Epidermoid Carcinoma Cell Line Research Articles

Wet chemical development of CuO/GO nanocomposites: its augmented antimicrobial, antioxidant, and anticancerous activity

This study employed a bottom-up technique to synthesize copper oxide (CuO) nanoparticles over hydrophilic graphene oxide (GO) nanosheets. The CuO/GO nanocomposite has been prepared using two selected precursors of copper nitrate and citric acid with an intermittent mixing of GO solutions. The synthesized Nanocomposites were characterized using different biophysical techniques like FT-IR, NMR, FE-SEM, and HR-TEM analyses. FT-IR analyses confirm the nanocomposites’ successful formation, which is evident from the functional groups of C=C, C-O, and Cu-C stretching vibrations. Morphological analyses reveal the depositions of CuO nanoparticles over the planar rough GO sheets, which has been elucidated from the FE-SEM and HR-TEM analyses supported by respective EDAX analyses. The antimicrobial activities have been evident from the surface roughness and damages seen from the FE-SEM analyses. The CuO/GO sheets were tested against Gram-positive (e.g., Staphylococcus aureus) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa). It is evident that the intrinsic antibacterial activity of CuO/GO sheets, when combined in equal proportions, elicited a robust antibacterial activity when tested over Gram –ve representative bacteria Escherichia coli. The antioxidant behaviour of synthesized CuO/GO nanocomposite was evaluated by scavenging the free radicals of DPPH and ABTS. Moreover, the cytotoxic activity was also studied against epidermoid carcinoma cell line A-431. A brief mathematical formulation has been proposed in this study to uncover the possibilities of using the nanocomposites as potential drug candidates in theranostic applications in disease treatment and diagnosis. This study would help uncover the electronic properties that play in the nano-scaled system at the material-bio interface, which would aid in designing a sensitive nano-electromechanical device bearing both the therapeutic and diagnostic attributes heralding a new horizon in the health care systems.

Cytotoxic and antibacterial depsidones from the endophytic fungus Chaetomium brasiliense isolated from Thai rice

Four new depsidones, mollicellins V-Y (1-4), together with eight known depsidones (5-12) were isolated from the endophytic fungus, Chaetomium brasiliense, detached from stems of Thai rice. Their structures were determined by extensive spectroscopic methods. Mollicellins X, H, and F (3, 8 and 10) showed potent cytotoxicity against the human oral epidermoid carcinoma (KB) cell line, and mollicellin F (10) also showed a potent cytotoxicity against the human hepatocellular carcinoma (HepG2) cell line. Besides, mollicellin B (11) exhibited cytotoxicity against the colorectal adenocarcinoma (HT-29) cell line. Moreover, most of the isolated depsidones displayed potent antibacterial activity against Gram-positive bacteria, Bacillus cereus and Bacillus subtilis, and several of them showed moderate activity against Methicillin-resistant Staphylococcus aureus (MRSA) and clinical isolates of S. aureus. In addition, a few of them also showed moderate activity against a Gram-negative bacteria Pseudomonas aeruginosa.

Nobiletin-loaded composite penetration enhancer vesicles restore the normal miRNA expression and the chief defence antioxidant levels in skin cancer

