Rutin induces endoplasmic reticulum stress-associated apoptosis in human triple-negative breast carcinoma MDA-MB-231 cells – In vitro and in silico docking studies

Rutin is a bioactive compound that possesses anti-tumor activities through triggering apoptosis. Triple-negative breast cancer (TNBC) is insensitive to targeted anti-tumoral drugs, and drug resistance in TNBC poses a challenge for a successful cure. The accumulation of misfolded proteins in the lumen of the endoplasmic reticulum (ER) results in cellular stress that initiates a specialized response designated as the unfolded protein response. This study aimed to find potential ER stress targets in triple-negative breast cancer. The viability of cells was evaluated using an MTT assay. Cell migration and proliferation were done by wound scratch and colony formation assay. Cell cycle detection, measurement of ER stress, mitochondrial membrane potential disruption, and cell death identification was performed using flow cytometry. The interaction of rutin with ER stress proteins is predicted using in silico docking. The pattern of gene expression was determined by qRT-PCR. The elevated rate of cell viability, cell cycle arrest, ER stress, MMP, and apoptotic induction was observed in combination treatment. Rutin exhibited the highest glide score with ASK1 and JNK. The results of qRT-PCR showed that rutin induced apoptosis through upregulation of ASK1 and JNK. The present study provides strong evidence supporting an important role of the ER stress response in mediating rutin-induced apoptosis in triple-negative breast cancer.     

Benzo[f]indole-4,9-dione Derivatives Effectively Inhibit the Growth of Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is a subtype of breast cancer with poor clinical outcome, and currently no effective targeted therapies are available. Indole compounds have been shown to have potential antitumor activity against various cancer cells. In the present study, we found that new four benzo[f]indole-4,9-dione derivatives reduce TNBC cell viability by reactive oxygen species (ROS) accumulation stress in vitro. Further analyses showed that LACBio1, LACBio2, LACBio3 and LACBio4 exert cytotoxic effects on MDA-MB 231 cancer cell line by inducing the intrinsic apoptosis pathway, activating caspase 9 and Bax/Bcl-2 pathway in vitro. These results provide evidence that these new four benzo[f]indole-4,9-dione derivatives could be potential therapeutic agents against TNBC by promoting ROS stress-mediated apoptosis through intrinsic-pathway caspase activation.     

Pharmaceutical Drug Metformin and MCL1 Inhibitor S63845 Exhibit Anticancer Activity in Myeloid Leukemia Cells via Redox Remodeling

Metabolic landscape and sensitivity to apoptosis induction play a crucial role in acute myeloid leukemia (AML) resistance. Therefore, we investigated the effect of metformin, a medication that also acts as an inhibitor of oxidative phosphorylation (OXPHOS), and MCL-1 inhibitor {"type":"entrez-nucleotide","attrs":{"text":"S63845","term_id":"400540","term_text":"S63845"}}S63845 in AML cell lines NB4, KG1 and chemoresistant KG1A cells. The impact of compounds was evaluated using fluorescence-based metabolic flux analysis, assessment of mitochondrial Δψ and cellular ROS, trypan blue exclusion, Annexin V-PI and XTT tests for cell death and cytotoxicity estimations, also RT-qPCR and Western blot for gene and protein expression. Treatment with metformin resulted in significant downregulation of OXPHOS; however, increase in glycolysis was observed in NB4 and KG1A cells. In contrast, treatment with {"type":"entrez-nucleotide","attrs":{"text":"S63845","term_id":"400540","term_text":"S63845"}}S63845 slightly increased the rate of OXPHOS in KG1 and KG1A cells, although it profoundly diminished the rate of glycolysis. Generally, combined treatment had stronger inhibitory effects on cellular metabolism and ATP levels. Furthermore, results revealed that treatment with metformin, {"type":"entrez-nucleotide","attrs":{"text":"S63845","term_id":"400540","term_text":"S63845"}}S63845 and their combinations induced apoptosis in AML cells. In addition, level of apoptotic cell death correlated with cellular ROS induction, as well as with downregulation of tumor suppressor protein MYC. In summary, we show that modulation of redox-stress could have a potential anticancer activity in AML cells.     

