Search Results (2,649)

Surface-enhanced Raman spectroscopy (SERS) amplifies Raman scattering by placing molecules in the near-field of plasmonic nanostructures, enabling label-free molecular fingerprinting. While attractive for living cell phenotyping, many cellular SERS works rely on internalized colloidal nanoparticles, leading to variable uptake/localization, aggregation-driven hotspot fluctuations, and potential cellular perturbation. Here, we report a chip-like Au/SiO₂ nanolaminate SERS substrate that supports direct culture and label-free measurements of living cells on spatially defined hotspots without nanoparticle uptake. The periodic nanolaminate forms dense nanogaps and is engineered for 785 nm excitation, providing uniform enhancement over a large, culture-compatible area with high hotspot uniformity. By engineering the cell–substrate nano–bio interface, the platform enables reproducible acquisition of intrinsic cellular vibrational fingerprints under physiological conditions without Raman tags. Using MCF-7 and MDA-MB-231 breast cancer cells, we collected hundreds of spectra per line, and MDA-MB-231 exhibited broader spectral variations, indicating greater heterogeneity. Principal component analysis and linear discriminant analysis achieved 99% classification accuracy for MCF-7 and MDA-MB-231, and bright-field imaging confirmed preserved adhesion and canonical morphologies. This chip-based, label-free living cell SERS platform enables scalable, nonperturbative phenotyping and may support rapid malignancy classification and treatment response screening across subtle cancer states. Full article

While artemisinin and its derivatives demonstrate broad antitumor potential, the stereochemical influence on the bioactivity of higher-order artemisinin assemblies remains inadequately characterized. Herein, we report the synthesis, chromatographic separation, and structural elucidation of four stereoisomeric artemisinin trimers, followed by systematic evaluation of their antitumor efficacy against MCF-7 and MDA-MB-231 breast cancer cell lines. All trimers exhibited potent cytotoxicity against MCF-7 cells (IC₅₀ < 0.09 μM), with trimer 6a (β, β, β) demonstrating robust antitumor activity in both in vitro and in vivo xenograft models. Remarkably, pronounced stereochemistry-dependent activity emerged against MDA-MB-231 cells: 6a displayed approximately 100-fold greater potency than 6b (β, β, α) and 6.6-fold superiority over gemcitabine. Mechanistic investigations revealed that 6a downregulates Cyclin D1, CDK4, and CDK6 expression, thereby inducing G0/G1 phase cell cycle arrest. These findings underscore the pivotal role of stereochemical configuration in modulating artemisinin trimer bioactivity and provide rational guidance for structure-based design of artemisinin-derived anticancer therapeutics. Full article

A series of 6-azaindole pyridinium derivatives were synthesized, structurally characterized, and evaluated for their antimicrobial (against Staphylococcus aureus, Escherichia coli, and Candida albicans) and anticancer properties (against NCI 60 panel). Hemocompatibility was evaluated using the hemolytic index, while ADME properties were estimated using in silico methods. Structure–activity relationship analysis indicated that para-substitution of the phenyl ring, particularly with halogen or methoxy groups, influences antimicrobial activity, selectivity toward Gram-positive bacteria, and hemocompatibility. Compounds 2b and 2c showed the most notable antimicrobial effects, including inhibition of microbial adhesion at hemocompatible concentrations. Compound 2b exhibited growth inhibition against cancer cells, showing 57% percent growth inhibition (PGI) against the MDA-MB-468 breast cancer cell line at 10 mM. Overall, these results highlight 6-azaindole pyridinium salts as a promising class of compounds for further investigation. Full article

