer Statistics (USCS) Database

Background and objectives Melanoma, a major skin cancer, has seen varying trends in incidence, prevalence, stage at diagnosis, and survival. This study examines these trends using the United States Cancer Statistics (USCS) database, covering the period from 1999 to 2021. Methods We extracted data from the USCS database, which integrates the National Cancer Institute's (NCI) Surveillance, Epidemiology, and End Results (SEER) program and the Centers for Disease Control and Prevention's (CDC) National Program of Cancer Registries (NPCR). The analysis included new melanoma cases, prevalence estimates (using a 20-year limited duration), stage at diagnosis, and five-year relative survival rates. Incidence rates were adjusted for age using the 2000 United States standard population. Descriptive and trend analyses were performed using IBM SPSS Statistics software, version 29 (IBM Corp., Armonk, NY).  Results The analysis of melanoma trends from 1999 to 2021 reveals a significant increase in the annual age-adjusted incidence rate, rising from 15.1 per 100,000 (95% CI: 14.9- 15.2) in 1999 to 23.0 per 100,000 (95% CI: 22.8- 23.1) in 2021. This upward trend is consistent across gender and racial/ethnic groups. The prevalence of melanoma over a 20-year period was 0.279 (95% CI: 0.276-0.282), with males showing a higher prevalence (0.302, 95% CI: 0.298-0.306) compared to females (0.256, 95% CI: 0.252-0.260). The distribution of melanoma stage at diagnosis indicated that 77% of cases were localized (95% CI: 76.5-77.5%), 9.5% regional (95% CI: 9.2-9.8%), 4.7% distant (95% CI: 4.4-5.0%), and 8.8% unstaged (95% CI: 8.5-9.1%). Survival analysis showed a five-year relative survival rate of 99.4% (95% CI: 99.2-99.6%) for localized melanoma and 35.6% (95% CI: 33.7-37.6%) for distant melanoma, highlighting significant disparities in survival based on stage at diagnosis. Conclusions The study highlights a rising incidence of melanoma and emphasizes the critical role of early detection in improving survival outcomes. The findings underscore the effectiveness of early diagnosis and the necessity for ongoing efforts to improve melanoma outcomes across diverse populations.

Tumor lysis syndrome signal with the combination of encorafenib and binimetinib for malignant melanoma: a pharmacovigilance study using data from the FAERS database

Objective

To investigate the potential association between tumor lysis syndrome (TLS) and drugs for the treatment of malignant melanoma (MM).

Methods

Reports of TLS recorded in the FDA Adverse Event Reporting System (FAERS) (January 2004-2023q3) were identified. Demographic and clinical characteristics were described, and disproportionality signals were assessed through the Reporting Odds Ratio (ROR) and Information Component (IC). The latency of TLS with anticancer drugs was described based on parametric models. Subgroup analysis was conducted to explore the differences of TLS signals in different age and sex.

Results

We found 5 (1.49%), 59 (17.61%), 79 (23.58%), 19 (5.67%), 13 (3.88%), 13 (3.88%), 33 (9.85%), 49 (14.63%), 16 (4.78%) TLS reports with pembrolizumab, nivolumab, ipilimumab, dabrafenib, vemurafenib, dacarbazine, "encorafenib and binimetinib", "nivolumab and ipilimumab", "dabrafenib and trametinib", respectively. The combination of encorafenib and binimetinib showed the strongest signal of TLS (IC025 = 3.98). The median days of latency of TLS with combination of encorafenib and binimetinib is 2 days, which was much shorter than nivolumab (22.0 days) and ipilimumab (21.5 days). TLS cases associated with drugs for MM were predominantly recorded in females and aged 25-65 years. After excluding confounding factors such as pre-existing diseases and co-treated drugs, the disproportionate signal of TLS with "encorafenib and binimetinib" remained strong.

Conclusions

Stronger disproportionate signal of TLS was detected in MM patients using the combination of encorafenib and binimetinib than other drugs. Further research is needed to investigate the underlying mechanisms and identify patient-related predisposing factors to support safe prescribing of the combination of encorafenib and binimetinib.

Extract of Araçá-Boi and Its Major Phenolic Compound, Trans-Cinnamic Acid, Reduce Viability and Inhibit Migration of Human Metastatic Melanoma Cells

Cutaneous melanoma is an aggressive type of skin cancer that is recognized for its high metastatic potential and the challenges it presents in its treatment. There has been increasing interest in plant extracts and their potential applications in melanoma. The present study aimed to investigate the content of individual phenolic compounds in araçá-boi extract, evaluate their antioxidant activity, and explore their effects on cell viability, migration properties, oxidative stress levels, and protein expression in the human metastatic melanoma cell line SK-MEL-28. HPLC-DAD analysis identified 11 phenolic compounds in the araçá-boi extract. Trans-cinnamic acid was the main phenolic compound identified; therefore, it was used alone to verify its contribution to antitumor activities. SK-MEL-28 melanoma cells were treated for 24 h with different concentrations of araçá-boi extract and trans-cinnamic acid (200, 400, 600, 800, and 1600 µg/mL). Both the araçá-boi extract and trans-cinnamic acid reduced cell viability, cell migration, and oxidative stress in melanoma cells. Additionally, they modulate proteins involved in apoptosis and inflammation. These findings suggest the therapeutic potential of araçá-boi extract and its phenolic compounds in the context of melanoma, especially in strategies focused on preventing metastasis. Additional studies, such as the analysis of specific signaling pathways, would be valuable in confirming and expanding these observations.

Tumor-Intrinsic Galectin-3 Suppresses Melanoma Metastasis

Melanoma poses a poor prognosis with high mortality rates upon metastasis. Exploring the molecular mechanisms governing melanoma progression paves the way for developing novel approaches to control melanoma metastasis and ultimately enhance patient survival rates. Extracellular galectin-3 (Gal-3) has emerged as a pleiotropic promoter of melanoma metastasis, exerting varying activities depending on its interacting partner. However, whether intracellular Gal-3 promotes melanoma aggressive behavior remains unknown. In this study, we explored Gal-3 expression in human melanoma tissues as well as in murine melanoma models to examine its causal role in metastatic behavior. We found that Gal-3 expression is downregulated in metastatic melanoma tissues compared with its levels in primary melanomas. Enforced silencing of Gal-3 in melanoma cells promoted migration, invasion, colony formation, in vivo xenograft growth, and metastasis and activated canonical oncogenic signaling pathways. Moreover, loss of Gal-3 in melanoma cells resulted in upregulated the expression of the prometastatic transcription factor NFAT1 and its downstream metastasis-associated proteins, matrix metalloproteinase 3, and IL-8. Overall, our findings implicate melanoma intracellular Gal-3 as a major determinant of its metastatic behavior and reveal a negative regulatory role for Gal-3 on the expression of NFAT1 in melanoma cells.

Artificial intelligence-assisted metastasis and prognosis model for patients with nodular melanoma

OBJECTIVE

The objective of this study was to identify the risk factors that influence metastasis and prognosis in patients with nodular melanoma (NM), as well as to develop and validate a prognostic model using artificial intelligence (AI) algorithms.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was queried for 4,727 patients with NM based on the inclusion/exclusion criteria. Their clinicopathological characteristics were retrospectively reviewed, and logistic regression analysis was utilized to identify risk factors for metastasis. This was followed by employing Multilayer Perceptron (MLP), Adaptive Boosting (AB), Bagging (BAG), logistic regression (LR), Gradient Boosting Machine (GBM), and eXtreme Gradient Boosting (XGB) algorithms to develop metastasis models. The performance of the six models was evaluated and compared, leading to the selection and visualization of the optimal model. Through integrating the prognostic factors of Cox regression analysis with the optimal models, the prognostic prediction model was constructed, validated, and assessed.