Skin cancer is one of the most dangerous diseases, leading to massive losses and high death rates worldwide. Topical delivery of nutraceuticals is considered a suitable approach for efficient and safe treatment of skin cancer. Nobiletin; a flavone occurring in citrus fruits has been reported to inhibit proliferation of carcinogenesis since 1990s, is a promising candidate in this regard. Nobiletin was loaded in various vesicular systems to improve its cytotoxicity against skin cancer. Vesicles were prepared using the thin film hydration method, and characterized for particle size, zeta potential, entrapment efficiency, TEM, ex-vivo skin deposition and physical stability. Nobiletin-loaded composite penetration enhancer vesicles (PEVs) and composite transfersomes exhibited particle size 126.70 ± 11.80 nm, 110.10 ± 0.90 nm, zeta potential + 6.10 ± 0.40 mV, + 9.80 ± 2.60 mV, entrapment efficiency 93.50% ± 3.60, 95.60% ± 1.50 and total skin deposition 95.30% ± 3.40, 100.00% ± 2.80, respectively. These formulations were selected for cytotoxicity study on epidermoid carcinoma cell line (A431). Nobiletin-loaded composite PEVs displayed the lowest IC50 value, thus was selected for the in vivo study, where it restored skin condition in DMBA induced skin carcinogenesis mice, as delineated by histological and immuno-histochemical analysis, biochemical assessment of skin oxidative stress biomarkers, in addition to miRNA21 and miRNA29A. The outcomes confirmed that nobiletin- loaded composite PEVs is an efficient delivery system combating skin cancer.

Halofuginone enhances the anti-tumor effect of ALA-PDT by suppressing NRF2 signaling in cSCC

Background5-aminolevulinic acid-mediated PDT (ALA-PDT) has been used in a variety of skin diseases including cSCC (cutaneous squamous cell carcinoma). Halofuginone (HL) is a less-toxic febrifugine derivative and has inhibitory effects on a variety of cancer cells. For now, there are no published study focusing on the combination use of ALA-PDT with HL to improve clinical efficacy of cSCC. ObjectiveIn this study, we will examine the effectiveness of combined treatment of ALA-PDT and HL in cSCC as well as its underlying mechanism. MethodsThe human epidermoid carcinoma cell line SCL-1 was treated with ALA-PDT or/ and HL, and cell viability, cell migration, ROS production, apoptosis were evaluated by CCK-8, colony formation, scratch assay, DCFH-DA probe, flow cytometry, respectively. The protein expression of NRF2 signaling was examined by western blot. ResultsHL strengthened ALA-PDT's inhibition of SCL-1 cell viability, migration, as well as NRF2 related β-catenin, p-Erk1/2, p-Akt and p-S6K1 expression. Overexpression of NRF2 conferred resistance to co-treatment's effects on c-Myc, Cyclin D1, Bcl-2, as well as cell proliferation. HL also strengthened ALA-PDT's inhibition of tumor volume in cSCC mouse model and elevated ROS generation of ALA-PDT. ConclusionHL enhances the anti-tumor effect of ALA-PDT in vitro and in vivo. HL has the potential to enhance the anti-tumor effect of ALA-PDT in cSCC via inhibiting NRF2 signaling.

Investigation of 3-sulfamoyl coumarins against cancer-related IX and XII isoforms of human carbonic anhydrase as well as cancer cells leads to the discovery of 2-oxo-2H-benzo[h]chromene-3-sulfonamide - A new caspase-activating proapoptotic agent.

Herein we report the synthesis of a set of seventeen 3-sulfonamide substituted coumarin derivatives. Prepared compounds were tested invitro for inhibition of four physiologically relevant isoforms of the metalloenzyme human carbonic anhydrase (hCA, EC 4.2.1.1). Several coumarin sulfonamides displayed low nanomolar KI values against therapeutically relevant hCA II, IX, and XII, whereas they did not potently inhibit hCA I. Some of these compounds exerted a concentration-dependent antiproliferative action toward RT4 human bladder cancer and especially A431 human epidermoid carcinoma cell lines. In the meantime, the viability of non-tumorigenic hTERT immortalized human foreskin fibroblast cell line Bj-5ta was not significantly affected by the obtained derivatives. Interestingly, compound 10q (2-oxo-2H-benzo [h]chromene-3-sulfonamide) showed a profound and selective dose-dependent inhibition of A431cell growth with low nanomolar IC50 values. We demonstrated that 10q possessed a concentration-dependent apoptosis induction activity associated with caspase 3/7 activation in cancer cells. As carbonic anhydrase isoforms in question were not potently inhibited by this compound, its antiproliferative effects likely involve other mechanisms, such as DNA intercalation. Compound 10q clearly represents a viable lead for further development of new-generation anticancer agents.

