naphthoquinones has been researched along with Carcinoma--Squamous-Cell* in 42 studies
1 review(s) available for naphthoquinones and Carcinoma--Squamous-Cell
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Pharmacology of antitumor agents from higher plants.
Some pharmacologic properties of nine antitumor agents from higher plants are described. The agents are vincristine, vinblastine the epiodophyllotoxin derivatives VM-26 and VP-16-213, maytansine, bruceantin, thalicarpine, camptothecin, and lapachol. When sufficient information is available, the agents are discussed with regard to their antitumor activity, mechanism of action, pharmacologic disposition, structure-activity relationships, and toxicity. Topics: Animals; Antineoplastic Agents, Phytogenic; Aporphines; Camptothecin; Carcinoma, Squamous Cell; Chemical Phenomena; Chemistry; Etoposide; Humans; Leukemia L1210; Leukemia, Experimental; Leukemia, Lymphoid; Maytansine; Melanoma; Naphthoquinones; Nasopharyngeal Neoplasms; Neoplasms; Neoplasms, Experimental; Phenanthrenes; Structure-Activity Relationship; Teniposide; Vinblastine; Vincristine | 1976 |
41 other study(ies) available for naphthoquinones and Carcinoma--Squamous-Cell
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Induction of S arrest and apoptosis in human oral cancer cells by Rhinacanthin-C extracted from Rhinacanthus nasutus via modulating Akt and p38 signaling pathways.
The search for effective herbal medicines for complementary treatments is on the rise due to the high incidence of recurrence and mortality rate in human oral cancer. Rhinacanthus nasutus KURZ., an annual herb found mostly in Southeast Asia including Thailand, has been wildly used as a traditional folk medicine for the treatment of several diseases including cancer. However, the anti-cancer effect of Rhinacanthin-C (Rh-C) as a major naphthoquinone compound found in R. nasutus and the underlying mechanism of its action on human oral cancer cells remain unknown.. To investigate the anti-cancer mechanism of Rh-C extracted from R. nasutus in human oral cancer cells.. The anti-proliferative effect of Rh-C on human oral squamous cell carcinoma (HSC4) was determined and compared to normal oral cells (human gingival fibroblasts, HGF, and normal oral keratinocytes, NOK) using the SRB colorimetric method. The molecular mechanism of Rh-C was explored using flow cytometry, colorimetric assay, in vitro human topoisomerase II assay, and Western blotting.. Rh-C displayed a time- and concentration-dependent growth inhibition on HSC4 and was much less effective on both tested normal oral cells. Rh-C inhibited Akt phosphorylation whereas over-activated p38 MAPK phosphorylation in HSC4 but not in HGF. Rh-C also inhibited topoisomerase II activity. As a result, the cell cycle was arrested in S-phase as the expression of CDK1/2 and Cyclin A2 was decreased. Eventually, the induction of HSC4 cell apoptosis was mediated by increased caspase 3 activity.. Rh-C isolated from R. nasutus possesses anti-cancer properties on human oral cancer cells by causing the S arrest and the apoptotic induction via modulating Akt/p38 signaling pathways. The results provide molecular bases for further developing Rh-C as a potential drug candidate or a complementary treatment for oral cancer. Topics: Apoptosis; Carcinoma, Squamous Cell; Cell Line, Tumor; Humans; Mouth Neoplasms; Naphthoquinones; Proto-Oncogene Proteins c-akt; Signal Transduction | 2023 |
Deoxyshikonin Mediates Heme Oxygenase-1 Induction and Apoptotic Response via p38 Signaling in Tongue Cancer Cell Lines.
Deoxyshikonin (DSK), a phytochemical constituent, has been documented to elicit various oncostatic properties alone or in combination with established therapeutics. However, its role in restraining oral squamous cell carcinoma (OSCC) is mostly unclear. Here, we examined the tumor-suppressive effect of DSK and explored the molecular mechanisms underlying DSK's activities on controlling oral cancer. Our results showed that DSK dose-dependently lessened the cell viability of tongue cancer cell lines, involving induction of cell cycle arrest at the sub-G1 phase and apoptotic cell death. Moreover, a unique signature of apoptosis-related proteins, including augmented nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) expression and caspase activation, was observed in DSK-treated tongue cancer cell lines. Furthermore, DSK-mediated upregulation of HO-1 and cleavage of caspase-9 and -3 were significantly inhibited by pharmacological blockage of p38 kinase. Collectively, these data revealed that DSK halted cell cycle progression and elicited cell apoptosis in tongue cancer cell lines, reshaping a p38-dependent profile of apoptotic proteome. Our findings provided novel insights into the therapeutic implications of a natural compound on the management of OSCC. Topics: Apoptosis; Apoptosis Regulatory Proteins; Carcinoma, Squamous Cell; Cell Line, Tumor; Heme Oxygenase-1; Humans; Mouth Neoplasms; Naphthoquinones; NF-E2-Related Factor 2; p38 Mitogen-Activated Protein Kinases; Tongue Neoplasms | 2022 |
Pro-Apoptotic Antitumoral Effect of Novel Acridine-Core Naphthoquinone Compounds against Oral Squamous Cell Carcinoma.
Oral squamous cell carcinoma (OSCC) is a global public health problem with high incidence and mortality. The chemotherapeutic agents used in the clinic, alone or in combination, usually lead to important side effects. Thus, the discovery and development of new antineoplastic drugs are essential to improve disease prognosis and reduce toxicity. In the present study, acridine-core naphthoquinone compounds were synthesized and evaluated for their antitumor activity in OSCC cells. The mechanism of action, pharmacokinetics, and toxicity parameters of the most promising compound was further analyzed using in silico, in vitro, and in vivo methods. Among the derivatives, compound Topics: Acridines; Animals; Antineoplastic Agents; Apoptosis; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Proliferation; Head and Neck Neoplasms; Molecular Docking Simulation; Mouth Neoplasms; Naphthoquinones; Squamous Cell Carcinoma of Head and Neck | 2022 |
Chemoselective Synthesis of Mannich Adducts from 1,4-Naphthoquinones and Profile as Autophagic Inducers in Oral Squamous Cell Carcinoma.
Oral squamous cell carcinoma (OSCC) is a worldwide public health problem, accounting for approximately 90% of all oral cancers, and is the eighth most common cancer in men. Cisplatin and carboplatin are the main chemotherapy drugs used in the clinic. However, in addition to their serious side effects, such as damage to the nervous system and kidneys, there is also drug resistance. Thus, the development of new drugs becomes of great importance. Naphthoquinones have been described with antitumor activity. Some of them are found in nature, but semi synthesis has been used as strategy to find new chemical entities for the treatment of cancer. In the present study, we promote a multiple component reaction (MCR) among lawsone, arylaldehydes, and benzylamine to produce sixteen chemoselectively derivated Mannich adducts of 1,4-naphthoquinones in good yield (up to 97%). The antitumor activities and molecular mechanisms of action of these compounds were investigated in OSCC models and the compound 6a induced cytotoxicity in three different tumor cell lines (OSCC4, OSCC9, and OSCC25) and was more selective (IS > 2) for tumor cells than the chemotropic drug carboplatin and the controls lapachol and shikonin, which are chemically similar compounds with cytotoxic effects. The 6a selectively and significantly reduced the amount of cell colony growth, was not hemolytic, and tolerable in mice with no serious side effects at a concentration of 100 mg/kg with a LD50 of 150 mg/kg. The new compound is biologically stable with a profile similar to carboplatin. Morphologically, 6a does not induce cell retraction or membrane blebs, but it does induce intense vesicle formation and late emergence of membrane bubbles. Exploring the mechanism of cell death induction, compound 6a does not induce ROS formation, and cell viability was not affected by inhibitors of apoptosis (ZVAD) and necroptosis (necrostatin 1). Autophagy followed by a late apoptosis process appears to be the death-inducing pathway of 6a, as observed by increased viability by the autophagy inhibitor (3-MA) and by the appearance of autophagosomes, later triggering a process of late apoptosis with the presence of caspase 3/7 and DNA fragmentation. Molecular modeling suggests the ability of the compound to bind to topoisomerase I and II and with greater affinity to hPKM2 enzyme than controls, which could explain the mechanism of cell death by autophagy. Finally, the in-silico prediction of drug-relevant properties showed Topics: Animals; Antineoplastic Agents; Apoptosis; Autophagy; Carboplatin; Carcinoma, Squamous Cell; Cell Line, Tumor; Head and Neck Neoplasms; Mice; Mouth Neoplasms; Naphthoquinones; Squamous Cell Carcinoma of Head and Neck | 2022 |
Commitment toward cell death by activation of autophagy with survivin inhibitor YM155 in two canine squamous cell carcinoma cell lines with high expression of survivin.
Canine squamous cell carcinoma (SCC) is difficult to treat if local therapy is not feasible. Recently, survivin inhibitor YM155 was shown to have growth inhibitory activity on high-survivin-expressing canine SCC cell lines HAPPY and SQ4. Here, the mechanisms underlying the effect of YM155 on these cell lines were investigated. YM155 induced cleavage of poly(ADP-ribose) polymerase (PARP) in HAPPY, but not in SQ4 cells. Analyzing two autophagy markers, the level of microtubule-associated protein 1 light chain 3 (LC3)-II and the LC3-II/LC3-I ratio, indicated that YM155 activates autophagy in both cell lines, and this activation occurs prior to PARP cleavage in HAPPY cells. Moreover, inhibition of autophagic flux by chloroquine almost completely prevented the toxic effect of YM155 in both cell lines. Although there are differences in their eventual cell death type, both cell lines may be committed to cell death by activation of autophagy with YM155. Activation of autophagy is likely to be a key mechanism in the growth-inhibitory effects of YM155 in these lines. These data provide new insights into the cytotoxic mechanism of YM155 in canine SCC cells. Topics: Amebicides; Animals; Antineoplastic Agents; Apoptosis; Autophagy; Biomarkers, Tumor; Carcinoma, Squamous Cell; Cell Death; Cell Line, Tumor; Chloroquine; Dog Diseases; Dogs; Gene Expression Regulation, Neoplastic; Humans; Imidazoles; Inhibitor of Apoptosis Proteins; Naphthoquinones; Survivin | 2021 |
Cytotoxicity mechanisms of plumbagin in drug-resistant tongue squamous cell carcinoma.
