The Challenging Melanoma Landscape: From Early Drug Discovery to Clinical Approval

Iodinated 4,4'-Bipyridines with Antiproliferative Activity Against Melanoma Cell Lines

In the last decade, biological processes involving halogen bond (HaB) as a leading interaction attracted great interest. However, although bound iodine atoms are considered powerful HaB donors, few iodinated new drugs were reported so far. Recently, iodinated 4,4'-bipyridines showed interesting properties as HaB donors in solution and in the solid state. In this paper, a study on the inhibition activity of seven halogenated 4,4'-bipyridines against malignant melanoma (MM) cell proliferation is described. Explorative dose/response proliferation assays were first performed with three 4,4'-bipyridines by using four MM cell lines and the normal BJ fibroblast cell line as control. Among them, the A375 MM cell line was the most sensitive, as determined by MTT assays, which was selected to evaluate the antiproliferative activity of all 4,4'-bipyridines. Significantly, the presence of an electrophilic iodine impacted the biological activity of the corresponding compounds. The 3,3',5,5'-tetrachloro-2-iodo-4,4'-bipyridine showed significant antiproliferation activity against the A375 cell line, and lower toxicity on BJ fibroblasts. Through in silico studies, the stereoelectronic features of possible sites determining the bioactivity were explored. These results pave the way for the utilization of iodinated 4,4'-bipyridines as templates to design new promising HaB-enabled inhibitors of MM cell proliferation.

Thymoquinone oxime synthesis and its effects on melanoma cells: cytotoxic, genotoxic, and apoptotic evaluation

Strong evidence supports the anticancer properties of natural plant product isolates. The cytotoxic, genotoxic, and apoptotic properties of an oxime derivative of thymoquinone (TQ) in melanoma cancer cells were investigated. The structure of TQ-Oxime was elucidated through nuclear magnetic resonance, and its effect on B16F10 and L929 cell lines was assessed using a luminometric adenosine triphosphate assay. Intracellular reactive oxygen species (iROS) were quantified via fluorometry, mitochondrial membrane potential (MMP) was assessed using flow cytometry, glutathione (GSH) levels were measured using a luminometric GSH/oxidized glutathione assay, DNA damage via comet assay, and apoptosis was detected using acridine orange/ethidium bromide staining. Concentrations (0.5-20 μM) of TQ-Oxime significantly increased cytotoxicity, DNA damage, apoptosis, and iROS, in a concentration-dependent manner compared (p < 0.001). In addition, MMP and GSH levels decreased significantly with increasing concentrations compared with the control (p < 0.001). Overall, these findings contribute to our understanding of the therapeutic potential of TQ and its derivatives in cancer treatment.

Bioactive Bismuth Compounds: Is Their Toxicity a Barrier to Therapeutic Use?

Bismuth compounds are considered relatively non-toxic, with their low solubility in aqueous solutions (e.g., biological fluids) being the major contributing factor to this property. Bismuth derivatives are widely used for the treatment of peptic ulcers, functional dyspepsia, and chronic gastritis. Moreover, the properties of bismuth compounds have also been extensively explored in two main fields of action: antimicrobial and anticancer. Despite the clinical interest of bismuth-based drugs, several side effects have also been reported. In fact, excessive acute ingestion of bismuth, or abuse for an extended period of time, can lead to toxicity. However, evidence has demonstrated that the discontinuation of these compounds usually reverses their toxic effects. Notwithstanding, the continuously growing use of bismuth products suggests that it is indeed part of our environment and our daily lives, which urges a more in-depth review and investigation into its possible undesired activities. Therefore, this review aims to update the pharmaco-toxicological properties of bismuth compounds. A special focus will be given to in vitro, in vivo, and clinical studies exploring their toxicity.

Bambu and its applications in the discovery of active molecules against melanoma

PURPOSE OR OBJECTIVE

Melanoma is one of the most dangerous forms of skin cancer and the discovery of novel drugs is an ongoing effort. Quantitative Structure Activity Relationship (QSAR) is a computational method that allows the estimation of the properties of a molecule, including its biological activity. QSAR models have been widely employed in the search for potential drug candidates, but also for agrochemicals and other molecules with applications in different branches of the industry. Here we present Bambu, a simple command line tool to generate QSAR models from high-throughput screening bioassays datasets.

