Aggressive Breast Cancer Research Articles

Impact of prolactin treatment on enhancing the cellular responses of MCF7 breast cancer cells to tamoxifen treatment

Breast cancer remains one of the most challenging diseases to treat due to its heterogeneity, propensity to recur, capacity to spread to distant vital organs, and, ultimately, patient death. Estrogen receptor-positive illness comprises the most common breast cancer subtype. Preclinical progress is hampered by the scarcity of medication-naïve estrogen receptor-positive tumour models that recapitulate metastatic development and treatment resistance. It is becoming increasingly clear that loss of differentiation and increased cellular stemness and plasticity are important causes of cancer evolution, heterogeneity, recurrence, metastasis, and treatment failure. Therefore, it has been suggested that reprogramming cancer cell differentiation could offer an effective method of reversing cancer through terminal differentiation and maturation. In this context, the hormone prolactin is well recognized for its pivotal involvement in the development of the mammary glands lobuloalveolar tissue and the terminal differentiation that drives the production of the milk protein gene and lactation. Additionally, numerous studies have examined the engagement of prolactin in breast cancer as a differentiation player that resulted in the ablation of tumour growth and progression. Here, we showed that a pre-treatment of the estrogen-positive breast cancer cell line with prolactin led to a considerable improvement in the sensitivity of this cancer cell to Tamoxifen endocrine therapy. We also showed a favourable prognostic value of prolactin receptors/estrogen receptors 1 (or alpha) co-expression on breast cancer patients outcomes, and this co-expression is highly correlated with the well-differentiated breast tumour type. Our results revealed a fruitful aspect of the effects of prolactin in improving the responses of breast cancer cells to conventional endocrine therapy. Moreover, these findings further validated the ability of prolactin as a persuader of a more differentiated and less aggressive breast cancer phenotype. Hence, it suggested a potential implication of prolactin as a therapeutic candidate.

A New Heteroleptic Zn(II) Complex with Schiff Bases Sensitizes Triple-Negative Breast Cancer Cells to Doxorubicin and Paclitaxel

Background/Objectives: Triple-negative breast cancer (TNBC) is the most challenging molecular subtype of breast cancer (BC) in clinical practice, associated with a worse prognosis due to limited treatment strategies and its insensitivity to conventional drugs. Zinc is an important trace element for homeostasis, and its Schiff base metal complexes have shown promise in treating advanced tumors. In this study, four new heteroleptic Zn(II) complexes (1–4) with Schiff bases were synthesized, characterized, and evaluated for their activity in BC cells. Methods: Compounds were synthesized, characterized, and their crystal structures were determined. Biological activity was assessed using MTT, clonogenic, scratch wound healing, caspase 3 and 8 activity, qPCR, and chemosensitization assays. Results: The complexes exhibited cytotoxicity against MCF-7 (luminal BC), MDA-MB-453 (HER2-positive BC), and MDA-MB-231 (TNBC) cell lines, with IC50 values ranging from 0.01 to 20 µM. Complex 4 showed reduced cytotoxicity toward non-tumor cell lines. This, complexation with Zn(II) increased the cytotoxicity of the ligands, a trend not observed for complexes 1–3. Due to its favorable profile, complex 4 was selected for further assays, in which it inhibited colony formation and the cell migration of TNBC cells in a dose-dependent manner. Furthermore, this compound induced cell death independently of caspases, decreasing the activity of caspase 8. Interestingly, complex 4 sensitized TBNC cells to doxorubicin and paclitaxel, possibly modulating the epithelial–mesenchymal transition mechanism, as evidenced by increased CDH1 expression. Conclusions: Results suggest the potential of complex 4 in sensitizing aggressive BC cells to chemotherapy, proving to be a promising alternative in cases of therapeutic failure.

FAHD1 and mitochondrial metabolism: a decade of pioneering discoveries.