Breast cancer remains a major global health challenge, requiring novel therapeutic strategies that can overcome drug resistance and improve treatment efficacy. This study investigates the synergistic antitumor effects of etoposide, a conventional chemotherapeutic agent, and resveratrol, a natural polyphenol with anticancer properties, in human breast cancer cell lines, with particular focus on their ability to activate the parthanatos cell death pathway. Using MCF-7 (estrogen receptor-positive) and MDA-MB-231 (triple-negative) breast cancer cells, we assessed cell viability via MTT assays and evaluated parthanatos activation through multiple complementary approaches including AIF translocation determined by subcellular fractionation, NAD+ depletion measurement, and gene expression analysis. Synergy was quantified using the Chou–Talalay method across multiple effect levels (ED50, ED75, ED90). To establish causality, Olaparib PARP inhibitor experiments were performed to confirm that PARP-1 hyperactivation is essential for the observed cytotoxic effects. The results demonstrated that the etoposide–resveratrol combination significantly enhanced cell death and inhibited proliferation compared to single-agent treatments, with combination index (CI) values indicating strong synergism (CI = 0.62–0.75 for MCF-7; CI = 0.58–0.71 for MDA-MB-231). This synergy was associated with robust parthanatos activation, evidenced by increased PARP-1 expression, AIF nuclear translocation confirmed by subcellular fractionation, and significant NAD+ depletion. Critically, Olaparib pre-treatment (3 µM) significantly rescued cells from combination-induced death, restored NAD+ levels to near-control values, and prevented AIF translocation, establishing a causal link between PARP-1 hyperactivation and parthanatos-mediated cytotoxicity. The combination also induced significant DNA fragmentation, elevated oxidative stress, and cell death with morphological features consistent with parthanatos, while caspase activity remained low, confirming caspase-independent cell death. These findings suggest that targeting parthanatos with etoposide and resveratrol could offer a promising therapeutic strategy for breast cancer, potentially overcoming resistance and improving efficacy. Further in vivo studies and clinical investigations are needed to validate these results and explore translational applications. Full article

The development of effective and trackable drug delivery systems remains a major challenge in anticancer therapy. In this study, we designed novel polysaccharide-based theranostic carriers using a yeast-shell (YC) framework, providing a biocompatible platform for intracellular drug delivery. For the first time, a chitosan–genipin bioconjugate was synthesized via a solvent-free, green mechanochemical method and applied as an outer coating to microcarriers encapsulating the anticancer drug 5-fluorouracil (5-FU) and the fluorescent dye phenosafranin. The resulting system enabled simultaneous fluorescence tracking and the controlled release of the chemotherapeutic agent. In vitro evaluation using the MDA-MB-231 triple-negative breast cancer cell line demonstrated that 5-FU retained its antiproliferative activity, while the carriers facilitate sustained intracellular delivery. These findings highlight the potential of YC-based polysaccharide carriers, surface- modified with chitosan–genipin to enhance hydrophilicity, as a versatile platform for anticancer therapy, combining biocompatibility, traceability, and controlled drug release. Full article

Background: Breast cancer (BC) remains the most prevalent malignancy among women worldwide, with one in eight at risk during their lifetime. Platinum-based chemotherapeutic drugs, despite of their binding to the DNA of cancer cells, are plagued by toxicity and resistance, necessitating the need for safer and more effective alternatives, such as organometallic complexes. Both synthetic organometallic complexes and natural compounds have attracted attention in this regard. Organotin(IV) complexes are promising chemotherapeutics due to their structural versatility and bioactivity, while vitamins such as Vitamin D (VD) and Vitamin E (VE) exhibit antiproliferative, anti-inflammatory, and antioxidant properties, making them valuable candidates for combination therapy. Methodology: In this study, six novel organotin(IV) dithiocarbamate complexes [LMe₃Sn (Complex 1), LBu₃Sn (Complex 2), LPh₃Sn (Complex 3), LMe₂SnCl (Complex 4), LBu₂SnCl (Complex 5), and L₂Me₂Sn (Complex 6), where L = (E)-4-styrylpiperazine-1-carbodithioate], were synthesized and characterized by FT-IR, ¹H-, ¹³C-NMR, and elemental analysis. Results: Structural studies confirmed penta- and hexacoordination geometries. In silico docking against six BC-related proteins identified Complexes 2 and 4 with both vitamins as promising candidates, exhibiting strong binding affinities, with stable interaction profiles. However, integration of pharmacokinetic, antioxidant, and anti-inflammatory analyses highlighted Complex 4 with both vitamins as the most potent candidate owing to its superior ADME characteristics and balanced biological properties. Subsequent in vitro assays confirmed these findings, as Complex 4 demonstrated strong cytotoxic activity against both MCF-7 (>1.16-fold) and MDA-MB-231 (>1.46-fold) cell lines, surpassing the efficacy of cisplatin. Remarkably, co-administration of VD or VE with Complex 4 further enhanced its anticancer potential, with Chou–Talalay combination index values < 1 (0.66–0.91) indicating a synergistic interaction. Conclusions: Collectively, these results identify Complex 4 as a promising lead compound, and its synergistic activity with natural vitamins may promote cell death, likely through apoptosis induction and modulation of oxidative stress, underscoring its potential as an effective and less toxic therapeutic strategy for breast cancer management. Full article

