Combined inhibition of CDK4/6 and AKT is highly effective against the luminal androgen receptor (LAR) subtype of triple negative breast cancer.

Luminal Androgen Receptor (LAR) triple-negative breast cancers (TNBC) express androgen receptors (AR), exhibit high frequency of PIK3CA mutations and intact RB. Herein, we investigated combined blockade of the CDK4/6 and PI3K signaling with palbociclib, alpelisib, and capivasertib, which inhibit CDK4/6, PI3Kα, and AKT1-3, respectively. The combination of palbociclib/capivasertib, but not palbociclib/alpelisib, synergistically inhibited proliferation of MDA-MB-453 and MFM-223 LAR cells [synergy score 7.34 (p=5.81x10-11) and 4.78 (p=0.012), respectively]. The AR antagonist enzalutamide was inactive against MDA-MB-453, MFM-223, and CAL148 cells and did not enhance the efficacy of either combination. Palbociclib/capivasertib inhibited growth of LAR patient-derived xenografts more potently than palbociclib/alpelisib. Treatment of LAR cells with palbociclib suppressed phosphorylated-RB and resulted in adaptive phosphorylation/activation of S473 pAKT and AKT substrates GSK3ß, PRAS40, and FoxO3a. Capivasertib blocked palbociclib-induced phosphorylation of AKT substrates more potently than alpelisib. Treatment with PI3Kß inhibitors did not block phosphorylation of AKT substrates, suggesting that PI3Kß did not mediate the adaptive response to CDK4/6 inhibition. Phosphokinase arrays of MDA-MB-453 cells treated with palbociclib showed time-dependent upregulation of PDGFRß, GSK3ß, STAT3, and STAT6. RNA silencing of PDGFRß in palbociclib-treated MDA-MB-453 and MFM-223 cells blocked the upregulation of S473 pAKT, suggesting that the adaptive response to CDK4/6 blockade involves PDGFRß signaling. Finally, treatment with palbociclib and the PDGFR inhibitor CP637451 arrested growth of MDA-MB-453 and MFM-223 cells to the same degree as palbociclib/capivasertib. These findings support testing the combination of CDK4/6 and AKT inhibitors in patients with LAR TNBC, and further investigation of PDGFR antagonists in this breast cancer subtype.

Siglec-7 and Siglec-9 expression in primary triple negative and oestrogen receptor positive breast cancer and in vitro signalling.

Objectives: PD-1/PD-L1 immune checkpoint blockade can be an effective treatment for advanced breast cancer patients. However, patients with oestrogen receptor positive (ER+) tumors often display only low lymphocyte infiltration, while a large part of triple negative (TN) breast tumors does not generate an effective immunotherapy response. Therefore, new treatment strategies have to be developed. Here, we investigate Siglec-7 and Siglec-9 as novel ITIM-bearing inhibitory immune checkpoint receptors similar to PD-1, but expressed on a broader range of immune cells. Methods: We assessed Siglec-7 and Siglec-9 (ligand) expression in TN and ER+ breast cancer tumors and their breast cancer cell line-induced signalling. Results: We report that Siglec-7 and Siglec-9 are highly expressed in TN tumors, and to a low extent in ER+ tumors. Siglec-7 was observed on myeloid cells, T cells, and NK cells and Siglec-9 preferentially on myeloid cells. Expression of sialoglycans, including Siglec-7 and Siglec-9 ligands, was observed in both TN and ER+ breast cancer tissue sections. Expression levels of Siglec-7 and Siglec-9 ligands were higher on in vitro cultured TN cell lines than ER+ cell lines. Importantly, by applying chimeric Siglec-7 reporter cells, we showed the induction of Siglec-7 signalling by multiple TN cell lines, but only by one ER+ cell line. Moreover, Siglec-7 signalling is directly related to Siglec-7 ligand expression levels of breast cancer cell lines. Conclusion: These data imply that immunotherapy targeting Siglec receptors may be particularly interesting for TN breast cancer patients not responding to current treatment strategies with tumors displaying high immune cell infiltration.

