Puerarin Decreases the Expression of FUS-Dependent MAPK4 to Inhibit the Development of Triple-Negative Breast Cancer.

Puerarin has been reported to have anticancer properties; however, its mechanism in regulating triple-negative breast cancer (TNBC) remains unclear. Cell function was assessed using a cell counting kit-8 assay, 5-ethynyl-2'-deoxyuridine assay, flow cytometry, and transwell assay. Additionally, the glucose assay kit, lactate assay kit, and ADP/ATP ratio assay kit were used to analyze glucose metabolism. mRNA and protein expression levels were analyzed using qRT-PCR and western blotting assays, respectively. The relationship between FUS RNA binding protein (FUS) and mitogen-activated protein kinase 4 (MAPK4) was determined using an RNA immunoprecipitation assay. TNBC cell malignancy in vitro was validated using a xenograft mouse model assay. Puerarin treatment or MAPK4 knockdown effectively inhibited TNBC cell proliferation, invasion, and glucose metabolism, and induced cell apoptosis. Additionally, puerarin treatment downregulated MAPK4 and FUS expression. Conversely, MAPK4 overexpression attenuated the effects of puerarin in TNBC cells. FUS stabilized MAPK4 mRNA expression in TNBC cells. Furthermore, puerarin decreased MAPK4 expression by downregulating FUS in TNBC cells. Finally, puerarin inhibited tumor formation in vivo. Puerarin inhibited TNBC development by decreasing the expression of FUS-dependent MAPK4, indicating that puerarin may serve as a promising therapeutic agent to hind TNBC.

NAC1 promotes stemness and regulates myeloid-derived cell status in triple-negative breast cancer.

Triple negative breast cancer (TNBC) is a particularly lethal breast cancer (BC) subtype driven by cancer stem cells (CSCs) and an immunosuppressive microenvironment. Our study reveals that nucleus accumbens associated protein 1 (NAC1), a member of the BTB/POZ gene family, plays a crucial role in TNBC by maintaining tumor stemness and influencing myeloid-derived suppressor cells (MDSCs). High NAC1 expression correlates with worse TNBC prognosis. NAC1 knockdown reduced CSC markers and tumor cell proliferation, migration, and invasion. Additionally, NAC1 affects oncogenic pathways such as the CD44-JAK1-STAT3 axis and immunosuppressive signals (TGFß, IL-6). Intriguingly, the impact of NAC1 on tumor growth varies with the host immune status, showing diminished tumorigenicity in natural killer (NK) cell-competent mice but increased tumorigenicity in NK cell-deficient ones. This highlights the important role of the host immune system in TNBC progression. In addition, high NAC1 level in MDSCs also supports TNBC stemness. Together, this study implies NAC1 as a promising therapeutic target able to simultaneously eradicate CSCs and mitigate immune evasion.

[Biological characteristics of triple negative breast cancer with low expression of HER2].

