PKD2 mediates multi-drug resistance in breast cancer cells through modulation of P-glycoprotein expression

Combination therapy of Lapatinib/Letrozole-based protein-vitamin nanoparticles to enhance the therapeutic effectiveness in drug-resistant breast cancer

HER2-positive breast cancer constitutes 20 % of reported cases, characterized by excessive expression of HER2 receptors, pivotal in cell signaling and growth. Immunotherapy, the established treatment, often leads to multidrug resistance and tumor recurrence. There's a critical need for an effective strategy delaying drug resistance onset and ensuring cancer cell eradication. This study aimed to develop nanoparticles using human serum albumin (HSA) coupled with vitamin E (α-tocopherol succinate), loaded with a tyrosine kinase inhibitor (TKI) or aromatase inhibitor (AI). Nanoparticles were formed via desolvation, where HSA(VE) conjugates self-organized into a nanoparticle structure, incorporating TKI/AI either through chemical conjugation or direct binding to HSA. Physico-chemical analyses-such as infrared spectroscopy (IR), gel permeation chromatography (GPC), UV, IR, and CD spectroscopy confirmed HSA(VE) binding and drug incorporation into nanoparticles, evaluating their drug entrapment, release efficiency. Cell viability assays and in-vitro experiments on resistant and sensitive cell lines demonstrated effective drug encapsulation and absorption over time. Both in vitro and in vivo studies demonstrated that a combination of Lapa@HSA(VE) NPs and Let@HSA(VE) NPs in the ratio 75:25 inhibited tumor development and enhanced apoptosis significantly compared to individual NP treatment and free drug. The combination NPs therapy exhibited significant efficacy even in Lapa-resistant cell lines.

Biotin-Pt(IV)-Ru(II)-Boron-Dipyrromethene Prodrug as "Platin Bullet" for Targeted Chemo- and Photodynamic Therapy

Using the principle of "Magic Bullet", a cisplatin-derived platinum(IV) prodrug heterobimetallic Pt(IV)-Ru(II) complex, cis,cis,trans-[Pt(NH3)2Cl2{Ru(tpy-BODIPY)(tpy-COO)}(biotin)]Cl2 (Pt-Ru-B, 2), having two axial ligands, namely, biotin as water-soluble B-vitamin for enhanced cellular uptake and a BODIPY-ruthenium(II) (Ru-B, 1) photosensitizer having N,N,N-donor tpy (4'-phenyl-2,2':6',2″-terpyridine) bonded to boron-dipyrromethene (BODIPY), is developed as a "Platin Bullet" for targeted photodynamic therapy (PDT). Pt-Ru-B exhibited intense absorption near 500 nm and emission near 513 nm (λex = 488 nm) in a 10% dimethyl sulfoxide-Dulbecco's phosphate-buffered saline medium (pH 7.2). The BODIPY complex on light activation generates singlet oxygen as the reactive oxygen species (ROS) giving a quantum yield (ΦΔ) of ∼0.64 from 1,3-diphenylisobenzofuran experiments. Pt-Ru-B exhibited preferential cellular uptake in cancer cells over noncancerous cells. The dichlorodihydrofluorescein diacetate assay confirmed the generation of cellular ROS. Confocal images revealed its mitochondrial internalization. Pt-Ru-B showed submicromolar photocytotoxicity in visible light (400-700 nm) in A549 and multidrug-resistant MDA-MB-231 cancer cells. It remained nontoxic in the dark and less toxic in nontumorigenic cells. Cellular apoptosis and alteration of the mitochondrial membrane potential were evidenced from the respective Annexin V-FITC/propidium iodide assay and JC-1 dye assay. A wound healing assay using A549 cells and Pt-Ru-B revealed inhibition of cancer cell migration, highlighting its potential as an antimetastatic agent.

Impact of Chemotherapeutic Stress Depends on The Nature of Breast Cancer Spheroid and Induce Behavioral Plasticity to Resistant Population

Cellular or tumor dormancy, identified recently as one of the main reasons behind post-therapy recurrence, can be caused by diverse reasons. Chemotherapy has recently been recognized as one of such reasons. However, in-depth studies of chemotherapy-induced dormancy are lacking due to the absence of an in vitro human-relevant model tailor-made for such a scenario. This report utilized multicellular breast cancer spheroid to create a primary platform for establishing a chemotherapy-induced dormancy model. It is observed that extreme chemotherapeutic stress affects invasive and non-invasive spheroids differently. Non-invasive spheroids exhibit more resilience and maintain viability and migrational ability, while invasive spheroids display heightened susceptibility and improved tumorigenic capacity. Heterogenous spheroids exhibit increased tumorigenic capacity while show minimal survival ability. Further probing of chemotherapeutically dormant spheroids is needed to understand the molecular mechanism and identify dormancy-related markers to achieve therapeutic success in the future.

Protein kinase D drives the secretion of invasion mediators in triple-negative breast cancer cell lines

The protein kinase D (PKD) family members regulate the fission of cargo vesicles at the Golgi complex and play a pro-oncogenic role in triple-negative breast cancer (TNBC). Whether PKD facilitates the secretion of tumor-promoting factors in TNBC, however, is still unknown. Using the pharmacological inhibition of PKD activity and siRNA-mediated depletion of PKD2 and PKD3, we identified the PKD-dependent secretome of the TNBC cell lines MDA-MB-231 and MDA-MB-468. Mass spectrometry-based proteomics and antibody-based assays revealed a significant downregulation of extracellular matrix related proteins and pro-invasive factors such as LIF, MMP-1, MMP-13, IL-11, M-CSF and GM-CSF in PKD-perturbed cells. Notably, secretion of these proteins in MDA-MB-231 cells was predominantly controlled by PKD2 and enhanced spheroid invasion. Consistently, PKD-dependent secretion of pro-invasive factors was more pronounced in metastatic TNBC cell lines. Our study thus uncovers a novel role of PKD2 in releasing a pro-invasive secretome.

Lupeol synergizes with 5-fluorouracil to combat c-MET/EphA2 mediated chemoresistance in triple negative breast cancer

Triple-negative breast cancer (TNBC) is the most elusive subtype of breast cancer that encounters treatment dilemmas owing to the paucity of druggable targets. We found hyperactivation of c-MET and ephrin type-A receptor 2 (EphA2) in patients treated with 5FU driven chemotherapy which correlated with lower disease-free survival. However, silencing of both these genes resulted in a marked decrease in the invasive, migratory, and tumorigenic potential of TNBC cells, indicating that a dual target strategy is actionable. Lupeol is a phytochemical, with potent anticancer efficacy and minimal side effects in preclinical studies. A synergistic strategy with 5FU and Lupeol elicited promising anticancer responses in vitro, in vivo, and in patient-derived ex vivo tumor culture models. This synergistic regimen is effective, even in the presence of HGF, which mechanistically orchestrates the activation of c-MET and EphA2. These data lay the foundation for the clinical validation of this combination therapy for TNBC patients.

Biotin and boron-dipyrromethene-tagged platinum(IV) prodrug for cellular imaging and mito-targeted photocytotoxicity in red light

A platinum(IV) prodrug, cis,cis,trans-[Pt(NH3)2Cl2(biotin)(L)] (1), derived from cisplatin, where HL is the PEGylated red-light active boron-dipyrromethene (BODIPY) ligand, was synthesized, characterized and its photocytotoxicity evaluated. The complex showed a near-IR absorption band at 653 nm (ε ∼9.19 × 104 M-1 cm-1) in dimethyl sulfoxide and Dulbecco's phosphate-buffered saline (1 : 1 v/v) at pH 7.2. When excited at 630 nm, it showed an emission band at 677 nm in DMSO with a fluorescence quantum yield of 0.13. The 1,3-diphenylisobenzofuran titration experiment gave a singlet oxygen quantum yield (ΦΔ) of ∼0.32. A mechanistic DNA photocleavage study revealed singlet oxygen as the reactive oxygen species (ROS). The complex with biotin and PEGylated-distyryl-BODIPY showed significantly higher cellular uptake in A549 cancer cells as compared to non-cancerous Beas-2B cells from flow cytometry, indicating selectivity towards cancer cells. A dichlorodihydrofluorescein diacetate assay showed cellular ROS generation. Confocal images revealed predominant internalization in the mitochondria. The prodrug showed remarkable photodynamic therapy (PDT) activity in cancerous A549 and multidrug-resistant MDA-MB-231 cells with a high photocytotoxicity index value (half-maximal inhibitory concentration (IC50): 0.61-1.54 μM in red light), while being non-toxic in the dark. The chemo-PDT activity was significantly less in non-tumorigenic lung epithelial cells (Beas-2B). The prodrug effectively triggered cellular apoptosis, which was confirmed by the Annexin V-FITC/propidium iodide assay, and the alteration of the mitochondrial membrane potential was substantiated by the JC-1 dye assay. The β-tubulin immunofluorescence assay confirmed that incubating the cells with a light-treated complex resulted in the rapture of the cytoskeletal structure and the formation of apoptotic bodies. The results demonstrate that the prodrug triggered apoptosis via DNA damage, a reduction in mitochondrial function and disruption of the cytoskeletal framework.

