Isolation of Pro-Osteogenic Compounds from Euptelea polyandra That Reciprocally Regulate Osteoblast and Osteoclast Differentiation.

Plants contain a large number of small-molecule compounds that are useful for targeting human health and in drug discovery. Healthy bone metabolism depends on the balance between bone-forming osteoblast activity and bone-resorbing osteoclast activity. In an ongoing study searching for 22 plant extracts effective against osteoporosis, we found that the crude extract of Euptelea polyandra Sieb. et Zucc (E. polyandra) had osteogenic bioactivity. In this study, we isolated two compounds, isoquercitrin (1) and astragalin (2), responsible for osteogenic bioactivity in osteoblastic MC3T3-E1 cells from the leaf of E. polyandra using column chromatography and the spectroscopic technique. This is the first report to isolate astragalin from E. polyandra. Compounds (1) and (2) promoted osteoblast differentiation by increasing alkaline phosphatase (ALP) activity and alizarin red S stain-positive calcium deposition, while simultaneously suppressing tartrate-resistant acid phosphatase (TRAP)-positive osteoclast differentiation in RAW264.7 cells at non-cytotoxic concentrations. Isoquercitrin (1) and astragalin (2) increased the expression of osteoblastic differentiation genes, Osterix, ALP, and Osteoprotegerin in the MC3T3-E1 cells, while suppressing osteoclast differentiation genes, TRAP, Cathepsin K, and MMP 9 in the RAW264.7 cells. These compounds may be ideal targets for the treatment of osteoporosis due to their dual function of promoting bone formation and inhibiting bone resorption.

Potentiation of Anticancer Activity of G2/M Blockers by Mild Hyperthermia.

BACKGROUND/AIM: Hyperthermia (HT), combined with chemotherapy, has been used to treat various types of cancer. This study aimed to investigate the HT-sensitivity of malignant and non-malignant cells, and then evaluate the combination effect of docetaxel (DTX) and a newly synthesized chromone derivative (compound A) with HT. MATERIALS AND METHODS: The number of viable cells was determined using the MTT method. Cell cycle distribution was analyzed using a cell sorter, and DNA fragmentation pattern was detected using agarose gel electrophoresis. RESULTS: Among 12 cultured cells, oral squamous cell carcinoma (OSCC), especially Ca9-22 cells, and myelogenous leukemia cells showed higher sensitivity to HT than lung carcinoma and glioblastoma cell lines, while normal oral cells were the most resistant. Cytotoxicity of DTX on Ca9-22 cells was maximum at 41-42°C and 45~60 min exposure to HT. DXT, compound A, and HT induced G2/M arrest of Ca-22 cells. Mild HT enhanced the DTX- and compound A-induced subG1 arrest, in a synergistic fashion. CONCLUSION: The combination G2/M blockers and mild-HT can potentially be used for the treatment of OSCC.

A Comparative Study of Tumor-Specificity and Neurotoxicity between 3-Styrylchromones and Anti-Cancer Drugs.

Background. Many anti-cancer drugs used in clinical practice cause adverse events such as oral mucositis, neurotoxicity, and extravascular leakage. We have reported that two 3-styrylchromone derivatives, 7-methoxy-3-[(1E)-2-phenylethenyl]-4H-1-benzopyran-4-one (Compound A) and 3-[(1E)-2-(4-hydroxyphenyl)ethenyl]-7-methoxy-4H-1-benzopyran-4-one (Compound B), showed the highest tumor-specificity against human oral squamous cell carcinoma (OSCC) cell lines among 291 related compounds. After confirming their superiority by comparing their tumor specificity with newly synthesized 65 derivatives, we investigated the neurotoxicity of these compounds in comparison with four popular anti-cancer drugs. Methods: Tumor-specificity (TSM, TSE, TSN) was evaluated as the ratio of mean CC50 for human normal oral mesenchymal (gingival fibroblast, pulp cell), oral epithelial cells (gingival epithelial progenitor), and neuronal cells (PC-12, SH-SY5Y, LY-PPB6, differentiated PC-12) to OSCC cells (Ca9-22, HSC-2), respectively. Results: Compounds A and B showed one order of magnitude higher TSM than newly synthesized derivatives, confirming its prominent tumor-specificity. Docetaxel showed one order of magnitude higher TSM, but two orders of magnitude lower TSE than Compounds A and B. Compounds A and B showed higher TSM, TSE, and TSN values than doxorubicin, 5-FU, and cisplatin, damaging OSCC cells at concentrations that do not affect the viability of normal epithelial and neuronal cells. QSAR prediction based on the Tox21 database suggested that Compounds A and B may inhibit the signaling pathway of estrogen-related receptors.

