Epithelial Breast Cancer Cells Research Articles

Abstract A085: Stromal PDGFRβ hyperactivation modulates the myeloid lineage in the brain metastatic microenvironment

Abstract Breast cancer is the most common cancer diagnosis worldwide, and an unfortunately high number of women die every year due to a lack of effective therapeutic strategies for metastatic breast cancer. Patients with brain metastases in particular have a significantly poorer prognosis than women with metastasis to other sites (e.g., lung, liver, bone). Previous studies by our group identified a ligand-receptor complex in the tumor microenvironment (TME) that promotes metastasis of breast cancer to the brain. This interaction between platelet-derived growth factor-BB (PDGFB), produced by cancerous breast epithelial cells, and its receptor, platelet-derived growth factor receptor beta (PDGFRβ), expressed by mesenchymal cells, is also prognostic of breast cancer metastasis to the brain in patients. The mechanism of how the PDGFB-PDGFRβ pathway mediates brain metastasis is still unclear and is the focus of our current work. To further analyze the biological effects of PDGFB, our group evaluated gene expression changes between primary human breast tumors expressing high PDGFB versus those expressing low PDGFB and found significantly more immune signaling in the low-expressing tumors. These results led us to hypothesize that the PDGFB-PDGFRβ pathway creates an immunosuppressive microenvironment, allowing for increased metastasis of cancerous cells. To test this, flow cytometry was completed on the brains, spleens, lungs, and livers of control mice and mutant mice expressing stromal-specific hyperactive PDGFRβ following intracardiac injection of PDGFB-expressing mammary tumor cells. No significant changes in immune cell populations were observed in non-tumor-bearing mice. However, in the brains of tumor-bearing mutant mice, there are significant changes to the myeloid lineage. Specifically, analysis at day 10 post-injection (prior to detectable metastatic lesions) revealed diminished CD45+CD11b+ populations. Segregating by CD45hi/CD45lo confirmed a profound decrease in CD45loCD11b+F4/80+ microglia, likely a tumor-suppressive population. Looking at day 16 post-injection (detectable metastatic lesions), there is a shift towards an increase in CD45+ CD11b+GR1+ infiltrating myeloid-derived suppressor cells (MDSCs) in experimental mice, likely a tumor-promoting population. Minimal changes were observed in the lungs and livers at any time point. Confirmatory immunofluorescence staining showed a decrease in tumor-infiltrating microglia (Iba1+) and a significant increase in tumor-infiltrating peripheral macrophages (F4/80+), mirroring the flow data. This experiment was then repeated to test the contribution of the ligand (PDGFB), where a significant increase of infiltrating microglia (Iba1+) was observed upon tumor cell knockdown of PDGFB. Together, these results suggest that the PDGFB-PDGFRβ pathway creates an immunosuppressive environment in the brain TME at least in part through reorchestration of the myeloid populations. Citation Format: Alexis A Mossing, Johnathon G Schiebel, Rebecca L Packard, Amrendra Kumar, Sarah A Steck, Nathaniel S Grabinski, Katie A Thies, Bri Wasik, Tasneem Ariswala, Gary Tozbikian, Johnathan Godbout, Steven T Sizemore, Paul R Lockman, Anna E Vilgelm, Gina M Sizemore. Stromal PDGFRβ hyperactivation modulates the myeloid lineage in the brain metastatic microenvironment [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 A085.

Abstract A089: Role of Vardhamana Pippali Rasayana (VPR) in human breast cancer cells