To evaluate the inhibitory effect and mechanism of plumbagin (PLB) against drug-resistant tongue squamous cell carcinoma (TSCC), and whether its antitumour effect is not affected by tumour drug resistance.. TSCC sensitive CAL27 cells and drug-resistant CAL27/RE cells were used to study the cytotoxicity and mechanism of PLB in vitro, including CCK-8 analysis, colony formation, DAPI staining, flow cytometry assay, transmission electron microscopy, western blotting assay, autophagy, apoptosis and ROS fluorescent probes. BALB/c nude mice xenograft models were used to study the growth inhibitory effect of PLB in vivo.. The results showed that the cell viability and proliferation inhibition and apoptosis induction abilities of PLB on drug-resistant cells were more obvious than that on sensitive cells. And PLB induced protective autophagy in TSCC cells. Mechanistically, PLB induced apoptosis and autophagy by generating reactive oxygen species to mediate JNK and AKT/mTOR pathways. Finally, the growth inhibitory effect of PLB against drug-resistant TSCC was also confirmed in vivo.. PLB will be a promising anticancer agent to overcome drug-resistant TSCC without being affected by its drug resistance properties. Topics: Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Autophagy; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Proliferation; Cell Survival; Drug Resistance, Neoplasm; Male; Mice, Inbred BALB C; Mice, Nude; Naphthoquinones; Phytotherapy; Plant Extracts; Tongue; Tongue Neoplasms; TOR Serine-Threonine Kinases | 2021 |
Molecular mechanism of action of new 1,4-naphthoquinones tethered to 1,2,3-1H-triazoles with cytotoxic and selective effect against oral squamous cell carcinoma.
The oral squamous cell carcinoma (OSCC) stands out as a public health problem due to its high incidence and low survival rate, despite advances in diagnosis and treatment. Moreover, the most commonly chemotherapeutic agents for OSCC, such as carboplatin and cisplatin, generate important side effects, evidencing the urgency in developing new drugs. Naphthoquinones are an important class of natural products or synthetic compounds with cytotoxic effect demonstrated on different cancer types. In the present study, thirty-five 1,4-naphthoquinones tethered to 1,2,3-1H-triazoles were synthesized and the antitumor activity and molecular mechanisms were evaluated in several assays including in vitro and in vivo models of OSCC and normal oral human cells. Compounds 16a, 16b and 16 g were able to induce cytotoxicity in three different tumor cell lines of human OSCC (SCC4, SCC9 and SCC25) and were more toxic and selective to tumor cells (Selective Index, SI > 2) than classical and chemically similar controls (Carboplatin and Lapachol). Compound 16 g showed the higher SI value. Besides, compounds 16a, 16b and 16 g significantly reduced colony formation of SCC9 cells in the tested concentrations. Hemolytic assay using compounds 16a, 16b and 16 g at high concentrations showed no compound exhibited hemolysis higher than 5%, similar to controls. In vivo acute toxicity study showed that 16 g was the only one, among the three compounds, with no apparent limiting toxic effects on mice in the tested concentrations. Thus, the investigation of cell death mechanisms was conducted with this compound. 16 g does not trigger ROS production nor binds to DNA. On the other hand, compound 16 g induced microtubule disorganization, and molecular modeling studies suggests a potential mechanism of action related to inhibition of topoisomerases and/or hPKM2 activities. Cell morphology, pyknotic nuclei presence, cleaved caspase-3 staining and viability assays using caspase-3 inhibitors demonstrate compound 16 g induced cell death through apoptosis. Among the 35 synthesized triazole naphthoquinones, compound 16 g was the most effective compound against OSCC cells, presenting high cytotoxicity (~35 µM), selectivity (SI ~ 6) and low acute toxicity on animals, and therefore might be considered for future cancer therapy. Topics: Animals; Carcinoma, Squamous Cell; Humans; Mice; Molecular Structure; Mouth Neoplasms; Naphthoquinones; Triazoles | 2020 |
Evaluation of Tumor Cell-Tumor Microenvironment Component Interactions as Potential Predictors of Patient Response to Napabucasin.
Topics: Benzofurans; Cancer-Associated Fibroblasts; Carcinogenesis; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Lineage; Coculture Techniques; Gene Expression Regulation, Neoplastic; Humans; Hypopharyngeal Neoplasms; NAD(P)H Dehydrogenase (Quinone); Naphthoquinones; STAT3 Transcription Factor; Tumor Microenvironment | 2019 |
Plumbagin-mediating GLUT1 suppresses the growth of human tongue squamous cell carcinoma.
The purpose of this study was to investigate the clinical and histopathological characteristics of GLUT1 in human tongue squamous cell carcinoma (TSCC) and the role of plumbagin (PLB)-mediating GLUT1 in the growth of TSCC.. Forty-five cases of TSCC samples were collected and the expression and location of GLUT1 was analyzed. The role and mechanism of PLB meditating GLUT1 in the inhibitory growth of human TSCC cell line CAL27 were investigated in vitro and vivo.. The expression of GLUT1 was observed in all samples of human TSCC by immunohistochemical staining. GLUT1 expression was significantly correlated with lymph node metastasis and clinical stage in TSCC. PLB treatment decreased cell viability and colony formation, and increased cell apoptosis in association with the downregulation of GLUT1 via inhibiting PI3K/Akt pathway in vitro and PLB suppressed tumor growth in correlation with downregulation of GLUT1, compared with control group in vivo.. The findings demonstrated a novel anti-cancer mechanism of PLB, inhibitory TSCC growth via suppressing PI3K/Akt/GLUT1 pathway, which will supply a theoretical basis for PLB to treat TSCC. Topics: Animals; Antineoplastic Agents, Phytogenic; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Proliferation; Female; Glucose Transporter Type 1; Humans; Ki-67 Antigen; Male; Matrix Metalloproteinase 2; Mice; Middle Aged; Naphthoquinones; Platelet Endothelial Cell Adhesion Molecule-1; Tongue Neoplasms; Tumor Stem Cell Assay | 2018 |
Antipyrimidine effects of five different pyrimidine de novo synthesis inhibitors in three head and neck cancer cell lines.
The pyrimidine de novo nucleotide synthesis consists of 6 sequential steps. Various inhibitors against these enzymes have been developed and evaluated in the clinic for their potential anticancer activity: acivicin inhibits carbamoyl-phosphate-synthase-II, N-(phosphonacetyl)-L- aspartate (PALA) inhibits aspartate-transcarbamylase, Brequinar sodium and dichloroallyl-lawsone (DCL) inhibit dihydroorotate-dehydrogenase, and pyrazofurin (PF) inhibits orotate-phosphoribosyltransferase. We compared their growth inhibition against 3 cell lines from head-and-neck-cancer (HEP-2, UMSCC-14B and UMSCC-14C) and related the sensitivity to their effects on nucleotide pools. In all cell lines Brequinar and PF were the most active compounds with IC50 (50% growth inhibition) values between 0.06-0.37 µM, Acivicin was as potent (IC50s 0.26-1 µM), but DCL was 20-31-fold less active. PALA was most inactive (24-128 µM). At equitoxic concentrations, all pure antipyrimidine de novo inhibitors depleted UTP and CTP after 24 hr exposure, which was most pronounced for Brequinar (between 6-10% of UTP left, and 12-36% CTP), followed by DCL and PF, which were almost similar (6-16% UTP and 12-27% CTP), while PALA was the least active compound (10-70% UTP and 13-68% CTP). Acivicin is a multi-target inhibitor of more glutamine requiring enzymes (including GMP synthetase) and no decrease of UTP was found, but a pronounced decrease in GTP (31-72% left). In conclusion, these 5 inhibitors of the pyrimidine de novo nucleotide synthesis varied considerably in their efficacy and effect on pyrimidine nucleotide pools. Inhibitors of DHO-DH were most effective suggesting a primary role of this enzyme in controlling pyrimidine nucleotide pools. Topics: Amides; Antineoplastic Agents; Aspartate Carbamoyltransferase; Aspartic Acid; Biphenyl Compounds; Carbamoyl-Phosphate Synthase (Glutamine-Hydrolyzing); Carcinoma, Squamous Cell; Cell Line, Tumor; Dihydroorotate Dehydrogenase; Head and Neck Neoplasms; Humans; Isoxazoles; Naphthoquinones; Orotate Phosphoribosyltransferase; Oxidoreductases Acting on CH-CH Group Donors; Phosphonoacetic Acid; Purine Nucleotides; Pyrazoles; Pyrimidine Nucleotides; Ribonucleosides; Ribose | 2018 |
Potential cytotoxic and selective effect of new benzo[b]xanthenes against oral squamous cell carcinoma.
