Potential Of Breast Cancer Cells Research Articles

A feasible strategy for fabricating pH-responsive SN-38 loaded europium metal-organic framework delivery for promising treatment for breast cancer

One of the significant challenges in cancer therapy is the development of biocompatible drug delivery systems (DDS) with enhanced penetration retention effect (EPR) and precision targeting. The current study aimed to establish a one-pot synthesis of 7-ethyl-10-hydroxy camptothecin (SN-38) loaded europium-metal-organic framework (SN-38@Eu-MOF) and evaluate its anticancer potential against breast cancer. High drug loading efficiency (85.3 ± 0.02% in 48h at pH 5.0) and pH-sensitive regulated release of drug SN-38 were two characteristics of the fabricated Eu-MOFs. According to material characterization, the material's surface formed a monodispersed homogeneous rod-shaped structure adorned with SN-38, with an average particle size of 72 ± 0.23nm. Results of anticancer assays demonstrated that when compared to SN-38 alone, SN-38@Eu-MOFs showed improved anticancer potential in breast cancer cells (MCF-7 and MDA-MB-231). According to the mechanism of anticancer potential, SN-38@Eu-MOFs increased reactive oxygen species (ROS) levels and caused mitochondrial malfunction and DNA damage, which resulted in apoptosis. The study's findings indicate that SN-38@Eu-MOFs is a potentially biocompatible nanomaterial for drug delivery systems for treating breast cancer and other pharmaceutical applications.

Arnicolide D Inhibits Oxidative Stress-induced Breast Cancer Cell Growth and Invasion through Apoptosis, Ferroptosis, and Parthanatos.

Breast cancer is the most common malignant tumor in women, and its pathogenesis is very complicated. More and more studies have found that Traditional Chinese Medicine plays an important role in tumor prevention. To investigate the mechanism of arnicolide D isolated from Centipeda minima in breast cancer. Cell Counting Kit-8 (CCK-8), western blot, RT-qPCR, ELISA, flow cytometry, and Transwell were used to detect the effect of arnicolide D on the biological function of breast cancer cells. Arnicolide D promoted reactive oxygen species (ROS) production and induced a decrease in mitochondrial membrane potential in breast cancer cells, thereby inhibiting cell viability and increasing lactate dehydrogenase (LDH) release. Arnicolide D activated the classical apoptosis pathway to induce cell apoptosis; it significantly promoted PARP-1 expression, enhanced the nuclear translocation of apoptosis-inducing factor (AIF), and reduced the expression of AIF in mitochondria, indicating that it can induce the occurrence of parthanatos in a ROS dependent manner. In addition, arnicolide D down-regulated glutathione peroxidase 4 (GPX4) expression and increased the accumulation of Fe2+ and malondialdehyde (MDA), thereby activating ferroptosis. Apoptosis inhibitor, ferroptosis inhibitor, PARP inhibitor, PARP-1 siRNA, AIF siRNA and GPX4 overexpression vector significantly attenuated the inhibitory effect of arnicolide D on cell viability and reduced LDH release, which indicates that arnicolide D inhibits breast cancer cell growth by inducing apoptosis, parthanatos and ferroptosis. Arnicolide D also reduced breast cancer cell invasion and inhibited the expression of matrix metallopeptidase (MMP)-2 and MMP-9. Arnicolide D can activate a variety of cell death modes by inducing oxidative stress, thereby inhibiting the growth and invasion of breast cancer cells, indicating that arnicolide D has a good anti-tumor effect.

Polyphyllin VII Promotes Apoptosis in Breast Cancer by Inhibiting MAPK/ERK Signaling Pathway through Downregulation of SOS1.

Polyphyllin VII is a biologically active herbal monomer extracted from the traditional Chinese herbal medicine Chonglou. Many studies have demonstrated the anticancer activity of polyphyllin VII against various types of cancers, such as colon, liver, and lung cancer, but its effect on breast cancer has not been elucidated. In this study, we demonstrate that polyphyllin VII inhibited proliferation, increased production of intracellular reactive oxygen species, and decreased mitochondrial membrane potential in breast cancer cells. Notably, polyphyllin VII also induced apoptosis via the mitochondrial pathway. Transcriptome sequencing was used to analyze the targets of PPVII in regulating breast cancer cells. Mechanistic studies showed that polyphyllin VII downregulated Son of Sevenless1 (SOS1) and inhibited the MAPK/ERK pathway. Furthermore, PPVII exerted strong antitumor effects in vivo in nude mice injected with breast cancer cells. Our results suggest that PPVII may promote apoptosis through regulating the SOS1/MAPK/ERK pathway, making it a possible candidate target for the treatment of breast cancer.

