T47D Breast Cancer Cells Research Articles

Modulation of Estrogen Receptor Alpha (ERα) and Tumor Suppressor Gene BRCA1 in Breast Cancer Cells by Bazedoxifene Acetate (BZA).

Selective estrogen receptor modulators (SERMs) are steroid analogs with dual functionality, acting as partial estrogen receptor agonists to preserve postmenopausal bone density and as estrogen receptor antagonists in breast tissue. Bazedoxifene acetate (BZA) is an FDA-approved, third-generation SERM used in the treatment of osteoporosis in women. It demonstrates potential as a therapeutic option for breast cancer patients undergoing endocrine therapy. Our study aimed to assess BZA's effects on Estrogen Receptor Alpha (ERα) and tumor suppressor gene BRCA1 in T-47D and MCF-7 breast cancer cells, using Western blots, cellular viability, apoptosis assays, and RT-qPCR. Cells were cultured in 5% charcoal-stripped fetal bovine serum for six days to deplete endogenous steroids. Following a 24 h exposure to 2 µM BZA (optimal concentration determined from 1 nM-2 µM studies), Western blot analyses revealed reduced ERα and BRCA1 protein levels in both cell lines. ERα decreased by 48-63% and BRCA1 by 61-64%, indicating sensitivity to antiestrogens. Cytolocalization of ERα and BRCA1 remained unchanged after BZA and 17-β-estradiol (E2) treatment. ESR1 mRNA expression correlated with Western blot findings. Image cytometric analysis using the stain, propidium iodide, detected decreased cellular proliferation in T-47D and MCF-7 cells following a 6-day treatment ranging from 1 nM to 2 µM BZA. BZA treatment alone led to a tenfold reduction in cellular proliferation compared to estrogen-treated cells, suggesting antiproliferative effects. Understanding BZA's modulation of BRCA1 and ERα, along with their mechanistic interactions, is vital for comprehending its impact on breast cancer tumor suppressors and hormone receptors.

Anticancer Activity Of Guava Leaf Extract (Psidium Guajava)

Free radicals are chemical compounds that are highly reactive and have the possibility of being detrimental to the body's cells. At high levels, free radicals can pose a serious risk to health, inflicting damage to major components of cells. Cell damage caused by free radicals, especially to Deoxyribonucleic Acid (DNA), can result in the development of cancer and other health problems. Guava seed leaves (Psidium guajava) are the focus of research because of their potential in reducing the growth of breast cancer cells. The study details the results of two literature review studies that support this claim. The bioactive compounds such as polyphenols, flavonoids, phenolic acids, and ascorbic acid found in guava seeds have been linked to antioxidant and anti-inflammatory properties. The first study by showed that guava leaf extract has anti-proliferative activity against breast cancer cells (MDA-MB-231 and MG-63). The second study highlighted the cytotoxic activity of 70% ethanol extract from guava leaves against T47D breast cancer cells. The results of both studies showed that guava seeds have the potential to inhibit the growth of breast cancer cells, indicating a possible role for guava seeds in breast cancer prevention strategies.

Abstract B040: Trispecific killer engagers against IGF1R and fetal form of insulin receptor induce human natural killer cell mediated killing of hormone receptor positive breast cancer in vitro and in vivo