Combined dandelion extract and all-trans retinoic acid induces cytotoxicity in human breast cancer cells

Breast cancer is one of the most prevalent and deadly cancers among women worldwide. Recently, natural compounds have been widely used for the treatment of breast cancer. Present study evaluated antiproliferative and anti-metastasis activities of two natural compounds of dandelion and all-trans-retinoic acid (ATRA) in human MCF-7 and MDA-MB231 breast cancer cells. We also evaluated the expression of MMP-2, MMP-9, IL-1β, p53, NM23 and KAI1 genes. Data showed a clear additive cytotoxic effect in concentrations of 40 μM ATRA with 1.5 and 4 mg/ml of dandelion extract in MCF-7 and MDA-MB231 cells, respectively. In both cell lines, compared with the untreated cells, the expression levels of MMP-9 and IL-1β were significantly decreased while p53 and KAI1 expression levels were increased. Besides, MMP-2 and NM23 had different expressions in the two studied cell lines. In conclusion, dandelion/ATRA co-treatment, in addition to having strong cytotoxic effects, has putative effects on the expression of anti-metastatic genes in both breast cancer cells.

Mesoporous Polydopamine-Encapsulated Fluorescent Nanodiamonds: A Versatile Platform for Biomedical Applications

Fluorescent nanodiamonds (FNDs) are versatile nanomaterials with promising properties. However, efficient functionalization of FNDs for biomedical applications remains challenging. In this study, we demonstrate mesoporous polydopamine (mPDA) encapsulation of FNDs. The mPDA shell is generated by sequential formation of micelles via self-assembly of Pluronic F127 (F127) with 1,3,5-trimethyl benzene (TMB) and composite micelles via oxidation and self-polymerization of dopamine hydrochloride (DA). The surface of the mPDA shell can be readily functionalized with thiol-terminated methoxy polyethylene glycol (mPEG-SH), hyperbranched polyglycerol (HPG), and d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS). The PEGylated FND@mPDA particles are efficiently taken up by, and employed as a fluorescent imaging probe for, HeLa cells. HPG-functionalized FND@mPDA is conjugated with an amino-terminated oligonucleotide to detect microRNA via hybridization. Finally, the increased surface area of the mPDA shell permits efficient loading of doxorubicin hydrochloride. Further modification with TPGS increases drug delivery efficiency, resulting in high toxicity to cancer cells.

Membrane trafficking in breast cancer progression: protein kinase D comes into play

Protein kinase D (PKD) is a serine/threonine kinase family that controls important cellular functions, most notably playing a key role in the secretory pathway at the trans-Golgi network. Aberrant expression of PKD isoforms has been found mainly in breast cancer, where it promotes various cellular processes such as growth, invasion, survival and stem cell maintenance. In this review, we discuss the isoform-specific functions of PKD in breast cancer progression, with a particular focus on how the PKD controlled cellular processes might be linked to deregulated membrane trafficking and secretion. We further highlight the challenges of a therapeutic approach targeting PKD to prevent breast cancer progression.

Anticancer Activity of Nano-formulated Orlistat-Dopamine Conjugates Through Self-Assembly

Orlistat, an FDA-approved fatty acid inhibitor for obesity treatment, demonstrates certain low and greatly varied anticancer abilities. In a previous study, we revealed a synergistic effect between orlistat and dopamine in cancer treatment. Here, orlistat-dopamine conjugates (ODCs) with defined chemical structures were synthesized. The ODC by design underwent polymerization and self-assembly in the presence of oxygen to form nano-sized particles (Nano-ODCs) spontaneously. The resulted Nano-ODCs of partial crystalline structures demonstrated good water dispersion to form stable Nano-ODC suspensions. Because of the bioadhesive property of the catechol moieties, once administered, Nano-ODCs were quickly accumulated on cell surfaces and efficiently uptaken by cancer cells. In the cytoplasm, Nano-ODC experienced biphasic dissolution followed by spontaneous hydrolysis to release intact orlistat and dopamine. Besides elevated levels of intracellular reactive oxygen species (ROS), the co-localized dopamine also induced mitochondrial dysfunctions through monoamine oxidases (MAOs)-catalyzed dopamine oxidation. The strong synergistic effects between orlistat and dopamine determined a good cytotoxicity activity and a unique cell lysis mechanism, explaining the distinguished activity of Nano-ODC to drug-sensitive and -resistant cancer cells. This new technology-enabled orlistat repurposing will contribute to overcoming drug resistance and the improvement of cancer chemotherapy.

Shenqi Fuzheng injection reverses M2 macrophage-mediated cisplatin resistance through the PI3K pathway in breast cancer

BACKGROUND

Shenqi Fuzheng injection (SQFZ) combined with chemotherapy can sensitize tumour cells. However, the mechanisms underlying SQFZ's effects remain unknown. In human breast cancer cell lines and M2 macrophages, we showed that SQFZ was a significantly potent agent of sensitization.

METHODS

The human breast cancer cell line, MDA-MB-231/DDP, and the human acute leukaemia mononuclear cell line, THP-1, were used. MDA-MB-231/DDP breast cancer xenografts were established to monitor tumour growth. Resistance-associated proteins were examined by western blotting. Levels of cytokines and chemokines were detected by ELISA. Cell viability was measured using the MTT assay. Apoptosis was detected by flow cytometric analysis.

RESULTS

SQFZ significantly enhanced the capability of cisplatin to reduce tumour mass. SQFZ and cisplatin decreased the expression of CD206 by 1.89-fold and increased that of CD86 by 1.76-fold as compared to cisplatin alone. The levels of PGE2, IL-6, and CCL1 decreased significantly, and the activation of p-PI3K and the expressions of P-gp and ABCG2 were also inhibited by SQFZ in combination with cisplatin treatment in vivo. The survival following cisplatin administration of 60 μM and 120 μM reduced significantly in the presence of SQFZ in MDA-MB-231/DDP and M2 co-cultured cells. IGF-1, a PI3K activator, combined with SQFZ weakened the effects of SQFZ-induced apoptosis from 28.7% to 10.5%. The effects of IGF-1 on increasing the expressions of P-gp, ABCG2, and Bcl-2, and decreasing that of Bax were reversed by SQFZ.

CONCLUSION

Our findings provide evidence that SQFZ is a potential therapeutic drug for cancer therapy.

