EGFR Transgene Stimulates Spontaneous Formation of MCF7 Breast Cancer Cells Spheroids with Partly Loss of HER3 Receptor

Multicellular spheroids with 3D cell–cell interactions are a useful model to simulate the growth conditions of cancer. There is evidence that in tumor spheroids, the expression of various essential molecules is changed compared to the adherent form of cell cultures. These changes include growth factor receptors and ABC transporters and result in the enhanced invasiveness of the cells and drug resistance. It is known that breast adenocarcinoma MCF7 cells can spontaneously form 3D spheroids and such spheroids are characterized by high expression of EGFR/HER2, while the natural phenotype of MCF7 cells is EGFR^low/HER2^low. Therefore, it was interesting to reveal if high epidermal growth factor receptor (EGFR) expression is sufficient for the conversion of adherent MCF7 to spheroids. In this study, an MCF7 cell line with high expression of EGFR was engineered using the retroviral transduction method. These MCF7-EGFR cells assembled in spheroids very quickly and grew predominantly as a 3D suspension culture with no special plates, scaffolds, growth supplements, or exogenous matrixes. These spheroids were characterized by a rounded shape with a well-defined external border and 100 µM median diameter. The sphere-forming ability of MCF7-EGFR cells was up to 5 times stronger than in MCF7^wt cells. Thus, high EGFR expression was the initiation factor of conversion of adherent MCF7^wt cells to spheroids. MCF7-EGFR spheroids were enriched by the cells with a cancer stem cell (CSC) phenotype CD24^−/low/CD44⁻ in comparison with parental MCF7^wt cells and MCF7-EGFR adhesive cells. We suppose that these properties of MCF7-EGFR spheroids originate from the typical features of parental MCF7 cells. We showed the decreasing of HER3 receptors in MCF7-EGFR spheroids compared to that in MCF^wt and in adherent MCF7-EGFR cells, and the same decrease was observed in the MCF7^wt spheroids growing under the growth factors stimulation. To summarize, the expression of EGFR transgene in MCF7 cells stimulates rapid spheroids formation; these spheroids are enriched by CSC-like CD24⁻/CD44⁻ cells, they partly lose HER3 receptors, and are characterized by a lower potency in drug resistance pomp activation compared to MCF7^wt. These MCF7-EGFR spheroids are a useful cancer model for the development of anticancer drugs, including EGFR-targeted therapeutics.     

Preclinical Evaluation of 99mTc-ZHER2:41071, a Second-Generation Affibody-Based HER2-Visualizing Imaging Probe with a Low Renal Uptake

Radionuclide imaging of HER2 expression in tumours may enable stratification of patients with breast, ovarian, and gastroesophageal cancers for HER2-targeting therapies. A first-generation HER2-binding affibody molecule [^99mTc]Tc-ZHER2:V2 demonstrated favorable imaging properties in preclinical studies. Thereafter, the affibody scaffold has been extensively modified, which increased its melting point, improved storage stability, and increased hydrophilicity of the surface. In this study, a second-generation affibody molecule (designated ZHER2:41071) with a new improved scaffold has been prepared and characterized. HER2-binding, biodistribution, and tumour-targeting properties of [^99mTc]Tc-labelled ZHER2:41071 were investigated. These properties were compared with properties of the first-generation affibody molecules, [^99mTc]Tc-ZHER2:V2 and [^99mTc]Tc-ZHER2:2395. [^99mTc]Tc-ZHER2:41071 bound specifically to HER2 expressing cells with an affinity of 58 ± 2 pM. The renal uptake for [^99mTc]Tc-ZHER2:41071 and [^99mTc]Tc-ZHER2:V2 was 25–30 fold lower when compared with [^99mTc]Tc-ZHER2:2395. The uptake in tumour and kidney for [^99mTc]Tc-ZHER2:41071 and [^99mTc]Tc-ZHER2:V2 in SKOV-3 xenografts was similar. In conclusion, an extensive re-engineering of the scaffold did not compromise imaging properties of the affibody molecule labelled with ^99mTc using a GGGC chelator. The new probe, [^99mTc]Tc-ZHER2:41071 provided the best tumour-to-blood ratio compared to HER2-imaging probes for single photon emission computed tomography (SPECT) described in the literature so far. [^99mTc]Tc-ZHER2:41071 is a promising candidate for further clinical translation studies.     