A Prognostic Risk Signature of Two Autophagy-Related Genes for Predicting Triple-Negative Breast Cancer Outcomes.

Background: Triple-negative breast cancer (TNBC) is recognized as the most aggressive molecular subtype of breast cancer. Recent studies have highlighted the complex role of autophagy in the pathogenesis of TNBC. Methods: In this study, we evaluated 18,330 genes, including 1111 autophagy-related genes, (ARGs), across 579 TNBC samples from online databases. Differentially expressed ARGs in TNBC were identified using high-throughput RNA-seq data from the Cancer Genome Atlas (TCGA). Prognostic factors were examined through Cox regression and multivariate Cox analyses, with predictive efficacy assessed using receiver operating characteristic (ROC) curves. A nomogram integrating the risk signature with clinicopathological factors, such as TNM stage, was developed. Immunohistochemical analysis of clinical samples was also conducted. Results: EIF4EBP1 and NPAS3 were significantly correlated with prognostic outcomes in patients with TNBC. Multivariate Cox regression analysis demonstrated that the expression levels of these two genes were accurate predictors of disease progression in TNBC samples from TCGA and the GSE31519 dataset. The efficacy of this predictive model was validated using ROC curve analysis and calibration plots, confirming its ability to accurately estimate the 1-, 2-, and 3-year survival rates for individuals with TNBC. Additionally, EIF4EBP1 and NPAS3 expression influenced drug sensitivity in TNBC cell lines, with notably lower NPAS3 expression in TNBC tissues, particularly in Stage III cases. This study is the first to report NPAS3 expression in patients with TNBC. Conclusion: The autophagy-related genes EIF4EBP1 and NPAS3 may serve as independent prognostic factors for individuals with TNBC.

The use of nanomaterials as drug delivery systems and anticancer agents in the treatment of triple-negative breast cancer: an updated review (year 2005 to date).

Triple-negative breast cancer (TNBC) is characterised by the lack or low expression of estrogen, progesterone, and human epidermal growth factor receptor 2 receptors. TNBC has a high recurrence rate, swiftly metastasizes, and has a high mortality rate. Subsequently, the increase in cases of TNBC has signaled the need for treatment strategies with improved drug delivery systems. New diagnostic approaches, chemical entities, formulations particular those in the nanometric range have emerged after extensive scientific research as alternative strategies for TNBC treatment. As compared to contemporary cancer therapy, nanoparticles offer peculiar tunable features namely small size, shape, electrical charge, magnetic and fluorescent properties. Specifically in targeted drug delivery, nanoparticles have been demonstrated to be highly efficient in encapsulating, functionalization, and conjugation. Presently, nanoparticles have ignited and transformed the approach in photodynamic therapy, bioimaging, use of theranostics and precision medicine delivery in breast cancer. Correspondingly, recent years have witnessed a drastic rise in literature pertaining to treatment of TNBC using nanomaterials. Subsequently, this manuscript aims to present a state-of-the-art of nanomaterials advance on TNBC treatment; the ubiquitous utility use of nanomaterials such as liposomes, dendrimers, solid lipid nanomaterials, gold nanomaterials and quantum dots as anticancer agents and drug delivery systems in TNBC.

Digital Whole Slide Image Analysis of Elevated Stromal Content and Extracellular Matrix Protein Expression Predicts Adverse Prognosis in Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) is a subtype of breast cancer with a poor prognosis and limited treatment options. This study evaluates the prognostic value of stromal markers in TNBC, focusing on the tumor-stroma ratio (TSR) and overall stroma ratio (OSR) in whole slide images (WSI), as well as the expression of type-I collagen, type-III collagen, and fibrillin-1 on tissue microarrays (TMAs), using both visual assessment and digital image analysis (DIA). A total of 101 female TNBC patients, primarily treated with surgery between 2005 and 2016, were included. We found that high visual OSR correlates with worse overall survival (OS), advanced pN categories, lower stromal tumor-infiltrating lymphocyte count (sTIL), lower mitotic index, and patient age (p < 0.05). TSR showed significant connections to the pN category and mitotic index (p < 0.01). High expression levels of type-I collagen (>45%), type-III collagen (>30%), and fibrillin-1 (>20%) were linked to significantly worse OS (p = 0.004, p = 0.013, and p = 0.005, respectively) and progression-free survival (PFS) (p = 0.028, p = 0.025, and p = 0.002, respectively), validated at the mRNA level. Our results highlight the importance of stromal characteristics in promoting tumor progression and metastasis and that targeting extracellular matrix (ECM) components may offer novel therapeutic strategies. Furthermore, DIA can be more accurate and objective in evaluating TSR, OSR, and immunodetected stromal markers than traditional visual examination.