METHODS

The tool was developed using the Python programming language and relies mainly on RDKit for molecule data manipulation, FLAML for automated machine learning and the PubChem REST API for data retrieval. As a proof-of-concept we have employed the tool to generate QSAR models for melanoma cell growth inhibition based on HTS data and used them to screen libraries of FDA-approved drugs and natural compounds. Additionally, Bambu was compared to QSAR-Co, another automated tool for QSAR model generation.

RESULTS

based on the developed tool we were able to produce QSAR models and identify a wide variety of molecules with potential melanoma cell growth inhibitors, many of which with anti-tumoral activity already described. The QSAR models are available through the URL http://caramel.ufpel.edu.br, and all data and code used to generate its models are available at Zenodo (https://doi.org/10.5281/zenodo.7495214). Bambu source code is available at GitHub (https://github.com/omixlab/bambu-v2). In the benchmark, Bambu was able to produce models with higher accuracy, recall, F1 and ROC AUC when compared to QSAR-Co for the selected datasets.

CONCLUSIONS

Bambu is an free and open source tool which facilitates the creation of QSAR models and can be futurely applied in a wide variety of drug discovery projects.

Prosopis juliflora (Sw.) DC phytochemicals induce apoptosis and inhibit cell proliferation signaling pathways, EMT, migration, invasion, angiogenesis and stem cell markers in melanoma cell lines

ETHNOPHARMACOLOGICAL RELEVANCE

Prosopis juliflora (Sw.), DC is a xerophytic plant species that extensively grow in Asia, Africa, Australia, and Brazil. From ancient time P. juliflora is being utilized in various folk remedies for example in wound healing, fever, inflammation, measles, excrescences, diarrhea and dysentery. Traditionally, gum, paste, and smoke obtained from the leaves and pods are applied for anticancer, antidiabetic, anti-inflammatory, and antimicrobial purposes.

AIM OF THE STUDY

Our previous studies have demonstrated the promising potential of Prosopis Juliflora leaves methanol extract (PJLME) against breast cancer, and suggested its possible integration as a complementary medicine for the effective management of breast cancer. However, evidence against how PJLME mechanistically target the cancer proliferative pathways and other targets is poorly understood. The basic aim of the present study was to understand the anti-melanoma potential of PJLME against B16f10 cells with possible mechanisms of action.

MATERIALS AND METHODS

MTT assay was used to determine cell viability. Wound and transwell migration assay was performed to check migration potential of cells after PJLME treatment, while clonogenic assay was carried out to understand its colony inhibition actvity. Flow cytometry was used to perform annexin V/PI assay (apoptosis assay), ROS assay, cell cycle analysis. In-vitro angiogenesis assay was performed to check formation of capillary like vascular structure after PJLME treatment. Apoptotic genes, signaling pathways markers, EMT markers and stem cell markers were determined by western blotting. In-vivo BALB/C mice xenograft model study was performed to check the effect of PJLME on in-vivo melanoma tumor growth.

RESULTS

The experimental outcome of the present study has clearly demonstrated the inhibition of growth, migration, invasion, colony formation and apoptosis inducing potential of PJLME against mouse melanoma cancer cells. Treatment of B16F10 melanoma cells with PJLME resulted in arrest of cell cycle at G0/G1 phase. Annexin V-FITC/PI assay confirmed the apoptosis inducing potential of PJLME in B16F10 and A375 melanoma cells. Furthermore, Western blot experiments confirmed that the treatment of PJLME downregulates the expression of anti-apoptotic gene like Bcl2 and increase the expression profile of pro-apoptotic genes like Bax, Bad, and Bak in B16F10 melanoma cells. HUVEC (Human umbilical vein endothelial cells) tube formation assay clearly demonstrated the anti-angiogenic potential of PJLME. The study also revealed that PJLME has potential to inhibit the Akt and Erk signaling pathways which are participating in cancer cell proliferation, migration, invasion etc. The outcome of qRT-PCR and immunoblotting analysis clearly unveiled that PJLME treatment leads to downregulation of epithelial-mesenchymal transition (EMT) as well as stem cell markers. Finally, the in-vivo animal xenograft model study also revealed the anti-melanoma potential of PJLME by significantly inhibiting the B16F10 melanoma tumor growth in BALB/c mice model. The LC-ESI-MS/MS analysis of PJLME showed the presence of variety of bioactive molecules associated with anticancer effects.