Soluble Cytoplasmic Expression and Purification of Immunotoxin HER2(scFv)-PE24B as a Maltose Binding Protein Fusion

Human epidermal growth factor receptor 2 (HER-2) is overexpressed in many malignant tumors. The anti-HER2 antibody trastuzumab has been approved for treating HER2-positive early and metastatic breast cancers. Pseudomonas exotoxin A (PE), a bacterial toxin of Pseudomonas aeruginosa, consists of an A-domain with enzymatic activity and a B-domain with cell binding activity. Recombinant immunotoxins comprising the HER2(scFv) single-chain Fv from trastuzumab and the PE24B catalytic fragment of PE display promising cytotoxic effects, but immunotoxins are typically insoluble when expressed in the cytoplasm of Escherichia coli, and thus they require solubilization and refolding. Herein, a recombinant immunotoxin gene was fused with maltose binding protein (MBP) and overexpressed in a soluble form in E. coli. Removal of the MBP yielded stable HER2(scFv)-PE24B at 91% purity; 0.25 mg of pure HER2(scFv)-PE24B was obtained from a 500 mL flask culture. Purified HER2(scFv)-PE24B was tested against four breast cancer cell lines differing in their surface HER2 level. The immunotoxin showed stronger cytotoxicity than HER2(scFv) or PE24B alone. The IC₅₀ values for HER2(scFv)-PE24B were 28.1 ± 2.5 pM (n = 9) and 19 ± 1.4 pM (n = 9) for high HER2-positive cell lines SKBR3 and BT-474, respectively, but its cytotoxicity was lower against MDA-MB-231 and MCF7. Thus, fusion with MBP can facilitate the soluble expression and purification of scFv immunotoxins.     

Erythrocyte Membrane Nanomechanical Rigidity Is Decreased in Obese Patients

This work intends to describe the physical properties of red blood cell (RBC) membranes in obese adults. The hypothesis driving this research is that obesity, in addition to increasing the amount of body fat, will also modify the lipid composition of membranes in cells other than adipocytes. Forty-nine control volunteers (16 male, 33 female, BMI 21.8 ± 5.6 and 21.5 ± 4.2 kg/m², respectively) and 52 obese subjects (16 male and 36 female, BMI 38.2± 11.0 and 40.7 ± 8.7 kg/m², respectively) were examined. The two physical techniques applied were atomic force microscopy (AFM) in the force spectroscopy mode, which allows the micromechanical measurement of penetration forces, and fluorescence anisotropy of trimethylammonium diphenylhexatriene (TMA-DPH), which provides information on lipid order at the membrane polar–nonpolar interface. These techniques, in combination with lipidomic studies, revealed a decreased rigidity in the interfacial region of the RBC membranes of obese as compared to control patients, related to parallel changes in lipid composition. Lipidomic data show an increase in the cholesterol/phospholipid mole ratio and a decrease in sphingomyelin contents in obese membranes. ω-3 fatty acids (e.g., docosahexaenoic acid) appear to be less prevalent in obese patient RBCs, and this is the case for both the global fatty acid distribution and for the individual major lipids in the membrane phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidylserine (PS). Moreover, some ω-6 fatty acids (e.g., arachidonic acid) are increased in obese patient RBCs. The switch from ω-3 to ω-6 lipids in obese subjects could be a major factor explaining the higher interfacial fluidity in obese patient RBC membranes.     