Novel Semi-Synthetic Cu (II)–Cardamonin Complex Exerts Potent Anticancer Activity against Triple-Negative Breast and Pancreatic Cancer Cells via Inhibition of the Akt Signaling Pathway

Cardamonin is a polyphenolic natural product that has been shown to possess cytotoxic activity against a variety of cancer cell lines. We previously reported the semi-synthesis of a novel Cu (II)–cardamonin complex (19) that demonstrated potent antitumour activity. In this study, we further investigated the bioactivity of 19 against MDA-MB-468 and PANC-1 cancer cells in an attempt to discover an effective treatment for triple-negative breast cancer (TNBC) and pancreatic cancer, respectively. Results revealed that 19 abolished the formation of MDA-MB-468 and PANC-1 colonies, exerted growth-inhibitory activity, and inhibited cancer cell migration. Further mechanistic studies showed that 19 induced DNA damage resulting in gap 2 (G2)/mitosis (M) phase arrest and microtubule network disruption. Moreover, 19 generated reactive oxygen species (ROS) that may contribute to induction of apoptosis, corroborated by activation of caspase-3/7, PARP cleavage, and downregulation of Mcl-1. Complex 19 also decreased the expression levels of p-Akt and p-4EBP1, which indicates that the compound exerts its activity, at least in part, via inhibition of Akt signalling. Furthermore, 19 decreased the expression of c-Myc in PANC-1 cells only, which suggests that it may exert its bioactivity via multiple mechanisms of action. These results demonstrate the potential of 19 as a therapeutic agent for TNBC and pancreatic cancer.     

PEGylated anti-MUC1 aptamer-doxorubicin complex for targeted drug delivery to MCF7 breast cancer cells

Targeted drug delivery is especially important in cancer treatment as many anti-cancer drugs are non-specific and highly toxic to both cancer and normal cells. The targeted drug delivery of DOX to the MUC1-expressing breast cancer cell line (MCF7) was obtained using APT as a carrier. Modification of the APT-DOX complex by PEG increases the survivability of the macrophage control (RAW 264.7) by about six-fold as compared to free DOX treatment without significantly affecting the cytotoxicity toward the target cell line. Thus, PEG-APT-DOX is potentially a new therapeutic agent for targeted drug delivery to MUC1-expressing cell lines.     

Molecularly Imprinted Nanobeacons Redirect Innate Immune Killing towards Triple Negative Breast Cancer

Harnessing innate immunity is an appealing strategy for cancer treatment. Herein, we report a new strategy called molecularly imprinted nanobeacons (MINBs) for redirecting innate immune killing towards triple-negative breast cancer (TNBC). The MINBs were molecularly imprinted nanoparticles with the N-epitope of glycoprotein nonmetastatic B (GPNMB) as the template and grafted with plentiful fluorescein moieties as the hapten. The MINBs could tag the TNBC cells via binding with GPNMB and thereby provide navigation for recruiting hapten-specific antibodies. The gathered antibodies could further trigger effective Fc-domain-mediated immune killing towards the tagged cancer cells. In vivo experiments showed that the TNBC growth was significantly inhibited after MINBs treatment by intravenous injection as compared with control groups. This study not only opens a new access for redirecting innate immunity towards TNBC but also paves the way for innate immunity-based therapy of other diseases.     