Abstract PO4-24-03: Adiponectin modulates cell polarity according to ERα expression in breast cancer cells

Abstract INTRODUCTION: Tumor microenvironment (TME) is a complex and heterogeneous network, consisting of stromal and immune cells, embedded with cytokines, growth factors, soluble receptors, and exosomes. Mutual and dynamic crosstalk among cancer, stromal and immune cells predispose cancer cells to metastasis. Particularly, the main component of breast TME is represented by adipocytes, which secretory activity is compromised in obesity. Indeed, hypertrophic, and hyperplastic adipocytes undergo to a modified cytokines secretory pattern, characterized by a reduced secretion of Adiponectin, now recognized as a crucial factor in the pathogenesis of breast cancer. LKB1 is one the most important effector of Adiponectin transduction pathways, and recently it has been demonstrated its role as ERα coactivator in promoting breast cancer cell growth. Moreover, LKB1 is a key regulator in controlling cell polarity along with E-cadherin and Cdc42. Cell polarity has been considered essential for mammary epithelial integrity, and disruption of individual polarity proteins is sufficient to induce tumor progression. The aim of the present study was to investigate the effects of adiponectin on the regulation and alteration of cell polarity, essential for breast cancer cell growth and invasiveness. METHODS: Immunofluorescence analyses were done to detect protein localization in breast cancer cells. Protein expression was performed by immunoblotting in the presence or absence of ERa and LKB1 siRNA. LKB1/Cdc42 and LKB1/E-cadherin interaction was detected by Proximity ligation and immunoprecipitation assay respectively. Wound healing assay was carried out to evaluate GM130 orientation. Growth and metastatic potential of breast cancer cells were assessed in vivo by orthotopic model and metastatic study respectively. RESULTS: In Adiponectin-treated MCF-7 cells LKB1 is mostly present in the nucleus, recruited as ERa-coactivator, while in BT20 cells LKB1 is localized with E-cadherin in the cytosolic compartment, suggesting its role in polarity. Our results showed that in MCF-7 cells Adiponectin increases Cdc42 level depending on LKB1 expression. Moreover, Cdc42 and LKB1 interact and colocalized in the nucleus of Adiponectin-treated MCF-7 cells. On the contrary, LKB1 and Cdc42 are located with E-cadherin in the cytosol of BT20 cells, addressing their cytosolic cooperation in maintaining cell polarity, as confirmed by an increased Cdc42 activity. Immunofluorescence analyses demonstrated a lack of Golgi realignment toward the front of the leading edge in MCF-7 cells treated with Adiponectin, not observed in BT20 cells. All this suggest a loss of cell polarity organization that predispose to cancer growth and progression, as confirmed by an increased tumor volume mass and a major number of lung metastatic events upon tail vein injection of adiponectin-treated ERα-positive cells with respect to untreated cells. CONCLUSION: In ERα-positive breast cancer cells Adiponectin modulates the expression of the main proteins involved in cell polarity, leading to increased growth, progression, and distant metastasis. Citation Format: Giuseppina Daniela Naimo, Martina Forestiero, Alessandro Paolì, Luca Gelsomino, Rocco Malivindi, Adele Elisabetta Leonetti, Francesca Giordano, Maria Luisa Panno, Loredana Mauro, Sebastiano Andò. Adiponectin modulates cell polarity according to ERα expression in breast cancer cells [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-24-03.

Abstract PO2-24-09: Prolonged Effects of Hypoxia in Luminal Breast Cancer Cells Promotes an Aggressive Phenotype