Background: Cancer is a major health concern that significantly impacts the global population. Selective chemotherapeutic delivery is needed to improve the efficacy of cancer therapy while minimizing side effects in healthy cells. This study investigated the potential of gold nanoclusters (AuNCs) functionalized with poly(amidoamine) dendrimers (PAMAM) and folic acid (FA) to selectively deliver doxorubicin (DOX) to cancer cells that express the folate receptor (FR). Methods: AuNC synthesis was confirmed via UV–visible and Fourier transform infrared spectroscopy, nanoparticle tracking analysis, and transmission electron microscopy. Folic acid (FA) was incorporated for cell surface receptor targeting, while the triphenylphosphonium cation (TPP⁺) was added to improve mitochondrial localization. Cytotoxicity (MTT), apoptosis, caspase 3/7, mitopotential, and oxidative stress assays were assessed using human MCF-7 (breast adenocarcinoma), HeLa (cervical carcinoma), Caco-2 (colon adenocarcinoma), MDA-MB-231 (epithelial breast cancer), and the embryonic kidney (HEK293) cells. Results: Favorable DOX loading (>78%), with more than 90% of the drug released at pH 4.5, was achieved. A dose-dependent increase in cytotoxicity was observed, with IC50 values lower in cancer cells than HEK293 cells, indicating selective toxicity and minimal off-target effects. Targeting nanocomplexes produced the best responses in the mitopotential, caspase, and oxidative stress assays in HeLa and MCF-7 cells. Conclusions: The improved cytotoxicity in cancer cells may be due to folate-receptor-mediated cellular uptake, as well as the mitochondrial uptake of TPP⁺ nanocomplexes. This highlighted the potential of the drug–AuNC nanocomplexes to limit systemic side effects, proposing a potential novel strategy for drug delivery to cancer cells. Full article

Background/Objectives: The F3 peptide, a tumor-homing peptide known to bind cell-surface nucleolin, is frequently employed as a targeting vector in cancer research. However, the impact of the modification site on its cellular binding properties has not been investigated yet. In this work, we aimed to design an improved F3-based radioconjugate by identifying the optimal conjugation site and establishing a protocol for its biological evaluation in vitro. To achieve this, we compared F3 peptide derivatives modified at their N- or C-termini with DOTA for complexation of indium-111 (¹¹¹In) for SPECT or Auger electron therapy or a fluorophore (FITC) for optical imaging. Methods: N-and C-terminal DOTA-modified F3 peptides were radiolabeled with indium-111 and compared for their in vitro stability in different physiologically relevant media. Suitable nucleolin-positive cell lines for further in vitro studies were identified by confocal microscopy of a FITC-labeled F3 peptide derivative. The radioconjugates were then investigated on MDA-MB-231 (breast cancer) and PC-3 (prostate cancer) cells for nucleolin-specific cell binding and uptake, and several parameters of the in vitro assays were varied to establish a suitable protocol. Results: In general, in vitro assays with F3 peptide conjugates are challenging, as the outcome depends on a number of experimental parameters, leading, in some cases, to varying results. In particular, the presence of Ca²⁺ and Mg²⁺ had a decisive impact on the results, likely because the metal ions compete with the binding of F3 conjugates to nucleolin. The C-terminal modified, ¹¹¹In-labeled F3 radioconjugate performed better than the N-terminal modified analog. While several parameters of the in vitro experiments were optimized, the overall cell uptake in vitro of radioactivity was still low (<2% of applied radioactivity). Conclusions: A standardized in vitro protocol for evaluating F3 peptide conjugates on cancer cells was established, revealing that the C-terminus is the preferred site for modification. Because the cellular uptake of the radiotracer was shown to likely not be sufficient for radiotracer development, further studies on the optimization of the F3 peptide conjugates, including structural modifications, are required. Full article

