Targeting PI3K/AKT/mTOR Pathway in Breast Cancer: From Biology to Clinical Challenges

Total flavonoids of litchi seed inhibit breast cancer metastasis by regulating the PI3K/AKT/mTOR and MAPKs signaling pathways

CONTEXT

Total flavonoids from Litchi chinensis Sonn. (Sapindaceae) seeds (TFLS) effectively attenuate stem cell-like properties in breast cancer cells. However, their pharmacological effects and mechanisms in suppressing breast cancer metastasis remain unclear.

OBJECTIVE

This study aimed to elucidate the inhibitory effects and underlying mechanisms of TFLS on breast cancer metastasis.

MATERIALS AND METHODS

The antiproliferative, migratory, and invasive activities of breast cancer cells following TFLS treatment were evaluated using CCK-8, wound-healing, and transwell assays. The epithelial-mesenchymal transition (EMT) biomarkers were evaluated via Western blot analysis. The anti-metastatic effects of TFLS were further validated in vivo using zebrafish and mouse models. Network pharmacology methodology was utilized to predict potential targets and signaling pathways, which were subsequently corroborated by Western blot. Potential active compounds were identified through molecular docking, and the chemical constituents of TFLS were analyzed and characterized using UPLC-QTOF/MS.

RESULTS

TFLS suppressed the proliferation of MDA-MB-231 and MDA-MB-468 cells, with IC50 values of 44.47 μg/mL and 37.35 μg/mL at 72 h, respectively. It effectively suppressed breast cancer metastasis in vitro, demonstrated by a marked reduction in cellular motility and invasiveness, alongside the reversal of EMT. Consistent with pathway enrichment analysis, network pharmacology revealed that TFLS reduced the phosphorylation levels of PI3K, AKT, mTOR, JNK, ERK, and p38 in breast cancer cells. Molecular docking identified seven potential active ingredients, and UPLC-MS/MS confirmed the presence of key compounds, including procyanidin A2.

DISCUSSION AND CONCLUSION

TFLS effectively inhibits breast cancer cell proliferation, migration, and invasion in vitro by reversing the EMT phenotype, while suppressing metastasis in vivo. These effects are likely mediated via the attenuation of the PI3K/AKT/mTOR and MAPK signaling pathways.

Strategic advancements in targeting the PI3K/AKT/mTOR pathway for Breast cancer therapy

Breast cancer (BC) is a complex disease that affects millions of women worldwide. Its growing impact calls for advanced treatment strategies to improve patient outcomes. The PI3K/AKT/mTOR pathway is a key focus in BC therapy because it plays a major role in important processes like tumor growth, survival, and resistance to treatment. Targeting this pathway could lead to better treatment options and outcomes. The present review explores how the PI3K/AKT/mTOR pathway becomes dysregulated in BC, focusing on the genetic changes like PIK3CA mutations and PTEN loss that leads to its aggravation. Current treatment options include the use of inhibitors targeting PI3K, AKT, and mTOR with combination therapies showing promise in overcoming drug resistance and improving effectiveness. Looking ahead, next-generation inhibitors and personalized treatment plans guided by biomarker analysis may provide more accurate and effective options for patients. Integrating these pathway inhibitors with immunotherapy offers an exciting opportunity to boost anti-tumor responses and improve survival rates. This review offers a comprehensive summary of the current progress in targeting the PI3K/AKT/mTOR pathway in BC. It highlights future research directions and therapeutic strategies aimed at enhancing patient outcomes and quality of life.

Cyclin-dependent kinase 4 and 6 inhibitors in breast cancer treatment

Breast cancer is the second largest cancer in the world, and it has highest mortality rate in women worldwide. The aberrant activation of the cyclin-dependent kinase 4 and 6 (CDK4/6) pathway plays an important role in uncontrolled breast cancer cell proliferation. Therefore, targeting CDK4/6 to improve overall survival rates has been a strong interest in breast cancer therapeutics. Till date, four CDK4/6 inhibitors have been developed and approved for hormone receptor-positive and human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer therapies with great success. However, acquired resistance to CDK4/6 inhibitors has emerged and limits their effectiveness in breast cancer. In this review, we systematically discussed the mechanisms of resistance to CDK4/6 inhibitors including the cell cycle-specific and cell cycle-nonspecific mechanisms. Also, we analyzed combination strategies with other signaling inhibitors in clinical and preclinical settings that further expand the clinical application of CDK4/6 inhibitors in future breast cancer therapies.

Mechanism of ethyl acetate fraction of Amorphophallus konjac against breast cancer based on network pharmacology, molecular docking and experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

Amorphophallus konjac (Sheliugu), a medicinal and edible herb from East China and regions south of the Yangtze River, exhibits significant antitumor activity. However, its active constituents and mechanisms remain poorly understood.

AIMS OF THE STUDY

This study explores the therapeutic effects of the konjac ethyl acetate fraction (KEAF) in triple-negative breast cancer (TNBC) and elucidates its underlying mechanisms.

MATERIALS AND METHODS

UPLC-MS/MS identified KEAF's chemical components, and network pharmacology determined its key targets in TNBC. Survival curves of essential genes were analyzed using UALCAN, bc-GenExMiner, and Kaplan-Meier plotter databases. Protein expression and prognostic data identified TNBC-linked genes. Molecular docking assessed binding affinities of KEAF's bioactive components with these genes. In vitro experiments validated KEAF's effects on proliferation, migration, cell cycle regulation, and apoptosis.

RESULTS

KEAF contained 15 active compounds and 146 principal targets, with eight key targets identified: TP53, EGFR, AKT1, MYC, STAT3, HIF1A, ESR1, and JUN. GO and KEGG enrichment analyses highlighted the PI3K/Akt signaling pathway as central to KEAF's therapeutic effects. Protein expression and prognostic studies confirmed EGFR and ESR1 as critical in TNBC progression. Molecular docking revealed strong binding of scutellarein and genistein to EGFR and ESR1 (T score >5). In vitro, KEAF inhibited MDA-MB-231 cell proliferation and migration, modulated the cell cycle, and induced apoptosis by downregulating PI3K/Akt signaling.

CONCLUSION

Scutellarein and genistein in KEAF exhibit therapeutic potential against TNBC by targeting EGFR and ESR1 and suppressing the PI3K/Akt signaling pathway.

Liquiritin as a Tumor Suppressor Prevents the Development of Breast Cancer via the Epidermal Growth Factor Receptor/Mitogen-Activated Protein Kinase 8 Signaling Pathway

Liquiritin, a key component extracted from Glycyrrhiza radix, exhibits a variety of physiological effects. This study investigates the role of liquiritin in the progression of breast cancer. This investigation conducted experiments using two breast cancer cell lines treated with varying concentrations of liquiritin, further validating our findings in vivo. Bioinformatics analysis was used to identify the pathways potentially regulated by liquiritin in breast cancer. The results indicated that the epidermal growth factor receptor (EGFR) and mitogen-activated protein kinase 8 (MAPK8) are potential downstream factors regulated by liquiritin in breast cancer. Our findings demonstrated that liquiritin significantly suppressed cell proliferation and induced cell cycle arrest in a dose-dependent manner. In addition, liquiritin triggered apoptosis by inhibiting the phosphatidylinositol-4,5-bisphosphate 3-kinase/protein kinase B signaling pathway. Liquiritin also reduced mitochondrial membrane potential, leading to mitochondrial dysfunction and promoting excessive reactive oxygen species (ROS) production by suppressing the EGFR/MAPK8 signaling pathway. Furthermore, liquiritin treatment resulted in a notable decrease in tumor size in breast cancer models through inhibiting cell proliferation and promoting apoptosis. In conclusion, liquiritin serves as an effective tumor suppressor, suppressing the proliferation and cell cycle progression of breast cancer cells, while inducing apoptosis by regulating mitochondrial function and ROS generation via the EGFR/MAPK8 signaling pathway.

Effects of AKT Inhibitors for PIK3CA/AKT1/PTEN-Altered Advanced or Metastatic Breast Cancer: A Meta-Analysis of Randomized Clinical Trials

PURPOSE

We aimed to answer the following question: How effective is the addition of AKT inhibitors to the treatment of advanced or metastatic breast cancer?

METHODS

We searched PubMed, Embase and Cochrane for randomized controlled trials (RCTs) that investigated AKT inhibitors for advanced or metastatic BC. We computed hazard-ratios (HRs) for binary endpoints.

