Search Results (2,805)

Although cryoablation of tumor tissue is known to induce systemic antitumor immune responses, the underlying mechanisms remain poorly understood, and therapeutic efficacy is often unpredictable. During cryoablation, the cryoprobe creates a temperature gradient, resulting in a central zone of lethal tissue destruction and a periphery characterized by sub-lethal injury. In this peripheral zone, cells undergo programmed cell death triggered by thermal shock and ischemia. A widely cited, yet debated, hypothesis suggests that these apoptotic events in the tumor periphery may suppress the antitumor immune response. The purpose of this study was to experimentally test this hypothesis. We utilized the murine breast cancer cell line (4T1-Luc) and a panel of human cell lines (MCF-7, BT-20, BT-474, MDA-MB-231, MDA-MB-453, HBL-100). Following validation via flow cytometry using Annexin V-AF488, Rhodamine 123, TMRE, PI, and 7-AAD, we established −7 °C and −80 °C as temperature conditions that predominantly induce apoptosis and necrosis, respectively. These conditions were used to prepare cryo-treated 4T1-Luc cells for the vaccination of syngeneic mice. Ten days post-immunization, the efficacy of the treatment was evaluated in subcutaneous solid tumor and lung metastasis models by monitoring tumor growth, quantifying tumor-specific antibodies, performing histological analysis of tumor and lung tissues, and quantifying lung metastases via PCR and luciferase assays. Contrary to the initial hypothesis, our findings demonstrate that tumor cells undergoing sub-lethal cryoablation do not acquire immunosuppressive characteristics. Instead, they promote systemic antitumor immunity. Although antitumor immunity induced by apoptotic and necrotic tumor cells was comparable in a subcutaneous tumor model, vaccination with necrotic tumor cells proved more effective than vaccination with apoptotic cells in controlling lung metastasis formation. Full article

Background/Objectives: Breast cancer exhibits substantial molecular heterogeneity, resulting in diverse therapeutic vulnerabilities and limiting the efficacy of single-agent therapies. Although multi-target strategies may offer improved therapeutic benefit, the systematic identification of synergistic higher-order target combinations remains challenging. This study aimed to identify and validate effective higher-order target combinations for heterogeneous breast cancer. Methods: DeepMDS, a previously developed deep learning-based multi-compound synergy prediction model, was used to prioritize candidate target combinations for breast cancer. Exhaustive two-target and three-target combinations were ranked in the gene-expression contexts of ER-positive luminal-like MCF-7 and triple-negative MDA-MB-231 breast cancer cells. The top-ranked target combinations were evaluated using single, pairwise, and triple small interfering RNA (siRNA) perturbations. Representative inhibitors were subsequently assessed in fixed-ratio combinations in MCF-7, MDA-MB-231, and 4T1 cells and in a 4T1 syngeneic mouse experiment. Results: BIRC5-NAMPT-TOP1 ranked first in both cell lines. Triple siRNA co-transfection targeting BIRC5, NAMPT, and TOP1 produced the strongest antiproliferative effects, with inhibition rates of 62.94% in MCF-7 cells and 55.62% in MDA-MB-231 cells. The corresponding inhibitors, LQZ-7I, FK866, and topotecan, exhibited synergistic antiproliferative activity at multiple molar ratios, with combination index values below 1. The optimized 2.5:10:1 molar ratio showed strong synergy in MCF-7, MDA-MB-231, and 4T1 cells, with combination index values of 0.26, 0.19, and 0.15, respectively. In tumor-bearing mice model, the triple-inhibitor regimen achieved a tumor inhibition rate of 62.05%. Topotecan-containing groups showed hematological alterations, whereas no statistically detectable elevations were observed in the measured terminal serum hepatic or renal biomarkers. Conclusions: The BIRC5-NAMPT-TOP1 combination showed reproducible phenotypic activity in the tested genetic and pharmacological models. These findings support the use of DeepMDS as a hypothesis-generation tool for higher-order target prioritization. Full article