CC chemokine ligand 20 (CCL20) positively regulates collagen type I production in 3D skin equivalent tissues.

Chemokines are a group of small proteins that induce chemoattraction and inflammation and contribute to the differentiation and homeostasis of various cell types. Here we explored the role of chemokines, extracellular matrix production, and myofibroblast differentiation in self-assembled skin equivalents (SASE), a three-dimensional (3D) skin-equivalent tissue model. We found that the expression of three chemokines, C-C motif chemokine ligand (CCL) 20, C-X-C motif chemokine ligand (CXCL) 5, and CXCL8, increased with differentiation to myofibroblasts. Addition of recombinant CCL20 to human skin fibroblast induced collagen Type I alpha 2 gene expression, but did not affect the expression of alpha smooth muscle actin expression. Conversely, siRNA gene knockdown of CCL20 effectively inhibited the expression of collagen Type I gene and protein. Furthermore, when the CCL20 gene in fibroblasts was knocked down in SASE, collagen Type I synthesis and stromal thickness were decreased. Taken together, these results have indicated the utility of SASE in understanding how cytokines such as CCL20 positively regulate extracellular matrix proteins such as collagen Type I production during myofibroblast differentiation in 3D tissues that mimic human skin.

Soluble triggering receptor expressed on myeloid cells 2 (sTREM2) positively regulates lipopolysaccharide-induced expression of CXC chemokine ligand 10 and 11 in mouse macrophages.

TREM2 (Triggering receptor expressed on myeloid cells 2) is the causative gene for Nasu-Hakola disease, which is characterized by multiple bone cysts and leukoencephalopathy. In addition, mutations in this gene have been found to be correlated with the onset of Alzheimer's disease. TREM2 is an immunoreceptor expressed on dendritic cells, microglia, osteoclasts, and macrophages. TREM2 on the cell membrane is shed by some proteases and released as soluble TREM2 (sTREM2). Meanwhile, several TREM2 ligands have been reported, and lipopolysaccharide (LPS) is one of the candidates. Using RNA interference to examine TREM2-mediated LPS response in macrophages, we identified five chemokines whose expression was induced via TREM2. Furthermore, we showed that LPS-induced expression of CXC-motif chemokine ligand (Cxcl10) and Cxcl11 among the five chemokines was mediated in part through sTREM2. These results suggest that sTREM2 has cytokine-like functions in macrophages.

Investigation of carbonic anhydrase inhibitory effects and cytotoxicities of pyrazole-based hybrids carrying hydrazone and zinc-binding benzenesulfonamide pharmacophores.

Pyrazole-based carbohydrazone hybrids have been considered to be a remarkable class of compounds in pharmaceutical chemistry. Here, we reported bioactivities of 4-(3-(2-(arylidene)hydrazin-1-carbonyl)-5-phenyl-1H-pyrazol-1-yl)benzenesulfonamides (1-27) towards CA isoenzymes (hCA I, hCA II, hCA IX) and human oral squamous cell carcinoma cell line. Compounds 19 (Ki = 10.1 nM, hCA I/hCA IX = 749.6), 22 (Ki = 18.5 nM, hCA I/hCA IX = 429.2), 26 (Ki = 14.5 nM, hCA I/hCA IX = 596.9), 27 (Ki = 21.5 nM, hCA I/hCA IX = 413.1) were more potent and selective inhibitors of cancer-associated hCA IX isoenzyme. Compounds 22 and 26 were also found to be approximately three times more selective hCA IX inhibitors over off-target hCA II at low nanomolar. Compounds 19, 22, 23, 24, and 26 with IC50 of 1.6-1.7 µM showed potent cytotoxicity against human oral squamous cell carcinoma cell line as compared with human gingival fibroblast, producing the tumor-specificity value over 100. This was due to its cytostatic growth inhibition accompanied by a slight but significant dose-dependent increase in cell shrinkage and subG1 cell accumulation and marginal activation of caspase 3 substrates. Bioassay results showed that carbohydrazone-based hybrids could be useful candidates to design novel anticancer compounds and selective carbonic anhydrase inhibitors.

