The leaf extract of Mallotus japonicus and its major active constituent, rutin,suppressed on melanin production in murine B16F1 melanoma

Objective: To find anti-melanogenesis materials used in whitening cosmetics.Methods: The ethanolic leaf extract of Mallotus japonicus(M. japonicus) having an anti-melanogenesis activity was separated by a sephadex LH-20 chromatography. Each fraction was measured for its tyrosinase inhibitory activity together with its polyphenol content using the Folin–Ciocalteu method. The anti-melanogenesis activity of the active fractions was determined by the melanin content in the murine B16F1 melanoma. The active fractions were put together due to similar constituents, and then separated by high performance liquid chromatography using a C-18 ODS column. The major antimelanogenesis compound was identified using1 H and13C-NMR and liquid chromatography-mass spectrometry.Results: The ethanolic leaf extract of M. japonicus showed an anti-tyrosinase activity with a high polyphenol content, resulting in suppression of melanin production in the B16F1 melanoma. The extract was separated and the active compound was identical as rutin based on the1 H,13C-NMR and liquid chromatography-mass spectrometry analysis data. In addition, the rutin treatment with cells reduced the melanin content in a concentration dependent manner without any cell toxicity. The leaf extract of M. japonicus containing rutin would be useful in whitening cosmetics for protection from UV-light exposure to be limiting the accumulation of melanin in skin.Conclusions: The leaf extract of M. japonicus and/or rutin isolated from the extract as a key whitening agent would be useful as a whitening cosmetic material for protecting against disorder skin due to melanin accumulation.

Biomedical overview of melanin.1.Updating melanin biology and chemistry,physico-chemical properties,melanoma tumors,and photothermal therapy

Melanins(eumelanin,pheomelanin,and allomelanin)represent a very,if not themost,important group of biological pigments.Their biological roles are multiple,from photoprotection to antioxidant activity,heavy metal disposal or the myriad uses of color in organisms across all Phyla.In the first part of this review,eumelanin biology and some chemical aspects will be presented,as well as key physico-chemical features that make this biological pigment so interesting.The principal characteristics of the melanocyte,the melanin-synthesizing cell in mammals,will also be introduced.Transformed melanocytes are the cause of one of the most devastating known cancers:the malignant melanoma.Epidemiology and molecular signaling aspects will be presented next,as well as the principal advances in promising oncotherapies designed and applied for the treatment of melanoma.In particular,on account of the photo-physical properties of melanin,special details will be provided regarding the use of photothermal therapy for melanoma treatment.

In vitro polymerization of the dopamine-borate melanin precursor:A proof-of-concept regarding^(10)boron neutron-capture therapy for melanoma

The^(10)boron neutron-capture therapy(BNCT)is an emerging antitumoral method that shows increasing biomedical interest.BNCT is based on the selective accumulation of the^(10)boron isotope within the tumor,which is then irradiated with low-energy thermal neutrons,generating nuclear fission that produces 7lithium,4helium,andγrays.Simple catechol-borate esters have been rather overlooked as precursors of melanin biosynthesis,and therefore,a proof-of-concept approach for using dopamine-borate(DABO)as a suitable boron-containing candidate for potential BNCT is presented here.DABO can spontaneously oxidize and autopolymerize in vitro,giving a soluble,eumelaninlike brown-black poly-DABO product.Melanotic melanoma cell cultures treated with 1 mM DABO for 24 and 48 h were viable and showed no signs of damage or cell death.The stability and possible trans-esterification of DABO is shortly discussed.Chemical calculations and quantitative structure-activity relationships(QSAR)analysis of DABO and the BNCT agent BPA indicated that they should be cell permeant and accumulate within lysosomes and melanosomes.Molecular modeling allows visualization of both the DABO precursor and the structure of a borate derivative of the proposed catechol-porphycene model for eumelanin,showing interesting features from molecular orbital calculations.The main difference between DABO and other agents,such as BPA,is that it is not a boronic acid nor a boron cluster.This simple catechol-borate ester(protected from oxidation and blackening)could be administrated to living cells and organisms,in which biosynthesis of boron-melanin in melanoma melanocytes can lead to improved BNCT.

