Dectin-1/SYK Activation Induces Antimicrobial Peptide and Negative Regulator of NF-κB Signaling in Human Oral Epithelial Cells.

BACKGROUND/AIM: Oral epithelial cells serve as the primary defense against microbial exposure in the oral cavity, including the fungus Candida albicans. Dectin-1 is crucial for recognition of ß-glucan in fungi. However, expression and function of Dectin-1 in oral epithelial cells remain unclear. MATERIALS AND METHODS: We assessed Dectin-1 expression in Ca9-22 (gingiva), HSC-2 (mouth), HSC-3 (tongue), and HSC-4 (tongue) human oral epithelial cells using flow cytometry and real-time polymerase chain reaction. Cell treated with ß-glucan-rich zymosan were evaluated using real-time polymerase chain reaction. Phosphorylation of spleen-associated tyrosine kinase (SYK) was analyzed by western blotting. RESULTS: Dectin-1 was expressed in all four cell types, with high expression in Ca9-22 and HSC-2. In Ca9-22 cells, exposure to ß-glucan-rich zymosan did not alter the mRNA expression of chemokines nor of interleukin (IL)6, IL8, IL1ß, IL17A, and IL17F. Zymosan induced the expression of antimicrobial peptides ß-defensin-1 and LL-37, but not S100 calcium-binding protein A8 (S100A8) and S100A9. Furthermore, the expression of cylindromatosis (CYLD), a negative regulator of nuclear factor kappa B (NF-κB) signaling, was induced. In HSC-2 cells, zymosan induced the expression of IL17A. The expression of tumor necrosis factor alpha-induced protein 3 (TNFAIP3), a negative regulator of NF-κB signaling, was also induced. Expression of other cytokines and antimicrobial peptides remained unchanged. Zymosan induced phosphorylation of SYK in Ca9-22 cells, as well as NF-κB. CONCLUSION: Oral epithelial cells express Dectin-1 and recognize ß-glucan, which activates SYK and induces the expression of antimicrobial peptides and negative regulators of NF-κB, potentially maintaining oral homeostasis.

Augmentation of Therapeutic Efficacy of Extraction of Causative Teeth by Irrigation for Odontogenic Maxillary Sinusitis.

BACKGROUND/AIM: Odontogenic maxillary sinusitis is a clinically popular disease, but radical surgery and endoscopic surgery are often required. In the present study, we compared for the first time the therapeutic efficacy of the extraction of causative teeth with or without irrigation of the extraction fossa. PATIENTS AND METHODS: A total of 60 patients underwent extraction of causative tooth. Among them, 34 patients underwent irrigation, while other 26 patients did not. Based on computed tomography (CT) images, treatment efficacy was quantified by the percentage of the remaining maxillary sinus mucosal lesions. The extent of therapeutic efficacy was evaluated following five grades, based on the percentage of remaining lesions: Grade 1 (0%) (disappearance of lesions), Grade 2 (roughly 10%), Grade 3 (roughly 30%), Grade 4 (approximately 50%) and Grade 5 (100%) (no improvement of the lesions). RESULTS: Irrigation significantly augmented the therapeutic efficacy of tooth extraction for maxillary sinus mucosal lesions (mean grade: decreasing from 3.27 to 1.35). CONCLUSION: The combination of tooth extraction and irrigation may contribute to the reduction of the necessity of surgery for the maxillary sinuses.

In vitro cytotoxicity of Withania somnifera (L.) roots and fruits on oral squamous cell carcinoma cell lines: a study supported by flow cytometry, spectral, and computational investigations.