Development of 1,3-diynyl derivatives of noscapine as potent tubulin binding anticancer agents for the management of breast cancer

We developed 1,3-diynyl derivatives of noscapine (an opium alkaloid) through in silico combinatorial approach and screened out a panel of promising derivatives that bind tubulin and display anticancer activity. The selected derivatives such as 9-4-^tBu-Ph-Diyne (20p), 9-3,4-Di-Cl-Diyne (20k) and 9-3,4-Di-F-Diyne (22s) noscapinoids revealed improved predicted binding energy of -6.676 kcal/mol for 20p, -7.294 kcal/mol for 20k and -7.750 kcal/mol for 20s respectively in comparison to noscapine (-5.246 kcal/mol). These 1,3-diynyl derivatives (20p, 29k and 20s) were strategically synthesized in high yields by regioselective modification of noscapine scaffold and HPLC purified (purity is >96%). The decrease in intrinsic fluorescence of purified tubulin to 8.39%, 17.39% and 25.47% by 20p, 20k and 20s respectively, compared to control suggests their binding capability to tubulin. Their cytotoxicity activity was validated based on cellular studies using two human breast adenocarcinoma (MCF-7 and MDA-MB-231), a panel of primary breast tumor cells and one normal human embryonic kidney cell (293 T). The 1,3-diynyl noscapinoids, 20p, 20k and 20s inhibited cellular proliferation in all the cancer cells that ranged between 6.2 and 38.9 µM, without affecting the normal healthy cells (cytotoxicity is <5% at 100 µM). Further, these novel derivatives arrest cell cycle in the G2/M-phase, followed by induction of apoptosis to cancer cells. Thus, we conclude that 1,3-diynyl-noscapinoids have great potential to be a novel therapeutic agent for breast cancers.Communicated by Ramaswamy H. Sarma.

Low Sulfur Amino Acid, High Polyunsaturated Fatty Acid Diet Inhibits Breast Cancer Growth

Cancer cells may acquire resistance to stress signals and reprogram metabolism to meet the energetic demands to support their high proliferation rate and avoid death. Hence, targeting nutrient dependencies of cancer cells has been suggested as a promising anti-cancer strategy. We explored the possibility of killing breast cancer (BC) cells by modifying nutrient availability. We used in vitro models of BC (MCF7 and MDA-MB-231) that were maintained with a low amount of sulfur amino acids (SAAs) and a high amount of oxidizable polyunsatured fatty acids (PUFAs). Treatment with anti-apoptotic, anti-ferroptotic and antioxidant drugs were used to determine the modality of cell death. We reproduced these conditions in vivo by feeding BC-bearing mice with a diet poor in proteins and SAAs and rich in PUFAs (LSAA/HPUFA). Western blot analysis, qPCR and histological analyses were used to assess the anti-cancer effects and the molecular pathways involved. We found that BC cells underwent oxidative damage to DNA and proteins and both apoptosis and ferroptosis were induced. Along with caspases-mediated PARP1 cleavage, we found a lowering of the GSH-GPX4 system and an increase of lipid peroxides. A LSAA/HPUFA diet reduced tumor mass and its vascularization and immune cell infiltration, and induced apoptosis and ferroptotic hallmarks. Furthermore, mitochondrial mass was found to be increased, and the buffering of mitochondrial reactive oxygen species limited GPX4 reduction and DNA damage. Our results suggest that administration of custom diets, targeting the dependency of cancer cells on certain nutrients, can represent a promising complementary option for anti-cancer therapy.

Phosphatidylcholine-Based Nanoemulsions for Paclitaxel and a P-Glycoprotein Inhibitor Delivery and Breast Cancer Intraductal Treatment

In this study, incorporation of the cytotoxic agent paclitaxel and the P-glycoprotein inhibitor elacridar in hyaluronic acid (HA)-modified nanoemulsions was studied for intraductal delivery and breast cancer localized treatment. To improve cytotoxicity, we investigated the incorporation of perillyl alcohol or tributyrin as components of the nanoemulsion oil phase. The nanoemulsions presented size <180 nm and negative zeta potential. Both tributyrin and perillyl alcohol increased nanoemulsion cytotoxicity in MCF-7 cells, but not in MDA-MB-231. However, perillyl alcohol reduced nanoemulsion stability in the presence of the drugs. Concomitant incorporation of paclitaxel and elacridar in HA- and tributyrin-containing nanoemulsions (PE-NETri) increased cytotoxicity and reduced IC50 by 1.6 to 3-fold in MCF-7 and MDA-MB-231 cells compared to the nanoemulsion containing only paclitaxel (P-NE). This nanoemulsion also produced a 3.3-fold reduction in the viability of MDA-MB-231 spheroids. Elacridar incorporated in the nanoemulsion was capable of inhibiting P-glycoprotein in membranes. In vivo intraductal administration of the NE containing HA resulted in a three-fold higher retention of a fluorescent marker compared to a solution or nanoemulsion without HA, demonstrating the importance of HA. The nanoemulsion produced no histological changes in the mammary tissue. These results support the potential applicability of the nanoemulsion for local breast cancer management.

Peptide-functionalised magnetic silk nanoparticles produced by a swirl mixer for enhanced anticancer activity of ASC-J9

Silk fibroin is an FDA approved biopolymer for clinical applications with great potential in nanomedicine. However, silk-based nanoformulations are still facing several challenges in processing and drug delivery efficiency (such as reproducibility and targetability), especially in cancer therapy. To address these challenges, robust and controllable production methods are required for generating nanocarriers with desired properties. This study aimed to develop a novel method for the production of peptide-functionalized magnetic silk nanoparticles with higher selectivity for cancer cells for targeted delivery of the hydrophobic anticancer agent ASC-J9. A new microfluidic device with a swirl mixer was designed to fabricate magnetic silk nanoparticles (MSNP) with desired size and narrow size distribution. The surface of MSNPs was functionalized with a cationic amphiphilic anticancer peptide, G(IIKK)3I-NH2 (G3), to enhance their selectivity towards cancer cells. The G3-MSNPs increased the cellular uptake and anticancer activity of G3 in HCT 116 colorectal cancer cells compared to free G3. Moreover, the G3-MSNPs exhibited considerably higher cellular uptake and cytotoxicity in HCT 116 colorectal cancer cells compared to normal cells (HDFs). Encapsulating ASC-J9 in G3-MSNPs resulted in augmented anticancer activity compared to free ASC-J9 and non-functionalized ASC-J9 loaded MSNPs within its biological half-life. Hence, functionalizing MSNPs with G3 enabled targeted delivery of ASC-J9 to cancer cells and enhanced its anticancer effect. Functionalization of nanoparticles with anticancer peptides could be regarded as a new strategy for targeted delivery and enhanced efficiency of anticancer drugs. Furthermore, the microfluidic device introduced in this paper offers a robust and reproducible method for fabrication of small sized homogenous nanoparticles.

Immunohistochemical expression of PD-L1 and MDR1 in breast tumors: association with clinico-pathological parameters and treatment outcome

Antitumor immune evasion is a hallmark for the development and progression of cancer. Tumor cells adopt various mechanisms to escape the host immune system recognition. One such mechanism is the over expression of programmed death ligand (PD-L1), a negative T cell regulatory molecule. Because PD-L1 overexpression causes resistance to chemotherapeutic response in many cancers, herein we explored the relationship between PD-L1 and multidrug resistance protein MDR1 in breast cancer. Immunohistochemical evaluation of PD-L1 and MDR1 proteins in 194 breast cancer tissue samples were carried out. The relationship between PD-L1 and MDR1 expression on cancer cells with clinicopathological factors and prognosis was investigated. IHC showed a significant correlation between PD-L1 and MDR1 expression on tumor cells. Increased PD-L1 expression was also associated with lymph node status and tumor grade of the patient. Our results also revealed that the expression of PD-L1 and MDR1 was higher in TNBC subtype compared to other breast cancer subtypes. Therefore, a better understanding of the molecular mechanism through which PD-1/PD-L1 pathway contribute to the chemoresistance might bring forth the prognostic significance of PD-L1 and selection of patients who may benefit from immunotherapy.

The potential roles of retinoids in combating drug resistance in cancer: implications of ATP-binding cassette (ABC) transporters

Multidrug resistance (MDR) means that tumour cells become unresponsive during or after the course of treatment to one or more of chemotherapeutic drugs. Chemotherapeutic resistance critically limits the treatment outcomes and remains a key challenge for clinicians. The alternation in intracellular drug concentration through the modulation of its transport across the plasma membrane is the major cause for MDR and is adopted by various mediators, including ATP-requiring enzymes (ATPases). Among these ATPases, ABC transporters have been extensively studied, and found to be highly implicated in tumorigenesis and MDR. The present review sheds light on the documented effects of retinoids on ABC enzymes to understand their mechanism in combating cancer cell resistance. This would open the gate to test the mechanism and applicability of different new synthetic retinoids in literature and market as modulators of ATP-dependent efflux pumping activity, and promote their applicability in diminishing anti-cancer drug resistance.