Abstract Serious concerns include delayed diagnosis and adverse side-effects of conventional treatment leading to residual morbidity in Breast cancer (BC) globally. Traditional Indian medicines/herbs via combination of conventional cancer are gaining increasing acceptance worldwide, playing a pivotal role as proven by their efficacy evaluation studies. Many plants are known to reduce the cell proliferation and tumor development after their treatment. Vardhamana Pippali Rasayana (VPR), an Ayurvedic herbal preparation of pippali (Piper longum) in gradually increasing and tapering dose is used to treat many cancers without any adverse side-effects. However, its anti-cancer role in breast cancer is not known yet. The present study has explored the cytotoxic and apoptotic effects of VPR in triplicates on human breast cancer (MCF7) and normal breast epithelial (MCF10A) cell lines at different concentrations after extracting piperine in aqueous and hydro-alcoholic soxhlet extract (0.25 to 50 μg/μl). The cytotoxic activity was carried out by MTT assay and results showed that a low IC50 was observed at 3.75 μg/μl of VPR against MCF-7 as compared with normal breast epithelial cells. Detection of apoptotic cells using suitable Annexin V was done and there was a time-dependent increase in percentage of annexin V positive cells upon treatment. The above results indicate that VPR may have a strong anti-cancerous potential. But other functional assays are warranted to validate the efficacy of the drug against breast cancer which are under progress in our laboratory. Citation Format: Dr.Richa Tripathi, Shivam Singh, Subhash Gupta, VG Huddar, Tanuja M Nesari, Ashok Sharma. Role of Vardhamana Pippali Rasayana (VPR) in human breast cancer cells [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 A089.

Phytochemicals from Pterocarpus angolensis DC and Their Cytotoxic Activities against Breast Cancer Cells.

Pterocarpus anglonesis DC is an indigenous medicinal plant belonging to the Pterocarpus genus of the Fabaceae family. It is used to treat stomach problems, headaches, mouth ulcers, malaria, blackwater fever, gonorrhea, ringworm, diarrhea, heavy menstruation, and breast milk stimulation. Column chromatography of the stem bark extracts resulted in the isolation of eight compounds, which included friedelan-3-one (1), 3α-hydroxyfriedel-2-one (2), 3-hydroxyfriedel-3-en-2-one (3), lup-20(29)-en-3-ol (4), Stigmasta-5-22-dien-3-ol (5), 4-O-methylangolensis (6), (3β)-3-acetoxyolean-12-en-28-oic acid (7), and tetradecyl (E)-ferulate (8). The structures were established based on NMR, IR, and MS spectroscopic analyses. Triple-negative breast cancer (HCC70), hormone receptor-positive breast cancer (MCF-7), and non-cancerous mammary epithelial cell lines (MCF-12A) were used to test the compounds' cytotoxicity. Overall, the compounds showed either no toxicity or very low toxicity to all three cell lines tested, except for the moderate toxicity displayed by lupeol (4) towards the non-cancerous MCF-12A cells, with an IC50 value of 36.60 μM. Compound (3β)-3-acetoxyolean-12-en-28-oic acid (7) was more toxic towards hormone-responsive (MCF-7) breast cancer cells than either triple-negative breast cancer (HCC70) or non-cancerous breast epithelial (MCF-12A) cells (IC50 values of 83.06 vs. 146.80 and 143.00 μM, respectively).

Assessments of anti-breast cancer activity and profiling of active compounds using LC-MS/MS from the Indonesian Agelas nakamurai

Breast cancer is now one of the leading causes of death in women worldwide. Finding a cure is, therefore, critical for women’s health. Marine sponge-derived drugs have gained interest in breast cancer treatment. The development of marine natural products into cancer therapy includes several stages. It starts with the screening using the cytotoxic test method, a preclinical trial using the animal mode, and clinical trial phases I and II. In this study, we focus on the basic cytotoxic test to find the new source of anti-breast cancer compounds derived from Agelas nakamurai to know the potential for further investigation to become lead compounds. However, the anti-breast cancer potential of the Indonesian marine sponge A. nakamurai has never been studied. This study aimed to evaluate the anti-breast cancer potential of extract and fraction of A. nakamurai against epithelial human breast cancer cells (MDA-MB-231 and MCF-7 cells line) and to preliminary profile the known active compounds. The maceration using methanol was used for extraction and followed by partitioning with varied solvents [ethyl acetate (EtOAc), butanol, and water]. Fractionation was done using normal phase open column chromatography, and liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) was used for analyzing compounds. MDA-MB-231, MCF-7, and HEK-293 cell lines were used for biological activities. The chromatographic separation of the EtOAc fraction led to the F7 subfraction which strongly inhibits proliferation against the MDA-MD-231 (IC50: 10.677 μg/mL), MCF-7 (IC50: 15.154 μg/mL), and HEK-293 cells line. The LC-MS/MS data of active fraction F7 contained gelatin-D and ageloxime-D. This study reported that fraction 7 of A. nakamurai showed strong activity against MDA-MB-231, MCF-7, and HEK-293 cell lines. Further analysis will be carried out to know the mechanisms of action of active compounds.

