T47D Breast Cancer Cells Research Articles

Adaptation to cellular stresses entails an incompletely understood coordination of transcriptional and post-transcriptional gene expression programs. Here, by quantifying hypoxia-dependent transcriptomes, epigenomes and translatomes in T47D breast cancer cells and H9 human embryonic stem cells, we show pervasive changes in transcription start site (TSS) selection associated with nucleosome repositioning and alterations in H3K4me3 distribution. Notably, hypoxia-associated TSS switching was induced or reversed via pharmacological modulation of H3K4me3 in the absence of hypoxia, defining a role for H3K4me3 in TSS selection independent of HIF1-transcriptional programs. By remodelling 5'UTRs, TSS switching selectively alters protein synthesis, including enhanced translation of messenger RNAs encoding pyruvate dehydrogenase kinase 1, which is essential for metabolic adaptation to hypoxia. These results demonstrate a previously unappreciated mechanism of translational regulation during hypoxia driven by epigenetic reprogramming of the 5'UTRome.

C-type lectin-like domain family 2 (CLEC2D), a transmembrane protein, is a ligand for the inhibitory receptor CD161, which is expressed in several types of immune cells. CLEC2D expressed on cancer cells suppresses antitumor effect of these cells by interacting with CD161 in human malignancies. However, its clinical significance in breast cancer and its direct biological role in cancer cells remain largely unclear. In this study, we immunolocalized CLEC2D in 174 breast cancer tissues and correlated its immunoreactivity with clinicopathological parameters and clinical outcomes. Additionally, we conducted in vitro assays to examine the effects of CLEC2D on the proliferation and migration of breast cancer cell lines. CLEC2D immunoreactivity was predominantly detected in the cytoplasm of breast cancer cells and was associated with increased proliferation and invasion, as well as poor clinical outcomes especially in those who had received chemotherapy. In vitro experiments demonstrated that the knockdown of CLEC2D significantly suppressed the proliferation and migration of MCF-7, MDA-MB-231, T-47D breast cancer cells. We therefore concluded that CLED2D directly promoted breast cancer cell proliferation and migration independently of immune cells and served as a poor prognostic factor in breast cancer.

Nur77 inhibits mitochondrial excessive fragmentation through mutated p53 L194F in T47D breast cancer cells.

A bedside-to-bench translational analysis of NF1 alterations and CDK4/6 inhibitor resistance in hormone receptor-positive metastatic breast cancer.

The most common type of cancer in Indonesia is breast cancer. Anticancer medications made of natural ingredients are beginning to be produced. Methanol extract of young bay leaves (Eugenia polyantha) has anticancer activity at moderate levels. The compounds that function as anticancer are flavonoids. The duration and extraction technique can have an impact on how active chemicals are extracted from natural materials. Through variations in the duration of the extraction process for young bay leaves, this study seeks to ascertain the amounts of flavonoids and the cytotoxic activity of T47D breast cancer.Young bay leaf ethanol extract (EEDSM) was obtained using the Ultrasonic assisted extraction (UAE) method with 70% ethanol solvent and varying extraction times of 5, 15, and 25 minutes. EEDSM total flavonoid content was tested using the UV-visible spectrophotometric method with quercetin as a comparison. The cytotoxic test of the ethanol extract of young bay leaves was carried out using the MTT assay method. Determining the IC50 value uses linear regression and probit analysis. It will also use One Way ANOVA to quantitatively determine the significance of the difference between the effect of extraction time and the IC50 value on T47D breast cancer cells. The results showed that EEDSM with extraction times of 5, 15, and 25 minutes had total flavonoid levels of 2.13mgQE/g, 2.36mgQE/g, and 2.61mgQE/g and cytotoxic activity with an IC50 value of 843μg/mL; 1007μg/mL; and 735μg/mL. EEDSM 5 and 25 minutes were shown to have moderate levels of cytotoxic activity.