RESULTS

A total of 5 RCTs were included in the meta-analysis, comprising 1,334 patients with BC. The use of AKT inhibitors demonstrated a significant improvement in OS (HR 0.70; 95% CI, 0.58-0.85; P < .001) and PFS (HR 0.6797; 95% CI, 0.5499-0.8403; P < .001) in the overall population. Within the PIK3CA/AKT1/PTEN-altered subgroup (n = 645), the OS rate also significantly favored AKT inhibitors over the control group (HR 0.62; 95% CI, 0.42-0.92; P = .019), as well as PFS (HR 0.5224; 95% CI, 0.3366-0.8105; P = .004).

CONCLUSIONS

Our findings suggest that the incorporation of AKT inhibitors holds promise for treating patients with advanced or metastatic PIK3CA/AKT1/PTEN-altered BC.

Network Pharmacology, Molecular Docking, and Molecular Dynamics Simulation Revealed the Molecular Targets and Potential Mechanism of Nauclea Latifolia in the Treatment of Breast Cancer

Breast cancer (BRCA) incidence is increasing, posing a significant public health challenge and necessitating effective treatment solutions. Nauclea latifolia (N. latifolia) has shown anticancer activity against multidrug-resistant BRCA cells, though its mechanism of action remains unclear. We used online databases Swiss Target Prediction and GeneCards to identify therapeutic targets for BRCA and active compounds in N. latifolia. Protein-protein interaction (PPI) network was constructed using the STRING database and Cytoscape. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed using the DAVID database. Molecular docking, gene expression, and survival analyses of core targets were conducted using Autodock 4.0 and GEPIA2 database. We identified 141 intersecting targets for BRCA and N. latifolia compounds, with key targets including ALB, AKT1, ESR1, STAT3, EGFR, SRC, PTGS2, GSK3B, MMP9, and PPAR1. These targets are involved in cell proliferation and death through pathways such as the PI3 K-Akt signaling system, metabolic pathways, cancer pathways, and proteoglycans in cancer. Gene expression and survival analysis indicated these targets as potential markers for BRCA treatment prognosis. This study provides insights into the mechanism of action of N. latifolia against BRCA cells and gives a basis to clinicians for future drug development.

Knockout of histone deacetylase 8 gene in breast cancer cells may alter the expression pattern of the signaling molecules

PURPOSE

Breast cancer (BC) is the most common cancer diagnosed in the world and it is also the main leading cause of cancer deaths in women. Change in epigenetic mechanisms promotes BC initiation and progression. Histone deacetylase 8 (HDAC8) was found to act as a potential oncogene in different malignancies. For better understanding of the HDAC8 function in BC development, we investigated the effect of HDAC8 deletion on the expression of genes involved in signaling pathways.

MATERIALS AND METHODS

In this study, CRISPR technology was used to knockout the HDAC8 gene in MDA-MB-468, MDA-MB-231 and MCF-7 ​cell lines. For this purpose, two gRNAs were designed and cloned into the PX459 vector. The gRNA-containing vectors were transfected into the BC cell lines and then the effect of this deletion on the expression of genes involved in signaling pathway was determined using quantitative real-time PCR (qRT-PCR).

RESULTS

Analysis of qRT-PCR results showed a reduction in the expression of studied genes in BC cell lines after deletion of the HDAC8 gene compared to untreated controls. Although this decline was not significant for FGF2 and FGFR1 genes, however the mTOR, IGF1R, INSR, VEGFA and VEGFR2 genes showed statistically significant reduction in the studied BC cell lines. In addition, the down-regulation of PDGFC and PDGFRA genes were only significant in the TNBC cell lines.

CONCLUSION

Overall, our study showed that HDAC8 can exert its oncogenic effects by altering the expression level of molecules involved in some signaling pathways, and inhibiting HDAC8 can revert these effects.

Targeting STAT3 for Cancer Therapy: Focusing on Y705, S727, or Dual Inhibition?

BACKGROUND/OBJECTIVES

Signal Transducer and Activator of Transcription 3 (STAT3) is a transcription factor that is strongly implicated in various cancers. In its canonical signaling pathway, Janus kinases (JAKs) phosphorylate STAT3 at the Y705 residue in response to cytokines or growth factors, with pY705 serving as a key marker of STAT3 oncogenic activity. Elevated pY705 levels correlate with poor prognosis, and numerous small-molecule inhibitors have been developed to block this phosphorylation site. More recently, phosphorylation at the S727 residue (pS727) has emerged as a critical contributor to STAT3-mediated oncogenesis, particularly due to its role in mitochondrial translocation. Evidence suggests that pS727 may even surpass pY705 in driving oncogenic activity. These findings prompt an important question: Which residue should be prioritized for effective STAT3 inhibition in cancer therapy?

METHODS

This review compiles and critically analyzes the current literature on STAT3 inhibitors targeting pY705 and/or pS727, evaluating their therapeutic efficacy in vitro, in vivo, and in clinical trials. We assess the unique effects of targeting each residue on downstream signaling, toxicity, and clinical outcomes.

RESULTS

Our analysis indicates that inhibitors targeting both pY705 and pS727 achieve the greatest therapeutic effectiveness. However, pS727 targeting is associated with higher toxicity risks.

CONCLUSIONS

Comprehensive evaluation of STAT3 inhibitors underscores the importance of targeting pY705 for maximum therapeutic benefit. The analysis also shows that co-targeting pS727 may increase overall efficacy. However, pS727 inhibition should be approached with lower affinity to minimize toxicity and enhance the clinical feasibility of dual-targeting strategies.

Emerging Combinatorial Drug Delivery Strategies for Breast Cancer: A Comprehensive Review

Breast cancer remains the second most prevalent cancer among women in the United States. Despite advancements in surgical, radiological, and chemotherapeutic techniques, multidrug resistance continues to pose significant challenges in effective treatment. Combination chemotherapy has emerged as a promising approach to address these limitations, allowing multiple drugs to target malignancies via distinct mechanisms of action. Increasingly, the use of phytoconstituents alongside chemotherapeutic agents has shown promise in enhancing treatment outcomes. This combination therapy acts on key signaling pathways such as Hedgehog, Notch, Wnt/β- catenin, tyrosine kinases, and phosphatidylinositol 3-kinase (PI3K), which play critical roles in cellular proliferation, apoptosis, angiogenesis, differentiation, invasion, and metastasis. This review explores various signaling pathways involved in breast cancer progression, discusses conventional treatment methods like surgery, adjuvant radiotherapy, hormonal therapy, and chemotherapy, and highlights emerging nanocarrier-based drug delivery systems (DDS). Liposomes, dendrimers, exosomes, polymeric micelles, and nanoparticles (organic, inorganic, gold, magnetic, carbon-based, and quantum dots) are examined as innovative strategies for enhancing drug delivery efficacy. Furthermore, stimuli-responsive DDSs, including reactive oxygen species (ROS), enzyme-, and hypoxia- responsive systems, are presented as cutting-edge approaches to overcoming drug resistance. Special emphasis is placed on the co-delivery of chemotherapeutic agents and plant-based compounds, particularly in estrogen receptor-positive (ER+) breast cancer. This review aims to provide a comprehensive overview of novel combinatorial strategies and advanced nanocarriers for the effective and targeted treatment of breast cancer.

Anti-migratory Properties of Cryoprotective Isoliquiritigenin-zein Phosphatidylcholine Nanoparticles Prevent Triple-negative Breast Cancer through PI3K-mTOR and MMP2/9 Pathways

INTRODUCTION

Triple-negative breast cancer (TNBC), an aggressive type of breast cancer, remains difficult to treat. Isoliquiritigenin (ISL) is a bioactive compound that is insoluble in water and exhibits significant anti-TNBC activity.

METHODS

We previously prepared oral aqueous ISL@ZLH NPs; however, they were less stable in a freezing environment. Hence, the present study aimed to improve the stability of ISL@ZLH NPs using cryoprotectants that can withstand long storage times and are effective in TNBC treatment by creating an efficient oral drug delivery system. Freeze-dried ISL@ZLH NP powder was prepared by solvent evaporation, followed by the addition of trehalose and sucrose. The freeze-dried ISL@ZLH NP pow was optimized and characterized. The anti-TNBC efficacy and pharmacokinetics of the ISL@ZLH NP-pow were examined in plasma and organs, compared with those of aqueous ISL@ZLH NPs.