This review consolidates a decade of research on fumarylacetoacetate hydrolase domain containing protein 1 (FAHD1), a mitochondrial oxaloacetate tautomerase and decarboxylase with profound implications in cellular metabolism. Despite its critical role as a regulator in mitochondrial metabolism, FAHD1 has remained an often-overlooked enzyme in broader discussions of mitochondrial function. After more than 12 years of research, it is increasingly clear that FAHD1's contributions to cellular metabolism, oxidative stress regulation, and disease processes such as cancer and aging warrant recognition in both textbooks and comprehensive reviews. The review delves into the broader implications of FAHD1 in mitochondrial function, emphasizing its roles in mitigating reactive oxygen species (ROS) levels and regulating complex II activity, particularly in cancer cells. This enzyme's significance is further highlighted in the context of aging, where FAHD1's activity has been shown to influence cellular senescence, mitochondrial quality control, and the aging process. Moreover, FAHD1's involvement in glutamine metabolism and its impact on cancer cell proliferation, particularly in aggressive breast cancer subtypes, underscores its potential as a therapeutic target. In addition to providing a comprehensive account of FAHD1's biochemical properties and structural insights, the review integrates emerging hypotheses regarding its role in metabolic reprogramming, immune regulation, and mitochondrial dynamics. By establishing a detailed understanding of FAHD1's physiological roles and therapeutic potential, this work advocates for FAHD1's recognition in foundational texts and resources, marking a pivotal step in its integration into mainstream metabolic research and clinical applications in treating metabolic disorders, cancer, and age-related diseases.

Targeting Nudix Hydrolase 5 with Bioactive Flavonoids: Molecular Dynamics and Docking Studies for Breast Cancer Therapy.

Breast cancer (BC) is the most prevalent malignancy among women globally and the leading cause of cancer-related mortality. Consequently, there is an urgent need for new, effective treatment strategies for breast cancer. Research has shown that the enzyme nudix hydrolase 5 (NUDT5) plays a critical role in promoting breast cancer aggressiveness and serves as a key regulator of oncogenic pathways. The development of NUDT5 inhibitors presents a viable strategy for enhancing treatment results in managing BC. The ability of the flavonoids to modulate key biochemical pathways and improve therapeutic outcomes highlights their promise in developing novel breast cancer treatments. Hence, the main objective of the present investigation is to identify the potential interaction of structurally diverse bioactive flavonoids with the active site of the target NUDT5. Our docking analysis revealed that the flavonoids such as naringin and genistein have shown a significant binding association with residues Arg51, Asp60, Gln82, Arg84, Ala96, Leu98, Glu112, Glu116, Met132, Cys139, Ile141, and Glu166 of NUDT5, suggesting its potential as a potent inhibitor. The stabilizing effects of these leads (naringin and genistein) were further validated using molecular dynamics investigations, including RMSD, RMRF, Rg, SASA, PCA, and FEL. The results of the MD simulation studies evidenced a more significant interaction between genistein and NUDT5, indicating a steady and robust affinity, making genistein a more promising inhibitor. In conclusion, the flavonoid genistein has a strong potential as a therapeutic agent for targeting NUDT5 in breast cancer treatment making it viable candidates for further preclinical and clinical investigations.

Innovative Nanomaterials for Targeting Hypoxia to Improve Treatment for Triple-negative Breast Cancer.

Triple-negative breast cancer (TNBC) is an aggressive breast cancer with a high rate of metastases, a short overall survival time, and a poor response to targeted therapy. Improving tumor hypoxia by lowering the oxygen consumption rate of breast tumor cells is a powerful strategy. A viable way to address this issue is to improve therapeutic efficacy by improving the effectiveness of radiation and overcoming drug resistance in TNBC treatment by controlling hypoxia in the tumor microenvironment. The failure of radiation and chemotherapy in TNBC is frequently caused by hypoxia. In TNBC therapy, novel nanomaterials are used for oxygen delivery or generation to affect the tumor microenvironment to improve the effects of ionizing radiation using nanoplatforms. One of the growing fields is novel nano-based drug delivery devices for hypoxic regions and hypoxia- inducible factor-1 (HIF1) targeted therapeutics. Biocompatible nanoparticles may be used in the treatment of TNBC patients in the clinic. Because of the rising market and competition, intellectual property rights (IPR), patents, and tactics may be critically considered. To better comprehend the current state of IPR and patents in cancer nanotechnology, this overview examines recent advances and sophisticated protection measures in this area.