The Effect of Cowanin on ERK1/2 and p-ERK1/2 Protein Expression in T47D Breast Cancer Cells by The Western Blot Method

Nanoparticles (NPs) exhibit great promise in cancer diagnosis and treatment as drug carriers, imaging probes, and therapeutic agents. The surface ligands of NPs play a crucial role in determining their accumulation at the tumor site, thereby affecting the overall theranostic effectiveness. Here, we report a precise technique for the direct comparison of NP deposition within a singular tumor model by surface-enhanced Raman spectroscopy (SERS) encoding. We synthesized SERS-encoded NPs functionalized with diverse ligands (PEG for passive targeting and APTMUC1 or iRGD for active targeting, respectively) and administered a 1:1:1 mixture of the NPs to monolayer-cultured T47D breast cancer cells, 3D multicellular spheroids, and xenograft tumor-bearing mice. Through simultaneous localization and quantification of different NPs in the same tumor cell/spheroid/tissue section, we found that APTMUC1 incorporation could effectively enhance NP delivery in vitro (7.2× and 4.1× for T47D cells and spheroids, respectively, in comparison to the PEGylated NPs), albeit the active targeting efficacy was compromised for in vivo tumor delivery (1.4×). Modification with iRGD facilitated NP delivery with a lower efficiency (2.9×, 1.7×, and 1.1× for T47D cells, spheroids, and tumor tissue, respectively). The findings illustrate the effectiveness of employing the active targeting approach yet underscore the necessity for additional optimization of the NPs to surmount biological barriers in vivo despite successful active targeting observed in vitro. Moreover, this multicolor SERS-encoding technique can be further utilized to systematically explore the spatial distribution of NPs with diverse physiochemical attributes among different tissues and organs.

Artemisia serotina Bunge represents one of the endemic Artemisia L. species in flora of Central Asia. There is scant information on the phytochemistry and biological activity of this species. The aim of the present study was to analyze the chemical composition of essential oil from A. serotina (ASEO) growing in south Kazakhstan, together with the determination of its biological activity. ASEO isolation was carried out by hydrodistillation according to the State Pharmacopoeia of the Republic of Kazakhstan. Analysis of GC/MS data revealed that the most characteristic components of ASEO were irregular monoterpenes from three families: santolinane, artemisane, and lavandulane. The major compound was santolina alcohol (34.6%). Antimicrobial activity was studied against the reference bacterial and fungal strains using the recommended methods, allowing for an estimation of MIC (minimum inhibitory concentration). ASEO was most effective against Candida albicans (MIC = 2 mg/mL), exerting fungicidal activity. Thw MIC for bacterial species was higher, i.e., 4–16 mg/mL. Antiviral activity was tested against Coxsackievirus B3 (CVB3) and Human Herpesvirus type 1 (HHV-1) propagated in VERO cells. No antiviral effect against either virus was found at an ASEO concentration of 0.25 mg/mL, but a noticeable decrease in the intensity of HHV-1-related cytopathic effects was observed. Anticancer activity studies included several cancer cell lines. Cytotoxicity, cell cycle, thiol levels, and cell vitality were analyzed. Among the cancer cell lines tested, the breast cancer T47-D cell line exhibited the highest sensitivity to ASEO (IC50 = 40.81 ± 4.21 µg/mL at 24 h; IC50 = 33.17 ± 2.11 µg/mL at 48 h). The anticancer effect was suggested to be mainly due to the induction of cytostatic effects, accompanied by a disturbance of the intracellular redox balance. The obtained data provide novel information on the unique chemical composition of ASEO from south Kazakhstan, representing a new chemotype. Its bioactivity, including promising antifungal and anticancer properties, was demonstrated for the first time.

