RESUMO
The population-based cohort study used the Korean National Health Insurance claims database to evaluate the effect of anti-diabetic drugs on osteoporosis. The use of DPP-IV inhibitors does not increase the risk of osteoporosis compared with the use of sulfonylureas in patients with type 2 diabetes mellitus, while a weak association was found between thiazolidinediones and increased risk of osteoporosis. PURPOSE: The current study aimed to evaluate the effect of dipeptidyl peptidase IV inhibitors (DPP-IVi), thiazolidinedione (TZD), and sulfonylurea (SU) on osteoporosis in patients with type 2 diabetes. METHODS: A population-based cohort study was conducted in the Republic of Korea using the Korean National Health Insurance claims database. Data from 2012 to 2017 for patients of 50-99 years of age who were prescribed DPP-IVi, TZD, or SU during 2013-2015 were extracted from the database. Based on pre-defined criteria, a total of 381,404 patients were analyzed after inverse probability of treatment weighting. The association between the study drugs and osteoporosis was estimated using Cox proportional hazards models. Data of 220,166 patients who were prescribed DPP-IVi, 18,630 who were prescribed TZD, and 142,608 patients who were prescribed SU were set. RESULTS: In the multivariate-adjusted analysis, the hazard ratio (HR) of osteoporosis in the DPP-IVi group was not significantly different from that of the SU group (HR: 0.97; 95% confidence interval (CI) 0.94-1.00), whereas the HR of osteoporosis in the TZD group was higher (HR: 1.13; 95% CI 1.06-1.20). In the subgroup analysis, the HRs of osteoporosis were higher with pioglitazone (HR: 1.14; 95% CI 1.06-1.23) in the TZD group and with glibenclamides (HR: 1.39; 95% CI 1.09-1.77) in the SU group, whereas drugs with lower HR in the DPP-IVi group were saxagliptin (HR: 0.93; 95% CI 0.87-0.99) and sitagliptin (HR: 0.93; 95% CI 0.89-0.97). CONCLUSION: DPP-IV inhibitors do not increase the risk of osteoporosis compared with sulfonylureas in patients with type 2 diabetes mellitus, while a weak association was found between thiazolidinediones and increased risk of osteoporosis.
Assuntos
Diabetes Mellitus Tipo 2 , Inibidores da Dipeptidil Peptidase IV , Osteoporose , Tiazolidinedionas , Estudos de Coortes , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/epidemiologia , Inibidores da Dipeptidil Peptidase IV/efeitos adversos , Humanos , Osteoporose/induzido quimicamente , Osteoporose/tratamento farmacológico , Osteoporose/epidemiologia , Tiazolidinedionas/efeitos adversosRESUMO
BACKGROUND: To evaluate the effects of elective nodal irradiation (ENI) in clinical stage II-III breast cancer patients with pathologically negative lymph nodes (LNs) (ypN0) after neoadjuvant chemotherapy (NAC) followed by breast-conserving surgery (BCS) and radiotherapy (RT). METHODS: We retrospectively analysed 260 patients with ypN0 who received NAC followed by BCS and RT. Elective nodal irradiation was delivered to 136 (52.3%) patients. The effects of ENI on survival outcomes were evaluated. RESULTS: After a median follow-up period of 66.2 months (range, 15.6-127.4 months), 26 patients (10.0%) developed disease recurrence. The 5-year locoregional recurrence-free survival and disease-free survival (DFS) for all patients were 95.5% and 90.5%, respectively. Pathologic T classification (0-is vs 1 vs 2-4) and the number of LNs sampled (<13 vs ≥13) were associated with DFS (P=0.0086 and 0.0012, respectively). There was no significant difference in survival outcomes according to ENI. Elective nodal irradiation also did not affect survival outcomes in any of the subgroups according to pathologic T classification or the number of LNs sampled. CONCLUSIONS: ENI may be omitted in patients with ypN0 breast cancer after NAC and BCS. But until the results of the randomised trials are available, patients should be put on these trials.
Assuntos
Neoplasias da Mama/terapia , Linfonodos/patologia , Irradiação Linfática/métodos , Adulto , Idoso , Neoplasias da Mama/patologia , Intervalo Livre de Doença , Feminino , Humanos , Linfonodos/cirurgia , Metástase Linfática , Pessoa de Meia-Idade , Terapia Neoadjuvante , Estadiamento de Neoplasias , Estudos Retrospectivos , Adulto JovemRESUMO
The new allele B*40:186 shows a one nucleotide substitution compared with B*40:01:02 at codon 56 (GGG â AGG) resulting in coding change, Gly to Arg.