CONCLUSION

The outcome of the present investigation clearly demonstrated the anti-melanoma potential of PJLME against B16f10 melanoma cells. PJLME can be explored as an adjuvant or complementary therapy against melanoma cancer, however further studies are required to understand the clinical efficacy of PJLME. Nevertheless, it can be further explored as a promising resource for identification of novel anticancer candidate drug.

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.

Phytochemical Analysis, In Vitro Biological Activities, and Computer-Aided Analysis of Potentilla nepalensis Hook Compounds as Potential Melanoma Inhibitors Based on Molecular Docking, MD Simulations, and ADMET

Potentilla nepalensis Hook is a perennial Himalayan medicinal herb of the Rosaceae family. The present study aimed to evaluate biological activities such as the antioxidant, antibacterial, and anticancer activities of roots and shoots of P. nepalensis and its synergistic antibacterial activity with antibacterial drugs. Folin-Ciocalteau and aluminium chloride methods were used for the calculation of total phenolic (TPC) and flavonoid content (TFC). A DPPH radical scavenging assay and broth dilution method were used for the determination of the antioxidant and antibacterial activity of the root and shoot extracts of P. nepalensis. Cytotoxic activity was determined using a colorimetric MTT assay. Further, phytochemical characterization of the root and shoot extracts was performed using the Gas chromatography-mass spectrophotometry (GC-MS) method. The TPC and TFC were found to be higher in the methanolic root extract of P. nepalensis. The methanolic shoot extract of P. nepalensis showed good antioxidant activity, while then-hexane root extract of P. nepalensis showed strong cytotoxic activity against tested SK-MEL-28 cells. Subsequently, in silico molecular docking studies of the identified bioactive compounds predicted potential anticancer properties. This study can lead to the production of new herbal medicines for various diseases employing P. nepalensis, leading to the creation of new medications.

A step forward on the in vitro and in vivo assessment of a novel nanomedicine against melanoma

Melanoma is the most aggressive form of skin cancer, with increasing incidence and mortality rates. To overcome current treatment limitations, a hybrid molecule (HM) combining a triazene and a ʟ-tyrosine analogue, was recently synthesized, incorporated in long blood circulating liposomes (LIP HM) and validated in an immunocompetent melanoma model. The present work constitutes a step forward in the therapeutic assessment of HM formulations. Here, human melanoma cells, A375 and MNT-1, were used and dacarbazine (DTIC), a triazene drug clinically available as first-line treatment for melanoma, constituted the positive control. In cell cycle analysis, A375 cells, after 24-h incubation with HM (60 μM) and DTIC (70 μM), resulted in a 1.2 fold increase (related to control) in the percentage of cells in G0/G1 phase. The therapeutic activity was evaluated in a human murine melanoma model (subcutaneously injected with A375 cells) to most closely resemble the human pathology. Animals treated with LIP HM exhibited the highest antimelanoma effect resulting in a 6-, 5- and 4-fold reduction on tumor volume compared to negative control, Free HM and DTIC groups, respectively. No toxic side effects were detected. Overall, these results constitute another step forward in the validation of the antimelanoma activity of LIP HM, using a murine model that more accurately simulates the pathology that occurs in human patients.

Immunogenic cell death in cancer: concept and therapeutic implications

Mammalian cells responding to specific perturbations of homeostasis can undergo a regulated variant of cell death that elicits adaptive immune responses. As immunogenic cell death (ICD) can only occur in a precise cellular and organismal context, it should be conceptually differentiated from instances of immunostimulation or inflammatory responses that do not mechanistically depend on cellular demise. Here, we critically discuss key conceptual and mechanistic aspects of ICD and its implications for cancer (immuno)therapy.