Abstract Aidan Moriarty Mentor: Dr. Min Yu Hypoxic Memory in Breast Cancer Cells Metastasis is the main cause of tumor-related mortality in breast cancer patients. Improving our understanding of the metastatic cascade is imperative to improve patient outcomes. Prior research indicates cancer cells with increased metastatic potential have acquired adaptive properties induced by factors in the tumor microenvironment (TME), including hypoxia. However, previous hypoxia research has been primarily focused on signaling changes that occur when cancer cells are in the hypoxic TME and does not account for long-term changes that may occur once cancer cells re-enter normoxia, such as when they metastasize. Our research in patient-derived circulating tumor cell (CTCs) lines and breast cancer cell lines has indicated that certain transcriptional changes are maintained after cells leave hypoxia, and that these post-hypoxic CTCs maintain a higher metastatic potential compared to cells not exposed to hypoxia. Taking an un-biased approach to define changes in hypoxia-exposed breast cancer cells upon reoxygenation, we performed bulk RNA-Seq on luminal breast cancer cell lines in various oxygen conditions over time. We found that a subset of genes that were differentially expressed in hypoxic conditions were maintained as up- or down-regulated after cells were reoxygenated, indicating a “hypoxic memory”. Additionally, a subset of genes were differentially expressed in the post-hypoxic cells compared to normoxia controls, demonstrating novel and prolonged gene expression changes induced by hypoxia exposure. We performed functional assays and observed that this post-hypoxic state is associated with a more aggressive phenotype in vitro. Current research in our lab is on-going to understand the epigenetic changes that may be responsible for this hypoxic memory to further understand the consequences of hypoxic memory in CTC biology and metastasis. Finally, we have designed a dual-reporter hypoxia-tracing system to validate our findings in vivo. This research will improve our understanding of the prolonged influence of hypoxia on metastatic potential in breast cancer cells and has the potential to inform future therapeutic strategies. Citation Format: Aidan Moriarty, Oihana Iriondo, Desirae Mecenas, Yilin Li, Yonatan Amzaleg, Remi Klotz, Min Yu. Prolonged Effects of Hypoxia in Luminal Breast Cancer Cells Promotes an Aggressive Phenotype [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-24-09.

Involvement of ferroptosis in eribulin-induced cytotoxicity in ovarian clear cell carcinoma

Ovarian clear cell carcinoma (OCCC) is a unique clinicopathological subtype of epithelial ovarian cancer that is resistant to standard chemotherapy. Eribulin, a microtubule dynamics inhibitor of halichondrin class, has unique effects in the cancer microenvironment such as induction of epithelization and reduction in metastatic potential in breast cancer cells; however, nothing is known about the effect of eribulin and the detailed mechanisms in OCCC. This study aimed to investigate the involvement of ferroptosis and its mechanism in the antitumor activity of eribulin in OCCC cells and a mouse xenograft model. We found that eribulin-induced cell death was reduced by ferroptosis inhibitors; deferoxamine, an iron chelator and ferrostatin-1, a lipid peroxidation inhibitor. Eribulin increased the levels of intracellular iron, reactive oxygen species (ROS), and lipid peroxides, and increased the mitochondrial membrane potential. Eribulin downregulated the expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), the mitochondrial enzyme dihydroorotate dehydrogenase (DHODH), and superoxide dismutase (SOD) activity. The combination of eribulin and ML210, a glutathione peroxidase 4-inhibiting ferroptosis inducer, had a synergistic effect on ferroptosis. Taken together, our findings show firstly that eribulin triggers ferroptosis in OCCC and this effect occurs via the suppression of the Nrf2–HO-1 signaling pathway, SOD activity and the promotion of lipid peroxidation. These findings suggest that eribulin-induced ferroptosis is associated with its anti-tumor effect and also could be a potential therapeutic target in OCCC.

Encapsulation and Delivery of Mitoxantrone Using Zirconium-Based Metal–Organic Frameworks (MOFs) and Their Cytotoxic Potential in Breast Cancer Cells

Mitoxantrone (MTX) is a drug employed in breast cancer treatment, but its application is largely limited due to side effects. A controlled delivery approach can potentially reduce the side effects. In this study, two zirconium (Zr)-based MOFs, UiO-66 and UiO-66-NH2, were studied for a more controlled delivery of MTX with a 40% and 21% loading capacity, respectively. Characterisation via powder X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectrometry, scanning electron microscopy, and dynamic light scattering confirmed the integrity of structure post-MTX loading. UV–vis spectrophotometry revealed distinctive release profiles, with UiO-66-MTX exhibiting a 25% cumulative release after 96 h in water and 120 h in PBS +10% FBS. UiO-66-NH2-MTX displayed a more sustained release, reaching 62% in water and 47% in PBS +10% FBS after 168 h. The interaction between MTX and the MOFs was also proposed based on computational modelling, suggesting a stronger interaction of UiO-66NH2 and MTX, and an optimised interaction of MTX in the tetrahedral and octahedral pores of the MOFs. The study also reports the release profile of the drug and antiproliferative activity against a panel of breast cancer cell lines (MDA-MB-231, MDA-MB-468, and MCF7) and a normal breast epithelial cell line (MCF10A). MTX-encapsulated MOFs were thoroughly characterised, and their biological activity was assessed in vitro. MTT cell viability assay indicated a higher IC50 value for MTX-loaded MOFs compared to free MTX in physiological conditions, albeit with a slower release profile. These findings suggest the potential of these MTX-loaded MOFs as an alternative avenue for formulation to mitigate side effects.