BODIPY-Tagged Platinum(II) Curcumin Complexes for Endoplasmic Reticulum-Targeted Red Light PDT

[Pt(RB)(Cur)]NO₃ (RBC), [Pt(IRB)(Cur)]NO₃ (IRBC), and [Pt(L)(Cur)]NO₃ (PBC), where HCur is curcumin, L is 1-benzyl-2-(2-pyridyl)benzimidazole, and RB and IRB are red-light-active non-iodo and diiodo-BODIPY tagged to L, respectively, were synthesized and characterized, and their anticancer activities were studied (BODIPY, boron-dipyrromethene). RBC and IRBC displayed BODIPY-centered absorption bands within 615-635 nm along with the respective curcumin bands at 445 and 492 nm in 10% dimethyl sulfoxide (DMSO)-Dulbecco's phosphate-buffered saline (DPBS). Emission bands were observed at 723 and 845 nm for RBC and IRBC, respectively, in 10% DMSO-DPBS. RBC (Φ_Δ, 0.27) and IRBC (Φ_Δ, 0.40) generated singlet oxygen in red light (λ = 642 nm) as evidenced from 1,3-diphenylisobenzofuran (DPBF) titrations. The formation of ¹O₂ from BODIPY and HO^• from the curcumin was evidenced from the mechanistic pUC19 DNA photocleavage studies. The BODIPY complexes showed photocytotoxicity in A549, HeLa, and MDA-MB-231 cells while being less toxic in the dark [IC₅₀: 1.3-6.9 μM, red light; 7.2-12.8 μM, 400-700 nm visible light]. The emissive RBC displayed localization in the endoplasmic reticulum (ER). Apoptotic cell death was evidenced from the Annexin-V/fluorescein isothiocyanate (FITC)/propidium iodide (PI) assay and green fluorescence in red light in the Fluo-4 AM assay due to ER stress, and mitochondrial dysfunction was evidenced from the 5,5,6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolylcarbocyanine iodide (JC-1) assay in A549 cells.

In Situ Programmable DNA Circuit-Promoted Electrochemical Characterization of Stemlike Phenotype in Breast Cancer

Breast cancer is one of the most common malignant diseases among women worldwide, and the existence of breast cancer stem cells is closely associated with poor outcomes. Herein, we report an electrochemical phenotyping method to characterize the stemlike phenotype in breast cancer, offering a low-cost but robust choice other than the highly expensive and experience-dependent flow cytometry. Specially, after immune-magnetic beads-assisted enrichment, an in situ programmable DNA circuit is designed using capture probes to bring in the toeholds for DNA assembly and effector probes to accelerate the removal of background signals. The electrochemical phenotyping method could sensitively determine breast cancer stem cells in a wide linear range and exhibit desirable accuracy and reliability. The method can not only monitor the phenotypic transition of breast cancer cells and the drug-reversed effect but also determinate stemlike phenotype in the mice bearing breast cancer xenograft tumor. Overall, the electrochemical phenotyping method may provide promising technical support for precise management of breast tumors.

Stiffness-tuneable nanocarriers for controlled delivery of ASC-J9 into colorectal cancer cells

HYPOTHESIS

One of the main challenges in cancer therapy is the poor water solubility of many anticancer drugs which results in low bioavailability at the tumour sites and reduced efficacy. The currently available polymer-based anticancer drug delivery systems often suffer from low encapsulation efficiency, uncontrolled release, and lack of long-term stability. Herein, we report the development of novel stiffness-tuneable core-shell nanocarriers composed of naturally derived polymers silk fibroin (SF) and sodium alginate (SA) inside a liposomal shell for enhanced cellular uptake and controlled release of hydrophobic anticancer agent ASC-J9 (Dimethylcurcumin). It is anticipated that the stiffness of the nanocarriers has a significant effect on their cellular uptake and anticancer efficacy.

EXPERIMENTS

The nanocarriers were prepared by thin film hydration method followed by extrusion and cross-linking of SA to obtain a uniform size and shape, avoiding harsh processing conditions. The structural transformation of SF in the nanocarriers induced by SA crosslinking was determined using Fourier transform infrared (FTIR) spectroscopy. The size, zeta potential, morphology and stiffness of the nanocarriers were measured using dynamic light scattering (DLS), transmission electron microscopy (TEM) and atomic force microscopy (AFM). Drug loading and release were measured using UV-Vis spectrophotometry. The cellular uptake and anticancer efficacy of the nanocarriers were studied in HCT 116 human colorectal adenocarcinoma cells and 3D tumour spheroids using high content microscopy.

FINDINGS

The synthesized nanocarriers had high encapsulation efficiency (62-78%) and were physically stable for up to 5 months at 4 ˚C. The release profile of the drug from the nanocarriers was directed by their stiffness and was easily tuneable by changing the ratio of SF to SA in the core. Furthermore, the designed nanocarriers improved the cellular uptake and anticancer activity of ASC-J9, and enhanced its tumour penetration in HCT 116 3D colorectal cancer spheroids. These findings suggest that the designed core-shell nanocarriers can be used as a highly efficient drug delivery system for cancer therapy.

Multifaceted Functions of Protein Kinase D in Pathological Processes and Human Diseases

Protein kinase D (PKD) is a family of serine/threonine protein kinases operating in the signaling network of the second messenger diacylglycerol. The three family members, PKD1, PKD2, and PKD3, are activated by a variety of extracellular stimuli and transduce cell signals affecting many aspects of basic cell functions including secretion, migration, proliferation, survival, angiogenesis, and immune response. Dysregulation of PKD in expression and activity has been detected in many human diseases. Further loss- or gain-of-function studies at cellular levels and in animal models provide strong support for crucial roles of PKD in many pathological conditions, including cancer, metabolic disorders, cardiac diseases, central nervous system disorders, inflammatory diseases, and immune dysregulation. Complexity in enzymatic regulation and function is evident as PKD isoforms may act differently in different biological systems and disease models, and understanding the molecular mechanisms underlying these differences and their biological significance in vivo is essential for the development of safer and more effective PKD-targeted therapies. In this review, to provide a global understanding of PKD function, we present an overview of the PKD family in several major human diseases with more focus on cancer-associated biological processes.

Cryopreservable arrays of paper-based 3D tumor models for high throughput drug screening

Three-dimensional (3D) tumor models have gained increased attention in life-science applications as they better represent physiological conditions of in vivo tumor microenvironments, and thus, possess big potential for guiding drug screening studies. Although various techniques proved effective in growing cancer cells in 3D, their procedures are typically complex, time consuming, and expensive. Here, we present a versatile, robust, and cost-effective method that utilizes a paper platform to create cryopreservable high throughput arrays of 3D tumor models. In the approach, we use custom 3D printed masks along with simple chemistry modifications to engineer highly localized hydrophilic 'virtual microwells', or microspots, on paper for 3D cell aggregation, surrounded by hydrophobic barriers that prevent inter-microspot mixing. The method supports the formation and cryopreservation of 3D tumor arrays for extended periods of storage time. Using MCF-7 and MDA-MB-231 breast cancer cell lines, we show that the cryopreservable arrays of paper-based 3D models are effective in studying tumor response to cisplatin drug treatment, while replicating key characteristics of the in vivo tumors that are absent in conventional 2D cultures. This technology offers a low cost, easy, and fast experimental procedure, and allows for 3D tumor arrays to be cryopreserved and thawed for on-demand use. This could potentially provide unparalleled advantages to the fields of tissue engineering and personalized medicine.

