Target For Breast Cancer Therapy Research Articles

Overexpression of WT1 in all molecular subtypes of breast cancer and its impact on survival: exploring oncogenic and tumor suppressor roles of distinct WT1 isoforms.

Breast cancer is a highly heterogeneous solid tumor, posing challenges in developing targeted therapies effective for all mammary carcinoma subtypes. WT1 emerges as a promising target for breast cancer therapy due to its potential oncogenic role in various cancer types. Previous works have yielded inconsistent results. Therefore, further studies are needed to clarify the behavior of this complex gene in breast cancer. In this study, we examined WT1 expression in both Formalin Fixed Paraffin Embedded breast tumors (n = 41) and healthy adjacent tissues (n = 41) samples from newly diagnosed cases of ductal invasive breast cancer. The fold change in gene expression between the tumor and healthy tissue was determined by calculating 2-∆∆Ct. Disease-free survival analysis was computed using the Kaplan-Meier method. To identify the expression levels of different WT1 isoforms, we explored the ISOexpresso database. Relative quantification of the WT1 gene revealed an overexpression of WT1 in most cases. The percentage of patients surviving free of disease at 8years of follow-up was lower in the group overexpressing WT1 compared to the group with down-regulated WT1. Interestingly, this overexpression was observed in all molecular subtypes of invasive breast cancer, underscoring the significance of WT1 as a potential target in all these subtypes. The observed WT1 down-expression in a few cases of invasive breast cancer, associated with better survival outcomes, may correspond to the down-regulation of a particular WT1-KTS (-) isoform: the WT1 A isoform (EX5-/KTS-). The co-expression of this WT1 oncogenic isoform with a regulated WT1- tumor suppressor isoform, such as the major WT1 F isoform (EX5-/KTS +), could also explain such survival outcomes. Due to its capacity to adopt dual roles, it becomes imperative to conduct individual molecular expression profiling of the WT1 gene. Such an approach holds great promise in the development of personalized treatment strategies for breast cancer.

Computational Exploration of Naturally Occurring Flavonoids as TGF-β Inhibitors in Breast Cancer: Insights from Docking and Molecular Dynamics Simulations and In-vitro Cytotoxicity Study.

Breast cancer is a global health concern, demanding innovative treatments. Targeting the Transforming Growth Factor-beta (TGF-β) signaling pathway, pivotal in breast cancer, is a promising approach. TGF-β inhibits proliferation via G1 phase cell cycle arrest, acting as a suppressor initially, but in later stages, it promotes progression by enhancing motility, invasiveness, and metastasis formation. This study explores naturally occurring flavonoids' interactions with TGF-β. Using molecular docking against the protein's crystal structure (PDB Id: 1PY5), Gossypin showed the highest docking score and underwent molecular dynamics simulation, revealing complex flexibility and explaining how flavonoids impede TGF-β signaling in breast cancer. ADMET predictions adhered to Lipinski's rule of Five. Insights into flavonoid-TGF-β binding offer a novel angle for breast cancer treatment. Flavonoids having a good docking score like gossypin, morin, luteolin and taxifolin shown potent cytotoxic effect on breast cancer cell line, MCF-7. Understanding these interactions could inspire flavonoid-based therapies targeting TGF-β to halt breast cancer growth. These findings pave the way for personalized, targeted breast cancer therapies, offering hope against this formidable disease.

Exploring the anticancer potential of scopoletin against HER-2 positive breast cancer: an in silico molecular docking study

Cancer, defined by the unchecked growth and invasive potential of abnormal cells, remains a global health challenge. Within this context, scopoletin, a compound isolated from the leaves of Impatiens balsamina L., has garnered attention for its potential as an anti-breast cancer agent. This study employed in silico molecular docking techniques to explore scopoletin's interaction with the HER-2 protein, a known target in breast cancer therapy. The docking analysis revealed that scopoletin exhibits affinity towards the HER-2 protein, with a binding energy of -6.3 kcal/mol. Notably, the binding energy of scopoletin is comparable to that of gefitinib, an established cancer drug, further underscoring its potential therapeutic value.