Abstract A037: Metabolic maneuvering of glycocalyx hypersialylation is a smart and healthy way of curbing metastatic potential in breast cancer

Abstract Metastatic breast cancer is currently the most deadly and incurable stage of breast cancer. A recent metabolic screen has identified sialic acid as a key player in progression of breast cancer metastasis. In the present study, we metabolically target the hypersialylation of metastatic breast cancer cells using appropriately designed nutritionary interventions. Our rationales are the following: (a) The aberrantly sialylated, hyperbranched glycocalyx promotes metastasis by facilitating cellular migration and immune evasion. (b) As hypersialylation relies heavily on enhanced sialic acid biosynthesis from the oncogenic glycolytic surge and preferential dietary uptake of glucose by cancer cells, it stands to reason that dietary changes can impact the extent of sialylation of the glycocalyx. Considering these points, we hypothesized that it was possible to control the degree of glycocalyx sialylation in breast cancer cells using an appropriate nutritionary regimen, which will in turn modulate the progression to invasive phenotype. The goal is to harness the metabolism of cancer cells themselves to curb their metastatic potential. Using a specific ketone-body forming metabolite called 3-hydroxybutyrate (HB) and lowering of glucose concentration, the cell culture medium was modified to mimic ketogenic diet. The response of metastatic breast cancer cells and normal breast epithelial cells was then monitored. The two main measures of cellular response were: cell surface sialylation via fluorescence microscopy and fluorescence lifetime imaging (FLIM) of intracellular NADH as a marker of metabolic index. We are currently investigating the consequences of nutritionary interventions on metastatic potential of breast cancer cells by measuring their impact on cellular proliferation, clonogenicity and migratory abilities. We have observed that the main metabolite of ketogenic diet, HB, tends to protect metastatic breast cancer cells from DOX treatment when supplemented in a low-glucose (LG) medium. However, the extent of increase in cell surface sialylation is very modest in comparison to that in normal breast epithelial cells. This differential increase in sialylation implies that a ketogenic diet might significantly promote the proliferation of healthy cells over the proliferation of metastatic breast cancer cells. FLIM measurements indicate that the chemotherapeutic, Doxorubicin tends to induce an initial preference for glycolysis in invasive breast cancer cells. While an HB rich LG media by itself promotes glycolysis in these cells, it suppresses any further Doxorubicin induced onset of glycolysis pointing to a protective mechanism against the chemotherapeutic. Through this ongoing study, we aim to decipher the right set of nutrients that would “deshield” the breast cancer cells and lower their metastatic disposition. The ultimate goal of our research is to determine a paradigm of drugs and diet that metastatic breast cancer cells are most responsive to, and that would translate into a viable remedy for metastatic breast cancer with minimal side-effects. Citation Format: Mohini Kamra, Yuan-I Chen, Paula C Delgado, Tim Yeh, Amy Brock, Sapun H Parekh. Metabolic maneuvering of glycocalyx hypersialylation is a smart and healthy way of curbing metastatic potential in breast cancer [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 A037.

A home-based lifestyle intervention program reduces the tumorigenic potential of triple-negative breast cancer cells

Translational research for the evaluation of physical activity habits and lifestyle modifications based on nutrition and exercise has recently gained attention. In this study, we evaluated the effects of serum samples obtained before and after a 12-week home-based lifestyle intervention based on nutrition and exercise in breast cancer survivors in terms of modulation of the tumorigenic potential of breast cancer cells. The home-based lifestyle intervention proposed in this work consisted of educational counselling on exercise and nutritional behaviors and in 12 weeks of structured home-based exercise. Triple-negative breast cancer cell line MDA-MB-231 was cultured in semi-solid medium (3D culture) with sera collected before (PRE) and after (POST) the lifestyle intervention program. Spheroid formation was evaluated by counting cell colonies after 3 weeks of incubation. Results show a slight but significant reduction of spheroid formation induced by serum collected POST in comparison to those obtained PRE. Moreover, statistical analyses aimed to find physiologic and metabolic parameters associated with 3D cell proliferation revealed the proliferative inducer IGF-1 as the only predictor of cell tumorigenic potential. These results highlight the importance of lifestyle changes for cancer progression control in a tertiary prevention context. Translational research could offer a useful tool to identify metabolic and physiological changes induced by exercise and nutritional behaviors associated with cancer progression and recurrence risk.