The potential role of breast MRI in evaluation of triple-negative breast cancer and fibroadenoma of less than 3 cm.

Background: The majority of small-sized (<3 cm) triple-negative breast cancer (TNBC) exhibit smooth margins upon palpation and are often oval or rounded masses. Distinguishing these masses preoperatively from fibroadenomas (FAs) would be very meaningful for clinical practice. The aim of our study was to evaluate the magnetic resonance imaging (MRI) appearance of TNBC and differentiate it from FAs. Methods: In this retrospective single-center study, we included 37 patients with TNBCs and 36 patients with FAs who underwent breast MRI. We employed the χ2 test and t-test to compare the differences in morphological features, dynamic contrast-enhanced MRI (DCE-MRI) parameters, and apparent diffusion coefficient (ADC) values between the two groups. Additionally, we constructed non-parametric receiver operating characteristic (ROC) curves using ADC values, with pathological results serving as the gold standard. Results: A total of 37 TNBC lesions and 39 FA lesions were included in the final analysis. TNBCs exhibited more frequent irregular shape, irregular margins, peritumoral edema, fast enhancement in the initial phase, rim enhancement, and time-signal intensity curve (TIC) type III compared to FAs (all P<0.05). Conversely, low-signal segregation in T2-weighted imaging (T2WI) and TIC type I were commonly found in FAs. The mean ADC value of TNBCs was significantly lower than that of FAs [(1.104±0.13)×10-3 vs. (1.613±0.16)×10-3 mm2/s, P<0.05]. The cutoff ADC for differentiating TNBCs from FAs was 1.239×10-3 mm2/s, yielding an area under the curve (AUC) of 0.997, a sensitivity of 94.6%, and a specificity of 100%. Conclusions: The morphological presentation of MRI, internal enhancement features of the mass, TIC curves, and ADC values provide valuable differential diagnostic information for TNBC and FA masses with a maximum diameter of less than 3 cm.

Comparison of the effectiveness of neoadjuvant chemotherapy and adjuvant chemotherapy for improving prognosis in triple-negative breast cancer patients.

OBJECTIVE: To compare the effectiveness of surgery combined with neoadjuvant chemotherapy and radiotherapy (SNCR) versus surgery combined with adjuvant chemotherapy and radiotherapy (SACR) in improving the prognosis of triple-negative breast cancer (TNBC) patients. METHODS: Clinical data from 112 TNBC patients treated between January 2014 and February 2019 were retrospectively collected. Data included clinical characteristics and 5-year disease-free survival (DFS). Kaplan-Meier (K-M) survival curves were used to analyze the associations of various factors with DFS. Lasso-Cox regression was used to screen significant variables identified by K-M survival analysis. Multivariate Cox regression was used to determine independent prognostic factors affecting DFS. RESULTS: K-M survival analysis showed that treatment regimen (P=0.012), TNM (tumor, node, metastasis) staging (P=0.049), N staging (P=0.015), P53 (P=0.015), KI-67 (P=0.002), neutrophil-to-lymphocyte ratio (NLR) (P<0.001), platelet-to-lymphocyte ratio (PLR) (P<0.001), and cancer antigen 153 (CA153) (P<0.001) were associated with DFS in TNBC patients. Lasso-Cox regression analysis identified treatment regimen, TNM stage, P53, KI-67, NLR, PLR, and CA153 as features related to DFS when λ=0.053741 (1se). Multivariate Cox regression analysis revealed that treatment regimen (P<0.001, 95% CI: 2.309-14.396, HR=5.765), P53 (P=0.010, 95% CI: 1.315-7.864, HR=3.216), and NLR (P=0.001, 95% CI: 2.098-14.553, HR=5.525) were independent prognostic factors affecting DFS. A nomogram model was constructed, and time-dependent receiver operating characteristic (ROC) curve analysis showed that the model's areas under the curve (AUC) for predicting 1-, 3-, and 5-year DFS were 0.928, 0.816, and 0.665, respectively. CONCLUSION: The SNCR regimen significantly improves DFS in patients with stage IIb to IIIa TNBC compared to the traditional SACR regimen.