Curcumin alleviates the aggressiveness of breast cancer through inhibiting cell adhesion mediated by TEAD4-fibronectin axis

Breast cancer (BC) ranks first among women in the world and metastasis is the main reason of cancer death. TEA domain transcription factor 4 (TEAD4) plays an important role in TEAD family members in the Hippo signaling pathway, and its pro-cancer effect is gradually being discovered, but little is known about the mechanism of TEAD4 regulating tumor adhesion and metastasis. Curcumin is an active polyphenol compound with anti-inflammatory and anti-tumor properties. However, its effects and the underlying mechanisms on BC metastasis remain unknown. Here, we show that curcumin reduced the abilities of migration and invasion of BC cells as well as lung metastasis of BC in nude mice by TEAD4 induced. TEAD4 could regulate the transcription level of adhesion molecule Fibronectin (FN1), which is an important component of extracellular matrix participating in tumor cell adhesion and migration processes, and the binding of TEAD4 to the FN1 promoter was suppressed by curcumin. Furthermore, the metastatic mobility was significantly reduced in FN1 knockout BC cells, and FN1 knockout can reverse metastatic potential of TEAD4 overexpressed cells. Our work demonstrates that TEAD4 could promote cell adhesion and migration by binding with FN1 promoter and suggested that TEAD4-FN1 axis in tumor microenvironment is expected to become a potential target for alleviating metastasis of BC of curcumin.Abbreviations: Breast cancer (BC); Bicinchoninic acid (BCA); Bovine Serum Albumin (BSA); Curcumin at 20 μM (Cur20) and 30 μM (Cur30); Dimethyl −sulfoxide (DMSO); Dulbecco’s Modified Eagle’s Medium (DMEM); Extracellular Matrix (ECM); Fetal bovine serum (FBS); Fibronectin (FN1); Immunohistochemical (IHC); Minimum Essential Medium (MEM); The negative control with infected blank lentivirus (NC); Phenylmethanesulfonyl fluoride (PMSF); Polyvinylidene difluoride (PVDF); Real-time quantitative reverse transcription (RT-qPCR); single guide RNA (sgRNA); short hairpin RNA (shRNA); Human TEAD4 shRNA (shTEAD4); Transcriptional coactivator with PDZ-binding motif (TAZ); TEA domain transcription factor 4 (TEAD4); TEAD4 overexpressed (TEAD4-OE); Vascular endothelial growth factor (VEGF); Yes-associated protein (YAP);

FMNL3 Promotes Migration and Invasion of Breast Cancer Cells via Inhibiting Rad23B-Induced Ubiquitination of Twist1.

Breast cancer is a heterogeneous malignant tumor, and its high metastasis rate depends on the abnormal activation of cell dynamics. Formin-like protein 3 (FMNL3) plays an important role in the formation of various cytoskeletons that participate in cell movement. The objective of this study was to explore the function of FMNL3 in breast cancer progression and endeavor to reveal the molecular mechanism of this phenomenon. We found that FMNL3 was abnormally highly expressed in aggressive breast cancer cells and tissues, and it significantly inhibited E-cadherin expression. FMNL3 could specifically interact with Twist1 rather than other epithelial-mesenchymal transition transcription factors (EMT-TFs). We also found that FMNL3 enhanced the repressive effect of Twist1 on CDH1 transcription in breast cancer cells. Further mechanism studies showed that FMNL3 suppressed the ubiquitin degradation of Twist1 by inhibiting the interaction between Twist1 and Rad23B, the ubiquitin transfer protein of Twist1. In vitro functional experiments, it was confirmed that FMNL3 promoted the migration and invasion of breast cancer cells by regulating Twist1. Furthermore, Twist1 could directly bind to the fmnl3 promoter to facilitate FMNL3 transcription. To conclude, this study indicated that FMNL3 acted as a pro-metastasis factor in breast cancer by promoting Twist1 stability to suppress CDH1 transcription.

CD74 promotes the formation of an immunosuppressive tumor microenvironment in triple-negative breast cancer in mice by inducing the expansion of tolerogenic dendritic cells and regulatory B cells.