Assessment of antinuclear antibodies (ANA): National recommendations on behalf of the Croatian society of medical biochemistry and laboratory medicine.

Antinuclear antibodies (ANA) represent a family of autoantibodies targeting ubiquitous cellular constituents and are a hallmark of systemic inflammatory autoimmune rheumatic diseases named connective tissue diseases (CTD). The gold standard method for ANA determination is indirect immunofluorescence (IIF) on the human laryngeal epidermoid carcinoma cell line type 2 substrate (HEp-2), but with increasing demand for ANA testing, novel methods eased for automation emerged, which allows testing by staff less experienced in this specific field of laboratory diagnostic. In 2016 The working group (WG) for laboratory diagnostics of autoimmune diseases as part of the Committee for the Scientific Professional Development of the Croatian Society of Medical Biochemistry and Laboratory Medicine (CSMBLM) published the data of a survey regarding general practice in laboratory diagnostics of autoimmune diseases in Croatia. Results indicated high diversity in the performance of autoantibody testing as well as reporting of the results and indicated the need of creating recommendations for the assessment of ANA that would help harmonize diagnostics of systemic autoimmune rheumatic diseases in Croatia. This document encompasses twenty-seven recommendations for ANA testing created concerning indications for ANA testing, preanalytical, analytical, and postanalytical issues, including rational algorithm and quality control assurance. These recommendations are based on the relevant international recommendations and guidelines for the assessment of ANA testing and relevant literature search and should help to harmonize the approach in ANA testing and clarify differences in interpretation of the results obtained using different methods of determination.

Design, synthesis and biological evaluation of sulfamoylphenyl-quinazoline derivatives as potential EGFR/CAIX dual inhibitors.

Multi-target, especially dual-target, drug design has become a popular research field for cancer treatment. Development of small molecule dual-target inhibitors through hybridization strategy can provide highly potent and selective anticancer agents. In this study, three series of quinazoline derivatives bearing a benzene-sulfonamide moiety were designed and synthesized as dual EGFR/CAIX inhibitors. All the synthesized compounds were evaluated against epidermoid carcinoma (A431) and non-small cell lung cancer (A549 and H1975) cell lines, which displayed weak to potent anticancer activity. In particular, compound 8v emerged as the most potent derivative against mutant-type H1975cells, which exhibited comparable activity to osimertinib. Importantly, 8v exhibited stronger anti-proliferative activity than osimertinib against H1975cells under hypoxic condition. Kinase inhibition studies indicated that 8v showed excellent inhibitory effect on EGFRT790M enzyme, which was 41 times more effective than gefitinib and almost equal to osimertinib. Mechanism studies revealed that 8v exhibited remarkable CAIX inhibitory effect comparable to acetazolamide and significantly inhibited the expression of p-EGFR as well as its downstream p-AKT and p-ERK in H1975cells. Notably, 8v was found to inhibit the expression of CAIX and its upstream HIF-1α in H1975cells under hypoxic condition. Molecular docking was also performed to gain insights into the ligand-binding interactions of 8v inside EGFRWT, EGFRT790M and CAIX binding sites.

Costunolide, a Sesquiterpene Lactone, Suppresses Skin Cancer via Induction of Apoptosis and Blockage of Cell Proliferation.