Dissection of triple-negative breast cancer microenvironment and identification of potential therapeutic drugs using single-cell RNA sequencing analysis.

Breast cancer remains a leading cause of mortality in women worldwide. Triple-negative breast cancer (TNBC) is a particularly aggressive subtype characterized by rapid progression, poor prognosis, and lack of clear therapeutic targets. In the clinic, delineation of tumor heterogeneity and development of effective drugs continue to pose considerable challenges. Within the scope of our study, high heterogeneity inherent to breast cancer was uncovered based on the landscape constructed from both tumor and healthy breast tissue samples. Notably, TNBC exhibited significant specificity regarding cell proliferation, differentiation, and disease progression. Significant associations between tumor grade, prognosis, and TNBC oncogenes were established via pseudotime trajectory analysis. Consequently, we further performed comprehensive characterization of the TNBC microenvironment. A crucial epithelial subcluster, E8, was identified as highly malignant and strongly associated with tumor cell proliferation in TNBC. Additionally, epithelial-mesenchymal transition (EMT)-associated fibroblast and M2 macrophage subclusters exerted an influence on E8 through cellular interactions, contributing to tumor growth. Characteristic genes in these three cluster cells could therefore serve as potential therapeutic targets for TNBC. The collective findings provided valuable insights that assisted in the screening of a series of therapeutic drugs, such as pelitinib. We further confirmed the anti-cancer effect of pelitinib in an orthotopic 4T1 tumor-bearing mouse model. Overall, our study sheds light on the unique characteristics of TNBC at single-cell resolution and the crucial cell types associated with tumor cell proliferation that may serve as potent tools in the development of effective anti-cancer drugs.

VMA21: unveiling a novel oncogene that facilitates immune evasion in triple-negative breast cancer through TCIRG1 protein stability regulation.

BACKGROUND: VMA21 has been shown to be dysregulated in a number of cancers. However, no study has yet explored whether VMA21 is involved in the regulation of triple-negative breast cancer (TNBC), especially from the level of immune escape. METHODS: The Gene Expression Omnibus (GEO) database was accessed to obtain the microarray dataset identified as GSE38959, which was then subjected to an analysis aimed at identifying genes that are differentially expressed (DEGs). The researchers examined the expression of VMA21 in TNBC cell lines. After knockdown of VMA21 in TNBC cells, cell proliferation, invasion, and migration were assessed by clone formation, cell scratch, and Transwell assay, respectively. The effect of VMA21 on immune cell function was explored by cell co-culture method, which was used to assess how TNBC cells with suppressed VMA21 expression affected CD8+ T cytotoxic potential and cytokine secretion. The effect of VMA21 on TCIRG1 protein stability and ubiquitination was assessed using immunoprecipitation. The effects of VMA21 knockdown on tumor xenograft growth and CD8+ T cell immune infiltration in mice were further evaluated. RESULTS: VMA21 expression is significantly elevated across various cell lines of TNBC. Furthermore, the perturbation of VMA21 notably suppresses key cell viability parameters in TNBC cells, including their proliferation, invasiveness, and migratory abilities. The modulation of VMA21 in TNBC cells can lead to a substantial augmentation in CD8+ T cell effectiveness. VMA21 stabilizes TCIRG1 protein expression by inhibiting its ubiquitination degradation. Further, VMA21 is involved in regulating TNBC cell proliferation, invasion and immune escape by promoting TCIRG1 expression. CONCLUSIONS: VMA21 is able to regulate TCIRG1 protein stability by binding to TCIRG1 protein in the form of ubiquitination, which ultimately promotes the malignant behavior as well as immune escape of TNBC cells.