RESULT

The ideal particle size of the ISL@ZLH NP pow was 118 nm, which was not filtered out by the glomerulus and allowed the drug to be delivered to the lesions more effectively. Cellular uptake and biodistribution of the ISL@ZLH NP-pow in vivo and in vitro showed prolonged storage in the organs. In addition, cryopreserved ISL@ZLH NP-treated tumors showed significant anti- proliferative and anti-migratory effects through the downregulation of the PI3K-Akt-mToR and MMP2/9 signaling pathways.

CONCLUSION

These results suggest that oral ingestion of cryopreserved ISL@ZLH NP has the potential for long-term storage and can be employed as a clinical therapeutic approach to treat TNBC.

Insights into the Emerging Therapeutic Targets of Triple-negative Breast Cancer

Triple-negative Breast Cancer (TNBC), the most aggressive breast cancer subtype, is characterized by the non-appearance of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). Clinically, TNBC is marked by its low survival rate, poor therapeutic outcomes, high aggressiveness, and lack of targeted therapies. Over the past few decades, many clinical trials have been ongoing for targeted therapies in TNBC. Although some classes, such as Poly (ADP Ribose) Polymerase (PARP) inhibitors and immunotherapies, have shown positive therapeutic outcomes, however, clinical effects are not much satisfiable. Moreover, the development of drug resistance is the major pattern observed in many targeted monotherapies. The heterogeneity of TNBC might be the cause for limited clinical benefits. Hence,, there is a need for the potential identification of new therapeutic targets to address the above limitations. In this context, some novel targets that can address the above-mentioned concerns are emerging in the era of TNBC therapy, which include Hypoxia Inducible Factor (HIF-1α), Matrix Metalloproteinase 9 (MMP-9), Tumour Necrosis Factor-α (TNF-α), β-Adrenergic Receptor (β-AR), Voltage Gated Sodium Channels (VGSCs), and Cell Cycle Regulators. Currently, we summarize the ongoing clinical trials and discuss the novel therapeutic targets in the management of TNBC.

Metabolic Switch in Endocrine Resistant Estrogen Receptor Positive Breast Cancer

Purpose

The development of endocrine resistance remains a significant challenge in the clinical management of estrogen receptor-positive (ER+) breast cancer. Metabolic reprogramming is a prominent component of endocrine resistance and a potential therapeutic intervention point. However, a limited understanding of which metabolic changes are conserved across the heterogeneous landscape of ER+ breast cancer or how metabolic changes factor into ER DNA binding patterns hinder our ability to target metabolic adaptation as a treatment strategy. This study uses dimethyl fumarate (DMF) to restore tamoxifen (Tam) and fulvestrant (Fulv) sensitivity in endocrine-resistant cell lines and investigates how metabolic changes influence ER DNA-binding patterns.

Experimental Design

To address the challenge of metabolic adaptation in anti-endocrine resistance, we generated Tam and Fulv resistance in six ER+ breast cancer (BC) cell lines, representing ductal (MCF7, T47D, ZR75-1, and UCD12), lobular (MDA-MB-134--VI), and HER2 amplified (BT474) BC molecular phenotypes. Metabolomic profiling, RNA sequencing, proteomics, and CUT&RUN assays were completed to characterize metabolic shifts, transcriptional and protein changes, and ER DNA-binding patterns in resistant cells. Dimethyl fumarate was assessed for its ability to reverse Tam and Fulv resistance, restore tricarboxylic acid cycle (TCA) cycle function, and restore parental cell (endocrine sensitive) ER DNA binding patterns.

Results

Tamoxifen-resistant (TamR) and fulvestrant-resistant (FulvR) cells exhibited disrupted TCA cycle activity, reduced glutathione levels, and altered nucleotide and amino acid metabolism. DMF treatment replenished TCA cycle intermediates and reversed resistance in both TamR and FulvR cells. DMF also increased mevalonate pathway enzyme expression in both TamR and FulvR cells, with TamR cells upregulating enzymes in the cholesterol synthesis phase and FulvR enhancing enzymes in the early part of the pathway. DMF restored ER DNA-binding patterns in TamR cells to resemble parental cells, re-sensitizing them to Tam. In FulvR cells, DMF reversed resistance by modulating ER-cofactor interactions but did not restore parental ER DNA-binding signatures.

Conclusions

Our findings provide new insights into how metabolic reprogramming affects ER DNA-binding activity in endocrine-resistant breast cancer. We demonstrate how altering metabolism can reprogram ER signaling and influence resistance mechanisms by targeting metabolic vulnerabilities, such as TCA cycle disruptions. Additionally, our data provide a comprehensive metabolomic, RNA-seq, and CUT&RUN data set relevant to tumor metabolic adaptation leading to acquired endocrine resistance in highly utilized ER+ breast cancer cell lines. This study improves our understanding of how metabolic states alter ER function in endocrine-resistant breast cancer.

Epidemiology, risk factors and mechanism of breast cancer and atrial fibrillation

Cancer and cardiovascular diseases are leading causes of death worldwide. Among them, breast cancer is one of the most common malignancies in women, while atrial fibrillation is one of the most extensively studied arrhythmias, with significant public health implications. As the global population ages and advancements in cancer treatments continue, the survival rates of breast cancer patients have significantly improved, leading to an increasing coexistence of breast cancer and atrial fibrillation. However, the mechanisms underlying this coexistence remain insufficiently studied, and there is no consensus on the optimal treatment strategies for these patients. This review consolidates existing research to systematically explore the epidemiological characteristics, risk factors, and pathophysiological mechanisms of both breast cancer and atrial fibrillation. It focuses on the unique signaling pathways associated with different molecular subtypes of breast cancer and their potential impact on the mechanisms of atrial fibrillation. Additionally, the relationship between atrial fibrillation treatment medications and breast cancer is discussed. These insights not only provide essential evidence for the precise prevention and management of atrial fibrillation in breast cancer patients but also lay a solid theoretical foundation for interdisciplinary clinical management practices.

Direct comparison of an ultrasensitive real-time PCR assay with droplet digital PCR for the detection of PIK3CA hotspot mutations in primary tumors, plasma cell-free DNA and paired CTC-derived gDNAs

Introduction

Detection of PIK3CA mutations in primary tumors and liquid biopsy samples is of increasing importance for treatment decisions and therapy resistance in many types of cancer. The aim of the present study was to directly compare the efficacy of a relatively inexpensive ultrasensitive real-time PCR with the well-established and highly sensitive technology of ddPCR for the detection of the three most common hotspot mutations of PIK3CA, in exons 9 and 20, that are all of clinical importance in various types of cancer.

Patients and methods

We analyzed 42 gDNAs from primary tumors (FFPEs), 29 plasma-cfDNA samples, and 29 paired CTC-derived gDNAs, all from patients with ER+ metastatic breast cancer, and plasma from 10 healthy donors. The same blood draws were used for CTC isolation using EpCAM beads for positive immunomagnetic enrichment. All FFPEs and plasma-cfDNA samples were analyzed in parallel for PIK3CA mutations by ultrasensitive real-time PCR assay and droplet digital PCR.

Results

In gDNAs from FFPEs, using ultrasensitive real-time PCR, the p.E545K mutation was detected in 22/42(52.4%), and the p.E542K and p.H1047R mutations were detected in 14/42(33.3%) and 16/42(38.1%), respectively. Using ddPCR, the p.E545K mutation was detected in 22/42(52.4%), p.E542K in 17/42(40.5%), and p.H1047R in 19/42(45.2%) samples, revealing a concordance between the two methodologies of 81%, 78.6% and 78.6% for each mutation respectively. In plasma-cfDNA, using ultrasensitive real-time PCR, the p.E545K mutation was detected in 11/29(38%) and both p.E542K and p.H1047R mutations in 2/29(6.9%).In the same plasma-cfDNA samples using ddPCR, p.E545K was detected in 1/29(3.5%), p.E542K in 2/29(6.9%), and p.H1047R in 3/29(10.5%) samples, revealing a concordance of 65.5%,100% and 93.1% for each mutation respectively. In paired CTC-derived gDNAs p.E545K was detected in 11/29(38%), p.E542K in 3/29(10.3%), and p.H1047R in 7/29(24.1%) samples.

Conclusions

This low-cost, high-throughput and ultrasensitive real-time PCR assay provides accurate and specific detection of PIK3CA hotspot mutations in liquid biopsy samples and gives similar results to ddPCR. This assay can be performed in labs where digital PCR instrumentation is not available. In CTC-derived gDNA and paired plasma-cfDNA, PIK3CA mutations detected were not identical, revealing that CTC and plasma-cfDNA give complementary information.