Identification of potential therapeutic targets for breast cancer using Mendelian randomization analysis and drug target prediction.

Breast cancer stands as the foremost cause of cancer-related mortality among women, presenting a substantial economic impact on society. The limitations in current therapeutic options, coupled with poor patient tolerance, underscore the urgent need for novel treatments. Our study embarked on a genomic association exploration of breast cancer, leveraging whole-genome sequencing data from the Finngen database, complemented by expression quantitative trait loci (eQTL) insights from the eQTLGen and GTEx Consortiums. An initial investigation was conducted through summary-based Mendelian randomization (MR) to pinpoint primary eQTLs. Analysis of blood specimens revealed 103 eQTLs significantly correlated with breast cancer. Focusing our efforts, we identified 19 candidates with potential therapeutic significance. Further scrutiny via two-sample MR pinpointed UROD, LMO4, HORMAD1, and ZSWIM5 as promising targets for breast cancer therapy. Our research sheds light on new avenues for the treatment of breast cancer, highlighting the potential of genomic association studies in uncovering viable therapeutic targets.

Sphingosine kinase 1, a potential drug target for breast cancer therapy in in silico models: A molecular docking verification

An important aspect of breast cancer therapy is selection of drug targets in the proliferating cells. Only few studies have focused on spingoshine kinase1 (SphK1); a potential target present in the cancer cells to bind with drug molecules. The structure and physicochemical properties of SphK1 were retrieved. The information of top 12 anticancer drugs were collected from National Cancer Institute (NCI) database and considered as reference drugs based on their drug likeness properties. The drug likeness property values of these drugs are in the range of 0.001 to 2.33, -0.7 to 7.4, -2 to -5.5, 2 to 13, 1 to 6 and 33 to 205 respectively for water solubility, partition coefficient, molar solubility, hydrogen acceptor and donor counts and polar surface area. The values were compared with 15 experimental drugs which were taken from a published article. The range of drug likeness property values of both groups match with each other. SphK1 shows strong binding affinity to the experimental drugs in the range of -8.8 and -5.1. Herein, we describe an effective solution for treating breast cancer by targeting the tumor marker, SphK1.

Recent progress of CDK4/6 inhibitors' current practice in breast cancer.

Dysregulated cellular proliferation represents a hallmark feature across all cancers. Aberrant activation of the cyclin-dependent kinase 4 and 6 (CDK4/6) pathway, independent of mitogenic signaling, engenders uncontrolled breast cancer cell proliferation. Consequently, the advent of CDK4/6 inhibition has constituted a pivotal milestone in the realm of targeted breast cancer therapy. The combination of CDK4/6 inhibitors (CDK4/6i) with endocrine therapy (ET) has emerged as the foremost therapeutic modality for patients afflicted with hormone receptor-positive (HR + )/HER2-negative (HER2-) advanced breast cancer. At present, the Food and Drug Administration (FDA) has sanctioned various CDK4/6i for employment as the primary treatment regimen in HR + /HER2- breast cancer. This therapeutic approach has demonstrated a substantial extension of progression-free survival (PFS), often amounting to several months, when administered alongside endocrine therapy. Within this comprehensive review, we systematically evaluate the utilization strategies of CDK4/6i across various subpopulations of breast cancer and explore potential therapeutic avenues following disease progression during application of CDK4/6i therapy.

Estrogen-related receptor alpha (ERRα) promotes the migration, invasion and angiogenesis of breast cancer stem cell-like cells.