Polydopamine Particles Effect on Melanoma Cells Proliferation and Melanin Secretion

Melanin is a biopolymer implicated in the protection of cellular membranes and DNA produced by melanocytes. This pigment has a dual role and should be considered as a photo-protector and as a photosensitizer due to its interaction with UV. The design of multifunctional and biologically responsive coatings is of major interest in modern biomaterials science. The aim of this study is not only to characterize the deposition of multilayered polyelectrolytes films made from polydopamine particles and polyamines like poly-(L-lysine hydrobromide) (PLL), but also to evaluate melanoma cells activity in terms of proliferation and their capacity to stimulate melanin secretion. One could expect that the presence of a melanin like material in the film may have a positive or a negative feedback on the melanin biosynthesis and consequently on melanoma development. Some comparisons are also done with pure polydopamine grains in suspension in the cell culture medium, to investigate if the immobilization of the polydopamine grains has an influence on their bioactivity.

Biomedical overview of melanin.2.Updating molecular modeling,synthesis mechanism,and supramolecular properties regarding melanoma therapy

Melanins represent one of the most ancient and important group of natural macromolecular pigments.They have multiple biological roles in almost all organisms across the Phyla,examples being photoprotection,anti-oxidative action,radical scavenger activity,and heavy metal removal.From the biomedical point of view,melanocytes are involved in the origin of melanoma tumors,and the main therapeutic advances for their treatment have been revised in Part 1 of this review.The chemical structure of eumelanin is a biological concern of great importance,and therefore,exploring theoretical molecular models and synthesis mechanisms will be here described,as well as molecular orbital features and supramolecular organization,which are responsible for the key properties that make these biological pigments so important,and so fascinating.Ultimately,this updated overview is devoted to describe present structural models and physico-chemical characteristics of eumelanin,in order to explain and utilize melanin properties on which new photothermal and ultrasonic protocols for melanoma treatment can be devised and applied.

Low-molecular-weight fucoidan inhibits the proliferation of melanoma via Bcl-2 phosphorylation and PTEN/AKT pathway

Fucoidan,a sulfate polysaccharide obtained from brown seaweed,has various bioactive properties,including anti-inflammatory,anti-cancer,anti-viral,anti-oxidant,anti-coagulant,anti-thrombotic,anti-angiogenic,and anti-Helicobacter pylori properties.However,the effects of low-molecular-weight fucoidan(LMW-F)on melanoma cell lines and three dimensional(3D)cell culture models are not well understood.This study aimed to investigate the effects of LMW-F on A375 human melanoma cells and cryopreserved biospecimens derived from patients with advanced melanoma.Ultrasonic wave was used to fragment fucoidan derived from Fucus vesiculosus into smaller LMW-F.MTT and live/dead assays showed that LMW-F inhibited cell proliferation in both A375 cells and patientderived melanoma explants in a 3D-printed collagen scaffold.The PTEN/AKT pathway was found to be involved in the anti-melanoma effects of fucoidan.Western blot analysis revealed that LMW-F reduced the phosphorylation of Bcl-2 at Thr 56,which was associated with the prevention of anti-apoptotic activity of cancer cells.Our findings suggested that LMW-F could enhance anti-melanoma chemotherapy and improve the outcomes of patients with melanoma resistance.