Dichloroacetyl Amides of 3,5-Bis(benzylidene)-4-piperidones Displaying Greater Toxicity to Neoplasms than to Non-Malignant Cells.

A series of 3,5-bis(benzylidene)-1-dichloroacetyl-4-piperidones 1a-l was evaluated against Ca9-22, HSC-2, HSC-3, and HSC-4 squamous cell carcinomas. Virtually all of the compounds displayed potent cytotoxicity, with 83% of the CC50 values being submicromolar and several CC50 values being in the double digit nanomolar range. The compounds were appreciably less toxic to human HGF, HPLF, and HPC non-malignant cells, which led to some noteworthy selectivity index (SI) figures. From these studies, 1d,g,k emerged as the lead molecules in terms of their potencies and SI values. A Quantitative Structure-Activity Relationship (QSAR) study revealed that cytotoxic potencies and potency-selectivity expression figures increased when the magnitude of the sigma values in the aryl rings was elevated. The modes of action of the representative cytotoxins in Ca9-22 cells were found to include G2/M arrest and stimulation of the cells to undergo mitosis and cause poly(ADP-ribose) polymerase (PARP) and procaspase 3 cleavage.

Tumor-Specificity, Neurotoxicity, and Possible Involvement of the Nuclear Receptor Response Pathway of 4,6,8-Trimethyl Azulene Amide Derivatives.

BACKGROUND: Very few papers covering the anticancer activity of azulenes have been reported, as compared with those of antibacterial and anti-inflammatory activity. This led us to investigate the antitumor potential of fifteen 4,6,8-trimethyl azulene amide derivatives against oral malignant cells. METHODS: 4,6,8-Trimethyl azulene amide derivatives were newly synthesized. Anticancer activity was evaluated by tumor-specificity against four human oral squamous cell carcinoma (OSCC) cell lines over three normal oral cells. Neurotoxicity was evaluated by cytotoxicity against three neuronal cell lines over normal oral cells. Apoptosis induction was evaluated by Western blot and cell cycle analyses. RESULTS: Among fifteen derivatives, compounds 7, 9, and 15 showed the highest anticancer activity, and relatively lower neurotoxicity than doxorubicin, 5-fluorouracil (5-FU), and melphalan. They induced the accumulation of a comparable amount of a subG1 population, but slightly lower extent of caspase activation, as compared with actinomycin D, used as an apoptosis inducer. The quantitative structure-activity relationship analysis suggests the significant correlation of tumor-specificity with a 3D shape of molecules, and possible involvement of inflammation and hormone receptor response pathways. CONCLUSIONS: Compounds 7 and 15 can be potential candidates of a lead compound for developing novel anticancer drugs.

Cytotoxic Tumour-Selective 1,5-Diaryl-3-Oxo-1,4-Pentadienes Mounted on a Piperidine Ring.