Costunolide is a naturally occurring sesquiterpene lactone that demonstrates various therapeutic actions such as anti-oxidative, anti-inflammatory, and anti-cancer properties. Costunolide has recently emerged as a potential anti-cancer agent in various types of cancer, including colon, lung, and breast cancer. However, its mode of action in skin cancer remains unclear. To determine the anti-cancer potential of costunolide in skin cancer, human epidermoid carcinoma cell line A431 was treated with costunolide. A lactate dehydrogenase assay showed that costunolide diminished the viability of A431 cells. Apoptotic cells were detected by annexin V/propidium iodide double staining and Terminal deoxynucleotidyl transferase mediated dUTP nick end labeling assay assay, and costunolide induced cell apoptosis via activation of caspase-3 as well as induction of poly-ADP ribose polymerase cleavage in A431 cells. In addition, costunolide elevated the level of the pro-apoptotic protein Bax while lowering the levels of anti-apoptotic proteins, including Bcl-2 and Bcl-xL. To address the inhibitory effect of costunolide on cell proliferation and survival, various signaling pathways, including mitogen-activated protein kinases, signal transducer and activator of transcription 3 (STAT3), nuclear factor κB (NF-κB), and Akt, were investigated. Costunolide activated the p38 and c-Jun N-terminal kinase pathways while suppressing the extracellular signal-regulated kinase (ERK), STAT3, NF-κB, and Akt pathways in A431 cells. Consequently, it was inferred that costunolide suppresses cell proliferation and survival via these signaling pathways. Taken together, our data clearly indicated that costunolide exerts anti-cancer activity in A431 cells by suppressing cell growth via inhibition of proliferation and promotion of apoptosis. Therefore, it may be employed as a potentially tumor-specific candidate in skin cancer treatment.

Four new isoflavones from Derris scandens and their in vitro antiproliferative effects

Four new compounds (derriscandenon D (1), E (2), F (3), G (4)) and six known isoflavones (warangalone (5), millewanin E (6), rhynedlin A (7), 6,8-diprenylgenistein (8), isolupalbigenin (9), isoscandinone (10)) were isolated from the acetone extract of the branches of Derris scandens. These compounds were assayed for cell viability using the human lung carcinoma cell line A549, colorectal carcinoma cell line Colo205, epidermoid carcinoma cell line KB, the human acute lymphoblastic leukaemia cell line NALM-6, and human dermal fibroblasts. Compounds 2 and 3 significantly decreased the viability of KB cells, with IC50 values of 2.7 and 12.9 µM, respectively. In addition, compounds 2 and 3 reduced the mitochondrial membrane potential in KB cells. Compounds 2 and 3 strongly down-regulated the cell viability of cell lines KB and NALM-6, achieving IC50 values of 2.7 and 0.9 µM, respectively, compared with the positive control staurosporine at 1.25 and 0.01 µM, respectively.

Synthesis, Characterization, Antimicrobial and Anticancer Activity of New Bidentate Schiff Base Ligand and their Transition Metal(II) Complexes

The metal(II) complexes were synthesized by addition of corresponding MCl2 (M = Mn2+, Ni2+, Cu2+ and Zn2+) with 1,2-bis(1H-pyrrol-2-ylmethylene)diazane in methanol. The ligand acts as a bidentate as confirmed from the mass, IR, UV, NMR and EPR spectral studies. The Schiff base ligand forms hexa-coordinated complexes having octahedral geometry for Mn(II), Ni(II), Zn(II) and Cu(II) complexes. The metal complexes showed an excellent antimicrobial activity spectrum in vitro against both Gram-negative (Klebsiella pneumoniae and Acinetobacter baumannii), Gram-positive (Staphylococcus aureus and Enterococcus faecalis) and human pathogenic bacteria isolates. To find the binding affinity with protein BSA kinase, for that molecular docking studies were also carried for all the four synthesized metal(II) complexes. The anticancer activity of the synthesized metal(II) complexes was also screened against the three human tumor cell lines MCF7 human breast adenocarcinoma cell line, CaSki human caucasian cervical epidermoid carcinoma and HCT116 human colon cancer cell lines. The present study showed that Zn(II) complex showed potent inhibition by the ratio of 80% as compared to the inhibition in the normal cells (L-6).