Oral cancer is a severe health problem that accounts for an alarmingly high number of fatalities worldwide. Withania somnifera (L.) Dunal has been extensively studied against various tumor cell lines from different body organs, rarely from the oral cavity. We thus investigated the cytotoxicity of W. somnifera fruits (W-F) and roots (W-R) hydromethanolic extracts and their chromatographic fractions against oral squamous cell carcinoma (OSCC) cell lines [Ca9-22 (derived from gingiva), HSC-2, HSC-3, and HSC-4 (derived from tongue)] and three normal oral mesenchymal cells [human gingival fibroblast (HGF), human periodontal ligament fibroblast (HPLF), and human pulp cells (HPC)] in comparison to standard drugs. The root polar ethyl acetate (W-R EtOAc) and butanol (W-R BuOH) fractions exhibited the strongest cytotoxicity against the Ca9-22 cell line (CC50 = 51.8 and 40.1 µg/mL, respectively), which is relatively the same effect as 5-FU at CC50 = 69.4 µM and melphalan at CC50 = 36.3 µM on the same cancer cell line. Flow cytometric analysis revealed changes in morphology as well as in the cell cycle profile of the W-R EtOAc and W-R BuOH-treated oral cancer Ca9-22 cells compared to the untreated control. The W-R EtOAc (125 µg/mL) exerted morphological changes and induced subG1 accumulation, suggesting apoptotic cell death. A UHPLC MS/MS analysis of the extract enabled the identification of 26 compounds, mainly alkaloids, withanolides, withanosides, and flavonoids. Pharmacophore-based inverse virtual screening proposed that BRD3 and CDK2 are the cancer-relevant targets for the annotated withanolides D (18) and O (12), and the flavonoid kaempferol (11). Molecular modeling studies highlighted the BRD3 and CDK2 as the most probable oncogenic targets of anticancer activity of these molecules. These findings highlight W. somnifera's potential as an affordable source of therapeutic agents for a range of oral malignancies.

Dimeric 3,5-Bis(benzylidene)-4-piperidones: Tumor-Selective Cytotoxicity and Structure-Activity Relationships.

Background: The objective of this study is to find novel antineoplastic agents that display greater toxicity to malignant cells than to neoplasms. In addition, the mechanisms of action of representative compounds are sought. This report describes the cytotoxicity of a number of dimers of 3,5-bis(benzylidene)-4-piperidones against human malignant cells (promyelocytic leukemia HL-60 and squamous cell carcinoma HSC-2, HSC-3, and HSC-4). Methods: Tumor specificity was evaluated by the selectivity index (SI), that is the ratio of the mean CC50 for human non-malignant oral cells (gingival fibroblasts, pulp cells, periodontal ligament fibroblasts) to that for malignant cells. Results: The compounds were highly toxic to human malignant cells. On the other hand, these molecules were less toxic to human non-malignant cells. In particular, a potent lead molecule, 3b, was identified. A QSAR study revealed that the placement of electron-releasing and hydrophilic substituents into the aryl rings led to increases in cytotoxic potencies. The modes of action of a lead compound discovered in this study designated 3b were the activation of caspases-3 and -7, as well as causing PARP1 cleavage and G2 arrest, followed by sub-G1 accumulation in the cell cycle. This compound also depolarized the mitochondrial membrane and generated reactive oxygen species in human colon carcinoma HCT116 cells. In conclusion, this study has revealed that, in general, the compounds described in this report are tumor-selective cytotoxins.

New Megastigmane and Polyphenolic Components of Henna Leaves and Their Tumor-Specific Cytotoxicity on Human Oral Squamous Carcinoma Cell Lines.

Polyphenols have a variety of phenolic hydroxyl and carbonyl functionalities that enable them to scavenge many oxidants, thereby preserving the human redox balance and preventing a number of oxidative stress-related chronic degenerative diseases. In our ongoing investigation of polyphenol-rich plants in search of novel molecules, we resumed the investigation of Lawsonia inermis L. (Lythraceae) or henna, a popular ancient plant with aesthetic and therapeutic benefits. The leaves' 70% aq acetone extract was fractionated on a Diaion HP-20 column with different ratios of H2O/an organic solvent. Multistep gel chromatographic fractionation and HPLC purification of the Diaion 75% aq MeOH and MeOH fractions led to a new compound (1) along with tannin-related metabolites, benzoic acid (2), benzyl 6'-O-galloyl-ß-D-glucopyranoside (3), and ellagic acid (4), which are first isolated from henna. Repeating the procedures on the Diaion 50% aq MeOH eluate led to the first-time isolation of two O-glucosidic ellagitannins, heterophylliin A (5), and gemin D (6), in addition to four known C-glycosidic ellagitannins, lythracin D (7), pedunculagin (8), flosin B (9), and lagerstroemin (10). The compound structures were determined through intensive spectroscopic investigations, including HRESIMS, 1D (1H and 13C) and 2D (1H-1H COSY, HSQC, HMBC, and NOESY) NMR, UV, [α]D, and CD experiments. The new structure of 1 was determined to be a megastigmane glucoside gallate; its biosynthesis from gallic acid and a ß-ionone, a degradative product of the common metabolite ß-carotin, was highlighted. Cytotoxicity investigations of the abundant ellagitannins revealed that lythracin D2 (7) and pedunculagin (8) are obviously more cytotoxic (tumor specificity = 2.3 and 2.8, respectively) toward oral squamous cell carcinoma cell lines (HSC-2, HSC-4, and Ca9-22) than normal human oral cells (HGF, HPC, and HPLF). In summary, Lawsonia inermis is a rich source of anti-oral cancer ellagitannins. Also, the several discovered polyphenolics highlighted here emphasize the numerous biological benefits of henna and encourage further clinical studies to profit from their antioxidant properties against oxidative stress-related disorders.