The current work shows a new synthetic methodology to obtain 21 naphthoquinones that have been evaluated against oral cavity cancer. The compounds were obtained by a three-component reaction involving lawsone, dimedone and aromatic aldehydes catalyzed by lithium chloride under microwave irradiation to produce families of 1,4- and 1,2-naphthoquinones.. A clonogenic assay was performed on SCC9 cell line cultures with all compounds, revealing five very active compounds. In the 3,4,5-dimethylthiazol-2,5-diphenyltetrazolium bromide cell viability assay using three different cell lines (SCC9, SCC4 and SCC25), 8c had an average IC. Therefore, the xanthene-naphthoquinone derivatives show promising bioactivity for oral cavity cancer treatment. Topics: Animals; Antineoplastic Agents; Carboplatin; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Survival; Erythrocytes; Hemolysis; Humans; Mice; Mouth Neoplasms; Naphthoquinones; NIH 3T3 Cells; Structure-Activity Relationship; Xanthenes | 2018 |
Plumbagin, a natural naphthoquinone, inhibits the growth of esophageal squamous cell carcinoma cells through inactivation of STAT3.
Although plumbagin, a natural naphthoquinone, has exhibited antiproliferative activity in numerous types of cancer, its anticancer potential in esophageal squamous cell carcinoma (ESCC) remains unclear. In the present study, the effect of plumbagin on the growth of ESCC cells was investigated in vitro and in vivo. ESCC cells were treated with plumbagin and tested for cell cycle distribution and apoptosis. The involvement of STAT3 signaling in the effect of plumbagin was examined. The results demonstrated that plumbagin treatment suppressed ESCC cell viability and proliferation, yet normal esophageal epithelial cell viability was not affected. Plumbagin treatment increased the proportion of cells in the G0/G1 phase of the cell cycle and decreased the proportion of cells in the S phase. Furthermore, plumbagin‑treated ESCC cells displayed a significantly greater % of apoptotic cells. Western blot analysis confirmed that plumbagin upregulated tumor protein p53 and cyclin‑dependent kinase inhibitor 1A (also known as p21), while it downregulated cyclin D1, cyclin‑dependent kinase 4, and induced myeloid leukemia cell differentiation protein Mcl‑1. Mechanistically, plumbagin inhibited STAT3 activation, and overexpression of constitutively active STAT3 reversed the plumbagin‑mediated growth suppression in ESCC cells. In vivo studies demonstrated that plumbagin delayed the growth of ESCC xenograft tumors and reduced STAT3 phosphorylation. Overall, plumbagin was demonstrated to target STAT3 signaling and to inhibit the growth of ESCC cells both in vitro and in vivo, suggesting that it may represent a potential anticancer agent for ESCC. Topics: Animals; Apoptosis; Carcinoma, Squamous Cell; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Cell Survival; Esophageal Neoplasms; Esophageal Squamous Cell Carcinoma; G1 Phase; Humans; Mice; Naphthoquinones; Resting Phase, Cell Cycle; STAT3 Transcription Factor; Xenograft Model Antitumor Assays | 2018 |
Canine squamous cell carcinoma cell lines with high expression of survivin are sensitive to survivin inhibitor YM155.
Treatment of unresectable canine squamous cell carcinoma (SCC) remains challenging and new therapeutic strategies are needed. Survivin is a member of the inhibitor of apoptosis protein family and its inhibitor, YM155, is a potential anti-tumour agent. In the present study, 10 canine tumour cell lines (representing eight different tumour types) were screened for sensitivity to YM155; the drug potently inhibited the growth of the HAPPY SCC cell line. The growth inhibitory properties of YM155 were then examined in more detail using a panel of seven SCC cell lines. YM155 inhibited the growth of the cell lines HAPPY and SQ4; in contrast to the other lines in the panel, these two cell lines had high levels of expression of survivin. In HAPPY cells, YM155 inhibited expression of the survivin gene at the transcriptional level. In contrast, YM155 down-regulated survivin at the post-transcriptional level in SQ4 cells. YM155 suppressed cell growth in HAPPY cells, mostly via induction of apoptosis, but this was not the case in SQ4 cells. Two canine SCC cell lines with high cellular expression of survivin were sensitive to YM155. The possible underlying mechanisms of the cytotoxic effect of YM155 in these cell lines were different. One cell line had down-regulation of survivin mRNA and protein expression, associated with induction of apoptotic cell death. The other cell line had post-transcriptional down-regulation of survivin expression and subsequent induction of non-apoptotic cell death. Targeting survivin with YM155 is a potential approach for the treatment of canine SCCs with high expression of survivin. Topics: Animals; Carcinoma, Squamous Cell; Cell Line, Tumor; Dog Diseases; Dogs; Imidazoles; Naphthoquinones; Survivin | 2018 |
YM155 Down-Regulates Survivin and Induces P53 Up-Regulated Modulator of Apoptosis (PUMA)-Dependent in Oral Squamous Cell Carcinoma Cells.
BACKGROUND YM155, which inhibits the anti-apoptotic protein survivin, is known to exert anti-tumor effects in various cancers. However, there were few reports describing the inhibitory effect of YM155 on human oral squamous cell carcinoma (OSCC) cells that highly express survivin. In this study, we investigated the anti-tumor effects of YM155 on OSCC cells and then examined its molecular mechanisms. MATERIAL AND METHODS SCC9 cells of OSCC were treated with series of concentrations of YM155 (0.01, 0.1, 1, and 10 ng/ml) for 6, 12, and 24 h. The effect of YM155 on survival of SCC9 cells was detected by MTT and colony formation assay. Cell apoptosis was detected by flow cytometric analysis and the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) assays. Western blot was used to detect the protein expression of survivin, p53, and PUMA. Caspase-3 activity was measured by cleavage of the caspase-3 substrate. To test the role of PUMA and caspase-3 on YM155-induced apoptosis and growth inhibition, the SCC9 cells was transfected with PUMA siRNA or caspase-3 siRNA or control siRNA for 16 h before YM155 (1 and 10 ng/ml) treatment for 24 h. In addition, we also investigated the effect of YM155 in an in vivo xenograft model. RESULTS Treatment of YM155 efficiently reduced survivin expression and increased PUMA expression and caspase-3 activation in the SCC9 cells. YM155 treatment resulted in 18-86% decrease in cell viability, 10-60% decrease in colony numbers, and 8-40% increase in cell apoptosis (p<0.05 and p<0.01). However, the induction of cell apoptosis growth inhibition was reversed by PUMA siRNA or caspase-3 transfection. In addition, animals treated with YM155 showed more than 60% tumor growth inhibition compared to the controls (p<0.05). CONCLUSIONS YM155 is a potent inhibitor of progression of SCC9 cells, which could be due to attenuation of survivin, and activation of the PUMA/caspase-3 cellular signaling processes. This study suggests that YM155 may be a potential molecular target with therapeutic relevance for the treatment of OSCC. Topics: Animals; Apoptosis; Apoptosis Regulatory Proteins; Carcinoma, Squamous Cell; Caspase 3; Cell Line, Tumor; Cell Proliferation; Cell Survival; Down-Regulation; Head and Neck Neoplasms; Humans; Imidazoles; Inhibitor of Apoptosis Proteins; Mice; Mice, Nude; Mouth Neoplasms; Naphthoquinones; Proto-Oncogene Proteins; Squamous Cell Carcinoma of Head and Neck; Survivin; Transcriptional Activation; Xenograft Model Antitumor Assays | 2017 |
Rapamycin enhances the anti-angiogenesis and anti-proliferation ability of YM155 in oral squamous cell carcinoma.
YM155, a small molecule inhibitor of survivin, has been studied in many tumors. It has been shown that YM155 inhibited oral squamous cell carcinoma through promoting apoptosis and autophagy and inhibiting proliferation. It was found that YM155 also inhibited the oral squamous cell carcinoma-mediated angiogenesis through the inactivation of the mammalian target of rapamycin pathway. Rapamycin, a mammalian target of rapamycin inhibitor, played an important role in the proliferation and angiogenesis of oral squamous cell carcinoma cell lines. In our study, cell proliferation assay, transwell assay, tube formation assay, and western blot assay were used to investigate the synergistic effect of rapamycin on YM155 in oral squamous cell carcinoma. Either in vitro or in vivo, rapamycin and YM155 exerted a synergistic effect on the inhibition of survivin and vascular endothelial growth factor through mammalian target of rapamycin pathway. Overall, our results revealed that low-dose rapamycin strongly promoted the sensitivity of oral squamous cell carcinoma cell lines to YM155. Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Autophagy; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Proliferation; Gene Expression Regulation, Neoplastic; Humans; Imidazoles; Inhibitor of Apoptosis Proteins; Mice; Mouth Neoplasms; Naphthoquinones; Neovascularization, Pathologic; Sirolimus; Survivin; Vascular Endothelial Growth Factor A; Xenograft Model Antitumor Assays | 2017 |
Survivin activates NF‑κB p65 via the IKKβ promoter in esophageal squamous cell carcinoma.