A Bio-Conjugated Chlorin-Based Metal-Organic Framework for Targeted Photodynamic Therapy of Triple Negative Breast and Pancreatic Cancers

The field of photodynamic therapy (PDT) has continued to show promise as a potential method for treating tumors. In this work a photosensitizer (PS) has been delivered to cancer cell lines for PDT by incorporation into the metal-organic framework (MOF) as an organic linker. By functionalizing the surface of MOF nanoparticles with maltotriose the PS can efficiently target cancer cells with preferential uptake into pancreatic and breast cancer cell lines. Effective targeting overcomes some current problems with PDT including long-term photosensitivity and tumor specificity. Developing a PS with optimal absorption and stability is one of the foremost challenges in PDT and the synthesis of a chlorin which is activated by long-wavelength light and is resistant to photo-bleaching is described. This chlorin-based MOF shows anti-cancer ability several times higher than that of porphyrin-based MOFs with little toxicity to normal cell lines and no dark toxicity.

The oncogenic role of protein kinase D3 in cancer

Protein kinase D3 (PRKD3), a serine/threonine kinase, belongs to protein kinase D family, which contains three members: PRKD1, PRKD2, and PRKD3. PRKD3 is activated by many stimuli including phorbol esters, and G-protein-coupled receptor agonists. PRKD3 promotes cancer cell proliferation, growth, migration, and invasion in various tumor types including colorectal, gastric, hepatic, prostate, and breast cancer. Accumulating data supports that PRKD3 is a promising therapeutic target for treatment of cancer. This review discusses the functions and mechanisms of PRKD3 in promoting tumorigenesis and tumor progression of various tumor types as well as the latest developments of small-molecule inhibitors selection for PRKD/PRKD3.

Resveratrol loaded polymeric micelles for theranostic targeting of breast cancer cells

Treatment of breast cancer underwent extensive progress in recent years with molecularly targeted therapies. However, non-specific pharmaceutical approaches (chemotherapy) persist, inducing severe side-effects. Phytochemicals provide a promising alternative for breast cancer prevention and treatment. Specifically, resveratrol (res) is a plant-derived polyphenolic phytoalexin with potent biological activity but displays poor water solubility, limiting its clinical use. Here we have developed a strategy for delivering res using a newly synthesized nano-carrier with the potential for both diagnosis and treatment.

Methods: Res-loaded nanoparticles were synthesized by the emulsion method using Pluronic F127 block copolymer and Vitamin E-TPGS. Nanoparticle characterization was performed by SEM and tunable resistive pulse sensing. Encapsulation Efficiency (EE%) and Drug Loading (DL%) content were determined by analysis of the supernatant during synthesis. Nanoparticle uptake kinetics in breast cancer cell lines MCF-7 and MDA-MB-231 as well as in MCF-10A breast epithelial cells were evaluated by flow cytometry and the effects of res on cell viability via MTT assay.

Results: Res-loaded nanoparticles with spherical shape and a dominant size of 179±22 nm were produced. Res was loaded with high EE of 73±0.9% and DL content of 6.2±0.1%. Flow cytometry revealed higher uptake efficiency in breast cancer cells compared to the control. An MTT assay showed that res-loaded nanoparticles reduced the viability of breast cancer cells with no effect on the control cells.

Conclusions: These results demonstrate that the newly synthesized nanoparticle is a good model for the encapsulation of hydrophobic drugs. Additionally, the nanoparticle delivers a natural compound and is highly effective and selective against breast cancer cells rendering this type of nanoparticle an excellent candidate for diagnosis and therapy of difficult to treat mammary malignancies.

Rhus coriaria L. (Sumac) Demonstrates Oncostatic Activity in the Therapeutic and Preventive Model of Breast Carcinoma

Comprehensive scientific data provide evidence that isolated phytochemicals or whole plant foods may beneficially modify carcinogenesis. The aim of this study was to evaluate the oncostatic activities of Rhus coriaria L. (sumac) using animal models (rat and mouse), and cell lines of breast carcinoma. R. coriaria (as a powder) was administered through the diet at two concentrations (low dose: 0.1% (w/w) and high dose: 1 % (w/w)) for the duration of the experiment in a syngeneic 4T1 mouse and chemically-induced rat mammary carcinoma models. After autopsy, histopathological and molecular analyses of tumor samples in rodents were performed. Moreover, in vitro analyses using MCF-7 and MDA-MB-231 cells were conducted. The dominant metabolites present in tested R. coriaria methanolic extract were glycosides of gallic acid (possible gallotannins). In the mouse model, R. coriaria at a higher dose (1%) significantly decreased tumor volume by 27% when compared to controls. In addition, treated tumors showed significant dose-dependent decrease in mitotic activity index by 36.5% and 51% in comparison with the control group. In the chemoprevention study using rats, R. coriaria at a higher dose significantly reduced the tumor incidence by 20% and in lower dose non-significantly reduced tumor frequency by 29% when compared to controls. Evaluations of the mechanism of oncostatic action using valid clinical markers demonstrated several positive alterations in rat tumor cells after the treatment with R. coriaria. In this regard, histopathological analysis of treated tumor specimens showed robust dose-dependent decrease in the ratio of high-/low-grade carcinomas by 66% and 73% compared to controls. In treated rat carcinomas, we found significant caspase-3, Bax, and Bax/Bcl-2 expression increases; on the other side, a significant down-regulation of Bcl-2, Ki67, CD24, ALDH1, and EpCam expressions and MDA levels. When compared to control specimens, evaluation of epigenetic alterations in rat tumor cells in vivo showed significant dose-dependent decrease in lysine methylation status of H3K4m3 and H3K9m3 and dose-dependent increase in lysine acetylation in H4K16ac levels (H4K20m3 was not changed) in treated groups. However, only in lower dose of sumac were significant decreases in the expression of oncogenic miR210 and increase of tumor-suppressive miR145 (miR21, miR22, and miR155 were not changed) observed. Finally, only in lower sumac dose, significant decreases in methylation status of three out of five gene promoters-ATM, PTEN, and TIMP3 (PITX2 and RASSF1 promoters were not changed). In vitro evaluations using methanolic extract of R. coriaria showed significant anticancer efficacy in MCF-7 and MDA-MB-231 cells (using Resazurin, cell cycle, annexin V/PI, caspase-3/7, Bcl-2, PARP, and mitochondrial membrane potential analyses). In conclusion, sumac demonstrated significant oncostatic activities in rodent models of breast carcinoma that were validated by mechanistic studies in vivo and in vitro.

Mechanisms of Taxane Resistance

The taxane family of chemotherapy drugs has been used to treat a variety of mostly epithelial-derived tumors and remain the first-line treatment for some cancers. Despite the improved survival time and reduction of tumor size observed in some patients, many have no response to the drugs or develop resistance over time. Taxane resistance is multi-faceted and involves multiple pathways in proliferation, apoptosis, metabolism, and the transport of foreign substances. In this review, we dive deeper into hypothesized resistance mechanisms from research during the last decade, with a focus on the cancer types that use taxanes as first-line treatment but frequently develop resistance to them. Furthermore, we will discuss current clinical inhibitors and those yet to be approved that target key pathways or proteins and aim to reverse resistance in combination with taxanes or individually. Lastly, we will highlight taxane response biomarkers, specific genes with monitored expression and correlated with response to taxanes, mentioning those currently being used and those that should be adopted. The future directions of taxanes involve more personalized approaches to treatment by tailoring drug-inhibitor combinations or alternatives depending on levels of resistance biomarkers. We hope that this review will identify gaps in knowledge surrounding taxane resistance that future research or clinical trials can overcome.

Maltotriose Conjugated Metal-Organic Frameworks for Selective Targeting and Photodynamic Therapy of Triple Negative Breast Cancer Cells and Tumor Associated Macrophages

Herein, we report a nano-MOF conjugated to maltotriose as a new DDS. MA-PCN-224-0.1Mn/0.9Zn showed its ability to target cancer and TAM. This novel MOF is an effective PDT agent and shows little dark toxicity, MA-PCN-224-0.1Mn/0.9Zn uptakes selectively into cancer cells. A well-suited size control methodology was used so that the nano-scaled MOFs may take advantage of the EPR effect. This development of a nano-scale MOF for PDT that is conjugated to a cancer targeting ligand represents a meaningful development for the use of MOFs as drug delivery systems.

