Advances in small-molecule drug discovery for triple-negative breast cancer

PD-1/PD-L1 immune checkpoint inhibitors in the treatment of unresectable locally advanced or metastatic triple negative breast cancer: a meta-analysis on their efficacy and safety

BACKGROUND

Triple negative breast cancer (TNBC) represents a particularly aggressive and clinically challenging subtype of breast cancer, characterized by its invasive nature and generally poor prognosis. Treatment options for unresectable TNBC are limited. In recent years, the advent of PD-1/PD-L1 immune checkpoint inhibitors has offered a promising new treatment option for unresectable TNBC. The role of PD-1/PD-L1 immune checkpoint inhibitors (ICIs) in unresectable TNBC management remains a subject of debate. This article aims to synthesize evidence from randomized controlled trials (RCTs) through a meta-analysis (MA) to provide a comprehensive evaluation of the efficacy and safety profile of ICIs in the treatment of unresectable TNBC.

METHOD

We searched PubMed, Embase, Cochrane library, Web of Science, and ClinicalTrials.gov for the eligible RCTs which compared the efficacy and safety of PD-1/PD-L1 ICIs and chemotherapy alone. The outcomes analyzed included overall survival (OS), progression-free survival (PFS), objective response rate (ORR) and treatment-related adverse effects (AEs).

RESULTS

This meta-analysis included 11 trials. Therapy with PD-L1 inhibitors was superior to chemotherapy in terms of OS in both the intention-to-treat (ITT) population and the PD-L1-positive population. (ITT: HR: = 0.90 [0.81, 0.99], P = 0.04, I2 = 48%; PD-L1 + : HR = 0.82 [0.70, 0.95], P = 0.01, I2 = 64%); In terms of PFS, treatment with PD-L1 inhibitors prolonged PFS in both the ITT and PD-L1-positive populations compared with chemotherapy (ITT: HR: = 0.85 [0.77, 0.93], P = 0.0006, I2 = 46%; PD-L1 + : HR = 0.72 [0.62, 0.83], P < 0.00001, I2 = 70%, Fig. 5); Compared with chemotherapy alone, treatment with PD-1 inhibitors prolonged OS in both the PD-L1-positive and ITT populations. (ITT: HR = 0.87 [0.78, 0.96], P = 0.007, I2 = 71%; CPS ≥ 1: HR = 0.81 [0.71, 0.92], P = 0.001, I2 = 39%); In terms of PFS, therapy with PD-1 inhibitors improved PFS in both the ITT population and the PD-L1-positive population compared with chemotherapy. (ITT: HR = 0.79 [0.70, 0.90], P = 0.0004, I2 = 0%; CPS ≥ 1: HR = 0.71 [0.61, 0.83], P < 0.0001, I2 = 0%; CPS ≥ 10: HR = 0.67 [0.53, 0.84], P = 0.0008, I2 = 0%).

CONCLUSION

Both PD-1 and PD-L1 inhibitors can offer survival benefits to TNBC patients, with the primary beneficiaries being those who are PD-L1-positive. However, immunotherapy can also lead to an increase in treatment-related adverse events. Therefore, it is essential to conduct a risk assessment for each patient before starting treatment to prevent the occurrence of serious adverse reactions.

TRIAL REGISTRATION

This systematic review study has been filed with PROSPERO (Registration number: CRD42024571775).

Enhanced drug delivery with nanocarriers: a comprehensive review of recent advances in breast cancer detection and treatment

Breast cancer (BC) remains a leading cause of morbidity and mortality among women worldwide, with triple-negative breast cancer (TNBC) posing significant treatment challenges due to its aggressive phenotype and resistance to conventional therapies. Recent advancements in nanocarrier technology offer promising solutions for enhancing drug delivery, improving bioavailability, and increasing drug accumulation at tumor sites through targeted approaches. This review delves into the latest innovations in BC detection and treatment, highlighting the role of nanocarriers like polymeric micelles, liposomes, and magnetic nanoparticles in overcoming the limitations of traditional therapies. Additionally, the manuscript discusses the integration of cutting-edge diagnostic tools, such as multiplex PCR-Nested Next-Generation Sequencing (mPCR-NGS) and blood-based biomarkers, which are revolutionizing early detection and molecular profiling of BC. The convergence of these technologies not only enhances therapeutic outcomes but also paves the way for personalized medicine in BC management. This comprehensive review underscores the potential of nanocarriers in transforming BC treatment and emphasizes the critical importance of early detection in improving patient prognosis.