A series of 3,5-bis(benzylidene)-4-piperidones 2a-u were prepared as candidate cytotoxic agents. In general, the compounds are highly toxic to human gingival carcinoma (Ca9-22), human squamous carcinoma-2 (HSC-2) and human squamous carcinoma-4 (HSC-4) neoplasms, but less so towards non-malignant human gingival fibroblast (HGF), human periodontal ligament fibroblast (HPLF) and human pulp cells (HPC), thereby demonstrating tumour-selective toxicity. A further study revealed that most of the compounds in series 2 were more toxic to the human Colo-205 adenocarcinoma cell line (Colo-205), human HT29 colorectal adenocarcinoma cells (HT-29) and human CEM lymphoid cells (CEM) neoplasms than towards non-malignant human foreskin Hs27 fibroblast line (Hs27) cells. The potency of the cytotoxins towards the six malignant cell lines increased as the sigma and sigma star values of the aryl substituents rose. Attempts to condense various aryl aldehydes with 2,2,6,6-tetramethyl-4-piperidone led to the isolation of some 1,5-diaryl-1,4-pentadien-3-ones. The highest specificity for oral cancer cells was displayed by 2e and 2r. In the case of 2r, its selective toxicity exceeded that of doxorubicin and melphalan. The enones 2k, m, o have the highest SI values towards colon cancer and leukemic cells. Both 2e,r inhibited mitosis and increased the subG1 population (with a transient increase in G2/M phase cells). Slight activation of caspase-3, based on the cleavage of poly(ADP-ribose)polymerase (PARP) and procaspase 3, was detected.

Purification and Biological Function of Caldecrin.

Blood calcium homeostasis is critical for biological function. Caldecrin, or chymotrypsin-like elastase, was originally identified in the pancreas as a serum calcium-decreasing factor. The serum calcium-decreasing activity of caldecrin requires the trypsin-mediated activation of the protein. Protease activity-deficient mature caldecrin can also reduce serum calcium concentration, indicating that structural processing is necessary for serum calcium-decreasing activity. Caldecrin suppresses the differentiation of bone-resorbing osteoclasts from bone marrow macrophages (BMMs) by inhibiting receptor activator of NF-κB ligand (RANKL)-induced nuclear factor of activated T-cell cytoplasmic 1 expression via the Syk-PLCγ-Ca2+ oscillation-calcineurin signaling pathway. It also suppresses mature osteoclastic bone resorption by RANKL-stimulated TRAF6-c-Src-Syk-calcium entry and actin ring formation. Caldecrin inhibits lipopolysaccharide (LPS)-induced osteoclast formation in RANKL-primed BMMs by inducing the NF-κB negative regulator A20. In addition, caldecrin suppresses LPS-mediated M1 macrophage polarization through the immunoreceptor triggering receptor expressed on myeloid cells (TREM) 2, suggesting that caldecrin may function as an anti-osteoclastogenic and anti-inflammatory factor via TREM2. The ectopic intramuscular expression of caldecrin cDNA prevents bone resorption in ovariectomized mice, and the administration of caldecrin protein also prevents skeletal muscle destruction in dystrophic mice. In vivo and in vitro studies have indicated that caldecrin is a unique multifunctional protease and a possible therapeutic target for skeletal and inflammatory diseases.

Feiyanning Formula Induces Apoptosis of Lung Adenocarcinoma Cells by Activating the Mitochondrial Pathway.

Feiyanning formula (FYN) is a traditional Chinese medicine (TCM) prescription used for more than 20 years in the treatment of lung cancer. FYN is composed of Astragalus membranaceus, Polygonatum sibiricum, Atractylodes macrocephala, Cornus officinalis, Paris polyphylla, and Polistes olivaceous, etc. All of them have been proved to have anti-tumor effect. In this study, we used the TCM network pharmacological analysis to perform the collection of compound and disease target, the prediction of compound target and biological signal and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. It was found that the activation of mitochondrial pathway might be the molecular mechanism of the anti-lung cancer effect of FYN. The experimental results showed that FYN had an inhibitory effect on the growth of lung cancer cells in a dose-dependent and time-dependent manner. Moreover, FYN induced G2/M cell cycle arrest and apoptotic cell death as early as 6 h after treatment. In addition, FYN significantly induced mitochondrial membrane depolarization and increased calreticulin expression. Metabolomics analysis showed the increase of ATP utilization (assessed by a significant increase of the AMP/ATP and ADP/ATP ratio, necessary for apoptosis induction) and decrease of polyamines (that reflects growth potential). Taken together, our study suggested that FYN induced apoptosis of lung adenocarcinoma cells by promoting metabolism and changing the mitochondrial membrane potential, further supporting the validity of network pharmacological prediction.

Antitumor Effects and Tumor-specificity of Guaiazulene-3-Carboxylate Derivatives Against Oral Squamous Cell Carcinoma In Vitro.