Breast cancer progression, metastasis and recurrence are largely driven by breast cancer stem cells (BCSCs), which constitute a subset of tumor cells exhibiting stem cell characteristics. In this study, we evaluated the role of estrogen-related receptor alpha (ERRα) in the migration, invasion and angiogenesis of BCSCs. The inhibition of ERRα using XCT790 or knockdown of ERRα using shRNA inhibited the mammosphere formation efficiency, as well as the migration and invasion of BCSCs derived from the mammospheres of MCF7 and MDA-MB-231 (MB231) cells. Conversely, the overexpression of ERRα significantly increased the migration and invasion of BCSCs derived from the mammosphere. In addition, the XCT790 treatment or shERRα significantly downregulated the epithelial-mesenchymal transition (EMT), as evidenced by the downregulation in the expression of vimentin, Snail, Slug and N-cadherin in the mammospheres of MCF7 and MB231 cells. The chorioallantoic membrane assay showed that the conditioned media from XCT790-treated and shERRα cells significantly inhibited blood vessel formation and vessel length. Furthermore, XCT790 treatment or shERRα also downregulated the expression of molecular markers of angiogenesis, such as VEGF-A and Ang-2 in the mammospheres. Conversely, the overexpression of ERRα in MCF7 cells significantly increased both EMT and angiogenesis. These findings suggest that ERRα inhibits the migration, invasion and angiogenesis of BCSCs, suggesting as a potential target for breast cancer therapy.

FEN1 Inhibition as a Potential Novel Targeted Therapy against Breast Cancer and the Prognostic Relevance of FEN1.

To improve breast cancer treatment and to enable new strategies for therapeutic resistance, therapeutic targets are constantly being studied. Potential targets are proteins of DNA repair and replication and genomic integrity, such as Flap Endonuclease 1 (FEN1). This study investigated the effects of FEN1 inhibitor FEN1-IN-4 in combination with ionizing radiation on cell death, clonogenic survival, the cell cycle, senescence, doubling time, DNA double-strand breaks and micronuclei in breast cancer cells, breast cells and healthy skin fibroblasts. Furthermore, the variation in the baseline FEN1 level and its influence on treatment prognosis was investigated. The cell lines show specific response patterns in the aspects studied and have heterogeneous baseline FEN1 levels. FEN1-IN-4 has cytotoxic, cytostatic and radiosensitizing effects, expressed through increasing cell death by apoptosis and necrosis, G2M share, senescence, double-strand breaks and a reduced survival fraction. Nevertheless, some cells are less affected by the cytotoxicity and fibroblasts show a rather limited response. In vivo, high FEN1 mRNA expression worsens the prognosis of breast cancer patients. Due to the increased expression in breast cancer tissue, FEN1 could represent a new tumor and prognosis marker and FEN1-IN-4 may serve as a new potent agent in personalized medicine and targeted breast cancer therapy.

MiRNA-449c-5p regulates the JAK-STAT pathway in inhibiting cell proliferation and invasion in human breast cancer cells by targeting ERBB2.

Breast cancer is a highly prevalent disease worldwide, and early diagnosis and treatment could reduce the mortality rate of breast cancer patients. microRNAs (miRNA) have been shown to regulate the occurrences and progression of many types of cancers. Thus, it is crucial to find novel biomarkers in breast cancer. miR-449c-5p acted as a biomarker in non-small cell lung cancer, gastric carcinoma, and so forth. ERBB2 is an ideal target for breast cancer therapy. However, the molecular mechanisms between miR-449c-5p and ERBB2 in breast cancer remain poorly understood. Our study focused on the regulatory role of miR-449c-5p in breast cancer and its targeting relationship with ERBB2. The miR-449c-5p expression in breast cancer tissue and normal tissue was searched from the online database (Starbase). The clinical prognosis of miR-449c-5p and ERBB2 was predicted by using the Kaplan-Meier analysis method. The expression of miR-449c-5p mimics and inhibitors was measured by qRT-PCR. T47D cells were transfected with miR-449c-5p mimics and miR-449c-5p inhibitors. After that, CCK-8, colony formation assays and Transwell assays were used to evaluate the cell proliferation ability, migration and invasion. Whether ERBB2 was the target gene of the miR-449c-5p was predicted by Starbase and verified by dual-luciferase activity assay. In addition, protein levels and the relationship between signalling pathways were measured and validated using western blotting analysis. We confirmed that miR-449c-5p was highly expressed in breast cancer tissue, and its downregulation was linked with poor prognosis. Overexpression of miR-449c-5p inhibited the proliferation, migration and invasion of breast cancer cells. ERBB2 was a target of miR-449c-5p. The invasion, migration, and proliferation of breast cancer cells were inhibited by miR-449c-5p/ERBB2 through JAK-STAT. This study demonstrated that miR-449c-5p inhibits breast cancer cell proliferation, migration and invasion by targeting ERBB2 via JAK/STAT, which means miR-449c-5p, is a potential biomarker for breast cancer and provides a novel insight for diagnosis.