Survivin and transcription factor p65 (NF‑κB p65) participate in the progression of esophageal squamous cell carcinoma (ESCC). However, the mechanism of NF‑κB p65 activation in ESCC remains to be elucidated. The aim of the present study was to investigate the role of survivin in the activation of NF‑κB p65 in ESCC. The expression levels of survivin, NF‑κB p65, inhibitor of nuclear factor κB kinase subunit α (IKKα) and inhibitor of nuclear factor κB kinase subunit β (IKKβ) were detected in ESCC tissue samples. Eca109 and KYSE150 cells were cultured and survivin activity was modulated via transfection with an overexpression plasmid, a small hairpin RNA plasmid and a specific inhibitor. Quantitative reverse transcription-polymerase chain reaction and western blotting assays were conducted to assess the effects of survivin on the expression levels of IKKα, IKKβ and NF‑κB p65. Cell cycle and apoptosis assays were conducted to detect surviving-dependent cellular behavior changes. In addition, the luciferase reporter gene assay and chromatin immunoprecipitation assay were conducted to determine the genomic sites responsible for surviving-induced activation of NF‑κB p65. The present study demonstrated that the expression of survivin is positively correlated with IKKα and IKKβ in ESCC tissues. Survivin affected the mRNA and protein expression levels of IKKα, IKKβ, and NF‑κB p65 in Eca109 and KYSE150 cells. Furthermore, survivin increased the transcriptional activity of the IKKβ promoter and bound to the IKKβ promoter region in the Eca109 cells. Downregulation of survivin arrested the cell cycle at the G2/M phase and induced apoptosis. Results of the present study suggest that survivin activates NF‑κB p65 in Eca109 cells via binding to the IKKβ promoter region and upregulating IKKβ promoter transcriptional activity. Survivin overexpression activates NF‑κB p65, which is important in the acquisition and maintenance of the oncogenic characteristics of ESCC. Topics: Apoptosis; Carcinoma, Squamous Cell; Cell Count; Cell Line, Tumor; Cell Survival; Chromatin Immunoprecipitation; Down-Regulation; Esophageal Neoplasms; Esophageal Squamous Cell Carcinoma; G2 Phase Cell Cycle Checkpoints; Gene Knockdown Techniques; Humans; I-kappa B Kinase; Imidazoles; Inhibitor of Apoptosis Proteins; Naphthoquinones; Promoter Regions, Genetic; Protein Binding; RNA, Small Interfering; Survivin; Transcription Factor RelA; Up-Regulation | 2016 |
Targeting of Survivin Pathways by YM155 Inhibits Cell Death and Invasion in Oral Squamous Cell Carcinoma Cells.
Specific overexpression in cancer cells and evidence of oncogenic functions make Survivin an attractive target in cancer therapy. The small molecule compound YM155 has been described as the first "Survivin suppressant" but molecular mechanisms involved in its biological activity and its clinical potential remain obscure. Survivin protein plays critical roles in oral squamous cell carcinoma (OSCC), suggesting that YM155 would be extremely valuable for OSCC. In this study, we tested our hypothesis whether YM155 could be an effective inhibitor of cell growth, invasion and angiogenesis in oral squamous cell carcinoma (OSCC) cells.. SCC9 and SCC25 were treated with different concentration of YM155 for indicated time. Using MTT assay and flow cytometry analysis to detect cell growth and apoptosis; Using transwell and Wound healing assay to detect migration and invasion; Using reverse transcription-PCR, Western blotting and electrophoretic mobility shift assay for measuring gene and protein expression, and DNA binding activity of NF-x03BA;B.. YM155 inhibited survivin-rich expressed SCC9 cell growth in a dose- and time dependent manner. This was accompanied by increased apoptosis and concomitant attenuation of NF-x03BA;B and downregulation of NF-x03BA;B downstream genes MMP-9, resulting in the inhibition of SCC9 cell migration and invasion in vitro and caused antitumor activity and anti metastasis in vivo. YM155 treatment did not affect cell growth, apoptosis and invasion of surviving-poor expressed SCC25 cells in vitro.. YM155 is a potent inhibitor of progression of SCC9 cells, which could be due to attenuation of survivin signaling processes. Our findings provide evidence showing that YM155 could act as a small molecule survivin inhibitor on survivin-rich expressed SCC9 cells in culture as well as when grown as tumor in a xenograft model. We also suggest that survivin could be further developed as a potential therapeutic agent for the treatment of survivin-rich expressed OSCC. Topics: Animals; Antineoplastic Agents; Apoptosis; Carcinoma, Squamous Cell; Cell Death; Cell Line, Tumor; Cell Movement; Cell Proliferation; Female; Humans; Imidazoles; Inhibitor of Apoptosis Proteins; Mice, SCID; Mouth; Mouth Neoplasms; Naphthoquinones; Neoplasm Invasiveness; NF-kappa B; Signal Transduction; Survivin | 2016 |
Down-regulation of Akt by methanol extracts of Impatiens balsamina L. promotes apoptosis in human oral squamous cell carcinoma cell lines.
The apoptotic activity of methanol extracts of Impatiens balsamina L. (MEIB) and related mechanisms in human oral squamous cell carcinoma (OSCC) cells have been systematically investigated.. The effects of MEIB on human OSCC cell lines were investigated using trypan blue exclusion assay, MTS assay, Western blot, 4'-6-diamidino-2-phenylindole (DAPI) staining, Live/Dead assay, Immunohistochemistry, reverse transcription-polymerase chain reaction, and promoter assay.. MEIB decreased cell viability and induced apoptosis in HSC-4 cells. Higher levels of p-Akt expression were observed in OSCC than in normal oral mucosa (NOM), and it correlated with poor survival of the patients. MEIB dephosphorylated p-Akt and decreased Akt expression through proteasome-dependent degradation. LY294002 (PI3K inhibitor) decreased p-Akt and Akt, resulting in enhancing MEIB-induced apoptosis. MEIB down-regulated the expression level of survivin protein at the transcriptional level and YM155 (survivin inhibitor) decreased survivin, which facilitated MEIB-induced apoptosis. MEIB and LY294002 significantly increased Bax, thereby inducing the conformational change, mitochondrial translocation, and oligomerization. In addition, MEIB-induced growth inhibition and apoptosis in OSC-20, another human OSCC cells were mediated by regulating Akt and it downstream targets, survivin and Bax.. These results suggest that MEIB may serve as a potential drug candidate for the treatment of human OSCC. Topics: Adult; Antineoplastic Agents, Phytogenic; Apoptosis; Carcinoma, Squamous Cell; Cell Line, Tumor; Chromones; Down-Regulation; Head and Neck Neoplasms; Humans; Imidazoles; Impatiens; Methanol; Molar, Third; Morpholines; Mouth Mucosa; Mouth Neoplasms; Naphthoquinones; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Plant Extracts; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Squamous Cell Carcinoma of Head and Neck | 2015 |
Plumbagin suppresses tumor cell growth in oral squamous cell carcinoma cell lines.
Plumbagin (PL), a naturally occurring quinoid, exerts antitumoral effects in diverse types of cancer cells. However, the effect of PL on tumor cell proliferation in oral squamous cell carcinoma (OSCC) remains poorly understood. In this study, we assessed the efficacy of PL, in human OSCC cells.. The effect of PL on the cell growth and apoptosis of OSCC cell lines was evaluated using MTT and Annexin V assays, respectively. The effect of PL on mitochondrial membrane potential loss and reactive oxygen species (ROS) generation was evaluated using flow cytometry analysis.. MTT assay showed that PL dose-dependently suppressed OSCC cell growth, with IC50 values ranging from 3.87 to 14.6 μM. Flow cytometry analysis revealed that PL treatment resulted in a significant decrease in mitochondrial membrane potential and an increase in the number of apoptotic cells. Notably, ROS generation was significantly elevated after PL treatment. Furthermore, a ROS scavenger, N-acetylcysteine (NAC), clearly suppressed the decrease in mitochondrial membrane potential, increase of caspase-3/7 activity, and apoptosis after PL treatment.. This study provides the considerable evidence of the tumor-suppressive effect of PL, thereby highlighting its therapeutic potential for OSCC treatment. Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Carcinoma, Squamous Cell; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Humans; Mouth Neoplasms; Naphthoquinones | 2015 |
Shikonin causes cell-cycle arrest and induces apoptosis by regulating the EGFR-NF-κB signalling pathway in human epidermoid carcinoma A431 cells.
Shikonin, a naphthoquinone pigment isolated from the Chinese herbal Zicao, has been shown to exhibit antioxidant and anticancer effects. In the present study, we investigated the antiproliferative and pro-apoptotic effects of shikonin on A431 cells and explored the underlying molecular mechanisms. In the present study, our results showed that shikonin significantly inhibited the growth of A431 cells in a concentration- and time-dependent manner, and caused cell cycle arrest by upregulation of p21 and p27, and downregulation of cyclins and cyclin-dependent kinases. In addition, shikonin evidently induced apoptosis due to decreasing Bcl-2 expression, increasing Bax expression, activating caspase and inactivating NF-κB, while pretreatment with a pan-caspase inhibitor Z-Asp-CH2-DCB abrogated shikonin-induced apoptosis. Moreover, EGF could significantly increase the NF-κB DNA-binding activity and reversed the shikonin-induced inactivation of NF-κB. As anticipated AG1478 (EGFR inhibitor) and Bay11-7082 (NF-κB inhibitor) blocked EGF-reversed the inactivation of NF-κB induced by shikonin. Our data also showed that EGF could evidently reverse the shikonin-induced decreases in cell viability and increases in apoptosis. Then, the NF-κB inhibitors such as Bay11-7082, SN50, Helenalin and the EGFR inhibitor AG1478 and its downstream inhibitor such as PI3K inhibitor LY294002 and STAT3 inhibitor Stattic dramatically blocked EGF-reversed decreases in cell viability and increases in apoptosis induced by shikonin. Collectively, our findings indicated that shikonin inhibited cell growth and caused cell cycle arrest of the A431 cells through the regulation of apoptosis. Moreover, these effects were mediated at least partially by suppressing the activation of the EGFR-NF-κB signaling pathways. Topics: Apoptosis; Carcinoma, Squamous Cell; Cell Cycle Checkpoints; Cell Line, Tumor; Dose-Response Relationship, Drug; ErbB Receptors; Humans; Naphthoquinones; Neoplasm Proteins; NF-kappa B | 2015 |
Plumbagin induces G2/M arrest, apoptosis, and autophagy via p38 MAPK- and PI3K/Akt/mTOR-mediated pathways in human tongue squamous cell carcinoma cells.