Involvement of the ERK/HIF-1α/EMT Pathway in XCL1-Induced Migration of MDA-MB-231 and SK-BR-3 Breast Cancer Cells

Chemokine–receptor interactions play multiple roles in cancer progression. It was reported that the overexpression of X-C motif chemokine receptor 1 (XCR1), a specific receptor for chemokine X-C motif chemokine ligand 1 (XCL1), stimulates the migration of MDA-MB-231 triple-negative breast cancer cells. However, the exact mechanisms of this process remain to be elucidated. Our study found that XCL1 treatment markedly enhanced MDA-MB-231 cell migration. Additionally, XCL1 treatment enhanced epithelial–mesenchymal transition (EMT) of MDA-MB-231 cells via E-cadherin downregulation and upregulation of N-cadherin and vimentin as well as increases in β-catenin nucleus translocation. Furthermore, XCL1 enhanced the expression of hypoxia-inducible factor-1α (HIF-1α) and phosphorylation of extracellular signal-regulated kinase (ERK) 1/2. Notably, the effects of XCL1 on cell migration and intracellular signaling were negated by knockdown of XCR1 using siRNA, confirming XCR1-mediated actions. Treating MDA-MB-231 cells with U0126, a specific mitogen-activated protein kinase kinase (MEK) 1/2 inhibitor, blocked XCL1-induced HIF-1α accumulation and cell migration. The effect of XCL1 on cell migration was also evaluated in ER^-/HER2⁺ SK-BR-3 cells. XCL1 also promoted cell migration, EMT induction, HIF-1α accumulation, and ERK phosphorylation in SK-BR-3 cells. While XCL1 did not exhibit any significant impact on the matrix metalloproteinase (MMP)-2 and -9 expressions in MDA-MB-231 cells, it increased the expression of these enzymes in SK-BR-3 cells. Collectively, our results demonstrate that activation of the ERK/HIF-1α/EMT pathway is involved in the XCL1-induced migration of both MDA-MB-231 and SK-BR-3 breast cancer cells. Based on our findings, the XCL1–XCR1 interaction and its associated signaling molecules may serve as specific targets for the prevention of breast cancer cell migration and metastasis.     

Fabrication of low-density GaN/AlN quantum dots via GaN thermal decomposition in MOCVD

With an appropriate high anneal temperature under H₂ atmosphere, GaN quantum dots (QDs) have been fabricated via GaN thermal decomposition in metal organic chemical vapor deposition (MOCVD). Based on the characterization of atomic force microscopy (AFM), the obtained GaN QDs show good size distribution and have a low density of 2.4 × 10⁸ cm^-2. X-ray photoelectron spectroscopy (XPS) analysis demonstrates that the GaN QDs were formed without Ga droplets by thermal decomposition of GaN.     

Structure relaxation and crystallization of the CoW-CoNiW-NiW electrodeposited alloys

The structure of electrolytically deposited nanocrystalline alloys of the CoW-CoNiW-NiW systems under low-temperature heating was investigated by means of high-resolution transmission electron microscopy (HRTEM), high-angle annular dark-field scanning transmission electron microscopy (HAADF STEM), and analytical methods such as energy dispersive x-ray spectroscopy (EDS) and electron energy loss spectroscopy (EELS). Structural relaxation and crystallization were investigated at temperatures of 200°C to 300°C. The structural and compositional inhomogeneities were found in the CoW-CoNiW-NiW alloys, while the local changes in composition were found to reach 18 at.%. Nanocrystals in the alloys grew most intensely in the presence of a free surface, and we found their nuclei density to range from 2 × 10²³ /m³ to 3 × 10²³ /m³. It was determined that the local diffusion coefficient ranged from 0.9 to 1.7 10⁻¹⁸ m²/s, which could be explained by the prevalence of surface diffusion. The data gathered in these investigations can be used to predict the thermal stability of CoW-CoNiW-NiW alloys.     

Novel Nitrogen-Based Chalcone Analogs Provoke Substantial Apoptosis in HER2-Positive Human Breast Cancer Cells via JNK and ERK1/ERK2 Signaling Pathways

