Search Results (268)

Background: Actinic keratoses are common keratinocytic precursor lesions arising within chronically ultraviolet-damaged skin and are associated with an increased risk of progression to cutaneous squamous cell carcinoma. The concept of field cancerization has shifted therapeutic strategies from the treatment of isolated visible lesions toward broader field-directed approaches targeting both clinical and subclinical disease. Methods: This narrative review summarizes the rationale, mechanisms of action, efficacy profile, tolerability, and practical limitations of currently available field-directed therapies for actinic keratosis, including 5-fluorouracil, imiquimod, diclofenac, photodynamic therapy, and tirbanibulin. Based on their distinct biological targets, we propose a mechanism-based framework for sequential treatment strategies. Results: Available therapies act through partially non-overlapping mechanisms, including cytotoxic activity, immune activation, cyclooxygenase-2 inhibition, photodynamic oxidative damage, and tubulin/Src pathway inhibition. These complementary effects provide a biological rationale for sequential regimens aimed at addressing the heterogeneity of field cancerization. However, direct clinical evidence supporting specific treatment sequences remains limited, and proposed regimens should be interpreted as hypothesis-generating rather than as validated therapeutic protocols. Conclusions: Mechanism-based sequential field therapy may represent a rational strategy to optimize long-term control of actinic keratosis and field cancerization. Prospective comparative studies are needed to define optimal sequences, treatment intervals, patient selection criteria, and clinically meaningful endpoints, including sustained field clearance, recurrence reduction, tolerability, adherence, and prevention of progression to invasive cutaneous squamous cell carcinoma. Full article

Six novel pyrazole-based carbohydrazone derivatives (3a–3f) bearing structurally diverse heteroaromatic substituents were synthesized and characterized by ATR-FTIR, ¹H NMR, APT-¹³C NMR, and HRMS analyses. Their multifunctional bioactivity was evaluated using antioxidant, photoprotective, CT-DNA-associated spectroscopic response, cytotoxicity, and scratch wound closure assays. Antioxidant activity was assessed by DPPH radical scavenging, Fe²⁺ chelation, and ferric thiocyanate (FTC) assays against appropriate reference standards, while photoprotective potential was determined by spectrophotometric SPF analysis using carrot seed oil as a reference. The benzothiazole-containing derivative (3f) showed the strongest DPPH scavenging activity, FTC antioxidant capacity, and photoprotective activity, while also producing one of the most pronounced CT-DNA-associated spectroscopic responses under the experimental conditions employed. In contrast, the benzimidazole derivative (3e) displayed the highest Fe²⁺ chelating activity among the synthesized compounds. In cell-based assays, the imidazole- and thiazole-containing derivatives (3b and 3c) showed the most favorable balance between growth-inhibitory potency and selectivity toward A431 epidermoid carcinoma cells relative to HaCaT keratinocytes. Scratch assay results did not support direct anti-migratory activity under the tested conditions but indicated compound-dependent modulation of wound-closure-associated cellular responses. Overall, these findings demonstrate that heteroaromatic substitution strongly modulates redox behavior, CT-DNA-associated spectroscopic behavior, photophysical properties, and cytotoxic selectivity in pyrazole-based carbohydrazones, identifying this scaffold as a structurally tunable platform for further bioactivity optimization. Full article