Cystine/cysteine metabolism regulates the progression and response to treatment of triple­negative breast cancer (Review).

Breast cancer is the most prevalent neoplasm affecting women globally, of which a notable proportion of cases are triple-negative breast cancer (TNBC). However, there are limited curative treatment options for patients with TNBC, despite advancements in the field. Amino acids and amino acid transporters serve vital roles in the regulation of tumor metabolism. Notably, cystine and cysteine can interconvert via a redox reaction, with cysteine exerting control on cell survival and growth and exogenous cystine serving a crucial role in the proliferation of numerous types of cancers. Breast cancer has been reported to disrupt the cystine/cysteine metabolism pathway, as cystine and cysteine transporters affect the development and growth of tumors. The present review aims to provide a comprehensive overview of the metabolic pathways involving cystine and cysteine in normal and TNBC cells. Furthermore, the roles of cystine and cysteine transporters in TNBC progression and metastasis and their potential as therapeutic targets for treatment of TNBC are evaluated.

Efficacy and safety of PARPis combined with an ICIs for advanced or metastatic triple-negative breast cancer: a single-arm meta-analysis.

Although the intervention for triple-negative breast cancer (TNBC) patients has improved and survival time has increased, the combination of immune checkpoint inhibitors(ICIs) and PARP inhibitors (Poly ADP-Ribose Polymerase inhibitors, PARPis) is still controversial. Previous studies revealed that the combined use of ICIs and PARPis led to increased antitumor activity. However, most of these combined regimens are nonrandomized controlled trials with small sample sizes. The purpose of this meta-analysis was to evaluate the efficacy and safety of ICIs combined with PARPis in patients with advanced or metastatic TNBC. The PubMed, Embase, Cochrane Library and Web of Science databases were systematically searched. The results including the objective remission rate (ORR), disease control rate (DCR), progression-free survival (PFS) and adverse events (AEs), were subjected to further analysis. Four studies involving 110 subjects were included in this meta-analysis. The combined ORR and DCR were 23.6% and 53.6%, respectively; while the ORR and DCR of BRCAmut patients were 38.1% and 71.4%, respectively. The median PFS of the patients was 4.29 months. As for safety, the most common AEs were nausea (49.0%), anemia (44.3%) and fatigue (40.6%). Most of them were grade 1 or 2, and the incidence of adverse events ≥ III was obviously low. Except for anemia, the incidence of AEs ≥ III was < 10%. This meta-analysis revealed that the combination of ICIs and PARPis has good efficacy and safety for advanced or metastatic TNBC patients.

Recent Advances in Immunotherapy for Breast Cancer: A Review.

Breast cancer is one of the most common malignant tumors in women in the world, and its incidence is increasing year by year, which seriously threatens the physical and mental health of women. Triple negative breast cancer (TNBC) is a special molecular type of breast cancer in which estrogen receptor, progesterone receptor and human epidermal growth factor receptor-2 are negative. Compared with other molecular types of breast cancer, triple-negative breast cancer (TNBC) has high aggressiveness and metastasis, high recurrence rate, lack of effective therapeutic targets, and usually poor clinical treatment effect. Chemotherapy was the main therapeutic means used in the past. With the advent of the immune era, immunotherapy has made a lot of progress in the treatment of triple-negative breast cancer (TNBC), bringing new therapeutic hope for the treatment of triple-negative breast cancer. This review combines the results of cutting-edge medical research, mainly summarizes the research progress of immunotherapy, and summarizes the main treatment methods of triple-negative breast cancer (TNBC) immunotherapy, including immune checkpoint inhibitors, tumor vaccines, adoptive immunotherapy and the application of traditional Chinese and western medicine. It provides a new idea for the treatment of triple negative breast cancer (TNBC).