RESULTS

Logistic regression analyses identified that marital status, gender, primary site, surgery, radiation, chemotherapy, system management, and N stage were all independent risk factors for NM metastasis. MLP emerged as the optimal model among the six models (AUC = 0.932, F1 = 0.855, Accuracy = 0.856, Sensitivity = 0.878), and the corresponding network calculator (https://shimunana-nm-distant-m-nm-m-distant-8z8k54.streamlit.app/) was developed. The following were examined as independent prognostic factors: MLP, age, marital status, sequence number, laterality, surgery, radiation, chemotherapy, system management, T stage, and N stage. System management and surgery emerged as protective factors (HR < 1). To predict 1-, 3-, and 5-year overall survival (OS), a nomogram was created. The validation results demonstrated that the model exhibited good discrimination and consistency, as well as high clinical usefulness.

CONCLUSION

The developed prediction model more effectively reflects the prognosis of patients with NM and differentiates between the risk level of patients, serving as a useful supplement to the classical American Joint Committee on Cancer (AJCC) staging system and offering a reference for clinically stratified individualized treatment and prognosis prediction. Furthermore, the model enables clinicians to quantify the risk of metastasis in NM patients, assess patient survival, and administer precise treatments.

Melanoma as Subsequent Primary Malignancy in Hematologic Cancer Survivors-A Literature Review

The occurrence of second primary malignancies is becoming increasingly important among cancer survivors. Melanoma, an aggressive neoplasm originating from the melanocytes, is responsible for most skin cancer-related deaths. This review aims to explore the risk of melanoma occurrence as a second primary cancer after the most common subtypes of hematologic neoplasia, a malignant disease originating from myeloid or lymphocytic cell lineages. Chronic lymphocytic leukemia (CLL) and non-Hodgkin lymphoma (NHL) are among the most associated subtypes with melanoma development. We also discuss the underlying hypotheses that may explain the associations between these malignancies and the impact of melanoma on survival. The review emphasizes the importance of increasing awareness of melanoma risk in hematologic cancer survivors, as it can lead to prompt recognition, improved skin surveillance, and better survival outcomes.

Modulation of the Antimelanoma Activity Imparted to Artemisinin Hybrids by the Monoterpene Counterpart

Molecular hybridization is a widely used strategy in drug discovery and development processes that consists of the combination of two bioactive compounds toward a novel entity. In the current study, two libraries of hybrid derivatives coming from the linkage of sesquiterpene counterparts dihydroartemisinin and artesunic acid, with a series of monoterpenes, were synthesized and evaluated by cell viability assay on primary and metastatic melanoma cell lines. Almost all the obtained compounds showed micromolar antimelanoma activity and selectivity toward the metastatic form of this cancer. Four hybrid derivatives containing perillyl alcohol, citronellol, and nerol as monoterpene counterpart emerged as the best compounds of the series, with nerol being active in combination with both sesquiterpenes, dihydroartemisinin and artesunic acid. Preliminary studies on the mechanism of action have shown the dependence of the pharmacological activity of newly synthesized hybrids on the formation of carbon- and oxygen-centered radical species. This study demonstrated the positive modulation of the pharmacodynamic effect of artemisinin semisynthetic derivatives dihydroartemisinin and artesunic acid due to the hybridization with monoterpene counterparts.

1H and 31P Magnetic Resonance Spectroscopic Metabolomic Imaging: Assessing Mitogen-Activated Protein Kinase Inhibition in Melanoma

The MAPK signaling pathway with BRAF mutations has been shown to drive the pathogenesis of 40-60% of melanomas. Inhibitors of this pathway's BRAF and MEK components are currently used to treat these malignancies. However, responses to these treatments are not always successful. Therefore, identifying noninvasive biomarkers to predict treatment responses is essential for personalized medicine in melanoma. Using noninvasive 1H magnetic resonance spectroscopy (1H MRS), we previously showed that BRAF inhibition reduces lactate and alanine tumor levels in the early stages of effective therapy and could be considered as metabolic imaging biomarkers for drug response. The present work demonstrates that these metabolic changes observed by 1H MRS and those assessed by 31P MRS are also found in preclinical human melanoma models treated with MEK inhibitors. Apart from 1H and 31P MRS, additional supporting in vitro biochemical analyses are described. Our results indicate significant early metabolic correlations with response levels to MEK inhibition in the melanoma models and are consistent with our previous study of BRAF inhibition. Given these results, our study supports the potential clinical utility of noninvasive MRS to objectively image metabolic biomarkers for the early prediction of melanoma's response to MEK inhibition.

Fabrication of thiosemicarbazone-based Pd(II) complexes: structural elucidations, catalytic activity towards Suzuki-Miyaura coupling reaction and antitumor activity against TNBC cells

Currently, there are many uses of metal complexes, especially in the fields of medicinal chemistry and catalysis. Thus, fabrication of new complexes which perform as a catalyst and chemotherapeutic drug is always a beneficial addition to the literature. Herein, we report three heterocyclic thiosemicarbazone-based Pd(II) complexes [Pd(HL1)Cl] (C1), [Pd(L2)(PPh3)] (C2) and [Pd(L3)(PPh3)]Cl (C3) having coligands Cl and PPh3. Thiosemicarbazone ligands (H2L1, H2L2 and HL3) and the complexes (C1-C3) were characterized methodically using several spectroscopic techniques. Single-crystal X-ray diffraction methods reveal that the structural environment around the metal center of C2 is square planar, while for C1 and C3 it is a slighty distorted square plane. The supramolecular network of compounds was built via hydrogen bonds, C-H⋯π and π⋯π interactions. Density functional theory (DFT) study of the structure of the complexes supports experimental findings. The application of these complexes as catalysts toward Suzuki-Miyaura coupling reactions has been examined with various aryl halides and phenyl boronic acid in PEG 400 solvent. The complexes displayed good biomolecular interactions with DNA/protein, with a binding constant value of the order of 105 M-1. C3 showed greater binding efficacy toward these biomolecules than the other complexes, which might be due to the cationic nature of C3. Furthermore, antitumor activity of the complexes was studied against the human triple-negative breast cancer (TNBC) cell line MDA-MB-231. It was found that C3 was more toxic (IC50 = 10 ± 2.90 μM) toward MDA-MB-231 cells than the other complexes. A known chemotherapeutic drug, 5-fluorouracil, was included as positive control. The programmed cell death mechanism of C3 was confirmed. Additionally, complex-induced apoptosis was confirmed and occurred via a mitochondria-dependent (intrinsic) pathway.

Malignant melanoma in Portuguese adult population: a scoping review of the real-world evidence

PURPOSE

Malignant melanoma is an aggressive cancer, and there is a notable dearth on epidemiology, clinical and treatment characterization within the Portuguese population. We performed a scoping review to identify real-world evidence studies focused in Portuguese adult patients with malignant melanoma.

METHODS

A comprehensive search was conducted. After screening, we described the studies by design, sample size, geographics, setting, population, and outcomes reported.