Nicotinamide (NAM), the amide form of vitamin B3, has gained increasing attention in dermatology due to its potential role in both skin aging and non-melanoma skin cancer (NMSC) prevention. This review summarizes the biological rationale and current clinical evidence supporting the use of NAM and other NAD⁺ precursors in photoaging and cutaneous carcinogenesis. Chronic ultraviolet exposure induces DNA damage, oxidative stress, inflammation, immune dysregulation, and extracellular matrix remodeling, linking photoaged skin to increased susceptibility to actinic keratoses (AKs), squamous cell carcinoma (SCCs), and basal cell carcinoma (BCCs). Through the NAD⁺ salvage pathway, NAM contributes to the maintenance of intracellular NAD⁺ pools, thereby influencing energy metabolism, DNA repair, mitochondrial function, redox homeostasis, and the activity of NAD⁺-dependent enzymes. Preclinical studies indicate that NAM enhances DNA repair, reduces oxidative stress and inflammatory signaling, supports autophagy and mitophagy, and improves epidermal barrier function and extracellular matrix integrity. Clinically, the strongest evidence for anti-aging effects concerns topical NAM, which consistently improves wrinkles, texture irregularities, pigmentation, and barrier function. Oral NAM has demonstrated chemopreventive activity in high-risk patients with previous NMSC, particularly by reducing the incidence of new SCCs and AKs during active treatment. However, despite a strong mechanistic rationale, current evidence remains heterogeneous, and additional long-term, skin-focused clinical trials are needed to better define efficacy, safety, optimal dosing strategies, and patient selection. Full article

Background/Objectives: Keratinocyte carcinomas (KCs), including squamous cell carcinomas (SCCs) and basal cell carcinomas (BCCs), are the most common malignancies worldwide. Accurate delineation of surgical margins is essential to ensure oncological control while preserving favourable aesthetic outcomes. Optical coherence tomography (OCT) is a non-invasive, real-time, high-resolution technique that may facilitate preoperative and intraoperative margin assessment. This systematic review aims to analyse existing evidence on the use of in vivo OCT in the assessment of surgical margins in KC. Methods: This systematic review was conducted in accordance with the PRISMA guidelines. The articles included were retrieved from the PubMed, Web of Science, Scopus and EBSCO databases. The search was limited to studies published between 2010 and November 2025. The inclusion criteria were the application of in vivo OCT as an adjunctive method in the surgical excision of KC. A total of 11 studies involving 303 patients met the inclusion criteria. OCT was used preoperatively, intraoperatively, combined pre- and intraoperatively and both pre-, intra- and postoperatively, with most studies focused on margin delineation by itself. Results: Agreement between OCT and histopathology ranges from 84% to 95.5%. Surgical benefits were observed in both conventional surgery and Mohs micrographic surgery, including reduction in MMS stages (1.89 to 1.23), fewer stages required, and narrower excision margins. Conclusions: Based on data analysis, it may be assumed that in vivo OCT may have potential in non-invasive margin assessment in the surgical treatment of KC. The available evidence is limited by the heterogeneity of protocols and devices and variability between lesion types, as well as the small sample sizes and limited comparability. Further research should focus on randomised multicentre trials involving large cohorts, cost–benefit analysis and evaluation of operator-dependent variability. Full article

Accounting for over 1.2 million new diagnoses worldwide in 2022, non-melanoma skin cancer (NMSC) represents the most common human cancer, predominantly manifesting as basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). NMSC serves as a powerful natural model for studying how environmental exposure, the exposome, reprograms the epigenome to drive carcinogenesis. Chronic ultraviolet radiation (UVR), the dominant risk factor, induces DNA damage and inflammation that dysregulate epigenetic enzymes (e.g., DNMTs, HDACs). These effects are layered with perturbations from β-HPV infection and cutaneous dysbiosis, altering DNA methylation, histone modifications, and non-coding RNA and miRNA expression in a multistep carcinogenic process. This review synthesizes the central role of epigenetic regulation as the critical interface between genetic susceptibility and cumulative exposome factors in NMSC pathogenesis. We integrate how UVR, HPV, and inflammation converge to remodel the keratinocyte epigenome. Finally, we evaluate the translational potential of this knowledge for refined risk stratification through epigenetic biomarkers and discuss emerging therapeutic strategies, including epidrugs, that target these dysregulated pathways for advanced NMSC management. Full article