Breast cancer constitutes a growing global health crisis, with rising incidence and mortality alongside therapy-limiting adverse effects. Kombucha, a fermented beverage made from tea using a symbiotic culture of bacteria and yeast (SCOBY), has demonstrated various health-promoting properties. This study explores a novel substrate, Javanese turmeric (C. xanthorrhiza), an indigenous Indonesian herb known for its hepatoprotective, antioxidant, antidiabetic, and antimicrobial properties. The anti-cancer potential of Javanese turmeric kombucha (JTK) was evaluated as a complementary therapy against T47D cells by comparing its physicochemical and antioxidant properties with those of unfermented Javanese turmeric beverage (JTB), and assessing its cytotoxicity, morphological effects, and ability to induce apoptosis. Data were analyzed using analysis of variance (ANOVA), followed by post hoc tests such as Fisher’s method (α = 0.05). Statistical analyses were conducted using Minitab 17.0 programs. The results showed that JTK exhibited significantly higher levels of total phenols (162.61 ± 0.32 mgGAE/mL) and antioxidant activity (IC50 157.07 ± 2.75 ppm) compared to unfermented JTB. JTK also induced apoptosis in more than 22% of the T47D cell population, indicating a promising cytotoxic potential. The findings highlight that fermentation enhances the physicochemical characteristics and anti-cancer properties of Javanese turmeric, suggesting that kombucha derived from this plant may serve as a promising complementary beverage in breast cancer therapy. HIGHLIGHTS Kombucha was produced using Curcuma xanthorrhiza (Javanese turmeric) as a novel substrate. Javanese turmeric kombucha (JTK) exhibited higher total phenols, flavonoids, and antioxidant activity than the unfermented beverage. JTK induced apoptosis in over 22% of T47D breast cancer cells, as shown by Annexin V-FITC/PI staining and flow cytometry. This is the first report on the anti-cancer potential of JTK, emphasizing the role of fermentation in enhancing its bioactivity and supporting its promise as a complementary functional beverage for breast cancer therapy. GRAPHICAL ABSTRACT

DNA damage signaling requires functional interactions between 53BP1 and the wild-type p53 tumor suppressor. Cancer cells often express elevated levels of transcriptionally inactive mutant p53 (mtp53) that maintains MDM2 and MDMX (MDM4) binding partners. The ability of mtp53 to functionally interact with additional proteins in the context of a dynamic equilibrium with MDM2-MDMX heterodimers has not been described. Employing a stable isotope labeling in cell culture analysis in T47D breast cancer cells (expressing mtp53 L194F), we uncovered several chromatin-associated DNA replication and repair factors as MDM2-regulated phosphoproteins, including 53BP1. We used proximity ligation analysis in multiple breast cancer cell lines to confirm 53BP1-MDM2 complex formation. We demonstrated that a mtp53-MDM2/MDMX complex promoted 53BP1-MDC1 interactions by showing that mtp53-MDM2/MDMX complex disruptors, Nutlin 3a and ALRN-6924, reduced the 53BP1-MDC1 nuclear interactions (especially in S-phase). Surprisingly, these MDM2-driven MDC1-53BP1 interactions were not ATM dependent, suggesting distinct 53BP1-MDC1 complexes in response to genotoxic stress. We found that MDM2-deficient cells have increased poly-ADP-ribosylation on chromatin which supports the possibility that a mtp53-MDM2/MDMX pathway promotes aberrant DNA repair. Taken together, our data suggestthat a mtp53-MDM2/MDMX complex orchestrates DNA repair machinery activity on chromatin, thus priming cancer cells for persistent DNA damage repair (CPR).

Background: Cucumis melo a melon species, typically has a sweet taste. Some cultivars are known for their distinctive bitter flesh due to its higher levels of cucurbitacin. Cucurbitacin is semipolar compound that has anticancer properties. However, the anticancer effects of cucurbitacin from gama melon parfum (GMP) have not been widely studied. The use of n-Hexane as a non-polar solvent in GMP melon fractionation is to dissolve the non-polar parts of the plant. However, Cucurbitacin was found in the n-hexane fraction of Cucurbita pepo L. Therefore, this study will investigate the presence of Cucurbitacin in the n-Hexane fraction and its effects on breast cancer cells T47D and MCF7.Materials and methods: Dry simplicia of GMP melon fruit were macerated using methanol and fractionated using n-hexane. The presence of cucurbitacin was detected using the high-performance liquid chromatography (HPLC) method. Cell cytotoxicity tests were assessed using the MTT assay, with concentrations of 7.8125, 15.625, 31.25, 62.5, and 125 µg/mLResults: Cucurbitacin compounds were detected in the n-hexane fraction at a concentration of 7.6 µg/mL per 10 mg of n-hexane fraction. MCF7 cell viability was lower than that of T47D cells across all concentrations tested. MCF7 cell viability was below 50% at a concentration of 62.5 µg/mL. In contrast, T47D cell viability remained at 100% even at the highest concentration of 125 µg/mL. The IC50 value of MCF7 cells was 43.5 µg/mL.Conclusion: The cucurbitacin content in the n-Hexane fraction was 7.6 µg/mL per 10mg fraction. At this concentration, it moderately inhibits the proliferation of MCF7 cells.Keywords: gama melon parfum, cucurbitacin, HPLC, T47D, MCF7