RESULTS

The search yielded 54 studies, mainly retrospective (79.6%). The population assessed was heterogeneous varying from patients with melanoma in general to specific types of melanoma, or even more restricted to patients with specific conditions. The evidence found was mostly concerning clinical outcomes (n=46), patients' clinical profile (n=44) and demographic characterization (n=48). Treatment information was described in 30 studies whereas only 18 reported epidemiological parameters. Studies were mainly performed by the major oncology centers in Lisbon, Oporto and Coimbra, and only two evaluated the entire Portuguese population. To allow comparability, only studies including patients with cutaneous malignant melanoma were considered (13 of the 54) for outcomes evaluation analysis. Median OS varied from 18 to 36 months, assessed after melanoma treatment. Incidence was the most reported epidemiological parameter, confirming the increasing number of cutaneous malignant melanoma patients over the years. Only one study reported prevalence and four reported mortality rates.

CONCLUSIONS

The evidence found confirms the lack of information about malignant melanoma in Portugal, highlighting the need of real-world studies to assess melanoma prevalence and incidence rates, current treatment approaches, and clinical characterization of these patients.

Dermoscopy Education for Plastic Surgery Residents: How a Brief Theoretical Course and Practical Training Have an Impact

Background

Currently, the evaluation of pigmented skin lesions relies on dermoscopy, which has become the standard of care. As melanoma is one of the principal areas of expertise in plastic surgery, it is essential that diagnostic skills be acquired during the course of specialization. This study aimed to assess the impact and effectiveness of a brief and intensive dermoscopy training program for plastic surgery residents.

Methods

This study was carried out on a group of 41 doctors, who were divided into three categories based on their experience in dermoscopy (none, intermediate, and advanced). A preliminary assessment of each participant's baseline knowledge was conducted by using a 15-query test. Subsequently, the participants attended a 90-minute lecture on diagnostic techniques and the process of differentiating between various skin lesions. To determine the effectiveness of the lecture in improving diagnostic skills, the participants were tested immediately after the lecture and again after a 3-month period.

Results

At the conclusion of the final examination, all three groups achieved an accuracy rate of at least 80% for dermatoscopic diagnosis. However, none of the groups was completely successful. The variations in diagnostic accuracy among the three groups are presented, and P values were calculated for each group.

Conclusion

The short, intensive course of dermoscopy has proven to have a significant positive impact on plastic surgeons in their postdegree training program.

Encapsulation of a small-molecule drug based on substituted 2-aminothiophenes in calcium carbonate carriers for therapy of melanoma

Although small molecule drugs are widely used in chemotherapy, their low bioavailability, low-concentrated dose in the tumor zone, systemic toxicity, and chemoresistance can significantly limit the therapeutic outcome. These drawbacks can be overcome by two main strategies: (i) development of novel therapeutic molecules with more significant antitumor activity than currently available drugs and (ii) loading chemotherapeutic agents into drug delivery systems. In this study, we aimed to encapsulate a highly prospective small molecule drug based on substituted 2-aminothiophene (2-AT) into calcium carbonate (CaCO3) microparticles (MPs) for the treatment of melanoma tumors. In particular, we have optimized the encapsulation of 2-AT into MPs (2-AT@MPs), studied drug release efficiency, investigated cellular uptake, and evaluated in vivo biodistribution and tumor inhibition efficiency. In vitro results revealed that 2-AT@MPs were able to penetrate into tumor spheroids, leading to prolonged release of 2-AT. By performing intratumoral injection of 2-AT@MPs we observed significant melanoma suppressions in murine models: ∼0.084 cm3 for 2-AT@MPs at a dose of 0.4 g kg-1versus ∼1.370 cm3 for untreated mice. In addition, the 2-AT@MPs showed negligible in vivo toxicity towards major organs such as heart, lung, liver, kidney, and spleen. Thus, this work provided an efficient strategy for the improved chemotherapy of solid tumors by using an encapsulated form of small molecule drugs.

ACSS2 enables melanoma cell survival and tumor metastasis by negatively regulating the Hippo pathway

Introduction

Acetyl-CoA synthetase 2 (ACSS2), one of the enzymes that catalyze the conversion of acetate to acetyl-CoA, has been proved to be an oncogene in various cancers. However, the function of ACSS2 is still largely a black box in melanoma.

Methods

The ACSS2 expression was detected in melanoma cells and melanocytes at both protein and mRNA levels. Cell viability, apoptosis, migration and invasion were investigated after ACSS2 knockdown. RNA sequencing (RNA-Seq) technology was employed to identify differentially expressed genes caused by ACSS2 knockdown, which were then verified by immunoblotting analysis. Animal experiments were further performed to investigate the influence of ACSS2 on tumor growth and metastasis in vivo.

Results

Firstly, we found that ACSS2 was upregulated in most melanoma cell lines compared with melanocytes. In addition, ACSS2 knockdown dramatically suppressed melanoma cell migration and invasion, whereas promoted cell apoptosis in response to endoplasmic reticulum (ER) stress. Furthermore, tumor growth and metastasis were dramatically suppressed by ACSS2 knockdown in vivo. RNA-Seq suggested that the Hippo pathway was activated by ACSS2 knockdown, which was forwardly confirmed by Western blotting and rescue experiments. Taken together, we demonstrated that ACSS2 enables melanoma cell survival and tumor metastasis via the regulation of the Hippo pathway.

Discussion

In summary, this study demonstrated that ACSS2 may promote the growth and metastasis of melanoma by negatively regulating the Hippo pathway. Targeting ACSS2 may be a promising target for melanoma treatment.

Cyclodextrin encapsulation enabling the anticancer repositioning of disulfiram: Preparation, analytical and in vitro biological characterization of the inclusion complexes

Drug repositioning is a high-priority and feasible strategy in the field of oncology research, where the unmet medical needs are continuously unbalanced. Disulfiram is a potential non-chemotherapeutic, adjuvant anticancer agent. However, the clinical translation is limited by the drug's poor bioavailability. Therefore, the molecular encapsulation of disulfiram with cyclodextrins is evaluated to enhance the solubility and stability of the drug. The present work describes for the first time the complexation of disulfiram with randomly methylated-β-cyclodextrin. A parallel analytical andin vitrobiological comparison of disulfiram inclusion complexes with hydroxypropyl-β-cyclodextrin, randomly methylated-β-cyclodextrin and sulfobutylether-β-cyclodextrin is conducted. A significant drug solubility enhancement by about 1000-folds and fast dissolution in 1 min is demonstrated. Thein vitrodissolution-permeation studies and proliferation assays demonstrate the solubility-dependent efficacy of the drug. Throughout the different cancer cell lines' characteristics and disulfiram unspecific antitumoral activity, the inhibitory efficacy of the cyclodextrin encapsulated drug on melanoma (IC50 about 100 nM) and on glioblastoma (IC50 about 7000 nM) cell lines differ by a magnitude. This pre-formulation screening experiment serves as a proof of concept of using cyclodextrin encapsulation as a platform tool for further drug delivery development in repositioning areas.