Assuntos
Alelos , Antígeno HLA-B40/genética , Nucleotídeos/genética , Substituição de Aminoácidos , Povo Asiático , Sequência de Bases , Códon , Éxons , Loci Gênicos , Antígeno HLA-B40/imunologia , Teste de Histocompatibilidade , Humanos , Íntrons , Dados de Sequência Molecular , Isoformas de Proteínas/genética , Isoformas de Proteínas/imunologia , Análise de Sequência de DNA , Homologia de Sequência do Ácido NucleicoRESUMO
BACKGROUND: Sertraline is a naphthalenamine derivative which has the effect of selective serotonin reuptake inhibition. It has been used for major depression, and obsessive compulsive disorder. This study was performed to evaluate the pharmacokinetic (PK) characteristics after the administration of low dose sertraline for the purpose of exploring an application of microdosing methods in PK studies. METHODS: An open-label, three-period, single-sequence, dose-escalation study was performed in 6 healthy Korean male volunteers. Subjects were administered a single dose of 5 mg, 25 mg and 50 mg sertraline orally in each period, with 1 week washouts between periods. Blood samples were obtained up to 96 h after drug administration. Plasma concentrations were determined using high performance liquid chromatography-tandem mass spectrometry. PK parameters of sertraline were analyzed using non-compartmental methods. RESULTS: A total of 6 subjects completed the study. After the administration of sertraline at 5 mg, 25 mg and 50 mg, the median tmax were 6.0, 6.0 and 4.0 h and the mean (SD) elimination half-lives were 31.9 (6.5), 27.2 (6.7) and 28.0 (6.6) h, respectively. The AUC and Cmax increased dose-dependently. The dose-normalized mean (SD) AUC and Cmax were different in each dosing group (p < 0.01) with 2.0 (0.8), 5.3 (1.2) and 6.0 (1.9) mg × hr/l/mg in the 5 mg, 25 mg and 50 mg groups for dose-normalized AUC, and 0.07 (0.01), 0.18 (0.05) and 0.21 (0.08) mg/l/mg in the 5 mg, 25 mg and 50 mg groups for dose-normalized Cmax, respectively, which indicates a lack of dose proportionality. CONCLUSION: A lack of dose proportional properties was shown in the 5 mg dose relative to the 25 mg and 50 mg doses of sertraline. This shows that the PK parameters for low-dose sertraline could be different from those in clinical concentrations.
Assuntos
Inibidores Seletivos de Recaptação de Serotonina/farmacocinética , Sertralina/farmacocinética , Adulto , Área Sob a Curva , Relação Dose-Resposta a Droga , Humanos , Coreia (Geográfico) , Masculino , Pessoa de Meia-Idade , Sertralina/efeitos adversos , Adulto JovemRESUMO
BACKGROUND: Although trastuzumab therapy improves survival in patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer, 40% of patients develop brain metastasis (BM) even when extracranial disease is under control. We studied whether trastuzumab therapy beyond or after BM was beneficial to patients with BM. PATIENTS AND METHODS: The effect of trastuzumab on survival after BM was analyzed in 78 HER2-positive breast cancer patients. Patients were grouped according to trastuzumab therapy; no treatment and treatment before and after BM were diagnosed. RESULTS: Overall survival after the diagnosis of BM as well as time to progression (TTP) of intracranial tumors was prolonged in patients who received trastuzumab after BM was diagnosed. Conversely, BM occurred much later in patients who received trastuzumab before BM. In the multivariate Cox regression model, age at BM <50 years, disease-free interval >or=24 months, TTP of intracranial tumor >or=4.8 months, and trastuzumab treatment after BM were significantly associated with longer survival after the onset of BM. CONCLUSIONS: Trastuzumab therapy after the onset of BM in HER2-positive breast cancer patients is associated with a significant survival benefit after BM diagnosis compared with patients who never received or completed trastuzumab before the BM diagnosis.