Abstract Patients with hormone receptor-positive (HR+) breast cancers frequently recur with metastatic disease 5-20 years after the initial diagnosis and completion of chemotherapy and prolonged treatment with hormonal therapy. Thus, patients with metastatic HR+ breast cancer need new therapeutic options. A potential mechanism of therapeutic resistance in HR+ patients is the presence of slow-growing, well-differentiated cancer cells that result in clinically detectable metastases after a prolonged latency. One way to eliminate these cancer cells is with immunotherapy (IT). Unfortunately HR+ breast cancers have not responded to current T-cell based IT. The objective of this study is to target HR+ breast cancers using a natural killer (NK) cell based approach that targets cell surface receptors in HR+ breast cancer. The type I IGF receptor (IGF1R) is expressed on HR+ breast cancers and its expression is tightly related to ER function. Endocrine therapy resistance is associated with increased expression of the A-isoform or fetal form of IR (IR-A) and depend on IR signaling. We hypothesized that a drug that would target NK cells to IGF1R or IR-A expressing HR+ cells will be effective in killing them. We generated IGF1R or IR-A specific Tri specific Killer Engagers (TriKE) that leverage expression of IGF1R and IR-A on HR+ cells to cause NK directed death. The IGF1R TriKE consists of humanized single domain antibody (VHH) sequence of a CD16 nanobody to engage and activate NK cells, a humanized VHH of a nanobody against IGF1R to target HR+ breast cancer cells, and an IL-15 molecule between them to drive NK cell expansion and survival. The IGF1R TriKE did not bind embryonal fibroblasts from IGF1R knock out mice (R- cells) but bound R-/IGF1R cells (R- cells engineered to express human IGF1R) and to IGF1R+ MCF-7 and T47D breast cancer cells indicating specific binding to IGF1R on cells. It did not cause downregulation of IGF1R levels in multiple HR+ breast cancer cells and did not inhibit signaling via IGF1R. It specifically induced NK cell degranulation, measured by surface CD107a expression and intracellular IFNγ, against IGF1R+ target breast cancer cells (MCF-7, T-47D, ZR-75-1) in a functional assay compared to the anti-IGF1R nanobody. It did not induce degranulation of NK cells against IGF1R negative cells suggesting that the functionality was specific for IGF1R expressing targets. The IGF1R TriKE enhanced cell killing of HR+ breast cancer cells as measured by cytotoxicity assays. IGF1R TriKE combined with human NK cells inhibited tumor growth of MCF-7 tumors in NSG mice compared to control groups. Human NK cells persisted in peripheral blood three weeks after final NK infusion based on flow cytometry assessment. The IR-A TriKE incorporated a novel engineered non-immunoglobulin IR-A specific peptide binder. Our preliminary data show that the IR-A TriKE degranulated NK cells against breast cancer cells overexpressing IR-A. These data indicate that this strategy could be an effective treatment for HR+ metastatic breast cancer and make them responsive to IT. Citation Format: Courtney Baar, Emily Chiu, Yvette Soignier, Behiye Kodal, Jeffrey S Miller, Martin Felices, Deepali Sachdev. Trispecific killer engagers against IGF1R and fetal form of insulin receptor induce human natural killer cell mediated killing of hormone receptor positive breast cancer in vitro and in vivo [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Breast Cancer Research; 2023 Oct 19-22; San Diego, California. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_1):Abstract nr B040.

DMT1-dependent endosome-mitochondria interactions regulate mitochondrial iron translocation and metastatic outgrowth.

Transient early endosome (EE)-mitochondria interactions can mediate mitochondrial iron translocation, but the associated mechanisms are still elusive. We showed that Divalent Metal Transporter 1 (DMT1) sustains mitochondrial iron translocation via EE-mitochondria interactions in triple-negative MDA-MB-231, but not in luminal A T47D breast cancer cells. DMT1 silencing increases labile iron pool (LIP) levels and activates PINK1/Parkin-dependent mitophagy in MDA-MB-231 cells. Mitochondrial bioenergetics and the iron-associated protein profile were altered by DMT1 silencing and rescued by DMT1 re-expression. Transcriptomic profiles upon DMT1 silencing are strikingly different between 2D and 3D culture conditions, suggesting that the environment context is crucial for the DMT1 knockout phenotype observed in MDA-MB-231 cells. Lastly, in vivo lung metastasis assay revealed that DMT1 silencing promoted the outgrowth of lung metastatic nodules in both human and murine models of triple-negative breast cancer cells. These findings reveal a DMT1-dependent pathway connecting EE-mitochondria interactions to mitochondrial iron translocation and metastatic fitness of breast cancer cells.

Characterization of Nanoemulsion Non-Ionic and Cytotoxicity Test on T47d Cells Ethanol Fraction ofBarleria Prionitis L.

The formulation of the ethanol fraction of landep leaves identified bioactive compounds and evaluated anticancer activity on T47D breast cancer cells in vitro and was formulated as a nano emulsion to increase the solubility of drugs that are difficult to dissolve in water by increasing bioavailability. The aim of this research is to determine the anticancer activity and to characterize the Barleria prionitis ethanol fraction formulated in nano emulsion form and to determine the physical properties of the nano emulsion preparation. Landep leaf ethanol fraction nanoparticles were formulated with a surfactant formulation of 0.1% Tween 80 and 5% glycerol as a co surfactant, with a homogenization technique using a magnetic stirrer at a speed of 15,000 Rpm for 120 minutes. The results of the anticancer activity test showed that the IC50 value for T47D cells was 150.2 µg/mL. the nanoparticles formed were characterized using % transmittance value, and Particle Size Analyzer (PSA) and PDI to determine particle size. size. The best nanoparticle test results were obtained in the formula with a dose of 2000ug/mL which had physical quality properties with a particle size of 276.2 nm; The polydispersity index is 0.324 with nanoparticle size and has the most homogeneous particle distribution. The stability of the preparation using organoleptic, pH and viscosity tests gave quite stable results for 14 days so that it could be continued with stability tests to determine shelf life.