AIM: The aim of this study was to investigate the antitumor potential of guaiazulene-3-carboxylate derivatives against oral malignant cells. MATERIALS AND METHODS: Twelve guaiazulene-3-carboxylate derivatives were synthesized by introduction of either with alkyl group [1-5], alkoxy group [6, 7], hydroxyl group [8, 9] or primary amine [10-12] at the end of sidechains. Tumor-specificity (TS) was calculated by the ratio of mean 50% cytotoxic concentration (CC50) against 3 human oral mesenchymal cell lines to that against 4 human oral squamous cell carcinoma (OSCC) cell lines. Potency-selectivity expression (PSE) was calculated by dividing TS value by CC50value against OSCC cell lines. Cell cycle analysis was performed by cell sorter. RESULTS: [6, 7] showed the highest TS and PSE values, and induced the accumulation of both subG1 and G2/M cell populations in HSC-2 OSCC cells. Quantitative structure-activity relationship analysis demonstrated that their tumor-specificity was correlated with chemical descriptors that explain the 3D shape, electric state and ionization potential. CONCLUSION: Alkoxyl guaiazulene-3-carboxylates [6, 7] can be potential candidates of lead compound for developing novel anticancer drugs.

Biological Properties of the Aggregated Form of Chitosan Magnetic Nanoparticle.

BACKGROUND/AIM: Chitosan-coated iron oxide nanoparticles (Chi-NP) have gained attention because of their biocompatibility, biodegradability, low toxicity and targetability under magnetic field. In this study, we investigated various biological properties of Chi-NP. MATERIALS AND METHODS: Chi-NP was prepared by mixing magnetic NP with chitosan FL-80. Particle size was determined by scanning and transmission electron microscopes, cell viability by MTT assay, cell cycle distribution by cell sorter, synergism with anticancer drugs by combination index, PGE2 production in human gingival fibroblast was assayed by ELISA. RESULTS: The synthetic process of Chi-NP from FL-80 and magnetic NP increased the affinity to cells, up to the level attained by nanofibers. Upon contact with the culture medium, Chi-NP instantly formed aggregates and interfered with intracellular uptake. Aggregated Chi-NP did not show cytotoxicity, synergism with anticancer drugs, induce apoptosis (accumulation of subG1 cell population), protect the cells from X-ray-induced damage, nor affected both basal and IL-1ß-induced PGE2 production. CONCLUSION: Chi-NP is biologically inert and shows high affinity to cells, further confirming its superiority as a scaffold for drug delivery.

Protection of Bortezomib-induced Neurotoxicity by Antioxidants.

BACKGROUND/AIM: Although chemotherapy agents, such as oxaliplatin, cisplatin, paclitaxel and bortezomib frequently cause severe peripheral neuropathy, very few studies have reported the effective strategy to prevent this side effect. In this study, we first investigated whether these drugs show higher neuropathy compared to a set of 15 other anticancer drugs, and then whether antioxidants, such as sodium ascorbate, N-acetyl-L-cysteine, and vitamin B12 have any protective effect against them. MATERIALS AND METHODS: Rat PC12 cells were induced to differentiate into neuronal cells by repeated overlay of serum-free medium supplemented with nerve growth factor. The cytotoxic levels of anticancer drugs against four human oral squamous cell carcinoma cell lines, three normal oral cells, and undifferentiated and differentiated PC12 cells were determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. Cells were sorted for apoptotic cells (distributed into subG1 phase) and cells at different stages of cell cycle (G1, S and G2/M). RESULTS: All 19 anticancer drugs showed higher cytotoxicity against PC12 compared to oral normal cells. Among them, bortezomib showed the highest cytotoxicity against both undifferentiated and differentiated PC12 cell and, committed them to undergo apoptosis. Sodium ascorbate and N-acetyl-L-cysteine, but not vitamin B12, completely reversed the cytotoxicity of bortezomib. CONCLUSION: Bortezomib-induced neuropathy might be ameliorated by antioxidants.

Glut1 expression is increased by p53 reduction to switch metabolism to glycolysis during osteoblast differentiation.