Natural chalcones possess antitumor properties and play a role as inducers of apoptosis, antioxidants and cytotoxic compounds. We recently reported that novel nitrogen chalcone-based compounds, which were generated in our lab, have specific effects on triple-negative breast cancer cells. However, the outcome of these two new compounds on human epidermal growth factor receptor 2 (HER2)-positive breast cancer remains nascent. Thus, we herein investigated the effects of these compounds (DK-13 and DK-14) on two HER2-positive breast cancer cell lines, SKBR3 and ZR75. Our data revealed that these compounds inhibit cell proliferation, deregulate cell-cycle progression and significantly induce cell apoptosis in both cell lines. Furthermore, the two chalcone compounds cause a significant reduction in the cell invasion ability of SKBR3 and ZR75 cancer cells. In parallel, we found that DK-13 and DK-14 inhibit colony formation of both cell lines in comparison to their matched controls. On the other hand, we noticed that these two compounds can inhibit angiogenesis in the chorioallantoic membrane model. The molecular pathway analysis of chalcone compounds exposed cells revealed that these compounds inhibit the expression of both JNK1/2/3 and ERK1/2, the major plausible molecular pathways behind these events. Our findings implicate that DK-13 and DK-14 possess effective chemotherapeutic outcomes against HER2-positive breast cancer via the ERK1/2 and JNK1/2/3 signaling pathways.     

Properties of Transport Mediated by the Human Organic Cation Transporter 2 Studied in a Polarized Three-Dimensional Epithelial Cell Culture Model

The renal secretory clearance for organic cations (neurotransmitters, metabolism products and drugs) is mediated by transporters specifically expressed in the basolateral and apical plasma membrane domains of proximal tubule cells. Here, human organic cation transporter 2 (hOCT2) is the main transporter for organic cations in the basolateral membrane domain. In this study, we stably expressed hOCT2 in Madin-Darby Canine Kidney (MDCK) cells and cultivated these cells in the presence of an extracellular matrix to obtain three-dimensional (3D) structures (cysts). The transport properties of hOCT2 expressed in MDCK cysts were compared with those measured using human embryonic kidney cells (HEK293) stably transfected with hOCT2 (hOCT2-HEK cells). In the MDCK cysts, hOCT2 was expressed in the basolateral membrane domain and showed a significant uptake of the fluorescent organic cation 4-(4-(dimethylamino)styryl)-N-methylpyridinium (ASP⁺) with an affinity (K_m) of 3.6 ± 1.2 µM, similar to what was measured in the hOCT2-HEK cells (K_m = 3.1 ± 0.2 µM). ASP⁺ uptake was inhibited by tetraethylammonium (TEA⁺), tetrapentylammonium (TPA⁺), metformin and baricitinib both in the hOCT2-HEK cells and the hOCT2- MDCK cysts, even though the apparent affinities of TEA⁺ and baricitinib were dependent on the expression system. Then, hOCT2 was subjected to the same rapid regulation by inhibition of p56^lck tyrosine kinase or calmodulin in the hOCT2-HEK cells and hOCT2- MDCK cysts. However, inhibition of casein kinase II regulated only activity of hOCT2 expressed in MDCK cysts and not in HEK cells. Taken together, these results suggest that the 3D cell culture model is a suitable tool for the functional analysis of hOCT2 transport properties, depending on cell polarization.     

Hybrid light-emitting diodes from anthracene-contained polymer and CdSe/ZnS core/shell quantum dots

In this paper, we added CdSe/ZnS core/shell quantum dots (QDs) into anthracene-contained polymer. The photoluminescent (PL) characteristic of polymer/QD composite film could identify the energy transitions of anthracene-contained polymer and QDs. Furthermore, the electroluminescent (EL) characteristic of hybrid LED also identifies emission peaks of blue polymer and QDs. The maximum luminescence of the device is 970 cd/m² with 9.1 wt.% QD hybrid emitter. The maximum luminous efficiency is 2.08 cd/A for the same device.     

HER2‐ and EGFR‐Specific Affiprobes: Novel Recombinant Optical Probes for Cell Imaging

The human epidermal growth factor receptors, EGFR and HER2, are members of the EGFR family of cell‐surface receptors/tyrosine kinases. EGFR‐ and HER2‐positive cancers represent a more aggressive disease with greater likelihood of recurrence, poorer prognosis, and decreased survival rate, compared to EGFR‐ or HER2‐negative cancers. The details of HER2 proto‐oncogenic functions are not deeply understood, partially because of a restricted availability of tools for EGFR and HER2 detection (A. Sorkin and L. K. Goh, Exp. Cell Res. 2009 , 315, 683–696). We have created photostable and relatively simple‐to‐produce imaging probes for in vitro staining of EGFR and HER2. These new reagents, called affiprobes, consist of a targeting moiety, a HER2‐ or EGFR‐specific Affibody® molecule, and a fluorescent moiety, mCherry (red) or EGFP (green). Our flow cytometry and confocal microscopy experiments demonstrated high specificity and signal/background ratio of affiprobes. Affiprobes are able to stain both live cells and frozen tumor xenograph sections. This type of optical probe can easily be extended for targeting other cell‐surface antigens/ receptors.     