Abstract A012: Mre11 mediates cGAS activation and tumor suppression through ZBP1-dependent necroptosis in breast cancer

Abstract Oncogene-induced replication stress leads to endogenous DNA damage, activating the cGAS/STING signaling pathway, a critical player in tumor suppression. The exact mechanism underlying cGAS activation, however, remains unclear due to the continual inhibition of cGAS by its high-affinity interaction with the histone acidic patch (AP), which sterically prevents its activation by double-stranded DNA (dsDNA). In this investigation, we elucidate the significant role of the DNA double-strand break sensor, Mre11, in regulating cGAS activation and thereby inhibiting mammary tumorigenesis. Our data reveal that the binding of the Mre11-Rad50-Nbn (MRN) complex to nucleosome fragments is crucial to liberate cGAS from AP-mediated sequestration, facilitating its subsequent activation by dsDNA. Consequently, Mre11 emerges as a vital component in the cGAS activation process, responding to oncogenic stress, cytosolic dsDNA, and ionizing radiation. Moreover, we highlight the ramifications of Mre11-dependent cGAS activation which fosters ZBP1/RIPK3/MLKL-mediated necroptosis, a vital process in curtailing oncogenic proliferation and breast tumorigenesis. Significantly, our study identifies a strong correlation between the downregulation of ZBP1 in human triple-negative breast cancer and increased genomic instability, suppressed immune response, and adverse patient prognosis. Our findings firmly establish Mre11 as a pivotal mediator connecting DNA damage to cGAS activation, thereby facilitating tumor suppression through ZBP1-dependent necroptosis, offering a promising avenue for targeted breast cancer therapies. Citation Format: Minguk Jo, Rashmi J. Kumar, Chien-Chu Lin, Joshua A. Boyer, Jamshaid A. Shahir, Katerina Fagan-Solis, Dennis A. Simpson, Cheng Fan, Christine E. Foster, Anna M. Goddard, Lynn M. Lerner, Simon W. Ellington, Qinhong Wang, Ying Wang, Alice Y. Ho, Pengda Liu, Charles M. Perou, Qi Zhang, Robert K. McGinty, Jeremy E. Purvis, Gaorav P. Gupta. Mre11 mediates cGAS activation and tumor suppression through ZBP1-dependent necroptosis in breast cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: DNA Damage Repair: From Basic Science to Future Clinical Application; 2024 Jan 9-11; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2024;84(1 Suppl):Abstract nr A012.

Nitro Compounds Inhibit Breast Cancer Cell Proliferation, Migration, and Colony Formation: Molecular Docking, Molecular Dynamics Simulations and Pharmacological Properties

AbstractIn this study, the concept of combined in vitro and in silico studies were utilized by using some synthesized nitro bearing compounds. The anticancer activities of the studied compounds were performed by using colony formation analysis, cell cytotoxicity, and migration. Nitro group containing two compounds were analyzed using Hoechst staining to indicate the morphological changes on the nuclei of cancer cells under fluorescence microscopy. Scanning electron microscopy (SEM) analysis was performed with N,N‐dibutyl‐nitro‐substituted compound. Nitro containing anticancer agents were shown the inhibition at 1.5 μM and 2 μM concentrations, and nuclear apoptosis was detected. In addition, cell‐to‐cell interaction on MDA‐MB‐231 cells was broken and observed morphologic changes following the treatment with N,N‐dibutyl‐nitro‐substituted compound at the effective doses. In general, the other nitro compounds showed cell cytotoxicity at 5 μM, 10 μM, and 20 μM. Two hits as anticancer agents were determined as potential interleukin‐1 receptor‐associated kinase 1 (IRAK1) and interleukin‐1 receptor‐associated kinase 4 (IRAK4) inhibitor candidates. Molecular docking and molecular dynamics (MD) simulations studies will provide that the binding patterns with specific residues such as Met265, Tyr284 of the IRAK family members, and these will contribute to further in vitro and in vivo studies for targeted breast cancer therapy.