Practical treatment strategies and novel therapies in the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway in hormone receptor-positive/human epidermal growth factor receptor 2 (HER2)-negative (HR+/HER2-) advanced breast cancer

Mutations in the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway occur in 30%-40% of patients with advanced hormone receptor-positive/human epidermal growth factor receptor 2 (HER2)-negative (HR+/HER2-) breast cancer. For most patients, endocrine therapy with a cyclin-dependent kinase 4/6 (CDK4/6) inhibitor is the first-line treatment. Recent studies indicate that adding inavolisib, a PI3Kα inhibitor, to palbociclib/fulvestrant benefits patients with endocrine-resistant HR+/HER2- metastatic breast cancer with a PIK3CA mutation. Alpelisib and capivasertib are both US Food and Drug Administration (FDA) approved in combination with fulvestrant in patients with endocrine-resistant HR+/HER2-, PIK3CA-mutant metastatic breast cancer, both with activity in the post-CDK4/6 setting. Capivasertib added to fulvestrant is the first AKT inhibitor to show a significant progression-free survival benefit with a trend for overall survival benefit and the only approved option for patients with phosphate and tensin homolog (PTEN) or AKT alterations. Toxicity profiles of all agents necessitate careful patient selection. Several mutant-selective and pan-mutant-selective novel inhibitors are under investigation with the potential to improve tolerability and efficacy.

Inhibitors of the mTOR signaling pathway can play an important role in breast cancer immunopathogenesis

This study explores the critical role of inhibitors targeting the mammalian target of rapamycin (mTOR) signaling pathway in breast cancer research and treatment. The mTOR pathway, a central regulator of cellular processes, has been identified as a crucial factor in the development and progression of breast cancer. The essay explains the complex molecular mechanisms through which mTOR inhibitors, such as rapamycin and its analogs, exert their anticancer effects. These inhibitors can stop cell growth, proliferation, and survival in breast cancer cells by blocking critical signaling pathways within the mTOR pathway. Furthermore, the essay discusses the implications of using mTOR inhibitors as a comprehensive therapeutic strategy. It emphasizes the potential benefits of combining mTOR inhibitors with other treatment approaches to enhance the effectiveness of breast cancer treatment. The evolving landscape of breast cancer research underscores the significance of mTOR as a therapeutic target and highlights ongoing efforts to improve and optimize mTOR inhibitors for clinical use. In conclusion, the essay asserts that inhibitors of the mTOR signaling pathway offer a promising approach in the fight against breast cancer. These inhibitors provide a focused and effective intervention targeting specific dysregulations within the mTOR pathway. As research advances, the integration of mTOR inhibitors into customized combination therapies holds excellent potential for shaping a more effective and personalized approach to breast cancer treatment, ultimately leading to improved outcomes for individuals affected by this complex and diverse disease.

Scaffold Hopping Method for Design and Development of Potential Allosteric AKT Inhibitors

Targeting AKT is a practical strategy for cancer therapy in many cancer types. Targeted inhibitors of AKT are attractive solutions for inhibiting the interconnected signaling pathways, like PI3K/Akt/mTOR. Allosteric inhibitors are more desirable among different classes of AKT inhibitors as they could be more specific with fewer off-target proteins. In this study, a ligand/structure-based pipeline was developed to design new allosteric AKT inhibitors by employing the core hopping method. Triciribine, a traditional allosteric AKT inhibitor was used as the template, and the FDA-approved kinase inhibitors for cancer treatment were considered as the cores. The allosteric site in the crystal structure of AKT1 was used to screen the designed compounds. The results were further evaluated using molecular docking, ADME/T analysis, molecular dynamics (MD) simulation, and binding free energy calculations. The outcomes introduced 24 newly designed inhibitors, amongst which three compounds C6, C20, and C16 showed remarkable binding affinity to AKT1. While the docking scores for triciribine was around - 8.6 kcal/mol, the docking scores of these compounds were about - 11 to - 13 kcal/mol. The MD results indicated that designed compounds target the essential residues of the PH domain and kinase domain of AKT, such as Trp80, Thr211, Tyr272, Asp274, and Asp292. Scaffold hopping is a tremendous tool for designing novel anti-cancer agents by improving already known and potential drug compounds. The designed compounds are worth to be examined by experimental investigation in vitro and in vivo.

ResisenseNet hybrid neural network model for predicting drug sensitivity and repurposing in breast Cancer

Breast cancer remains a leading cause of mortality among women worldwide, with drug resistance driven by transcription factors and mutations posing significant challenges. To address this, we present ResisenseNet, a predictive model for drug sensitivity and resistance. ResisenseNet integrates transcription factor expression, genomic markers, drugs, and molecular descriptors, employing a hybrid architecture of 1D-CNN + LSTM and DNN to effectively learn long-range and temporal patterns from amino acid sequences and transcription factor data. The model demonstrated exceptional predictive accuracy, achieving a validation accuracy of 0.9794 and a loss value of 0.042. Comprehensive validation included comparisons with state-of-the-art models and ablation studies, confirming the robustness of the developed architecture. ResisenseNet has been applied to repurpose existing anticancer drugs across 14 different cancers, with a focus on breast cancer. Among the malignancies studied, drugs targeting Low-grade Glioma (LGG) and Lung Adenocarcinoma (LUAD) showed increased sensitivity to breast cancer as per ResisenseNet's assessment. Further evaluation of the predicted sensitive drugs revealed that 14 had no prior history of anticancer activity against breast cancer. These drugs target key signaling pathways involved in breast cancer, presenting novel therapeutic opportunities. ResisenseNet addresses drug resistance by filtering ineffective compounds and enhancing chemotherapy for breast cancer. In vitro studies on sensitive drugs provide valuable insights into breast cancer prognosis, contributing to improved treatment strategies.

Sacituzumab govitecan in triple-negative breast cancer: from bench to bedside, and back

Triple-negative breast cancer (TNBC) represents a major therapeutic challenge due to its heterogeneous and aggressive phenotype, and limited target-specific treatment options. The trophoblast cell surface antigen (Trop-2), a transmembrane glycoprotein overexpressed in various cancers, has emerged as a promising target for TNBC. Sacituzumab govitecan (SG), an antibody-drug conjugate (ADC) that targets Trop-2, has recently entered treatment algorithms for advanced and metastatic TNBC, independently from Trop-2 expression status, with manageable toxicity. Despite the impressive results, questions remain unsolved regarding its efficacy, safety profile, and Trop-2 biological role in cancer. Currently, Trop-2 cannot be designated as a predictive biomarker in SG treatment, albeit its expression correlates with disease outcome, yet its levels are not uniform across all TNBCs. Additionally, data regarding Trop-2 expression variations in primary and metastatic sites, and its interplay with other biomarkers are still ambiguous but mandatory in light of future applications of SG in other indications and settings. This poses the questions of a careful evaluation of the efficacy and toxicity profile of SG in such early stages of disease, and in personalized and combinatorial strategies. Research and clinical data are mandatory to address SG drawbacks and minimize its benefits, to realize its full potential as therapeutic agent in different epithelial tumors.

Navigating the complexity of PI3K/AKT pathway in HER-2 negative breast cancer: biomarkers and beyond

The results of the SOLAR-1 and CAPItello-291, highlight the benefit of the ɑ-selective phosphoinositide 3-Kinase Pathway inhibitor (PI3Ki) alpelisib and the AKT inhibitor (AKTi) capivasertib in patients with hormone receptor-positive (HR+)/Human Epidermal Growth Factor Receptor 2 (HER2)- negative metastatic breast cancer (mBC) that have PIK3CA/AKT1/PTEN tumour alterations. Although effective, these drugs are associated with significant toxicities, which often limit their use, particularly in frail patients. Following the recent incorporation of these agents into clinical practice, and with many others currently in development, significant challenges have emerged, particularly those regarding biomarkers for patient selection. This review will discuss biomarkers of response and their resistance to PI3K/AKT inhibitors (PI3K/AKTis) in HR+/HER- BC in early and advanced settings to ascertain which populations will most benefit from these drugs. Of the biomarkers that were analysed, such as PIK3CA, AKT, PTEN mutations, insulin levels, 18 F-FDG-PET/TC, only the PIK3CA-mutations (PIK3CA-mut) and the AKT pathway alterations seem to have a predictive value for treatments with alpelisib and capivasertib. However, due to the retrospective and exploratory nature of the study, the data did not provide conclusive results. In addition, the different methods used to detect PIK3CA/AKT1/PTEN alterations underline the fact that the optimal diagnostic companion has yet to be established. We have summarised the clinical data on the approved and discontinued agents targeting this pathway and have assessed the drugs development, successes, and failures. Finally, because of tumour heterogeneity, we emphasise the importance of reassessing the mutational status of PI3KCA in both metastatic tissue and blood at the time of disease progression to better tailor treatment for patients.