An overview of 6-shogaol: new insights into its pharmacological properties and potential therapeutic activities

Ginger (Zingiber officinale Roscoe) has traditionally been used as a cooking spice and herbal medicine for treating nausea and vomiting. More recently, ginger was found to effectively reduce the risk of diseases such as gastroenteritis, migraine, gonarthritis, etc., due to its various bioactive compounds. 6-Shogaol, the pungent phenolic substance in ginger, is the most pharmacologically active among such compounds. The aim of the present study was to review the pharmacological characteristic of 6-shogaol, including the properties of anti-inflammatory, antioxidant and antitumour, and its corresponding molecular mechanism. With its multiple mechanisms, 6-shogaol is considered a beneficial natural compound, and therefore, this review will shed some light on the therapeutic role of 6-shogaol and provide a theoretical basis for the development and clinical application of 6-shogaol.

Bias-force guided simulations combined with experimental validations towards GPR17 modulators identification

Glioblastoma Multiforme (GBM) is known to be by far the most aggressive brain tumor to affect adults. The median survival rate of GBM patient's is < 15 months, while the GBM cells aggressively develop resistance to chemo- and radiotherapy with their self-renewal capacity which suggests the pressing need to develop novel preventative measures. We have recently proved that GPR17 -an orphan G protein-coupled receptor- is highly expressed on the GBM cell surface and it has a vital role to play in the disease progression. Despite the progress made on GBM downregulation, there still remain difficulties in developing a promising modulator for GPR17, till date. Here, we have performed robust virtual screening combined with biased-force pulling molecular dynamic (MD) simulations to predict high-affinity GPR17 modulators followed by experimental validation. Initially, the database containing 1379 FDA-approved drugs were screened against the orthosteric binding pocket of the GPR17. The external bias-potentials were then applied to the screened hits during the MD simulations which enabled to predict a spectrum of rupture peak force values that were used to select four approved drugs -ZINC000003792417 (Sacubitril), ZINC000014210457 (Victrelis), ZINC000001536109 (Pralatrexate) and ZINC000003925861 (Vorapaxar)- as top hits. The hits selected turns out to demonstrate unique dissociation pathways, interaction pattern, and change in polar network over time. Subsequently the selected hits with GPR17 were measured by inhibiting the forskolin-stimulated cAMP accumulation in GBM cell lines, LN229 and SNB19. The ex vivo validations shows that Sacubitril drug can act as a full agonist, while Vorapaxar functions as a partial agonist for GPR17. The pEC₅₀ of Sacubitril was identified as 4.841 and 4.661 for LN229 and SNB19, respectively. Small interference of the RNA (siRNA)- silenced the GPR17 to further validate the targeted binding of Sacubitril with GPR17. In the current investigation, we have identified new repurposable GPR17 specific drugs which are likely to increase the opportunity to treat orphan deadly diseases.

EPHA2 antisense RNA modulates EPHA2 mRNA levels in basal-like/triple-negative breast cancer cells

Ephrin type-A receptor 2 (EPHA2) is a receptor tyrosine kinase (RTK), whose over-expression has been observed in a variety of cancers, including breast cancer. EPHA2 expression may be causally related to tumorigenesis; therefore, it is important to understand how EPHA2 gene (EPHA2) expression is regulated. Here, we report that EPHA2 antisense RNA (EPHA2-AS), a natural antisense transcript, is an important modulator of EPHA2 mRNA levels. EPHA2-AS is a ∼1.8 kb long non-coding RNA (lncRNA) with a poly(A) tail that encodes two splice variants, EPHA2-AS1/2. They are constitutively expressed in a concordant manner with EPHA2 mRNA in human breast adenocarcinoma cell lines and in patient samples, with the highest levels detected in the triple-negative breast cancer (TNBC) subtype. The silencing of EPHA2-AS1/2 by a sense oligonucleotide or over-expression of an antisense oligoribonucleotide, which were both designed from the EPHA2 mRNA region (nt 2955-2974) targeted by AS1/2, showed that EPHA2-AS1/2 modulated EPHA2 mRNA levels by interacting with the specific AS1/2-complementary region in the mRNA. The EPHA2-AS1/2 did not prevent microRNAs from acting on the relevant microRNA response elements shared by EPHA2-AS1/2 and EPHA2 mRNA. Our studies demonstrate a crucial role played by EPHA2-AS1/2 in modulating EPHA2 mRNA levels, and hence production of EPHA2 protein, a key oncogenic RTK that contributes to the tumorigenesis of TNBC cells.