Metabolic profile and skin-related bioactivities of Cerioporus squamosus hydromethanolic extract

Abstract. Elkhateeb WA, Daba GM, Elnahas MO, Thomas PW, Emam M. 2020. Metabolic profile and skin-related bioactivities of Cerioporus squamosus hydromethanolic extract. Biodiversitas 21: 4732-4740. Being a functional food capable of showing nutritional as well as medicinal properties have great attention. Mushrooms have been proven as leading targets in this field. For this purpose, the edible mushroom Cerioporus squamosus was investigated in this study to evaluate the in vitro skin-related bioactivities of its hydromethanolic extract in terms of enhancing wound healing, and human skin cancer suppression capabilities. Treatment of fibroblast cells (BJ-1) with the hydromethanolic extract of this mushroom at 50 µg/mL enhanced cell migration rates by 71.7% after 24 h of exposure to the extract. Moreover, the same extract exhibited a promising impact on human skin cancer using an epidermoid carcinoma cell line (A431). The gradual increase in C. squamosus hydromethanolic extract concentration caused gradual decrease in the A431 cell viability and proliferation. Maximum effect on reducing the cell viability was obtained at a concentration of 100 µg/mL, where cell viability was 3.7%, and recorded IC50 was 52.6 µg/mL. The metabolic profile of the extract was analyzed by GC-MS, which was performed on its silylated metabolites. Nineteen compounds were detected including sugar alcohols, amino acids, fatty and organic acids. Promising results of this mushroom extract encourage conducting further steps towards using this mushroom as a functional food showing promising bioactivities.

Topical nanostructured lipid carrier gel of quercetin and resveratrol: Formulation, optimization, in vitro and ex vivo study for the treatment of skin cancer.

The objective of this investigation was to develop dual drug-loaded nanostructured lipid carrier (NLC) gel of quercetin and resveratrol to enhance their disposition in dermal and epidermal layers. The optimization of the lipidic phase, i.e., liquid lipid and solid lipid was done on the basis of the solubility of quercetin & resveratrol in lipids in the preformulation stage. NLC formulation was optimized by central composite rotatable design (CCRD). The NLC formulation contained lipid binary mixture (1.0% w/w) and Cremophor RH40 (5% w/v) as a surfactant and had a particle size of 191nm±5.20, polydispersity index (PDI) of 0.33±0.01, zeta potential (ZP) of -10.00mV±0.30 and entrapment efficiency (EE) of 92.85±0.25% (quercetin), 89.05±0.18% (resveratrol) respectively. The flux and permeability coefficient of quercetin and resveratrol from NLC gel were found to be 14.09µg/cm2/h, 3.70µg/cm2/h and 7.21×10-2cm/h, 4.69×10-2cm/h respectively. Dermatokinetic studies revealed that there was a significant increase in the CSkin max and AUC0-8h in skin treated with NLC gel as compared to skin treated with conventional gel, which was prepared using carbopol 934 (1.5% w/w). Further, all claims of dermatokinetic studies were proved by confocal microscopic (CLMS) studies, which revealed that the disposition of combinatorial NLC gel was higher (~3 folds) as compared to the conventional gel. Furthermore, skin treated with NLC gel and untreated skin were analysed by FTIR and DSC spectra to understand the permeation dynamics of NLC gel. The cytotoxic effect of combinatorial NLC gel and the conventional gel assessed in human epidermoid carcinoma (A431) cell line by MTT assay, revealed that IC50 of NLC gel and the conventional gel was 86.50µM and 123.64µM respectively. Thus, these results disclosed that NLC gel could be used as a potential carrier for the delivery of quercetin & resveratrol into deeper layers of the skin and can serve as a promising formulation for treatment of skin cancer.

Low-frequency mechanical vibration induces apoptosis of A431 epidermoid carcinoma cells.