CD74 is a cell-surface receptor for the cytokine macrophage migration inhibitory factor (MIF). MIF binding to CD74 induces a signaling cascade resulting in the release of its cytosolic intracellular domain (CD74-ICD), which regulates transcription in naïve B and chronic lymphocytic leukemia (CLL) cells. In the current study, we investigated the role of CD74 in the regulation of the immunosuppressive tumor microenvironment (TME) in triple-negative breast cancer (TNBC). TNBC is the most aggressive breast cancer subtype and is characterized by massive infiltration of immune cells to the tumor microenvironment, making this tumor a good candidate for immunotherapy. The tumor and immune cells in TNBC express high levels of CD74; however, the function of this receptor in the tumor environment has not been extensively characterized. Regulatory B cells (Bregs) and tolerogenic dendritic cells) tol-DCs (were previously shown to attenuate the antitumor immune response in TNBC. Here, we demonstrate that CD74 enhances tumor growth by inducing the expansion of tumor-infiltrating tol-DCs and Bregs. Utilizing CD74-KO mice, Cre-flox mice lacking CD74 in CD23+ mature B cells, mice lacking CD74 in the CD11c+ population, and a CD74 inhibitor (DRQ), we elucidate the mechanism by which CD74 inhibits antitumor immunity. MIF secreted from the tumor cells activates CD74 expressed on DCs. This activation induces the binding of CD74-ICD to the SP1 promotor, resulting in the up-regulation of SP1 expression. SP1 binds the IL-1β promotor, leading to the down-regulation of its transcription. The reduced levels of IL-1β lead to decreased antitumor activity by allowing expansion of the tol-DC, which induces the expansion of the Breg population, supporting the cross-talk between these 2 populations. Taken together, these results suggest that CD74+ CD11c+ DCs are the dominant cell type involved in the regulation of TNBC progression. These findings indicate that CD74 might serve as a novel therapeutic target in TNBC.

Combination strategies with PARP inhibitors in BRCA-mutated triple-negative breast cancer: overcoming resistance mechanisms.

Triple-negative breast cancer (TNBC) is a particularly aggressive breast cancer subtype, characterised by a higher incidence in younger women, rapid metastasis, and a generally poor prognosis. Patients with TNBC and BRCA mutations face additional therapeutic challenges due to the cancer's intrinsic resistance to conventional therapies. Poly (ADP-ribose) polymerase inhibitors (PARPis) have emerged as a promising targeted treatment for BRCA-mutated TNBC, exploiting vulnerabilities in the homologous recombination repair (HRR) pathway. However, despite initial success, the efficacy of PARPis is often compromised by the development of resistance mechanisms, including HRR restoration, stabilisation of replication forks, reduced PARP1 trapping, and drug efflux. This review explores latest breakthroughs in overcoming PARPi resistance through combination therapies. These strategies include the integration of PARPis with chemotherapy, immunotherapy, antibody-drug conjugates, and PI3K/AKT pathway inhibitors. These combinations aim to enhance the therapeutic efficacy of PARPis by targeting multiple cancer progression pathways. The review also discusses the evolving role of PARPis within the broader treatment paradigm for BRCA-mutated TNBC, emphasising the need for ongoing research and clinical trials to optimise combination strategies. By tackling the challenges associated with PARPi resistance and exploring novel combination therapies, this review sheds light on the future possibilities for improving outcomes for patients with BRCA-mutated TNBC.

Perspectives on the potential application of microRNAs in the diagnosis and treatment of triple-negative breast cancer

Abstract Triple-negative breast cancer (TNBC) is currently the most heterogeneous and aggressive breast cancer type. It has a high recurrence rate, poor clinical prospects, and lack of predictive markers and potential treatment options. Dysregulated microRNAs (miRNAs) are involved in various cellular processes in TNBC. Moreover, variations in the miRNA levels in TNBC may act as a dependable indicator for predicting the effectiveness and specificity of treatments. Currently, the application of miRNAs for breast cancer therapy is primarily in the preclinical stage, with a focus on identifying highly specific and sensitive miRNAs that could offer new possibilities for early diagnosis, clinical treatment, and prognostic monitoring of TNBC.