Dabrafenib-Trametinib and Radiotherapy for Oligoprogressive BRAF Mutant Advanced Melanoma

The clinical management of metastatic melanoma has been changed by BRAF (BRAFi) and MEK inhibitors (MEKi), which represent a standard treatment for BRAF-mutant melanoma. In oligoprogressive melanoma patients with BRAF mutations, target therapy can be combined with loco-regional radiotherapy (RT). However, the association of BRAF/MEK inhibitors and RT needs to be carefully monitored for potential increased toxicity. Despite the availability of some reports regarding the tolerability of RT + target therapy, data on simultaneous RT and BRAFi/MEKi are limited and mostly focused on the BRAFi vemurafenib. Here, we report a series of metastatic melanoma patients who received fractioned RT regimens for oligoprogressive disease in combination with the BRAFi dabrafenib and the MEKi trametinib, which have continued beyond progression. None of the cases developed relevant adverse events while receiving RT or interrupted dabrafenib and trametinib administration. These cases suggest that a long period of dabrafenib/trametinib interruption during radiotherapy for oligoprogressive disease can be avoided. Prospective trials are warranted to assess the efficacy and safety of the contemporary administration of BRAF/MEK inhibitors and radiotherapy for oligoprogressive disease.

Role of the tumor microenvironment in malignant melanoma organoids during the development and metastasis of tumors

Malignant melanoma (MM) is the most metastatic and aggressive form of skin cancer, and carries a high risk of death. Immune-checkpoint inhibitor therapy and molecular-targeted therapy can prolong the survival of patients with advanced MM significantly. However, the low response rate and inevitable drug resistance prevent further improvements in efficacy, which is closely related to the tumor microenvironment (TME). The TME refers to the tumor stroma, including fibroblasts, keratinocytes, immune cells, soluble molecules, and extracellular matrix (ECM). The dynamic interaction between the TME and tumor cells is very important for the growth, local invasion, and metastatic spread of tumor cells. A patient-derived organoid (PDO) model involves isolation of tumor tissue from patients with MM and culturing it in vitro in a three-dimensional pattern. Compared with traditional cultivation methods, the PDO model preserves the heterogeneity of the tissue structure of MM and demonstrates the interaction between MM cells and the TME. It can reproduce the characteristics of proliferation, migration, and invasion of MM cells, and better simulate the structural function of MM in vivo. This review explores the role of each TME component in development of the PDO model. This review will provide a reference for research on the drug screening and targeted treatment using PDOs, particularly for the immunotherapy of MM.

Melanoma Management: From Epidemiology to Treatment and Latest Advances

Simple Summary

Melanoma is a major public health issue that claims the lives of thousands of people every year. Furthermore, the outlook for the coming years is not encouraging with increasing morbidity and mortality trends. This review aims to offer an updated overview of various aspects related to cutaneous melanoma, from epidemiology, etiology, clinical presentation, prevention, diagnosis and staging. Moreover, conventional treatments currently available as well as the latest advances in clinical trials regarding new drugs and/or combinations, including nanotechnology-based strategies are also reviewed.

Abstract

Melanoma is the deadliest skin cancer, whose morbidity and mortality indicators show an increasing trend worldwide. In addition to its great heterogeneity, melanoma has a high metastatic potential, resulting in very limited response to therapies currently available, which were restricted to surgery, radiotherapy and chemotherapy for many years. Advances in knowledge about the pathophysiological mechanisms of the disease have allowed the development of new therapeutic classes, such as immune checkpoint and small molecule kinase inhibitors. However, despite the incontestable progress in the quality of life and survival rates of the patients, effectiveness is still far from desired. Some adverse side effects and resistance mechanisms are the main barriers. Thus, the search for better options has resulted in many clinical trials that are now investigating new drugs and/or combinations. The low water solubility of drugs, low stability and rapid metabolism limit the clinical potential and therapeutic use of some compounds. Thus, the research of nanotechnology-based strategies is being explored as the basis for the broad application of different types of nanosystems in the treatment of melanoma. Future development focus on challenges understanding the mechanisms that make these nanosystems more effective.