Breast Cancer Stem Cells and Tumor Heterogeneity: Characteristics and Therapeutic Strategies

Breast cancer is one of the most frequently detected malignancies worldwide. It is responsible for more than 15% of all death cases caused by cancer in women. Breast cancer is a heterogeneous disease representing various histological types, molecular characteristics, and clinical profiles. However, all breast cancers are organized in a hierarchy of heterogeneous cell populations, with a small proportion of cancer stem cells (breast cancer stem cells (BCSCs)) playing a putative role in cancer progression, and they are responsible for therapeutic failure. In different molecular subtypes of breast cancer, they present different characteristics, with specific marker profiles, prognoses, and treatments. Recent efforts have focused on tackling the Wnt, Notch, Hedgehog, PI3K/Akt/mTOR, and HER2 signaling pathways. Developing diagnostics and therapeutic strategies enables more efficient elimination of the tumor mass together with the stem cell population. Thus, the knowledge about appropriate therapeutic methods targeting both "normal" breast cancer cells and breast cancer stem cell subpopulations is crucial for success in cancer elimination.

Small Molecule Therapeutics in the Pipeline Targeting for Triple-Negative Breast Cancer: Origin, Challenges, Opportunities, and Mechanisms of Action

Triple-negative breast cancer (TNBC) cells are devoid of estrogen receptors (ERs), progesterone receptor (PRs), and human epidermal growth factor receptor 2 (HER2), and it (TNBC) counts for about 10-15% of all breast cancers. TNBC is highly invasive, having a faster growth rate and a higher risk of metastasis and recurrence. Still, chemotherapy is one of the widely used options for treating TNBC. This study reviewed the histological and molecular characterization of TNBC subtypes, signaling pathways that are aberrantly expressed, and small molecules targeting these pathways, as either single agents or in combination with other therapeutic agents like chemotherapeutics, immunotherapeutics, and antibody-drug conjugates; their mechanisms of action, challenges, and future perspectives were also reviewed. A detailed analytical review was carried out using the literature collected from the SciFinder, PubMed, ScienceDirect, Google Scholar, ACS, Springer, and Wiley databases. Several small molecule inhibitors were found to be therapeutics for treating TNBC. The mechanism of action and the different signaling pathways through which the small molecules exert their effects were studied, including clinical trials, if reported. These small molecule inhibitors include buparlisib, everolimus, vandetanib, apatinib, olaparib, salidroside, etc. Some of the signaling pathways involved in TNBC, including the VEGF, PARP, STAT3, MAPK, EGFR, P13K, and SRC pathways, were discussed. Due to the absence of these biomarkers, drug development for treating TNBC is challenging, with chemotherapy being the main therapeutic agent. However, chemotherapy is associated with chemoresistance and a high toxicity to healthy cells as side effects. Hence, there is a continuous demand for small-molecule inhibitors that specifically target several signaling pathways that are abnormally expressed in TNBC. We attempted to include all the recent developments in this field. Any omission is truly unintentional.

Effects of Garlic on Breast Tumor Cells with a Triple Negative Phenotype: Peculiar Subtype-Dependent Down-Modulation of Akt Signaling

Breast cancer includes tumor subgroups with morphological, molecular, and clinical differences. Intrinsic heterogeneity especially characterizes breast tumors with a triple negative phenotype, often leading to the failure of even the most advanced therapeutic strategies. To improve breast cancer treatment, the use of natural agents to integrate conventional therapies is the subject of ever-increasing attention. In this context, garlic (Allium sativum) shows anti-cancerous potential, interfering with the proliferation, motility, and malignant progression of both non-invasive and invasive breast tumor cells. As heterogeneity could be at the basis of variable effects, the main objective of our study was to evaluate the anti-tumoral activity of a garlic extract in breast cancer cells with a triple negative phenotype. Established triple negative breast cancer (TNBC) cell lines from patient-derived xenografts (PDXs) were used, revealing subtype-dependent effects on morphology, cell cycle, and invasive potential, correlated with the peculiar down-modulation of Akt signaling, a crucial regulator in solid tumors. Our results first demonstrate that the effects of garlic on TNBC breast cancer are not unique and suggest that only more precise knowledge of the mechanisms activated by this natural compound in each tumor will allow for the inclusion of garlic in personalized therapeutic approaches to breast cancer.

Circular RNA PRKCI (hsa_circ_0067934): a potential target in the pathogenesis of human malignancies

Circular RNAs (circRNAs) are a new type of endogenous non-coding RNA formed by a covalent closed loop. CircRNAs are characterized by specificity, universality, conservation, and stability. They are abundant in eukaryotic cells and have biological regulatory roles at various transcriptional and post-transcriptional levels. The upregulation of circPRKCI has been observed in a variety of tumors and is directly related to the clinicopathological characteristics of tumors and prognosis. More importantly, circPRKCI can participate in the tumorigenesis, progression, recurrence, and metastasis of various tumors through many functional mechanisms, including the activation of signaling pathways, such as the phosphatidylinositol-3-kinase (PI3K)/AKT pathway, and sponging of many microRNAs (miRNAs). This review summarizes the progress achieved in understanding the biological functions of circRNA PRKCI in various tumors. The goal is to inform the discovery of more functional mechanisms and new anticancer molecular targets.

Progression from ductal carcinoma in situ to invasive breast cancer: molecular features and clinical significance

Ductal carcinoma in situ (DCIS) represents pre-invasive breast carcinoma. In untreated cases, 25-60% DCIS progress to invasive ductal carcinoma (IDC). The challenge lies in distinguishing between non-progressive and progressive DCIS, often resulting in over- or under-treatment in many cases. With increasing screen-detected DCIS in these years, the nature of DCIS has aroused worldwide attention. A deeper understanding of the biological nature of DCIS and the molecular journey of the DCIS-IDC transition is crucial for more effective clinical management. Here, we reviewed the key signaling pathways in breast cancer that may contribute to DCIS initiation and progression. We also explored the molecular features of DCIS and IDC, shedding light on the progression of DCIS through both inherent changes within tumor cells and alterations in the tumor microenvironment. In addition, valuable research tools utilized in studying DCIS including preclinical models and newer advanced technologies such as single-cell sequencing, spatial transcriptomics and artificial intelligence, have been systematically summarized. Further, we thoroughly discussed the clinical advancements in DCIS and IDC, including prognostic biomarkers and clinical managements, with the aim of facilitating more personalized treatment strategies in the future. Research on DCIS has already yielded significant insights into breast carcinogenesis and will continue to pave the way for practical clinical applications.

The PI3K/AKT/mTOR signaling pathway in breast cancer: Review of clinical trials and latest advances

Breast cancer (BC) is the most commonly diagnosed cancer and the leading cause of cancer mortality in women. As the phosphatidylinositol 3-kinase (PI3K) signaling pathway is involved in a wide range of physiological functions of cells including growth, proliferation, motility, and angiogenesis, any alteration in this axis could induce oncogenic features; therefore, numerous preclinical and clinical studies assessed agents able to inhibit the components of this pathway in BC patients. To the best of our knowledge, this is the first study that analyzed all the registered clinical trials investigating safety and efficacy of the PI3K/AKT/mTOR axis inhibitors in BC. Of note, we found that the trends of PI3K inhibitors in recent years were superior as compared with the inhibitors of either AKT or mTOR. However, most of the trials entering phase III and IV used mTOR inhibitors (majorly Everolimus) followed by PI3K inhibitors (majorly Alpelisib) leading to the FDA approval of these drugs in the BC context. Despite favorable efficacies, our analysis shows that the majority of trials are utilizing PI3K pathway inhibitors in combination with hormone therapy and chemotherapy; implying monotherapy cannot yield huge clinical benefits, at least partly, due to the activation of compensatory mechanisms. To emphasize the beneficial effects of these inhibitors in combined-modal strategies, we also reviewed recent studies which investigated the conjugation of nanocarriers with PI3K inhibitors to reduce harmful toxicities, increase the local concentration, and improve their efficacies in the context of BC therapy.