Enhanced anti-tumor efficacy and tumor accumulation of Tamoxifen through cRGD functionalized cholesterol based lipopolymeric nanoparticles for targeted breast cancer therapy

Targeting ligand mediated drug delivery systems hold promise for enhancing the anti-tumor efficacy and suppressing the off-target effects of chemotherapeutic molecules. The current study aims at the development of a peptide conjugated cholesterol based lipopolymeric nanoparticles for delivery of Tamoxifen (TMX). cRGD conjugated, cholesterol containing lipopolymers were successfully synthesized by maleimide-thiol coupling and characterized by 1H NMR. Emulsion-solvent evaporation technique was employed to formulate TMX loaded cRGD conjugated lipopolymeric nanoparticles which were further analyzed to determine the particle size, encapsulation efficiency and release kinetics and compared with TMX loaded mPEG-MTC-Chol nanoparticles. The cRGD conjugated lipopolymeric nanoparticles exhibited particle size ∼133.61 ± 4.70 nm with 43.86 ± 1.85 % encapsulation efficiency. Interestingly, the presence of cRGD greatly enhanced the cellular internalization and inhibitory activity of lipopolymeric nanoparticles in 4T1 cells with an IC50 value of ∼19.04 μM in comparison to TMX loaded mPEG-MTC-Chol NP (∼28.07 μM) Further, as evidenced by the rise in sub-diploid DNA content, TMX loaded cRGD-PEG-MTC Chol nanoparticles triggered apoptosis ∼2.34 fold greater than TMX loaded mPEG-MTC-Chol nanoparticles. Additionally, cRGD-PEG-MTC-Chol nanoparticles demonstrated longer half-life (∼1.84 fold) and improved bioavailibility (∼2.1 fold) and a ∼2 fold increment in drug concentration within the isolated tumor tissues when administered as cRGD-PEG-MTC-Chol NP vs mPEG-MTC-Chol NP in tumor bearing mice. This could be majorly attributed to integrin mediated receptor endocytosis which concurrently accounted for significant anti-tumor effects in EAC breast cancer mouse model.

Selective HDAC3 Inhibitors with Potent In Vivo Antitumor Efficacy against Triple-Negative Breast Cancer.

HDAC3 modulation shows promise for breast cancer, including triple-negative cases. Novel pyrazino-hydrazide-based HDAC3 inhibitors were designed and synthesized. Lead compound 4i exhibited potent HDAC3 inhibition (IC50 = 14 nM) with at least 121-fold selectivity. It demonstrated strong cytotoxicity against triple-negative breast cancer cells (IC50: 0.55 μM for 4T1, 0.74 μM for MDA-MB-231) with least normal cell toxicity. Metabolically stable 4i displayed a superior pharmacokinetic profile. A dose-dependent therapeutic efficacy of 4i was observed in a tumor-bearing mouse model. The biomarker analysis with tumor tissues displayed enhanced acetylation on Ac-H3K9, Ac-H3K27, and Ac-H4K12 compared to Ac-tubulin and Ac-SMC3 indicating HDAC3 selectivity of 4i in vivo. The immunoblotting study with tumor tissue showed upregulation of apoptotic proteins caspase-3, caspase-7, and cytochrome c and the downregulation of proliferation markers Bcl-2, CD44, EGFR, and Ki-67. Compound 4i represents a promising candidate for targeted breast cancer therapy, particularly for cases with triple-negative breast cancer.