Bovine leukemia virus (BLV), a major cause of B-cell lymphoma in cattle worldwide, has been linked to human breast cancer. Here, we performed comparative whole-transcriptome analysis of single clones of human epithelial 293T, breast cancer MCF7, and cervical cancer HeLa cells, stably infected with BLV, versus uninfected controls using RNA-sequencing technology. Differential expression analysis revealed 2050, 1314, and 2772 differentially expressed genes (DEGs) between BLV-infected 293T, MCF7, and HeLa cells and controls, respectively. Most DEGs were upregulated in BLV-infected 293T (76.5%) and MCF7 (69.1%) cells but downregulated in HeLa cells (62.0%). Functional enrichment analyses revealed enrichment of “Gene expression” and “Membrane Trafficking” pathways across all cell lines, and that of “Apoptosis” and “Axon guidance” pathways uniquely in 293T and MCF7 cells. Twenty genes linked to apoptosis of 293T and MCF7 cells were identified, and expression of 11 of these was confirmed using quantitative real-time PCR. The expression of EFEMP1 and LXN, which showed the greatest fold change, was validated: EFEMP1 knockdown and LXN overexpression inhibited cell proliferation, induced apoptosis, and altered growth morphology of 293T and MCF7 cells. This is the first transcriptome profiling of human cells during BLV latency, which should help understand the behavior of BLV. Full article

Triple-negative breast cancer (TNBC) remains a major therapeutic challenge due to pronounced molecular heterogeneity, transcriptional plasticity, and frequent treatment resistance. MicroRNA (miRNA)-based strategies have emerged as potential approaches for modulating dysregulated gene expression networks in TNBC; however, the contribution of understudied miRNA families to TNBC-associated regulatory programs remains incompletely understood. This study aimed to investigate the tumor-suppressive role of miR-548f-3p in TNBC and to identify candidate downstream effectors, with particular focus on ANP32E. An integrative analysis combining public transcriptomic datasets, clinical expression profiling, computational target prediction, network-based prioritization, pathway analysis, and single-cell transcriptomic assessment identified miR-548f-3p as consistently downregulated in TNBC. Among candidate downstream targets, ANP32E, a chromatin-associated regulator involved in H2A.Z histone variant dynamics, was identified as a potential effector exhibiting increased expression in TNBC and enrichment within malignant epithelial cell populations. An inverse association between miR-548f-3p and ANP32E expression was observed in patient-derived samples. In breast cancer cell models, miR-548f-3p mimic restoration increased apoptosis, promoted G₀/G₁ accumulation, and reduced migration- and invasion-associated readouts, although measurable effects were also observed in non-tumorigenic MCF-10A cells. These phenotypic changes were accompanied by reduced ANP32E expression at the protein level, indicating that ANP32E expression is responsive to miR-548f-3p restoration. This study supports miR-548f-3p as a candidate tumor-suppressive miRNA in TNBC. The reduction in ANP32E protein expression following miR-548f-3p restoration, together with computational, single-cell, and clinical expression evidence, supports ANP32E as an expression-responsive candidate downstream effector of miR-548f-3p. Further reporter-based and rescue experiments are required to confirm direct 3′UTR-mediated targeting and to define the mechanistic contribution of ANP32E within the broader miR-548f-3p regulatory network. Full article