Cluster of Differentiation 47 (CD47) functions as a key “don’t-eat-me” signal that enables cancer cells to evade macrophage-mediated immune clearance. GV1001, a 16-amino-acid peptide derived from human telomerase reverse transcriptase (hTERT), has been reported to exhibit antitumor and anti-inflammatory properties and to downregulate CD47 expression in human cells. In this study, we investigated whether GV1001 modulated CD47 expression and enhanced antitumor immunity in oral squamous cell carcinoma (OSCC). In vitro, GV1001 significantly reduced CD47 expression in both murine and human OSCC cells in dose- and time-dependent manners, resulting in a marked increase in macrophage-mediated phagocytosis. Mechanistically, GV1001 suppressed CD47 promoter activity and inhibited multiple upstream regulator expression in murine and human OSCC cell lines, while exerting minimal effects on normal human keratinocytes and fibroblasts. In vivo, GV1001 significantly inhibited tumor growth, suppressed CD47 expression, increased macrophage infiltration, and induced tumor cell necrosis and apoptosis in both murine OSCC syngeneic graft model and human OSCC xenograft model. GV1001 administered alone or in combination with cisplatin produced antitumor effects. Collectively, these findings demonstrate that GV1001 functions as a potent immunomodulatory anticancer peptide that downregulates CD47 expression and restores macrophage-mediated tumor clearance, highlighting its potential as a therapeutic strategy for OSCC. Full article

Cutaneous squamous cell carcinoma (cSCC) is the second most prevalent skin cancer diagnosed worldwide after basal cell carcinoma. CSCC represents a growing global public health challenge due to its higher potential of local invasion, recurrence, and metastasis. Incidence rates of cSCC are projected to increase due to rising exposures to risks factors. Ultraviolet light exposure is the primary cause, and lighter skin pigmentation, immunosuppressive conditions and skin phototype are the primary risk factors. CSCC typically presents as a red, scaly, flat lesion (in situ tumors) or a red, firm, raised lesion with scale or erosion (invasive tumors). Surgical excision remains the standard-of-care for localized cSCC and is often curative. Although, most patients achieve favorable outcomes, a subset of cSCC exhibits a highly aggressive and metastatic phenotype (postoperative recurrence rates are approximately 5%). Addressing the clinical challenge posed by these high-risk cases requires a more comprehensive understanding of the underlying molecular drivers. This review examines the interaction between transglutaminase 2 (TG2) and the G-protein-coupled receptor 56 (GPR56) as a pivotal driver of the aggressive cSCC phenotype. This molecular axis is particularly significant for its role in the maintenance of epidermal cancer stem (ECS) cells, which contribute to tumor progression and therapy resistance. While the definitive link between the TG2-GPR56 complex and systemic metastasis in cSCC is currently being elucidated, significant evidence from analogous malignancies and in vitro keratinocyte models provides a clear mechanistic roadmap for its involvement in tumor invasion. Full article

Background/Objectives: Oral squamous cell carcinoma (OSCC) is a major cause of human cancer. The enzyme, nicotinamide N-methyltransferase (NNMT), is overexpressed in a variety of human cancers, including OSCC. Our objective was to target NNMT with novel inhibitors and determine their anti-cancer efficacy while shedding light on their possible mechanism of action. Methods: We identified two small molecule inhibitors of NNMT (AG-670 and AO-022) based on a pharmacophore of the in silico nicotinamide binding site. These inhibitors were investigated for (i) potency to inhibit the activity of the isolated NNMT enzyme (EC₅₀ values), (ii) cytotoxicity (IC₅₀ values) against the human OSCC cell line, SCC-4, and (iii) ability to affect cellular energy metabolism, as measured by oxygen consumption, in SCC-4 cells (plus dysplastic oral keratinocytes (DOK) cells and breast cancer MCF-7 cells). Immunoblotting was used to determine whether NNMT was expressed in the aforementioned cells. Results: NNMT is expressed in SCC-4 and DOK cells (and primary human oral keratinocytes) but not MCF 7 cells. The NNMT inhibitors inhibit isolated NNMT enzyme activity and were cytotoxic to SCC-4 cells (EC₅₀ and IC₅₀ values in the micromolar range). Sublethal doses of the inhibitors were demonstrated to inhibit in situ mitochondrial oxygen consumption in SCC-4 and DOK cells but not in MCF-7 cells. It was demonstrated that the NNMT inhibitors do not directly inhibit mitochondrial electron transport chain activity. Thus, we deduce that the NNMT inhibitors affect mitochondrial activity indirectly via NNMT. Conclusions: It is concluded that NNMT is a potential drug target for oral cancer. Full article