The glycolytic system is selected for ATP synthesis not only in tumor cells but also in differentiated cells. Differentiated osteoblasts also switch the dominant metabolic pathway to aerobic glycolysis. We found that primary osteoblasts increased expressions of glycolysis-related enzymes such as Glut1, hexokinase 1 and 2, lactate dehydrogenase A and pyruvate kinase M2 during their differentiation. Osteoblast differentiation decreased expression of tumor suppressor p53, which negatively regulates Glut1 expression, and enhanced phosphorylation of AKT, which is regulated by phosphoinositol-3 kinase (PI3K). An inhibitor of PI3K enhanced p53 expression and repressed Glut1 expression. Luciferase reporter assay showed that p53 negatively regulated transcriptional activity of solute carrier family 2 member 1 gene promoter region. Inhibition of glycolysis in osteoblasts reduced ATP contents more significantly than inhibition of oxidative phosphorylation by carbonyl cyanide m-chlorophenyl hydrazine. These results have indicated that osteoblasts increase Glut1 expression through the down-regulation of p53 to switch their metabolic pathway to glycolysis during differentiation.

Caldecrin inhibits lipopolysaccharide-induced pro-inflammatory cytokines and M1 macrophage polarization through the immunoreceptor triggering receptor expressed in myeloid cells-2.

Caldecrin was previously isolated as a serum calcium-decreasing factor from the pancreas and is known to suppress receptor activator of nuclear factor-κB ligand (RANKL)-induced calcium oscillation pathways in osteoclasts. Here, we explored the effects of caldecrin on lipopolysaccharide (LPS)-Toll-like receptor-4 (TLR-4) signaling pathways in macrophages. Caldecrin inhibited the LPS-induced gene expression of pro-inflammatory cytokines and M1 macrophage polarization in mouse bone marrow macrophages and the RAW264.7 mouse macrophage cell line. Next, we focused on triggering receptor expressed in myeloid cells-2 (TREM-2) as a co-receptor common to RANKL receptor and TLR-4, and established Trem2-KO RAW264.7 cells, in which Trem2 gene was deleted using the CRISPR/Cas9 system. Caldecrin-mediated alterations in pro-inflammatory cytokine expression and M1 macrophage polarization were not observed in Trem2-KO RAW264.7 cells. These results suggest that caldecrin is not only an inhibitor of osteoclast activation but also a negative regulator of LPS-induced inflammatory responses, functioning via TREM-2.

Further Quantitative Structure-Cytotoxicity Relationship Analysis of 3-Styrylchromones.

BACKGROUND/AIM: Very few studies are available about the biological activity of 3-styrylchromones. Our previous study demonstrated the importance of methoxy group at 6-position of the chromone ring and hydroxyl group at 4'-position of phenyl group in styryl moiety. As a sequel of this study, we synthesized fourteen compounds that include eight 3-styrylchromones where methoxy group was introduced at 7-position of chromone rings, and then evaluated their tumor-specificity. MATERIALS AND METHODS: Tumor-specificity (TS) was calculated by relative cytotoxicity against human oral squamous cell carcinoma cell lines versus human normal oral cells. Apoptosis induction and growth arrest were monitored by cell-cycle analysis. Quantitative structure-activity relationship analysis of TS was performed with 3,167 chemical descriptors. RESULTS AND DISCUSSION: Two compounds, 7-methoxy-3-[(1E)-2-phenylethenyl]-4H-1-benzopyran-4-one [7] and 3-[(1E)-2-(4-hydroxyphenyl)ethenyl]-7-methoxy-4H-1-benzopyran-4-one [14] showed higher tumor-specificity than doxorubicin and 5-FU, suggesting the importance of methoxy group in 7-position of the chromone ring. These compounds induced the apoptosis and mitotic arrest in HSC-2 cells. The tumor-specificity of 3-styrylchromone derivatives were most correlated with descriptors for molecule shape and electronic charge. The present study suggested that modification by introducing methoxy group at 7-position, instead at 6-position, further increased the tumor-specificity of 3-styrylchromone.

Quantitative Structure-Cytotoxicity Relationship of 2-Arylazolylchromones and 2-Triazolylchromones.