Gold Nanomaterial System That Enables Dual Photothermal and Chemotherapy for Breast Cancer.

This study involves the fabrication and characterization of a multifunctional therapeutic nanocomposite system, as well as an assessment of its in vitro efficacy for breast cancer treatment. The nanocomposite system combines gold nanorods (GNRs) and gold nanoclusters (GNCs) to enable a combination of photothermal therapy and doxorubicin-based chemotherapy. GNRs of various sizes but exhibiting similar absorbance spectra were synthesized and screened for photothermal efficiency. GNRs exhibiting the highest photothermal efficiency were selected for further experiments. GNCs were synthesized in bovine serum albumin (BSA) and integrated into citrate-capped GNRs using layer-by-layer assembly. Glutaraldehyde crosslinking with the lysine residues in BSA was employed to immobilize the GNCs onto the GNRs, forming a stable "soft gel-like" structure. This structure provided binding sites for doxorubicin through electrostatic interactions and enhanced the overall structural stability of the nanocomposite. Additionally, the presence of GNCs allowed the nanocomposite system to emit robust fluorescence in the range of ~520 nm to 700 nm for self-detection. Hyaluronic acid was functionalized on the exterior surface of the nanocomposite as a targeting moiety for CD44 to improve the cellular internalization and specificity for breast cancer cells. The developed nanocomposite system demonstrated good stability in vitro and exhibited a pH- and near-infrared-responsive drug release behavior. In vitro studies showed the efficient internalization of the nanocomposite system and reduced cellular viability following NIR irradiation in MDA-MB-231 breast cancer cells. Together, these results highlight the potential of this nanocomposite system for targeted breast cancer therapy.

Fractions of Methanol Extracts from the Resurrection Plant Haberlea rhodopensis Have Anti-Breast Cancer Effects in Model Cell Systems

Breast cancer is among the most problematic diseases and a leading cause of death in women. The methods of therapy widely used, so far, are often with many side effects, seriously hampering patients’ quality of life. To overcome these constraints, new cancer treatment alternatives are constantly tested, including bioactive compounds of plant origin. Our aim was to study the effects of Haberlea rhodopensis methanol extract fractions on cell viability and proliferation of two model breast cancer cell lines with different characteristics. In addition to the strong reduction in cell viability, two of the fractions showed significant influence on the proliferation rate of the hormone receptor expressing MCF7 and the triple negative MDA-MB231 breast cancer cell lines. No significant effects on the benign MCF10A cell line were observed. We applied a large scale non-targeted approach to purify and identify highly abundant compounds from the active fractions of H. rhodopensis extracts. By the combined NMR/MS approach, myconoside was identified in the fractions and hispidulin 8-C-(6-O-acetyl-2″-O-syringoyl-β-glucopyranoside) was found in one of them. We further performed molecular docking analysis of possible myconoside interactions with several proteins, important for breast cancer proliferation. High probability of binding was established for GLUT1 transporter, estrogen receptor and MYST acetyltransferase. Our results are a good background for future studies on the use of myconoside for targeted breast cancer therapy.

CXCR4-Targeted Necrosis-Inducing Peptidomimetic for Treating Breast Cancer.