Biological characteristics and clinical management of uveal and conjunctival melanoma

Uveal and conjunctival melanomas are relatively rare tumors;nonetheless,they pose a significant risk of mortality for a large number of affected individuals.The pathogenesis of melanoma at different sites is very similar,however,the prognosis for patients with ocular melanoma remains unfavourable,primarily due to its distinctive genetic profile and tumor microenvironment.Regardless of considerable advances in understanding the genetic characteristics and biological behaviour,the treatment of uveal and conjunctival melanoma remains a formidable challenge.To enhance the prospect of success,collaborative efforts involving medical professionals and researchers in thefields of ocular biology and oncology are essential.Current data show a lack of well-designed randomized clinical trials and limited benefits in current forms of treatment for these tumors.Despite advancements in the development of effective melanoma therapeutic strategies,all current treatments for uveal melanoma(UM)and conjunctival melanoma(CoM)remain unsatisfactory,resulting in a poor long-term prognosis.Ongoing trials offer hope for positive outcomes in advanced and metastatic tumors.A more comprehensive understanding of the genetic and molecular abnormalities involved in the development and progression of ocular melanomas opens the way for the development of personalized therapy,with various potential therapeutic targets currently under consideration.Increased comprehension of the molecular pathogenesis of UM and CoM and their specificities may aid in the development of new and more effective systemic therapeutic agents,with the hope of improving the prognosis for patients with metastatic disease.

C19MC miRNA-520G induces SP100 antiviral gene transcription and inhibits melanin production in skin cutaneous melanoma

SP100 is an antiviral protein that restricts the productive stage of human papillomavirus(HPV)and multiple other viruses,and viruses in turn block sUMO-1-mediated stabilization of SP100 and promotes its degradation(Table S1).Interferon(IFN)signaling could still produce more SP100 through transcription to counteract viruses.1 Viruses also disable the transcriptional up-regulation of SP100 to achieve persistent infection in hosts.

Formation of Natural Melanin/TiO_(2) Nanostructure Hybrids with Enhanced Optical,Thermal and Magnetic Properties as a Soft Material

The natural Melanin/TiO_(2) was synthesized by the use of ultrasonication under UV radiation.The influence of natural melanin on the structural,optical and thermal properties of TiO_(2) nanoparticles was investigated by using Fourier transform infrared spectroscopy,thermogravimetric analysis and UV-Vis spectroscopy.It was observed that incorporating natural melanin on TiO_(2) nanoparticles(TiO_(2)-Mel)occurred at 2.01 eV with a low value of Urbach energy around 100 meV indicating improvement in the crystalline structure.Magnetic measurement at room temperature showed diamagnetic behavior.Furthermore,thermal results showed that TiO_(2)-Mel is stable even at temperatures up to 400℃.According to the results obtained by the thermal stability of melanin with titanium dioxide,it can be a good candidate in many applications such as solar cells and optoelectronics.

CRABP2 regulates infiltration of cancer-associated fibroblasts and immune response in melanoma

Finding biomarkers for immunotherapy is an urgent issue in cancer treatment.Cellular retinoic acid-binding protein 2(CRABP2)is a controversial factor in the occurrence and development of human tumors.However,there is limited research on the relationship between CRABP2 and immunotherapy response.This study found that negative correlations of CRABP2 and immune checkpoint markers(PD-1,PD-L1,and CTLA-4)were observed in breast invasive carcinoma(BRCA),skin cutaneous melanoma(SKCM),stomach adenocarcinoma(STAD)and testicular germ cell tumors(TGCT).In particular,in SKCM patients who were treated with PD-1 inhibitors,high levels of CRABP2 predicted poor prognosis.Additionally,CRABP2 expression was elevated in cancer-associated fibroblasts(CAFs)at the single-cell level.The expression of CRABP2 was positively correlated with markers of CAFs,such as MFAP5,PDPN,ITGA11,PDGFRα/βand THY1 in SKCM.To validate the tumor-promoting effect of CRABP2 in vivo,SKCM xenograft mice models with CRABP2 overexpression have been constructed.These models showed an increase in tumor weight and volume.Enrichment analysis indicated that CRABP2 may be involved in immunerelated pathways of SKCM,such as extracellular matrix(ECM)receptor interaction and epithelial-mesenchymal transition(EMT).The study suggests that CRABP2 may regulate immunotherapy in SKCM patients by influencing infiltration of CAFs.In conclusion,this study provides new insights into the role of CRABP2 in immunotherapy response.The findings suggest that CRABP2 may be a promising biomarker for PD-1 inhibitors in SKCM patients.Further research is needed to confirm these findings and to explore the clinical implications of CRABP2 in immunotherapy.