Metabolomic profiling of Medicago sativa-derived fungal endophytes and evaluation of their biological activities.

This study aimed to discover the potential of Medicago sativa-derived fungal endophytes as a prospective source of bioactive metabolites. In the present study, three different strains of fungal endophyte Aspergillus terreus were isolated from leaves L, roots T and stems St of Medicago sativa to explore their biological and chemical diversity. These isolated fungi were exposed to different fermentation conditions by adding various chemical elicitors to their solid fermentation media. According to LC-HRESIMS-based metabolomics and multivariate analysis, each chemical treatment had a different effect on the chemical profiles of the fungi. Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA) proposed several compounds with anticancer action against MCF-7 (a human breast cancer cell line) and MDA-MB-231 (a human epithelial breast cancer cell line).

Interfacial Organization and Forces Arising from Epithelial-Cancerous Monolayer Interactions.

The interfacial interactions between epithelia and cancer cells have profound relevance for tumor development and metastasis. Through monolayer confrontation of MCF10A (nontumorigenic human breast epithelial cells) and MDA-MB-231 (human epithelial breast cancer cells) cells, we investigate the epithelial-cancerous interfacial interactions at the tissue level. We show that the monolayer interaction leads to competitive interfacial morphodynamics and drives an intricate spatial organization of MCF10A cells into multicellular finger-like structures, which further branch into multiple subfinger-like structures. These hierarchical interfacial structures penetrate the cancer monolayer and can spontaneously segregate or even envelop cancer cell clusters, consistent with our theoretical prediction. By tracking the substrate displacements via embedded fluorescent nanobeads and implementing nanomechanical modeling that combines atomic force microscopy and finite element simulations, we computed mechanical force patterns, including traction forces and monolayer stresses, caused by the monolayer interaction. It is found that the heterogeneous mechanical forces accumulated in the monolayers are able to squeeze cancer cells, leading to three-dimensional interfacial bulges or cell extrusion, initiating the p53 apoptosis signaling pathways of cancer cells. We reveal that intercellular E-cadherin and P-cadherin of epithelial cells differentially regulate the interfacial organization including migration speed, directionality, spatial correlation, F-actin alignment, and subcellular protrusions of MCF10A cells; whereas E-cadherin governs interfacial geometry that is relevant to force localization and cancer cell extrusion, P-cadherin maintains interfacial integrity that enables long-range force transmission. Our findings suggest that the collaborative molecular and mechanical behaviors are crucial for preventing epithelial tissues from undergoing tumor invasion.

Altered Phenotypes of Breast Epithelial × Breast Cancer Hybrids after ZEB1 Knock-Out.

ZEB1 plays a pivotal role in epithelial-to-mesenchymal transition (EMT), (cancer) cell stemness and cancer therapy resistance. The M13HS tumor hybrids, which were derived from spontaneous fusion events between the M13SV1-EGFP-Neo breast epithelial cells and HS578T-Hyg breast cancer cells, express ZEB1 and exhibit prospective cancer stem cell properties. To explore a possible correlation between the ZEB1 and stemness/ EMT-related properties in M13HS tumor hybrids, ZEB1 was knocked-out by CRISPR/Cas9. Colony formation, mammosphere formation, cell migration, invasion assays, flow cytometry and Western blot analyses were performed for the characterization of ZEB1 knock-out cells. The ZEB1 knock-out in M13HS tumor cells was not correlated with the down-regulation of the EMT-related markers N-CADHERIN (CDH2) and VIMENTIN and up-regulation of miR-200c-3p. Nonetheless, both the colony formation and mammosphere formation capacities of the M13HS ZEB1 knock-out cells were markedly reduced. Interestingly, the M13HS-2 ZEB1-KO cells harbored a markedly higher fraction of ALDH1-positive cells. The Transwell/ Boyden chamber migration assay data indicated a reduced migratory activity of the M13HS ZEB1-knock-out tumor hybrids, whereas in scratch/ wound-healing assays only the M13SH-8 ZEB1-knock-out cells possessed a reduced locomotory activity. Similarly, only the M13HS-8 ZEB1-knock-out tumor hybrids showed a reduced invasion capacity. Although the ZEB1 knock-out resulted in only moderate phenotypic changes, our data support the role of ZEB1 in EMT and stemness.