Background/Objectives: The primary mechanisms driving UV-induced carcinogenesis include DNA damage leading to mutations, and reactive oxygen species (ROS) formation that can cause inflammation, immunosuppression, alteration of the structure of proteins, including transcription factors, and carcinogenesis through epigenetic modifications. Curcumin has the potential to inhibit DNA-methyltransferases (DNMTs) and histone deacetylases (HDACs), but this has not been examined yet at the gene-expression level. In this article, we aimed to explore the potential protective effect of curcumin against UV radiation-induced DNMT1, DNMT3A, DNMT3B, HDAC5, and HDAC6 expression in immortalized keratinocytes (HaCaT), hepatocellular carcinoma (HepG2), and lung adenocarcinoma (A549) cells. Methods: Cells were exposed to UV-B radiation for different periods and treated with curcumin at different concentrations to evaluate dose-related trends in DNMT and HDAC gene expression compared with untreated UV-exposed cells. Results: UV exposure increased the DNMT and HDAC gene expression levels in the examined cells dose-dependently. Curcumin exposure resulted in decreased mRNA expression levels of DNMT and HDAC gene expression. In our experimental setup curcumin modulated the transcription of DNMT and HDAC genes in A549 and HaCaT cells in a dose-dependent manner. In HepG2 cells, UV-B induced a less pronounced, but still significant, increase in the examined gene expression levels. This effect was also dose-dependently decreased by curcumin, although less markedly. Conclusions: Future studies are warranted to examine if curcumin combined with other chemopreventive agents through the HDAC and DNMT inhibitory activity at the gene expression level can exert a synergistic effect and may potentially supplement cancer therapeutic strategies. Full article

Background: Acquired epidermodysplasia verruciformis (AEV) is a rare cutaneous disorder arising in immunocompromised individuals. AEV is characterized by flat-topped, wart-like, or hypopigmented lesions predominantly on sun-exposed areas. Unlike classic genetic EV, AEV develops in the absence of germline mutations or family history. AEV most commonly arises in patients receiving iatrogenic immunosuppressive therapy for organ transplantation, autoimmune disease, or hematologic disorders. Methods: A comprehensive literature review was conducted via the PubMed database. Case reports and case series studies describing AEV in transplant and non-transplant iatrogenic immunosuppression were identified through a literature search. There were no restrictions on language or publication year. The last search was conducted in July 2025. Reports were analyzed for patient demographics, immunosuppressive agents, HPV subtypes, clinical and histopathologic features, and treatment outcomes. Results: AEV occurs across a broad spectrum of immunosuppressive therapies, including calcineurin inhibitors, antimetabolites, biologics, tyrosine kinase inhibitors, and cytotoxic chemotherapy. β-HPV subtypes, most commonly HPV 5 and 8, drive lesion formation in the context of impaired cell-mediated immunity. Histopathology demonstrates keratinocyte vacuolization, acanthosis, and perinuclear halos. Lesions may persist despite immunosuppressive adjustment, due to viral latency and incomplete immune reconstitution. Treatment strategies are varied and include topical retinoids, immune response modifiers, systemic retinoids, and HPV vaccination, and have variable efficacy. AEV carries an elevated risk of cutaneous squamous cell carcinoma, particularly in transplant recipients, and highlights the need for proactive dermatologic management. Conclusions: AEV represents a clinically significant consequence of immunosuppression mediated by β-HPV. Early recognition, monitoring for malignant transformation, and individualized multimodal therapy are critical. Future studies should evaluate targeted interventions to enhance antiviral immunity and establish standardized treatment guidelines. Full article