Objective: To investigate the biological characteristics of triple negative breast cancer (TNBC) with low expression of HER2 (HER2-low). Methods: A total of 93 TNBC cases in Shanxi Cancer Hospital from 2017 to 2019 were collected and divided into HER2-negative and HER2-low groups according to HER2 expression status. The clinicopathological features and prognostic differences between the two groups were retrospectively analyzed and compared, and genetic detection of tumor tissues was performed to clarify somatic mutation status and differences between the two groups. Results: Ninety-three patients aged 26 to 86 years were enrolled, including 60 patients in the HER2-negative group and 33 patients in the HER2-low group. The distribution of HER2-low in luminal androgen receptor (LAR) subtype (14/23, 60.87%) and non-LAR subtype (19/70, 27.14%) was significantly different (P=0.005). There were no significant differences in age, pT stage, histological grade, infiltration mode, lymph node metastasis and survival analysis. The expression of HER2-low in the tumor was heterogeneous, including different proportions of weak, weak to moderate intensity, and incomplete to intact membrane staining. With the change of the proportion of HER2-positive cells, the different distribution of those cells in the total tumor cells was noted, including cluster, mosaic and scattered patterns. The concentration and quality of DNA extracted from 71 of the 93 samples met the requirements for making libraries, including 43 in the HER2-negative group and 28 in the HER2-low group. Genetic mutations were mainly missense mutations, single nucleotide mutations, and point mutations in which base C was replaced by base T. There was no significant difference in genes with mutation frequency>3 times between the two groups. CTNNB1 and FGFR3 genes were only mutated in HER2-low group; while ALK, CYP2D6 and FAT1 genes were only mutated in HER2-negative group. HER2-low group included 18 HER2 1+ cases and 10 HER2 2+ cases. Genes with mutation frequency>3 times between the two groups included PIK3CA, TP53, SLX4, ATM and BRCA1. The mutation frequency of PIK3CA in HER2 2+ was significantly higher than that in HER2 1+ group (P<0.05), and SLX4 gene was only mutated in HER2 1+ group. Conclusions: There are some differences of histological morphology and genetic variation between HER2-negative group and HER2-low group, and also differences in genetic variation between HER2 1+ and HER2 2+ in HER2-low group, which are helpful for more accurate stratification of TNBC and useful for finding the therapeutic target and precise treatment of HER2-low TNBC.

Nanodynamo quantifies subcellular RNA dynamics revealing extensive coupling between steps of the RNA life cycle.

The coordinated action of transcriptional and post-transcriptional machineries shapes gene expression programs at steady state and determines their concerted response to perturbations. We have developed Nanodynamo, an experimental and computational workflow for quantifying the kinetic rates of nuclear and cytoplasmic steps of the RNA life cycle. Nanodynamo is based on mathematical modelling following sequencing of native RNA from cellular fractions and polysomes. We have applied this workflow to triple-negative breast cancer cells, revealing widespread post-transcriptional RNA processing that is mutually exclusive with its co-transcriptional counterpart. We used Nanodynamo to unravel the coupling between transcription, processing, export, decay and translation machineries. We have identified a number of coupling interactions within and between the nucleus and cytoplasm that largely contribute to coordinating how cells respond to perturbations that affect gene expression programs. Nanodynamo will be instrumental in unravelling the determinants and regulatory processes involved in the coordination of gene expression responses.

TBC1 domain-containing proteins are frequently involved in triple-negative breast cancers in connection with the induction of a glycolytic phenotype.

Metabolic plasticity is a hallmark of cancer, and metabolic alterations represent a promising therapeutic target. Since cellular metabolism is controlled by membrane traffic at multiple levels, we investigated the involvement of TBC1 domain-containing proteins (TBC1Ds) in the regulation of cancer metabolism. These proteins are characterized by the presence of a RAB-GAP domain, the TBC1 domain, and typically function as attenuators of RABs, the master switches of membrane traffic. However, a number of TBC1Ds harbor mutations in their catalytic residues, predicting biological functions different from direct regulation of RAB activities. Herein, we report that several genes encoding for TBC1Ds are expressed at higher levels in triple-negative breast cancers (TNBC) vs. other subtypes of breast cancers (BC), and predict prognosis. Orthogonal transcriptomics/metabolomics analysis revealed that the expression of prognostic TBC1Ds correlates with elevated glycolytic metabolism in BC cell lines. In-depth investigations of the three top hits from the previous analyses (TBC1D31, TBC1D22B and TBC1D7) revealed that their elevated expression is causal in determining a glycolytic phenotype in TNBC cell lines. We further showed that the impact of TBC1D7 on glycolytic metabolism of BC cells is independent of its known participation in the TSC1/TSC2 complex and consequent downregulation of mTORC1 activity. Since TBC1D7 behaves as an independent prognostic biomarker in TNBC, it could be used to distinguish good prognosis patients who could be spared aggressive therapy from those with a poor prognosis who might benefit from anti-glycolytic targeted therapies. Together, our results highlight how TBC1Ds connect disease aggressiveness with metabolic alterations in TNBC. Given the high level of heterogeneity among this BC subtype, TBC1Ds could represent important tools in predicting prognosis and guiding therapy decision-making.