Calcium Homeostasis: A Potential Vicious Cycle of Bone Metastasis in Breast Cancers

Cancers have been considered as one of the most severe health problems in the world. Efforts to elucidate the cancer progression reveal the importance of bone metastasis for tumor malignancy, one of the leading causes for high mortality rate. Multiple cancers develop bone metastasis, from which breast cancers exhibit the highest rate and have been well-recognized. Numerous cells and environmental factors have been believed to synergistically facilitate bone metastasis in breast cancers, from which breast cancer cells, osteoclasts, osteoblasts, and their produced cytokines have been well-recognized to form a vicious cycle that aggravates tumor malignancy. Except the cytokines or chemokines, calcium ions are another element largely released from bones during bone metastasis that leads to hypercalcemia, however, have not been well-characterized yet in modulation of bone metastasis. Calcium ions act as a type of unique second messenger that exhibits omnipotent functions in numerous cells, including tumor cells, osteoclasts, and osteoblasts. Calcium ions cannot be produced in the cells and are dynamically fluxed among extracellular calcium pools, intracellular calcium storages and cytosolic calcium signals, namely calcium homeostasis, raising a possibility that calcium ions released from bone during bone metastasis would further enhance bone metastasis and aggravate tumor progression via the vicious cycle due to abnormal calcium homeostasis in breast cancer cells, osteoclasts and osteoblasts. TRPs, VGCCs, SOCE, and P2Xs are four major calcium channels/routes mediating extracellular calcium entry and affect calcium homeostasis. Here we will summarize the overall functions of these four calcium channels in breast cancer cells, osteoclasts and osteoblasts, providing evidence of calcium homeostasis as a vicious cycle in modulation of bone metastasis in breast cancers.

Anti-Migratory and Pro-Apoptotic Properties of Parvifloron D on Triple-Negative Breast Cancer Cells

Medicinal plants are important sources of new bioactive compounds with potential anticancer activity. Parvifloron D (ParvD) is an abietane diterpenoid, isolated in high amounts from Plectranthus ecklonii Benth. Previous reports have suggested potential therapeutic properties for ParvD. ParvD has shown pro-apoptotic and cytotoxic effects in leukemia and melanoma cell lines. However, to the best of our knowledge, there are no studies in triple-negative breast cancer (TNBC) models. TNBC is a breast cancer subtype characterized by an aggressive behavior with poor clinical outcomes and weak overall therapeutic responses to the current treatment options. This work aimed at evaluating the anticancer effect of ParvD in MDA-MB-231 cells, a model of human TNBC. To obtain sufficient amounts of purified ParvD the efficiency of several extraction methods was compared. ParvD (0.1–10 µM) decreased cell viability in a concentration-dependent manner. Treatment with ParvD (5 µM) significantly increased the percentage of apoptotic nuclei and exposure to 3 µM ParvD increased the sub-G1 population. Since altered cell adherence, migration, and invasion are determinant processes for the formation of metastases, the effect of ParvD on these cellular processes was tested. Although treatment with ParvD (1 µM) had no effect on cell-substrate attachment, ParvD (1 µM) significantly reduced cell chemotaxis and invasion. This is the first report describing the proapoptotic effect of ParvD in TNBC cells. Moreover, for the first time we have shown that ParvD reduces cell motility, unraveling potential anti-metastatic properties.

Increase in fatty acids and flotillins upon resveratrol treatment of human breast cancer cells

Flotillin-1 and flotillin-2 are highly conserved proteins that localize into cholesterol-rich microdomains in cellular membranes. Flotillins are closely related to the occurrence and development of various types of human cancers. Flotillin-1 is highly expressed in breast cancer, and the high expression level of flotillin-1 is significantly correlated with poorer patient survival. Here we studied the relationship between the formation of lipid rafts and the expression of flotillins and lipids in human breast cancer cells. We used the polyphenol compound resveratrol to alter the structure and function of the plasma membrane. Our data revealed an increase in fatty acids in MCF-7 and MDA-MB-231 cells upon resveratrol treatment. Interestingly, we also found an increase in the expression of both flotillin-1 and flotillin-2 in breast tumor cells after treatment. Resveratrol also induced changes in the pattern of flotillin distribution among detergent-resistant lipid rafts fractions in both cell lines and induced the nuclear translocation of flotillin-2. Since resveratrol has been pointed out as a putative cancer therapy agent, our results could have an impact on the understanding of the effects of resveratrol in tumor cells.

Quantitative proteomic analysis of enhanced cellular effects of electrochemotherapy with Cisplatin in triple-negative breast cancer cells

Due to the lack of the three main receptors, triple negative breast cancer (TNBC) is refractive to standard chemotherapy. Hence, alternate therapies are needed. TNBCs utilize glycolysis, which heightens their growth, proliferation, invasiveness, chemotherapeutic resistance and poor therapeutic response. This calls for novel therapeutic strategies to target these metabolic vulnerabilities present in TNBC. Electroporation-mediated chemotherapy, known as electrochemotherapy (ECT) is gaining momentum as an attractive alternative. However, its molecular mechanisms need better understanding. Towards this, label-free quantitative proteomics is utilized to gain insight into the anticancer mechanisms of ECT using electrical pulses (EP) and Cisplatin (CsP) on MDA-MB-231, human TNBC cells. The results indicate that EP + CsP significantly downregulated 14 key glycolysis proteins (including ENO1, LDHA, LDHB, ACSS2, ALDOA, and PGK1), compared to CsP alone. EP + CsP caused a switch in the metabolism with upregulation of 34 oxidative phosphorylation pathway proteins and 18 tricarboxylic acid (TCA) cycle proteins compared to CsP alone, accompanied by the upregulation of proteins linked to several metabolic reactions, which produce TCA cycle intermediates. Moreover, EP + CsP promoted multiple pathways to cause 1.3-fold increase in the reactive oxygen species concentration and induced apoptosis. The proteomics results correlate well with cell viability, western blot, and qPCR data. While some effects were similar for EP, more comprehensive and long-lasting effects were observed for EP + CsP, which demonstrate the potential of EP + CsP against TNBC cells.

A Unique Morphological Phenotype in Chemoresistant Triple-Negative Breast Cancer Reveals Metabolic Reprogramming and PLIN4 Expression as a Molecular Vulnerability

The major obstacle in successfully treating triple-negative breast cancer (TNBC) is resistance to cytotoxic chemotherapy, the mainstay of treatment in this disease. Previous preclinical models of chemoresistance in TNBC have suffered from a lack of clinical relevance. Using a single high dose chemotherapy treatment, we developed a novel MDA-MB-436 cell-based model of chemoresistance characterized by a unique and complex morphologic phenotype, which consists of polyploid giant cancer cells giving rise to neuron-like mononuclear daughter cells filled with smaller but functional mitochondria and numerous lipid droplets. This resistant phenotype is associated with metabolic reprogramming with a shift to a greater dependence on fatty acids and oxidative phosphorylation. We validated both the molecular and histologic features of this model in a clinical cohort of primary chemoresistant TNBCs and identified several metabolic vulnerabilities including a dependence on PLIN4, a perilipin coating the observed lipid droplets, expressed both in the TNBC-resistant cells and clinical chemoresistant tumors treated with neoadjuvant doxorubicin-based chemotherapy. These findings thus reveal a novel mechanism of chemotherapy resistance that has therapeutic implications in the treatment of drug-resistant cancer. IMPLICATIONS: These findings underlie the importance of a novel morphologic-metabolic phenotype associated with chemotherapy resistance in TNBC, and bring to light novel therapeutic targets resulting from vulnerabilities in this phenotype, including the expression of PLIN4 essential for stabilizing lipid droplets in resistant cells.