Isolation of active compounds from Streptomyces sennicomposti GMY01 and cytotoxic activity on breast cancer cells line

The occurrence of resistance to anticancer and the emergence of serious side effects due to chemotherapy is one of the main problems in cancer treatment, including breast cancer. The need for effective anticancer with a specific target is urgently required. Streptomyces are widely known as the potential producers of new anticancer molecules. Previously reported that the methanol extract of Streptomyces sennicomposti GMY01 isolated from Krakal Coast, Gunungkidul had very strong cytotoxic activity against MCF-7 and T47D breast cancer cells with IC50 values of 0.6 and 1.3 μg/mL, respectively. The following study aimed to isolate and identify active compounds of the S. sennicomposti GMY01 and evaluate its cytotoxic activity. The study was started by re-culturing and re-fermented optimization of S. sennicomposti GMY01 in a larger volume, then the bacteria were extracted using methanol following the bioassay-guided isolation of the extract obtained. The active compounds obtained were then structurally determined using UV/Vis spectroscopy, Fourier Transform-Infrared (FT-IR), Liquid Chromatography-Mass Spectroscopy (LC-MS), 1H NMR, and 13C NMR and analyzed for their cytotoxic activity using MTT assay on MCF-7 and normal Vero cells line. The results showed that the culture of the S. sennicomposti GMY01 using Starch Nitrate Broth (SNB) media yields the best results compared to other culture media. An active anticancer compound namely mannotriose was successfully isolated from the methanol extract with an IC50 value of 5.6 μg/mL and 687 μg/mL against the MCF-7 and Vero cells lines, respectively, indicating that this compound showed strong cytotoxic activity with high selectivity.

The Herbal Combination Shu Gan Jie Yu Regulates the SNCG/ER-a/AKT-ERK Pathway in DMBA-Induced Breast Cancer and Breast Cancer Cell Lines Based on RNA-Seq and IPA Analysis.

Soothing the liver (called Shu Gan Jie Yu in Chinese, SGJY) is a significant therapeutic method for breast cancer in TCM. In this study, 3 liver-soothing herbs, including Cyperus rotundus L., Citrus medica L. var. sarcodactylis Swingle and Rosa rugosa Thunb. were selected and combined to form a SGJY herbal combinatory. To investigate the inhibiting effect of SGJY on breast cancer in vivo and vitro, and to explore the potential mechanisms. SGJY herbal combination was extracted using water. A breast cancer rat model was developed by chemical DMBA by gavage, then treated with SGJY for 11 weeks. The tumor tissue was preserved for RNA sequencing and analyzed by IPA software. The inhibition effects of SGJY on MCF-7 and T47D breast cancer cells were investigated by SRB assay and cell apoptosis analysis, and the protein expression levels of SNCG, ER-α, p-AKT and p-ERK were measured by western blotting. SGJY significantly reduced the tumor weight and volume, and the level of estradiol in serum. The results of IPA analysis reveal SGJY upregulated 7 canonical pathways and downregulated 16 canonical pathways. Estrogen receptor signaling was the key canonical pathway with 9 genes downregulated. The results of upstream regulator analysis reveal beta-estradiol was the central target; the upstream regulator network scheme showed that 86 genes could affect the expression of the beta-estradiol, including SNCG, CCL21 and MB. Additionally, SGJY was verified to significantly alter the expression of SNCG mRNA, CCL21 mRNA and MB mRNA which was consistent with the data of RNA-Seq. The inhibition effects of SGJY exhibited a dose-dependent response. The apoptosis rates of MCF7 and T47D cells were upregulated. The protein expression of SNCG, ER-α, p-AKT and p-ERK were all significantly decreased by SGJY on MCF-7 and T47D cells. The results demonstrate that SGJY may inhibit the growth of breast cancer. The mechanism might involve downregulating the level of serum estradiol, and suppressing the protein expression in the SNCG/ER-α/AKT-ERK pathway.