ß-D-Glucose-Reduced Silver Nanoparticles Remodel the Tumor Microenvironment in a Murine Model of Triple-Negative Breast Cancer.

Breast cancer is the most diagnosed type of cancer worldwide and the second cause of death in women. Triple-negative breast cancer (TNBC) is the most aggressive, and due to the lack of specific targets, it is considered the most challenging subtype to treat and the subtype with the worst prognosis. The present study aims to determine the antitumor effect of beta-D-glucose-reduced silver nanoparticles (AgNPs-G) in a murine model of TNBC, as well as to study its effect on the tumor microenvironment. In an airbag model with 4T1 tumor cell implantation, the administration of AgNPs-G or doxorubicin showed antitumoral activity. Using immunohistochemistry it was demonstrated that treatment with AgNPs-G decreased the expression of PCNA, IDO, and GAL-3 and increased the expression of Caspase-3. In the tumor microenvironment, the treatment increased the percentage of memory T cells and innate effector cells and decreased CD4+ cells and regulatory T cells. There was also an increase in the levels of TNF-α, IFN-γ, and IL-6, while TNF-α was increased in serum. In conclusion, we suggest that AgNPs-G treatment has an antitumor effect that is demonstrated by its ability to remodel the tumor microenvironment in mice with TNBC.

Targeting of mutant-p53 and MYC as a novel strategy to inhibit oncogenic SPAG5 activity in triple negative breast cancer.

Triple negative breast cancer (TNBC) is an aggressive disease which currently has no effective therapeutic targets and prominent biomarkers. The Sperm Associated antigen 5 (SPAG5) is a mitotic spindle associated protein with oncogenic function in several human cancers. In TNBC, increased SPAG5 expression has been associated with tumor progression, chemoresistance, relapse, and poor clinical outcome. Here we show that high SPAG5 expression in TNBC is regulated by coordinated activity of YAP, mutant p53 and MYC. Depletion of YAP or mutant p53 proteins reduced SPAG5 expression and the recruitment of MYC onto SPAG5 promoter. Targeting of MYC also reduced SPAG5 expression and concomitantly tumorigenicity of TNBC cells. These effects of MYC targeting were synergized with cytotoxic chemotherapy and markedly reduced TNBC oncogenicity in SPAG5-expression dependent manner. These results suggest that mutant p53-MYC-SPAG5 expression can be considered as bona fide predictors of patient's outcome, and reliable biomarkers for effective anticancer therapies.

Luminous blue carbon quantum dots employing Anisomeles indica (catmint) induce apoptotic signaling pathway in triple negative breast cancer (TNBC) cells.

Herein, luminous blue carbon quantum dots (CDs) employing Anisomeles indica (Catmint) were reported with imaging, self-targeting, and therapeutic effects on triple-negative breast cancer (TNBC, MDA-MB-231) cells. The salient features of CDs generated from catmint are as follows: i) optical studies confirm CDs with excitation-dependent emission; ii) high-throughput characterization authenticates the formation of CDs with near-spherical shape with diameter ranging between 5 and 15 nm; iii) CDs induce cytotoxicity (3.22 ± 0.64 µg/ml) in triple-negative breast cancer (TNBC, MDA-MB-231) cells; iv) fluorescence microscopy demonstrates that CDs promote apoptosis by increasing reactive oxygen species (ROS) and decreasing mitochondrial membrane potential; v) CDs significantly up-regulate pro-apoptotic gene expression levels such as caspases-8/9/3. Finally, our work demonstrates that catmint-derived CDs are prospective nanotheranostics that augment cancer targeting and imaging.

Understanding tissue-resident macrophages unlocks the potential for novel combinatorial strategies in breast cancer.