Silver Complexes of Miconazole and Metronidazole: Potential Candidates for Melanoma Treatment

Melanoma, arguably the deadliest form of skin cancer, is responsible for the majority of skin-cancer-related fatalities. Innovative strategies concentrate on new therapies that avoid the undesirable effects of pharmacological or medical treatment. This article discusses the chemical structures of [(MTZ)2AgNO3], [(MTZ)2Ag]2SO4, [Ag(MCZ)2NO3], [Ag(MCZ)2BF4], [Ag(MCZ)2SbF6] and [Ag(MCZ)2ClO4] (MTZ-metronidazole; MCZ-miconazole) silver(I) compounds and the possible relationship between the molecules and their cytostatic activity against melanoma cells. Molecular Hirshfeld surface analysis and computational methods were used to examine the possible association between the structure and anticancer activity of the silver(I) complexes and compare the cytotoxicity of the silver(I) complexes of metronidazole and miconazole with that of silver(I) nitrate, cisplatin, metronidazole and miconazole complexes against A375 and BJ cells. Additionally, these preliminary biological studies found the greatest IC50 values against the A375 line were demonstrated by [Ag(MCZ)2NO3] and [(MTZ)2AgNO3]. The compound [(MTZ)2AgNO3] was three-fold more toxic to the A375 cells than the reference (cisplatin) and 15 times more cytotoxic against the A375 cells than the normal BJ cells. Complexes of metronidazole with Ag(I) are considered biocompatible at a concentration below 50 µmol/L.

Explainable AI-driven model for gastrointestinal cancer classification

Although the detection procedure has been shown to be highly effective, there are several obstacles to overcome in the usage of AI-assisted cancer cell detection in clinical settings. These issues stem mostly from the failure to identify the underlying processes. Because AI-assisted diagnosis does not offer a clear decision-making process, doctors are dubious about it. In this instance, the advent of Explainable Artificial Intelligence (XAI), which offers explanations for prediction models, solves the AI black box issue. The SHapley Additive exPlanations (SHAP) approach, which results in the interpretation of model predictions, is the main emphasis of this work. The intermediate layer in this study was a hybrid model made up of three Convolutional Neural Networks (CNNs) (InceptionV3, InceptionResNetV2, and VGG16) that combined their predictions. The KvasirV2 dataset, which comprises pathological symptoms associated to cancer, was used to train the model. Our combined model yielded an accuracy of 93.17% and an F1 score of 97%. After training the combined model, we use SHAP to analyze images from these three groups to provide an explanation of the decision that affects the model prediction.

Trends in Melanoma Mortality in Serbia: A 22-Year Population-Based Study

Background

We aimed to investigating the sex-specific and age-specific melanoma mortality trends observed on the territory of Serbia between 2000 and 2021.

Methods

This population-based study used data from the Statistical Office of the Republic of Serbia database during the period 2000-2021. The calculation of the gender and age-standardized rates (ASR) was performed. We used a regression analysis complete with linear trend model.

Results

The mean ASR was 1.77 per 100,000 people, meaning that male mortality rates (2.24 per 100,000) was higher than female mortality rates (1.34 per 100,000). During the observation period, a rising trend in mortality from melanoma skin cancer was reported. Observed by gender, the change of melanoma mortality trend was significant in men (P=0.021), but not in women (P=0.747). The annual growth rate of ASRs values was 1.43%. A increase in the melanoma mortality rate was observed since 2000 by 2.44% annually in males and by 2.79% annually in females. Mortality rates were increasing in both sexes as they aged, and the greatest number of deaths was recorded in the group of those aged 80 yr or above (16.25 per 100,000 for men; 10.45 per 100,000 for women).

Conclusion

Our study findings underline the importance of launching more effective public health awareness campaigns to educate people about the dangers of melanoma and its symptoms' detection along with establishing a diagnosis at an early stage of the disease, especially among male patients and those at an advanced age.

Molecular and functional anticancer effects of GLP/G9a inhibition by UNC0646 in MeWo melanoma cells

In recent years, histone methyltransferases (HMTs) have emerged as important therapeutic targets in cancer due to their oncogenic role. Herein, we used the GLP/G9a inhibitor UNC0646 to assess whether the inhibition of such HMTs could induce cell death in MeWo melanoma cells. Furthermore, we investigated the cellular and molecular mechanisms involved in the observed cell death events. Finally, we performed a functional genomics analysis of 480 melanoma samples to characterize G9a/GLP involvement in melanoma. Interestingly, after UNC0646 treatment, MeWo cells underwent apoptosis, followed by loss of mitochondrial membrane potential and the generation of reactive oxygen species (ROS). Furthermore, MeWo cells treated with UNC0646 showed cell cycle arrest and inhibition of proliferation. At the molecular level, UNC0646 treatment increased the transcriptional levels of CDK1 and BAX, and decreased BCL-2 mRNA levels. Finally, we performed a functional enrichment analysis, which demonstrated that dozens of biological pathways were enriched in melanoma samples according to GLP and G9a expression, including apoptosis and necrosis. Taken together, our data show that inhibition of GLP/G9a using UNC0646 exerts anticancer effects on melanoma cells by controlling their proliferation and inducing apoptosis.

Assessment of RAS-RAF-MAPK Pathway Mutation Status in Healthy Skin, Benign Nevi, and Cutaneous Melanomas: Pilot Study Using Droplet Digital PCR

In the present study, we employed the ddPCR and IHC techniques to assess the prevalence and roles of RAS and RAF mutations in a small batch of melanoma (n = 22), benign moles (n = 15), and normal skin samples (n = 15). Mutational screening revealed the coexistence of BRAF and NRAS mutations in melanomas and nevi and the occurrence of NRAS G12/G13 variants in healthy skin. All investigated nevi had driver mutations in the BRAF or NRAS genes and elevated p16 protein expression, indicating cell cycle arrest despite an increased mutational burden. BRAF V600 mutations were identified in 54% of melanomas, and NRAS G12/G13 mutations in 50%. The BRAF mutations were associated with the Breslow index (BI) (p = 0.029) and TIL infiltration (p = 0.027), whereas the NRAS mutations correlated with the BI (p = 0.01) and the mitotic index (p = 0.04). Here, we demonstrate that the "young" ddPCR technology is as effective as a CE-IVD marked real-time PCR method for detecting BRAF V600 hotspot mutations in tumor biopsies and recommend it for extended use in clinical settings. Moreover, ddPCR was able to detect low-frequency hotspot mutations, such as NRAS G12/G13, in our tissue specimens, which makes it a promising tool for investigating the mutational landscape of sun-damaged skin, benign nevi, and melanomas in more extensive clinical studies.

Melanoma biology and treatment: a review of novel regulated cell death-based approaches

The incidence of melanoma, the most lethal form of skin cancer, has increased due to ultraviolet exposure. The treatment of advanced melanoma, particularly metastatic cases, remains challenging with poor outcomes. Targeted therapies involving BRAF/MEK inhibitors and immunotherapy based on anti-PD1/anti-CTLA4 antibodies have achieved long-term survival rates of approximately 50% for patients with advanced melanoma. However, therapy resistance and inadequate treatment response continue to hinder further breakthroughs in treatments that increase survival rates. This review provides an introduction to the molecular-level pathogenesis of melanoma and offers an overview of current treatment options and their limitations. Cells can die by either accidental or regulated cell death (RCD). RCD is an orderly cell death controlled by a variety of macromolecules to maintain the stability of the internal environment. Since the uncontrolled proliferation of tumor cells requires evasion of RCD programs, inducing the RCD of melanoma cells may be a treatment strategy. This review summarizes studies on various types of nonapoptotic RCDs, such as autophagy-dependent cell death, necroptosis, ferroptosis, pyroptosis, and the recently discovered cuproptosis, in the context of melanoma. The relationships between these RCDs and melanoma are examined, and the interplay between these RCDs and immunotherapy or targeted therapy in patients with melanoma is discussed. Given the findings demonstrating melanoma cell death in response to different stimuli associated with these RCDs, the induction of RCD shows promise as an integral component of treatment strategies for melanoma.