Targeting triple negative breast cancer stem cells using nanocarriers

Breast cancer is a complex and heterogeneous disease, encompassing various subtypes characterized by distinct molecular features, clinical behaviors, and treatment responses. Categorization of subtypes is based on the presence or absence of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2), leading to subtypes such as luminal A, luminal B, HER2-positive, and triple-negative breast cancer (TNBC). TNBC, comprising around 20% of all breast cancers, lacks expression of ER, PR, and HER2 receptors, rendering it unresponsive to targeted therapies and presenting significant challenges in treatment. TNBC is associated with aggressive behavior, high rates of recurrence, and resistance to chemotherapy. Tumor initiation, progression, and treatment resistance in TNBC are attributed to breast cancer stem cells (BCSCs), which possess self-renewal, differentiation, and tumorigenic potential. Surface markers, self-renewal pathways (Notch, Wnt, Hedgehog signaling), apoptotic protein (Bcl-2), angiogenesis inhibition (VEGF inhibitors), and immune modulation (cytokines, immune checkpoint inhibitors) are among the key targets discussed in this review. However, targeting the BCSC subpopulation in TNBC presents challenges, including off-target effects, low solubility, and bioavailability of anti-BCSC agents. Nanoparticle-based therapies offer a promising approach to target various molecular pathways and cellular processes implicated in survival of BSCS in TNBC. In this review, we explore various nanocarrier-based approaches for targeting BCSCs in TNBC, aiming to overcome these challenges and improve treatment outcomes for TNBC patients. These nanoparticle-based therapeutic strategies hold promise for addressing the therapeutic gap in TNBC treatment by delivering targeted therapies to BCSCs while minimizing systemic toxicity and enhancing treatment efficacy.

Combination Treatment with EGFR Inhibitor and Doxorubicin Synergistically Inhibits Proliferation of MCF-7 Cells and MDA-MB-231 Triple-Negative Breast Cancer Cells In Vitro

The role of the epidermal growth factor receptor (EGFR) in tumor progression and survival is often underplayed. Its expression and/or dysregulation is associated with disease advancement and poor patient outcome as well as drug resistance in breast cancer. EGFR is often overexpressed in breast cancer and particularly triple-negative breast cancer (TNBC), which currently lacks molecular targets. We examined the synergistic potential of an EGFR inhibitor (EGFRi) in combination with doxorubicin (Dox) in estrogen-positive (ER+) MCF-7 and MDA-MB-231 TNBC cell lines. The exposure of MDA-MB-231 and MCF-7 to EGFRi produced an IC50s of 6.03 µM and 3.96 µM, respectively. Dox induced MDA-MB-231 (IC50 9.67 µM) and MCF-7 (IC50 1.4 µM) cytotoxicity. Combinations of EGFRi-Dox significantly reduced the IC50 in MCF-7 (0.46 µM) and MBA-MB 231 (0.01 µM). Synergistic drug interactions in both cell lines were confirmed using the Bliss independence model. Pro-apoptotic Caspase-3/7 activation occurred in MCF-7 at 0.1-10 µM of EGFRi and Dox single treatments, whilst 1 μM Dox yielded a more potent effect on MDA-MB-231. EGFRi and Dox individually and in combination downregulated the EGFR gene expression in MCF-7 and MDA-MB-231 (p < 0.001). This study demonstrates EGFRi's potential for eliciting synergistic interactions with Dox, causing enhanced growth inhibition, apoptosis induction, and downregulation of EGFR in both cell lines.

Neo-adjuvant therapies for ER positive/HER2 negative breast cancers: from chemotherapy to hormonal therapy, CDK inhibitors, and beyond

INTRODUCTION

Chemotherapy has been traditionally used as neo-adjuvant therapy in breast cancer for down-staging of locally advanced disease in all sub-types. In the adjuvant setting, genomic assays have shown that a significant proportion of ER positive/HER2 negative patients do not derive benefit from the addition of chemotherapy to adjuvant endocrine therapy. An interest in hormonal treatments as neo-adjuvant therapies in ER positive/HER2 negative cancers has been borne by their documented success in the adjuvant setting. Moreover, cytotoxic chemotherapy is less effective in ER positive/HER2 negative disease compared with other breast cancer subtypes in obtaining pathologic complete responses.

AREAS COVERED

Neo-adjuvant therapies for ER positive/HER2 negative breast cancers and associated biomarkers are reviewed, using a Medline survey. A focus of discussion is the prediction of patients that are unlikely to derive extra benefit from chemotherapy and have the highest probabilities of benefiting from hormonal and other targeted therapies.

EXPERT OPINION

Predictive biomarkers of response to neo-adjuvant chemotherapy and hormonal therapies are instrumental for selecting ER positive/HER2 negative breast cancer patients for each treatment. Chemotherapy remains the standard of care for many of those patients requiring neo-adjuvant treatment, but other neo-adjuvant therapies are increasingly used.

[How could physical activity decrease the risk of breast cancer development and recurrence?]

OBJECTIVES

Breast cancer is the most frequent and deadly cancer among women. In France, 50% of adults are currently overweight, mostly as a result of a sedentary lifestyle. Numerous studies have highlighted overweight, obesity and lack of physical activity as risk factors for the occurrence and prognosis of cancers, particularly breast cancer. The aim of this study was to understand the extent to which physical activity can improve this prognosis, and what the pathophysiology is.

METHODS

The Senology Commission of the Collège national des gynécologues et obstétriciens français (CNGOF) based its responses on an analysis of the international literature using a Preferred Reporting Items for Systematic review and Meta-Analyses (PRISMA) methodology conducted on the PubMed database between 1994 and 2023.

RESULTS

A total of 70 articles were selected, demonstrating the role of regular physical activity in reducing the risk of breast cancer occurrence and recurrence. This role in controlling carcinogenesis is mediated by metabolic factors such as leptin, adiponectin and insulin, sex hormones and inflammation. The signaling pathways deregulated by these molecules are known carcinogenic pathways which could be used as therapeutic targets adapted to this population, without replacing the essential hygienic-dietary recommendations.

CONCLUSION

Physical activity has a protective effect on breast cancer risk and prognosis. We must therefore continue to raise awareness in the general population and promote physical activity as a means of primary, secondary, and tertiary prevention.

MicroRNA-203a inhibits breast cancer progression through the PI3K/Akt and Wnt pathways

MicroRNA expression in breast cancer (BC) is explored both as a potential biomarker and for therapeutic purposes. Recent studies have revealed that miR-203a-3p is involved in BC, and importantly contributes to BC chemotherapy responses; however, the regulatory pathways of miR-203a in BC remain elusive. Hence, we aimed to investigate the miR-203a regulatory mechanisms and their potential functions in the progress of BC. To this end, the miR-203a potential involving pathways was predicted by databases analyzing its target genes. The relations between miR-203a, the phosphatidylinositol 3'-kinase (PI3K)-Akt, and Wnt signaling pathways were mechanistically investigated. Our results revealed that miR-203a inhibited the activation of the PI3K/Akt and Wnt pathways and reduced its downstream cell cycle signals, including Cyclin D1 and c-Myc. Moreover, the overexpression of miR-203a drastically arrested the cell cycle at subG1 and G1 phases, decreased the viability, proliferation, and migration, and increased apoptosis of BC cells. Therefore, miR-203a-3p may be considered a tumor suppressor factor and a potential biomarker or therapeutic target for BC.

RPN1 promotes the proliferation and invasion of breast cancer cells by activating the PI3K/AKT/mTOR signaling pathway

Ribophorin I (RPN1), a part of an N-oligosaccharyl-transferase complex, plays a vital role in the development of multiple cancers. However, its biological role in breast cancer has not been completely clarified. The RPN1 expression level was measured in breast cancer tissues and breast cancer cell lines (MCF7) using RT-qPCR. After down-regulating RPN1 expression by shRNA, the effects of RPN1 on the proliferation, migration and invasion of MCF7 cells were examined. Mechanistically, we assessed the effect of RPN1 on the PI3K/ AKT/mTOR signaling pathway. We found that RPN1 level was up-regulated in breast cancer tissues and cells compared with adjacent non-tumor tissues or MCF10A cells. RPN1 knockdown induced apoptosis and attenuated the proliferation, migration, and invasion of MCF7 cells. Moreover, RPN1 knockdown lowered the levels of p-PI3K/PI3K, p-AKT/AKT, and p-mTOR/mTOR, which were rescued by 740Y-P, a PI3K activator. 740Y-P also reversed the effects of RPN1 knockdown on apoptosis, proliferation, migration, and invasion in MCF7 cells. Taken together, RPN1 promotes the proliferation, migration, and invasion of breast cancer cells via the PI3K/AKT/mTOR signaling pathway.