Tissue-resident macrophages (TRMs) are an integral part of the innate immune system, but their biology is not well understood in the context of cancer. Distinctive resident macrophage populations are identified in different organs in mice using fate mapping studies. They develop from the yolk sac and self-maintain themselves lifelong in specific tissular niches. Similarly, breast-resident macrophages are part of the mammary gland microenvironment. They reside in the breast adipose tissue stroma and close to the ductal epithelium and help in morphogenesis. In breast cancer, TRMs may promote disease progression and metastasis; however, precise mechanisms have not been elucidated. TRMs interact intimately with recruited macrophages, cytotoxic T cells, and other immune cells along with cancer cells, deciding further immunosuppressive or cytotoxic pathways. Moreover, triple-negative breast cancer (TNBC), which is generally associated with poor outcomes, can harbor specific TRM phenotypes. The influence of TRMs on adipose tissue stroma of the mammary gland also contributes to tumor progression. The complex crosstalk between TRMs with T cells, stroma, and breast cancer cells can establish a cascade of downstream events, understanding which can offer new insight for drug discovery and upcoming treatment choices. This review aims to acknowledge the previous research done in this regard while exploring existing research gaps and the future therapeutic potential of TRMs as a combination or single agent in breast cancer.

[Neuroendocrine expression markers in triple-negative, luminal-A, luminal-B and HER2neu breast cancer]. / Expresión de marcadores neuroendócrinos en cáncer de mama triple-negativo, luminal-A, luminal-B y HER2neu.

Background: Primary breast tumors with neuroendocrine (NE) differentiation are a heterogeneous tumor group with diversity of biological behavior, with poorly defined prevalence and prognosis. Objective: To evaluate the chromogranin, synaptophysin, CD56, INSM1 markers expression prevalence and the association between NE differentiation and tumor molecular type. Material and methods: Observational, cross-sectional study which included 110 breast tissue samples with primary invasive carcinoma. Immunohistochemistry was performed for chromogranin, synaptophysin, CD56 and INMS1 markers. NE differentiation was considered with 10-90% positive cells, and NE tumor with > 90% positive cells. Results: 26.3% showed neuroendocrine differentiation. Out of these, 48.2% were luminal-A type, 24.1% luminal-B, 11.5% HER2neu, 17.2% triple-negative; 1.8% were NE tumors. Tumors were marker positive, and out of these to chromogranin in 24.5%, synaptophysin in 28.2%, CD56 in 2.7%, INSM1 in 16.4%. Synaptophysin was expressed in 17.3% luminal-A type, 6.4% luminal-B, 0.9% HER2neu, 3.6% triple-negative. NE differentiation showed association with synaptophysin expression (r = 0.586, p = 0.0001). Conclusion: The NE differentiation prevalence was 26.3% in primary invasive breast cancers, with luminal-A molecular type predominance.

Introducción: los tumores primarios de mama con diferenciación neuroendócrina (NEBC por sus siglas en inglés) son un grupo heterogéneo de tumores con diversidad de comportamiento biológico, con prevalencia y pronóstico poco definido. Objetivo: evaluar la prevalencia de la expresión los marcadores cromogranina, sinaptofisina, CD56, INSM1 y la asociación entre la diferenciación neuroendócrina y el tipo molecular del tumor. Material y métodos: estudio observacional, transversal que incluyó 110 muestras de tejido mamario con carcinoma invasor primario. Se realizó inmunohistoquímica para los marcadores cromogranina, sinaptofisina, CD56 y INMS1. La presencia 10-90% de células positivas se consideró diferenciación neuroendócrina y tumor neuroendócrino con > 90% de células positivas. Resultados: el 26.3% mostró diferenciación neuroendócrina. De estos, 48.2% fueron tipo luminal-A, 24.1% luminal-B, 11.5% HER2neu y 17.2% triple-negativo; 1.8% resultaron tumores neuroendócrinos. Los tumores presentaron marcadores positivos y de estos, 24.5% fueron a cromogranina, 28.2% a sinaptofisina, 2.7% a CD56 y 16.4% a INSM1. La sinaptofisina se expresó en 17.3% del tipo luminal-A, 6.4% luminal-B, 0.9% HER2neu, 3.6% triple-negativo. La diferenciación neuroendócrina mostró asociación con la expresión de sinaptofisina (r = 0.586, p = 0.0001). Conclusión: la prevalencia de la diferenciación neuroendócrina fue del 26.3% en los cánceres invasores primarios de mama, con predominio en el tipo molecular luminal-A.