Cytotoxicity, Differentiation, and Biocompatibility of Root-End Filling: A Comprehensive Study.

Assessing the biocompatibility of endodontic root-end filling materials through cell line responses is both essential and of utmost importance. This study aimed to the cytotoxicity of the type of cell death through apoptosis and autophagy, and odontoblast cell-like differentiation effects of MTA, zinc oxide-eugenol, and two experimental Portland cements modified with bismuth (Portland Bi) and barium (Portland Ba) on primary cell cultures. Material and methods: The cells corresponded to human periodontal ligament and gingival fibroblasts (HPLF, HGF), human pulp cells (HPC), and human squamous carcinoma cells from three different patients (HSC-2, -3, -4). The cements were inoculcated in different concentrations for cytotoxicity evaluation, DNA fragmentation in electrophoresis, apoptosis caspase activation, and autophagy antigen reaction, odontoblast-like cells were differentiated and tested for mineral deposition. The data were subject to a non-parametric test. Results: All cements caused a dose-dependent reduction in cell viability. Contact with zinc oxide-eugenol induced neither DNA fragmentation nor apoptotic caspase-3 activation and autophagy inhibitors (3-methyladenine, bafilomycin). Portland Bi accelerated significantly (p < 0.05) the differentiation of odontoblast-like cells. Within the limitation of this study, it was concluded that Portland cement with bismuth exhibits cytocompatibility and promotes odontoblast-like cell differentiation. This research contributes valuable insights into biocompatibility, suggesting its potential use in endodontic repair and biomimetic remineralization.

UVC-Protective Activity of Lemongrass Among 12 Fat-soluble Herbal Extracts: Rapid Decay Due to Cytotoxicity.

BACKGROUND/AIM: The COVID-19 pandemic led to the rapid spread of the use of ultraviolet C (UVC) sterilizers in many public facilities. Considering the harmful effects of prolonged exposure to UVC, manufacturing of safe skin care products is an important countermeasure. In continuation of our recent study of water-soluble herbal extracts, the present study aimed at searching for anti-UVC components from fat-soluble herbal extracts. MATERIALS AND METHODS: Human dermal fibroblast and melanoma cells were exposed to UVC (1.193 W/m2) for 3 min. Viable cell number was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell-cycle analysis was performed using a cell sorter. UVC-protective activity was quantified by the selective index (SI), i.e., the ratio of the 50% cytotoxic concentration for unirradiated cells to the concentration that restored viability of UVC-treated cells by 50%. RESULTS: Only lemongrass extract, among 12 fat-soluble herbal extracts, showed significant anti-UVC activity, comparable to that of lignified materials and tannins, but exceeding that of N-acetyl-L-cysteine and resveratrol. Lemongrass extract was highly cytotoxic, producing a subG1 cell population. During prolonged incubation in culture medium, the anti-UVC activity of lemongrass extract, sodium ascorbate and vanillic acid declined with an approximate half-life of <0.7, 5.4-21.6, and 27.8-87.0 h, respectively. CONCLUSION: Removal of cytotoxic principle(s) from lemongrass extract is crucial to producing long-lasting UVC-protective effects.

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.

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.