Intracranial hypertension as the primary symptom of malignant melanoma:A case report

BACKGROUND The etiological diagnosis of intracranial hypertension is quite complicated but important in clinical practice.Some common causes are craniocerebral injury,intracranial space-occupying lesion,subarachnoid hemorrhage,and hydrocephalus.When a patient presents with intracranial hypertension,the common causes are to be considered first so that other causes would be dismissed.With the morbidity lower than 9%,neuromelanin is very rare.Common symp-toms include nerve damage symptoms,epilepsy,psychiatric symptoms,and cognitive disorders.CASE SUMMARY We present a patient with melanoma which manifested with isolated intracranial hypertension without any other neurological signs.A 22-year-old male had repeated nausea and vomiting for 2 mo with Babinski sign(+)on both sides,nuchal rigidity,and subarachnoid hemorrhage.He had been diagnosed with melanoma and was given surgery and whole-brain radiation.Ultimately,the patient died 2 mo later.CONCLUSION Malignant melanoma should be taken into consideration in the differential diagnosis of intracranial hypertension.

Primary thoracolumbar intraspinal malignant melanoma:A case report

BACKGROUND Primary intraspinal malignant melanoma is a very rare tumor that most often occurs in the cervical,thoracic,or thoracolumbar segment.CASE SUMMARY A rare case of primary thoracolumbar malignant melanoma is described.A 45-year-old female patient complained of low back pain with numbness and fatigue in both lower limbs.MR revealed an intradural space-occupying lesion at the thoracic 12 to lumbar 1 level.The tumor was partially excised,and a malignant melanoma was confirmed by histopathology.CONCLUSION Primary intraspinal malignant melanoma has rarely been reported,and surgical resection and related characteristics and diagnoses have been discussed.

Endoscopic ultrasound features of rectal melanoma:A case report and review of literature

BACKGROUND Rectal mucosal melanoma is a rare and highly aggressive disease.Common symptoms include anal pain,an anal mass,or bleeding.As such,the disease is usually detected on rectal examination of patients with other suspected anorectal diseases.However,due to its rarity and nonspecific symptoms,melanoma of the rectal mucosa is easily misdiagnosed.CASE SUMMARY This report describes the case of a 58-year-old female patient who presented with a history of blood in her stool for the prior one or two months,without any identifiable cause.During colonoscopy,a bulge of approximately 2.2 cm×2.0 cm was identified.Subsequently,the patient underwent endoscopic ultrasound(EUS)to characterize the depth of invasion of the lesions.EUS suggested a hypoechoic mucosal mass with involvement of the submucosal layer and heterogeneity of the internal echoes.Following surgical intervention,the excised tissue samples were examined and confirmed to be rectal malignant melanoma.The patient recovered well with no evidence of recurrence during follow-up.CONCLUSION This case shows that colonoscopy with EUS and pathological examination can accurately diagnose rare cases of rectal mucosal melanoma.