MiR-23b-3p, miR-126-3p and GAS5 delivered by extracellular vesicles inhibit breast cancer xenografts in zebrafish

BackgroundExtracellular vesicles (EVs) are a group of nanoscale cell-derived membranous structures secreted by all cell types, containing molecular cargoes involved in intercellular communication. EVs can be used to mimic “nature’s delivery system” to transport nucleic acids, peptides, lipids, and metabolites to target recipient cells. EVs offer a range of advantages over traditional synthetic carriers, thus paving the way for innovative drug delivery approaches that can be used in different diseases, including cancer. Here, by using breast cancer (BC) cells treated with the multi-kinase inhibitor sorafenib, we generated EVs enriched in specific non-coding RNAs (miR-23b-3p, miR-126-3p, and the long ncRNA GAS5) and investigated their potential impact on the aggressive properties of the BC in vitro and in vivo using zebrafish.MethodsEVs were collected from 4 different BC cell lines (HCC1937, MDA-MB-231, MCF-7, and MDA-MB-453) and characterized by western blotting, transmission electron microscopy and nanoparticle tracking analysis. Levels of encapsulated miR-23b-3p, miR-126-3p, and GAS5 were quantified by ddPCR. The role of the EVs as carriers of ncRNAs in vivo was established by injecting MDA-MB-231 and MDA-MB-453 cells into zebrafish embryos followed by EV-based treatment of the xenografts with EVs rich in miR-23b-3p, miR-126-3p and GAS5.ResultsddPCR analysis revealed elevated levels of miR-23b-3p, miR-126-3p, and GAS5, encapsulated in the EVs released by the aforementioned cell lines, following sorafenib treatment. The use of EVs as carriers of these specific ncRNAs in the treatment of BC cells resulted in a significant increase in the expression levels of the three ncRNAs along with the inhibition of cellular proliferation in vitro. In vivo experiments demonstrated a remarkable reduction of xenograft tumor area, suppression of angiogenesis, and decreased number of micrometastasis in the tails after administration of EVs enriched with these ncRNAs.ConclusionsOur study demonstrated that sorafenib-induced EVs, enriched with specific tumor-suppressor ncRNAs, can effectively inhibit the aggressive BC characteristics in vitro and in vivo. Our findings indicate an alternative way to enrich EVs with specific tumor-suppressor ncRNAs by treating the cells with an anticancer drug and support the development of new potential experimental molecular approaches to target the aggressive properties of cancer cells.

Chaga Mushroom Triterpenoids Inhibit Dihydrofolate Reductase and Act Synergistically with Conventional Therapies in Breast Cancer.

Inonotus obliquus (Chaga) is a medicinal mushroom with several pharmacological properties that is used as a tea in traditional Chinese medicine. In this study, Chaga water extract was digested in vitro to mimic the natural processing and absorption of its biocomponents when it is consumed as functional beverage, and its anticancer activities were evaluated in breast cancer (BC) cell lines, representing HER2-positive and triple-negative subtypes. After chemical characterization by liquid chromatography/mass spectrometry (HR-QTOF) analysis, the effect of Chaga biocomponents on cell viability and cell cycle progression was assessed by MTT assay, FACS analysis, and Western blot. Dihydrofolate reductase (DHFR) activity was measured by an enzymatic assay. Four highly bioactive triterpenoids (inotodiol, trametenolic acid, 3-hydroxy-lanosta-8,24-dien-21-al, and betulin) were identified as the main components, able to decrease BC cell viability and block the cell cycle in G0/G1 by inducing the downregulation of cyclin D1, CDK4, cyclin E, and phosphorylated retinoblastoma protein. DHFR was identified as their crucial target. Moreover, bioactive Chaga components exerted a synergistic action with cisplatin and with trastuzumab in SK-BR-3 cells by inhibiting both HER2 and HER1 activation and displayed an immunomodulatory effect. Thus, Inonotus obliquus represents a source of triterpenoids that are effective against aggressive BC subtypes and display properties of targeted drugs.