Breast cancer cells exhibit a reversed pH gradient and metabolic plasticity that promote proliferation, invasion, and resistance to therapy. Natural products such as chlorogenic acid (CGA) and cinnamaldehyde (CA) have shown emerging anticancer potential. However, their effects on intracellular pH and metabolic transport systems remain undefined. Therefore, the aim of this study was to characterize these parameters in breast cancer and non-tumorigenic breast cells. This study evaluated the physiochemical properties of CGA and CA using LC–MS, under pH conditions (pH 1.2, 7.4, and 9.0) mimicking the gastrointestinal track (GIT). Additionally, LC–MS-based human liver microsome (HLM) assays with NADPH were used to evaluate susceptibility to CYP-mediated metabolism to evaluate first-pass metabolic stability. Intracellular uptake kinetics were quantified at multiple time points using LC–MS. Following CGA:CA treatment, intracellular pH (pH_i) was measured in cancerous MDA-MB-231 and non-tumorigenic MCF-10A breast cell lines using SNARF-1 targeted ratio-metric fluorescence approach. Expression of OATP1B1, GLUT1, and MCT1 were analyzed by Western and immunofluorescence respectively, to assess potential cellular uptake of CGA:CA through OATP1B1 and their effects on glucose uptake and lactate and proton transport. Physiochemical results demonstrated that the compounds ranged from fully stable (pH 1.2 and 7.4) to completely unstable (pH 9.0). HLM incubation indicated no CYP-mediated hepatic metabolism. Treatment results showed that there was rapid intracellular uptake of CGA and CA in cancer cells and that CGA:CA lowered pH_i in both MDA-MB-231 and MCF-7 cells, while pH_i remained mostly unchanged in MCF-10A cells. Protein analysis revealed that CGA:CA treatment downregulated GLUT1 and MCT1 expression in cancer cells, suggesting impaired glycolytic activity and lactate shuttling. OATP1B1 expression was significantly suppressed in cancer cells, suggesting feedback inhibition of the solute carrier protein. Collectively, these findings indicate that CGA and CA exhibit favorable biochemical stability and disrupt intracellular pH regulation and metabolic transporter expression in breast cancer cells. Importantly, normal cells are not significantly affected. Thus, CGA:CA demonstrates therapeutic potential for breast cancer through pH_i and metabolic modulation. Full article

Triple-negative breast cancer (TNBC) lacks effective targeted therapeutic strategies, and cisplatin resistance remains a major challenge in clinical treatment. This study aimed to investigate whether inorganic phosphate (Pi) influences cellular responses to cisplatin and to explore the potential molecular mechanisms involving RB1–E2F signaling, DNA repair regulation, and oxidative stress. Clinical associations between serum biochemical parameters and tumor histologic grade were evaluated in 246 patients with invasive ductal carcinoma. Triple-negative breast cancer cell line (MDA-MB-231), estrogen receptor-positive breast cancer cell line (MCF-7), and non-tumorigenic breast epithelial cell line (MCF-10A) were treated with control, Pi, cisplatin, or Pi combined with cisplatin.. Cellular proliferation, cell-cycle distribution, DNA damage, intracellular reactive oxygen species (ROS), inflammatory responses, and transcriptomic alterations were assessed using functional assays and RNA sequencing-based analyses. Pi levels showed an inverse association with tumor grade. In MDA-MB-231 cells, Pi combined with cisplatin resulted in enhanced growth inhibition, increased DNA damage accumulation, elevated cellular ROS production, and activation of inflammatory responses compared with cisplatin alone. Transcriptomic analyses revealed alterations in RB1–E2F-related transcriptional programs and reduced expression of DNA repair-associated gene sets. TCGA-BRCA analysis further indicated that elevated DNA repair pathway activity was associated with unfavorable survival outcomes. These findings suggest that Pi may modulate cisplatin responses through coordinated regulation of RB1–E2F signaling, DNA repair capacity, and oxidative stress responses, providing a potential mechanistic basis for further investigation of phosphate-associated therapeutic strategies in TNBC. Full article