Deep learning and machine intelligence: New computational modeling techniques for discovery of the combination rules and pharmacodynamic characteristics of Traditional Chinese Medicine

It has been increasingly accepted that Multi-Ingredient-Based interventions provide advantages over single-target therapy for complex diseases. With the growing development of Traditional Chinese Medicine (TCM) and continually being refined of a holistic view, "multi-target" and "multi-pathway" integration characteristics of which are being accepted. However, its effector substances, efficacy targets, especially the combination rules and mechanisms remain unclear, and more powerful strategies to interpret the synergy are urgently needed. Artificial intelligence (AI) and computer vision lead to a rapidly expanding in many fields, including diagnosis and treatment of TCM. AI technology significantly improves the reliability and accuracy of diagnostics, target screening, and new drug research. While all AI techniques are capable of matching models to biological big data, the specific methods are complex and varied. Retrieves literature by the keywords such as "artificial intelligence", "machine learning", "deep learning", "traditional Chinese medicine" and "Chinese medicine". Search the application of computer algorithms of TCM between 2000 and 2021 in PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), Elsevier and Springer. This review concentrates on the application of computational in herb quality evaluation, drug target discovery, optimized compatibility and medical diagnoses of TCM. We describe the characteristics of biological data for which different AI techniques are applicable, and discuss some of the best data mining methods and the problems faced by deep learning and machine learning methods applied to Chinese medicine.

How to Treat Melanoma? The Current Status of Innovative Nanotechnological Strategies and the Role of Minimally Invasive Approaches like PTT and PDT

Melanoma is the most aggressive type of skin cancer, the incidence and mortality of which are increasing worldwide. Its extensive degree of heterogeneity has limited its response to existing therapies. For many years the therapeutic strategies were limited to surgery, radiotherapy, and chemotherapy. Fortunately, advances in knowledge have allowed the development of new therapeutic strategies. Despite the undoubted progress, alternative therapies are still under research. In this context, nanotechnology is also positioned as a strong and promising tool to develop nanosystems that act as drug carriers and/or light absorbents to potentially improve photothermal and photodynamic therapies outcomes. This review describes the latest advances in nanotechnology field in the treatment of melanoma from 2011 to 2022. The challenges in the translation of nanotechnology-based therapies to clinical applications are also discussed. To sum up, great progress has been made in the field of nanotechnology-based therapies, and our understanding in this field has greatly improved. Although few therapies based on nanoparticulate systems have advanced to clinical trials, it is expected that a large number will come into clinical use in the near future. With its high sensitivity, specificity, and multiplexed measurement capacity, it provides great opportunities to improve melanoma treatment, which will ultimately lead to enhanced patient survival rates.

A novel inflammatory response-related signature predicts the prognosis of cutaneous melanoma and the effect of antitumor drugs

Cutaneous melanoma (CM) is a skin cancer that is highly metastatic and aggressive, with a dismal prognosis. This is the first study to use inflammatory response-related genes to build a model and evaluate their predictive significance in CM. This study used public databases to download CM patients' mRNA expression profiles and clinical data to create multigene prognostic markers in the UCSC cohort. We compared overall survival (OS) between high- and low-risk groups using the Kaplan-Meier curve and determined independent predictors using Cox analysis. We also used enrichment analysis to assess immune cell infiltration fraction and immune pathway-related activity using KEGG enrichment analysis. Furthermore, we detected prognostic genes' mRNA and protein expression in CM and normal skin tissues using qRT-PCR and immunohistochemistry. Finally, we developed a 5-gene predictive model that showed that patients in the high-risk group had a considerably shorter OS than those in the low-risk group. The analysis of the receiver operating characteristic (ROC) curve proved the model's predictive ability. We also conducted a drug sensitivity analysis and discovered that the expression levels of prognostic genes were substantially linked with cancer cell sensitivity to antitumor medicines. The findings show that the model we developed, which consists of five inflammatory response-related genes, can be used to forecast the prognosis and immunological state of CM, giving personalized and precision medicine a new goal and direction.

Construction of immunotherapy-related prognostic gene signature and small molecule drug prediction for cutaneous melanoma

Background

Cutaneous melanoma (CM), a kind of skin cancer with a high rate of advanced mortality, exhibits a wide variety of driver and transmitter gene alterations in the immunological tumor microenvironment (TME) associated with tumor cell survival and proliferation.

Methods

We analyzed the immunological infiltration of TME cells in normal and malignant tissues using 469 CM and 556 normal skin samples. We used a single sample gene set enrichment assay (ssGSEA) to quantify the relative abundance of 28 cells, then used the LASSO COX regression model to develop a riskScore prognostic model, followed by a small molecule drug screening and molecular docking validation, which was then validated using qRT-PCR and IHC.