To investigate the effect of downregulation of medium-chain acyl-coenzyme A dehydrogenase (ACADM) on invasion and migration of estrogen receptor-positive breast cancer cells and the underlying mechanism. The Kaplan-Meier Plotter database was used to analyze the ACADM expression levels in breast cancer and normal tissues and their association with patient prognosis. Human breast cancer MCF-7 and T47D cell lines with lentivirus-mediated ACADM knockdown were established, and their in situ tumor formation and metastasis after tail vein injection were evaluated in nude mice. The MCF-7 and T47D cells with ACADM knockdown and their unmodified parental cells were examined with oil-red O staining assay, ROS assay, mitochondrial respiratory chain function assay before and after treatments with ROS scavenger, Elamipretide (a cardiolipin oxidation inhibitor) or SC79 (an AKT activator), and the changes in migration and invasion abilities of the treated cells were analyzed with Transwell invasion assay and Boyden chamber assay. Western blotting was used to detect protein expression levels of related signaling pathways in the treated cells. ACADM overexpression was associated with a significantly shorter overall survival of breast cancer patients. In MCF-7 and T47D cells, ACADM knockdown resulted in downregulation of N calnexin, vimentin, p-P13K and p-AKT proteins, increased levels of free fatty acids and reactive oxygen species, lowered activities of mitochondrial respiratory chain complex III and V, and reduced mitochondrial inner phospholipids. ACADM knockdown significantly decreased the invasive capacity of the cells, which were obviously reversed by treatment with ROS scavenger, Elamipretide, and SC79. Down-regulation of ACADM inhibits migration and invasion ability of estrogen receptor-positive breast cancer cells by lowering lipotoxicity and impairing mitochondrial function through the ROS/PI3K/AKT pathway.

BackgroundSeveral mechanisms are involved in the resistance to endocrine therapy (ET) in estrogen receptor (ERα)-positive breast cancer (BC), including acquired mutations of ERα gene (ESR1). For example, the frequent mutation, Y537S, was shown to trigger a constitutively active receptor leading to reduced affinity for both agonist and antagonist ligands. The development of more comprehensive therapies remains a challenge in BC patients exhibiting activating mutations in ERα. Here, we show that Poly (ADP-ribose) polymerase-1 (PARP-1) may be considered as a novel therapeutic target in ERα-positive BC.MethodsERα wild type or Y537S mutated MCF7 and T47D BC cell lines were used as model systems. Immunoblotting, immunofluorescence, gene silencing, real-time PCR, promoter assays, chromatin immunoprecipitation sequencing (ChIP-seq) as well as cell viability, colony and cell cycle assays served to investigate the involvement of PARP-1 in BC progression. The growth of MCF7 ERα Y537S cells injected into the mammary ducts of NSG mice and treated with the ERα antagonist lasofoxifene or the PARP-1 inhibitor niraparib was monitored by luminescence imaging, weight measurement, and histological analysis. RNA sequencing studies were performed on the above-described xenograft tumors. METABRIC dataset was used to evaluate the clinical significance of PARP-1 and the biological role of the PARP-1-associated genes in ERα-positive BC patients.ResultsWe first demonstrated that the up-regulation of PARP-1 expression induced by estrogens is abrogated either by inhibiting or silencing ERα in MCF7 and T47D BC cells expressing ERα wild type or Y537S mutation. We then showed that PARP-1 is involved in the binding of ERα and its co-activator FoxA1 to the promoters of several target genes, as determined by ChIP-sequencing studies. Of note, the inhibition of PARP-1 prevented the proliferative effects mediated by ERα in BC cells expressing either wild type or Y537S ERα. In accordance with these findings, the growth of xenograft tumors derived from MCF7 ERα Y537S BC cells was significantly reduced using niraparib and lasofoxifene. Finally, RNA-sequencing analyses showed that ERα signaling is downregulated by niraparib compared to vehicle-treated tumors.ConclusionsOverall, our results suggest that PARP-1 should be explored as a potential target in comprehensive therapeutic approaches in ET-resistant BC.