Targeting DNA damage repair mechanism by using RAD50-silencing siRNA nanoparticles to enhance radiotherapy in triple negative breast cancer.

Radiotherapy (RT) is one of major therapeutic modalities in combating breast cancer. In RT, ionizing radiation is employed to induce DNA double-strand breaks (DSBs) as a primary mechanism that causes cancer cell death. However, the induced DNA damage can also trigger the activation of DNA repair mechanisms, reducing the efficacy of RT treatment. Given the pivotal role of RAD50 protein in the radiation-responsive DNA repair pathways involving DSBs, we developed a novel polymer-lipid based nanoparticle formulation containing RAD50-silencing RNA (RAD50-siRNA-NPs) and evaluated its effect on the RAD50 downregulation as well as cellular and tumoral responses to ionizing radiation using human triple-negative breast cancer as a model. The RAD50-siRNA-NPs successfully preserved the activity of the siRNA, facilitated its internalization by cancer cells via endocytosis, and enabled its lysosomal escape. The nanoparticles significantly reduced RAD50 expression, whereas RT alone strongly increased RAD50 levels at 24 h. Pretreatment with RAD50-siRNA-NPs sensitized the cancer cells to RT with ∼2-fold higher level of initial DNA DSBs as determined by a γH2AX biomarker and a 2.5-fold lower radiation dose to achieve 50 % colony reduction. Intratumoral administration of RAD50-siRNA-NPs led to a remarkable 53 % knockdown in RAD50. The pretreatment with RAD50-siRNA-NPs followed by RT resulted in approximately a 2-fold increase in DNA DSBs, a 4.5-fold increase in cancer cell apoptosis, and 2.5-fold increase in tumor growth inhibition compared to RT alone. The results of this work demonstrate that RAD50 silencing by RAD50-siRNA-NPs can disrupt RT-induced DNA damage repair mechanisms, thereby significantly enhancing the radiation sensitivity of TNBC MDA-MB-231 cells in vitro and in orthotopic tumors as measured by colony forming and tumor regrowth assays, respectively.

Low-pass whole genome sequencing of circulating tumor cells to evaluate chromosomal instability in triple-negative breast cancer.

Chromosomal Instability (CIN) is a common and evolving feature in breast cancer. Large-scale Transitions (LSTs), defined as chromosomal breakages leading to gains or losses of at least 10 Mb, have recently emerged as a metric of CIN due to their standardized definition across platforms. Herein, we report the feasibility of using low-pass Whole Genome Sequencing to assess LSTs, copy number alterations (CNAs) and their relationship in individual circulating tumor cells (CTCs) of triple-negative breast cancer (TNBC) patients. Initial assessment of LSTs in breast cancer cell lines consistently showed wide-ranging values (median 22, range 4-33, mean 21), indicating heterogeneous CIN. Subsequent analysis of CTCs revealed LST values (median 3, range 0-18, mean 5), particularly low during treatment, suggesting temporal changes in CIN levels. CNAs averaged 30 (range 5-49), with loss being predominant. As expected, CTCs with higher LSTs values exhibited increased CNAs. A CNA-based classifier of individual patient-derived CTCs, developed using machine learning, identified genes associated with both DNA proliferation and repair, such as RB1, MYC, and EXO1, as significant predictors of CIN. The model demonstrated a high predictive accuracy with an Area Under the Curve (AUC) of 0.89. Overall, these findings suggest that sequencing CTCs holds the potential to facilitate CIN evaluation and provide insights into its dynamic nature over time, with potential implications for monitoring TNBC progression through iterative assessments.

PCMT1 as a prognostic marker in breast cancer.