Global transcriptomic analysis of breast cancer and normal mammary epithelial cells infected with Borrelia burgdorferi.

The bacterial spirochete Borrelia burgdorferi, the causative agent of Lyme Disease, can disseminate and colonize various tissues and organs, orchestrating severe clinical symptoms including arthritis, carditis, and neuroborreliosis. Previous research has demonstrated that breast cancer tissues could provide an ideal habitat for diverse populations of bacteria, including B. burgdorferi, which is associated with a poor prognosis. Recently, we demonstrated that infection with B. burgdorferi enhances the invasion and migration of triple-negative MDA-MB-231 cells which represent a type of breast tumor with more aggressive cancer traits. In this study, we hypothesized that infection by B. burgdorferi affects the expression of cancer-associated genes to effectuate breast cancer phenotypes. We applied the high-throughput technique of RNA-sequencing on B. burgdorferi-infected MDA-MB-231 breast cancer and normal-like MCF10A cells to determine the most differentially expressed genes (DEG) upon infection. Overall, 142 DEGs were identified between uninfected and infected samples in MDA-MB-231 while 95 DEGs were found in MCF10A cells. A major trend of the upregulation of C-X-C and C-C motif chemokine family members as well as genes and pathways was associated with infection, inflammation, and cancer. These genes could serve as potential biomarkers for pathogen-related tumorigenesis and cancer progression which could lead to new therapeutic opportunities.

An Increase in HSF1 Expression Directs Human Mammary Epithelial Cells toward a Mesenchymal Phenotype.

HSF1 is a well-known heat shock protein expression regulator in response to stress. It also regulates processes important for growth, development or tumorigenesis. We studied the HSF1 influence on the phenotype of non-tumorigenic human mammary epithelial (MCF10A and MCF12A) and several triple-negative breast cancer cell lines. MCF10A and MCF12A differ in terms of HSF1 levels, morphology, growth in Matrigel, expression of epithelial (CDH1) and mesenchymal (VIM) markers (MCF10A are epithelial cells; MCF12A resemble mesenchymal cells). HSF1 down-regulation led to a reduced proliferation rate and spheroid formation in Matrigel by MCF10A cells. However, it did not affect MCF12A proliferation but led to CDH1 up-regulation and the formation of better organized spheroids. HSF1 overexpression in MCF10A resulted in reduced CDH1 and increased VIM expression and the acquisition of elongated fibroblast-like morphology. The above-mentioned results suggest that elevated levels of HSF1 may direct mammary epithelial cells toward a mesenchymal phenotype, while a lowering of HSF1 could reverse the mesenchymal phenotype to an epithelial one. Therefore, HSF1 may be involved in the remodeling of mammary gland architecture over the female lifetime. Moreover, HSF1 levels positively correlated with the invasive phenotype of triple-negative breast cancer cells, and their growth was inhibited by the HSF1 inhibitor DTHIB.