Anticancer Effects and Molecular Action of 7-α-Hydroxyfrullanolide in G2/M-Phase Arrest and Apoptosis in Triple Negative Breast Cancer Cells

Triple negative breast cancer (TNBC) is a breast cancer subtype characterized by the absence of estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2 expression. TNBC cells respond poorly to targeted chemotherapies currently in use and the mortality rate of TNBC remains high. Therefore, it is necessary to identify new chemotherapeutic agents for TNBC. In this study, the anti-cancer effects of 7-α-hydroxyfrullanolide (7HF), derived from Grangea maderaspatana, on MCF-7, MDA-MB-231 and MDA-MB-468 breast cancer cells were assessed using MTT assay. The mode of action of 7HF in TNBC cells treated with 6, 12 and 24 µM of 7HF was determined by flow cytometry and propidium iodide (PI) staining for cell cycle analysis and annexin V/fluorescein isothiocyanate + PI staining for detecting apoptosis. The molecular mechanism of action of 7HF in TNBC cells was investigated by evaluating protein expression using proteomic techniques and western blotting. Subsequently, 7HF exhibited the strongest anti-TNBC activity toward MDA-MB-468 cells and a concomitantly weak toxicity toward normal breast cells. The molecular mechanism of action of low-dose 7HF in TNBC cells primarily involved G2/M-phase arrest through upregulation of the expression of Bub3, cyclin B1, phosphorylated Cdk1 (Tyr 15) and p53-independent p21. Contrastingly, the upregulation of PP2A-A subunit expression may have modulated the suppression of various cell survival proteins such as p-Akt (Ser 473), FoxO3a and β-catenin. The concurrent apoptotic effect of 7HF on the treated cells was mediated via both intrinsic and extrinsic modes through the upregulation of Bax and active cleaved caspase-7–9 expression and downregulation of Bcl-2 and full-length caspase-7–9 expression. Notably, the proteomic approach revealed the upregulation of the expression of pivotal protein clusters associated with G1/S-phase arrest, G2/M-phase transition and apoptosis. Thus, 7HF exhibits promising anti-TNBC activity and at a low dose, it modulates signal transduction associated with G2/M-phase arrest and apoptosis.     

Current Photoactive Molecules for Targeted Therapy of Triple-Negative Breast Cancer

Cancer is the second leading cause of death worldwide; therefore, there is an urgent need to find safe and effective therapies. Triple-negative breast cancer (TNBC) is diagnosed in ca. 15–20% of BC and is extremely aggressive resulting in reduced survival rate, which is mainly due to the low therapeutic efficacy of available treatments. Photodynamic therapy (PDT) is an interesting therapeutic approach in the treatment of cancer; the photosensitizers with good absorption in the therapeutic window, combined with their specific targeting of cancer cells, have received particular interest. This review aims to revisit the latest developments on chlorin-based photoactive molecules for targeted therapy in TNBC. Photodynamic therapy, alone or combined with other therapies (such as chemotherapy or photothermal therapy), has potential to be a safe and a promising approach against TNBC.     

Exploring the Potential of Metallodrugs as Chemotherapeutics for Triple Negative Breast Cancer

This review focuses on studies of coordination and organometallic compounds as potential chemotherapeutics against triple negative breast cancer (TNBC) which has one of the poorest prognoses and worst survival rates from all breast cancer types. At present, chemotherapy is still the standard of care for TNBC since only one type of targeted therapy has been recently developed. References for metal-based compounds studied in TNBC cell lines will be listed, and those of metal-specific reviews, but a detailed overview will also be provided on compounds studied in vivo (mostly in mice models) and those compounds for which some preliminary mechanistic data was obtained (in TNBC cell lines and tumors) and/or for which bioactive ligands have been used. The main goal of this review is to highlight the most promising metal-based compounds with potential as chemotherapeutic agents in TNBC.     