Absent in melanoma 2 attenuates proliferation and migration and promotes apoptosis of human colorectal cancer cells by activating P38MAPK signaling pathway

Colorectal cancer(CRC)stands among the top prevalent cancers worldwide and holds a prominent position as a major contributor to cancer-related mortality globally.Absent in melanoma 2(AIM2),a constituent of the interferoninducible hematopoietic interferon-inducible nuclear antigens with 200 amino acid repeats protein family,contributes to both cancer progression and inflammasome activation.Despite this understanding,the precise biological functions and molecular mechanisms governed by AIM2 in CRC remain elusive.Consequently,this study endeavors to assess AIM2’s expression levels,explore its potential antitumor effects,elucidate associated cancer-related processes,and decipher the underlying signaling pathways in CRC.Our findings showed a reduced AIM2 expression in most CRC cell lines.Elevation of AIM2 levels suppressed CRC cell proliferation and migration,altered cell cycle by inhibiting G1/S transition,and induced cell apoptosis.Further research uncovered the participation of P38 mitogen-activated protein kinase(P38MAPK)in AIM2-mediated modulation of CRC cell apoptosis and proliferation.Altogether,our achievements distinctly underscored AIM2’s antitumor role in CRC.AIM2 overexpression inhibited proliferation and migration and induced apoptosis of CRC cells via activating P38MAPK signaling pathway,indicating AIM2 as a prospective and novel therapeutic target for CRC.

Malignant melanoma:An important differential diagnosis for clear cell sarcoma of the gastrointestinal tract

A case report by Liu et al describes the characteristics of metastatic clear cell sarcoma(CCS)of the pancreas and provides valuable therapeutic insights for this rare malignancy.This case is interesting because of its rarity,suggesting that the pancreas may be a potential target organ for CCS,either primary or metastatic.At the same time,the authors also emphasize the importance of regular postoperative follow-up for timely detection of recurrent lesions,as CCS is characterized by a high degree of malignancy and a high rate of recurrent metastases.Considering that CCS of the gastrointestinal tract is easily confused with malignant melanoma(MM)of the gastrointestinal tract,here we compare the clinical features,histopathological and immunohistochemical characteristics,diagnosis,treatment,and prognosis of CCS and MM of the gastrointestinal tract,hoping to provide a reference for clinical work.

Circ_0053943 complexed with IGF2BP3 drives uveal melanoma progression via regulating N6-methyladenosine modification of Epidermal growth factor receptor

Numerous studies have characterized the critical role of circular RNAs(circRNAs)as regulatory factors in the progression of multiple cancers.However,the biological functions of circRNAs and their underlying molecular mechanisms in the progression of uveal melanoma(UM)remain enigmatic.In this study,we identified a novel circRNA,circ_0053943,through re-analysis of UM microarray data and quantitative RT-PCR.Circ_0053943 was found to be upregulated in UM and to promote the proliferation and metastatic ability of UM cells in both in vitro and in vivo settings.Mechanistically,circ_0053943 was observed to bind to the KH1 and KH2 domains of insulin-like growth factor 2 mRNA-binding protein 3(IGF2BP3),thereby enhancing the function of IGF2BP3 by stabilizing its target mRNA.RNA sequencing assays identified epidermal growth factor receptor(EGFR)as a target gene of circ_0053943 and IGF2BP3 at the transcriptional level.Rescue assays demonstrated that circ_0053943 exerts its biological function by stabilizing EGFR mRNA and regulating the downstream mitogen-activated protein kinase/extracellular signal-regulated kinase(MAPK/ERK)signaling pathway.Collectively,circ_0053943 may promote UM progression by stabilizing EGFR mRNA and activating the MAPK/ERK signaling pathway through the formation of a circ_0053943/IGF2BP3/EGFR RNA-protein ternary complex,thus providing a potential biomarker and therapeutic target for UM.