Single-Cell Analysis Reveals Adipose Cancer-Associated Fibroblasts Linked to Trastuzumab Resistance in Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer

Trastuzumab, a first-line targeted agent for HER-2-positive breast cancer, often faces challenges due to resistance. The IGF-1R/IRS-1/AKT pathway hyperactivation has been linked to this resistance, but the primary culprit, whether epithelial cells or cancer-associated fibroblasts (CAFs), remains uncertain. To investigate, we employed seRNA-seq to differentiate CAFs and epithelial cells in trastuzumab-sensitive and resistant breast cancer samples. iTALK analysis revealed potential interactions between CAFs and epithelial cells through IGF-1. We then analyzed 43 HER-2-positive breast cancer samples treated with trastuzumab, confirming higher expression of IGF-1R/IRS-1/AKT pathway proteins using immunohistochemistry. Notably, we identified five CAFs subtypes with varying proportions in both trastuzumab-sensitive and resistant samples. Further analysis revealed elevated IGF-1 levels in CAFs of trastuzumab-resistant tissues, particularly in adipose CAFs. Immunohistochemistry staining corroborated overexpression of COL11A1 (an adipose CAF marker) and increased IGF-1R and Tyr-phosphorylated IRS-1 in HER-2-positive breast cancer, associated with poor trastuzumab response. Our findings suggest that CAFs, particularly adipose CAFs, may induce trastuzumab resistance in HER2-positive breast cancer epithelial cells through IGF-1-mediated activation of the IGF-1R/IRS-1/AKT pathway.

Differential response of MDA‑MB‑231 breast cancer and MCF10A normal breast cells to cytoskeletal disruption.

Metastasis remains a major clinical problem in cancer diagnosis and treatment. Metastasis is the leading cause of cancer‑related mortality but is still poorly understood. Cytoskeletal proteins are considered potential therapeutic targets for metastatic cancer cells because the cytoskeleton serves a key role in the migration and invasion of these cells. Vimentin and F‑actin exhibit several functional similarities and undergo quantitative and structural changes during carcinogenesis. The present study investigated the effects of vimentin and F‑actin deficiency on the survival and motility of breast cancer cells. In metastatic breast cancer cells (MDA‑MB‑231) and breast epithelial cells (MCF10A), vimentin was knocked down by small interfering RNA and F‑actin was depolymerized by latrunculin A, respectively. The effect of reduced vimentin and F‑actin content on cell viability was analyzed using the MTT assay and the proliferative capacity was compared by analyzing the recovery rate. The effect on motility was analyzed based on two processes: The distance traveled by tracking the cell nucleus and the movement of the protrusions. The effects on cell elasticity were measured using atomic force microscopy. Separately reducing vimentin or F‑actin did not effectively inhibit the growth and motility of MDA‑MB‑231 cells; however, when both vimentin and F‑actin were simultaneously deficient, MDA‑MB‑231 cells growth and migration were severely impaired. Vimentin deficiency in MDA‑MB‑231 cells was compensated by an increase in F‑actin polymerization, but no complementary action of vimentin on the decrease in F‑actin was observed. In MCF10A cells, no complementary interaction was observed for both vimentin and F‑actin.

Effective targeting of breast cancer by the inhibition of P-glycoprotein mediated removal of toxic lipid peroxidation byproducts from drug tolerant persister cells

Therapy resistance has long been considered to occur through the selection of pre-existing clones equipped to survive and quickly regrow, or through the acquisition of mutations during chemotherapy. Here we show that following in vitro treatment by chemotherapy, epithelial breast cancer cells adopt a transient drug tolerant phenotype characterized by cell cycle arrest, epithelial-to-mesenchymal transition (EMT) and the reversible upregulation of the multidrug resistance (MDR) efflux transporter P-glycoprotein (P-gp). The drug tolerant persister (DTP) state is reversible, as cells eventually resume proliferation, giving rise to a cell population resembling the initial, drug-naïve cell lines. However, recovery after doxorubicin treatment is almost completely eliminated when DTP cells are cultured in the presence of the P-gp inhibitor Tariquidar. Mechanistically, P-gp contributes to the survival of DTP cells by removing reactive oxygen species-induced lipid peroxidation products resulting from doxorubicin exposure. In vivo, prolonged administration of Tariquidar during doxorubicin treatment holidays resulted in a significant increase of the overall survival of Brca1−/−;p53−/− mammary tumor bearing mice. These results indicate that prolonged administration of a P-gp inhibitor during drug holidays would likely benefit patients without the risk of aggravated side effects related to the concomitantly administered toxic chemotherapy. Effective targeting of DTPs through the inhibition of P-glycoprotein may result in a paradigm shift, changing the focus from countering drug resistance mechanisms to preventing or delaying therapy resistance.