SAHA potentiates the activity of repurposed drug promethazine loaded PLGA nanoparticles in triple-negative breast cancer cells.

Triple-negative breast cancer (TNBC) is considered the most aggressive form of breast cancer owing to the negative expression of targetable bioreceptors. Epithelial to mesenchymal transition (EMT) associated with metastatic abilities is its critical feature. As an attempt to target TNBC, nanotechnology was utilised to augment the effects of drug repurposing. Concerning that, a combination therapeutic module was structured with one of the aspects being a repurposed antihistamine, promethazine hydrochloride loaded PLGA nanoparticles. The as-synthesized nanoparticles were 217 nm in size and fluoresced at 522 nm, rendering them suitable for theranostic applications too. The second feature of the module was a common histone deacetylase inhibitor, suberoylanilide hydroxamic acid (SAHA), used as a form of pre-treatment. Experimental studies demonstrated efficient cellular internalisation and significant innate anti-proliferative potential. The use of SAHA sensitised the cells to the drug loaded nanoparticle treatment. Mechanistic studies showed increase in ROS generation, mitochondrial dysfunction followed by apoptosis. Investigations into protein expression also revealed reduction of mesenchymal proteins like vimentin by 1.90 fold; while increase in epithelial marker like E-Cadherin by 1.42 fold, thus indicating an altered EMT dynamics. Further findings also provided better insight into the benefits of SAHA potentiated targeting of tumor spheroids that mimic solid tumors of TNBC. Thus, this study paves the avenue to a more rational translational validation of combining nanotherapeutics with drug repurposing.

Thiostrepton induces spindle abnormalities and enhances Taxol cytotoxicity in MDA-MB-231 cells.

BACKGROUND: Thiostrepton (TST) is a known inhibitor of the transcription factor Forkhead box M1 (FoxM1) and inducer of heat shock response (HSR) and autophagy. TST thus may be one potential candidate of anticancer drugs for combination chemotherapy. METHODS AND RESULTS: Immunofluorescence staining of mitotic spindles and flow cytometry analysis revealed that TST induces mitotic spindle abnormalities, mitotic arrest, and apoptotic cell death in the MDA-MB-231 triple-negative breast cancer cell line. Interestingly, overexpression or depletion of FoxM1 in MDA-MB-231 cells did not affect TST induction of spindle abnormalities; however, TST-induced spindle defects were enhanced by inhibition of HSP70 or autophagy. Moreover, TST exhibited low affinity for tubulin and only slightly inhibited in vitro tubulin polymerization, but it severely impeded tubulin polymerization and destabilized microtubules in arrested mitotic MDA-MB-231 cells. Additionally, TST significantly enhanced Taxol cytotoxicity. TST also caused cytotoxicity and spindle abnormalities in a Taxol-resistant cell line, MDA-MB-231-T4R. CONCLUSIONS: These results suggest that, in addition to inhibiting FoxM1, TST may induce proteotoxicity and autophagy to disrupt cellular tubulin polymerization, and this mechanism might account for its antimitotic effects, enhancement of Taxol anticancer effects, and ability to overcome Taxol resistance in MDA-MB-231 cells. These data further imply that TST may be useful to improve the therapeutic efficacy of Taxol.

Immunohistochemical analysis of CD9, CD29 and epithelial to mesenchymal transition in triple-negative breast cancer.