Abstract B017: The double-edged sword of cystatin B in luminal-like and triple-negative breast cancers

Abstract The complex protease network of cathepsins and their inhibitors, cystatins, intricately regulates numerous cellular processes, and its dysregulation is frequently implicated in cancer pathogenesis. Abnormal cathepsin activity, subcellular localization, and a disrupted balance between cathepsins and cystatins have been identified in cancer. While diminished cystatin levels typically correlate with more aggressive cancer phenotypes, few findings challenge this paradigm. In this context, our latest study revealed elevated expression of cystatin B (CSTB) in luminal-like breast cancer (BC) patients experiencing relapse within five years post-surgery. Furthermore, computational analysis of publicly available datasets supports our idea of CSTB as a potential negative prognostic biomarker in luminal-like tumors. Intriguingly, a converse relationship is observed in basal-like/triple negative BC patients, where increased CSTB expression seems to be associated with improved prognosis. In addition, the cysteine/cathepsin network intricately intersects with immune functions, adding another layer of complexity. Cathepsins are indeed involved in the induction of an efficient anti-tumor immune response, being key in antigen processing and presentation by antigen-presenting cells and in the cytotoxic activities of NK and T cells. On the other hand, myeloid cells rely on cathepsins for the degradation of ECM proteins that may favor migration and invasion of tumor cells. All these pieces of evidence led to the hypothesis that the functional impact of CSTB may vary depending on the tumor intrinsic characteristics and on its microenvironment and therefore that CSTB might fulfill distinct functional roles in luminal-like and basal-like BC. To start addressing our hypothesis, we silenced CSTB expression in the 4T1 mouse cell line, a TNBC model spontaneously metastasizing to the lungs upon intra-mammary fat pad injection. Preliminary in vivo experiments to investigate the effect on primary tumor growth and metastatic dissemination showed that 4T1 shCSTB lines were indeed characterized by increased tumor growth and metastatic dissemination than the two sh-control lines. Interestingly, expression of stemness- related genes (Nanog, Sox2 and Oct4) were up-modulated upon CTSB silencing, in agreement with a more aggressive phenotype. On the other hand, preliminary in vitro assays with a luminal- like BC cell line support the hypothesis of an opposite effect of CSTB down-modulation in luminal BC subtype. Moreover, CSTB silencing in RAW264.7 macrophagic cell line, impaired M1 in vitro polarization, while it did not appear to affect M2 skewing. Overall, although preliminary, these data suggest that CSTB may affect BC aggressiveness by both interfering with tumor cell-intrinsic features and microenviroment-related traits. Citation Format: Anna Zaccaria, Chiara Ratti, Laura Botti, Sabina Sangaletti, Mario P. Colombo, Claudia Chiodoni. The double-edged sword of cystatin B in luminal-like and triple-negative breast cancers [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr B017.

Drug-loaded nanomaterial kills aggressive breast cancer cells

Drug-loaded nanomaterial kills aggressive breast cancer cells

Abstract B013: Investigation of a novel lncRNA, TROLL-9, in breast cancer formation and progression

Abstract Breast cancer (BC) is the most diagnosed cancer and the second leading cancer-related cause of mortality among women in the US. Despite advances in treatment, BC remains a challenge due to its metastatic potential. The most aggressive BC subtype, triple negative (TN), often harbors mutations in the tumor suppressor gene, p53. One of the effects of mutant p53 involves the inhibition of the tumor and metastatic suppressive functions of TAp63, a p53 family member. Loss of TAp63 leads to the formation of metastatic mammary adenocarcinomas in mice, in part through the regulation of a group of nine long non-coding RNAs (lncRNAs), that we identified and named TAp63 regulated oncogenic lncRNAs (TROLLs). We previously characterized two TROLLs, TROLL-2 and TROLL-3, as markers of tumor progression in multiple cancer types via the activation of the AKT pathway. Currently we are investigating the role of another member, TROLL-9. To investigate the biological role of TROLL-9, we performed in vivo experiments using preclinical mouse models. Specifically, MCF-DCIS, MCF-CA1D, and MDA-MB-231 triple negative breast cancer (TNBC) cells constitutively expressing TROLL-9 were generated and utilized for two mouse models: orthotopic xenografts for primary tumor growth and spontaneous metastasis. The former was designed to identify the potential role of TROLL-9 in tumor formation, whereas the latter involved the resection of a primary tumor and monitoring for metastases via bioluminescence imaging. Notably, TROLL-9 overexpression led to increased formation of lung and livers metastases in all these models, suggesting a role for TROLL-9 in the metastatic cascade. In order to elucidate the mechanism of function of TROLL-9, two complementary approaches were used. Firstly, pulldown using MS2-TRAP followed by mass spectrometry (MS) was performed and led to the identification of putative protein interactors. In parallel, Laser Capture Microscopy (LCM) of the lung metastases followed by RNA-sequencing was used to assess for any gene expression changes due to TROLL-9 overexpression. Integration of the two datasets is currently being performed to unveil the network of genes and proteins perturbed by TROLL-9. Furthermore, to understand the relevance in BC patients, TROLL-9 expression levels were analyzed in the TCGA BC dataset. Interestingly, differences in TROLL-9 levels across BC subtypes were observed, thus supporting its putative role in TNBC. Overall, our data suggest a role for TROLL-9 in BC progression. Our findings provide evidence for further characterizing its mechanism of function as a potential therapeutic target for the treatment of invasive BC, particularly TNBC harboring TP53 mutations. Citation Format: Avani A Deshpande, Marco Napoli, John H Lockhart, Christina L Carr, Jaden R Baldwin, Elsa R Flores. Investigation of a novel lncRNA, TROLL-9, in breast cancer formation and progression [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: RNAs as Drivers, Targets, and Therapeutics in Cancer; 2024 Nov 14-17; Bellevue, Washington. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(11_Suppl):Abstract nr B013.