Sunitinib in Patients With Breast Cancer With FGFR1 or FGFR2 Amplifications or Mutations: Results From the Targeted Agent and Profiling Utilization Registry Study

PURPOSE

The Targeted Agent and Profiling Utilization Registry Study is a phase II basket trial evaluating the antitumor activity of commercially available targeted agents in patients with advanced cancer and genomic alterations known to be drug targets. Results from cohorts of patients with metastatic breast cancer (BC) with FGFR1 and FGFR2 alterations treated with sunitinib are reported.

METHODS

Eligible patients had measurable disease, Eastern Cooperative Oncology Group performance status 0-2, adequate organ function, and no standard treatment options. Simon's two-stage design was used with a primary end point of disease control (DC), defined as objective response (OR) or stable disease of at least 16 weeks duration (SD16+) according to RECIST v1.1. Secondary end points included OR, progression-free survival, overall survival, duration of response, duration of stable disease, and safety.

RESULTS

Forty patients with BC with FGFR1 (N = 30; amplification only n = 26, mutation only n = 1, both n = 3) or FGFR2 (N = 10; amplification only n = 2, mutation only n = 6, both n = 2) alterations were enrolled. Three patients in the FGFR1 cohort were not evaluable for efficacy; all patients in the FGFR2 cohort were evaluable. For the FGFR1 cohort, two patients with partial response and four with SD16+ were observed for DC and OR rates of 27% (90% CI, 13 to 100) and 7% (95% CI, 1 to 24), respectively. The null hypothesis of 15% DC rate was not rejected (P = .169). No patients achieved DC in the FGFR2 cohort (P = 1.00). Thirteen of the 40 total patients across both cohorts had at least one grade 3-4 adverse event or serious adverse event at least possibly related to sunitinib.

CONCLUSION

Sunitinib did not meet prespecified criteria to declare a signal of antitumor activity in patients with BC with either FGFR1 or FGFR2 alterations. Other treatments and clinical trials should be considered for these patient populations.

Therapies for the Treatment of Advanced/Metastatic Estrogen Receptor-Positive Breast Cancer: Current Situation and Future Directions

The hormone receptor-positive (HR+) type is the most frequently identified subtype of breast cancer. HR+ breast cancer has a more positive prognosis when compared to other subtypes, such as human epidermal growth factor protein 2-positive disorder and triple-negative disease. The advancement in treatment outcomes for advanced HR+ breast cancer has been considerably elevated due to the discovery of cyclin-dependent kinase 4/6 inhibitors and their combination effects with endocrine therapy. However, despite the considerable effectiveness of tamoxifen, a selective estrogen receptor modulator (SERMs), and aromatase inhibitors (AI), the issue of treatment resistance still presents a significant challenge for HR+ breast cancer. As a result, there is a focus on exploring new therapeutic strategies such as targeted protein degradation and covalent inhibition for targeting ERα. This article discusses the latest progress in treatments like oral selective ER degraders (SERDs), complete estrogen receptor antagonists (CERANs), selective estrogen receptor covalent antagonists (SERCAs), proteolysis targeting chimera (PROTAC) degraders, and combinations of CDK4/6 inhibitors with endocrine therapy. The focus is specifically on those compounds that have transitioned into phases of clinical development.

Molecular mechanisms and therapeutic applications of huaier in breast cancer treatment

Breast cancer is one of the most common female malignant tumors today and represents a serious health risk for women. Although the survival rate and quality of life of patients with breast cancer are improving with the continuous development of medical technology, metastasis, recurrence, and drug resistance of breast cancer remain a significant problem. Huaier, a traditional Chinese medicine (TCM) fungus, is a type of Sophora embolism fungus growing on old Sophora stems. The polysaccharides of Trametes robiniophila Murr (PS-T) are the main active ingredient of Huaier. There is increasing evidence that Huaier has great potential in breast cancer treatment, and its anti-cancer mechanism may be related to a variety of biological activities, such as the inhibition of cell proliferation, metastasis, tumor angiogenesis, the promotion of cancer cell death, and regulation of tumor-specific immunity. There is growing evidence that Huaier may be effective in the clinical treatment of breast cancer. This review systematically summarizes the basic and clinical studies on the use of Huaier in the treatment of breast cancer, providing useful information to guide the clinical application of Huaier and future clinical studies.

An overview of the therapeutic strategies for neoplastic meningitis due to breast cancer: when and why?

INTRODUCTION

Neoplastic meningitis (NM), also known as leptomeningeal carcinomatosis, is characterized by the infiltration of tumor cells into the meninges, and poses a significant therapeutic challenge owing to its aggressive nature and limited treatment options. Breast cancer is a common cause of NM among solid tumors, further highlighting the urgent need to explore effective therapeutic strategies. This review aims to provide insights into the evolving landscape of NM therapy in breast cancer by collating existing research, evaluating current treatments, and identifying potential emerging therapeutic options.

AREAS COVERED

This review explores the clinical features, therapeutic strategies, recent advances, and challenges of managing NM in patients with breast cancer. Its management includes multimodal strategies, including systemic and intrathecal chemotherapy, radiation therapy, and supportive care. This review also emphasizes targeted drug options and optimal drug concentrations, and discusses emerging therapies. Additionally, it highlights the variability in treatment outcomes and the potential of combination regimens to effectively manage NM in breast cancer.

EXPERT OPINION

Challenges in treating NM include debates over clinical trial end points and the management of adverse effects. Drug resistance and low response rates are significant hurdles, particularly inHER2-negative breast cancer. The development of more precise and cost-effective medications with improved selectivity is crucial. Additionally, global efforts are needed for infrastructure development and cancer control considering the diverse nature of the disease.

Cryptolepine Analog Exhibits Antitumor Activity against Ehrlich Ascites Carcinoma Cells in Mice via Targeting Cell Growth, Oxidative Stress, and PTEN/Akt/mTOR Signaling Pathway

BACKGROUND

The efficacy of chemotherapy continues to be limited due to associated toxicity and chemoresistance. Thus, synthesizing and investigating novel agents for cancer treatment that could potentially eliminate such limitations is imperative.

OBJECTIVE

The current study aims to explore the anticancer potency of cryptolepine (CPE) analog on Ehrlich ascites carcinoma cells (EACs) in mice.

METHODS

The effect of a CPE analog on EAC cell viability and ascites volume, as well as malonaldehyde, total antioxidant capacity, and catalase, were estimated. The concentration of caspase-8 and mTOR in EACs was also measured, and the expression levels of PTEN and Akt were determined.

RESULTS

Results revealed that CPE analog exerts a cytotoxic effect on EAC cell viability and reduces the ascites volume. Moreover, this analog induces oxidative stress in EACs by increasing the level of malonaldehyde and decreasing the level of total antioxidant capacity and catalase activity. It also induces apoptosis by elevating the concentration of caspase-8 in EACs. Furthermore, it decreases the concentration of mTOR in EACs. Moreover, it upregulates the expression of PTEN and downregulates the expression of Akt in EACs.

CONCLUSION

Our findings showed the anticancer activity of CPE analog against EACs in mice mediated by regulation of the PTEN/Akt/mTOR signaling pathway.

Novel Pyrazino[2,3-b] Pyrazines as mTOR Kinase Inhibitors for Treating Cancer and other Diseases

This paper describes the synthesis of some heteroaryl compounds and compositions comprising an effective amount of one or more such compounds and methods for treating or preventing cancer, inflammatory conditions, immunological conditions, metabolic conditions and conditions treatable or preventable by inhibition of a kinase pathway, comprising administering an adequate amount of a heteroaryl compound to a patient in need thereof. These compounds are mTOR/PI3K/Akt pathway inhibitors.

Elucidation of the Role of the Epigenetic Regulatory Mechanisms of PI3K/Akt/mTOR Signaling Pathway in Human Malignancies

The PI3K/Akt/mTOR pathway modulates cell growth, proliferation, metabolism, and movement. Moreover, significant studies have shown that the genes involved in this pathway are frequently activated in human cancer. Observational and computational modeling of the PI3K/AKt/ mTOR pathway inhibitors has been explored in clinical trials. It has been observed that the effectiveness and safety evidence from clinical studies and various inhibitors of this route have been given FDA approval. In this review article, we focused on the processes behind the overactivation of PI3K/Akt/mTOR signaling in cancer and provided an overview of PI3K/Akt/mTOR inhibitors as either individual drugs or a combination of different doses of drugs for different types of cancer. Furthermore, the review discusses the biological function and activation of the PI3K/AKt/mTOR signaling and their role in the development of cancers. Additionally, we discussed the potential challenges and corresponding prediction biomarkers of response and resistance for PI3K/Akt/m- TOR inhibitor development. The article focuses on the most current breakthroughs in using the PI3K/Akt/mTOR pathway to target certain molecules.