BACKGROUND: Triple-negative breast carcinomas (TNBC) are a heterogeneous group of tumors with mostly aggressive behaviour and poor prognosis. In association with their aggressive behavior and chemoresistance to treatment, the concept of epithelial-mesenchymal transition (EMT) has come to the fore. CD9 and CD29 proteins are associated with EMT and may play a role in TNBC progression. Our aim was to investigate association of these markers with the lymph node metastasis, tumor grade, proliferative activity, and patient survival. PATIENTS AND METHODS: Our cohort consisted of 66 TNBC patients without neoadjuvant therapy, aged 26-81 years. The pathological tumor stages ranged from pT1b to pT3 and histological grades ranged from II to III, according to the Bloom-Richardson system. Immunohistochemical evaluation of CD9, CD29, E-cadherin, vimentin, androgen receptor and Ki-67 expression was performed semiquantitatively using the H-score. Expression of the proteins was statistically evaluated in relation to the clinicopathological parameters and survival of the patients. RESULTS: We observed lower expression of CD9 in lymph node metastases compared to the primary tumor (P = 0.021). The CD29 expression in primary tumor was significantly lower in patients with lymph node metastases compared to patients without cancer dissemination (P = 0.03). Neither CD9 nor CD29 protein expression was associated with breast cancer-specific survival (BCSS). Lower expression of E-cadherin at the periphery of the primary tumor was associated with worse BCSS (P = 0.038). Neither grade nor the presence of lymph node metastases reached significant association with the BCSS. Lower expression of E-cadherin at the periphery was also associated with higher Ki67 (Rs -0.26) and vimentin (Rs -0.33). CONCLUSION: Decreased protein expression of CD9 and CD29 were associated with lymph node metastasis growth, however, their association with survival was not proved. Lower expression of E-cadherin at the periphery of the primary tumor was associated with high proliferation and poor breast cancer-specific survival.

Synthesis and biological evaluation of imidazolium conjugated with dimethylcardamonin (DMC) as a novel potential agent against MDA-MB-231 triple-negative breast cancer cells.

A new imidazolium ionic liquid (IL) halide conjugated with dimethylcardamonin (DMC, 1), namely [Bbim]Br-DMC (3), was synthesised to improve the biological activity of the natural chalcone. DMC was isolated from seeds of Syzygium nervosum A. Cunn. ex DC. which was an effective anti-breast cancer agent. The compound 1 and 3 showed anticancer activity in MDA-MB-231 cells with IC50 values of 14.54 ± 0.99 µM and 7.40 ± 0.15 µM, respectively. MTT assay showed that compound 3 had cytotoxic effect at least two-fold greater than compound 1 but was low toxic to normal cells of Hs 578Bst. After 48 h, compound 3 at concentration of IC50 value inhibited the proliferation and induced morphological changes of MDA-MB-231 cells in a time-dependent manner. The cell cycle profile also showed that compound 3 exerted anti-proliferation activity with the cell cycle arrest at G0/G1 phase and compound 3 also induced apoptosis and reduced mitochondrial membrane potential in MDA-MB-231 cells in a dose-dependent manner. In gene expression assay, compound 3 up-regulated pro-apoptotic genes such as Bax and p53 and suppressed anti-apoptotic Bcl-2 whereas there was no effect on DNA repair gene such as PARP1. The Bax/Bcl-2 ratio was significantly increased after treated with compound 3. In the molecular docking study, the interactions between compound 3 and B-DNA structure in the minor groove region via hydrogen bonds was reported. In conclusion, [Bbim]Br-DMC or compound 3 is a potential candidate to induce apoptosis and inhibits proliferation via cell cycle arrest and decreases mitochondrial membrane of triple-negative breast cancer MDA-MB-231 cells.

Identification of Poliovirus Receptor-like 3 Protein as a Prognostic Factor in Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) represents an aggressive subtype of breast cancer, with a bad prognosis and lack of targeted therapeutic options. Characterized by the absence of estrogen receptors, progesterone receptors, and HER2 expression, TNBC is often associated with a significantly lower survival rate compared to other breast cancer subtypes. Our study aimed to explore the prognostic significance of 83 immune-related genes, by using transcriptomic data from the TCGA database. Our analysis identified the Poliovirus Receptor-Like 3 protein (PVRL3) as a critical negative prognostic marker in TNBC patients. Furthermore, we found that the Enhancer of Zeste Homolog 2 (EZH2), a well-known epigenetic regulator, plays a pivotal role in modulating PVRL3 levels in TNBC cancer cell lines expressing EZH2 along with high levels of PVRL3. The elucidation of the EZH2-PVRL3 regulatory axis provides valuable insights into the molecular mechanisms underlying TNBC aggressiveness and opens up potential pathways for personalized therapeutic intervention.