A Narrative Review of Current Knowledge on Cutaneous Melanoma

Cutaneous melanoma is a public health problem. Efforts to reduce its incidence have failed, as it continues to increase. In recent years, many risk factors have been identified. Numerous diagnostic systems exist that greatly assist in early clinical diagnosis. The histopathological aspect illustrates the grim nature of these cancers. Currently, pathogenic pathways and the tumor microclimate are key to the development of therapeutic methods. Revolutionary therapies like targeted therapy and immune checkpoint inhibitors are starting to replace traditional therapeutic methods. Targeted therapy aims at a specific molecule in the pathogenic chain to block it, stopping cell growth and dissemination. The main function of immune checkpoint inhibitors is to boost cellular immunity in order to combat cancer cells. Unfortunately, these therapies have different rates of effectiveness and side effects, and cannot be applied to all patients. These shortcomings are the basis of increased incidence and mortality rates. This study covers all stages of the evolutionary sequence of melanoma. With all these data in front of us, we see the need for new research efforts directed at therapies that will bring greater benefits in terms of patient survival and prognosis, with fewer adverse effects.

Revisiting the Role of B-RAF Kinase as a Therapeutic Target in Melanoma

Malignant melanoma is the rarest but most aggressive and deadly skin cancer. Melanoma is the result of a malignant transformation of melanocytes, which leads to their uncontrolled proliferation. Mutations in the mitogen-activated protein kinase (MAPK) pathway, which are crucial for the control of cellular processes, such as apoptosis, division, growth, differentiation, and migration, are one of its most common causes. BRAF kinase, as one of the known targets of this pathway, has been known for many years as a prominent molecular target in melanoma therapy, and the following mini-review outlines the state-of-the-art knowledge regarding its structure, mutations and mechanisms.

A Review of Advanced Cutaneous Melanoma Therapies and Their Mechanisms, from Immunotherapies to Lysine Histone Methyl Transferase Inhibitors

Advanced cutaneous melanoma is considered to be the most aggressive type of skin cancer and has variable rates of treatment response. Currently, there are some classes of immunotherapy and target therapies for its treatment. Immunotherapy can inhibit tumor growth and its recurrence by triggering the host's immune system, whereas targeted therapy inhibits specific molecules or signaling pathways. However, melanoma responses to these treatments are highly heterogeneous, and patients can develop resistance. Epigenomics (DNA/histone modifications) contribute to cancer initiation and progression. Epigenetic alterations are divided into four levels of gene expression regulation: DNA methylation, histone modification, chromatin remodeling, and non-coding RNA regulation. Deregulation of lysine methyltransferase enzymes is associated with tumor initiation, invasion, development of metastases, changes in the immune microenvironment, and drug resistance. The study of lysine histone methyltransferase (KMT) and nicotinamide N-methyltransferase (NNMT) inhibitors is important for understanding cancer epigenetic mechanisms and biological processes. In addition to immunotherapy and target therapy, the research and development of KMT and NNMT inhibitors is ongoing. Many studies are exploring the therapeutic implications and possible side effects of these compounds, in addition to their adjuvant potential to the approved current therapies. Importantly, as with any drug development, safety, efficacy, and specificity are crucial considerations when developing methyltransferase inhibitors for clinical applications. Thus, this review article presents the recently available therapies and those in development for advanced cutaneous melanoma therapy.

Oxymatrine inhibits melanoma development by modulating the immune microenvironment and targeting the MYC/PD-L1 pathway

Oxymatrine, also known as ammothamnine or oxysophoridine, is a natural compound isolated from Sophora flavescens (in Chinese, Kushen), and many previous researchers have characterized its anti-inflammatory, anti-fibrotic and anti-tumor properties. However, the underlying anti-tumor immunological mechanism of oxymatrine remains elusive. In this study, we carried out experiments both in vitro and in vivo and investigated the anti-tumor effect of oxymatrine to inhibit the proliferation and migration of melanoma B16 cells, while promoting apoptosis. Oxymatrine upregulated CD4+ T, CD8+ T and NKT cells, downregulated Treg cells, promoted TNF-α secretion, and successfully modulated the immune microenvironment and ultimately suppressed melanoma development in subcutaneous tumor models established in mice. Evidence from network pharmacology and RNAseq suggested that possible targets of oxymatrine for melanoma treatment included PD-L1 and MYC. We observed oxymatrine inhibited PD-L1 and MYC expression in melanoma cells via qRT-PCR and western blotting analysis, and found MYC potentially regulated PD-L1 to mediate anti-tumor effects. These findings provide insight into the mechanism by which oxymatrine inhibits melanoma and enhances the anti-tumor immune effect. In summary, our study proposes a novel approach to suppress melanoma by targeting the MYC/PD-L1 pathway using oxymatrine, which may develop into a less toxic and more efficient anti-tumor agent for melanoma treatment.

Chemical Composition, In Vitro Antitumor Effect, and Toxicity in Zebrafish of the Essential Oil from Conyza bonariensis (L.) Cronquist (Asteraceae)

The essential oil from Conyza bonariensis (Asteraceae) aerial parts (CBEO) was extracted by hydrodistillation in a Clevenger-type apparatus and was characterized by gas chromatography-mass spectrometry. The antitumor potential was evaluated against human tumor cell lines (melanoma, cervical, colorectal, and leukemias), as well as non-tumor keratinocyte lines using the MTT assay. The effect of CBEO on the production of Reactive Oxygen Species (ROS) was evaluated by DCFH-DA assay, and a protection assay using the antioxidant N-acetyl-L-cysteine (NAC) was also performed. Moreover, the CBEO toxicity in the zebrafish model was assessed. The majority of the CBEO compound was (Z)-2-lachnophyllum ester (57.24%). The CBEO exhibited selectivity towards SK-MEL-28 melanoma cells (half maximal inhibitory concentration, IC50 = 18.65 ± 1.16 µg/mL), and induced a significant increase in ROS production. In addition, the CBEO's cytotoxicity against SK-MEL-28 cells was reduced after pretreatment with NAC. Furthermore, after 96 h of exposure, 1.5 µg/mL CBEO induced death of all zebrafish embryos. Non-lethal effects were observed after exposure to 0.50-1.25 µg/mL CBEO. Additionally, significant alterations in the activity of enzymes associated with oxidative stress in zebrafish larvae were observed. These results provide evidence that CBEO has a significant in vitro antimelanoma effect by increasing ROS production and moderate embryotoxicity in zebrafish.