LINC00969 inhibits proliferation with metastasis of breast cancer by regulating phosphorylation of PI3K/AKT and ILP2 expression through HOXD8

Background

Breast cancer (BC) is a malignancy that is inadequately treated and poses a significant global health threat to females. The aberrant expression of long noncoding RNAs (lncRNAs) acts as a complex with a precise regulatory role in BC progression. LINC00969 has been linked to pyroptotic cell death and resistance to gefitinib in lung cancer cells. However, the precise function and regulatory mechanisms of LINC00969 in BC remain largely unexplored.

Methods

Cell proliferation, migration, and invasion of BC cells were evaluated using CCK-8 and Transwell assays. Western blotting was employed to analyze the protein expression levels of HOXD8, ILP2, PI3K, t-AKT, and p-AKT.

Results

LINC00969 was drastically reduced in BC tissues LINC00969 overexpression markedly suppressed proliferation, migration, and invasion, and blocked PI3K and p-AKT protein expression in MCF-7 cells. Activation of the PI3K/AKT pathway reversed the suppressive effect of LINC0096 overexpression on the proliferation, migration, and invasion of MCF-7 cells. Moreover, LINC00969 overexpression enhanced HOXD8 and blocked ILP2 protein expression in MCF-7 cells. In contrast, activating the PI3K/AKT pathway had no effect on HOXD8 and blocked ILP2 protein expression in MCF-7 cells overexpressing LINC00969. HOXD8 knockdown enhanced ILP2, PI3K, and p-AKT protein expression, and the proliferation, migration, and invasion of MCF-7 cells co-transfected with si-HOXD8 and ov-LINC00969. LINC00969 regulated HOXD8 via binding to miR-425-5p.

Conclusion

LINC00969 inhibits the proliferation and metastasis of BC cells by regulating PI3K/AKT phosphorylation through HOXD8/ILP2.

Advancement in precision diagnosis and therapeutic for triple-negative breast cancer: Harnessing diagnostic potential of CRISPR-cas & engineered CAR T-cells mediated therapeutics

Cancer is characterized by uncontrolled cell growth, disrupted regulatory pathways, and the accumulation of genetic mutations. These mutations across different types of cancer lead to disruptions in signaling pathways and alterations in protein expression related to cellular growth and proliferation. This review highlights the AKT signaling cascade and the retinoblastoma protein (pRb) regulating cascade as promising for novel nanotheranostic interventions. Through synergizing state-of-the-art gene editing tools like the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas system with nanomaterials and targeting AKT, there is potential to enhance cancer diagnostics significantly. Furthermore, the integration of modified CAR-T cells into multifunctional nanodelivery systems offers a promising approach for targeted cancer inhibition, including the eradication of cancer stem cells (CSCs). Within the context of highly aggressive and metastatic Triple-negative Breast Cancer (TNBC), this review specifically focuses on devising innovative nanotheranostics. For both pre-clinical and post-clinical TNBC detection, the utilization of the CRISPR-Cas system, guided by RNA (gRNA) and coupled with a fluorescent reporter specifically designed to detect TNBC's mutated sequence, could be promising. Additionally, a cutting-edge approach involving the engineering of TNBC-specific iCAR and syn-Notch CAR T-cells, combined with the co-delivery of a hybrid polymeric nano-liposome encapsulating a conditionally replicative adenoviral vector (CRAdV) against CSCs, could present an intriguing intervention strategy. This review thus paves the way for exciting advancements in the field of nanotheranostics for the treatment of TNBC and beyond.

Recent advances in targeted strategies for triple-negative breast cancer

Triple-negative breast cancer (TNBC), a highly aggressive subtype of breast cancer, negatively expresses estrogen receptor, progesterone receptor, and the human epidermal growth factor receptor 2 (HER2). Although chemotherapy is the main form of treatment for patients with TNBC, the effectiveness of chemotherapy for TNBC is still limited. The search for more effective therapies is urgent. Multiple targeted therapeutic strategies have emerged according to the specific molecules and signaling pathways expressed in TNBC. These include PI3K/AKT/mTOR inhibitors, epidermal growth factor receptor inhibitors, Notch inhibitors, poly ADP-ribose polymerase inhibitors, and antibody-drug conjugates. Moreover, immune checkpoint inhibitors, for example, pembrolizumab, atezolizumab, and durvalumab, are widely explored in the clinic. We summarize recent advances in targeted therapy and immunotherapy in TNBC, with the aim of serving as a reference for the development of individualized treatment of patients with TNBC in the future.

Harnessing the value of TCTP in breast cancer treatment resistance: an opportunity for personalized therapy

Early identification of breast cancer (BC) patients at a high risk of progression may aid in therapeutic and prognostic aims. This is especially true for metastatic disease, which is responsible for most cancer-related deaths. Growing evidence indicates that the translationally controlled tumor protein (TCTP) may be a clinically relevant marker for identifying poorly differentiated aggressive BC tumors. TCTP is an intriguing protein with pleiotropic functions, which is involved in multiple signaling pathways. TCTP may also be involved in stress response, cell growth and proliferation-related processes, underlying its potential role in the initiation of metastatic growth. Thus, TCTP marks specific cancer cell sub-populations with pronounced stress adaptation, stem-like and immune-evasive properties. Therefore, we have shown that in vivo phospho-TCTP levels correlate with the response of BC cells to anti-HER2 agents. In this review, we discuss the clinical relevance of TCTP for personalized therapy, specific TCTP-targeting strategies, and currently available therapeutic agents. We propose TCTP as an actionable clinically relevant target that could potentially improve patient outcomes.

The role of immune checkpoint inhibition in triple negative breast cancer

INTRODUCTION

Immunotherapy has revolutionized cancer treatment, including TNBC, which has limited options of treatment and poor prognosis. ICIs studied in TNBC include pembrolizumab, nivolumab, atezolizumab, and durvalumab. Initial studies exploring ICI monotherapy demonstrated promising yet limited responses. Subsequent studies, KEYNOTE 522 and KEYNOTE 355, which combined ICI with chemotherapy, have resulted in the FDA approval of pembrolizumab in the early-stage and metastatic setting, respectively.

AREAS COVERED

This article provides a comprehensive review of the role of ICI in the treatment of TNBC. We reviewed the trials that have evaluated ICI monotherapy, dual therapy, ICI in combination with chemotherapy, targeted therapy, vaccines and radiation. Additionally, we reviewed potential biomarkers of response and immune-related adverse events (irAEs). A literature search was conducted via PubMed and ClinicalTrials.gov as of 5 June 2023.

EXPERT OPINION

Various approaches combining immunotherapy with chemotherapy, targeted therapy, vaccines and radiation have been assessed. Pembrolizumab remains the only ICI approved in both the early stage and mTNBC. The role of adjuvant pembrolizumab in those who achieved pCR after neoadjuvant therapy is being investigated. Combining ICI with PARP inhibitors and radiation shows promise. More research is needed in identifying predictors of response. Monitoring of irAEs remains crucial.

Therapeutic Potential of Tumor Metabolic Reprogramming in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, with clinical features of high metastatic potential, susceptibility to relapse, and poor prognosis. TNBC lacks the expression of the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). It is characterized by genomic and transcriptional heterogeneity and a tumor microenvironment (TME) with the presence of high levels of stromal tumor-infiltrating lymphocytes (TILs), immunogenicity, and an important immunosuppressive landscape. Recent evidence suggests that metabolic changes in the TME play a key role in molding tumor development by impacting the stromal and immune cell fractions, TME composition, and activation. Hence, a complex inter-talk between metabolic and TME signaling in TNBC exists, highlighting the possibility of uncovering and investigating novel therapeutic targets. A better understanding of the interaction between the TME and tumor cells, and the underlying molecular mechanisms of cell-cell communication signaling, may uncover additional targets for better therapeutic strategies in TNBC treatment. In this review, we aim to discuss the mechanisms in tumor metabolic reprogramming, linking these changes to potential targetable molecular mechanisms to generate new, physical science-inspired clinical translational insights for the cure of TNBC.