Assuntos
Anticorpos Monoclonais/uso terapêutico , Antineoplásicos/uso terapêutico , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/secundário , Neoplasias da Mama/tratamento farmacológico , Carcinoma/tratamento farmacológico , Receptor ErbB-2/metabolismo , Adulto , Idoso , Algoritmos , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais Humanizados , Antineoplásicos/farmacologia , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/mortalidade , Neoplasias da Mama/metabolismo , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Carcinoma/metabolismo , Carcinoma/mortalidade , Carcinoma/patologia , Progressão da Doença , Feminino , Humanos , Pessoa de Meia-Idade , Receptor ErbB-2/genética , Estudos Retrospectivos , Análise de Sobrevida , Trastuzumab , Resultado do TratamentoRESUMO
Oral mucosa provides the first line of defense against a diverse array of environmental and microbial irritants by forming the barrier of epithelial cells interconnected by multiprotein tight junctions (TJ), adherens junctions, desmosomes, and gap junction complexes. Grainyhead-like 2 (GRHL2), an epithelial-specific transcription factor, may play a role in the formation of the mucosal epithelial barrier, as it regulates the expression of the junction proteins. The current study investigated the role of GRHL2 in the Porphyromonas gingivalis (Pg)-induced impairment of epithelial barrier functions. Exposure of human oral keratinocytes (HOK-16B and OKF6 cells) to Pg or Pg-derived lipopolysaccharides (Pg LPSs) led to rapid loss of endogenous GRHL2 and the junction proteins (e.g., zonula occludens, E-cadherin, claudins, and occludin). GRHL2 directly regulated the expression levels of the junction proteins and the epithelial permeability for small molecules (e.g., dextrans and Pg bacteria). To explore the functional role of GRHL2 in oral mucosal barrier, we used a Grhl2 conditional knockout (KO) mouse model, which allows for epithelial tissue-specific Grhl2 KO in an inducible manner. Grhl2 KO impaired the expression of the junction proteins at the junctional epithelium and increased the alveolar bone loss in the ligature-induced periodontitis model. Fluorescence in situ hybridization revealed increased epithelial penetration of oral bacteria in Grhl2 KO mice compared with the wild-type mice. Also, blood loadings of oral bacteria (e.g., Bacteroides, Bacillus, Firmicutes, ß-proteobacteria, and Spirochetes) were significantly elevated in Grhl2 KO mice compared to the wild-type littermates. These data indicate that Pg bacteria may enhance paracellular penetration through oral mucosa in part by targeting the expression of GRHL2 in the oral epithelial cells, which then impairs the epithelial barrier by inhibition of junction protein expression, resulting in increased alveolar tissue destruction and systemic bacteremia.
Assuntos
Proteínas de Ligação a DNA/metabolismo , Mucosa Bucal/microbiologia , Porphyromonas gingivalis/patogenicidade , Junções Íntimas , Fatores de Transcrição/metabolismo , Animais , Células Cultivadas , Células Epiteliais , Humanos , Hibridização in Situ Fluorescente , Camundongos , Camundongos Knockout , Fatores de Transcrição/genéticaRESUMO
High-risk human papillomavirus (HPV) is a major risk factor for oral and pharyngeal cancers (OPCs), yet the detailed mechanisms by which HPV promotes OPCs are not understood. Forkhead box M1B (FoxM1B) is an oncogene essential for cell cycle progression and tumorigenesis, and it is aberrantly overexpressed in many tumors. We previously showed that FoxM1B was the putative target of an epithelial-specific transcription factor, Grainyhead-like 2 (GRHL2). In the current study, we demonstrate that HPV type 16 (HPV-16) E6 induces FoxM1B in human oral keratinocytes (HOKs) and tonsillar epithelial cells (TECs) in part through GRHL2. FoxM1B was barely detectable in cultured normal human oral keratinocytes (NHOKs) and progressively increased in immortalized HOKs harboring HPV-16 genome (HOK-16B) and tumorigenic HOK-16B/BaP-T cells. Retroviral expression of HPV-16 E6 and/or E7 in NHOKs, TECs, and hypopharyngeal carcinoma cells (FaDu) revealed induction of FoxM1B and GRHL2 by the E6 protein but not E7. Both GRHL2 and FoxM1B were strongly induced in the epidermis of HPV-16 E6 transgenic mice and HPV+ oral squamous cell carcinomas. Ectopic expression of FoxM1B led to acquisition of transformed phenotype in HOK-16B cells. Loss of FoxM1B by lentiviral short hairpin RNA vector or chemical inhibitor led to elimination of tumorigenic characteristics of HOK-16B/BaP-T cells. Luciferase reporter assay revealed that GRHL2 directly bound and regulated the FoxM1B gene promoter activity. Using epithelial-specific Grhl2 conditional knockout mice, we exposed wild-type (WT) and Grhl2 KO mice to 4-nitroquinolin 1-oxide (4-NQO), which led to induction of FoxM1B in the tongue tissues and rampant oral tumor development in the WT mice. However, 4-NQO exposure failed to induce tongue tumors or induction of FoxM1B expression in Grhl2 KO mice. Collectively, these results indicate that HPV-16 induces FoxM1B in part through GRHL2 transcriptional activity and that elevated FoxM1B level is required for oropharyngeal cancer development.