Exploration of SERPINA family functions and prognostic value in breast cancer based on transcriptome and in vitro analysis.

Breast cancer poses a significant risk to women worldwide, yet specific role of SERPINA gene family in breast cancer remains unclarified. Data were collected from online databases. SERPINA family gene expression was presented, and prognosis value was evaluated. Multi-omics methods were employed to explore the SERPINA-related biological processes, followed by comprehensive analyses of their roles in breast cancer. Single-cell data were analyzed to characterize the SERPINA family gene expression in different cell clusters. We selected SERPINA5 as the target gene. Via pan-cancer analysis, SERPINA5 was also investigated in various cancers. The experimental validation was conducted in MDA-MB-231 cell line eventually. SERPINA family showed differential expression in breast cancer, which were mainly expressed in myeloid cells, epithelial cells, and dendritic cells. SERPINA5 expression was upregulated in breast cancer, which was associated with a better prognosis. Immune infiltration illustrated the positive correlativity between SERPINA5 intensity and eosinophilic recruitment. Pan-cancer analysis indicated the function of SERPINA5 as a potential biomarker in other cancers. Finally, experimental validation demonstrated that SERPINA5 contributes to lower invasion and metastatic potential of breast cancer cells. With bioinformatics analysis, the significant role SERPINA family genes functioned in breast cancer was comprehensively explored, with SERPINA5 emerging as a key gene in suppressing breast cancer progression.

Novel STAT3 Inhibitor Exerts Anti-breast Cancer Effects Both In vitro and In vivo

Background: Breast cancer is one of the most common malignant tumors. Signal transduction and activators of transcription 3 (STAT3) have been demonstrated to play important roles in breast cancer. However, no direct inhibitor of STAT3 has been approved by the FDA for clinical use. Objective: LL1 is a newly designed STAT3 inhibitor that we identified. In this study, we investigated the cytotoxic effect of LL1 on breast cancer cells and its potential mechanisms. Methods: Colony formation and CCK-8 assay were used to detect the anti-proliferation of LL1. Flow cytometry was used to evaluate mitochondrial membrane potential and apoptosis in breast cancer cells following the treatment of LL1. The expression of proteins was analyzed using western blot, and the invasion and migration of cells were analyzed by wound healing assay and transwell assay. The xenograft model was used to evaluate the anti-cancer effect of LL1 in vivo. Results: LL1 selectively inhibited the expression of p-STAT3, but had no obvious effect on total STAT3. LL1 exhibited great potential in suppressing the proliferation of breast cancer in vitro. Moreover, LL1 induces apoptosis and the decrease of mitochondrial membrane potential in breast cancer cells. LL1 can also inhibit the invasion and migration of breast cancer cells. These cell biology changes may be induced via the regulation of Bcl-2, Bax, cleaved-caspase3, Survivn, Mmp-2, Mmp-9, N-cadherin, E-cadherin, vimentin, c-myc and cyclin D1 by LL1. In addition, LL1 exhibited great antitumor activity in vivo. Conclusion: Our study suggested that LL1 can be considered a promising candidate for the treatment of breast cancer.

Heat-shock protein 90α protects NME1 against degradation and suppresses metastasis of breast cancer.

NME1 has been exploited as a potential translational target for decades. Substantial efforts have been made to upregulate the expression of NME1 and restore its anti-metastasis function in metastatic cancer. Cycloheximide (CHX) chase assay was used to measure the steady-state protein stability of NME1 and HSP90α. The NME1-associating proteins were identified by immunoprecipitation combined with mass spectrometric analysis. Gene knockdown and overexpression were employed to examine the impact of HSP90AA1 on intracellular NME1 degradation. The motility and invasiveness of breast cancer cells were examined in vitro using wound healing and transwell invasion assays. The orthotopic spontaneous metastasis and intra-venous experimental metastasis assays were used to test the formation of metastasis in vivo, respectively. HSP90α interacts with NME1 and increases NME1 lifetime by impeding its ubiquitin-proteasome-mediated degradation. HSP90α overexpression significantly inhibits the metastatic potential of breast cancer cells in vitro and in vivo. A novel cell-permeable peptide, OPT22 successfully mimics the HSP90α function and prolongs the life span of endogenous NME1, resulting in reduced metastasis of breast cancer. These results not only reveal a new mechanism of NME1 degradation but also pave the way for the development of new and effective approaches to metastatic cancer therapy.