BACKGROUND/AIM: 4H-1-Benzopyran-4-one (chromone), present in various flavonoids as a backbone structure, has been used for the synthesis of anticancer drugs. The study aimed at investigating the cytotoxicity of eight 2-arylazolylchromones and twelve 2-triazolylchromones against four human oral squamous cell carcinoma (OSCC) cell lines and three human normal mesenchymal oral cells, and then performed a quantitative structure-activity relationship (QSAR) analysis. MATERIALS AND METHODS: Cell viability was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. The distribution of cells to various phases of cell cycle was determined by cell cycle analysis. A total of 3,218 physicochemical, structural and quantum chemical features were calculated for QSAR analysis from the most stabilized structure optimized using CORINA. RESULTS: 2-[4-(4-fluorophenyl)-1H-imidazol-1-yl]-4H-1-benzopyran-4-one [6] had the highest tumor-specificity (TS), comparable with that of 5-flurouracil (5-FU) and doxorubicin, inducing cytostatic growth inhibition, accumulation of G2+M phase cells with no cells in the G1 phase. All eight 2-triazolylchromones showed much lower tumor-specificity, confirming our previous finding. Tumor-specificity was also correlated with 3D shape, topological shape, size, ionization potential, and the presence of more than two aromatic rings in the molecule and imidazole ring in the nitrogen-containing heterocyclic ring. CONCLUSION: [6] can be a lead compound for designing anticancer drugs.

Quantitative Structure-Cytotoxicity Relationship of 2-Styrylchromones.

BACKGROUND/AIM: Studies of biological activity of 2-styrylchromone derivatives focusing on antioxidant, anti-inflammatory, antiviral and antitumor activity are limited. In this study, eighteen synthetic 2-styrylchromone derivatives were investigated for their cytotoxicity against human malignant and non-malignant cells, and then subjected to quantitative structure-activity relationship (QSAR) analysis. MATERIALS AND METHODS: Tumor-specificity was calculated by the ratio of mean 50% cytotoxic concentration (CC50) against four normal oral cells to that against oral squamous cell carcinoma cell lines. Induction of apoptosis and growth arrest were evaluated by cell-cycle analysis. For QSAR analysis, 3,117 types of physicochemical, structural, and quantum chemical features were calculated from the most stabilized structure of 2-styrylchromone derivatives. RESULTS: Two 2-styrylchromone derivatives in which a methoxy group was introduced at the 4-position of the benzene ring showed tumor-specificity equivalent to or higher than doxorubicin in TS value. These compounds accumulated the subG1 and G2/M phase cells, suggesting the induction of apoptosis. Their tumor-specificity can be explained mainly by molecular shape and electronic state. CONCLUSION: These findings suggest the applicability of 2-styrylchromone to develop safe and effective anticancer agents as seed compounds.

In Vitro Assessment of Antitumor Potential and Combination Effect of Classical and Molecular-targeted Anticancer Drugs.

BACKGROUND/AIM: The aim of the study was to evaluate the antitumor potential and combination effects of chemotherapeutic drugs. MATERIALS AND METHODS: The cytotoxicity of 20 drip-type classical and molecular-targeted anticancer drugs was examined against 4 human oral squamous cell carcinoma cell lines and 5 human oral normal mesenchymal and epithelial cells. Cell cycle progression was monitored by a cell sorter. Combination effect was evaluated by combination index. RESULTS: Most of the classical anticancer drugs showed much higher antitumor activity than molecular-targeted drugs, except bortezomib. Among 12 classical anticancer drugs, taxanes and gemsitabine showed the highest tumor-specificity (TS) and potency-selectivity expression (PSE) values, whereas platinum analogs showed the least TS value. Combination of two classical or a classical and a molecular-targeted drug showed mostly additive or antagonistic effect. 5-FU and cisplatin did not produce a subG1 population, but induced G2/M or G1/S arrest, regardless of the addition of cetuximab. Cetuximab, nibolumab and bortezomib showed potent keratinocyte toxicity. CONCLUSION: The present TS monitoring system may provide useful information for building up the treatment regimens of anticancer drugs.