Isolation and Cytotoxic Activity Test of Alkaloids from Dichloromethane Fraction of Bark of Tampa Badak (Voacanga foetida (Blume) Rolfe) Against T47D Cell Line

Cancer is a problem in the health sector because this disease has an increasing incidence of morbidity and mortality. While the treatment still leaves some drug side effects, which cause discomfort for cancers sufferers. The arises because most cancer drugs work non-selectively. Because of some of the problems above, it is necessary to encourage the search for alternative drugs treatment of cancer. Voacanga foetida (Blume) Rolfe (Apocynaceae) is a species of plant from the genus Voacanga known as the tampa badak from West Sumatra. This plant is known to be source of indole alkaloids and also bis-indole alkaloids potential as cancer drugs. Therefore, in this study we are interested to explore the potency of this plant as natural product sources with potential cytotoxic activity. The study was started from the isolation process and continued by characterization of the isolated compounds and then testing their cytotoxic activity T47D breast cancer cell line. The isolation process of alkaloid compounds were performed by acid-base extraction, liquid-liquid fractionation, and followed by separation using column chromatography. Then,the potency of cytotoxic activity of the isolates were screened through Brine Shrimp Lethality Test (BSLT) method and evaluated by MTT assay. The structure of three isolated alkaloids (VFB-DB1.1; VFB-DB2.1; and VFB-DB2.2) were charachterized using spectroscopic analyses, including UV and FT-IR. One isolated compound (VFB-DB1.1) was also characterized using 1H NMR spectroscopy. Based on the similarity of 1H NMR spectra of isolated compound when compared with the literature, compound VFB-DB1.1 was identified as voacangine. Then, the BSLT and MTT assay result showed that VFB-DB1.1 exhibited LC50 value of 15.8 µg/mL againt Artemia salina L.and IC50 value of 8.9 µg/mL against T47D breast cancer cells, respectively.

5-Oxo-ETE/OXER1: A Link between Tumor Cells and Macrophages Leading to Regulation of Migration.

Chronic inflammation is an important factor in the development of cancer. Macrophages found in tumors, known as tumor associated macrophages (TAMs), are key players in this process, promoting tumor growth through humoral and cellular mechanisms. 5-oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE), an arachidonic acid metabolite, has been described to possess a potent chemoattractant activity for human white blood cells (WBCs). The biological actions of 5-oxo-ETE are mediated through the GPCR 5-oxo-6E,8Z,11Z,14Z-eicosatetraenoic acid receptor (OXER1). In addition, we have previously reported OXER1 as one of the membrane androgen receptors with testosterone antagonizing 5-oxo-ETE's actions. OXER1 is highly expressed in inflammatory cells and many normal and cancer tissues and cells, including prostate and breast cancer, promoting cancer cell survival. In the present study we investigate the expression and role of OXER1 in WBCs, THP-1 monocytes, and THP-1 derived macrophages, as well as its possible role in the interaction between macrophages and cancer cells (DU-145 and T47D). We report that OXER1 is differentially expressed between WBCs and macrophages and that receptor expression is modified by LPS treatment. Our results show that testosterone and 5-oxo-ETE can act in an antagonistic way affecting Ca2+ movements, migration, and cytokines' expression in immune-related cells, in a differentiation-dependent manner. Finally, we report that 5-oxo-ETE, through OXER1, can attract macrophages to the tumor site while tumor cells' OXER1 activation in DU-145 prostate and T47D breast cancer cells, by macrophages, induces actin cytoskeletal changes and increases their migration.

Uji Aktivitas Sel Kanker Payudara T47D Ekstrak Etil Asetat Daun Glodokan Tiang (Polyalthia longifolia L.) Secara In Vitro