Polymer design and component selection contribute to uptake, distribution & trafficking behaviours of polyethylene glycol hyperbranched polymers in live MDA-MB-468 breast cancer cells

As polymeric nanomedicines grow increasingly complex in design, an effective therapeutic release is often inherently tied to localisation to specific intracellular compartments or microenvironments. The inclusion of environmentally-sensitive moieties links the functionality of such materials to the trafficking behaviours exhibited once materials have obtained access to the cellular milieu. In order to perform their designed function, such materials often need to encounter specific biological cues or stimuli. As such, there is an increased need to improve our understanding of how the physicochemical properties of nanomaterials influence post-internalisation behaviours. Amongst the unknown factors that may contribute to the trafficking behaviours and distribution of polymers within the cellular environment, is the influence of the components selected in the development of such materials. To examine whether composition and arrangement of components within small polymeric nanomaterials contribute to their ability to navigate the intracellular space, here we utilise fluorophores to model component selection, varying the fluorescent handle selected and its method of incorporation. We explore the intracellular behaviours of well-characterised hyperbranched polymers in live MDA-MB-468 breast cancer cells in vitro. Changes in distribution as a function of both fluorophore selection and placement are reported, and our data suggest that the individual components used to produce potential nanomedicines are critical to their overall functioning and efficacy. Further to this, through the use of a novel non-conjugated targeting ligand, we demonstrate that there is inherent competition between component-directing factors and cellular influences on the ultimate fate of the polymers. The behaviours reported here suggest that not only does component selection contribute to intracellular processing, but these factors could potentially be harnessed when designing polymers to ensure improved functionality of future materials for therapeutic delivery.

LIFR-AS1 modulates Sufu to inhibit cell proliferation and migration by miR-197-3p in breast cancer

Numerous evidence has recently demonstrated that long non-coding RNAs (lncRNAs) play vital roles in the oncogenesis and development of a wide range of human neoplasms. Leukemia inhibitory factor receptor antisense RNA 1 (LIFR-AS1), a novel cancer-related lncRNA, has been reported to be under-expressed in breast cancer and associated with poor prognosis. However, the exact role of LIFR-AS1 in breast cancer remains largely unclear. The present study aimed to investigate the biological role of LIFR-AS1 in breast cancer and clarify the potential molecular mechanisms. In the present study, we found that LIFR-AS1 was significantly down-regulated in both tissues and cell lines. Furthermore, over-expression of LIFR-AS1 inhibited breast cancer cell proliferation, colony formation, migration and invasion, whereas knockdown of LIFR-AS1 promoted breast cancer cell proliferation, colony formation, migration and invasion. Moreover, LIFR-AS1 was observed to up-regulate suppressor of fused gene (Sufu) expression by competitively binding to miR-197-3p in breast cancer cells. Notably, miR-197-3p inhibitor reversed the promoting effects of LIFR-AS1 knockdown on breast cancer cell proliferation, colony formation, migration and invasion. Additionally, LIFR-AS1 knockdown promoted tumor growth in vivo To sum up, our results imply the tumor-suppressing role of LIFR-AS1 in breast cancer.

Diplatinum(II) Catecholate of Photoactive Boron-Dipyrromethene for Lysosome-Targeted Photodynamic Therapy in Red Light

The binuclear platinum(II) boron-dipyrromethene (BODIPY) complex [{Pt(dach)}₂(μ-Dcrb)] (DP), where dach is 1,2-diaminocyclohexane and H₄Dcrb is a morpholine-conjugated BODIPY-linked dicatechol bridging ligand, was prepared for lysosome organelle targeting and near-IR (NIR) light (600-720 nm) induced photocytotoxic activity. The platinum complex [Pt(dach)(cat)] (CP), where H₂cat is catechol, was synthesized and used as a control complex without bearing the BODIPY unit. The complex DP displayed a band at 660 nm (ε = 2.1 × 10⁴ M^-1 cm^-1) in the red region of the UV-visible spectrum recorded in 10% dimethyl sulfoxide/Dulbecco's Modified Eagle's Medium (DMSO/DMEM, pH 7.2). The complex DP and the BODIPY ligand displayed emission in 10% DMSO-DMEM (pH 7.2) giving an λ_em value of 668 nm (λ_ex = 650 nm) with a Φ_F value of 0.02 for DP and 0.16 for H₄Dcrb (Φ_F, fluorescence quantum yield). Titration experiments using 1,3-diphenylisobenzofuran (DPBF) indicated that the complex DP and H₄Dcrb on irradiation with near-IR light of 600-720 nm generated singlet oxygen (¹O₂) as the ROS (reactive oxygen species). The complex DP showed significant lysosomal localization and remarkable apoptotic photodynamic therapy (PDT) effects, giving half-maximal inhibitory concentration values (IC₅₀) within 0.6-3.4 μM in HeLa cervical cancer, A549 lung cancer, and MDA-MB231 multidrug resistant cancer cells, while being essentially nontoxic in the dark and in the HPL1D immortalized lung epithelial normal cells. The acridine orange assay using A549 cells showed lysosomal membrane permeabilization by the complex DP under near-IR light (600-720 nm). This complex on near-IR light (600-720 nm) activation in A549 cells induced apoptotic cell death, as observed from an Annexin-V FITC assay.

Knockdown of TM9SF4 boosts ER stress to trigger cell death of chemoresistant breast cancer cells

Drug resistance is one of the major obstacles to breast cancer therapy. However, the mechanisms of how cancer cells develop chemoresistance are still not fully understood. In the present study, we found that expression of TM9SF4 proteins was much higher in adriamycin (ADM)-resistant breast cancer cells MCF-7/ADM than in its parental line wild-type breast cancer cells MCF-7/WT. shRNA-mediated knockdown of TM9SF4 preferentially reduced cell growth and triggered cell death in chemoresistant MCF-7/ADM cells compared with MCF-7/WT cells. Knockdown of TM9SF4 also reduced cell growth and triggered cell death in chemoresistant MDA-MB-231/GEM cells. Mechanistic studies showed that TM9SF4 knockdown increased protein misfolding and elevated endoplasmic reticulum (ER) stress level in MCF-7/ADM cells, as indicated by aggresome formation and upregulated expression of ER stress markers, the effect of which was reversed by a small molecule chaperone 4-phenybutyric acid. In an athymic nude mouse model of ADM-resistant human breast xenograft tumor, knockdown of TM9SF4 decreased the growth of tumor xenografts. In chemoresistant breast cancer patients, chemotherapy increased the expression of TM9SF4 proteins in breast tumor samples. Taken together, these results uncovered a novel role of TM9SF4 proteins in alleviating ER stress and protecting chemoresistant breast cancer cells from apoptotic/necrotic cell death. These results highlight a possible strategy of targeting TM9SF4 to overcome breast cancer chemoresistance.

Simultaneous defeat of MCF7 and MDA-MB-231 resistances by a hypericin PDT-tamoxifen hybrid therapy

Currently the greatest challenge in oncology is the lack of homogeneity of the lesions where different cell components respond differently to treatment. There is growing consensus that monotherapies are insufficient to eradicate the disease and there is an unmet need for more potent combinatorial treatments. We have previously shown that hypericin photodynamic therapy (HYP-PDT) triggers electron transport chain (ETC) inhibition in cell mitochondria. We have also shown that tamoxifen (TAM) enhances cytotoxicity in cells with high respiration, when combined with ETC inhibitors. Herein we introduce a synergistic treatment based on TAM chemotherapy and HYP-PDT. We tested this novel combinatorial treatment (HYPERTAM) in two metabolically different breast cancer cell lines, the triple-negative MDA-MB-231 and the estrogen-receptor-positive MCF7, the former being quite sensitive to HYP-PDT while the latter very responsive to TAM treatment. In addition, we investigated the mode of death, effect of lipid peroxidation, and the effect on cell metabolism. The results were quite astounding. HYPERTAM exhibited over 90% cytotoxicity in both cell lines. This cytotoxicity was in the form of both necrosis and autophagy, while high levels of lipid peroxidation were observed in both cell lines. We, consequently, translated our research to an in vivo pilot study encompassing the MDA-MB-231 and MCF7 tumor models in NOD SCID-γ immunocompromised mice. Both treatment cohorts responded very positively to HYPERTRAM, which significantly prolonged mice survival. HYPERTAM is a potent, synergistic modality, which may lay the foundations for a novel, composite anticancer treatment, effective in diverse tumor types.

Synthesis and evolution of S-Porphin sodium as a potential antitumor agent for photodynamic therapy against breast cancer

The novel sensitizer S-Porphin sodium can generate ROS by radiation with a long wavelength to cause tumor cell death.