Triple-negative breast cancer is an aggressive subtype with a high recurrence rate, potential for metastasis, and a poor prognosis. The chemokine receptor, CXCR4, is a promising molecular target in breast cancer therapy. Here, we have developed a CXCR4-targeted antitumor peptidomimetic (named CTCE-KLAK), which is a fusion of the CXCR4 receptor antagonist CTCE-9908 and the D-form of proapoptotic peptide (KLAKLAK)2, for the treatment of breast cancer. First, we investigated the in vitro antitumor activity of CTCE-KLAK against various breast cancer cells and noncancerous mammary epithelial cells. CTCE-KLAK showed cell-selective cytotoxicity and induced rapid necrotic cell death in breast cancer cells but not in normal cells. In contrast, unconjugated peptides such as the carboxylate analogues of CTCE-9908 and D(KLAKLAK)2 were not cytotoxic to these cells. The tumor selectivity of CTCE-KLAK for cytotoxic activity depends on its internalization into tumor cells. There was no cleavage of caspase-3, caspase-7, or PARP1 in CTCE-KLAK-treated cells. In addition, cell death by CTCE-KLAK was not prevented by z-VAD-fmk, a pan-caspase inhibitor that inhibits cisplatin-induced cell death. These data indicate that the CTCE-KLAK conjugate is a cell-selective inducer of necrosis. Furthermore, we evaluated the in vivo antitumor activity of CTCE-KLAK in the 4T1 mouse metastatic breast cancer model. Intravenous administration of CTCE-KLAK significantly inhibited tumor growth and lung metastasis. Together, these findings suggest that the necrosis-inducing peptidomimetic CTCE-KLAK is a promising CXCR4-targeted agent for treating triple-negative breast cancer.

Cyclic RGD-Functionalized pH/ROS Dual-Responsive Nanoparticle for Targeted Breast Cancer Therapy.

Breast cancer is the most common malignant tumor in women and is a big challenge to clinical treatment due to the high morbidity and mortality. The pH/ROS dual-responsive nanoplatforms may be an effective way to significantly improve the therapeutic efficacy of breast cancer. Herein, we report a docetaxel (DTX)-loaded pH/ROS-responsive NP that could achieve active targeting of cancer cells and selective and complete drug release for effective drug delivery. The pH/ROS-responsive NPs were fabricated using nanocarriers that consist of an ROS-responsive moiety (4-hydroxymethylphenylboronic acid pinacol ester, HPAP), cinnamaldehyde (CA, an aldehyde organic compound with anticancer activities) and cyclodextrin (α-CD). The NPs were loaded with DTX, modified with a tumor-penetration peptide (circular RGD, cRGD) and named DTX/RGD NPs. The cRGD could promote DTX/RGD NPs penetration into deep tumor tissue and specifically target cancer cells. After internalization by cancer cells through receptor-mediated endocytosis, the pH-responsive acetal was cleaved to release CA in the lysosomal acidic environment. Meanwhile, the high ROS in tumor cells induced the disassembly of NPs with complete release of DTX. In vitro cellular assays verified that DTX/RGD NPs could be effectively internalized by 4T1 cells, obviously inducing apoptosis, blocking the cell cycle of 4T1 cells and consequently, killing tumor cells. In vivo animal experiments demonstrated that the NPs could target to the tumor sites and significantly inhibit the tumor growth in 4T1 breast cancer mice. Both in vitro and in vivo investigations demonstrated that DTX/RGD NPs could significantly improve the antitumor effect compared to free DTX. Thus, the DTX/RGD NPs provide a promising strategy for enhancing drug delivery and cancer therapy.

3‐Methoxy‐Pyrrole‐Based Small Molecule Damages Mitochondria to Instigate Apoptosis in Breast Cancer Cells

AbstractMitochondrion has been implicated in the development and progression of breast cancer, making it an unconventional target for the anti‐cancer therapy. As a result, there is a need to explore novel small molecules for next generation breast cancer therapy. Towards this endeavour, herein, we have identified a novel 3‐methoxy‐pyrrole‐based small molecule from a synthetic library. Confocal fluorescence microscopy studies revealed that, this lead small molecule induced mitochondrial damage and generated reactive oxygen species (ROS) in the MCF7 breast cancer cells. Small molecule based mitochondrial impairment subsequently triggered cell cycle arrest and nuclear DNA damage followed by apoptosis leading remarkable cell killing and inhibition in the colony formation in MCF7 cells. Moreover, this 3‐methoxy‐pyrrole killed drug resistant MDA‐MB‐231 triple negative breast cancer cells and OVCAR8 ovarian cancer cells efficiently. This novel small molecule can open a new direction towards mitochondria targeted breast cancer therapy in future.