High-frequency proton therapy shows promise for breast cancer (BC) treatment. We previously showed that BC cells’ metastatic potential (MP) correlates with their nanoparticle (NP) uptake efficiency. MP is known to be associated with microenvironment stiffness and radiosensitivity. Here, proton beam-irradiated MCF-7 and MDA-MB-231 cells were assessed for NP uptake efficiency under stiff (plastic) or soft (fibrin gel) conditions. In a stiff microenvironment, control MDA-MB-231 cells internalized 1.35-fold more NPs than MCF-7 (p < 0.0017), with comparably low uptake in soft conditions. After proton beam irradiation at a dose of 6 Gy, in stiff conditions, MDA-MB-231 cells showed a 1.6-fold increase in NP internalization compared to non-treated MDA-MB-231 (p < 0.0001), while MCF-7 cells showed no change, leading to an overall 1.86-fold difference between proton-treated MDA-MB-231 and MCF-7 cells (p < 0.0001). In soft conditions, irradiated MDA-MB-231 retained a 1.47-fold higher uptake of NPs than MCF-7 cells (p < 0.0172), but this value was 1.7-fold lower (p < 0.0001) compared to non-irradiated MDA-MB-231 cells on stiff plastic. Hence, therapeutic strategies combining proton irradiation with targeting tumor microenvironment softening may reduce post-irradiation metastasis risk. Full article

Current efforts to improve photodynamic therapy focus on nanomaterials that integrate deep tissue imaging with efficient reactive oxygen species generation. Gold nanoclusters (Au NCs) are promising alternatives to conventional photosensitizers due to their effective ROS production and enhanced biocompatibility when stabilized by a protein corona. However, both photosensitizers and Au NCs are typically activated by ultraviolet or visible light, which cannot penetrate deeper into tissues and is limited to superficial applications. Here, we report a near-infrared (NIR)-activated photodynamic nanoplatform based on core–shell upconverting nanoparticles (UCNPs; NaGdF₄:Yb³⁺,Er³⁺@NaGdF₄:Yb³⁺,Nd³⁺), functionalized with a protein corona containing bovine serum albumin-stabilized Au NCs (BSA–Au NCs) and photosensitizer chlorin e6 (Ce6). Spectroscopic data confirmed the formation of the UCNP-BSA–Au-Ce6 nanoplatform and demonstrated 32% energy transfer efficiency from UCNPs to Ce6, resulting in efficient reactive oxygen species generation under 808 nm irradiation. Cellular experiments confirmed the effective internalization and optimal biocompatibility of the nanoplatform in human breast cancer and healthy cells. Upon irradiation at 808 nm, the nanoplatform significantly reduced the viability of MDA-MB-231 cancer cells. These findings indicate that the UCNP-BSA–Au-Ce6 nanoplatform couples NIR activation with enhanced singlet oxygen production, providing a multifunctional platform for deep tissue imaging and NIR-activated photodynamic therapy. Full article