Echinophora tenuifolia subsp. sibthorpiana is an aromatic and traditionally used plant whose phytochemical diversity and pharmacological potential remain incompletely characterized. This study aimed to integrate comprehensive chemical profiling with antioxidant, antimicrobial, and antiproliferative evaluations of an acidified methanolic extract prepared from its aerial parts. Phenolic constituents, volatile compounds, and fatty acids were characterized using LC–MS/MS, GC–MS, and GC–FID, respectively. Antioxidant capacity was assessed using DPPH and ABTS assays, antimicrobial effects were evaluated by disc diffusion and broth microdilution methods, and antiproliferative activity was investigated in six human cancer cell lines and non-cancerous BEAS-2B cells. Apoptosis induction and cell-cycle alterations were further examined by flow cytometry. The extract contained a high total phenolic content of 181.78 ± 5.03 mg GAE/g and exhibited substantial DPPH and ABTS radical scavenging activities of 333.65 ± 2.94 and 262.18 ± 6.80 mg TE/g, respectively. LC–MS/MS analysis identified rutin hydrate, quinic acid, chlorogenic acid, narcissin, and vicenin-2 as the predominant non-volatile constituents. The essential oil was dominated by methyl eugenol (51.10%) and Δ-3-carene (32.23%), whereas lauric acid (29.71%) was the major fatty acid. The extract also exhibited measurable antimicrobial activity and concentration-dependent cytotoxicity, with the greatest sensitivity observed in MCF-7 breast cancer cells (IC₅₀ = 32.96 ± 4.80 μg/mL), followed by A549 and MDA-MB-231 cells. However, the relatively close IC₅₀ values observed in cancer and non-cancerous BEAS-2B cells indicated limited cancer-cell selectivity under the tested conditions. Flow-cytometric analyses demonstrated marked apoptosis induction in MCF-7 cells, reaching 57.93 ± 1.80%, together with a cell-line-dependent accumulation in the G2/M phase. Collectively, these findings indicate that E. tenuifolia subsp. sibthorpiana is a chemically diverse source of plant-derived bioactive compounds with notable radical scavenging and measurable antimicrobial and cytotoxic effects. Further bioactivity-guided fractionation and mechanistic studies are required to identify the active constituents and clarify their pharmacological relevance and selectivity. Full article

To investigate the role and underlying mechanisms of TIMM8A in breast cancer progression. The expression of TIMM8A in breast cancer tissues and cell lines was assessed. Functional assays were performed to evaluate the effects of TIMM8A knockdown on proliferation, metastasis, and apoptosis in BT549 and MCF-7 cells. Co-immunoprecipitation (Co-IP) and ubiquitination assays were used to examine the interaction between TIMM8A and HSPA9, as well as the involvement of the E3 ubiquitin ligase RNF4. PI3K/AKT pathway activity was assessed by Western blotting. In vivo tumor growth was evaluated using a xenograft mouse model. TIMM8A was significantly upregulated in breast cancer tissues and cell lines, and high TIMM8A expression correlated with poor prognosis. TIMM8A knockdown suppressed proliferation and metastasis while inducing apoptosis in vitro. Mechanistically, TIMM8A interacted with HSPA9 and maintained its protein stability by inhibiting RNF4-mediated ubiquitination and degradation, thereby sustaining PI3K/AKT signaling activation. Conversely, TIMM8A depletion reduced HSPA9 stability and attenuated the pathway. Rescue experiments confirmed that HSPA9 overexpression restored PI3K/AKT activation and reversed TIMM8A-knockdown-induced malignant suppression. In vivo, TIMM8A silencing efficiently inhibited tumor growth, accompanied by reduced HSPA9 and Ki-67 expression and decreased PI3K/AKT phosphorylation. TIMM8A promotes breast cancer progression through the TIMM8A/HSPA9/PI3K/AKT regulatory axis, highlighting TIMM8A as a promising prognostic biomarker and potential therapeutic target for breast cancer. Full article