Uveal melanoma:Recent advances in immunotherapy

Uveal melanoma(UM)is the most common primary intraocular cancer in adults.The incidence in Europe and the United States is 6-7 per million population per year.Although most primary UMs can be successfully treated and locally controlled by irradiation therapy or local tumor resection,up to 50%of UM patients develop metastases that usually involve the liver and are fatal within 1 year.To date,chemotherapy and targeted treatments only obtain minimal responses in patients with metastatic UM,which is still characterized by poor prognosis.No standard therapeutic approaches for its prevention or treatment have been established.The application of immunotherapy agents,such as immune checkpoint inhibitors that are effective in cutaneous melanoma,has shown limited effects in the treatment of ocular disease.This is due to UM’s distinct genetics,natural history,and complex interaction with the immune system.Unlike cutaneous melanomas characterized mainly by BRAF or NRAS mutations,UMs are usually triggered by a mutation in GNAQ or GNA11.As a result,more effective immunotherapeutic approaches,such as cancer vaccines,adoptive cell transfer,and other new molecules are currently being studied.In this review,we examine novel immunotherapeutic strategies in clinical and preclinical studies and highlight the latest insight in immunotherapy and the development of tailored treatment of UM.

BET inhibitors potentiate melanoma ferroptosis and immunotherapy through AKR1C2 inhibition

Dear Editor,Ferroptosis,an iron-dependent form of cell death driven by overwhelming lipid peroxidation,represents a vulnerability in cancers,and therapeutic strategies to further potentiate ferroptosis hold great potential for melanoma treatment.

Amelanotic primary cervical malignant melanoma:A case report and review of literature

BACKGROUND Primary malignant melanoma of the cervix(PMMC)is an extremely rare disease that originates from primary cervical malignant melanoma and frequently re-presents a challenge in disease diagnosis due to unclarified clinical and histo-logical presentations,particularly those without melanin.CASE SUMMARY Here,we report a case of amelanotic PMMC,with a history of breast cancer and thyroid carcinoma.The patient was finally diagnosed by immunohistochemical staining and staged as IB2 based on the International Federation of Gynecology and Obstetrics with reference to National Comprehensive Cancer Network guide-lines and was treated with radical hysterectomy,bilateral salpingo-oophorectomy and pelvic lymphadenectomy.She then received combination therapy consisting of immunotherapy with tislelizumab and radiofrequency hyperthermia.She has remained free of disease for more than 1 year.CONCLUSION The differential diagnosis process reenforced the notion that immunohisto-chemical staining is the most reliable approach for amelanotic PMMC diagnosis.Due to the lack of established therapeutic guidelines,empirical information from limited available studies does not provide the rationale for treatment-decision making.By integrating'omics'technologies and patient-derived xenografts or mini-patient-derived xenograft models this will help to identify selective thera-peutic window(s)and screen the appropriate therapeutics for targeted therapies,immune checkpoint blockade or combination therapy strategies effectively and precisely that will ultimately improve patient survival.

Acalypha australis L.extract inhibits B16 melanoma cell metastasis through PI3K/AKT signaling pathway

Background:Melanoma is a deadly skin tumor resulting from the malignant transformation of melanocytes.It is highly malignant and invasive,with the highest mortality rate among skin cancers.Acalypha australis L.(AAL),a plant with dual medicinal and culinary purposes,is commonly regarded as an edible wild vegetable in southern China.Additionally,AAL has a long history of medicinal use in China,often employed for its hemostatic,anti-diarrheal,and anti-inflammatory properties.Modern pharmacology has demonstrated that AAL possesses functions such as weight loss,antimicrobial activity,antiviral effects,and treatment for ulcerative colitis.However,there is currently no research available regarding its effectiveness and mechanisms of action on melanoma.Methods:In this investigation,we used methyl thiazolyl tetrazolium assay to detect cell viability,transwell assay to detect cell migration and invasion ability,and Western blot assay to detect relevant signaling pathways.Results:The present study reveals that 2 mg/mL AAL effectively suppresses the metastasis of B16 cells,while simultaneously triggering the expression of key apoptosis-related proteins,including Bcl-2,Bax,and cleaved caspased 3.Subsequent investigations demonstrate that AAL exerts this inhibitory effect via the PI3K/AKT signal transduction pathway,as evidenced by the observed deficits in Ras,AKT,p-AKT,and PI3K expression levels.Conclusion:These findings indicated that AAL could be a valuable therapeutic option for reducing the metastatic potential of B16 melanoma cells.