Functional Transient Receptor Potential Ankyrin 1 and Vanilloid 1 Ion Channels Are Overexpressed in Human Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is a common cancer with poor prognosis. Transient Receptor Potential Ankyrin 1 (TRPA1) and Vanilloid 1 (TRPV1) receptors are non-selective cation channels expressed on primary sensory neurons and epithelial and immune cells. TRPV1 mRNA and immunopositivity, as well as TRPA1-like immunoreactivity upregulation, were demonstrated in OSCC, but selectivity problems with the antibodies still raise questions and their functional relevance is unclear. Therefore, here, we investigated TRPA1 and TRPV1 expressions in OSCC and analyzed their functions. TRPA1 and TRPV1 mRNA were determined by RNAscope in situ hybridization and qPCR. Radioactive ₄₅Ca²⁺ uptake and ATP-based luminescence indicating cell viability were measured in PE/CA-PJ41 cells in response to the TRPA1 agonist allyl-isothiocyanate (AITC) and TRPV1 agonist capsaicin to determine receptor function. Both TRPA1 and TRPV1 mRNA are expressed in the squamous epithelium of the human oral mucosa and in PE/CA-PJ41 cells, and their expressions are significantly upregulated in OSCC compared to healthy mucosa. TRPA1 and TRPV1 activation (100 µM AITC, 100 nM capsaicin) induced ₄₅Ca²⁺-influx into PE/CA-PJ41 cells. Both AITC (10 nM–5 µM) and capsaicin (100 nM–45 µM) reduced cell viability, reaching significant decrease at 100 nM AITC and 45 µM capsaicin. We provide the first evidence for the presence of non-neuronal TRPA1 receptor in the OSCC and confirm the expression of TRPV1 channel. These channels are functionally active and might regulate cancer cell viability.     

In Vitro Cytotoxicity of Trastuzumab (Tz) and Se-Trastuzumab (Se-Tz) against the Her/2 Breast Cancer Cell Lines JIMT-1 and BT-474

Her/2+ breast cancer accounts for ~25% mortality in women and overexpression of Her/2 leads to cell growth and tumor progression. Trastuzumab (Tz) with Taxane is the preferred treatment for Her/2+ patients. However, Tz responsive patients often develop resistance to Tz treatment. Herein, redox selenides (RSe-) were covalently linked to Tz using a selenium (Se)-modified Bolton–Hunter Reagent forming Seleno-Trastuzumab (Se-Tz; ~25 µgSe/mg). Se-Tz was compared to Tz and sodium selenite to assess the viability of JIMT-1 and BT-474 cells. Comparative cell viability was examined by microscopy and assessed by fluorometric/enzymatic assays. Se-Tz and selenite redox cycle producing superoxide (O₂^•−) are more cytotoxic to Tz resistant JIMT-1 and Tz sensitive BT-474 cells than Tz. The results of conjugating redox selenides to Tz suggest a wider application of this technology to other antibodies and targeting molecules.     

Chitosan-Based Functional Films Integrated with Magnolol: Characterization,Antioxidant and Antimicrobial Activity and Pork Preservation

The aims of this study were to develop the magnolol–chitosan films and study the positive effect of the combination of magnolol and chitosan. The addition of magnolol made the magnolol–chitosan films exhibit higher density (1.06–1.87 g/cm³), but the relatively lower water vapor permeability (12.06–7.36 × 10⁻¹¹·g·m⁻¹·s⁻¹·Pa⁻¹) and water content (16.10–10.64%). The dense and smooth surface and cross-section of magnolol–chitosan films were observed by environmental scanning electron microscopy (ESEM) images. The interaction of magnolol and chitosan was observed by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). After the addition of magnolol, the antioxidant capacity of magnolol–chitosan films was increased from 18.99 to 82.00%, the growth of P. aeruginosa was inhibited and the inhibition percentage of biofilm formation was increased from 30.89 to 86.04%. We further verified that the application of magnolol–chitosan films on chilled pork significantly reduced the increases in pH value, inhibited the growth of microorganisms and extended the shelf life. Results suggest that magnolol had a positive effect on magnolol–chitosan films and could be effectively applied to pork preservation.     