INTRODUCTION: Triple-negative breast cancer (TNBC) is one of the most aggressive cancers in women, therefore it is necessary to determine novel prognostic markers to estimate survival and advancement the treatment of the disease. Recently, PCMT1, a protein mediating TNBC immune infiltration, has gained attention as a potential therapeutic target. The aim of the study was to demonstrate the relationship between PCMT1 protein overexpression as a prognostic indicator for patients with TNBC cancer and patient survival. MATERIALS AND METHODS: The study included 64 samples collected from 64 TNBC patients. We used the ImageJ software with the IHC Profiler driver for image analysis. To improve the reliability of the results, we expanded the analysis by including The Cancer Genome Atlas cohort. RESULTS: We observed strong PCMT1 immunoreactivity in breast cancer samples and PCMT1 expression in TNBC was significantly higher than in the control group. Patients with high PCMT1 expression had a significantly lower overall survival rate (60.62% vs. 90.35%, respectively) than patients with low PCMT1 expression. In our study and TCGA groups, PCMT1 expression did not correlate with lymph node involvement and distant metastases but correlated with tumor stage. The results obtained in a larger TCGA group are consistent with those in our research group. Overexpression of PCMT1 was a prognostic marker of shorter survival in patients with TNBC. CONCLUSIONS: The overexpression of the PCMT1 protein in triple negative breast cancer significantly correlated with shorter overall survival. The confirmed association could be a potential prognostic biomarker for patients with TNBC.

Amorphous silica nanoparticles exhibit antitumor activity in triple-negative breast cancer cells.

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer that is mainly treated with cytotoxic chemotherapy. However, this treatment is not always effective, and an important percentage of patients develop recurrence. Nanomaterials are emerging as alternative treatment options for various diseases, including cancer. This work reports the synthesis, characterization, antitumor activity evaluation, and sub-acute toxicity studies of two formulations based on amorphous silica nanoparticles (SiNPs). They are functionalized with 3-aminopropyltriethoxisilane (Si@NH2) and folic acid (FA; Si@FA). The results show that SiNPs reduce the viability and migration of TNBC MDA-MB-231 and 4T1 cell lines and Si@FA do not affect the growth of the mammary nonmalignant HC11 cells. In addition, Si@FA induces reactive oxygen species (ROS) generation and displays antiproliferative and subsequently proapoptotic effects in MDA-MB-231 cells. Moreover, none of the SiNPs cause signs of sub-acute toxicity in mice when administered at 30 mg/kg over a month. In conclusion, these nanosystems display intrinsic antitumor activity without causing toxic in vivo effects, being a promising therapeutic alternative for TNBC.

JARID2 activation by NFYA promotes stemness of triple-negative breast cancer cells through the PI3K/AKT pathway.

BACKGROUND: This study aimed to investigate the role of Jumonji AT Rich Interacting Domain 2 (JARID2) in regulating triple-negative breast cancer (TNBC) stemness and its mechanism. RESEARCH DESIGN AND METHODS: Bioinformatics analysis examined JARID2 expression, prognosis, and transcription factors. Quantitative polymerase chain reaction, western blot, and immunohistochemistry detected expression. Dual luciferase reporter gene and chromatin immunoprecipitation assays verified binding. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and colony formation assay detected viability and proliferation. Sphere formation assay detected the sphere formation efficiency. Flow cytometry detected CD44+/CD24- -marked stem cells. A xenograft tumor model verified the effect of JARID2 in vivo. RESULTS: JARID2 and nuclear transcription factor Y subunit α (NFYA) were upregulated in TNBC tissues and positively correlated. Knockdown of JARID2 or NFYA inhibited cell stemness by inhibiting the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (PKB/AKT) signaling pathway. Enforced JARID2 expression rescued the suppressive effect of NFYA knockdown on the PI3K/AKT signaling pathway and cell stemness. Knockdown of JARID2 inhibited tumor growth and cell stemness in mice but was alleviated by concurrent overexpression of NFYA. CONCLUSIONS: NFYA promotes TNBC cell stemness by upregulating JARID2 expression and regulating the PI3K/AKT signaling pathway, suggesting JARID2 as a potential target for innovating drugs that target TNBC stem cells.

Short Communication: Novel Di- and Triselenoesters as Effective Therapeutic Agents Inhibiting Multidrug Resistance Proteins in Breast Cancer Cells.