Exploring the Complex and Multifaceted Interplay between Melanoma Cells and the Tumor Microenvironment

Malignant melanoma is a very aggressive skin cancer, characterized by a heterogeneous nature and high metastatic potential. The incidence of melanoma is continuously increasing worldwide, and it is one of the most common cancers in young adults. In the past twenty years, our understanding of melanoma biology has increased profoundly, and disease management for patients with disseminated disease has improved due to the emergence of immunotherapy and targeted therapy. However, a significant fraction of patients relapse or do not respond adequately to treatment. This can partly be explained by the complex signaling between the tumor and its microenvironment, giving rise to melanoma phenotypes with different patterns of disease progression. This review focuses on the key aspects and complex relationship between pathogenesis, genetic abnormalities, tumor microenvironment, cellular plasticity, and metabolic reprogramming in melanoma. By acquiring a deeper understanding of the multifaceted features of melanomagenesis, we can reach a point of more individualized and patient-centered disease management and reduced costs of ineffective treatments.

β-Arrestins: Structure, Function, Physiology, and Pharmacological Perspectives

The two β-arrestins, β-arrestin-1 and -2 (systematic names: arrestin-2 and -3, respectively), are multifunctional intracellular proteins that regulate the activity of a very large number of cellular signaling pathways and physiologic functions. The two proteins were discovered for their ability to disrupt signaling via G protein-coupled receptors (GPCRs) via binding to the activated receptors. However, it is now well recognized that both β-arrestins can also act as direct modulators of numerous cellular processes via either GPCR-dependent or -independent mechanisms. Recent structural, biophysical, and biochemical studies have provided novel insights into how β-arrestins bind to activated GPCRs and downstream effector proteins. Studies with β-arrestin mutant mice have identified numerous physiologic and pathophysiological processes regulated by β-arrestin-1 and/or -2. Following a short summary of recent structural studies, this review primarily focuses on β-arrestin-regulated physiologic functions, with particular focus on the central nervous system and the roles of β-arrestins in carcinogenesis and key metabolic processes including the maintenance of glucose and energy homeostasis. This review also highlights potential therapeutic implications of these studies and discusses strategies that could prove useful for targeting specific β-arrestin-regulated signaling pathways for therapeutic purposes. SIGNIFICANCE STATEMENT: The two β-arrestins, structurally closely related intracellular proteins that are evolutionarily highly conserved, have emerged as multifunctional proteins able to regulate a vast array of cellular and physiological functions. The outcome of studies with β-arrestin mutant mice and cultured cells, complemented by novel insights into β-arrestin structure and function, should pave the way for the development of novel classes of therapeutically useful drugs capable of regulating specific β-arrestin functions.

Real-World Evaluation of the Management, Treatment Pathways and Outcome of Melanoma Patients with Target Therapies in Italy

INTRODUCTION

In recent years, an increasing trend in the incidence of melanoma has been observed in Europe. Although early diagnosis and prompt intervention with local resection often results in positive outcomes, conversely, metastatic disease is still clinically challenging with a poor prognosis and a 5-year survival of around 30%. The growing awareness of melanoma biology and of antitumor immune responses has allowed the development of novel therapies targeted at specific molecular alterations occurring at advanced stages. This real-world analysis examined patients with melanoma in Italy, focusing on treatment patterns, outcome, time to discontinuation (TTD), and resource consumption.

METHODS

Two retrospective observational analyses were conducted for BRAF+ patients with metastatic melanoma and those with a positive sentinel lymph node biopsy in an adjuvant setting, retrieving data from the administrative databases covering 13.3 million residents. The cohort melanoma BRAF+ in metastatic setting comprised 729 patients with targeted therapy (TT) (n = 671 with TT as first line and 79 as second line).

RESULTS

Median TTD was 10.6 months in first line and 8.1 months in second line. Median overall survival from the start of first TT line was 27 months and was 11.8 months for patients with brain metastasis. In the dabrafenib plus trametinib patients, main healthcare resource consumption tended to increase in the presence of brain metastasis. The cohort with a positive sentinel lymph node biopsy under adjuvant therapy (n = 289) included 8% patients treated with dabrafenib plus trametinib or tested BRAF+, 5% BRAF wild-type, and 10% under immunotherapy.

CONCLUSION

Our findings provided an overview on TT utilization on metastatic melanoma patients in real clinical practice and highlighted an increased burden in brain metastatic patients.

Current Treatment of Melanoma Brain Metastases

Melanoma is a type of skin cancer in which there is a strong correlation between its occurrence and exposure to ultraviolet radiation. Although it is not the most common skin cancer, it has the highest mortality rate of all skin cancers. The prognosis of patients is significantly worsened by melanoma metastasis to the brain, which often occurs in patients with advanced disease. The formation and development of melanoma metastases to the brain involve a very complex process, and their mechanisms are not fully understood. One of the ways for metastatic melanoma cells to survive and develop cancer in the brain environment is the presence of oncogenic BRAF mutation, which occurs in up to 50% of metastatic melanoma cases. Before discovering new methods of treating metastases, the overall survival of patients with this disease was 6 months. Currently, research is being conducted on new drugs using immunotherapy (immune checkpoint inhibitors: anti-PD-1, anti-CTLA-4) and targeted therapy (BRAF and MEK inhibitors) to improve the prognosis of patients. In this article, we summarize the current state of knowledge about the results of treating brain metastases with new systemic therapies.

Efficacy and Safety of Rechallenge with BRAF/MEK Inhibitors in Advanced Melanoma Patients: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis aims to evaluate the efficacy and safety of rechallenging advanced melanoma patients with BRAFi/MEKi. Seven studies, accounting for 400 patients, were included. Most patients received immunotherapy before the rechallenge, and 79% underwent rechallenge with the combination of BRAFi/MEKi. We found a median progression-free survival of 5 months and overall survival of 9.8 months. The one-year survival rate was 42.63%. Regarding response, ORR was 34% and DCR 65%. There were no new or unexpected safety concerns. Rechallenge with BRAFi/MEKi can improve outcomes in advanced melanoma patients with refractory disease. These findings have significant implications for clinical practice, particularly in the setting of progressive disease in later lines and limited treatment options.

Cu(II) and Zn(II) Complexes of New 8-Hydroxyquinoline Schiff Bases: Investigating Their Structure, Solution Speciation, and Anticancer Potential

We report the synthesis and characterization of three novel Schiff bases (L1-L3) derived from the condensation of 2-carbaldehyde-8-hydroxyquinoline with amines containing morpholine or piperidine moieties. These were reacted with CuCl₂ and ZnCl₂ yielding six new coordination compounds, with the general formula ML₂, where M = Cu(II) or Zn(II) and L = L1-L3, which were all characterized by analytical, spectroscopic (Fourier transform infrared (FTIR), UV-visible absorption, nuclear magnetic resonance (NMR), or electron paramagnetic resonance (EPR)), and mass spectrometric techniques, as well as by single-crystal X-ray diffraction. In the solid state, two Cu(II) complexes, with L1 and L2, are obtained as dinuclear compounds, with relatively short Cu-Cu distances (3.146 and 3.171 Å for Cu₂(L1)₄ and Cu₂(L2)₄, respectively). The free ligands show moderate lipophilicity, while their complexes are more lipophilic. The pK_a values of L1-L3 and formation constants of the complex (for ML and ML₂) species were determined by spectrophotometric titrations, with the Cu(II) complexes showing higher stability than the Zn(II) complexes. EPR indicated the presence of several species in solution as pH varied and binding modes were proposed. The binding of the complexes to bovine serum albumin (BSA) was evaluated by fluorescence and circular dichroism (CD) spectroscopies. All complexes bind BSA, and as demonstrated by CD, the process takes several hours to reach equilibrium. The antiproliferative activity was evaluated in malignant melanoma cells (A375) and in noncancerous keratinocytes (HaCaT). All complexes display significant cytotoxicity (IC₅₀ < 10 μM) but modest selectivity. The complexes show higher activity than the free ligands, the Cu(II) complexes being more active than the Zn(II) complexes, and approximately twice more cytotoxic than cisplatin. A Guava ViaCount assay corroborated the antiproliferative activity.