Mifepristone Derivative FZU-00,003 Suppresses Triple-negative Breast Cancer Cell Growth partially via miR-153-KLF5 axis

Triple-negative breast cancer (TNBC) is one of the most malignant breast cancers lacking targeted therapeutics currently. We recently reported that mifepristone (MIF), a drug regularly used for abortion, suppresses TNBC cell growth by inhibiting KLF5 expression via inducing miR-153. However, its anticancer efficacy is only modest at high dose. In order to enhance the anticancer activities, a focused compound library containing 17 compounds by altering the sensitive metabolic region of mifepristone has been designed and synthesized. We first tested the cell growth inhibitory effects of these compounds in TNBC cell lines. Among them, FZU-00,003 displayed the most potent efficiency. FZU-00,003 suppresses TNBC cell growth, cell cycle progression and induces apoptosis more effectively than MIF does. Consistently, FZU-00,003 induces miR-153 expression and suppressed KLF5 expression at much lower dosages than MIF does. Furthermore, FZU-00,003 inhibits tumor growth more potently than MIF does. Taken together, the MIF derivative, FZU-00,003 may serve as a better therapeutic compound for TNBC than MIF.

Structural Modifications on CORM-3 Lead to Enhanced Anti-angiogenic Properties Against Triple-negative Breast Cancer Cells

PURPOSE

Carbon monoxide-releasing molecules (CORMs) are a special class of organometallic complexes that have been reported to offer beneficial effects against different conditions including several subtypes of cancer. Especially for the aggressive and poorly treated triplenegative breast cancer (TNBC), early CORMs have been shown to diminish malignant angiogenesis and may be considered as an alternative approach. So, this study aimed at testing novel CORM molecules against angiogenesis in TNBC seeking potent drug candidates for new therapies.

METHODS

Based on previous studies, CORM-3 was chosen as the lead compound and a group of 15 new ruthenium-based CORMs was synthesized and subsequently evaluated in vitro for potential anti-angiogenic properties.

RESULTS

A similar anti-angiogenic behaviour to the lead complex was observed and a new CORM, complex 4, emerged as a promising agent from this study. Specifically, this complex offered better inhibition of the activation of VEGFR2 and other downstream proteins of vascular endothelial cells. Complex 4 also retained the ability of the parent molecule to reduce the upregulated VEGF expression from TNBC cells and inhibit endothelial cell migration and new vessel formation. The lack of significant cytotoxicity and the downregulating activity over the cytoprotective enzyme haem oxygenase-1 (HO-1) in cancer cells may also favour CORMs against this poorly treated subtype of breast cancer.

CONCLUSION

Since the anti-angiogenic approach is one of the few available targeted strategies against TNBC, both CORM-3 and the new complex 4 should be considered for further research as combination agents with existing anti-angiogenic drugs for more effective treatment of malignant angiogenesis in TNBC.

Repurposing old carbon monoxide-releasing molecules towards the anti-angiogenic therapy of triple-negative breast cancer

Triple-negative breast cancer (TNBC) is defined by the lack of expression of the oestrogen and progesterone receptors and HER-2. Recently, carbon monoxide (CO) was found to behave as an important endogenous signalling molecule and to suppress VEGF receptor-2 (VEGFR-2) and protein kinase B phosphorylation. Given that anti-angiogenic drugs exist as one of the few available targeted therapies against TNBC, the aim of this project was to study the effects of CO-releasing molecules (CORMs) on TNBC cell lines and the associated endothelial cells and characterise their anti-angiogenic properties that can be used for the reduction of cancer-driven angiogenesis. Four commercially available CORMs were screened for their cytotoxicity, their effects on cell metabolism, migration, VEGF expression, tube formation and VEGFR-2 activation. The most important result was the reduction in VEGF levels expressed by CORM-treated TNBC cells, along with the inhibition of phosphorylation of VEGFR2 and downstream proteins. The migration and tube formation ability of endothelial cells was also decreased by CORMs, justifying a potential re-purposing of old CORMs towards the anti-angiogenic therapy of TNBC. The additional favourable low cytotoxicity, reduction in the glycolysis levels and downregulation of haem oxygenase-1 in TNBC cells enhance the potential of CORMs against TNBC. In this study, CORM-2 remained the most effective CORM and we propose that CORM-2 may be pursued further as an additional agent in combination with existing anti-angiogenic therapies for a more successful targeting of malignant angiogenesis in TNBC.