Breast cancer has the highest incidence rate among all malignancies worldwide. Its high mortality is mainly related to the occurrence of multidrug resistance, which significantly limits therapeutic options. In this regard, there is an urgent need to develop compounds that would overcome this phenomenon. There are few reports in the literature that selenium compounds can modulate the activity of P-glycoprotein (MDR1). Therefore, we performed in silico studies and evaluated the effects of the novel selenoesters EDAG-1 and EDAG-8 on BCRP, MDR1, and MRP1 resistance proteins in MCF-7 and MDA-MB-231 breast cancer cells. The cytometric analysis showed that the tested compounds (especially EDAG-8) are inhibitors of BCRP, MDR1, and MRP1 efflux pumps (more potent than the reference compounds-novobiocin, verapamil, and MK-571). An in silico study correlates with these results, suggesting that the compound with the lowest binding energy to these transporters (EDAG-8) has a more favorable spatial structure affecting its anticancer activity, making it a promising candidate in the development of a novel anticancer agent for future breast cancer therapy.

Cytotoxic properties, glycolytic effects and high-resolution respirometry mitochondrial activities of Eriocephalus racemosus against MDA-MB 231 triple-negative breast cancer.

INTRODUCTION: Triple-negative breast cancer (TNBC) represents a significant global health crisis due to its resistance to conventional therapies and lack of specific molecular targets. This study explored the potential of Eriocephalus racemosus (E. racemosus) as an alternative treatment for TNBC. The cytotoxic properties and high-resolution respirometry mitochondrial activities of E. racemosus against the MDA-MB 231 TNBC cell line were evaluated. METHODS: Hexane solvent and bioactive fraction extractions of E. racemosus were performed, while mass spectrometry-based metabolite profiling was used to identify the phytochemical constituents of the extracts. The extracts were further tested against MDA-MB 231 TNBC cells to determine their cytotoxicity. The mode of cell death was determined using flow cytometry. The activities of caspases 3, 8, and 9 were assessed using a multiplex activity assay kit. Glycolytic activity and High-resolution respirometry measurements of mitochondrial function in the MDA-MB 231 cell line were conducted using the Seahorse XFp and Oroboros O2K. RESULTS: Metabolite profiling of E. racemosus plant crude extracts identified the presence of coumarins, flavonoids, sesquiterpenoids, triterpenoids, and unknown compounds. The extracts demonstrated promising cytotoxic activities, with a half maximal inhibitory concentration (IC50) of 12.84 µg/mL for the crude hexane extract and 15.49 µg/mL for the bioactive fraction. Further, the crude hexane and bioactive fraction extracts induced apoptosis in the MDA-MB-231 TNBC cells, like the reference drug cisplatin (17.44%, 17.26% and 20.25%, respectively) compared to untreated cells. Caspase 3 activities confirmed the induction of apoptosis in both cisplatin and the plant crude extracts, while caspase 8 and 9 activities confirmed the activation of both the intrinsic and extrinsic apoptosis pathways. Increased levels of glycolytic activity were observed in the hexane crude extract. High-resolution respiratory measurements showed elevated mitochondrial activities in all mitochondrial states except for complex-IV activity. CONCLUSION: These findings support further exploration of E. racemosus as a potential therapeutic agent for TNBC, offering a promising avenue for the development of targeted treatments with minimal adverse effects.

Role of flavonoids in inhibiting triple-negative breast cancer.

Increasing incidences of metastasis or recurrence (or both) in triple-negative breast cancer (TNBC) are a growing concern worldwide, as these events are intricately linked to higher mortality rates in patients with advanced breast cancer. Flavonoids possess several pharmaceutical advantages with multi-level, multi-target, and coordinated intervention abilities for treating TNBC, making them viable for preventing tumor growth and TNBC metastasis. This review focused on the primary mechanisms by which flavonoids from traditional Chinese medicine extracts inhibit TNBC, including apoptosis, blocking of cell cycle and movement, regulation of extracellular matrix degradation, promotion of anti-angiogenesis, inhibition of aerobic glycolysis, and improvement in tumor microenvironment. This review aims to improve the knowledge of flavonoids as a promising pharmacological intervention for patients with TNBC.