Radiologic imaging biomarkers in triple-negative breast cancer: a literature review about the role of artificial intelligence and the way forward

Abstract Breast cancer is one of the most common and deadly cancers in women. Triple-negative breast cancer (TNBC) accounts for approximately 10-15% of breast cancer diagnoses and is an aggressive molecular breast cancer subtype associated with important challenges in its diagnosis, treatment, and prognostication. This poses an urgent need for developing more effective and personalized imaging biomarkers for TNBC. Toward this direction, artificial intelligence (AI) for radiologic imaging holds a prominent role, leveraging unique advantages of radiologic breast images, being used routinely for TNBC diagnosis, staging, and treatment planning, and offering high-resolution whole-tumor visualization, combined with the immense potential of AI to elucidate anatomical and functional properties of tumors that may not be easily perceived by the human eye. In this review, we synthesize the current state-of-the-art radiologic imaging applications of AI in assisting TNBC diagnosis, treatment, and prognostication. Our goal is to provide a comprehensive overview of radiomic and deep-learning-based AI developments and their impact on advancing TNBC management over the last decade (2013-2024). For completeness of the review, we start with a brief introduction of AI, radiomics and deep learning. Next, we focus on clinically relevant AI-based diagnostic, predictive and prognostic models for radiologic breast images evaluated in TNBC. We conclude with opportunities and future directions for AI towards advancing diagnosis, treatment response predictions and prognostic evaluations for TNBC.

Lower FGFR2 mRNA Expression and Higher Levels of FGFR2 IIIc in HER2-Positive Breast Cancer.

Fibroblast growth factor receptor 2 (FGFR2) has been associated with breast cancer. We performed in silico analyses to investigate the FGFR2 mRNA expression and splice variants associated with breast cancer subtypes. Online databases, including cBioPortal and TCGA SpliceSeq, were used to examine the association between the FGFR2 expression and splice variants with breast cancer subtypes. A higher FGFR2 mRNA was significantly associated with luminal, oestrogen receptor (ER)-positive breast cancers, and invasive lobular carcinomas, whereas a lower FGFR2 was associated with human epidermal growth factor receptor 2 (HER2)-positive breast cancer and invasive ductal carcinomas. The epithelial alternatively spliced FGFR2 IIIb isoform was significantly enriched in ER+ breast cancer, while the mesenchymal FGFR2 IIIc isoform was significantly prevalent in HER2+ cancer. Increased levels of FGFR2 and IIIb splice isoforms are associated with less aggressive breast cancer phenotypes, while decreased levels of FGFR2 and increased IIIc splice isoform are associated with more aggressive phenotypes.

Deciphering the Role of ASPM in Breast Cancer: A Comprehensive Multicohort Study.