Novel Hydrogenated Derivatives of Chemically Modified Curcumin CMC2.24 Are Potent Inhibitors of Melanogenesis in an In Vitro Model: Influence of Degree of Hydrogenation

Chemically modified curcumin, CMC2.24, is a promising therapeutic that has shown efficacy in ameliorating excessive pigmentation in our previous studies. However, its inherent disadvantages of color, stability, solubility, and cytotoxicity to melanocytes and keratinocytes at concentrations > 4 µg/mL posed challenges in its use in cosmetic formulations. To overcome these limitations, chemical reduction by hydrogenation of CMC2.24 (compound 1) was developed to yield products at different time points of hydrogenation (1 h, 2 h, 4 h, and 24 h) referred to as partially (2, 3, 4) or fully hydrogenated (5) products, and the effects of the degree of hydrogenation on melanogenesis in vitro were explored. Compound 1 and products 2-5 were evaluated using mushroom tyrosinase activity assays with two substrates (L-tyrosine and L-DOPA), then cellular assays using B16F10 mouse melanoma cells, MNT-1 human melanoma cells, and physiological normal human melanocytes (HEMn-DP cells). The cytotoxicity, melanin contents, cellular tyrosinase activities, and cellular oxidative stress were evaluated. Moreover, the recovery of melanin contents in HEMn-DP cells was also studied. Our results provide novel insights into the role of the degree of hydrogenation of compound 1 on the biological effects of melanogenesis, which were dependent on cell type. To the best of our knowledge, this is the first study to show that in HEMn-DP cells, the anti-melanogenic efficacy of the yellow-colored CMC2.24 is retained as early as 1 h after its hydrogenation; this efficacy is enhanced with longer durations of hydrogenation, with a robust efficacy achieved for the 24 h hydrogenated product 5 at the lowest concentration of 4 µg/mL. A similar potency could be achieved for product 4 at higher concentrations, although interestingly, both differ only by a minor amount of dihydro-CMC2.24. Our results indicate promise for using products 4 & 5 as a skin-lightener in cosmetic formulations with the advantages of lack of color combined with a potency much greater than that of the parent compound 1 at lower concentrations and reversibility of the effects on melanocytes. This, along with the easy synthesis and scale-up of the hydrogenation method for CMC2.24 and the documented higher solubility, stability, and bioavailability of tetrahydrocurcumin, provides further impetus to incorporating these derivatives in cosmetic formulations. The results of this study can help to extend the therapeutic window of the lead compound CMC2.24 by providing options for selecting partially or fully hydrogenated derivatives for cosmetic applications where a trade-off between color and efficacy is needed. Thus, the degree of hydrogenation can be tuned for desired biological effects. Further studies are warranted to evaluate the efficacy of products 4 & 5 at suppressing pigmentation in 3D skin-tissue equivalents and in vivo models.

Daphnetin, a Coumarin with Anticancer Potential against Human Melanoma: In Vitro Study of Its Effective Combination with Selected Cytostatic Drugs

(1) The treatment of metastatic or drug-resistant melanoma is still a significant therapeutic problem. The aim of this study was to evaluate the anticancer potential of daphnetin (7,8-dihydroxycoumarin) and its combinations with five different cytostatic drugs (mitoxantrone, docetaxel, vemurafenib, epirubicin and cisplatin). (2) The viability, proliferation and cytotoxicity of daphnetin against four human malignant melanoma cell lines were evaluated. The interactions were assessed using isobolographic analysis for the combinations of daphnetin with each of the five cytostatic drugs. (3) Daphnetin showed anticancer activity against malignant melanoma, with IC₅₀ values ranging from 40.48 ± 10.90 µM to 183.97 ± 18.82 µM, depending on the cell line. The combination of daphnetin with either vemurafenib or epirubicin showed an antagonistic interaction. Moreover, additive interactions were observed for the combinations of daphnetin with cisplatin and docetaxel. The most desirable synergistic interactions for human melanoma metastatic cell lines were observed for the combination of daphnetin with mitoxantrone. (4) The obtained results suggest that daphnetin should not be combined with vemurafenib or epirubicin in the treatment of malignant melanoma due to the abolition of their anticancer effects. The combination of daphnetin with mitoxantrone is beneficial in the treatment of metastatic melanoma due to their synergistic interaction.

Collagen Hydrolysate Effects on Photodynamic Efficiency of Gallium (III) Phthalocyanine on Pigmented Melanoma Cells

The conjugation of photosensitizer with collagen seems to be a very promising approach for innovative topical photodynamic therapy (PDT). The study aims to evaluate the effects of bovine collagen hydrolysate (Clg) on the properties of gallium (III) phthalocyanine (GaPc) on pigmented melanoma. The interaction of GaPc with Clg to form a conjugate (GaPc-Clg) showed a reduction of the intensive absorption Q-band (681 nm) with a blue shift of the maximum (678 nm) and a loss of shape of the UV-band (354 nm). The fluorescence of GaPc, with a strong emission peak at 694 nm was blue shifted due to the conjugation which lower intensity owing to reduce quantum yield (0.012 vs. 0.23, GaPc). The photo- and dark cytotoxicity of GaPc, Glg and GaPc-Clg on pigmented melanoma cells (SH-4) and two normal cell lines (BJ and HaCaT) showed a slight decrease of cytotoxicity for a conjugate, with low selectivity index (0.71 vs. 1.49 for GaPc). The present study suggests that the ability of collagen hydrolysate to form gels minimizes the high dark toxicity of GaPc. Collagen used for conjugation of a photosensitizer might be an essential step in advanced topical PDT.

BRAF V600-Mutated Metastatic Melanoma and Targeted Therapy Resistance: An Update of the Current Knowledge

Melanoma is the most common cause of death in skin cancer due to its high metastatic potential. While targeted therapies have improved the care of patients with metastatic melanoma harboring the BRAFV600E mutation, these treatments are associated with a high frequency of resistance. Resistance factors are related to cellular adaptation as well as to changes in the tumor microenvironment. At the cellular level, resistance involves mutations, overexpression, activation, or inhibition of effectors involved in cell signaling pathways such as MAPK, PI3K/AKT, MITF, and epigenetic factors (miRNAs). In addition, several components of the melanoma microenvironment, such as soluble factors, collagen, and stromal cells also play a crucial role in this resistance. In fact, extracellular matrix remodeling impacts the physical and chemical properties with changes in the stiffness and acidity, respectively of the microenvironment. The cellular and immune components of the stroma are also affected, including immune cells and CAF. The aim of this manuscript is to review the mechanisms responsible for resistance to targeted therapies in BRAFV600E-mutated metastatic melanoma.