Results

We developed a prognosis model around seven essential protective genes for the first time, dramatically elevated in tumor tissues, as did immune cell infiltration. Multivariate Cox regression results indicated that riskScore is an independent and robust prognostic indicator, and its predictive value in immunotherapy was verified. Additionally, we identified Gabapentin as a possible small molecule therapeutic for CM.

Conclusions

A riskScore model was developed in this work to analyze patient prognosis, TME cell infiltration features, and treatment responsiveness. The development of this model not only aids in predicting patient response to immunotherapy but also has significant implications for the development of novel immunotherapeutic agents and the promotion of tailored treatment regimens.

The Multi-Omics Landscape and Clinical Relevance of the Immunological Signature of Phagocytosis Regulators: Implications for Risk Classification and Frontline Therapies in Skin Cutaneous Melanoma

Simple Summary

In this study, we focused on exploring phagocytosis regulators’ expression and mutational characteristics in skin cutaneous melanoma samples and delineating two molecular subtypes based on expression characteristics. We determined the relationship between phagocytosis regulators and survival by survival analysis of molecular subtypes. We then constructed a survival model (PRRS) to further quantify the criteria. Moreover, we combined pathway analysis, immune infiltration analysis, and mutation analysis to deeply explore the effects of phagocytosis regulators on skin cutaneous melanoma samples.

Abstract

Tumor-associated macrophages (TAMs) have gained considerable attention as therapeutic targets. Monoclonal antibody treatments directed against tumor antigens contribute significantly to cancer cell clearance by activating macrophages to phagocytose tumor cells. Due to its complicated genetic and molecular pathways, skin cutaneous melanoma (SKCM) has not yet attained the expected clinical efficacy and prognosis when compared to other skin cancers. Therefore, we chose TAMs as an entrance point. This study aimed to thoroughly assess the dysregulation and regulatory role of phagocytosis regulators in SKCM, as well as to understand their regulatory patterns in SKCM. This study subtyped prognosis-related phagocytosis regulators to investigate prognostic differences between subtypes. Then, we screened prognostic factors and constructed phagocytosis-related scoring models for survival prediction using differentially expressed genes (DEGs) between subtypes. Additionally, we investigated alternative treatment options using chemotherapeutic drug response data and clinical cohort treatment data. We first characterized and generalized phagocytosis regulators in SKCM and extensively examined the tumor immune cell infiltration. We created two phagocytosis regulator-related system (PRRS) phenotypes and derived PRRS scores using a principal component analysis (PCA) technique. We discovered that subtypes with low PRRS scores had a poor prognosis and decreased immune checkpoint-associated gene expression levels. We observed significant therapeutic and clinical improvements in patients with higher PRRS scores. Our findings imply that the PRRS scoring system can be employed as an independent and robust prognostic biomarker, serving as a critical reference point for developing novel immunotherapeutic methods.

Nobiletin Induces Ferroptosis in Human Skin Melanoma Cells Through the GSK3β-Mediated Keap1/Nrf2/HO-1 Signalling Pathway

Melanoma is an aggressive malignant skin tumour with an increasing global incidence. However, current treatments have limitations owing to the acquired tumour drug resistance. Ferroptosis is a recently discovered form of programmed cell death characterised by iron accumulation and lipid peroxidation and plays a critical role in tumour growth inhibition. Recently, ferroptosis inducers have been regarded as a promising therapeutic strategy to overcome apoptosis resistance in tumour cells. In this study, we reported that nobiletin, a natural product isolated from citrus peel, and exhibited antitumour activity by inducing ferroptosis in melanoma cells. Subsequently, we further explored the potential mechanism of nobiletin-induced ferroptosis, and found that the expression level of glycogen synthase kinase 3β (GSK3β) in the skin tissue of patients with melanoma was significantly reduced compared to that in the skin of normal tissue. Additionally, nobiletin increased GSK3β expression in melanoma cells. Moreover, the level of Kelch-like Ech-associated protein-1 (Keap1) was increased, while the level of nuclear factor erythroid 2-related factor 2 (Nrf2), and haem oxygenase-1 (HO-1) was decreased in nobiletin-treated melanoma cells, suggesting that the antioxidant defence system was downregulated. Furthermore, knockdown of GSK3β significantly reduced nobiletin-induced ferroptosis and upregulated the Keap1/Nrf2/HO-1 signalling pathway, while the opposite was observed in cells overexpressing GSK3β. In addition, molecular docking assay results indicated that nobiletin showed strong binding affinities for GSK3β, Keap1, Nrf2, and HO-1. Taken together, our results demonstrated that nobiletin could induce ferroptosis by regulating the GSK3β-mediated Keap1/Nrf2/HO-1 signalling pathway in human melanoma cells. Hence, nobiletin stands as a promising drug candidate for melanoma treatment with development prospects.