Assembly factor for spindle microtubules (ASPM) has gained significant attention in cancer research due to its association with tumor growth and progression. Through the analysis of large-scale genomic datasets, ASPM has been identified as the top upregulated gene in breast cancer (BC), characterized by high proliferation. This multicohort study aimed to investigate the clinicopathological and prognostic significance of ASPM mRNA and protein expression in BC. ASPM mRNA expression was assessed using the Cancer Genome Atlas (TCGA) BC cohort and has been further validated in the Molecular Taxonomy of BC International Consortium (METABRIC) (n = 1980), The Uppsala cohort (n = 249), in addition to the combined multicentric cohort (n = 7252). ASPM protein expression was evaluated in a large BC cohort (n = 1300) using immunohistochemistry. The correlations between ASPM expression, clinicopathological parameters, molecular subtypes and outcome were assessed. The response to taxane treatment was compared to the clinical prognosis of ASPM using the ROC plotter. High ASPM mRNA and protein expression were significantly associated with aggressive BC features and poor survival across all cohorts. The association with poor outcomes was maintained in the adjuvant chemotherapy and radio-therapy-treated patients. Responders to taxane treatment showed significantly elevated ASPM levels compared to non-responders. High ASPM expression predicts poor prognosis in BC. It may play a role in treatment resistance within a specific subgroup of patients. Further clinical trials are warranted to explore the potential of ASPM as a target for therapeutic interventions in cancer.

Prognostic role of Androgen Receptor splice variant 7 (AR-V7) in the pathogenesis of breast cancer

BackgroundThe Androgen Receptor (AR) has emerged as an endocrine therapy target in Breast Cancer, exhibiting up to 80% expression in clinical cases. AR-V7, a constitutively activated splice variant of AR with a truncated ligand-binding domain (LBD), demonstrates ligand-independent transcriptional activity and resistance to nonsteroidal antiandrogens like Bicalutamide or Enzalutamide, targeting the LBD. In metastatic prostate cancer, elevated AR-V7 levels lead to therapeutic resistance and increased metastasis.MethodsIn this study, we evaluated the expression of AR and AR-V7 in cell lines and a cohort of 89 patients undergoing surgical intervention for treatment-naïve breast cancer. Further clinicopathological correlations and survival analysis were performed to evaluate the relationship between the AR and AR-V7 expression and clinical outcomes.ResultsAR-V7/AR-FL ratio was elevated in the TNBC cell line and downregulation of AR-FL upon AR antagonists’ treatment led to a compensatory increase in AR-V7. Clinical samples showed significantly elevated expression of AR and AR-V7 in tumors compared to control cases. Further clinicopathological correlation revealed aggressive clinical traits, higher pathological grades, and poor survival with AR-V7 expression.ConclusionsOur study unravels AR-V7 as a marker for poor clinical outcomes, predicting breast cancer aggressiveness, and encourages consideration of AR-V7 as a probable target for therapeutic intervention.

Targeting APC/C Ubiquitin E3-Ligase Activation with Pyrimidinethylcarbamate Apcin Analogues for the Treatment of Breast Cancer.

Activation of the ubiquitin ligase APC/C by the protein Cdc20 is an essential requirement for proper cell division in higher organisms, including humans. APC/C is the ultimate effector of the Spindle Assembly Checkpoint (SAC), the signalling system that monitors the proper attachment of chromosomes to microtubules during cell division. Defects in this process result in genome instability and cancer. Interfering with APC/C substrate ubiquitylation in cancer cells delays mitotic exit, which induces cell death. Therefore, impairing APC/C function represents an opportunity for the treatment of cancer and malignancies associated with SAC dysregulation. In this study, we report a new class of pyrimidinethylcarbamate apcin analogues that interfere with APC/C activity in 2D and 3D breast cancer cells. The new pyrimidinethylcarbamate apcin analogues exhibited higher cytotoxicity than apcin in all breast cancer cell subtypes investigated, with much lower cytotoxicity observed in fibroblasts and RPE-1 cells. Further molecular rationalisation of apcin and its derivatives was conducted using molecular docking studies. These structural modifications selected from the in silico studies provide a rational basis for the development of more potent chemotypes to treat highly aggressive breast cancer and possibly other aggressive tumour types of diverse tissue origins.