Background: Phenothiazine derivatives bearing trifluoromethyl substituents have attracted increasing interest as multifunctional scaffolds in drug repositioning strategies, particularly in cancer and infectious diseases. Structural modification of classical phenothiazines by incorporation of a quinoline moiety has previously been shown to enhance biological activity. Objectives: The present study aimed to develop an efficient synthesis of 8-trifluoromethylquinobenzothiazines and to evaluate the anticancer and antibacterial potential of their N-substituted analogues inspired by triflupromazine, trifluoperazine, and fluphenazine. Methods: 6H-8-Trifluoromethylquinobenzothiazine was synthesized by cyclization of 2-amino-4-trifluoromethylbenzenethiol and 3-bromo-2-chloroquinoline. The resulting quinobenzothiazine, unsubstituted at the nitrogen atom, was subjected to N-alkylation reactions to afford eleven new 6-dialkylaminoalkyl derivatives. Structural elucidation was performed using NMR and HRMS techniques. Anticancer activity was evaluated by MTT assay against human breast (MDA-MB-231), pancreatic (Mia-PaCa-2), and lung (A-549) carcinoma cell lines, as well as normal HaCaT keratinocytes. Antibacterial activity was assessed by MIC/MBC determination against selected Gram-positive and Gram-negative reference strains and clinical isolates. Results: Among the synthesized compounds, derivatives 8 and 12 exhibited the most favorable anticancer profiles, showing micromolar cytotoxicity (IC₅₀ ≈ 4–10 µM) against lung and pancreatic cancer cells combined with moderate selectivity toward cancer cells over normal keratinocytes. Compound 6 displayed lower cytotoxic potency but a notably high selectivity index due to minimal toxicity toward normal cells. In antibacterial assays, compound 3 exhibited activity against Gram-positive bacteria, including a methicillin-resistant Staphylococcus aureus isolate, with MIC values ranging from 7.8 to 15.6 µg/mL. The corresponding MBC values were equal to or twofold higher than the MICs (MBC/MIC = 1–2), fulfilling commonly accepted criteria for bactericidal activity (MBC/MIC ≤ 4). OD-based growth kinetics confirmed concentration-dependent inhibition of S. aureus growth. Conclusions: The obtained results identify 8-trifluoromethylquinobenzothiazines as a promising class of multifunctional compounds. Selected derivatives combine anticancer activity with acceptable selectivity or display potent antibacterial effects against clinically relevant Gram-positive pathogens. Full article

Aquaporins (AQPs) are a family of small integral membrane proteins that mediate the selective transport of water and, in some cases, small solutes such as glycerol and hydrogen peroxide. In the skin, distinct AQP isoforms are expressed throughout the epidermis, dermis, and hypodermis, where they play key roles in maintaining hydration, regulating keratinocyte and fibroblast proliferation, modulating inflammatory responses, and preserving overall tissue integrity. Increasing evidence indicates that aberrant AQP expression or function contributes to skin carcinogenesis, influencing tumor initiation, local invasion, metastasis, and responses to microenvironmental stress. Alterations in specific AQP isoforms have been associated with both major classes of cutaneous malignancies—non-melanoma skin cancers (NMSC), including basal cell carcinoma and squamous cell carcinoma, as well as malignant melanoma (MM)—yet their mechanistic contributions remain incompletely understood. This review synthesizes current knowledge on the involvement of each AQP isoform in skin cancer pathogenesis and progression, integrating findings from molecular, cellular, and in vivo studies. By clarifying the diverse roles of AQPs in cutaneous malignancies, this work aims to support the development of targeted interventions and guide future research in this rapidly evolving field. Full article

Epigenetic and stress-response pathways play central roles in cancer progression and represent attractive therapeutic targets. In this study, a series of dipyridothiazine–1,2,3-triazole hybrids bearing p-fluorophenyl and p-trifluoromethylphenyl substituents was synthesized via efficient dipolar cycloaddition reactions. Structural characterization was performed using ¹H, ¹³C, and ¹⁹F NMR spectroscopy and high-resolution mass spectrometry. Anticancer activity was evaluated using WST-1 and MTT assays against human cancer cell lines SNB-19 (glioblastoma), C32 (amelanotic melanoma), A549 (lung carcinoma), and MDA-MB-231 and MCF-7 (breast cancer), as well as normal HFF-1 fibroblasts and HaCaT keratinocytes, with doxorubicin and cisplatin as reference drugs. The hybrids TDT2b and TDT3b containing a p-trifluoromethylphenyl moiety showed the highest cytotoxicity and cancer cell selectivity. RT-qPCR analysis of H3, TP53, CDKN1A, BCL-2, and BAX expression for the lead compound TDT2b revealed modulation of chromatin organization, p53-dependent stress responses, apoptosis, and cell cycle regulation. Molecular docking studies with human histone deacetylase 6 (HDAC6) demonstrated favorable binding of TDT2b and TDT3b, supporting their role as potential epigenetic anticancer agents. Full article