Cancer research is increasingly focused on discovering strategies to induce cancer cell apoptosis without affecting surrounding normal cells. One potential biocompatible method is mechanical vibration, which has been developed as part of the emerging field of mechanomedicine. Previous studies of mechanical vibration have employed high‐frequency vibration, which damages healthy cells. In this study, we examined the effects of brief (1 h) low‐frequency (20 Hz) mechanical vibration on glucose consumption and survival (apoptosis, necrosis, HMGB1 release) of the human epidermoid carcinoma cell line A431. We found that apoptosis, but not necrosis, was significantly increased at 48 h after mechanical vibration compared with cells maintained in static culture. In keeping with this, extracellular release of HMGB1, a necrosis marker, was lower in cultures of A431 cells subjected to mechanical vibration compared with control cells. Glucose consumption was increased in the first 24 h after mechanical vibration but returned to control levels before the onset of apoptosis. Although the precise intracellular mechanisms by which low‐frequency mechanical vibration triggers apoptosis of A431 cells is unknown, these results suggest a possible role for metabolic pathways. Mechanical vibration may thus represent a novel application of mechanomedicine to cancer therapy.

Escherichia coli-based synthesis of cadmium sulfide nanoparticles, characterization, antimicrobial and cytotoxicity studies.

The present research describes the synthesis of cadmium sulfide (CdS) nanoparticles from Escherichia coli under the influence of bacterial enzyme sulphate reductase and study on their cytotoxicity for applications in cancer therapy. Escherichia coli cells were used to synthesize CdS nanoparticles under different concentrations of cadmium chloride and sodium sulfide. The morphology of the nanoparticles was analysed using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) was used for elemental analysis of nanoparticles. Fourier-transform infrared spectroscopy analysis (FTIR) was performed to assess the functional groups of the nanoparticles. Crystalline nature of nanoparticles was assessed using powder X-ray diffraction (XRD). Antibacterial studies of CdS nanoparticles were carried out on foodborne pathogens and cytotoxicity studies were carried out on Mus musculus skin melanoma (B16F10) and human epidermoid carcinoma (A431) cell lines. CdS nanoparticle showed more cytotoxic effect on cancer cells compared with standard 5-aminolevulinic acid (5-ALA). The Escherichia coli-synthesized CdS nanoparticles showed highest zone of inhibition in the ratio 4:1 of cadmium chloride and sodium sulfide on all tested bacterial strains. The nanoparticles were also tested for haemolytic activity on RBC cells, which exhibited lower cytotoxicity than sodium dodecyl sulphate which was used as positive control. The cytotoxicity of CdS nanoparticles assessed on A431 cells showed an inhibition of 81.53% at 100μM concentration while the cytotoxicity assessed on B16F10 cells showed an inhibition of 75.71% at 200μM concentration which was much efficient than 5-ALA which showed an inhibition of 31.95% at a concentration against B16F10 cells and 33.45% against A431 cells at a concentration of 1mM. Cadmium sulfide nanoparticles were thus found to be highly toxic on cancer cells compare with standard anticancerous drug 5-ALA.

Multifloroside Suppressing Proliferation and Colony Formation, Inducing S Cell Cycle Arrest, ROS Production, and Increasing MMP in Human Epidermoid Carcinoma Cell Lines A431.

Multifloroside (4), together with 10-hydroxyoleoside 11-methyl ester (1), 10-hydroxyoleoside dimethyl ester (2), and 10-hydroxyligustroside (3), are all secoiridoids, which are naturally occurring compounds that possess a wide range of biological and pharmacological activities. However, the anti-cancer activity of 1–4 has not been evaluated yet. The objective of this work was to study the anti-cancer activities of 1–4 in the human epidermoid carcinoma cell lines A431 and the human non-small cell lung cancer (NSCLC) cell lines A549. The results indicate that 1–4 differ in potency in their ability to inhibit the proliferation of human A431 and A549 cells, and multifloroside (4) display the highest inhibitory activity against A431 cells. The structure-activity relationships suggest that the o-hydroxy-p-hydroxy-phenylethyl group may contribute to the anti-cancer activity against A431 cells. Multifloroside treatment can also inhibit cell colony formation, arrest the cell cycle in the S-phase, increase the levels of reactive-oxygen-species (ROS), and mitochondrial membrane potential (MMP), but it did not significantly induce cell apoptosis at low concentrations. The findings indicated that multifloroside (4) has the tendency to show selective anti-cancer effects in A431 cells, along with suppressing the colony formation, inducing S cell cycle arrest, ROS production, and increasing MMP.