Background: Breast cancer brain metastases (BCBM) lack effective treatments, contributing to breast cancer-related morbidity and mortality. Integrating translational animal models and advanced non-invasive imaging can accelerate the development of urgently needed therapies. Method: In this study, we developed an intracarotid method mimicking BCBM and compared it to the stereotactic model in terms of animal welfare, tumour establishment, and blood–brain barrier (BBB) permeability. BCBM was established through intracarotid or stereotactic inoculation of BT474 and MDA-MB-231.Luc2 cells in NMRI nude mice. We utilised magnetic resonance imaging (MRI) and bioluminescence imaging (BLI) to monitor tumour growth and BBB permeability, supported by fluorescent immunohistochemistry for validation. Finally, light sheet microscopy (LSM) was employed to visualise tumour establishment in intact brains. Results: Both inoculation methods achieved a survival rate > 70%, with animals recovering within a week post-surgery. MRI and BLI effectively visualised tumour growth with stereotactic implantation, resulting in single tumours, while intracarotid inoculation led to micro-seeding of up to seven tumours in one brain. Tumour growth was rapid and homogenous in the stereotactic model, whereas the intracarotid model exhibited slower, heterogenous growth. Notably, BBB permeability was significantly higher in small tumours in the stereotactic model when compared to the intracarotid model (p = 0.003). Ex vivo analyses validated these findings with the identification of multiple metastasis in the intracarotid model and single tumours in the stereotactic model. Conclusions: We developed an animal model that closely mimics BCBM, highlighting extravasation and micro-seeding while maintaining animal welfare. Our established imaging protocols enable longitudinal evaluations of BBB permeability and treatment response, creating a translational platform for testing novel anti-cancer therapies. Full article

Oleocanthal (OC), an anti-inflammatory and antioxidant phenolic compound exclusively found in extra virgin olive oil (EVOO), has emerged as a potential anticancer agent through multiple mechanisms of action, yet its impact on key processes such as cellular metabolism remains insufficiently characterized. Here, we investigated the metabolic and mitochondrial responses to OC across different breast cancer molecular subtypes. Triple-negative (MDA-MB-231) and luminal (MCF7, T47D) breast cancer cell lines were treated with OC to evaluate cell viability, cell cycle progression, metabolic enzyme expression, mitochondrial respiration, and mitochondrial network organization. OC responsiveness differed, being highest in MDA-MB-231 and lowest in T47D cells. Lactate dehydrogenase levels decreased in all cell lines, while mitochondrial response varied. MDA-MB-231 mitochondrial function was fully impaired, while MCF7 cells showed increased respiratory activity, with marked mitochondrial fragmentation, and T47D cells largely preserved mitochondrial integrity and function. Notably, the magnitude of OC effects correlated with MET expression, an established target of OC and a prognostic factor associated with reduced relapse-free survival within the triple-negative subtype. Collectively, these findings identify OC as a modulator of cancer cell metabolism and mitochondrial dynamics, with particular relevance in MET-high triple-negative breast cancers. Full article

Background/Objectives: There is a clear need for more options to control the progression of breast cancer and prevent the occurrence of breast cancer in minority populations that have a higher rate of mortality due to triple-negative breast cancer (TNBC) subtypes. Prevalent nutraceuticals such as Ashwagandha (also known as the Indian Winter Cherry) have anti-inflammatory and apoptotic capabilities, as well as the ability to inhibit cancer growth. The purpose of this study is to analyze the novel combination of withaferin A (derived from the Indian Winter Cherry and known to have histone deacetylase inhibition capabilities) and sodium butyrate (a short-chain fatty acid produced from the gut microbiome and known to have DNA methyltransferase inhibition capabilities) treatment on breast cancer-derived cell lines. There is a scientific gap of possible causality of decreasing breast cancer progression when treated with sodium butyrate and withaferin A. Methods: Two in vitro cell viability assays were utilized consisting of [MTT (4,5 Dimethylthiazol-2-yl)] and the neutral red assay to analyze the impact of treatment of compounds alone and in combination on breast cancer cells for 72 h. The Highest Single Agent (HSA) combination analysis was utilized to derive combination indexes for our breast cancer cell types. Protein and gene expression was investigated for Class 1 histone deacetylases, de novo DNA methyltransferase, the p65 subunit of NF-κB, and NFκB1. Lastly, DNA methyltransferase enzymatic activity was analyzed via the Epigentek DNMT Activity/Inhibition ELISA Easy Kit. Results: Through the cell viability assay [MTT (4,5 Dimethylthiazol-2-yl)], MCF−7, MDA−MB−231, and MDA−MB−157 cells were found to have a decrease in cell viability due to combinatorial treatment with withaferin A and sodium butyrate. Western blot results depicted a decrease in protein expression levels for DNA methyltransferases due to the administration of 2.5 mM sodium butyrate and 0.2 µM withaferin A alone and in combination for breast cancer cell lines MCF−7, MDA-MB-231, and MDA−MB−157. Additionally, the combination of these two components have successfully inhibited the progression of the NFκB1 gene within analysis through the quantitative polymerase chain reaction (qPCR). Conclusions: The novel combination of withaferin A and sodium butyrate have markedly reduced the progression of breast cancer-derived cell lines for cell viability, epigenetic DNMT gene expression, as well as inhibiting NFκB1 signaling on the gene expression level. Full article