Cancer Chemotherapy-associated Pigmentation of the Oral Mucosa.

BACKGROUND/AIM: Oral adverse events caused by anticancer drugs are diverse, but few reports have examined pigmentation of the oral mucosa. The aim of this study was to clarify the prevalence of oral mucosal pigmentation caused by anticancer drugs. PATIENTS AND METHODS: This single-centre retrospective study investigated patients who underwent oral examination in our hospital during cancer chemotherapy for 3 years from April 1, 2019 to March 31, 2021. Inclusion criteria were patients who could be followed-up for ≥3 months after completing chemotherapy with drugs that caused pigmentation. The primary predictive variable was the cancer chemotherapeutic agent used. The primary outcome variable was pigmentation of the oral mucosa. Collected data were statistically analysed using the χ2 test or Fisher's exact test, with the level of significance set at p<0.05. RESULTS: A total of 388 patients were enrolled in the study. Eleven patients (2.8%) showed oral mucosal pigmentation. Drugs causing pigmentation [deposition rate (number of patients with deposits/users)] were TS-1 (combination of tegafur, gimeracil, and oteracil potassium) [12.2% (5/41)], paclitaxel [4.0% (2/50)], gemcitabine [5.0% (1/20)], cyclophosphamide [2.3% (1/42)], carboplatin [1.6% (1/64)], fluorouracil [2.3% (1/43)], and capecitabine [3.4% (1/29)]. CONCLUSION: Oral pigmentation due to cancer chemotherapy was found in 2.8% of patients. TS-1, carboplatin, cyclophosphamide, capecitabine, fluorouracil, gemcitabine, and paclitaxel caused pigmentation of the oral mucosa. Among these, TS-1 was the most likely to cause pigmentation, affecting 12.2% of users.

Comprehensive Study of Anti-UVC Activity and Cytotoxicity of Hot-water Soluble Herb Extracts.

BACKGROUND/AIM: COVID-19 pandemic caused the rapid dissemination of ultraviolet C (UVC) sterilization apparatuses. Prolonged exposure to UVC, however, may exert harmful effects on the human body. The aim of the present study was to comprehensively investigate the anti-UVC activity of a total of 108 hot-water soluble herb extracts, using human dermal fibroblast and melanoma cell lines, for the future development of skin care products. MATERIALS AND METHODS: Exposure time to UVC was set to 3 min, and cell viability was determined using the MTT assay. Anti-UVC activity was determined using the selective index (SI), a ratio of 50% cytotoxic concentration for unirradiated cells to 50% effective concentration that restored half of the UVC-induced decrease of viability. RESULTS: Dermal fibroblasts at any population doubling level were more resistant to UVC irradiation than melanoma cells. Both 49 herb extracts recommended by Japan Medical Herb Association (JAMHA) and 59 additional herb extracts showed comparable anti-UVC activity. SI values of selected herbs (Butterbur, Cloves, Curry Tree, Evening Primrose, Rooibos, Stevia, Willow) were several-fold lower than those of vitamin C and vanillin. Their potent anti-UVC activity was maintained for at least 6 h post irradiation, but declined thereafter to the basal level, possibly due to cytotoxic ingredients. CONCLUSION: UVC sensitivity may be related to the growth potential of target cells. Removal of cytotoxic ingredients of herb extracts may further potentiate and prolong their anti-UVC activity.

Efficacy of Cryotherapy and Hangeshashinto for Radiation-induced Oral Stomatitis: Preliminary Study.

BACKGROUND/AIM: Radiation-induced stomatitis is one of the main acute disorders in patients with head and neck cancer. Since its treatment is often delayed or discontinued, the control of perioperative oral function is necessary. It has been reported that Hangeshashinto (Japanese traditional herbal medicine) and cryotherapy (known as frozen therapy) alleviate oral stomatitis and the accompanying pain. In the present study, the combination effect of Hangeshashinto and cryotherapy on radiation-induced stomatitis in patients with head and neck cancers was investigated for the first time. PATIENTS AND METHODS: Fifty patients with head and neck cancer were subjected to radiation therapy with concomitant administration of anticancer drugs. They were separated into two groups, matched according to age, stage of cancer progression, total radiation dose, and type of concomitant anticancer drugs. One group was orally administrated frozen Hangeshashinto, while another group was not. Oral mucosal damage was assessed by the grade classification CTCAE v4.0 of the National Cancer Institute of the United States (Japanese JCOG version). Duration time of radiation-induced stomatitis was determined by the appearance of grade 1 redness to its disappearance. RESULTS: Frozen Hangeshashinto significantly alleviated, delayed the onset, and reduced the duration time of the radiation-induced stomatitis. CONCLUSION: Cryotherapy in combination with Hangeshashinto can be used for the treatment of radiation-induced oral stomatitis.