Andrographolide as a Therapeutic Agent Against Breast and Ovarian Cancers.

Andrographolide (ANDR), isolated from Andrographis paniculata, is a medicinal compound effective against infections, inflammatory disorders, and various cancers. In the present study, the effects of ANDR on NFkB (nuclear factor kappa-light-chain-enhancer of activated B cells) activation, caspase-8-mediated apoptosis and pyroptosis, and extra cellular matrix (ECM) degradation were analyzed in A431, MDA-MB231, and SKOV-3 cell lines. Results showed that ANDR inhibited the growth and proliferation of cancer cell lines by inhibiting NFkB signaling. A significant decrease in phospho-p65 level was observed upon increasing ANDR concentration in epidermoid carcinoma and breast cancer cell lines, A431 and MDA-MB231, respectively. Accordingly, upon ANDR treatment, the expression of caspase-8 was increased, whereas no significant induction of caspase-1 expression was observed. Moreover, we observed a significant increase in the expression of tissue inhibitor of metallopeptidase-1 (TIMP1) upon increasing ANDR concentration. Such induction of TIMP1 inhibited the activity of matrix metallopeptidase-7 (MMP-7), thus preventing the degradation of ECM. Therefore, as ANDR shows cytotoxicity towards cancer cells via the NFkB signal transduction pathway without inducing pyroptosis and blocks breast and ovarian cancer invasion by inhibiting MMP-7 expression through TIMP1 up-regulation, it has the potential to be developed as a drug targeting ovarian and breast cancers.

Discovery and synthesis of 3- and 21-substituted fusidic acid derivatives as reversal agents of P-glycoprotein-mediated multidrug resistance

In this study, we synthesized 23 fusidic acid (FA) derivatives and screened them for tumor drug resistance reversal activity and cytotoxicity toward the KBV (multidrug-resistant oral epidermoid carcinoma) cell line based on MTT assay. Tumor resistance reversal activity of fusidic acid (FA) derivatives was discovered for the first time. Our results showed that compound 1 enhanced the cytotoxicity of paclitaxel toward the drug-resistant KBV cells at a concentration of 5 μM. And compound 1 sensitized KBV cells toward paclitaxel in arresting cells in the G2/M phase and inducing cell apoptosis. Further researches showed that compound 1 inhibited the drug efflux activity of P-glycoprotein (P-gp) by increasing the ATPase activity of P-gp without affecting its expression. The structure-activity relationships (SARs) of the FA derivatives were also preliminarily investigated. Our findings indicate that compound 1 is a promising lead compound for designing FA derivatives with improved tumor drug resistance reversal activity in the future.

Silibinin induced apoptosis of human epidermal cancer A431 cells by promoting mitochondrial NOS

The antitumor effects of silibinin are of increasing interest, though its mechanism is not yet clear. The goal of this study was to clarify the mechanism of silibinin-induced cell death in the A431 human epidermoid carcinoma cell line. We used a cell viability assay, flow cytometry, nitric oxide (NO) assay, and western blotting to examine relationships between silibinin, NO generation and apoptosis in A431 cells. Silibinin inhibited A431 cell growth in a dose-dependent manner, inducing mitochondrial damage, and apoptosis at a high dose. At the same time, high dose silibinin increased NO levels in A431 cells and the endothelial nitric oxide synthase (eNOS) inhibitor NG-nitro-L-arginine methylester (L-NAME) attenuated silibinin-induced cell growth inhibition. By western blotting, silibinin caused increased eNOS phosphorylation in the mitochondria. The AMP-activated protein kinase inhibitor compound C significantly decreased p-eNOS expression, while blocking eNOS did not affect p-AMPK levels, suggested that AMPK acted upstream of eNOS. This study showed that silibinin increased NO levels in A431 cells by activating the AMPK–eNOS pathway, leading to mitochondrial dysfunction and apoptosis. In this mechanism of action, mitochondrial eNOS played an important role. The results provided new understanding of the functions of intracellular NO.