Abstract Objective: Tumor growth requires a large amount of energy supply. If the energy supply can be blocked, the progress of the tumor can be slowed down or even killed. Warburg effect, which is highly dependent on glycolysis, in a variety of malignant tumors, including breast cancer. The Warburg effect limits the treatment targeting oxidative phosphorylation (OXPHOS) in breast cancer. There is an urgent need to explore new pathways and inhibitors for energy metabolism and clarify their specific mechanisms. Our team has previously found that glycolysis and OXPHOS pathways are higher in breast cancer than in normal tissues, and the antibiotic Tigecycline (Tige) may inhibit both pathways. However, whether the decreased energy metabolism changes the proliferation, invasion, migration, and other phenotypes of breast cancer needs to be further verified, and whether there are clear specific targets involved in the energy regulation process also needs to be further explored. Methods: Bioinformatics analysis, immunohistochemistry (IHC), Western Blot (WB), glucose and lactate assays, and Seahorse energy metabolism assays were used to identify OXPHOS and glycolysis in breast cancer clinical samples and multiple cell energy knockdown models. Electron microscopy, JC1, and reactive oxygen species (ROS) fluorescence detection were used to determine the mitochondrial morphology, membrane potential, and ROS in the cells after energy metabolism down-regulation. Triple-negative breast cancer MB231 and MB468 cells and estrogen receptor-positive breast cancer MCF7 and T47D cells were treated with Tige at different concentrations for different times. CCK8 assay, colony formation assay, Edu fluorescence detection, and sphere formation assay were used to evaluate the effects of Tige on proliferation and tumor stemness in vitro. Nude mice xenograft tumor model and organoid culture were used to verify the phenotypes in vitro. Wound healing and Transwell assay were used to detect cell migration and invasion. RT-PCR and Western blot were used to detect the expression of multiple rate-limiting enzymes and other pathway markers in glucose metabolism pathways. RNA sequencing was used to explore the differentially expressed genes, analyze the related pathways, and identify the targets. Computer drug structure simulation was used to explore the binding domain between Tige and target genes. Lentiviral transfection was used to knock down and over-express the target gene, and the above phenotype and pathway exploration were repeated to prove the role of the target gene. Results: TCGA database, IHC, WB, and Seahorse analysis of clinical specimens all showed that OXPHOS and glycolysis were more active in breast cancer than in normal tissues. Electron microscopic observations revealed alterations in the structure of mitochondrial cristae. Respiratory chain complex proteins and membrane potential of mitochondria were affected, and intracellular ROS production was increased after the energy decreased. After the down-regulation of energy metabolism, the proliferation, invasion, and migration of breast cancer cells were affected, which was mainly due to the arrest of the S phase of cell cycle, which requires a large amount of energy supply. In vivo experiments using organoids have also obtained consistent results. The key enzymes of glucose metabolism in four breast cancer cell lines showed inconsistent decreases after Tige treatment. WB showed that in addition to the glucose metabolism pathway, the PI3K/AKT/mTOR pathway was also significantly inhibited. Bioinformatics analysis showed that the differentially expressed genes were mainly related to the inhibition of cell cycle, and the clear target may be PPFIA4. After changing the expression of PPFIA4, the rescue experiments in vivo and in vitro confirmed that PPFIA4 was involved in the energy metabolism of breast tumors. Conclusion: Both glycolysis and OXPHOS pathways are more active in breast tumors than in normal tissues. Tige treatment can successfully establish the down-regulated energy metabolism model of breast cancer and successfully inhibit the progression of breast cancer in vitro and in vivo. PPFIA4 may be involved in the regulation of PI3K/AKT/mTOR pathway and energy metabolism, which is worthy of further attention. At the same time, it also provides more theoretical support for expanding the clinical application of Tige. Citation Format: Haochen Yu, Lingfeng Tang, Jihan Qiu, Shengchun Liu. PPFIA4 mediates glucose metabolism reprogramming to alter the biological characteristics of breast cancer [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2024; 2024 Dec 10-13; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2025;31(12 Suppl):Abstract nr P5-01-24.