Mesoporous silica nanoparticles for 19F magnetic resonance imaging,fluorescence imaging,and drug delivery

Multifunctional mesoporous silica nanoparticles (MSNs) are good candidates for multimodal applications in drug delivery, bioimaging, and cell targeting. In particular, controlled release of drugs from MSN pores constitutes one of the superior features of MSNs. In this study, a novel drug delivery carrier based on MSNs, which encapsulated highly sensitive ¹⁹F magnetic resonance imaging (MRI) contrast agents inside MSNs, was developed. The nanoparticles were labeled with fluorescent dyes and functionalized with small molecule-based ligands for active targeting. This drug delivery system facilitated the monitoring of the biodistribution of the drug carrier by dual modal imaging (NIR/¹⁹F MRI). Furthermore, we demonstrated targeted drug delivery and cellular imaging by the conjugation of nanoparticles with folic acid. An anticancer drug (doxorubicin, DOX) was loaded in the pores of folate-functionalized MSNs for intracellular drug delivery. The release rates of DOX from the nanoparticles increased under acidic conditions, and were favorable for controlled drug release to cancer cells. Our results suggested that MSNs may serve as promising ¹⁹F MRI-traceable drug carriers for application in cancer therapy and bio-imaging.     

Chitosan‐Capped Mesoporous Silica Nanoparticles as pH‐Responsive Nanocarriers for Controlled Drug Release

Herein, we present a straightforward synthesis of pH‐responsive chitosan‐capped mesoporous silica nanoparticles (MSNs). These MCM‐41‐type MSNs could be used as nanocapsules to accommodate guest molecules. Subsequently, (3‐glycidyloxypropyl)trimethoxysilane was grafted onto the surface of the MSNs, which served as a bridge to link between MSNs and chitosan, which is ubiquitous in nature and commercially available. Owing to the pH‐responsive and biocompatible features of chitosan, the loading and release of an anti‐cancer drug, doxorubicin hydrochloride, were carried out in vitro, in which the composite chitosan‐capped MSNs (CS‐MSNs) showed excellent environmental response. As the pH value of the media decreased, the degree of drug release correspondingly increased. Moreover, thanks to the perfect biocompatibility of chitosan, the CS‐MSNs exhibited lower cytotoxicity than that of the naked MSNs in an MTT assay. In addition, the in vitro kill potency against MCF‐7 breast‐cancer cells was enhanced over time, as well as with increasing concentration of the drug‐loaded CS‐MSNs. These results indicate that CS‐MSNs are promising candidates for pH‐responsive drug delivery in cancer therapy.     

Tumour‐Targeted Drug Delivery with Mannose‐Functionalized Nanoparticles Self‐Assembled from Amphiphilic β‐Cyclodextrins

Multivalent mannose‐functionalized nanoparticles self‐assembled from amphiphilic β‐cyclodextrins (β‐CDs) facilitate the targeted delivery of anticancer drugs to specific cancer cells. Doxorubicin (DOX)‐loaded nanoparticles equipped with multivalent mannose target units were efficiently taken up via receptor‐mediated endocytosis by MDA‐MB‐231 breast cancer cells that overexpress the mannose receptor. Upon entering the cell, the intracellular pH causes the release of DOX, which triggers apoptosis. Targeting by multivalent mannose significantly improved the capability of DOX‐loaded nanoparticles to inhibit the growth of MDA‐MB‐231 cancer cells with minimal side effects in vivo. This targeted and controlled drug delivery system holds promise as a nanotherapeutic for cancer treatment.     

Degradation of HER2 Receptor Through Hypericin-mediated Photodynamic Therapy

Current treatment of breast cancer is often affected by resistance to therapeutics, for which the human epidermal growth factor receptor 2 (HER2) may be responsible. Here, we report for the first time the use of hypericin-mediated photodynamic therapy (HY-PDT) in combination with a selective HER2 inhibitor (AG 825) on SKBR-3, a HER2 overexpressing human breast adenocarcinoma cell line. The results demonstrate that HY-PDT is able to degrade HER2 with an impact on its signaling cascade. Combination with AG 825 resulted in increased apoptosis induction, total degradation of HER2 and inhibition of colony formation. Downregulation of HSP90, Mcl-1, Bcl-xL and upregulation of Bax was also observed. This knowledge provides the basis for the possible application of HY-PDT in preclinical and clinical models of breast cancer treatment.     