Targeted demethylation of the CDO1 promoter based on CRISPR system inhibits the malignant potential of breast cancer cells.

Cysteine dioxygenase 1 (CDO1) is frequently methylated, and its expression is decreased in many human cancers including breast cancer (BC). However, the functional and mechanistic aspects of CDO1 inactivation in BC are poorly understood, and the diagnostic significance of serum CDO1 methylation remains unclear. We performed bioinformatics analysis of publicly available databases and employed MassARRAY EpiTYPER methylation sequencing technology to identify differentially methylated sites in the CDO1 promoter of BC tissues compared to normal adjacent tissues (NATs). Subsequently, we developed a MethyLight assay using specific primers and probes for these CpG sites to detect the percentage of methylated reference (PMR) of the CDO1 promoter. Furthermore, both LentiCRISPR/dCas9-Tet1CD-based CDO1-targeted demethylation system and CDO1 overexpression strategy were utilized to detect the function and underlying mechanism of CDO1 in BC. Finally, the early diagnostic value of CDO1 as a methylation biomarker in BC serum was evaluated. CDO1 promoter was hypermethylated in BC tissues, which was related to poor prognosis (p<.05). The CRISPR/dCas9-based targeted demethylation system significantly reduced the PMR of CDO1 promotor and increased CDO1 expression in BC cells. Consequently, this leads to suppression of cell proliferation, migration and invasion. Additionally, we found that CDO1 exerted a tumour suppressor effect by inhibiting the cell cycle, promoting cell apoptosis and ferroptosis. Furthermore, we employed the MethyLight to detect CDO1 PMR in BC serum, and we discovered that serum CDO1 methylation was an effective non-invasive biomarker for early diagnosis of BC. CDO1 is hypermethylated and acts as a tumour suppressor gene in BC. Epigenetic editing of abnormal CDO1 methylation could have a crucial role in the clinical treatment and prognosis of BC. Additionally, serum CDO1 methylation holds promise as a valuable biomarker for the early diagnosis and management of BC.

MiR-203 drives breast cancer cell differentiation

A hallmark of many malignant tumors is dedifferentiated (immature) cells bearing slight or no resemblance to the normal cells from which the cancer originated. Tumor dedifferentiated cells exhibit a higher capacity to survive to chemo and radiotherapies and have the ability to incite tumor relapse. Inducing cancer cell differentiation would abolish their self-renewal and invasive capacity and could be combined with the current standard of care, especially in poorly differentiated and aggressive tumors (with worst prognosis). However, differentiation therapy is still in its early stages and the intrinsic complexity of solid tumor heterogeneity demands innovative approaches in order to be efficiently translated into the clinic. We demonstrate here that microRNA 203, a potent driver of differentiation in pluripotent stem cells (ESCs and iPSCs), promotes the differentiation of mammary gland tumor cells. Combining mouse in vivo approaches and both mouse and human-derived tridimensional organoid cultures, we report that miR-203 influences the self-renewal capacity, plasticity and differentiation potential of breast cancer cells and prevents tumor cell growth in vivo. Our work sheds light on differentiation-based antitumor therapies and offers miR-203 as a promising tool for directly confronting the tumor-maintaining and regeneration capability of cancer cells.

Functional inhibition of RECQL5 helicase elicits non-homologous end joining response and sensitivity of breast cancers to PARP inhibitor.