Choline-Amino Acid Ionic Liquids as Green Functional Excipients to Enhance Drug Solubility

The development of effective forms to incorporate poorly soluble drugs into delivery systems remains a problem. Thus, it is important to find alternatives such as finding excipients that increase drug solubility. Ionic liquids (ILs), particularly choline-based ILs, have been studied as solubility enhancers in drug delivery systems. Nonetheless, to acknowledge this property as a functionality, it needs to be proven at non-toxic concentrations. Hence, herein two choline-amino acid ILs were studied as functional excipients by evaluating their influence on the solubility of the poorly water-soluble ferulic acid and rutin, while considering their safety. The solubility of the drugs was always higher in the presence of the ILs than in water. Ionic liquids did not affect the radical scavenging activity of the drugs or the cell viability. Moreover, stable oil-in-water (O/W) emulsions were prepared containing each drug and the ILs, allowing a significantly higher drug loading. Globally, our results suggest that choline-based ILs may act as green functional excipients, since at non-toxic concentrations they considerably improve drug solubility/loading, without influencing the antioxidant activity of the drugs, the cell viability, or the stability of the formulations.

Antitumor activity of cell-penetrant kinin B1 receptor antagonists in human triple-negative breast cancer cells

High nuclear expression of G protein-coupled receptors, including kinin B1 receptors (B1R), has been observed in several human cancers, but the clinical significance of this is unknown. We put forward the hypothesis that these "nuclearized" kinin B1R contribute to tumorigenicity and can be a new target in anticancer strategies. Our initial immunostaining and ultrastructural electron microscopy analyses demonstrated high B1R expression predominantly located at internal/nuclear compartments in the MDA-MB-231 triple-negative breast cancer (TNBC) cell line as well as in clinical samples of patients with TNBC. On the basis of these findings, in the present study, we evaluated the anticancer therapeutic potential of newly identified, cell-permeable B1R antagonists in MDA-MB-231 cells (ligand-receptor binding/activity assays and LC-MS/MS analyses). We found that these compounds (SSR240612, NG67, and N2000) were more toxic to MDA-MB-231 cells in comparison with low- or non-B1R expressing MCF-10A normal human mammary epithelial cells and COS-1 cells, respectively (clonogenic, MTT proliferative/cytocidal assays, and fluorescence-activated cell-sorting (FACS)-based apoptosis analyses). By comparison, the peptide B1R antagonist R954 unable to cross cell membrane failed to produce anticancer effects. Furthermore, the putative mechanisms underlying the anticancer activities of cell-penetrant B1R antagonists were assessed by analyzing cell cycle regulation and signaling molecules related to cell survival and apoptosis (FACS and western blot). Finally, drug combination experiments showed that cell-penetrant B1R antagonists can cooperate with suboptimal doses of chemotherapeutic agents (doxorubicin and paclitaxel) to promote TNBC death. This study provides evidence on the potential value of internally acting kinin B1R antagonists in averting growth of breast cancer.

N-desmethyl tamoxifen and quercetin-loaded multiwalled CNTs: A synergistic approach to overcome MDR in cancer cells

Our aim was to develop multiwalled carbon nanotubes (MWCNTs)-based nanoconstructs for the codelivery of N-desmethyl tamoxifen (N-TAM) and a mild P-gp efflux inhibitor, i.e., quercetin (QT) to treat multiple drug resistant (MDR) cancer cells. The hypothesis banks on three-tier attack on the MDR mechanisms viz. drug derivatization, MWCNT permeation and P-gp inhibition. Tamoxifen was converted to N-TAM and was conjugated to carboxylated MWCNTs mediated by a biodegradable linker, i.e., tetraethylene glycol (TEG). QT was adsorbed on the conjugate to fetch the final product, i.e., N-TAM-TEG-MWCNT-QT. Spectroscopic analysis confirmed successful conjugation of N-TAM and physical adsorption of QT. The in-vitro release of N-TAM from the N-TAM-TEG-MWCNT conjugate was minimal to that of pure drug under physiological conditions, but markedly enhanced under the acidic pH of cancer cells. The developed nanometeric formulation was found to be haemo-compatible. Reduced IC₅₀values and better cellular uptake in drug resistant MDA-MB-231 cells were observed, followed by enhanced drug availability in the systemic circulation of rodents vis-à-vis naïve drug. The smart nanosystem conferred the desired temporal drug delivery, enhanced drug efficacy, biocompatibility and conducive pharmacokinetics, which are the crucial desired attributes to tackle the increasing concern of MDR in cancer chemotherapy.

Remotely Phototriggered, Transferrin-Targeted Polymeric Nanoparticles for the Treatment of Breast Cancer

Triple-negative breast cancer (TNBC) has the worst prognosis among all subtypes of breast cancer. Currently, no targeted treatment has been approved for TNBC. The goal of this study was to design a remotely triggered, targeted therapy for TNBC using polymeric nanoparticles and light. Active targeting of TNBC was achieved by conjugating the nanoparticles to a peptide (hTf) that binds to the transferrin receptor, which is overexpressed in TNBC. Photodynamic therapy (PDT) was explored for TNBC treatment by remotely triggering benzoporphyrin derivative monoacid (BPD), a photosensitizer, using near-infrared light. In this study, we investigated the use of actively targeting polymeric nanoparticles for PDT against TNBC using in vitro imaging and cytotoxicity studies. Fluorescence imaging confirmed that the BPD-loaded nanoparticles showed greater fluorescence in TNBC cells compared to free BPD, but more importantly, actively targeted nanoparticles displayed stronger fluorescence compared to passively targeted nanoparticles. Moreover, fluorescence imaging following competition with empty targeted nanoparticles validated the specificity of the targeted nanoparticles for TNBC cells. The PDT killing results were in line with the fluorescence imaging results, where actively targeting nanoparticles exhibited the highest phototriggered cytotoxicity in TNBC cells, making them an attractive nanoplatform for TNBC treatment.

The effect of chemotherapy on programmed cell death 1/programmed cell death 1 ligand axis: some chemotherapeutical drugs may finally work through immune response

Most tumors are immunogenic which would trigger some immune response. Chemotherapy also has immune potentiating mechanisms of action. But it is unknown whether the immune response is associated with the efficacy of chemotherapy and the development of chemoresistance. Recently, there is a growing interest in immunotherapy, among which the co-inhibitory molecules, programmed cell death 1/programmed cell death 1 ligand (PD-1/PD-L1) leads to immune evasion. Since some reports showed that conventional chemotherapeutics can induce the expression of PD-L1, we try to summarize the effect of chemotherapy on PD-1/PD-L1 axis and some potential molecules relevant to PD-1/PD-L1 in chemoresistance in this review.

Targeting intracellular B2 receptors using novel cell-penetrating antagonists to arrest growth and induce apoptosis in human triple-negative breast cancer

G protein-coupled receptors (GPCRs) are integral cell-surface proteins having a central role in tumor growth and metastasis. However, several GPCRs retain an atypical intracellular/nuclear location in various types of cancer. The pathological significance of this is currently unknown. Here we extend this observation by showing that the bradykinin B2R (BK-B2R) is nuclearly expressed in the human triple-negative breast cancer (TNBC) cell line MDA-MB-231 and in human clinical specimens of TNBC. We posited that these “nuclearized” receptors could be involved in oncogenic signaling linked to aberrant growth and survival maintenance of TNBC. We used cell-penetrating BK-B2R antagonists, including FR173657 and novel transducible, cell-permeable forms of the peptide B2R antagonist HOE 140 (NG68, NG134) to demonstrate their superior efficacy over impermeable ones (HOE 140), in blocking proliferation and promoting apoptosis of MDA-MB-231 cells. Some showed an even greater antineoplastic activity over conventional chemotherapeutic drugs in vitro. The cell-permeable B2R antagonists had less to no anticancer effects on B2R shRNA-knockdown or non-B2R expressing (COS-1) cells, indicating specificity in their action. Possible mechanisms of their anticancer effects may involve activation of p38kinase/p27^Kip1 pathways. Together, our data support the existence of a possible intracrine signaling pathway via internal/nuclear B2R, critical for the growth of TNBC cells, and identify new chemical entities that enable to target the corresponding intracellular GPCRs.