Plumbagin (5-hydroxy-2-methyl-1,4-naphthoquinone; PLB), a naturally occurring naphthoquinone isolated from the roots of Plumbaginaceae plants, has been reported to possess anticancer activities in both in vitro and in vivo studies, but the effect of PLB on tongue squamous cell carcinoma (TSCC) is not fully understood. This study aimed to investigate the effects of PLB on cell cycle distribution, apoptosis, and autophagy, and the underlying mechanisms in the human TSCC cell line SCC25. The results have revealed that PLB exerted potent inducing effects on cell cycle arrest, apoptosis, and autophagy in SCC25 cells. PLB arrested SCC25 cells at the G2/M phase in a concentration- and time-dependent manner with a decrease in the expression level of cell division cycle protein 2 homolog (Cdc2) and cyclin B1 and increase in the expression level of p21 Waf1/Cip1, p27 Kip1, and p53 in SCC25 cells. PLB markedly induced apoptosis and autophagy in SCC25 cells. PLB decreased the expression of the anti-apoptotic proteins B-cell lymphoma 2 (Bcl-2) and B-cell lymphoma-extra large (Bcl-xl) while increasing the expression level of the pro-apoptotic protein Bcl-2-associated X protein (Bax) in SCC25 cells. Furthermore, PLB inhibited phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR), glycogen synthase kinase 3β (GSK3β), and p38 mitogen-activated protein kinase (p38 MAPK) pathways as indicated by the alteration in the ratio of phosphorylation level over total protein expression level, contributing to the autophagy inducing effect. In addition, we found that wortmannin (a PI3K inhibitor) and SB202190 (a selective inhibitor of p38 MAPK) strikingly enhanced PLB-induced autophagy in SCC25 cells, suggesting the involvement of PI3K- and p38 MAPK-mediated signaling pathways. Moreover, PLB induced intracellular reactive oxygen species (ROS) generation and this effect was attenuated by l-glutathione (GSH) and n-acetyl-l-cysteine (NAC). Taken together, these results indicate that PLB promotes cellular apoptosis and autophagy in TSCC cells involving p38 MAPK- and PI3K/Akt/mTOR-mediated pathways with contribution from the GSK3β and ROS-mediated pathways. Topics: Apoptosis; Autophagy; Carcinoma, Squamous Cell; Cell Division; Cell Proliferation; Cell Survival; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; G2 Phase Cell Cycle Checkpoints; Humans; M Phase Cell Cycle Checkpoints; MAP Kinase Signaling System; Molecular Structure; Naphthoquinones; p38 Mitogen-Activated Protein Kinases; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Structure-Activity Relationship; Tongue Neoplasms; TOR Serine-Threonine Kinases; Tumor Cells, Cultured | 2015 |
Downregulation of Sp1 is involved in β-lapachone-induced cell cycle arrest and apoptosis in oral squamous cell carcinoma.
β-lapachone (β-lap) is a naturally occurring quinone obtained from the bark of lapacho tree (Tabebuia avellanedae) with anti-proliferative properties against various cancers. The present study investigated the cell proliferation and apoptosis effect of β-lap on two oral squamous cell carcinoma lines (OSCCs). We carried out a series of 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl-2H-tetrazolium (MTS) assays, 4',6-diamidino-2-phenylindole (DAPI) staining, cell cycle analysis, and western blot analysis to characterize β-lap and its underlying signaling pathway. We demonstrated that β-lap-treated cells significantly reduced cell proliferation but increased DNA condensation and increased sub-G1 population in OSCCs. Particularly, β-lap suppresses activation of transcription factor specificity protein 1 (Sp1) followed by apoptosis in a concentration-dependent manner in OSCCs. Furthermore, β-lap modulated protein expression levels of cell cycle regulatory proteins and apoptosis-related proteins that are known as Sp1 target genes, resulting in apoptosis. Our results collectively indicated that β-lap was able to modulate Sp1 transactivation and induce apoptosis through the regulation of cell cycle and apoptosis-related proteins. Therefore, β-lap may be used in cancer prevention and therapies to improve clinical outcome as an anticancer drug candidate. Topics: Apoptosis; Carcinoma, Squamous Cell; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Dose-Response Relationship, Drug; Down-Regulation; Humans; Mouth Neoplasms; Naphthoquinones; Sp1 Transcription Factor | 2015 |
Dual induction of apoptotic and autophagic cell death by targeting survivin in head neck squamous cell carcinoma.
Survivin is ubiquitously expressed in patients with head neck squamous cell carcinoma (HNSCC) and is associated with poor survival and chemotherapy resistance. Sepantronium bromide (YM155) is a selective survivin suppressant that exhibits potent antitumor activities by inducing apoptosis and autophagy in various types of cancer. However, the curative effects and underlying mechanisms of YM155 in HNSCC remain unclear. This study showed that survivin overexpression positively correlated with p-S6, p-Rb and LAMP2 but negatively correlated with the autophagic marker LC3 in human HNSCC tissues. In vitro studies revealed that YM155 triggered apoptosis of HNSCC cells in mitochondria and death receptor-dependent manner. The treatment also significantly enhanced autophagy by upregulating Beclin1, which led to cell death. YM155 not only downregulated the expression of survivin but also remarkably suppressed the activation of the mTOR signaling pathway in vitro and in vivo. YM155 displayed potent antitumor activities in both CAL27 xenograft and transgenic HNSCC mice models by delaying tumor onset and suppressing tumor growth. Furthermore, YM155 combined with docetaxel promoted tumor regression better than either treatment alone without causing considerable body weight loss in the HNSCC xenograft models. Overall, targeting survivin by YM155 can benefit HNSCC therapy by increasing apoptotic and autophagic cell death, and suppressing prosurvival pathways. Topics: Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Apoptosis Regulatory Proteins; Autophagy; Beclin-1; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Proliferation; Docetaxel; Drug Resistance, Neoplasm; Head and Neck Neoplasms; Humans; Imidazoles; In Situ Nick-End Labeling; Inhibitor of Apoptosis Proteins; Lysosomal-Associated Membrane Protein 2; Membrane Proteins; Mice; Mice, Knockout; Mice, Nude; Microtubule-Associated Proteins; Mitochondria; Naphthoquinones; Phosphorylation; Retinoblastoma Protein; Signal Transduction; Squamous Cell Carcinoma of Head and Neck; Survivin; Tamoxifen; Taxoids; TOR Serine-Threonine Kinases; Xenograft Model Antitumor Assays | 2015 |
YM155, a survivin suppressant, triggers PARP-dependent cell death (parthanatos) and inhibits esophageal squamous-cell carcinoma xenografts in mice.
Here we demonstrated that sepantronium bromide (YM155), a survivin suppressant, inhibited esophageal squamous-cell carcinoma (ESCC) growth in mice bearing human ESCC xenografts without affecting body weight. In cell culture, YM155 decreased survivin levels and caused PARP-1 activation, poly-ADP polymer formation, and AIF translocation from the cytosol to the nucleus. Genetic knockdown of PARP-1 or AIF abrogated YM155-induced parthanatos cell death. Furthermore, FOS, JUN and c-MYC gene transcription, which is stimulated by activated PARP-1, was increased following YM155 treatment. Our data demonstrate that YM155 did not trigger apoptosis, but induced parthanatos, a cell death dependent on PARP-1 hyper-activation, and support clinical development of YM155 in ESCC. Topics: Animals; Blotting, Western; Carcinoma, Squamous Cell; Cell Death; Cell Line, Tumor; Cell Survival; Dose-Response Relationship, Drug; Esophageal Neoplasms; Female; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Humans; Imidazoles; Inhibitor of Apoptosis Proteins; Mice, Nude; Microscopy, Electron, Transmission; Microscopy, Fluorescence; Naphthoquinones; Oligonucleotide Array Sequence Analysis; Poly(ADP-ribose) Polymerases; Reverse Transcriptase Polymerase Chain Reaction; RNA Interference; Survivin; Tumor Burden; Xenograft Model Antitumor Assays | 2015 |
Plumbagin suppresses epithelial to mesenchymal transition and stemness via inhibiting Nrf2-mediated signaling pathway in human tongue squamous cell carcinoma cells.