Optimization of Synthesis Parameters for Mesoporous Shell Formation on Magnetic Nanocores and Their Application as Nanocarriers for Docetaxel Cancer Drug

In this work, Fe₃O₄@SiO₂ nanoparticles were coated with mesoporous silica shell by S⁻N⁺I⁻ pathway by using anionic surfactant (S⁻) and co-structure directing agent (N⁺). The role of co-structure directing agent (CSDA) is to assist the electrostatic interaction between negatively charged silica layers and the negatively charged surfactant molecules. Prior to the mesoporous shell formation step, magnetic cores were coated with a dense silica layer to prevent iron oxide cores from leaching into the mother system under any acidic circumstances. However, it was found that both dense and mesoporous coating parameters affect the textural properties of the produced mesoporous silica shell (i.e., surface area, pore volume and shell thickness). The synthesized Fe₃O₄@SiO₂@m-SiO₂ (MCMSS) nanoparticles have been characterized by low-angle X-ray diffraction, transmission electron microscopy (TEM), and N₂ adsorption-desorption analysis, and magnetic properties. The synthesized particles had dense and mesoporous silica shells of 8–37 nm and 26–50 nm, respectively. Furthermore, MCMSS possessed surface area of ca. 259–621 m²·g⁻¹, and pore volume of ca. 0.216–0.443 cc·g⁻¹. MCMSS showed docetaxcel cancer drug storage capacity of 25–33 w/w% and possessed control release from their mesochannels which suggest them as proper nanocarriers for docetaxcel molecules.     

Glyceollins Trigger Anti-Proliferative Effects in Hormone-Dependent Aromatase-Inhibitor-Resistant Breast Cancer Cells through the Induction of Apoptosis

Aromatase inhibitors (AIs) are standard treatment for estrogen-dependent postmenopausal breast tumors; however, resistance develops leading to tumor relapse and metastasis. We previously demonstrated that glyceollin inhibits proliferation, survival, and migration of hormone-independent letrozole-resistant breast cancer. Since many AI-resistant tumors remain hormone-dependent, identifying distinctions between estrogen-receptor-positive (ER+) and ER-negative (ER-) AI-resistant tumor response to therapy is critical. We hypothesize that treating ER+ letrozole-resistant T47D breast cancer cells (T47DaromLR) with a combination of 10 μM glyceollin and 0.5 μM lapatinib (a dual EGFR/HER2 inhibitor) will decrease cell proliferation through induction of apoptosis. The T47DaromLR cells were found to overexpress HER2 and MAPK while maintaining aromatase and ER levels compared to their letrozole-sensitive (T47Darom) counterparts. In the absence of estrogen stimulation, glyceollin ± lapatinib had no effect on the proliferation of the T47Darom cells, while glyceollin treatment caused 46% reduction in the proliferation of T47DaromLR cells, which was further diminished when combined with lapatinib. While neither agent influenced cell migration, glyceollin and lapatinib reduced S and G2/M phase cell entry and exclusively induced apoptosis by 1.29-fold in the T47DaromLR cells. Taken together, these results suggest that glyceollins and lapatinib may have potential as a novel combination therapeutic approach for hormone-dependent, letrozole-resistant tumors.     