Novel Unsymmetric 3,5-Bis(benzylidene)-4-piperidones That Display Tumor-Selective Toxicity.

Two series of novel unsymmetrical 3,5-bis(benzylidene)-4 piperidones 2a-f and 3a-e were designed as candidate antineoplastic agents. These compounds display potent cytotoxicity towards two colon cancers, as well as several oral squamous cell carcinomas. These compounds are less toxic to various non-malignant cells giving rise to large selectivity index (SI) figures. Many of the compounds are also cytotoxic towards CEM lymphoma and HL-60 leukemia cells. Representative compounds induced apoptotic cell death characterized by caspase-3 activation and subG1 accumulation in some OSCC cells, as well as the depolarization of the mitochondrial membrane potential in CEM cells. A further line of inquiry was directed to finding if the SI values are correlated with the atomic charges on the olefinic carbon atoms. The potential of these compounds as antineoplastic agents was enhanced by an ADME (absorption, distribution, metabolism, and excretion) evaluation of five lead molecules, which revealed no violations.

Prominent Anti-UVC Activity of Lignin Degradation Products.

BACKGROUND/AIM: The rapid spread of COVID-19 resulted in the revision of the value of ultraviolet C (UVC) sterilization in working spaces. This study aimed at re-evaluating the anti-UVC activity of four groups of natural products against human melanoma COLO679 and human normal dermal fibroblast (HDFa) cells, based on chemotherapeutic index. MATERIALS AND METHODS: Various cell lines were exposed to UVC for 3 min in the presence of increasing concentrations of test compounds and viable cell numbers were determined with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The anti-UVC activity was quantified by the ratio of the 50% cytotoxic concentration (determined without irradiation) to the 50% effective concentration (which abolished by 50% the UVC-induced loss of viability). Apoptosis was quantified as the subG1 population proportion following cell-cycle analysis. RESULTS: Among four groups of major natural products, six phenylpropanoids showed the highest anti-UVC activity, followed by the lignified products and alkaline products that contain lignin and its degradation products. On the other hand, tannins and flavonoids showed lower activity due to their higher cytotoxicity. UVC-sensitive COLO679 cells lack dectin-1 protein expression. CONCLUSION: These data suggest the prominent anti-UVC activity of lignin degradation products, and the possible involvement of dectin-1 expression in UVC-sensitivity.

Comparison of UVC Sensitivity and Dectin-2 Expression Between Malignant and Non-malignant Cells.

BACKGROUND/AIM: Rapid spread of COVID-19 resulted in the revision of the value of ultraviolet C (UVC) sterilization in working spaces. This study aimed at investigating the UVC sensitivity of eighteen malignant and nonmalignant cell lines, the protective activity of sodium ascorbate against UVC, and whether Dectin-2 is involved in UVC sensitivity. MATERIALS AND METHODS: Various cell lines were exposed to UVC for 3 min, and cell viability was determined using the MTT assay. Anti-UV activity was determined as the ratio of 50% cytotoxic concentration (determined with unirradiated cells) to 50% effective concentration (that restored half of the UV-induced loss of viability). Dectin-2 expression was quantified using flow cytometry. RESULTS: The use of culture medium rather than phosphate-buffered saline is recommended as irradiation solution, since several cells are easily detached during irradiation in phosphate-buffered saline. Oral squamous cell carcinoma cell lines showed the highest UV sensitivity, followed by neuroblastoma, glioblastoma, leukemia, melanoma, lung carcinoma cells, and normal oral and dermal fibroblasts. Human dermal fibroblasts were more resistant than melanoma cell lines; however, both expressed Dectin-2. Sodium ascorbate at micromolar concentrations eliminated the cytotoxicity of UVC in these cell lines. CONCLUSION: Normal cells are generally UVC-resistant compared to corresponding malignant cells, which have higher growth potential. Dectin-2 protein expression itself may not be determinant of UVC sensitivity.