Abstract 2586: Therapeutic potential of the topical treatment of miR-634 ointment for cutaneous squamous cell carcinoma

Abstract Cutaneous squamous cell carcinoma (CSCC) is the second most common nonmelanoma skin cancers. Surgery represents the gold standard for CSCC treatment, however it is needed to develop the noninvasive and effective treatments as the nonsurgical options for CSCC patients whose conditions are not suitable for or who refuse operation. On the other hand, microRNAs (miRs) are endogenous small non-coding RNAs negatively regulate gene expression by interfering with the translation or stability of target transcripts. Some tumor-suppressive miRs can target multiple cancer-promoting genes concurrently and may be useful as a therapeutic agent for cancer therapy. We have previously found that overexpression of miR-634 activated the mitochondrial apoptotic pathway by directly targeting genes associated with cytoprotective processes, including mitochondrial homeostasis, anti-apoptosis, antioxidant ability, and autophagy, in various cancer cells. The development of drug delivery system (DDS) is critical for the implementation of miR-based therapeutics. While topical pharmacotherapy represents a nonsurgical option to consider in CSCC, we validated the therapeutic potential of topical treatment of miR-634 ointment in mice model of CSCC. In xenograft tumors of A431 cells, a human epidermoid carcinoma cell line, in mice the topical treatment of ointment incorporated double-strand miR-634 mimics significantly reduced tumor growth. Furthermore, the topical treatment of miR-634-ointment also inhibited tumor growth in carcinogen-induced mouse skin papilloma model. Taken together, these findings suggest that topical treatment of miR-634-ointment may be useful as a noninvasive and effective treatments for CSCC. Citation Format: Jun Inoue, Kentaro Gokita, Masahiro Kishikawa, Hidetoshi Hamamoto, Katsunori Kobayashi, Kyoko Fujiwara, Takahiro Asakage, Kazuyuki Kojima, Johji Inazawa. Therapeutic potential of the topical treatment of miR-634 ointment for cutaneous squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2586.

Colloidal (-)-epigallocatechin-3-gallate vesicular systems for prevention and treatment of skin cancer: A comprehensive experimental study with preclinical investigation

Skin carcinogenesis is a common malignancy affecting humans worldwide, which could benefit from nutraceuticals as a solution to the drawbacks of conventional skin cancer treatment. (−)-epigallocatechin-3-gallate (EGCG) is a promising nutraceutical in this regard; however, it suffers chemical instability and low bioavailability resulting in inefficient delivery. Therefore, EGCG encapsulation in ultradeformable colloidal vesicular systems, namely: penetration enhancer-containing vesicles (PEVs), ethosomes and transethosomes (TEs) for topical administration has been attempted in this study to overcome the problems associated with the use of free EGCG. The prepared vesicles were characterized for their entrapment efficiency, TEM visualization, chemical compatibility, antioxidant properties, ex-vivo skin deposition, photodegradation and physical stability after storage. Most of the prepared vesicles exhibited reasonable skin deposition and preservation of the inherent antioxidant properties of EGCG with good physical stability. EGCG-loaded PEVs and TEs exhibited an inhibitory effect on epidermoid carcinoma cell line (A431) in addition to reduced tumor sizes in mice, confirmed with histopathological analysis and biochemical quantification of skin oxidative stress biomarkers; glutathione, superoxide dismutase and catalase, as well as lipid peroxidation. EGCG PEVs succeeded in offering an effective delivery system targeting skin cancer, which is worthy of further experimentation.