Targeting overexpressed surface proteins: A new strategy to manage the recalcitrant triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is an aggressive and heterogeneous cancer that lacks all three molecular markers, Estrogen, Progesterone, and Human Epidermal Growth Factor Receptor 2 (HER2). This unique characteristic of TNBC makes it more resistant to hormonal therapy; hence, chemotherapy and surgery are preferred. Active targeting with nanoparticles is more effective in managing TNBC than a passive approach. The surface of TNBC cells overexpresses several cell-specific proteins, which can be explored for diagnostic and therapeutic purposes. Immunohistochemical analysis has revealed that TNBC cells overexpress αVß3 integrin, Intercellular Adhesion Molecule 1 (ICAM-1), Glucose Transporter 5 (GLUT5), Transmembrane Glycoprotein Mucin 1 (MUC-1), and Epidermal Growth Factor Receptor (EGFR). These surface proteins can be targeted using ligands, such as aptamers, antibodies, and sugar molecules. Targeting the surface proteins of TNBC with ligands helps harmonize treatment and improve patient compliance. In this review, we discuss the proteins expressed, which are limited to αVß3 integrin proteins, ICAM-1, GLUT-5, MUC1, and EGFR, on the surface of TNBC, the challenges associated with the preclinical setup of breast cancer for targeted nanoformulations, internalization techniques and their challenges, suggestions to overcome the limitations of successful translation of nanoparticles, and the possibility of ligand-conjugated nanoparticles targeting these surface receptors for a better therapeutic outcome.

mRNA-Lipid Nanoparticle-Mediated Restoration of PTPN14 Exhibits Antitumor Effects by Overcoming Anoikis Resistance in Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) poses a challenging prognosis due to early metastasis driven by anoikis resistance. Identifying crucial regulators to overcome this resistance is vital for improving patient outcomes. In this study, a genome-wide CRISPR/Cas9 knockout screen in TNBC cells has identified tyrosine-protein phosphatase nonreceptor type 14 (PTPN14) as a key regulator of anoikis resistance. PTPN14 expression has shown a progressive decrease from normal breast tissue to metastatic tumors. Overexpressing PTPN14 has induced anoikis and inhibited cell proliferation in TNBC cells, while normal human breast cells are unaffected. Mechanistically, PTPN14 is identified as a key factor in dephosphorylating breast cancer antiestrogen resistance 3, a novel substrate, leading to the subsequent inhibition of PI3K/AKT and ERK signaling pathways. Local delivery of in vitro transcribed PTPN14 mRNA encapsulated by lipid nanoparticles in a TNBC mouse model has effectively inhibited tumor growth and metastasis, prolonging survival. The study underscores PTPN14 as a potential therapeutic target for metastatic TNBC, with the therapeutic strategy based on mRNA expression of PTPN14 demonstrating clinical application prospects in alleviating the burden of both primary tumors and metastatic disease.

High Glycolytic Activity Signature Reveals CCNB2 as a Key Therapeutic Target in Triple-Negative Breast Cancer.