Poly (ADPRibose) Polymerase inhibitor (PARPi) are clinically approved for the treatment of BRCA-mutated hereditary breast and ovarian cancers with homologous recombination (HR) deficiency, based on synthetic lethality concept. However, ∼90% of breast cancers are BRCA-wild type; they repair PARPi mediated damage through HR, leading to intrinsic de novo resistance. Hence, there is an unmet need of exploring novel targets in HR-proficient aggressive breast cancers for PARPi treatment. RECQL5 physically interacts and disrupts RAD51 from pre-synaptic filaments, aiding HR resolution, replication fork protection and preventing illegitimate recombination. In the current investigation, we show that targeted inhibition of HR by stabilization of RAD51-RECQL5 complex by a pharmacological inhibitor of RECQL5 (4a; 1,3,4-oxadiazole derivative) in the presence of PARPi [talazoparib (BMN673)] leads to abolition of functional HR with uncontrolled activation of NHEJ repair. This was assessed by GFP based NHEJ reporter assay, KU80 recruitment and in vitro NHEJ based plasmid ligation assay. Concomitant treatment with talazoparib and 4a generates copious amounts of replication stress, prolonged cell cycle arrest, extensive double strand breaks (DSBs) and mitotic catastrophe, leading to sensitization of HR-proficient breast cancers. Suppression of NHEJ activity abolishes 4a-mediated sensitization of breast cancers to PARPi treatment. Imperatively, 4a was ineffective against normal mammary epithelial cells, which expresses low RECQL5 vis-à-vis breast cancer cells. Moreover, functional inhibition of RECQL5 suppresses metastatic potential of breast cancer cells in response to PARPi. Together, we identified RECQL5 as a novel pharmacological target for expanding PARPi based treatment horizon for HR-proficient cancers.

Knockdown of PTK7 Reduces the Oncogenic Potential of Breast Cancer Cells by Impeding Receptor Tyrosine Kinase Signaling.

Protein tyrosine kinase 7 (PTK7), a catalytically defective receptor tyrosine kinase (RTK), is often upregulated in various cancers. This study aimed to validate PTK7 as a target for breast cancer (BC) and investigate its oncogenic signaling mechanism. BC tissue analysis showed significantly elevated PTK7 mRNA levels, especially in refractory triple-negative breast cancer (TNBC) tissues, compared with normal controls. Similarly, BC cell lines exhibited increased PTK7 expression. Knockdown of PTK7 inhibited the proliferation of T-47D and MCF-7 hormone-receptor-positive BC cell-lines and of HCC1187, MDA-MB-231, MDA-MB-436, and MDA-MB-453 TNBC cells. PTK7 knockdown also inhibited the adhesion, migration, and invasion of MDA-MB-231, MDA-MB-436, and MDA-MB-453 cells, and reduced the phosphorylation levels of crucial oncogenic regulators including extracellular signal-regulated kinase (ERK), Akt, and focal adhesion kinase (FAK). Furthermore, PTK7 interacts with fibroblast growth factor receptor 1 (FGFR1) and epidermal growth factor receptor (EGFR) expressed in MDA-MB-231 cells. Knockdown of PTK7 decreased the growth-factor-induced phosphorylation of FGFR1 and EGFR in MDA-MB-231 cells, indicating its association with RTK activation. In conclusion, PTK7 plays a significant role in oncogenic signal transduction by enhancing FGFR1 and EGFR activation, influencing BC tumorigenesis and metastasis. Hence, PTK7 represents a potential candidate for targeted BC therapy, including TNBC.

Ruthenium complexes for breast cancer therapy

Abstract Breast cancer cells have long been inhibited by polypyridine Ru(II) complexes, which are excellent antitumor agents. Due to their multi-targeting properties, this class of ruthenium complexes has received increasing attention as anticancer drug candidates approach to various cellular targets. The aim of this review is to give information about the ligands that were carefully chosen for ruthenium complexes. There has been a great deal of interest in using ruthenium-based complexes to treat breast cancer. Several species have shown potential as treatment candidates. However, further research is needed to determine how these agents affect the metastatic potential of breast cancer cells. The mechanism of action of Ru-based anticancer candidates NAMI-A and KP1019 during phase I clinical trials has been discussed. This article explains hormone-positive breast cancer and triple-negative breast-cancer treatment by using Ru complexes. Although platinum (Pt-based) anticancer medication is widely used in cancer treatment, a minor improvement has been seen and that is Platinum replaced with Ruthenium for its anticancer properties. We have also highlighted the best effective ruthenium-based complexes in treating T.N.B.C. (triple-negative breast cancer) here in this collection.

Manipulating RKIP reverses the metastatic potential of breast cancer cells.