Lemur tail kinase 3 (LMTK3) is an oncogenic Ser/Thr kinase implicated in breast cancer (BC) progression, therapy resistance, and poor clinical outcomes, yet the molecular mechanisms governing its regulation remain poorly understood, particularly the role of its C-terminal intrinsically disordered region (IDR). Given that IDRs frequently harbour hidden structural motifs that control protein dynamics, we combined computational, biophysical, and biochemical approaches to systematically map regulatory elements within the LMTK3 C-terminus, identifying two regions (residues 688–1095 and 1181–1486) that interact with the LMTK3 kinase domain (LMTK3-KD). Characterisation of these interactions revealed that LMTK3^1181–1486 displays preferential binding to inactive wild-type LMTK3-KD over a constitutively active mutant (LMTK3-KD^L313R), a behaviour consistent with a potential autoinhibitory interaction. Guided by AlphaFold3 modelling, we localised this interaction primarily to a short α-helical motif (α-helix 2; residues 1247–1258) within the C-terminal IDR and subsequently identified Ser1258 within this motif as a candidate regulatory phosphorylation site, using [γ-³²P]-ATP kinase assays and mass spectrometry. Phosphorylation at Ser1258 altered interactions between α-helix 2 and the kinase domain, reducing binding to wild-type LMTK3-KD while increasing affinity for LMTK3-KD^L313R. Functionally, phospho-null mutation of Ser1258 impaired oestrogen receptor alpha (ERα) upregulation, proliferation, migration, and clonogenicity in ER-positive BC cell lines, and reduced tumour growth in female BALB/c nude mice bearing orthotopic MCF7 xenografts. Together, these findings identify a previously uncharacterised regulatory element within the LMTK3 C-terminus and support a model in which Ser1258 phosphorylation modulates kinase domain interactions and LMTK3-driven oncogenic functions in BC. Full article

Background/Objectives: Chronic inflammation in the tumor microenvironment (TME) promotes immune evasion and metastasis in breast cancer, where the IL-23/IL-17 axis is a key mediator. We investigated the expression of IL-23 in breast cancer and identified a small natural molecule therapeutically targeting this axis. Methods: IL-23 expression and its clinicopathological significance were assessed in a Moroccan breast cancer cohort and the METABRIC dataset. A High-throughput virtual screening of Allium sativum L. compounds was conducted to target the IL-23/IL-17 axis. In vitro, the selected candidate, IL-23RI, was evaluated for its effects on IL-17A and IFNγ production in human PBMCs using flow cytometry, as well as on the migration of MCF-7 and MDA-MB-231 breast cancer cells using wound-healing assays. Results: IL-23 was found to be overexpressed in aggressive breast cancer subtypes and correlated with unfavorable clinicopathological features and a poor prognosis. Elevated IL-23 expression was associated with an immunosuppressive TME, characterized by increased inhibitory immune checkpoints and immunosuppressive chemokines. In silico, IL-23RI demonstrates a high binding affinity for the IL-23 receptor, with a docking score of −7.482 kcal/mol and a binding free energy of −48.80 kcal/mol, stabilized by five hydrogen bonds. In vitro, IL-23RI selectively suppressed IL-17A production by CD4⁺ T cells without affecting IFNγ secretion by both CD4⁺ and CD8⁺ T cells. Furthermore, IL-23RI significantly inhibited the migration of MCF-7 and MDA-MB-231 breast cancer cells. Conclusions: These findings establish the IL-23/IL-17 axis as a critical therapeutic target and present IL-23RI as a promising dual-function agent for breast cancer treatment, concurrently modulating immunity and inhibiting tumor cell migration. Full article