Tongue squamous cell carcinoma (TSCC) is the most common malignancy in oral and maxillofacial tumors with highly metastatic characteristics. Plumbagin (5-hydroxy-2-methyl-1, 4-naphthoquinone; PLB), a natural naphthoquinone derived from the roots of Plumbaginaceae plants, exhibits various bioactivities, including anticancer effects. However, the potential molecular targets and underlying mechanisms of PLB in the treatment of TSCC remain elusive. This study employed stable isotope labeling by amino acids in cell culture (SILAC)-based quantitative proteomic approach to investigate the molecular interactome of PLB in human TSCC cell line SCC25 and elucidate the molecular mechanisms. The proteomic data indicated that PLB inhibited cell proliferation, activated death receptor-mediated apoptotic pathway, remodeled epithelial adherens junctions pathway, and manipulated nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated oxidative stress response signaling pathway in SCC25 cells with the involvement of a number of key functional proteins. Furthermore, we verified these protein targets using Western blotting assay. The verification results showed that PLB markedly induced cell cycle arrest at G2/M phase and extrinsic apoptosis, and inhibited epithelial to mesenchymal transition (EMT) and stemness in SCC25 cells. Of note, N-acetyl-l-cysteine (NAC) and l-glutathione (GSH) abolished the effects of PLB on cell cycle arrest, apoptosis induction, EMT inhibition, and stemness attenuation in SCC25 cells. Importantly, PLB suppressed the translocation of Nrf2 from cytosol to nucleus, resulting in an inhibition in the expression of downstream targets. Taken together, these results suggest that PLB may act as a promising anticancer compound via inhibiting Nrf2-mediated oxidative stress signaling pathway in SCC25 cells. This study provides a clue to fully identify the molecular targets and decipher the underlying mechanisms of PLB in the treatment of TSCC. Topics: Antineoplastic Agents; Apoptosis; Apoptosis Regulatory Proteins; Carcinoma, Squamous Cell; Cell Cycle Proteins; Cell Line, Tumor; Dose-Response Relationship, Drug; Epithelial-Mesenchymal Transition; G2 Phase Cell Cycle Checkpoints; Head and Neck Neoplasms; Humans; Naphthoquinones; Neoplastic Stem Cells; NF-E2-Related Factor 2; Oxidative Stress; Protein Interaction Maps; Protein Transport; Proteomics; Signal Transduction; Squamous Cell Carcinoma of Head and Neck; Time Factors; Tongue Neoplasms | 2015 |
Small-molecule survivin inhibitor YM155 enhances radiosensitization in esophageal squamous cell carcinoma by the abrogation of G2 checkpoint and suppression of homologous recombination repair.
Survivin is overexpressed in cancer cells and plays a crucial role in apoptosis evasion. YM155, a small-molecule inhibitor of survivin, could enhance the cytotoxicity of various DNA-damaging agents. Here, we evaluated the radiosensitizaion potential of YM155 in human esophageal squamous cell carcinoma (ESCC).. Cell viability was determined by CCK8 assay. The radiosensitization effect of YM155 was evaluated by clonogenic survival and progression of tumor xenograft. Cell cycle progression was determined by flow cytometric analysis. Radiation-induced DNA double strand break (DSB) and homologous recombination repair (HRR) were detected by the staining of γ-H2AX and RAD51, respectively. Expression of survivin and cell cycle regulators was detected by Western blot analysis.. YM155 induced radiosensitization in ESCC cell lines Eca109 and TE13, associated with the abrogation of radiation induced G2/M checkpoint, impaired Rad51 focus formation, and the prolongation of γ-H2AX signaling. G2/M transition markers, including the activation of cyclinB1/Cdc2 kinase and the suppression of Cdc2 Thr14/Tyr15 phosphorylation were induced by YM155 in irradiated cells. The combination of YM155 plus irradiation delayed the growth of ESCC tumor xenografts to a greater extent compared with either treatment modality alone.. Our findings suggest that the abrogation of G2 checkpoint and the inhibition of HRR contribute to radiosensitization by YM155 in ESCC cells. Topics: Animals; Antineoplastic Agents; Blotting, Western; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Survival; Esophageal Neoplasms; Esophageal Squamous Cell Carcinoma; Flow Cytometry; Fluorescent Antibody Technique; G2 Phase Cell Cycle Checkpoints; Humans; Imidazoles; Inhibitor of Apoptosis Proteins; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Naphthoquinones; Radiation-Sensitizing Agents; Recombinational DNA Repair; Survivin; Xenograft Model Antitumor Assays | 2014 |
Furano-1,2-Naphthoquinone Inhibits Src and PI3K/Akt Signaling Pathways in Ca9-22 Human Oral Squamous Carcinoma Cells.
Furano-1,2-naphthoquinone (FNQ), a biologically active component ofAvicennia marina, has been demonstrated to display anticancer activity. FNQ exerted cytotoxicity with the G2/M cell cycle arrest and apoptosis in Ca9-22 cells. FNQ-induced G2/M arrest was correlated with a marked decrease in the expression levels of cyclin A and cyclin B, and their activating partner cyclin-dependent kinases (CDK) 1 and 2 with concomitant induction of p27. FNQ-induced apoptosis was accompanied by Bax and Bad upregulation, and the downregulation of Bcl-2, Bcl-XL, Mcl-1, and X-linked inhibitor of apoptosis (XIAP), resulting in cytochrome C release and sequential activation of caspase-9 and caspase-3. Mechanistic studies showed that FNQ suppressed Src phosphorylation, PI3K, and Akt activation in Ca9-22 cells. Moreover, the Src inhibitor PP2 reduced the phosphorylation of Src and activation of PI3K/Akt, which was comparable with FNQ treatment. The combined treatment of FNQ with PP2 enhanced the cell cycle arrest and apoptosis and also led to the downregulation of Bcl-XL, Mcl-1, XIAP, cyclin A, cyclin B, CDK1, and CDK2 and upregulation of p27, Bax, and Bad. These findings suggest that FNQ-mediated cytotoxicity of Ca9-22 cells is related with the G2/M cell cycle arrest and apoptosis via inactivation of Src and PI3K/Akt-mediated signaling pathways. Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Avicennia; Carcinoma, Squamous Cell; Caspase 3; Caspase 9; Cell Line, Tumor; Furans; G2 Phase Cell Cycle Checkpoints; Humans; M Phase Cell Cycle Checkpoints; Mouth Neoplasms; Naphthoquinones; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Pyrimidines; Signal Transduction; src-Family Kinases | 2014 |
Plumbagin (5-hydroxy-2-methyl-1,4-naphthoquinone), isolated from Plumbago zeylanica, inhibits ultraviolet radiation-induced development of squamous cell carcinomas.
Plumbagin (PL) (5-hydroxy-2-methyl-1,4-napthoquinone), a medicinal plant-derived naphthoquinone, was isolated from the roots of the Plumbago zeylanica L. (also known as Chitrak). The roots of P. zeylanica L. have been used in Indian medicine for >2500 years as an anti-atherogenic, cardiotonic, hepatoprotective and neuroprotective agent. We present here that topical application of non-toxic doses (100-500 nmol) of PL to skin elicits dose-dependent inhibition of ultraviolet radiation (UVR)-induced development of squamous cell carcinomas (SCC). In this experiment, FVB/N mice were exposed to UVR (2 kJ/m(2)) three times weekly from a bank of six Kodacel-filtered FS40 sunlamps (∼ 60% UVB and 40% UVA). Carcinoma incidence in mice treated with vehicle, 100, 200 or 500 nmol PL, at 44 weeks post-UVR, were 86, 80 (P = 0.67), 53 (P = 0.12) and 7% (P = 0.0075), respectively. Both vehicle and PL-treated mice gained weight and did not exhibit any signs of toxicity during the entire period of the experiment. Molecular mechanisms associated with inhibition of UVR-induced development of SCC involved induction of apoptosis and inhibition of cell proliferation. Specific findings are that PL treatment (i) inhibited UVR-induced DNA binding of activating protein-1, nuclear factor-kappaB, Stat3 transcription factors and Stat3-regulated molecules (cdc25A and Survivin); (ii) inhibited protein levels of pERK1/2, PI3K85, pAKTSer473, Bcl(2), BclxL, proliferating cell nuclear antigen and cell cycle inhibitory proteins p27 and p21 and (iii) increased UVR-induced Fas-associated death domain expression, poly (ADP-ribose) polymerase protein cleavage and Bax/Bcl(2) ratio. Taken together, our findings suggest that PL may be a novel agent for the prevention of skin cancer. Topics: Animals; Antineoplastic Agents, Phytogenic; Carcinoma, Squamous Cell; Cell Survival; DNA; Female; Mice; Naphthoquinones; Neoplasms, Radiation-Induced; NF-kappa B; Skin Neoplasms; STAT3 Transcription Factor; Transcription Factor AP-1; Ultraviolet Rays | 2012 |
YM155 reverses cisplatin resistance in head and neck cancer by decreasing cytoplasmic survivin levels.
Cisplatin is one of the commonly used chemotherapeutic drugs for the treatment of head and neck squamous cell carcinoma (HNSCC). However, acquisition of cisplatin resistance is common in patients with HNSCC, and it often leads to local and distant failure. In this study, we showed that survivin expression is significantly upregulated in HNSCC primary tumors and cell lines. In addition, survivin levels were significantly higher in human papilloma virus-negative patients that normally respond poorly to cisplatin treatment. Survivin expression was further increased in cisplatin-resistant cells (CAL27-CisR) as compared with its parent cells (CAL27). Therefore, we hypothesized that targeting of survivin in HNSCC could reverse the resistant phenotype in tumor cells, thereby enhancing the therapeutic efficacy of cisplatin. We used both in vitro and in vivo models to test the efficacy of YM155, a small molecule survivin inhibitor, either as a single agent or in combination with cisplatin. YM155 significantly decreased survivin levels and cell proliferation in a dose-dependent manner. In addition, YM155 pretreatment significantly reversed cisplatin resistance in cancer cells. Interestingly, YM155 treatment altered the dynamic localization of survivin in cells by inducing a rapid reduction in cytoplasmic survivin, which plays a critical role in its antiapoptotic function. In a severe combined immunodeficient mouse xenograft model, YM155 significantly enhanced the antitumor and antiangiogenic effects of cisplatin, with no added systemic toxicity. Taken together, our results suggest a potentially novel strategy to use YM155 to overcome the resistance in tumor cells, thereby enhancing the effectiveness of the chemotherapy in HNSCC. Topics: Adult; Aged; Animals; Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Proliferation; Cisplatin; Cytoplasm; Drug Synergism; Female; Head and Neck Neoplasms; Human papillomavirus 16; Humans; Imidazoles; Inhibitor of Apoptosis Proteins; Inhibitory Concentration 50; Male; Mice; Mice, SCID; Middle Aged; Naphthoquinones; Neovascularization, Pathologic; Papillomavirus Infections; Statistics, Nonparametric; Survivin; Tissue Array Analysis; Tumor Burden; Up-Regulation; Xenograft Model Antitumor Assays | 2012 |
[Role of NF-kappaB pathway in shikonin induced apoptosis in oral squamous cell carcinoma Tca-8113 cells].