Background/Objective: Human papillomavirus (HPV) represents the most widespread sexually transmitted infection globally, with high-risk strains such as HPV16 driving a rising incidence of oropharyngeal squamous cell carcinoma (OPSCC), particularly in developed countries like the United States and United Kingdom. In the U.S., HPV16-associated OPSCC has surpassed cervical cancer as the most common HPV-related malignancy. Despite the availability of preventive vaccines, uptake remains suboptimal among adolescents and shifting sexual behaviors have contributed to increased disease burden. Early detection remains a major clinical challenge due to the absence of defined precursor lesions and the extended latency between viral exposure and disease onset. Most patients present with advanced-stage disease and no prior clinical history of pre-malignancy, limiting access to early-stage samples and hindering biomarker discovery. Methods: To address these limitations, we developed an in vitro HPV16 oral cancer model, using the three-dimensional organotypic raft culture system that simulates the progression of HPV16-transfected oral epithelium from precancerous states to malignant phenotypes. Results: Using HPV16-transfected human tonsil keratinocytes, we generated stratified and differentiated epithelia that mimic the biochemical and structural changes observed in vivo. This system enables detailed monitoring of epithelial differentiation, biochemical shifts, viral genome status, and key oncogenic and metabolic markers associated with HPV16-driven OPSCC. By aligning expression profiles with clinical datasets, we validated the model through the measurement of virologic markers linked to infection and progression, as well as tissue markers indicative of carcinogenic transformation. Conclusions: This model offers a promising tool for refining early detection strategies and evaluating potential clinical biomarkers, ultimately aiming to improve diagnostic precision and therapeutic outcomes in HPV-associated OPSCC. Full article

Background: Skin cancer is the most common malignancy worldwide. Although photoprotection is the cornerstone of skin cancer prevention, evidence regarding the role of other radiations different from the ultraviolet radiation and the efficacy of sunscreens, oral supplements, DNA-repair enzymes, and antioxidants continues to evolve. Objectives: To review the current evidence on photoprotective strategies and assess their role in preventing actinic keratoses (AK), keratinocyte carcinomas and melanoma. Methods: A narrative review of the literature was conducted using PubMed (2010–2025), including studies in English and Spanish. Search terms comprised “photoprotection,” “sunscreen,” “oral photoprotection,” “skin cancer,” “melanoma,” “keratinocyte cancer,” “UV radiation,” “non-melanoma skin cancer” and related concepts. Articles were selected for clinical relevance. Results: Daily sunscreen use significantly reduces AK and cutaneous squamous cell carcinoma in high-risk individuals, although evidence for basal cell carcinoma and melanoma prevention remains heterogeneous. Balanced broad-spectrum protection, including UVA and visible light filtering, seems to be important, whereas high-energy visible light needs further investigation. DNA-repair enzymes have shown reductions in cyclobutane pyrimidine dimers and clinical improvement of AK. Antioxidants such as Polypodium leucotomos extract, topical and oral, exhibit preventive effects on actinic damage and carcinogenesis. Topical and especially oral nicotinamide demonstrate chemopreventive potential in immunocompetent patients. Vulnerable populations—including transplant recipients, XP patients, individuals with albinism, and outdoor workers—require tailored photoprotection strategies with demonstrated benefit. Conclusions: Photoprotection extends far beyond UV filters, encompassing biological ingredients, antioxidants, oral supplements, and broad-spectrum strategies that target the full exposome. Comprehensive, behaviour-based photoprotection programmes are essential for high-risk groups. Full article