Natural Killer (NK) cell-mediated immunosurveillance is a cornerstone of anti-tumor defense, yet its efficacy can be compromised by common clinical medications. Paracetamol (APAP) and metformin (MET) are widely used for pain and metabolic management in cancer patients, but their unintended effects on the immune–tumor interface remain poorly understood. MCF-7 breast cancer cells (Luminal A subtype) were treated with APAP or MET and co-cultured with primary expanded NK cells (CD3⁻CD56⁺CD16⁺). We evaluated cell proliferation, cell cycle distribution, and the enrichment of the CD44⁺CD24⁻ cancer stem-like cell (CSC-like) subpopulation. Transcriptional changes in immune checkpoints (PD-L1/L2), stress ligands (MICA/B), and costimulatory molecules CD80/86 were quantified via RT-qPCR. Despite inhibiting MCF-7 growth (IC₅₀ at 48 h: 11.86 mM for APAP; 21.11 mM for MET), both drugs induced a “therapeutic paradox” by promoting an immune-evasive phenotype. APAP and MET significantly enriched the CD44⁺CD24⁻ CSC-like subpopulation to 75.31% and 68.31%, respectively, compared to 11.00% in controls. Molecular analysis revealed a robust upregulation of PD-L1 (19.9-fold by APAP) and PD-L2 (16.4-fold by MET), alongside increased CD80/86 and MICA/B transcription. Consequently, drug-treated cells exhibited marked resistance to NK-mediated apoptosis and necrosis. NK cells preferentially eliminated non-stem cells (non-CSCs), inadvertently further concentrating the highly resistant CSC-like subpopulation. Additional experiments revealed that APAP directly impaired NK-cell survival and reduced the proportion of CD3⁻CD56⁺ cells, whereas MET exerted minimal effects on NK cells, suggesting distinct mechanisms underlying the observed reduction in NK-mediated cytotoxicity. Under the experimental conditions employed in this study, APAP and MET were associated with reduced susceptibility of MCF-7 cells to NK-mediated killing through distinct but partially overlapping mechanisms, including CSC-like enrichment and transcriptional activation of immune-evasion pathways. Although these findings were obtained in a mechanistic in vitro model using supra-physiological drug concentrations, they identify potential mechanisms that warrant further validation in physiologically relevant experimental systems and in vivo models. Full article

Background: As a key regulator of centrosome duplication, polo-like kinase 4 (PLK4) is abnormally overexpressed in various tumors and has emerged as an important target for the development of antitumor drugs. Methods: In this study, based on the lead compound ZSL-M001 (PLK4 IC50 = 3.0 μM) previously obtained by our research group, we designed and synthesized 28 novel quinazoline-based PLK4 inhibitors to enhance kinase inhibitory activity using side-chain extension strategies. Results: Among them, compound H24 (PLK4 IC50 < 0.1 nM) exhibited favorable in vitro antiproliferative activity against TRIM37-amplified MCF-7 breast cancer cells (MCF-7 IC50 = 2.37 ± 0.26 μM) and TRIM37-amplified neuroblastoma IMR-32 cells (IMR-32 IC50 = 1.28 ± 0.04 μM). Its activity was superior to that of the positive control LCR-263. Further in vitro biological evaluation demonstrated that H24 inhibited the colony formation of MCF-7 cells in a concentration-dependent manner, induced S/G2-phase cell-cycle arrest, and promoted apoptosis. H24 also showed favorable metabolic stability in human liver microsomes, with a half-life of 61.3 min. However, no obvious TRIM37 amplification-dependent cellular selectivity was observed in TRIM37 non-highly amplified A549 cells or normal human embryonic kidney HEK-293T cells. Given the suboptimal selectivity of the in vitro antiproliferative activity, Aurora kinase A, which shares high homology with PLK4, was selected for further evaluation of its selectivity. The IC50 for Aurora A inhibition was determined to be 151.2 nM, indicating that its broader kinase selectivity remains to be established. Conclusions: In summary, H24 is a highly potent biochemical PLK4 inhibitor and provides a useful lead scaffold for further optimization rather than a fully selective cellular candidate at the current stage. Full article