Potential Protection Effect of ER Homeostasis of N6-(2-Hydroxyethyl)adenosine Isolated from Cordyceps cicadae in Nonsteroidal Anti-Inflammatory Drug-Stimulated Human Proximal Tubular Cells

Nonsteroidal anti-inflammatory drugs (NSAIDs) belong to a class of universally and commonly used anti-inflammatory analgesics worldwide. A diversity of drawbacks of NSAIDs have been reported including cellular oxidative stress, which in turn triggers the accumulation of unfolded proteins, enhancing endoplasmic reticulum stress, and finally resulting in renal cell damage. Cordyceps cicadae (CC) has been used as a traditional medicine for improving renal function via its anti-inflammatory effects. N⁶-(2-hydroxyethyl)adenosine (HEA), a physiologically active compound, has been reported from CC mycelia (CCM) with anti-inflammatory effects. We hypothesize that HEA could protect human proximal tubular cells (HK–2) from NSAID-mediated effects on differential gene expression at the mRNA and protein levels. To verify this, we first isolated HEA from CCM using Sephadex^® LH–20 column chromatography. The MTT assay revealed HEA to be nontoxic up to 100 µM toward HK–2 cells. The HK–2 cells were pretreated with HEA (10–20 µM) and then insulted with the NSAIDs diclofenac (DCF, 200 µM) and meloxicam (MXC, 400 µM) for 24 h. HEA (20 µM) effectively prevented ER stress by attenuating ROS production (p < 0.001) and gene expression of ATF–6, PERK, IRE1α, CDCFHOP, IL1β, and NFκB within 24 h. Moreover, HEA reversed the increase of GRP78 and CHOP protein expression levels induced by DCF and MXC, and restored the ER homeostasis. These results demonstrated that HEA treatments effectively protect against DCF- and MXC-induced ER stress damage in human proximal tubular cells through regulation of the GRP78/ATF6/PERK/IRE1α/CHOP pathway.     

Foliate-Targeting Quantum Dots-β-Cyclodextrin Nanocarrier for Efficient Delivery of Unsymmetrical Bisacridines to Lung and Prostate Cancer Cells

Targeted drug delivery by nanocarriers molecules can increase the efficiency of cancer treatment. One of the targeting ligands is folic acid (FA), which has a high affinity for the folic acid receptors, which are overexpressed in many cancers. Herein, we describe the preparation of the nanoconjugates containing quantum dots (QDs) and β-cyclodextrin (β-CD) with foliate-targeting properties for the delivery of anticancer compound C-2028. C-2028 was bound to the nanoconjugate via an inclusion complex with β-CD. The effect of using FA in QDs-β-CD(C-2028)-FA nanoconjugates on cytotoxicity, cellular uptake, and the mechanism of internalization in cancer (H460, Du-145, and LNCaP) and normal (MRC-5 and PNT1A) cells was investigated. The QDs-β-CD(C-2028)-FA were characterized using DLS (dynamic light scattering), ZP (zeta potential), quartz crystal microbalance with dissipation (QCM-D), and UV-vis spectroscopy. The conjugation of C-2028 with non-toxic QDs or QDs-β-CD-FA did not change the cytotoxicity of this compound. Confocal microscopy studies proved that the use of FA in nanoconjugates significantly increased the amount of delivered compound, especially to cancer cells. QD_green-β-CD(C-2028)-FA enters the cells through multiple endocytosis pathways in different levels, depending on the cell line. To conclude, the use of FA is a good self-navigating molecule in the QDs platform for drug delivery to cancer cells.     

Simple fabrication of N-doped mesoporous TiO2 nanorods with the enhanced visible light photocatalytic activity

N-doped mesoporous TiO₂ nanorods were fabricated by a modified and facile sol–gel approach without any templates. Ammonium nitrate was used as a raw source of N dopants, which could produce a lot of gasses such as N₂, NO₂, and H₂O in the process of heating samples. These gasses were proved to be vitally important to form the special mesoporous structure. The samples were characterized by the powder X-ray diffraction, X-ray photoelectron spectrometer, nitrogen adsorption isotherms, scanning electron microscopy, transmission electron microscopy, and UV-visible absorption spectra. The average length and the cross section diameter of the as-prepared samples were ca. 1.5 μm and ca. 80 nm, respectively. The photocatalytic activity was evaluated by photodegradation of methylene blue (MB) in aqueous solution. The N-doped mesoporous TiO₂ nanorods showed an excellent photocatalytic activity, which may be attributed to the enlarged surface area (106.4 m² g^-1) and the narrowed band gap (2.05 eV). Besides, the rod-like photocatalyst was found to be easy to recycle.