To investigate the role of NF-kappaB signal transduction pathway in apoptosis induced by shikonin in human tongue squamous cell carcinoma Tca-8113 cell line.. Expression of IkappaBa, phosphatase-IkappaBa, bcl-2 and Bax proteins were detected by Western blot, NF-kappaB DNA-binding activity was detected by electrophoretic mobility shift analysis (EMSA), and activities of caspase 3, caspase 8 and caspase 9 were analyzed by enzyme linked immunosorbent assay(ELISA). The data was analyzed by one-way ANOVA test and t test using SPSS12.0 software package.. The expression of phosphatase-IkappaBa protein and the nuclear NF-kappaB DNA-binding activity was significantly decreased in shikonin treated cells by Western and EMSA. Bcl-2 protein expression was also decreased in the process. The activity of all the three proteases was elevated and pancaspase inhibitor Z-Asp-CH2-DCB could protect Tca8113 cells from shikonin-induced apoptosis(P=0.02).. Anti-tumor effects of shikonin in Tca-8113 cells act at least partially through the inactivation of NF-kappaB pathway and subsequent activation of protease caspase family. Pharmacologic inhibition of the NF-kappaB activity by shikonin might be a powerful treatment option for OSCC. Topics: Apoptosis; Aspartic Acid; Blotting, Western; Carcinoma, Squamous Cell; Cell Line, Tumor; Humans; Mouth Neoplasms; Naphthoquinones; NF-kappa B; Signal Transduction | 2010 |
Naphtho[1,2-b]furan-4,5-dione induces apoptosis of oral squamous cell carcinoma: involvement of EGF receptor/PI3K/Akt signaling pathway.
Naphtho[1,2-b]furan-4,5-dione (NFD), prepared from 2-hydroxy-1,4-naphthoquinone and chloroacetaldehyde in an efficient one-pot reaction, exerts an anti-tumor effect. This study was performed to elucidate whether the epidermal growth factor (EGF) receptor and phosphatidylinositol-3-kinase (PI3K) signaling pathways are involved in NFD-induced apoptosis of oral squamous cell carcinoma (OSCC). Immunoblot showed that NFD suppressed the phosphorylation of EGF receptor and activation of PI3K/Akt, downstream molecules of EGF receptor signaling pathway, in Ca9-22 cells. The levels of downstream targets of Akt, including phospho-glycogen synthase kinase-3beta (p-GSK-3beta), GSK-3beta, forkhead transcription factor (FKHR), and cyclin D1, were also reduced after NFD treatment. Moreover, inactivation of nuclear factor-kappaB (NF kappaB), modulation of I kappa K beta and I kappaB alpha, up-regulation of Bad, and down-regulation of anti-apoptotic proteins including phospho-Bad, Bcl-X(L), myeloid cell leukemia-1(Mcl-1), and XIAP were found in NFD-treated cells. In addition, NFD treatment disrupted mitochondrial membrane potential (Delta Psi m), resulted in release of cytochrome c, and activation of both caspases-9 and caspase-3. Taken together, these results indicate that NFD induces apoptosis in Ca9-22 cells via inactivation of the EGF receptor-mediated survival pathway. Topics: Apoptosis; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Proliferation; Cytochromes c; Enzyme Activation; ErbB Receptors; Humans; Inhibitor of Apoptosis Proteins; Membrane Potential, Mitochondrial; Mitochondria; Mouth Neoplasms; Naphthoquinones; NF-kappa B; Phosphatidylinositol 3-Kinases; Phosphorylation; Proto-Oncogene Proteins c-akt; Signal Transduction | 2010 |
The rotamase Pin1 is up-regulated, hypophosphorylated and required for cell cycle progression in head and neck squamous cell carcinomas.
The peptidyl-prolyl cis/trans isomerase Pin1 has been implicated in malignant transformation in multiple studies, however, little is known about its potential impact in head and neck cancer. This study evaluates the role of Pin1 in head and neck squamous cell carcinomas (HNSCCs). Pin1 expression and level of phosphorylation was evaluated by Western blot analysis and 2D-gel-electrophoresis. Pin1 was inhibited with juglone (5-hydroxy-1,4-naphthalenedione) or Pin1 specific siRNA and its influence on cell cycle checkpoint distribution was assessed by FACS analysis. Pin1 overexpression was found in HNSCC tissues and cell lines. 2D-gel-electrophoresis data pointed to Pin1 being hypophosphorylated in HNSCC cells which is consistent with overactivation of this rotamase. Inhibition of HNSCC cells with juglone or Pin1 siRNA induced the cell cycle inhibitor p21(WAF1/Cip1) with a concomitant reduction of cells in G2/M and an increased fraction of cells with fragmented DNA. Cell death did not correlate with significant levels of apoptosis in Pin1 depleted HNSCC cells. In summary, the data shows that Pin1 is overexpressed and hypophosphorylated in HNSCC, and that inhibition of Pin1 blocks cell cycle progression and triggers tumor cell death. Pin1 therefore could represent a new target for the development of improved HNSCC targeting drugs. Topics: Adult; Aged; Aged, 80 and over; Alkaline Phosphatase; Apoptosis; Blotting, Western; Carcinoma, Squamous Cell; Case-Control Studies; Cell Cycle; Cell Proliferation; Cyclin-Dependent Kinase Inhibitor p21; Electrophoresis, Gel, Two-Dimensional; Enzyme Inhibitors; Female; Head and Neck Neoplasms; Humans; Male; Middle Aged; Naphthoquinones; Neoplasm Proteins; NIMA-Interacting Peptidylprolyl Isomerase; Peptidylprolyl Isomerase; Phosphorylation; RNA, Small Interfering; Up-Regulation | 2009 |
Growth inhibition and induction of apoptosis in human oral squamous cell carcinoma Tca-8113 cell lines by Shikonin was partly through the inactivation of NF-kappaB pathway.
Shikonin, a naphthoquinone pigment isolated from the Chinese herbal therapeutic, Zicao, has been shown to exhibit antioxidant and anticancer effects. In this study, its ability to induce apoptosis in cultured Tca-8113 oral cancer cells was studied. Treatment of the Tca-8113 cells with a variety of concentrations of Shikonin (10-40 microm) resulted in dose- and time-dependent sequences of events marked by apoptosis, as shown by the loss of cell viability, chromatin condensation, internucleosomal DNA fragmentation and sub-G1 phase accumulation. Furthermore, apoptosis in the Tca-8113 cells was accompanied by the activation of protease caspase-8, -9, -3 and low expression of Bcl-2 protein. Interestingly, inactivation of the NF-kappaB pathway was found in shikonin-induced apoptosis in Tca-8113 cells. These results raise the possibility that the anti-tumor effects of Shikonin in Tca-8113 cells are at least partly through the inactivation of the NF-kappaB pathway and subsequent activation of protease caspase family. Pharmacological inhibition of the NF-kappaB activity by Shikonin might be a powerful treatment option for OSCC in which activation of NF-kappaB plays a critical role in tumor growth and progression. Topics: Anti-Inflammatory Agents, Non-Steroidal; Antibodies, Monoclonal; Antineoplastic Agents, Phytogenic; Apoptosis; Carcinoma, Squamous Cell; Caspases; Cell Cycle; Cell Line, Tumor; Cell Proliferation; DNA; DNA Fragmentation; Dose-Response Relationship, Drug; Drugs, Chinese Herbal; Gene Expression; Humans; Naphthoquinones; NF-kappa B; Proto-Oncogene Proteins c-bcl-2; Time Factors | 2008 |
2D-autocorrelation descriptors for predicting cytotoxicity of naphthoquinone ester derivatives against oral human epidermoid carcinoma.
A QSAR study was developed, employing 2D-autocorrelation descriptors and a set of 37 naphthoquinone ester derivatives, in order to model the cytotoxicity of these compounds against oral human epidermoid carcinoma (KB). A comparison with other approaches such as the BCUT, Galvez topological charge indexes, Randić molecular profile, Geometrical, and RDF descriptors was carried out. Mathematical models were obtained by means of the multiple regression analysis (MRA) and the variables were selected using genetic algorithm. Based on the statistical results the 2D-autocorrelation descriptors were considered the best and were able to describe more than 84.2% of the variance in the experimental activity once we controlled for outliers. Topics: Algorithms; Antineoplastic Agents; Carcinoma, Squamous Cell; Cell Line, Tumor; Esters; Humans; KB Cells; Linear Models; Models, Molecular; Models, Statistical; Naphthoquinones; Quantitative Structure-Activity Relationship; Reproducibility of Results; Skin Neoplasms | 2007 |
Role of lysosomal cathepsins in naphthazarin- and Fas-induced apoptosis in oral squamous cell carcinoma cells.