Silence of α1-Antitrypsin Inhibits Migration and Proliferation of Triple Negative Breast Cancer Cells

BACKGROUND α1-antitrypsin (α1-AT) is highly expressed in many tumors. However, to the best of our knowledge, its relationship to triple negative breast cancer (TNBC) has not yet been studied. Thus, in this research we first explored the influence of α1-AT silencing on the abilities of migration and invasion, and then further study its molecular mechanism in TNBC cells. MATERIAL AND METHODS The viability of MDA-MB-231 cells were detected using cell counting kit-8 (CCK-8). The abilities of migration and invasion were examined by Transwell assay. The metastasis-related factors were tested respectively by quantitative real-time PCR (qRT-PCR) and western blot assays. RESULTS Our study results showed that α1-AT level in TNBC tissues was higher than non-triple negative breast cancer (n-TNBC) and adjacent normal breast tissues. The high expression of α1-AT was linked to type of cancer, tumor size, TNM stage and metastasis, but was not correlated with α1-AT expression and age. si-α1-AT suppressed the viability, migration, and invasion of cells. While si-α1-AT upregulated E-cadherin and the tissue inhibitor of metalloproteinases-2 (TIMP-2) levels, it downregulated metastasis associated 1 (MTA1), matrix metallopeptidase 2 (MMP2), phosphorylated-mammalian target of rapamycin (p-mTOR), phosphorylated-protein kinase B (p-Akt), and phosphorylated-phosphatidylinositol 3 kinase (p-PI3K) levels. We also found that the PI3K/Akt/mTOR pathway activator reversed the role of si-α1-AT in metastasis-related factors. CONCLUSIONS α1-AT was highly expressed in TNBC tissues, and its silencing suppressed the abilities of migration and invasion in TNBC cells and downregulated the PI3K/Akt/mTOR pathway. Thus, α1-AT may have a potential therapeutic effect on TNBC.

Recent developments and advances of FGFR as a potential target in cancer

FGFs and their receptors (FGFRs) are critical for many biologic processes, including angiogenesis, wound healing and tissue regeneration. Aberrations in FGFR signaling are common in cancer, making FGFRs a promising target in antitumor studies. To date, many FGFR inhibitors are being detected in clinical studies, and resistance to some inhibitors has emerged. Understanding the mechanisms of resistance is a fundamental step for further implementation of targeted therapies. In this review, we will describe the basic knowledge regarding FGF/FGFR signaling and categorize the clinical FGFR inhibitors. The mechanisms of resistance to FGFR inhibitors and corresponding strategies of overcoming drug resistance will also be discussed.

Discovery of novel mifepristone derivatives via suppressing KLF5 expression for the treatment of triple-negative breast cancer

Triple-negative breast cancer (TNBC) is one of the most malignant breast cancers currently with a lack of targeted therapeutic drugs. Accumulating evidence supports that KLF5 represents a novel therapeutic target for the treatment of basal TNBC. Our previous studies revealed that mifepristone is capable of suppressing TNBC cell proliferation and promoting cancer cell apoptosis by inhibiting KLF5 expression. Nevertheless, its anticancer efficacy is only modest with high dose. Moreover, its main metabolite N-desmethyl mifepristone with the removal of one methyl moiety results in a significant loss of antiproliferative activity, indicating an important pharmacophore domain around this methyl moiety. To improve the pharmacokinetic properties including metabolic stability and enhance the anticancer activities, a focused compound library by altering this sensitive metabolic region of mifepristone has been designed and synthesized for scaffold repurposing and structural optimization. Compound 17 (FZU-00,004) has been identified with an attractive anticancer profile against TNBC via suppressing KLF5 expression.