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.

A Dual Anti-Inflammatory and Anti-Proliferative 3-Styrylchromone Derivative Synergistically Enhances the Anti-Cancer Effects of DNA-Damaging Agents on Colon Cancer Cells by Targeting HMGB1-RAGE-ERK1/2 Signaling.

The current anti-cancer treatments are not enough to eradicate tumors, and therefore, new modalities and strategies are still needed. Most tumors generate an inflammatory tumor microenvironment (TME) and maintain the niche for their development. Because of the critical role of inflammation via high-mobility group box 1 (HMGB1)-receptor for advanced glycation end-products (RAGE) signaling pathway in the TME, a novel compound possessing both anti-cancer and anti-inflammatory activities by suppressing the HMGB1-RAGE axis provides an effective strategy for cancer treatment. A recent work of our group found that some anti-cancer 3-styrylchromones have weak anti-inflammatory activities via the suppression of this axis. In this direction, we searched such anti-cancer molecules possessing potent anti-inflammatory activities and discovered 7-methoxy-3-hydroxy-styrylchromone (C6) having dual suppressive activities. Mechanism-of-action studies revealed that C6 inhibited the increased phosphorylation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) under the stimulation of HMGB1-RAGE signaling and thereby suppressed cytokine production in macrophage-like RAW264.7 cells. On the other hand, in colorectal cancer HCT116 cells, C6 inhibited the activation of ERK1/2, cyclin-dependent kinase 1, and AKT, down-regulated the protein level of XIAP, and up-regulated pro-apoptotic Bax and caspase-3/7 expression. These alterations are suggested to be involved in the C6-induced suppression of cell cycle/proliferation and initiation of apoptosis in the cancer cells. More importantly, in cancer cells, the treatment of C6 potentiates the anti-cancer effects of DNA-damaging agents. Thus, C6 may be a promising lead for the generation of a novel class of cancer therapeutics.

1-[4-(2-Dimethylaminoethoxy)phenylcarbonyl]-3,5-Bis(3,4,5-Trimethoxybenzylidene)- 4-Piperidone Hydrochloride and Related Compounds: Potent Cytotoxins Demonstrate Greater Toxicity to Neoplasms than Non- Malignant Cells.

BACKGROUND: The incidence of cancer has been increasing worldwide. Unfortunately, the drugs used in cancer chemotherapy are toxic to both neoplasms and normal tissues, while many available medications have low potencies. Conjugated α,ß-unsaturated ketones differ structurally from contemporary anticancer medications , some of which have noteworthy antineoplastic properties. OBJECTIVES: This study aimed to design and synthesize highly potent cytotoxins with far greater toxicity to neoplasms than to non-malignant cells. METHODS: A series of N-acyl-3,5-bis(benzylidene)-4-piperidone hydrochlorides 4a-n were prepared and evaluated against Ca9-22, HSC-2, HSC-3, and HSC-4 squamous cell carcinomas as well as against HGF, HPLF, and HPC non-malignant cells. QSAR and western blot analyses were performed. RESULTS: The majority of compounds display submicromolar CC50 values towards the neoplasms; the figures for some of the compounds are below 10-7 M. In general, 4a-n have much lower CC50 values than those of melphalan, 5-fluorouracil, and methotrexate, while some compounds are equitoxic with doxorubicin. The compounds are far less toxic to the non-malignant cells, giving rise to substantial selectivity index (SI) figures. A QSAR study revealed that both potency and the SI data were controlled to a large extent by the electronic properties of the substituents in the arylidene aryl rings. Two representative compounds, 4f and 4g, caused apoptosis in HSC-2 cells. CONCLUSION: The compounds in series 4 are potent cytotoxins displaying tumor-selective toxicity. In particular, 4g with an average CC50 value of 0.04 µM towards four malignant cell lines and a selectivity index of 46.3 is clearly a lead molecule that should be further evaluated.

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.