EMT induces characteristic changes of Rho GTPases and downstream effectors with a mitosis-specific twist

Epithelial-mesenchymal transition (EMT) is a key cellular transformation for many physiological and pathological processes ranging from cancer over wound healing to embryogenesis. Changes in cell migration, cell morphology and cellular contractility were identified as hallmarks of EMT. These cellular properties are known to be tightly regulated by the actin cytoskeleton. EMT-induced changes of actin-cytoskeletal regulation were demonstrated by previous reports of changes of actin cortex mechanics in conjunction with modifications of cortex-associated f-actin and myosin. However, at the current state, the changes of upstream actomyosin signaling that lead to corresponding mechanical and compositional changes of the cortex are not well understood. In this work, we show in breast epithelial cancer cells MCF-7 that EMT results in characteristic changes of the cortical association of Rho-GTPases Rac1, RhoA and RhoC and downstream actin regulators cofilin, mDia1 and Arp2/3. In the light of our findings, we propose that EMT-induced changes in cortical mechanics rely on two hitherto unappreciated signaling paths—i) an interaction between Rac1 and RhoC and ii) an inhibitory effect of Arp2/3 activity on cortical association of myosin II.

The Role and Therapeutic Targeting of CCR5 in Breast Cancer.

The G-protein-coupled receptor C-C chemokine receptor 5 (CCR5) functions as a co-receptor for the entry of HIV into immune cells. CCR5 binds promiscuously to a diverse array of ligands initiating cell signaling that includes guided migration. Although well known to be expressed on immune cells, recent studies have shown the induction of CCR5 on the surface of breast cancer epithelial cells. The function of CCR5 on breast cancer epithelial cells includes the induction of aberrant cell survival signaling and tropism towards chemo attractants. As CCR5 is not expressed on normal epithelium, the receptor provides a potential useful target for therapy. Inhibitors of CCR5 (CCR5i), either small molecules (maraviroc, vicriviroc) or humanized monoclonal antibodies (leronlimab) have shown anti-tumor and anti-metastatic properties in preclinical studies. In early clinical studies, reviewed herein, CCR5i have shown promising results and evidence for effects on both the tumor and the anti-tumor immune response. Current clinical studies have therefore included combination therapy approaches with checkpoint inhibitors.

A combination of a cell penetrating peptide and a protein translation inhibitor kills metastatic breast cancer cells

Cell Penetrating Peptides (CPPs) are promising anticancer and antimicrobial drugs. We recently reported that a peptide derived from the human mitochondrial/ER membrane-anchored NEET protein, Nutrient Autophagy Factor 1 (NAF-1; NAF-144-67), selectively permeates and kills human metastatic epithelial breast cancer cells (MDA-MB-231), but not control epithelial cells. As cancer cells alter their phenotype during growth and metastasis, we tested whether NAF-144–67 would also be efficient in killing other human epithelial breast cancer cells that may have a different phenotype. Here we report that NAF-144–67 is efficient in killing BT-549, Hs 578T, MDA-MB-436, and MDA-MB-453 breast cancer cells, but that MDA-MB-157 cells are resistant to it. Upon closer examination, we found that MDA-MB-157 cells display a high content of intracellular vesicles and cellular protrusions, compared to MDA-MB-231 cells, that could protect them from NAF-144–67. Inhibiting the formation of intracellular vesicles and dynamics of cellular protrusions of MDA-MB-157 cells, using a protein translation inhibitor (the antibiotic Cycloheximide), rendered these cells highly susceptible to NAF-144–67, suggesting that under certain conditions, the killing effect of CPPs could be augmented when they are applied in combination with an antibiotic or chemotherapy agent. These findings could prove important for the treatment of metastatic cancers with CPPs and/or treatment combinations that include CPPs.

Tumor-derived exosomes RNA expression profiling identifies the prognosis, immune characteristics, and treatment in HR+/HER2-breast cancer.