Background/Objectives: Benzimidazole and hydrazone scaffolds are widely investigated in anticancer drug discovery because of their structural versatility and capacity to interact with multiple cancer-related targets. This study aimed to synthesize a series of trifluoromethyl-substituted benzimidazole-hydrazone derivatives, evaluate their antiproliferative activity and cancer-cell selectivity, and explore their potential interactions with breast cancer-associated molecular targets. Methods: A series of benzimidazole-hydrazone derivatives were prepared through a four-step synthetic route using both conventional and microwave-assisted procedures. The structures of the synthesized compounds were characterized using spectroscopic and analytical methods. Antiproliferative activity was evaluated in estrogen receptor-positive MCF-7 human breast cancer cells using the MTT assay after 48 h of exposure. Selected active compounds were additionally tested against non-tumorigenic hTERT cells to determine their selectivity indices. In silico analyses were performed against estrogen receptor alpha in antagonist and selective estrogen receptor degrader conformations, bromodomain-containing protein 4, and the mTOR kinase domain. Results: Microwave irradiation substantially reduced reaction times from 12–24 h to 4–6 min and increased isolated yields by 7–24 percentage points compared with conventional conditions. Compounds 4, 7, 9, and 11 reduced MCF-7 cell viability below 50% at 20 μM. Compound 7 showed the highest antiproliferative activity, with an IC₅₀ value of 7.5 ± 0.8 μM, and the greatest selectivity toward MCF-7 cells over hTERT cells, with a selectivity index of 12.66. Molecular docking, MD simulation, and MM/GBSA calculations predicted that compound 7 would effectively bind to the investigated targets, particularly estrogen receptor alpha, as well as the BRD4 and mTOR kinase domains. Conclusions: Compound 7 represents a selective, mid-micromolar benzimidazole-hydrazone lead against MCF-7 breast cancer cells. Its predicted molecular interactions warrant further target-based, mechanistic, pharmacokinetic, and in vivo evaluation. Full article

Background: This study evaluates transdermal delivery of tamoxifen (TXN) as an alternative to the oral route of administration in treating breast cancer, which is the leading cause of cancer-related death in women globally. Oral TXN, a Class II drug, is associated with first-pass metabolism and serious side effects, including secondary cancers. Objectives: To enhance transdermal delivery, lipid-based transethosomes (TRS) were formulated using three different 2⁴ factorial designs with various non-ionic surfactants, including Tween 20^®, Span 20^®, and Span 80^®. Methods: Optimized TRS formulations were incorporated into HPMC-based gels and characterized for morphology, drug content, pH, viscosity, spreadability, ex vivo skin penetration, and deposition. Additionally, cytotoxicity and stability were assessed. Results: All TXN-TRS gels were suitable for transdermal use; however, Span 20^®-based TRS gel demonstrated the highest skin penetration (40.3 ± 1.5 µg/cm²), representing a 127-fold enhancement rate compared with the non-ethosomal TXN gel. In line with the enhanced penetration profile, cellular studies on MCF-7 cells showed concentration-dependent cytotoxicity, reaching 91.24 ± 1.01% inhibition at 2% w/w after 72 h, with an IC₅₀ value of 0.85 ± 0.02% w/w. Stability testing showed all formulations were more stable under refrigeration than at dry room temperature storage, supporting their potential as preclinical transdermal tamoxifen delivery platforms. Conclusions: Span 20^®-based TXN transethosomal gel markedly enhanced skin penetration while maintaining potent cytotoxic activity, supporting its further preclinical evaluation as a promising transdermal alternative to oral tamoxifen. Full article

Background/Objectives: Resveratrol (RSV) is a phenolic compound that possesses antioxidant properties and whose biological application has been limited by its physicochemical properties, including its low solubility and stability. Methods: In this study, polymeric nanoparticles (NPs) were developed using polylactic acid (PLA) to encapsulate resveratrol and improve its bioavailability, using a factorial design to optimize the formulation and evaluate its cytotoxicity against breast cancer cells. Results: The optimized system presented an average size of 389.2 nm, a PDI of 0.127, a negative z-potential, and an encapsulation efficiency of 76.02%. The statistical analysis indicated that the PLA: RSV ratio was the main determinant of encapsulation percentage and particle size (p < 0.05). On the other hand, with the hemolysis test, blood compatibility was evidenced at all concentrations evaluated, while in the cell assays, the PLA-RSV nanoparticles significantly decreased the cellular viability of MCF-7 and MDA-MB 231 cells compared to untreated cells, and in combination with NP PLA-RSV and doxorubicin, greater cytotoxicity was produced in MCF-7 cells compared to nanoparticle-only treatments (p < 0.05, ANOVA, via followed by a Fisher test). Conclusions: In addition, distinct cytotoxic effects are observed, associated with their tumor phenotype. Taken together, these results suggest that PLA-RSV NPs are a useful system for future studies on redox status and other biological processes important in cancer. Full article