Cancer is one of the main causes of death throughout the world. Breast cancer is a non-communicable disease and a type of cancer that is often suffered by women. Breast cancer is a reproductive health problem, both in the world and in Indonesia, which is now a serious concern. Medical treatment of cancer is usually carried out with chemotherapy, surgery and radiotherapy, but the Indonesian people are familiar with and use efficacious plants as an effort to cure various diseases, including cancer. One of them is by using glodokan mast leaves or Polyalthia longifolia L. as natural chemotherapy from biological ingredients. This plant is reported to be high in antioxidant content, so it can be used as an anticancer agent, especially T47D breast cancer. The aim of this research is to examine the compound content and activity of T47D breast cancer cells from P. longifolia leaf extract. This research is basic experimental research, namely by comparing the IC50 value of ethyl acetate extract on young and old leaves. Based on the research results, it is known that the ethyl acetate extract in young and old leaves contains alkaloids, flavonoids, tannins and terpenoids which are useful as anticancer compounds. Cytotoxic activity of ethyl acetate extract of P. longifolia leaves against T47D breast cancer cells with an IC50 value of 253.76 μg/mL on old leaves and young leaves of 220.54 μg/mL with moderate cytotoxicity.

Cytotoxic activity of ethyl acetate extract of Chromolaena odorata on MCF7 and T47D breast cancer cells.

One of the most cancers in women that can be fatal is breast cancer. Radiation therapy, chemotherapy, or a combination of the two are often used to treat cancer, and these treatments tend to modify the immune system and weaken defences. Using natural compounds from plants has become a research interest to prevent cancer cell development. The aim of this study was to determine the anticancer activities of ethyl acetate extract of Chromolaena odorata (EACO) against breast cancer cells (MCF-7 and T47D). The viability of the cells was determined by the MTT colorimetry assays. The apoptosis test was performed by using flow cytometry. The IC50 value for MCF-7 cells was 218.78 µg/mL and 307.61 µg/mL for T47D. The extract acted selectively against breast cancer cells, with selectivity indexes against MCF-7 and T47D were 12.77 and 9.08, respectively. The viable cells of T47D cells were decreased from 85±36.5% (24 hours) to 54±34% (48 hours) after treatment with IC50 of EACO. Significant decrease of the MCF-7's viable cells were observed between 48 and 72 hours after treatment with IC50 (68.5±17.7% to 51.01±12.1%, respectively). Apoptosis assay showed that T47D and MCF-7 cells were mainly in the necrosis stage (83.35±0.49% and 95.15±1.76%, respectively). This study suggested that ethyl acetate extract of C. odorata is promising to be developed as an anticancer agent.

Pentagamavunone-1 inhibits aggressive breast cancer cell proliferation through mitotic catastrophe and ROS-mediated activities: in vitro and in vivo studies

Pentagamavunone-1 (PGV-1), an analog of curcumin, has been studied for its cytotoxic effects in 4T1, MCF7, MCF7/HER2, and T47D breast cancer cells. Its antiproliferative effect is partly mediated through G2/M arrest; however, its molecular mechanism during cell cycle progression remains unknown. In this study, we aimed to determine whether PGV-1 has any anticancer effects on highly aggressive breast cancer cells, with a focus on cell cycle regulatory activity, reactive oxygen species (ROS) generation, and their mediated effects on cancer cells. MDA-MB-231 (triple-negative) and HCC1954 (overexpressed HER2) immortalized human breast cancer cells were used in the study. PGV-1 exhibited cytotoxic activity with an irreversible antiproliferative impact on treated cells and had good selectivity when tested in fibroblast cells. Oral PGV-1 administration suppressed tumor growth in a cell-derived xenograft mouse model. PGV-1 induced the phosphorylation of Aurora A kinase and PLK1 in MDA-MB-231 cells, while PLK1 and cyclin B1 phosphorylation were enhanced in the PGV-1-treated HCC1954 cells during prometaphase arrest. Intracellular ROS production was substantially higher upon PGV-1 treatment following mitotic arrest, and this activity caused impairment of mitochondrial respiration, induced senescence, and subsequently triggered early-to-late apoptosis. Collectively, these results suggest that the molecular mechanism of PGV-1 involves the regulation of mitotic kinases to cause cell cycle arrest and the enhancement of ROS production to impair mitochondrial activity and induce cellular senescence. The therapeutic activities demonstrated by PGV-1 in this study show its potential as an appealing candidate for chemotherapy in breast cancer treatment.