Exosomes play crucial roles in intercellular communication and are involved in the onset and progression of various types of cancers, including breast cancer. However, the RNA composition of breast cancer-derived exosomes has not been comprehensively explored. We conducted microarray assays on exosomes isolated from breast cancer and healthy breast epithelial cells from three patients with hormone receptor (HR) +/ human epidermal growth factor receptor (HER2) - breast cancer and identified 817 differentially expressed genes (DEGs). Among these, 315 upregulated tumor-derived exosome genes (UTEGs) were used to classify HR+/HER2- breast cancers into two categories, revealing a difference in survival rates between the groups. We developed and validated a novel prognostic exosome score (ES) model consisting of four UTEGs that provides a refined prognosis prediction in HR+/HER2-breast cancer. ES reflects various immune-related features, including somatic variation, immunogenicity, and tumor immune infiltrate composition. Our findings indicate a considerable positive correlation between the ES and drug sensitivity values for vincristine, paclitaxel, and docetaxel. However, ES was remarkably higher in the endocrine therapy non-responder group than in the responder group. Immunohistochemistry confirmed the remarkable expression of the four model genes in tumor tissues, and their expression in MCF-7 cell exosomes was higher than that in MCF10A cells, as verified via qPCR. In summary, tumor-derived exosome genes provide novel insights into the subtyping, prognosis, and treatment of HR+/HER2-breast cancer.

Expression of NORAD correlates with breast cancer aggressiveness and protects breast cancer cells from chemotherapy

The recently discovered human lncRNA NORAD is induced after DNA damage in a p53-dependent manner. It plays a critical role in the maintenance of genomic stability through interaction with Pumilio proteins, limiting the repression of their target mRNAs. Therefore, NORAD inactivation causes chromosomal instability and aneuploidy, which contributes to the accumulation of genetic abnormalities and tumorigenesis. NORAD has been detected in several types of cancer, including breast cancer, which is the most frequently diagnosed and the second-leading cause of cancer death in women. In the present study, we confirmed upregulated NORAD expression levels in a set of human epithelial breast cancer cell lines (MDA-MB-231, MDA-MB-436, and MDA-MB-468), which belong to the most aggressive subtypes (triple-negative breast cancer). These results are in line with previous data showing that high NORAD expression levels in basal-like tumors were associated with poor prognosis. Here, we demonstrate that NORAD downregulation sensitizes triple-negative breast cancer cells to chemotherapy, through a potential accumulation of genomic aberrations and an impaired capacity to signal DNA damage. These results show that NORAD may represent an unexploited neoadjuvant therapeutic target for chemotherapy-unresponsive breast cancer.

The Effects of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) on the Mechanical Properties of Breast Cancer Epithelial Cells

The Effects of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) on the Mechanical Properties of Breast Cancer Epithelial Cells

Embedded Bioprinting of Breast Tumor Cells and Organoids Using Low-Concentration Collagen-Based Bioinks.

Bioinks for 3D bioprinting of tumor models should not only meet printability requirements but also accurately maintain and support phenotypes of tumor surrounding cells to recapitulate key tumor hallmarks. Collagen is a major extracellular matrix protein for solid tumors, but low viscosity of collagen solution has made 3D bioprinted cancer models challenging. This work produces embedded, bioprinted breast cancer cells and tumor organoid models using low-concentration collagen I based bioinks. The biocompatible and physically crosslinked silk fibroin hydrogel is used to generate the support bath for the embedded 3D printing. The composition of the collagen I based bioink is optimized with a thermoresponsive hyaluronic acid-based polymer to maintain the phenotypes of both the noninvasive epithelial and invasive breast cancer cells, as well as cancer-associated fibroblasts. Mouse breast tumor organoids are bioprinted using optimized collagen bioink to mimic in vivo tumor morphology. A vascularized tumor model is also created using a similar strategy, with significantly enhanced vasculature formation under hypoxia. This study shows the great potential of embedded bioprinted breast tumor models utilizing a low-concentration collagen-based bioink for advancing the understanding of tumor cell biology and facilitating drug discovery research.

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.