BACKGROUND: Aerobic glycolysis and the cell cycle are well-established tumor hallmarks. Understanding their relationship could help to unravel the pathogenic mechanisms of breast cancer (BC) and suggest potential new strategies for treatment. METHODS: Glycolysis-related genes (GRGs) were downloaded from the Reactome database and screened using univariate Cox analysis. The consensus clustering method was employed to identify a glycolytic activity signature (GAS) using the Gene Expression Omnibus (GEO) dataset. A nomogram risk prediction model was constructed using coefficients from univariate Cox analysis. Immune cell infiltration was evaluated using single-sample gene set enrichment analysis (ssGSEA) and the ESTIMATE algorithm. Gene co-expression modules were created using weighted correlation network analysis (WGCNA) to identify hub genes. Gene expression in three BC cell lines was quantified using Quantitative Reverse Transcriptase Polymera (qRT-PCR). Single-cell RNA sequencing (scRNA-seq) data was used to examine the relationship between GAS and hub genes. The sensitivity of different groups to cell cycle-related clinical drugs was also examined. RESULTS: BC with high GAS (HGAS) showed high tumor grade and recurrence rate. HGAS was a prognostic indicator of worse overall survival (OS) in BC patients. HGAS BC showed more abundant immune cells and significantly higher expression of immunomodulators compared to BC with low GAS (LGAS). HGAS BC also showed enhanced cell cycle pathway, with high mRNA and protein expression levels of Cyclin B2 (CCNB2), a key component of the cell cycle pathway. Importantly, scRNA-seq analysis revealed that elevated CCNB2 expression was positively correlated with HGAS in triple-negative BC (TNBC). This was validated in clinical samples from TNBC patients. High expression of CCNB2 was found in three BC cell lines, and was also an indicator of poor prognosis. HGAS BC showed high sensitivity to several cell cycle-related clinical drugs, with 9 of these also showing activity in BC with high CCNB2 expression. CONCLUSIONS: HGAS was associated with enhanced cell cycle pathway and immune activity in BC. These results suggest that CCNB2 is a potential key therapeutic target in BC patients.

Triple negative breast cancer migration is modified by mitochondrial metabolism alteration induced by natural extracts of C. spinosa and P. alliacea.

Tumor metabolism is a crucial aspect of cancer development, and mitochondria plays a significant role in the aggressiveness and metastasis of tumors. As a result, mitochondria have become a promising therapeutic target in cancer treatment, leading to the development of compounds known as mitocans. In our group, we have consolidated the search of anticancer therapies based on natural products derived from plants, obtaining extracts such as P2Et from Caesalpinia spinosa and Anamu-SC from Petiveria alliacea, which have been shown to have antitumor activities in different cancer models. These extracts, due to their complex molecular composition, can interfere with multiple functions during tumor progression. To better understand how these natural products operate (P2Et and Anamu-SC), we constructed a model using 4T1 murine breast cancer cells with reduced expression of genes associated with glycolysis (Hexokinase-2) and mitochondrial function (Cqbp). The results indicate that the cells were more sensitive to the Anamu-SC extract, showing significant decreases in glucose consumption, ATP production, and oxygen consumption rate. Additionally, we observed changes in mitochondrial function, which reduced the cells' ability to migrate, particularly when C1qbp was silenced. This triple-negative breast cancer model allows us to identify potential natural products that can modulate tumor cell metabolism.

MANCR lncRNA Modulates Cell-Cycle Progression and Metastasis by Cis-Regulation of Nuclear Rho-GEF.

A significant number of the genetic alterations observed in cancer patients lie within nonprotein-coding segments of the genome, including regions coding for long noncoding RNAs (lncRNAs). LncRNAs display aberrant expression in breast cancer (BrCa), but the functional implications of this altered expression remain to be elucidated. By performing transcriptome screen in a triple negative BrCa (TNBC) isogenic 2D and 3D spheroid model, we observed aberrant expression of >1000 lncRNAs during BrCa progression. The chromatin-associated lncRNA MANCR shows elevated expression in metastatic TNBC. MANCR is upregulated in response to cellular stress and modulates DNA repair and cell proliferation. MANCR promotes metastasis as MANCR-depleted cells show reduced cell migration, invasion, and wound healing in vitro, and reduced metastatic lung colonization in xenograft experiments in vivo. Transcriptome analyses reveal that MANCR modulates expression and pre-mRNA splicing of genes, controlling DNA repair and checkpoint response. MANCR promotes the transcription of NET1A, a Rho-GEF that regulates DNA damage checkpoint and metastatic processes in cis, by differential promoter usage. Experiments suggest that MANCR regulates the expression of cancer-associated genes by modulating the association of various transcription factors and RNA-binding proteins. Our results identified the metastasis-promoting activities of MANCR in TNBC by cis-regulation of gene expression.