Intracellular Uptake of PEG-Funtionalized Baicalein Loaded Iron Oxide Nanoparticles Regulates Apoptotic Genes in Triple Negative Breast Cancer Cells: Mitochondrial Pathway Targeted Therapy for Breast Cancer

The recent focus and development of nanotechnology in medicine is countless, which involves diagnostic, therapeutic and preventive systems for various diseases. Nanoparticles have received much attention due to their uses in cancer therapy. The current study focused on the synthesis of baicalein loaded iron oxide nanoparticles and their efficacy against triple negative breast cancer (TNBC) MDA-MB-231. The electron microscopic analysis reveals that the particles were internalized with the various sub cellular regions of selected cancer cells. Further flow cytometric analysis of mitochondrial membrane potential using JC-1 staining showed that significant aggregates were found in the cells treated with baicalein loaded iron oxide nanoparticles, which, in turn, implies momentous mitochondrial membrane potential loss that occurs. Similarly apoptotic and anti-apoptotic gene expression pattern showed that baicalein loaded iron oxide nanoparticles were upregulates the apoptotic genes like Bad, Bax, GADD45 and PARP cleavage in a dose dependant manner. Detailed kit based flowcytometric analysis also reveals that the above findings were significant in the focused field, it is apparent that nano conjugates have the ability to induce apoptosis, DNA damage and cell cycle arrest and decrease the rate of cell proliferation in TNBC cells.     

Differential Effects of Polymer‐Surface Decoration on Drug Delivery,Cellular Retention,and Action Mechanisms of Functionalized Mesoporous Silica Nanoparticles

Polymer‐surface decoration has been found to be an effective strategy to enhance the biological activities of nanomedicine. Herein, three different types of polymers with a cancer‐targeting ligand Arg‐Gly‐Asp peptide (RGD) have been used to decorate mesoporous silica nanoparticles (MSNs) and the functionalized nanosystems were used as drug carriers of oxaliplatin (OXA). The results showed that polymer‐surface decoration of the MSNs nanosystem by poly(ethylene glycol) (PEG) and polyethyleneimine (PEI) significantly enhanced the anticancer efficacy of OXA, which was much higher than that of chitosan (CTS). This effect was closely related to the enhancement of the cellular uptake and cellular drug retention. Moreover, PEI@MSNs‐OXA possessed excellent advantages in penetrating ability and inhibitory effects on SW480 spheroids that were used to simulate the in vivo tumor environments. Therefore, this study provides useful information for the rational design of a cancer‐targeted MSNs nanosystem with polymer‐surface decoration.     

Concept Design,Development and Preliminary Physical and Chemical Characterization of Tamoxifen-Guided-Mesoporous Silica Nanoparticles

Conventional chemotherapies used for breast cancer (BC) treatment are non-selective, attacking both healthy and cancerous cells. Therefore, new technologies that enhance drug efficacy and ameliorate the off-target toxic effects exhibited by currently used anticancer drugs are urgently needed. Here we report the design and synthesis of novel mesoporous silica nanoparticles (MSNs) equipped with the hormonal drug tamoxifen (TAM) to facilitate guidance towards estrogen receptors (ERs) which are upregulated in breast tumours. TAM is linked to the MSNs using a poly-ʟ-histidine (PLH) polymer as a pH-sensitive gatekeeper, to ensure efficient delivery of encapsulated materials within the pores. XRD, HR-TEM, DLS, SEM, FT-IR and BET techniques were used to confirm the successful fabrication of MSNs. The MSNs have a high surface area (>1000 m²/g); and a mean particle size of 150 nm, which is an appropriate size to allow the penetration of premature blood vessels surrounding breast tumours. Successful surface functionalization was supported by FT-IR, XPS and TGA techniques, with a grafting ratio of approximately 29%. The outcomes of this preliminary work could be used as practical building blocks towards future formulations.     