Intracellular cysteine cathepsins are pro-apoptotic factors involved in activation of caspases in two oral squamous cell carcinoma (SCC) cell lines.. To study the possible involvement of lysosomal cathepsins in oral SCC cell apoptosis.. Apoptosis was induced in the two human oral SCC cell lines UT-SCC-20A and UT-SCC-24A using naphthazarin or anti-Fas antibodies, and was studied by analysis of caspase activity and nuclear morphology. Involvement of lysosomal cathepsins was investigated using the cysteine cathepsin inhibitor z-FA-FMK and the cathepsin D inhibitor pepstatin A. The amounts of cellular and soluble Fas death receptor were determined by ELISA.. Release of cathepsins from the lysosomes to the cytosol was observed early in apoptosis. Cysteine cathepsins were found to be involved in activation of caspases in response to treatment with naphthazarin or anti-Fas antibodies, but inhibition of cysteine cathepsin activity was not sufficient to prevent cell death. Moreover, inhibition of cysteine cathepsin activity resulted in increased expression of the Fas death receptor, suggesting involvement of extracellular cysteine cathepsins in death receptor shedding. Topics: Antineoplastic Agents; Apoptosis; Blotting, Western; Carcinoma, Squamous Cell; Caspases; Cathepsins; Cell Line, Tumor; Cysteine Proteinase Inhibitors; Cytosol; Dipeptides; Enzyme-Linked Immunosorbent Assay; fas Receptor; Fluorescent Antibody Technique; Humans; Intracellular Membranes; Ketones; Lysosomes; Mouth Neoplasms; Multivariate Analysis; Naphthoquinones; Signal Transduction | 2006 |
Amplified telomerase analysis by using rotating magnetic particles: the rapid and sensitive detection of cancer cells.
A highly sensitive telomerase detection method that involves amplified telomerase analysis and the use of rotating magnetic particles has been developed. Magnetic particles, functionalized with a primer (1) that is recognized by telomerase, are mixed with a nucleotide mixture that includes biotinylated-dUTP, and telomerase-induced elongation of the primers proceeds with simultaneous biotin incorporation. Avidin-Horseradish peroxidase conjugate, coupled to biotin labels, yields the biocatalytic functional particles. Mixing the resulting particles with naphthoquinone-modified magnetic particles enables the optoelectronic detection of telomerase. Attraction of the magnetic particles to an electrode, followed by rotation of the particles, causes the electrocatalytic reduction of O(2) to H(2)O(2) and HRP-catalyzed oxidation of luminol (3); this results in chemilumunescence. The intensity of the emitted light depends on the telomerase content of the sample and the rotation speed of the particles. A minimum number of 10 cancer cells could be detected. Topics: Adenocarcinoma; Biosensing Techniques; Biotinylation; Carcinoma, Squamous Cell; Cells, Cultured; DNA; HeLa Cells; Horseradish Peroxidase; Humans; Hydrogen Peroxide; Kidney; Luminescent Measurements; Luminol; Lung Neoplasms; Magnetics; Naphthoquinones; Sensitivity and Specificity; Telomerase | 2004 |
Shikonin modulates cell proliferation by inhibiting epidermal growth factor receptor signaling in human epidermoid carcinoma cells.
Shikonin isolated from the roots of the Chinese herb Lithospermum erythrorhizon has been associated with anti-inflammatory properties. We evaluated shikonin's chemotherapeutic potential and investigated its possible mechanism of action in a human cutaneous neoplasm in tissue culture. Shikonin preferentially inhibits the growth of human epidermoid carcinoma cells concentration- and time-dependently compared to SV-40 transfected keratinocytes, demonstrating its anti-proliferative effects against this cancer cell line. Additionally, shikonin decreased phosphorylated levels of EGFR, ERK1/2 and protein tyrosine kinases, while increasing phosphorylated JNK1/2 levels. Overall, shikonin treatment was associated with increased intracellular levels of phosphorylated apoptosis-related proteins, and decreased levels of proteins associated with proliferation in human epidermoid carcinoma cells. Topics: Carcinoma, Squamous Cell; Cell Division; Enzyme Inhibitors; ErbB Receptors; Humans; MAP Kinase Signaling System; Naphthoquinones; Phosphorylation; Protein-Tyrosine Kinases; Signal Transduction; Tumor Cells, Cultured | 2003 |
[Clinical trial on the effects of shikonin mixture on later stage lung cancer].
The shikonin mixture was used for 19 cases of later-stage lung cancer who were not the candidates for operation, radiotherapy and chemotherapy. The clinical observation showed that shikonin mixture could inhibit the growth of lung cancer and improve the immune function of the body. The tumors were reduced over 25% in diameter. The effective rate was 63.3%, remission rate 36.9%, survival rate of one year 47.3%. The intermedium survival period was about 10 months, including adenocarcinoma 10 months, squamous carcinoma 12 months. After treatment the life quality of patients were greatly improved. The patients got better appetite and their body weights were increased. They could manage themselves in daily life. The Karnofsky scores were enhanced by 20. The authors also observed that shikonin mixture could relieve such symptoms as cough, bloody sputum and chest pain caused by lung cancer. The levels of cells and interleukin-2 were increased (P less than 0.001). It had no harmful effects on peripheral blood picture, heart, kidney and liver. Shikonin mixture is safe and effective for later-stage cancer. Topics: Adenocarcinoma; Adult; Antineoplastic Agents, Phytogenic; Carcinoma, Bronchogenic; Carcinoma, Squamous Cell; Female; Ginsenosides; Humans; Interleukin-2; Killer Cells, Natural; Lung Neoplasms; Male; Middle Aged; Naphthoquinones; Saponins | 1991 |
Potentiation of halogenated pyrimidine radiosensitizers in human carcinoma cells by beta-lapachone (3,4-dihydro-2,2-dimethyl-2H-naphtho[1,2-b]pyran- 5,6-dione), a novel DNA repair inhibitor.
3,4-Dihydro-2,2-dimethyl-2H-naptho[1,2,-b]pyran-5,6-dione (beta-lapachone) is a novel DNA repair inhibitor. It was tested for synergistic X-ray-induced lethality in combination with several halogenated pyrimidine radiosensitizers. Logarithmic-phase growing human epidermoid laryngeal carcinoma (HEp-2) cells were allowed to incorporate pyrimidine analogues for 48 h (approximately two cell doublings) and then were X-irradiated and subjected to various posttreatments. beta-Lapachone synergistically increased the dose enhancement ratios (DERs) of all analogues screened, with the exception of the 2'-chloro derivative of 5-bromodeoxyuridine. For example, following 5-bromodeoxycytidine sensitization an X-ray DER value of 1.87 +/- 0.04 at 1% survival was increased to 3.51 +/- 0.42 due to a 4-h post-X-irradiation exposure to 4 microM beta-lapachone. Do and Dq values for halogenated pyrimidine-sensitized human epidermoid laryngeal carcinoma cells were decreased 1.4- to 5.4-fold and 1.4- to 4.0-fold, respectively. beta-Lapachone had little effect upon the cytotoxicities of unirradiated human epidermoid laryngeal carcinoma cells whether or not they were previously exposed to any of the halogenated pyrimidine radiosensitizers. beta-Lapachone treatment following X-irradiation of cells that had not incorporated a pyrimidine analogue exhibited DER values of 1.38 +/- 0.05 and 1.40 +/- 0.01 at 10 and 1% survival levels, respectively. beta-Lapachone enhanced the radiosensitization of deoxycytidine analogues to a greater extent than the structurally related deoxyuridine analogues. Greater DERs and lower Do and Dq values were found for deoxycytidine than for deoxyuridine analogue radiosensitizers following beta-lapachone treatment. This agent may improve presently used radiation therapies and enhance proposed strategies which utilize deoxycytidine analogue radiosensitization together with protection of normal tissues by tetrahydrouridine to achieve tumor-selective radiotherapy. Topics: Bromodeoxycytidine; Bromodeoxyuridine; Carcinoma, Squamous Cell; Cell Line; Cells, Cultured; DNA Repair; Drug Synergism; Humans; Laryngeal Neoplasms; Naphthoquinones; Radiation-Sensitizing Agents | 1987 |
Mechanism of action of granaticin: inhibition of ribosomal RNA maturation and cell cycle specificity.
Granaticin, an antibiotic produced by Streptomyces species was found to be cytotoxic (ED50 3.2 microgram/ml) against human oral epidermoid carcinoma (KB) cells. AT ED50 concentrations RNA synthesis was inhibited to the greatest extent. Prelabeling of RNA in KB cells, followed by addition of granaticin (2.13 microgram/ml) showed that ribosomal RNA maturation was inhibited. The inhibition of the formation of functional ribosomal RNA was determined by sucrose gradient centrifugation and showed that the accumulation of 45S preribosomal RNA was dependent on granaticin concentration and on the time granaticin was in contact with the KB cells. The effect of granaticin (6.3 microgram/ml) on KB cells in the different cell cycle phases showed preferential inhibition (93%) of cell survival in the G2 phase. However, RNA synthesis was only 20% inhibited by granaticin in KB cells in the G2 phase. From these results, it was concluded that ribosomal RNA maturation was not the only site of action of granaticin toxicity. Topics: Antibiotics, Antineoplastic; Carcinoma, Squamous Cell; Cell Cycle; Cell Survival; Cells, Cultured; Humans; Naphthoquinones; Neoplasms, Experimental; RNA, Neoplasm; RNA, Ribosomal; Thymidine; Uridine | 1982 |
Inhibition of synthesis of pyrimidine nucleotides by 2-hydroxy-3-(3,3-dichloroallyl)-1,4-naphthoquinone.
Topics: Animals; Carcinoma, Squamous Cell; Cells, Cultured; Dihydroorotate Oxidase; Humans; In Vitro Techniques; Leukemia L1210; Mice; Mice, Inbred Strains; Mitochondria, Liver; Naphthoquinones; Pyrimidine Nucleotides | 1979 |