Globally, breast cancer is one of the most prevalent tumors in women and remains a major concern due to its high mortality rate. Although treatment options for this disease have evolved over the years, there are still many cases of recurrence and metastasis. In this context, considering the importance of evaluating less aggressive and more efficient therapeutic alternatives to aid in the treatment of breast cancer, the present study critically discusses the cytotoxic effects of diterpenoids isolated from Croton species (Euphorbiaceae). The articles were retrieved from different databases, from the first report published in 2005 to October 2025. A total of 115 diterpenoids were isolated from 15 Croton species and investigated against different breast cancer cell lines (MDA-MB-231, MCF-7, and MDA-MB-468). These compounds mainly belong to the kaurane group (40%), followed by clerodane (14%), tigliane (12%), and abietane (10%). Of this total, only 25 compounds showed promising results (IC₅₀ = < 10 µM). The mechanisms of action of the compounds crokokaugenoid A, kongensin A, kongensin D, ent-16β,17α-dihydroxykaurane, and lauicyclone A have been reported. These compounds likely act by inducing apoptosis, autophagy, cell cycle arrest, inhibition of cell migration and invasion, and DNA fragmentation in breast cancer cell lines. To date, no randomized clinical trials have been conducted using Croton diterpenoids for the treatment of breast cancer. Therefore, further studies on the modulation of the immune response by these natural products are essential to better understand their immunotherapeutic activity in the tumor microenvironment during breast cancer progression. Full article

Triple-negative breast cancer (TNBC) cells with intact homologous recombination (HR) repair mechanism can survive treatment with Olaparib, which further limits the clinical application of PARP1/2 inhibitors. Previous studies have demonstrated that inhibition of indoleamine 2,3-dioxygenase (IDO) can enhance the sensitivity of human tumor cells to PARP1/2 inhibitors. However, the mechanisms underlying their synergistic effects in the treatment of TNBC remain unclear. Herein, we demonstrate that the combination of Olaparib and Epacadostat significantly reduces the proliferation of BRCA-proficient MDA-MB-231 and MDA-MB-468 cells compared to either monotherapy. Mechanistically, Epacadostat reduces intracellular kynurenine and NAD⁺ levels, thereby sensitizing TNBCs to PARP1/2 inhibition and significantly amplifying Olaparib-induced DNA damage. Furthermore, Epacadostat and Olaparib synergistically increase cellular reactive oxygen species (ROS), leading to DNA oxidative damage and apoptosis. In vivo, Epacadostat and Olaparib significantly suppressed MDA-MB-468 tumor growth compared to the monotherapy groups, while promoting an increase in phosphorylated H2AX. Notably, the dual inhibition of IDO1 and PARP1/2 specifically reduced the expression of HR core genes and proteins, such as BRCA1 and RAD51, which may contribute to impaired DNA-damage repair and increased sensitivity to Olaparib. In summary, targeting both IDO1 and PARP1/2 represents a promising combination therapy for BRCA-proficient TNBC. Full article