Graphene nanoribbon-based supramolecular ensembles with dual-receptor targeting function for targeted photothermal tumor therapy

Triple negative breast cancer (TNBC) is one of the most malignant subtypes of breast cancer. Here, we report the construction of graphene nanoribbon (GNR)-based supramolecular ensembles with dual-receptor (mannose and α_vβ₃ integrin receptors) targeting function, denoted as GNR-Man/PRGD, for targeted photothermal treatment (PTT) of TNBC. The GNR-Man/PRGD ensembles were constructed through the solution-based self-assembly of mannose-grafted GNRs (GNR-Man) with a pyrene-tagged α_vβ₃ integrin ligand (PRGD). Enhanced PTT efficacies were achieved both in vitro and in vivo compared to that of the non-targeting equivalents. Tumor-bearing live mice were administered (tail vein) with GNR-Man/PRGD and then each mice group was subjected to PTT. Remarkably, GNR-Man/PRGD induced complete ablation of the solid tumors, and no tumor regrowth was observed over a period of 15 days. This study demonstrates a new and promising platform for the development of photothermal nanomaterials for targeted tumor therapy.

Dual receptor-targeting supramolecular glycomaterials are constructed based on graphene nanoribbons for the targeted photothermal therapy of triple-negative breast cancer in vivo.     

Entelon® (Vitis vinifera Seed Extract) Prevents Cancer Metastasis via the Downregulation of Interleukin-1 Alpha in Triple-Negative Breast Cancer Cells

Interleukin-1 (IL1) is a proinflammatory cytokine and promotes cancer cell proliferation and invasiveness in a diversity of cancers, such as breast and colon cancer. Here, we focused on the pharmacological effect of Entelon^® (ETL) on the tumorigenesis of triple-negative breast cancer (TNBC) cells by IL1-alpha (IL1A). IL1A enhanced the cell growth and invasiveness of TNBC cells. We observed that abnormal IL1A induction is related with the poor prognosis of TNBC patients. IL1A also increased a variety of chemokines such as CCL2 and IL8. Interestingly, IL1A expression was reduced by the ETL treatment. Here, we found that ETL significantly decreased the MEK/ERK signaling pathway in TNBC cells. IL1A expression was reduced by UO126. Lastly, we studied the effect of ETL on the metastatic potential of TNBC cells. Our results showed that ETL significantly reduced the lung metastasis of TNBC cells. Our results showed that IL1A expression was regulated by the MEK/ERK- and PI3K/AKT-dependent pathway. Taken together, ETL inhibited the MEK/ERK and PI3K/AKT signaling pathway and suppressing the lung metastasis of TNBC cells through downregulation of IL1A. Therefore, we propose the possibility of ETL as an effective adjuvant for treating TNBC.     

Quantitative Proteomic Studies on TNBC in Premenopausal Patients

The molecular mechanism of triple-negative breast cancer(TNBC) remains unclear, and there has been no effective targeted therapy for it. A better understanding of the mechanisms of TNBC is urgently needed to identify new therapeutic targets. In this study, eight cases of premenopausal TNBC patients were collected, and a comparative proteomic analysis of their breast cancer tissues and matched paraneoplastic ones was performed via isobaric tags for relative and absolute quantitation(iTRAQ) technology coupled with two-dimensional liquid chromatography-tandem mass spectrumetry(2D LC-MS/MS). The researches result in the identification of 1254 nonredundant proteins, of which 1243 proteins reached the strict quantitative standard. The quantitative comparison reveal that among the 214 proteins, 81 proteins significantly increased and 133 proteins decreased in TNBC tissues compared to corresponding ones in control. The Gene Ontology(GO) annotations and pathway analysis show their distributions in GO and the marked functions, as well as the closely related signal transduction pathways involved in extra cellular matrix (ECM)-receptor interaction, protein digestion and absorption, renin-angiotensin system, complement and coagulation cascades and focal adhesion. This pilot study will lay a foundation for further searching for therapeutic targets of TNBC and exploring the molecular mechanism, which can also be extended as a part of a large scale biomarker discovery plan.