Abstract The addition of a CDK4/6 inhibitor (CDK4/6i) to endocrine therapy (ET) in patients with hormone receptor positive (HR+) advanced breast cancer (ABC) showed significant improvement in progression free survival (PFS) in pivotal trials. Three CDK4/6i; ribociclib, palbociclib and abemaciclib, have now been approved by global regulatory authorities, including the FDA, in this setting, leading to an improvement in patient outcomes over recent years. Unfortunately, tumours are resistant or develop resistance to these combinations, demonstrating a current unmet need for treatment regimens that can delay resistance and extend the time on 1st line therapy. This is particularly important due to shorter PFS in 2nd line. Camizestrant is a next generation oral selective estrogen receptor degrader (ngSERD) and pure ER antagonist that has demonstrated superior activity to fulvestrant both pre-clinically and clinically. A major mechanism of resistance to current ETs is the emergence of ESR1 mutations (ESR1m) which occur in ∼40% of patients after 1L therapy for metastatic disease. Camizestrant can degrade and antagonize both wild type and mutant forms of ER and delivers similar PFS in patients with or without detectable ESR1m at baseline. Therefore, camizestrant has the potential to become the backbone ET of choice. We investigated the effect of combining camizestrant with the three globally approved CDK4/6i, palbociclib, abemaciclib or ribociclib in vitro and in vivo. Addition of camizestrant enhanced the growth inhibitory effects of all three CDK4/6i in the ER+ breast cancer cell lines, MCF7 and T47D, as well as in MCF7 cells engineered to express ESR1m (Y537S). Analysis of the response of downstream signalling biomarkers to the combination revealed that camizestrant limits the induction of cyclin D1 caused by CDK4/6i monotherapy treatment and enhances the reduction of pRB, a key regulator of the cell cycle. Consistent with this, the combination with camizestrant enhanced G1 arrest at lower doses of CDK4/6i. This combination benefit was also explored in vivo across a panel of 7 ER+ breast PDX models where the combination of camizestrant plus the CDK4/6i was well tolerated. In four of these models the addition of palbociclib, abemaciclib or ribociclib significantly enhanced the tumour growth inhibition (TGI) of camizestrant. For example, in ST1799PBR, monotherapy camizestrant delivered 60% TGI whereas the addition of palbociclib, abemaciclib or ribociclib drove 78, 89 and 76% TGI, respectively. Combination benefit was achieved in ESR1wt as well as ESR1m models and with no difference in anti-tumour activity between the CDK4/6i partners. These preclinical data demonstrate consistent activity of camizestrant in combination with all three globally approved CDK4/6i. This, together with the efficacy of camizestrant in patients with ESR1wt and ESR1m tumours, suggests camizestrant in combination with CDK4/6i has the potential to provide extended benefit for patients with ER+/HER2 metastatic breast cancer in the first line setting, a concept under clinical investigation in the ongoing SERENA-6 (NCT04964934) and SERENA-4 (NCT04711252) studies. Citation Format: Susana Ros, Andrew Waddell, Sladjana Gagrica, Mandy Lawson, Alison Peter, Sophie D’Arcy, Mahreen Adil, Pablo Morentin Gutierrez, Ana Quiroga, Teresa Klinowska, Claire Crafter. The addition of ribociclib, palbociclib or abemaciclib to the next generation oral SERD, camizestrant, delivers greater anti-tumour efficacy in a range of ESR1wt and ESR1m breast PDX models [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2024; 2024 Dec 10-13; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2025;31(12 Suppl):Abstract nr P5-06-17.