Breast cancer is a common tumor type among women, with a high fatality due to metastasis. Metastasis suppressors encode proteins that inhibit the metastatic cascade independent of the primary tumor growth. Raf kinase inhibitory protein (RKIP) is one of the promising metastasis suppressor candidates. RKIP is reduced or lost in aggressive variants of different types of cancer. A few pre-clinical or clinical studies have capitalized on this protein as a possible therapeutic target. In this article, we employed two breast cancer cells to highlight the role of RKIP as an antimetastatic gene. One is the low metastatic MCF-7 with high RKIP expression, and the other is MDA-MB-231 highly metastatic cell with low RKIP expression. We used high-throughput data to explore how RKIP is lost in human tissues and its effect on cell mobility. Based on our previous work recapitulating the links between RKIP and SNAI, we experimentally manipulated RKIP in the cell models through its novel upstream NME1 and investigated the subsequent genotypic and phenotypic changes. We also demonstrated that RKIP explained the uneven migration abilities of the two cell types. Furthermore, we identified the regulatory circuit that might carry the effect of an existing drug, Epirubicin, on activating gene transcription. In conclusion, we propose and test a potential strategy to reverse the metastatic capability of breast cancer cells by chemically manipulating RKIP expression.

Metformin ameliorates BMP2 induced adipocyte-like property in breast cancer cells

Neighboring adipocytes of tumor cells/cancer associated adipocytes supply many factors and fatty acids as fuel to cancer cells for inducing cancer progression and development. Epithelial breast cancer cells also differentiate into several cell types to meet various demands. This study reports that breast cancer cells exhibit inherent adipocyte-like property which is further enhanced in presence of BMP2. Antidiabetic metformin inhibits BMP2 induced adipocyte-like potential in breast cancer cells. Interestingly, breast cancer cells not only show lipid accumulation but also have ability to release lipid content. Thus, this study centers around the presence of the adipocyte cell-like property in breast cancer cells, the significance of BMP2 and metformin that may be explored in designing therapeutics against breast cancer.

Pharmacological anti-tumor effects of natural Chamaecyparis obtusa (siebold & zucc.) endl. Leaf extracts on breast cancer

Ethnopharmacological relevanceChamaecyparis obtusa (C. obtusa, cypress species) is a plant that grows mainly in the temperate Northern Hemisphere and has long been used as a traditional anti-inflammatory treatment in East Asia. C. obtusa contains phytoncides, flavonoids, and terpenes, which have excellent anti-cancer effects and have been reported to prevent the progression of various cancers. However, the detailed mechanisms underlying the anti-cancer effects of C. obtusa extracts are unknown. Aim of the studyWe sought to confirm the anti-cancer effects of C. obtusa leaf extracts and to reveal the mechanism of action, with the possibility of its application in the treatment or prevention of cancer. Material &methodsThe cytotoxicity of C. obtusa leaf extracts was confirmed using an MTT assay. Intracellular changes in protein levels were measured by immunoblotting, and mRNA levels were measured with qRT-PCR. Wound healing assay and transwell migration assay were used to evaluate the metastatic potential of breast cancer cells. The extract-induced apoptosis was observed using IncuCyte Annexin V Red staining analysis. A syngeneic breast cancer mouse model was established by injecting 4T1-Luc mouse breast cancer cells into the fat pad of female BALB/c mice, and the extract was administered orally. Luciferin solution was injected intraperitoneally to assess primary tumor development and metastasis by bioluminescence. ResultsC. obtusa leaf extracts were extracted with boiling water, 70% EtOH, and 99% EtOH. Among the extracts, the 99% EtOH extract of C. obtusa leaf (CO99EL) most clearly inhibited the tyrosine phosphorylation of Signal Transducer and Activator of Transcription 3 (pY-STAT3) in MDA-MB-231 breast cancer cells at a concentration of 25 and 50 μg/mL. In addition, CO99EL strongly inhibited not only endogenous pY-STAT3 levels but also IL-6-induced STAT3 activation in various types of cancer cells, including breast cancer. CO99EL inhibited metastatic potential by downregulating the expression of N-cadherin, fibronectin, TWIST, MMP2, and MMP9 in MDA-MB-231 breast cancer cells. CO99EL also induced apoptotic cell death by increasing cleaved caspase-3 and decreasing anti-apoptotic proteins Bcl-2 and Bcl-xL. In an in vivo syngeneic breast cancer mouse model, 100 mg/kg CO99EL suppressed tumor growth and induced apoptosis of cancer cells. Moreover, CO99EL significantly inhibited lung metastasis from primary breast cancer. ConclusionsOur study demonstrated that 100 mg/kg CO99EL has potent anti-tumor effects against breast cancer, thus suggesting that 100 mg/kg CO99EL has potential applications in the treatment and prevention of breast cancer.