Determination of Some Isoquinoline Alkaloids in Extracts Obtained from Selected Plants of the Ranunculaceae, Papaveraceae and Fumarioideae Families by Liquid Chromatography and In Vitro and In Vivo Investigations of Their Cytotoxic Activity

Alkaloids are heterocyclic bases with widespread occurrence in nature. Plants are rich and easily accessible sources of them. Most isoquinoline alkaloids have cytotoxic activity for different types of cancer, including malignant melanoma, the most aggressive type of skin cancer. The morbidity of melanoma has increased worldwide every year. For that reason, developing new candidates for anti-melanoma drugs is highly needed. The aim of this study was to investigate the alkaloid compositions of plant extracts obtained from Macleaya cordata root, stem and leaves, Pseudofumaria lutea root and herb, Lamprocapnos spectabilis root and herb, Fumaria officinalis whole plant, Thalictrum foetidum root and herb, and Meconopsis cambrica root and herb by HPLC-DAD and LC-MS/MS. For determination of cytotoxic properties, human malignant melanoma cell line A375, human Caucasian malignant melanoma cell line G-361, and human malignant melanoma cell line SK-MEL-3 were exposed in vitro to the tested plant extracts. Based on the in vitro experiments, Lamprocapnos spectabilis herb extract was selected for further, in vivo research. The toxicity of the extract obtained from Lamprocapnos spectabilis herb was tested using an animal zebrafish model in the fish embryo toxicity test (FET) for determination of the LC₅₀ value and non-toxic doses. Determination of the influence of the investigated extract on the number of cancer cells in a living organism was performed using a zebrafish xenograft model. Determination of the contents of selected alkaloids in different plant extracts was performed using high performance liquid chromatography (HPLC) in a reverse-phase system (RP) on a Polar RP column with a mobile phase containing acetonitrile, water and ionic liquid. The presence of these alkaloids in plant extracts was confirmed by LC-MS/MS. Preliminary cytotoxic activity of all prepared plant extracts and selected alkaloid standards was examined using human skin cancer cell lines A375, G-361, and SK-MEL-3. The cytotoxicity of the investigated extract was determined in vitro by cell viability assays (MTT). For in vivo determination of investigated extract cytotoxicity, a Danio rerio larvae xenograft model was used. All investigated plant extracts in in vitro experiments exhibited high cytotoxic activity against the tested cancer cell lines. The results obtained using the Danio rerio larvae xenograft model confirmed the anticancer activity of the extract obtained from Lamprocapnos spectabilis herb. The conducted research provides a basis for future investigations of these plant extracts for potential use in the treatment of malignant melanoma.

Photodynamic Activity of TMPyP4/TiO2 Complex under Blue Light in Human Melanoma Cells: Potential for Cancer-Selective Therapy

The combination of TiO₂ nanoparticles (NPs) and photosensitizers (PS) may offer significant advantages in photodynamic therapy (PDT) of melanoma, such as improved cell penetration, enhanced ROS production, and cancer selectivity. In this study, we aimed to investigate the photodynamic effect of 5,10,15,20-(Tetra-N-methyl-4-pyridyl)porphyrin tetratosylate (TMPyP4) complexes with TiO₂ NPs on human cutaneous melanoma cells by irradiation with 1 mW/cm² blue light. The porphyrin conjugation with the NPs was analyzed by absorption and FTIR spectroscopy. The morphological characterization of the complexes was performed by Scanning Electron Microscopy and Dynamic Light Scattering. The singlet oxygen generation was analyzed by phosphorescence at 1270 nm. Our predictions indicated that the non-irradiated investigated porphyrin has a low degree of toxicity. The photodynamic activity of the TMPyP4/TiO₂ complex was assessed on the human melanoma Mel-Juso cell line and non-tumor skin CCD-1070Sk cell line treated with various concentrations of the PS and subjected to dark conditions and visible light-irradiation. The tested complexes of TiO₂ NPs with TMPyP4 presented cytotoxicity only after activation by blue light (405 nm) mediated by the intracellular production of ROS in a dose-dependent manner. The photodynamic effect observed in this evaluation was higher in melanoma cells than the effect observed in the non-tumor cell line, demonstrating a promising potential for cancer-selectivity in PDT of melanoma.

PRIMARY MULTIPLE MALIGNANT SKIN TUMORS: MELANOMA AND BASAL CELL CARCINOMA

The incidence of skin melanoma in the world is growing every year. Despite advances in diagnostics, the identification of the primary focus of melanoma in some cases is still difficult. The natural course sometimes manifests only with the appearance of melanoma metastases, which can mimic other diseases. Patient S., 52 years old, was admitted to the FCBRN of FMBA of Russia with complaints on periodic systemic dizziness, headaches of a pressing nature, episodes of speech impairment over the past three months. According to the brain MRI-scan results, a volumetric formation of the left frontal lobe was revealed. Upon examination, two non-pigmented lesions were found on the skin of the scalp and forehead. Due to the presence of focal neurological symptoms, it was decided to remove the brain tumor using neurophysiological monitoring and the scalp skin lesion, with histological verification. Morphological diagnosis of the removed brain tumor was a metastasis of amelanotic epithelioid melanoma. The skin lesion was basal cell carcinoma. Thus, the patient had primarily multiple malignant tumors: metastatic melanoma and basal cell carcinoma. The primary focus of melanoma could not be identified by available noninvasive research methods. The patient was referred to an oncologist to decide on the tactics of further examination and treatment. To date, the patient has been treated according to the scheme sh0876 1 line 1 course of pembrolizumab 400mg IV, cycle 42 days.

Combined Radiomodifying Effect of Fucoidan from the Brown Alga Saccharina cichorioides and Pacificusoside D from the Starfish Solaster pacificus in the Model of 3D Melanoma Cells

Cancer is one of the main causes of human mortality worldwide. Despite the advances in the diagnostics, surgery, radiotherapy, and chemotherapy, the search for more effective treatment regimens and drug combinations are relevant. This work aimed to assess the radiomodifying effect and molecular mechanism of action of fucoidan from the brown alga Saccharina cichorioides (ScF) and product of its autohydrolysis (ScF_AH) in combination with pacificusoside D from the starfish Solaster pacificus (SpD) on the model of viability and invasion of three-dimension (3D) human melanoma cells SK-MEL-2. The cytotoxicity of ScF (IC50 JB6 Cl41 > 800 µg/mL; IC50 SK-MEL-2 = 685.7 µg/mL), ScF_AH (IC50 JB6 Cl41/SK-MEL-2 > 800 µg/mL), SpD (IC50 JB6 Cl41 = 22 µM; IC50 SK-MEL-2 = 5.5 µM), and X-ray (ID50 JB6 Cl41 = 11.7 Gy; ID50 SK-MEL-2 = 6.7 Gy) was determined using MTS assay. The efficiency of two-component treatment of 3D SK-MEL-2 cells was revealed for ScF in combination with SpD or X-ray but not for the combination of fucoidan derivative ScF_AH with SpD or X-ray. The pre-treatment of spheroids with ScF, followed by cell irradiation with X-ray and treatment with SpD (three-component treatment) at low non-toxic concentrations, led to significant inhibition of the spheroids' viability and invasion and appeared to be the most effective therapeutic scheme for SK-MEL-2 cells. The molecular mechanism of radiomodifying effect of ScF with SpD was associated with the activation of the initiator and effector caspases, which in turn caused the DNA degradation in SK-MEL-2 cells as determined by the Western blotting and DNA comet assays. Thus, the combination of fucoidan from brown algae and triterpene glycoside from starfish with radiotherapy might contribute to the development of highly effective method for melanoma therapy.