Progestins and breast cancer hallmarks: The role of the ERK1/2 and JNK pathways in estrogen receptor positive breast cancer cells

Progestins used in hormonal contraceptives and menopausal hormone therapy (MHT) have been linked to increased breast cancer risk. Whether the association holds for all progestins is unclear and the underlying mechanisms remain poorly understood. We directly compared the effects of four progestins (medroxyprogesterone acetate (MPA), norethisterone acetate (NET-A), levonorgestrel (LNG) and drospirenone (DRSP)) to each other and the natural progestogen progesterone (P4) on selected cancer hallmarks. To provide mechanistic insight into these effects, we assessed the role of the progesterone receptor (PR), and the extracellular signal-related kinase (ERK1/2) and c-Jun N terminal (JNK) signaling pathways. We showed that the increased proliferation of the luminal T47D breast cancer cell line by P4 and all progestins, albeit to different extents, was inhibited by PR knockdown and inhibition of both the ERK1/2 and JNK pathways. While knockdown of the PR also blocked the upregulation of MKI67 and CCND1 mRNA expression by selected progestogens, only a role for the ERK1/2 pathway could be established in these effects. Similarly, only a role for the ERK1/2 pathway could be confirmed for progestogen-induced colony formation, whereas both the ERK1/2 and JNK pathways were required for cell migration in response to the three older progestins implicated in the etiology of breast cancer, MPA, NET-A and LNG. Together our results show that all the progestins elicit their effects on cell proliferation via a mechanism requiring the PR, ERK1/2 and JNK pathways. While the ERK1/2 and JNK pathways are also required for increased cell migration by the older progestins, only a role for the ERK1/2 pathway could be established in their effects on colony formation. Notably, the cytoplasmic PR was not needed for activation of the ERK1/2 pathway by the progestogens. Given that DRSP showed significantly lower proliferation than MPA and NET-A, and that it had no effect on breast cancer cell migration and colony formation, hormonal formulations containing the newer generation progestin DRSP may provide a better benefit/risk profile towards breast cancer than those containing the older generation progestins.

Abstract LB_A24: Baicalein suppresses tumorigenesis of the ER𝛼 positive of breast cancer cells by targeting multiple signaling pathways

Abstract The anti-tumor properties of baicalein, a flavonoid compound, have been extensively documented. However, the specific effects of baicalein on ER𝛼 positive breast cancer cell lines, namely T47-D and MCF-7, are less well-known. In this study, we conducted comprehensive in vitro experiments to elucidate the comparative impacts of baicalein on these two cell lines. Our results demonstrate that baicalein exerts robust anti-cancer effects, inducing morphological changes, reducing colony formation, and inhibiting cell proliferation in both T47-D and MCF-7 cells. These effects were more pronounced at higher concentrations. Additionally, baicalein treatment impeded the migratory capabilities of both cell lines, as shown by wound healing assays. Furthermore, our data show that baicalein triggers apoptosis, leading to an increase in early apoptotic, late apoptotic, and dead cells. This apoptotic process appears to be caspase 3/7-dependent. Interestingly, the pro-apoptotic effects were more potent in T47-D cells, accompanied by significant upregulation of pro-apoptotic genes and downregulation of anti-apoptotic markers. Baicalein treatment also induced oxidative stress and DNA damage, evidenced by an increase in reactive oxygen species (ROS) and phosphorylation of ATM and H2A.X. Importantly, baicalein inhibited the PI3K signaling pathway, a key mediator of cancer progression. Genome-wide transcriptomic analysis revealed significant changes in gene expression patterns, with baicalein treatment causing both upregulation and downregulation of several genes. Pathway analysis revealed that cell cycle and ferroptosis pathways were activated in both cell lines upon baicalein treatment. In conclusion, our findings highlight the potential of baicalein as a therapeutic agent against breast cancer, while also revealing nuanced differences in response between the T47-D and MCF-7 breast cancer cell lines. Citation Format: Besa Xhabija, Aidan J. McLaughlin, Ibiere Lovelyn Epelle, Tristan H. Nielson, Elisabeta Ujeniuc, Mariam I. Duhaini. Baicalein suppresses tumorigenesis of the ER𝛼 positive of breast cancer cells by targeting multiple signaling pathways [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr LB_A24.

RAD50 Deficient in a Breast Cancer Model Predicts Sensitivity to PARP Inhibitors.