Chondroitin/Lactoferrin-dual functionalized pterostilbene-solid lipid nanoparticles as targeted breast cancer therapy

Breast cancer remains the leading cause of cancer-associated mortality in women. Research investigating novel therapeutic approaches is thus crucial, including phytotherapeutics. Pterostilbene (PTS) is a phytochemical agent with promising efficacy against breast cancer. Poor solubility, low bioavailability and chemical instability are major drawbacks compromising PTS functionality. Herein, novel PTS-loaded solid lipid nanoparticles (PTS-SLNs) were fabricated using the ultrasonication technique. Dual-functionalization with lactoferrin (Lf) and chondroitin-sulfate (CS; CS/Lf/PTS-SLNs) was adopted as active-targeting approach. CS/Lf/PTS-SLNs demonstrated nanoparticle-size (223.42 ± 18.71 nm), low PDI (0.33 ± 0.017), acceptable zeta potential (-11.85 ± 0.07 mV) and controlled release (72.93 ± 2.93% after 24 h). In vitro studies on triple-negative MDA-MB-231 revealed prominent cytotoxicity of CS/Lf/PTS-SLNs (2.63-fold IC50 reduction), higher anti-migratory effect and cellular uptake relative to PTS-solution. The in vivo anti-tumor efficacy in an orthotopic cancer model verified the superiority of CS/Lf/PTS-SLNs; achieving 2.4-fold decrease in tumor growth compared to PTS-solution. On the molecular level, CS/Lf/PTS-SLNs enhanced suppression of VEGF, down-regulated cyclin D1 and upregulated caspase-3 and BAX, compared to PTS-solution. Also, immunohistochemical assay confirmed the higher anti-tumorigenic effect of CS/Lf/PTS-SLNs (5.87-fold decrease in Bcl-2 expression) compared to PTS-solution. Our findings highlight CS/Lf/PTS-SLNs as a promising nanoplatform for phytotherapeutic targeted-breast cancer therapy.

DYNLT1 promotes mitochondrial metabolism to fuel breast cancer development by inhibiting ubiquitination degradation of VDAC1

BackgroundMitochondrial metabolism has been proposed as an attractive target for breast cancer therapy. The discovery of new mechanisms underlying mitochondrial dysfunction will facilitate the development of new metabolic inhibitors to improve the clinical treatment of breast cancer patients. DYNLT1 (Dynein Light Chain Tctex-Type 1) is a key component of the motor complex that transports cellular cargo along microtubules in the cell, but whether and how DYNLT1 affects mitochondrial metabolism and breast cancer has not been reported.MethodsThe expression levels of DYNLT1 were analyzed in clinical samples and a panel of cell lines. The role of DYNLT1 in breast cancer development was investigated using in vivo mouse models and in vitro cell assays, including CCK-8, plate cloning and transwell assay. The role of DYNLT1 in regulating mitochondrial metabolism in breast cancer development is examined by measuring mitochondrial membrane potential and ATP levels. To investigate the underlying molecular mechanism, many methods, including but not limited to Co-IP and ubiquitination assay were used.ResultsFirst, we found that DYNLT1 was upregulated in breast tumors, especially in ER + and TNBC subtypes. DYNLT1 promotes the proliferation, migration, invasion and mitochondrial metabolism in breast cancer cells in vitro and breast tumor development in vivo. DYNLT1 colocalizes with voltage-dependent anion channel 1 (VDAC1) on mitochondria to regulate key metabolic and energy functions. Mechanistically, DYNLT1 stabilizes the voltage-dependent anion channel 1 (VDAC1) by hindering E3 ligase Parkin-mediated VDAC1 ubiquitination and degradation.ConclusionOur data demonstrate that DYNLT1 promotes mitochondrial metabolism to fuel breast cancer development by inhibiting Parkin-mediated ubiquitination degradation of VDAC1. This study suggests that mitochondrial metabolism can be exploited by targeting the DYNLT1-Parkin-VDAC1 axis to improve the ability of metabolic inhibitors to suppress cancers with limited treatment options, such as triple-negative breast cancer (TNBC).