Feasibility of Concentric Electrodes in Contact Irreversible Electroporation for Superficial Lesion Treatment

<i>Objective:</i> Contact irreversible electroporation (IRE) is a method for ablating cells by applying electric pulses via surface electrodes in contact with a target tissue. To facilitate the application of the contact IRE to superficial lesion treatment, this study further extended the ablation depth, which had been limited to a 400-m depth in our previous study, by using concentric electrodes. <i>Methods:</i> A prototype device of concentric electrodes was manufactured using a Teflon-coated copper wire inserted in a copper tube. The ablation area was experimentally determined using a tissue phantom comprising 3D cultured fibroblasts and compared with the electric field distribution obtained using numerical analyses. </i>Results:</i> Experiments showed that cells 540 m from the surface of the tissue phantom were necrotized by the application of 150 pulses at 100 V. The outline of the ablation area agreed well with the contour line of 0.4 kV/cm acquired by the analyses. The ablation depth predicted for the concentric electrode using this critical electric field was 1.4 times deeper than that for the parallel electrode. For the actual application of treatment, a multiple-electrode device that bundles several pairs of concentric electrodes was developed, and confirmed that to be effective for treating wide areas with a single treatment. <i>Conclusion:</i> The electric field estimated by the analyses with the experimentally determined threshold confirmed that concentric electrodes could attain a deeper ablation than parallel electrodes. <i>Significance:</i> Using the concentric electrodes, we were able to localize ablation to specific target cells with much less damage to neighboring cells.

Nanoparticles in Clinical Translation for Cancer Therapy

The advent of cancer therapeutics brought a paradigm shift from conventional therapy to precision medicine. The new therapeutic modalities accomplished through the properties of nanomaterials have extended their scope in cancer therapy beyond conventional drug delivery. Nanoparticles can be channeled in cancer therapy to encapsulate active pharmaceutical ingredients and deliver them to the tumor site in a more efficient manner. This review enumerates various types of nanoparticles that have entered clinical trials for cancer treatment. The obstacles in the journey of nanodrug from clinic to market are reviewed. Furthermore, the latest developments in using nanoparticles in cancer therapy are also highlighted.

Combination of phototherapy with immune checkpoint blockade: Theory and practice in cancer

Immune checkpoint blockade (ICB) therapy has evolved as a revolutionized therapeutic modality to eradicate tumor cells by releasing the brake of the antitumor immune response. However, only a subset of patients could benefit from ICB treatment currently. Phototherapy usually includes photothermal therapy (PTT) and photodynamic therapy (PDT). PTT exerts a local therapeutic effect by using photothermal agents to generate heat upon laser irradiation. PDT utilizes irradiated photosensitizers with a laser to produce reactive oxygen species to kill the target cells. Both PTT and PDT can induce immunogenic cell death in tumors to activate antigen-presenting cells and promote T cell infiltration. Therefore, combining ICB treatment with PTT/PDT can enhance the antitumor immune response and prevent tumor metastases and recurrence. In this review, we summarized the mechanism of phototherapy in cancer immunotherapy and discussed the recent advances in the development of phototherapy combined with ICB therapy to treat malignant tumors. Moreover, we also outlined the significant progress of phototherapy combined with targeted therapy or chemotherapy to improve ICB in preclinical and clinical studies. Finally, we analyzed the current challenges of this novel combination treatment regimen. We believe that the next-generation technology breakthrough in cancer treatment may come from this combinational win-win strategy of photoimmunotherapy.