1083 Background: Resistance to endocrine therapy (ET) in breast cancer (BC) patients is frequently associated with acquired ESR1 gene mutations like the Y537S, which triggers a constitutive estrogen receptor (ERα) activation. Therefore, the identification of novel therapeutic strategies is crucial for the management of ER-positive, ET-resistant BC. In this context, PARP1 poly(ADP-ribose) polymerase 1 (PARP-1) has emerged as a promising therapeutic target, based on its involvement in the regulation of oxidative DNA damage in BC cells. Methods: Data from the METABRIC dataset were used to assess the clinical relevance of PARP-1 in ER-positive BC patients. As experimental models, MCF7 and T47D BC cell lines expressing ERα wild type (wt) or Y537S mutation were used. PARP-1 regulation was investigated by western blotting, immunofluorescence, and chromatin immunoprecipitation (ChIP) assays. Gene expression, promoter assays, and chromatin immunoprecipitation sequencing (ChIP-seq) studies allowed us to analyze the transcriptional activity mediated by ERα. Cell cycle, proliferation and colony formation experiments as well as in vivo studies were performed to evaluate the biological effects of the PARP-1 inhibitor niraparib. Results: We observed that the up-regulation of PARP-1 upon exposure to 17β-estradiol (E 2 ) occurs through ERα in BC cells expressing either ERα wt or Y537S mutation. Moreover, we assessed that the transcriptional activity of ERα relies on PARP-1, as demonstrated by the ability of nirabarib to prevent the transactivation of ERα and the regulation of ERα target genes. In addition, niraparib halted the proliferation and cycle progression of BC cells expressing either ERα wt or Y537S mutation. Of note, niraparib suppressed primary tumor growth in xenograft tumors derived from ERα Y537S mutated MCF7 cells. Conclusions: Our data suggest that crosstalk between PARP-1 and ERα is involved in the proliferative responses of ERα wt or Y537S mutated BC cells. Therefore, targeting PARP-1 could provide a promising strategy to overcome the ET resistance of BC cells.

The advancement of drug delivery systems (DDSs) for controlled and targeted release needs further development to provide efficient cancer treatment. In this research, nanoliposomes (Lip) containing Cassia alata extract (CA) coated with chitosan-folate (Chi-FA) have been successfully synthesized as a DDS to breast cancer cells. Anticancer compounds were extracted from CA, and the effects of several parameters, such as ethanol concentration, ultrasonication time, and simplicia:solvent ratio, were analyzed using the response surface methodology (RSM). The successful conjugation of Chi-FA was observed using UV-Vis, FTIR, and XRD. The formation of Lip, CA-loaded nanoliposomes (Lip-CA), and Chi-FA coated Lip-CA (Lip-CA@Chi-FA) was validated using ATR-FTIR and TEM. Drug release studies show that nanoliposomes are selective in cancer cell conditions. The use of chitosan folate-conjugated nanoliposome encapsulation can deliver the extract more targeted to T47D breast cancer cells. The cytotoxicity test showed that Lip-CA@Chi-FA exhibited an IC₅₀ value of 53.46µg/mL against T47D cells, indicating moderate anticancer activity and improved delivery efficiency compared to non-encapsulated extract. In silico studies to predict pharmacokinetics and molecular docking simulations of the main compounds of CA support the experimental findings.

BackgroundThe endophytic fungus Diaporthe sp. GNBP-10 has been reported to produce metabolite bis-anthraquinone (+)-2,2′-epicytoskyrin A in high titers. In this study, we evaluated the potential of this metabolite as an anti-breast cancer agent by conducting antiproliferative activity studies against two breast cancer cell lines, MCF-7 and T47D.Materials and methodsThe antiproliferative activity of (+)-2,2′-epicytoskyrin A was determined by a 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay, fluorescence microscopy, and flow cytometry. In addition, the mode of action was assessed by several techniques, including the formation of apoptotic bodies using scanning electron microscopy (SEM) and the interaction or intercalation between (+)-2,2′-epicytoskyrin A with calf thymus DNA as indicated by the UV and 1H-NMR spectra. Moreover, molecular docking was also conducted.Results(+)-2,2′-Epicytoskyrin A exhibited significant antiproliferative effects against MCF-7 and T47D cells. The half-maximal inhibitory concentration (IC50) values for MCF-7 and T47D cells were 50.77 ± 33.23 µM and 36.24 ± 12.57 µM, respectively. (+)-2,2′-Epicytoskyrin A induced cancer cell death and promoted the formation of apoptotic bodies in both cell lines. These phenomena were expected to be facilitated by the DNA-binding ability of hydrogen atoms contained in (+)-2,2′-epicytoskyrin A. Molecular docking data indicated that (+)-2,2′-epicytoskyrin A might bind to the minor groove area of DNA, suggesting its potential as a DNA intercalator.ConclusionThis study highlighted the potential of (+)-2,2′-epicytoskyrin A as a promising candidate for future breast cancer treatment.Graphical abstract