Sphingosylphosphorylcholine Induces Thrombospondin-1 Secretion in MCF10A Cells via ERK2

Sphingosylphosphorylcholine (SPC) is one of the bioactive phospholipids that has many cellular functions such as cell migration, adhesion, proliferation, angiogenesis, and Ca²⁺ signaling. Recent studies have reported that SPC induces invasion of breast cancer cells via matrix metalloproteinase-3 (MMP-3) secretion leading to WNT activation. Thrombospondin-1 (TSP-1) is a matricellular and calcium-binding protein that binds to a wide variety of integrin and non-integrin cell surface receptors. It regulates cell proliferation, migration, and apoptosis in inflammation, angiogenesis and neoplasia. TSP-1 promotes aggressive phenotype via epithelial mesenchymal transition (EMT). The relationship between SPC and TSP-1 is unclear. We found SPC induced EMT leading to mesenchymal morphology, decrease of E-cadherin expression and increases of N-cadherin and vimentin. SPC induced secretion of thrombospondin-1 (TSP-1) during SPC-induced EMT of various breast cancer cells. Gene silencing of TSP-1 suppressed SPC-induced EMT as well as migration and invasion of MCF10A cells. An extracellular signal-regulated kinase inhibitor, PD98059, significantly suppressed the secretion of TSP-1, expressions of N-cadherin and vimentin, and decrease of E-cadherin in MCF10A cells. ERK2 siRNA suppressed TSP-1 secretion and EMT. From online PROGgene V2, relapse free survival is low in patients having high TSP-1 expressed breast cancer. Taken together, we found that SPC induced EMT and TSP-1 secretion via ERK2 signaling pathway. These results suggests that SPC-induced TSP-1 might be a new target for suppression of metastasis of breast cancer cells.

Small-molecule RL71-triggered excessive autophagic cell death as a potential therapeutic strategy in triple-negative breast cancer

Triple-negative breast cancer (TNBC) has an aggressive phenotype and a poor prognosis owing to the high propensity for metastatic progression and the absence of specific targeted treatment. Here, we revealed that small-molecule RL71 targeting sarco/endoplasmic reticulum calcium-ATPase 2 (SERCA2) exhibited potent anti-cancer activity on all TNBC cells tested. Apart from apoptosis induction, RL71 triggered excessive autophagic cell death, the main contributor to RL71-induced TNBC cell death. RL71 augmented the release of Ca²⁺ from the endoplasmic reticulum (ER) into the cytosol by inhibiting SERCA2 activity. The disruption of calcium homeostasis induced ER stress, leading to apoptosis. More importantly, the elevated intracellular calcium signals induced autophagy through the activation of the CaMKK-AMPK-mTOR pathway and mitochondrial damage. In two TNBC xenograft mouse models, RL71 also displayed strong efficacy including the inhibition of tumor growth, the reduction of metastasis, as well as the prolongation of survival time. These findings suggest SERCA2 as a previous unknown target candidate for TNBC treatment and support the idea that autophagy inducers could be useful as new therapeutics in TNBC treatment.

Targeting EphA2 impairs cell cycle progression and growth of basal-like/triple-negative breast cancers

Basal-like/triple-negative breast cancers (TNBCs) are among the most aggressive forms of breast cancer, and disproportionally affects young premenopausal women and women of African descent. Patients with TNBC suffer a poor prognosis due in part to a lack of molecularly targeted therapies, which represents a critical barrier for effective treatment. Here, we identify EphA2 receptor tyrosine kinase as a clinically relevant target for TNBC. EphA2 expression is enriched in the basal-like molecular subtype in human breast cancers. Loss of EphA2 function in both human and genetically engineered mouse models of TNBC reduced tumor growth in culture and in vivo. Mechanistically, targeting EphA2 impaired cell cycle progression through S-phase via downregulation of c-Myc and stabilization of the cyclin-dependent kinase inhibitor p27/KIP1. A small molecule kinase inhibitor of EphA2 effectively suppressed tumor cell growth in vivo, including TNBC patient-derived xenografts. Thus, our data identify EphA2 as a novel molecular target for TNBC.