Breast and ovarian tumors with pathogenic variants in BRCA1 or BRCA2 genes are more sensitive to poly (ADP-ribose) polymerase inhibitors (PARPi) treatment than wild-type tumors. Pathogenic variants in non-BRCA1/2 homologous recombination repair genes (HRR) also concede sensitivity to PARPi treatment. RAD50 participates in the Mre11-Rad50-Nbn (MRN) complex of the HRR pathway and plays an important role in DNA repair. The objective of this study is to evaluate whether RAD50 protein deficiency modulates the PARPi response in breast cancer cell lines. T47D breast cancer cell line was modified using small interfering RNA and CRISPR/Cas9 technology, to knockout the RAD50 gene. PARPi response (niraparib, olaparib and rucaparib alone or in combination with carboplatin), in T47D and T47D-edited clones, was evaluated by cell viability, cell cycle, apoptosis and protein expression analyses. Treatment with niraparib and carboplatin exerted a synergistic effect on T47D-RAD50 deficient cells and an antagonistic effect on T47D cells parental. Cell cycle analysis demonstrated an increase in the G2/M population in cells treated with niraparib or rucaparib alone or in combination with carboplatin. T47D-RAD50 deficient cells treated with rucaparib and carboplatin exhibited twofold levels in late apoptosis, also showing differences in PARP activation. All T47D RAD50 deficient clones treated with niraparib or rucaparib combined with carboplatin, or rucaparib alone showed increased levels of H2AX phosphorylation. T47D RAD50 deficient cells treated with PARP inhibitors alone or in combination with carboplatin showed cell cycle arrest in the G2/M phase, leading to death by apoptosis. Thus, RAD50 deficiency may be a good biomarker for predicting PARPi response.

Unravelling transcriptomic complexity in breast cancer through modulation of DARPP-32 expression and signalling pathways

DARPP-32 is a key regulator of protein-phosphatase-1 (PP-1) and protein kinase A (PKA), with its function dependent upon its phosphorylation state. We previously identified DKK1 and GRB7 as genes with linked expression using Artificial Neural Network (ANN) analysis; here, we determine protein expression in a large cohort of early-stage breast cancer patients. Low levels of DARPP-32 Threonine-34 phosphorylation and DKK1 expression were significantly associated with poor patient prognosis, while low levels of GRB7 expression were linked to better survival outcomes. To gain insight into mechanisms underlying these associations, we analysed the transcriptome of T47D breast cancer cells following DARPP-32 knockdown. We identified 202 differentially expressed transcripts and observed that some overlapped with genes implicated in the ANN analysis, including PTK7, TRAF5, and KLK6, amongst others. Furthermore, we found that treatment of DARPP-32 knockdown cells with 17β-estradiol or PKA inhibitor fragment (6–22) amide led to the differential expression of 193 and 181 transcripts respectively. These results underscore the importance of DARPP-32, a central molecular switch, and its downstream targets, DKK1 and GRB7 in breast cancer. The discovery of common genes identified by a combined patient/cell line transcriptomic approach provides insights into the molecular mechanisms underlying differential breast cancer prognosis and highlights potential targets for therapeutic intervention.

A molecular toolbox to study progesterone receptor signaling

Progesterone receptor (PR) signaling is required for mammary gland development and homeostasis. A major bottleneck in studying PR signaling is the lack of sensitive assays to measure and visualize PR pathway activity both quantitatively and spatially. Here, we develop new tools to study PR signaling in human breast epithelial cells. First, we generate optimized Progesterone Responsive Element (PRE)-luciferase constructs and demonstrate that these new reporters are a powerful tool to quantify PR signaling activity across a wide range of progesterone concentrations in two luminal breast cancer cell lines, MCF7 and T47D. We also describe a fluorescent lentiviral PRE-GFP reporter as a novel tool to visualize PR signaling at the single-cell level. Our reporter constructs are sensitive to physiological levels of progesterone. Second, we show that low background signaling, and high levels of PR expression are a prerequisite for robustly measuring PR signaling. Increasing PR expression by transient transfection, stable overexpression in MCF7 or clonal selection in T47D, drastically improves both the dynamic range of luciferase reporter assays, and the induction of endogenous PR target genes as measured by qRT-PCR. We find that the PR signaling response differs per cell line, target gene and hormone concentration used. Taken together, our tools allow a more rationally designed approach for measuring PR signaling in breast epithelial cells.