Alantolactone, a bioactive sesquiterpene lactone derived from the roots of Inula helenium (elecampane), has garnered attention in biomedical and pharmacological research for its diverse therapeutic properties, including anticancer, anti-inflammatory, antimicrobial, and antioxidant activities. Despite its well-documented bioactivity, the effects of alantolactone on calcium ion (Ca2+) signaling and the underlying mechanisms in human breast cancer cells remain poorly understood. This study explored how alantolactone influences intracellular Ca2+ levels ([Ca2+]i), cell viability, and the role of Ca2+-dependent pathways in T-47D human breast cancer cells. Specifically, it examined the relationship between Ca2+ signaling and cytotoxicity in cells exposed to alantolactone, with or without the Ca2+ chelator BAPTA-AM. The findings reveal that alantolactone (25-75μM) increases [Ca2+]i in a concentration-dependent manner, while concentrations of 25-100μM induce cytotoxicity, an effect that can be reversed by BAPTA-AM pre-treatment. Removing extracellular Ca2+ significantly inhibits Ca2+ influx, and both SKF96365 and 2-APB, modulators of store-operated Ca2+ channels, block the alantolactone-induced Ca2+ entry. Additionally, in a Ca2+-free environment, thapsigargin, an inhibitor of the endoplasmic reticulum Ca2+ pump, suppresses the alantolactone-induced rise in [Ca2+]i, while alantolactone reduces the [Ca2+]i increase triggered by thapsigargin. Moreover, inhibiting phospholipase C (PLC) with U73122 abolishes the alantolactone-induced [Ca2+]i elevation. These results suggest that alantolactone-induced cell death in T-47D cells is Ca2+-dependent, involving Ca2+ entry via store-operated channels and Ca2+ release from the endoplasmic reticulum, with PLC playing a pivotal role. Importantly, the ability of BAPTA-AM to reverse alantolactone's cytotoxic effects highlights its potential therapeutic significance in breast cancer research.

Background: Breast cancer accounts for 30% of all new cancers diagnosed in women annually. Current evidence shows that 70-80% of newly diagnosed breast cancers are hormone sensitive, indicating that their growth is promoted by hormones such as progestins and estrogens. Progestins have been found to alter microRNA expression in cancer and various tissues in humans, potentially contributing to breast cancer progression and metastasis. Different progestins regulate specific microRNAs known to influence genes that promote cancer development and growth. Our initial computer-based analysis identified primiR-190 and primiR-199a-1 as potential targets for CD44 and vascular endothelial growth factor (VEGF), proteins essential in breast cancer growth. This study determined the effect of different progestins on transcriptional expression of primiR-190 and primiR-199a-1 in T47D breast cancer cells. Methods: Progesterone receptor (PR)-positive T47D breast cancer cells were exposed to the natural hormone, progesterone, and three synthetic progestins, medroxyprogesterone acetate, norgesterol, and norethindrone for 24 hours. Real-time PCR was used to determine the transcriptional expression of primiR-190 and primiR-199a-1. To confirm the role of PR-dependent pathways on expression of both primiR-190 and primiR-199a-1, we also tested the different progestins on a progesterone receptor (PR) negative cell line, T47Dco-Y. Results: Our results showed significantly increased transcriptional expression of primiR-190 and primiR-199a-1 in T47D breast cancer cells when exposed to progesterone and synthetic progestins. RU-486, a PR antagonist, suppressed progestin-induced expression of both primiR-190 and primiR-199a-1. We did not observe progestin-induced effects in the PR-negative cell line. These results suggest a direct involvement of PR-dependent pathways in regulation of these two microRNAs. This study also found no effect on expression of primiR-190 and primiR-199a-1 when T47D cells were exposed to 17β estradiol and DMSO providing further evidence that progestins exclusively regulate expression of these two microRNAs. Conclusion: We concluded that different progestins significantly increase transcriptional expression of primiR-190 and primiR-199a-1 through progesterone receptor-mediated pathways. Our results indicate that primiR-190 and primiR-199a-1 expression can be useful as biomarkers in some forms of PR-positive breast cancers. This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.