Anticancer effect of covalent purine-containing EGFR TKI, ZZC4 and its mechanism of action through network pharmacology

AimsEpidermal growth factor receptor (EGFR) has been documented in many malignancies as participating in the progression of cancer cells. Here, we present a novel EGFR tyrosine kinase inhibitor, ZZC4, and examine its effect on cancer cell proliferation, migration, and tumor-bearing xenograft models. Main methodsThe antiproliferative effect of ZZC4 was assessed in vitro by MTT assay, colony formation, and wound healing assay and in vivo with tumor-bearing xenograft nude mice. Further, Western blotting analysis and computational network pharmacology were used to explore and understand the mechanism of ZZC4. Key findingsThe results showed that ZZC4 potently inhibited the proliferation of lung, breast, and melanoma cells, and was more sensitive to lung cancer cells HCC827, H1975, and breast cancer cell T47D. In vitro findings were corroborated in vivo as results showed the suppressive effect of ZZC4 on HCC827 and H1975 tumor growth. Western blotting analysis confirmed that ZZC4 is an effective inhibitor of the EGFR pathways as it down-regulated p-EGFR, p-Akt, and p-MAPK. Computational molecular docking confirmed the strong binding affinity between ZZC4 and EGFR. Moreover, network pharmacology suggested that ZZC4 might play a suppressive role in the progression of malignancies with EGFR/PI-3K/Akt axis dysregulation or in cancer-related drug resistance. SignificanceOur study showed that ZZC4 is an anticancer drug candidate.

Effect of Black Rice Bran ‘Sembada Hitam’ on T47D Breast Cancer Cells

Indonesians have a rich tradition of incorporating black rice into their diet as a functional food due to its high antioxidant content. This research investigates the effects of the ethanolic extract of "Sembada Hitam" black rice bran on T47D breast cancer cells, specifically its cytotoxic, cell growth, and apoptotic induction properties. The MTT assay method was used to evaluate the cytotoxicity of the black rice bran extract on T47D cells after 24 and 48 hours of incubation. The acridine orange/propidium iodide (AO/PI) dye double staining method was employed to assess the apoptosis-inducing properties of the extract. Additionally, a cell growth assay was conducted to evaluate the effect of the extract on cell growth, with observations recorded on days 0, 3, and 6. The results revealed that the ethanolic extract of black rice bran "Sembada Hitam," when administered at various concentrations ranging from 7.81 to 1000 µg/mL, did not exhibit cytotoxic effects on T47D cells during the 24 and 48 hours of incubation. The cell growth assay revealed that T47D cells treated with the ethanolic extract of "Sembada Hitam" black rice bran at concentrations of 250 and 500 µg/mL exhibited lower growth rates than the 1% DMSO group from the 3rd to 6th day after incubation. The ethanolic extract of "Sembada Hitam" at concentrations of 250, 500, and 1000 µg/mL resulted in cell death of 10.64 ± 2.98%, 9.99 ± 5.87%, and 5.84 ± 0.78%, respectively. In conclusion, this study found that the ethanolic extract of "Sembada Hitam" black rice bran did not demonstrate significant cytotoxic effects on T47D breast cancer cells and is, therefore, unlikely to be a suitable candidate for an anti-cancer agent.

Investigating the Properties and Cytotoxicity of Cisplatin-Loaded Nano-Polybutylcyanoacrylate on Breast Cancer Cells

Background: This study aimed to develop a novel drug formulation using polybutylcyanoacrylate (PBCA) nanoparticles to deliver cisplatin, a commonly used chemotherapeutic agent for breast cancer treatment.Materials and Methods: PBCA nanoparticles were synthesized using a mini-emulsion polymerization method, and the resulting NPs were comprehensively characterized for their physical properties, such as size, size distribution, zeta potential, drug loading, and encapsulation efficiency. In addition, the cytotoxicity of the NPs was assessed, along with their ability to release the entrapped drugs over time. Results: The results showed that the PBCA nanoparticles had a mean size of 457 ± 7.4 nm, a size distribution of 0.253±0.011 and a negative zeta potential of -12.3 ± 1.3 mV. The drug encapsulation efficiency and loading capacity of cisplatin-PBCA were found to be 45.6 ± 2.7% and 3.5 ±0.8%, respectively; The release of the drug from the PBCA was estimated to be approximately 12.2±1.1% after 45 hours. The cytotoxic effects of the nanoparticle formulation were significantly enhanced compared to the free drug. The cytotoxicity of cisplatin-PBCA was evaluated in the T-47D breast cancer cell line, showing promising results as a potential drug formulation for breast cancer therapy. Conclusions: These findings suggest that cisplatin-PBCA may offer advantages over traditional cisplatin formulations, potentially improving the efficacy and reducing the toxicity of breast cancer treatment.