Assuntos
Proteínas de Ligação a DNA/fisiologia , Células Epiteliais/metabolismo , Proteína Forkhead Box M1/metabolismo , Queratinócitos/metabolismo , Proteínas Oncogênicas Virais/fisiologia , Neoplasias Orofaríngeas/virologia , Proteínas Repressoras/fisiologia , Fatores de Transcrição/fisiologia , Animais , Western Blotting , Carcinogênese/metabolismo , Linhagem Celular Tumoral , Modelos Animais de Doenças , Técnicas de Inativação de Genes , Humanos , Imuno-Histoquímica , Tonsila Palatina/citologia , Infecções por Papillomavirus/virologia , Reação em Cadeia da Polimerase , Células Tumorais CultivadasRESUMO
Direct pulp capping involves the placement of dental materials directly onto vital pulp tissues after deep caries removal to stimulate the regeneration of reparative dentin. This physical barrier will serve as a "biological seal" between these materials and the pulp tissue. Although numerous direct pulp capping materials are available, the use of small bioactive compounds that can potently stimulate and expedite reparative dentin formation is still underexplored. Here, the authors compared and evaluated the pro-osteogenic and pro-odontogenic effects of 4 small bioactive compounds- phenamil (Phen), purmorphamine (Pur), genistein (Gen), and metformin (Met). The authors found that these compounds at noncytotoxic concentrations induced differentiation and mineralization of preosteoblastic MC3T3-E1 cells and preodontoblastic dental pulp stem cells (DPSCs) in a dose-dependent manner. Among them, Phen consistently and potently induced differentiation and mineralization in vitro. A single treatment with Phen was sufficient to enhance the mineralization potential of DPSCs in vitro. More importantly, Phen-treated DPSCs showed enhanced odontogenic differentiation and mineralization in vivo. Our study suggests that these small bioactive compounds merit further study for their potential clinical use as pulp capping materials.
Assuntos
Amilorida/análogos & derivados , Calcificação Fisiológica/efeitos dos fármacos , Genisteína/farmacologia , Metformina/farmacologia , Morfolinas/farmacologia , Odontogênese/efeitos dos fármacos , Purinas/farmacologia , Amilorida/farmacologia , Animais , Polpa Dentária/citologia , Polpa Dentária/crescimento & desenvolvimento , Relação Dose-Resposta a Droga , Camundongos , Camundongos Nus , Transplante de Células-Tronco/métodosRESUMO
14 C-labeled YH4808, a novel potassium-competitive acid blocker, was intravenously administered as a microtracer at 80 µg (11.8 kBq or 320 nCi) concomitantly with the nonradiolabeled oral drug at 200 mg to determine the absolute bioavailability and to assess the effect of pharmacogenomics on the oral absorption of YH4808. The absolute bioavailability was low and highly variable (mean, 10.1%; range, 2.3-19.3%), and M3 and M8, active metabolites of YH4808, were formed 22.6- and 38.5-fold higher after oral administration than intravenous administration, respectively. The product of the fraction of an oral YH4808 dose entering the gut wall and the fraction of YH4808 passing on to the portal circulation was larger in subjects carrying the variants of the CHST3, SLC15A1, and SULT1B1 genes. A combined LC+AMS is a useful tool to construct a rich and highly informative pharmacokinetic knowledge core in early clinical drug development at a reasonable cost.
Assuntos
Antiulcerosos/administração & dosagem , Desenho de Fármacos , Espectrometria de Massas/métodos , Farmacogenética , Bloqueadores dos Canais de Potássio/administração & dosagem , Administração Intravenosa , Administração Oral , Adulto , Antiulcerosos/farmacocinética , Disponibilidade Biológica , Radioisótopos de Carbono , Humanos , Masculino , Bloqueadores dos Canais de Potássio/farmacocinéticaRESUMO
To explore potential biomarkers for amoxicillin/clavulanate-induced liver injury (AC-DILI), we conducted a clinical trial in 32 healthy subjects based on multi-omics approaches. Every subject was administered amoxicillin/clavulanate for 14 days. The liver-specific microRNA-122 (miR-122) level increased prior to and correlated well with the observed alanine aminotransferase (ALT) level increase. This result indicates its potential as a sensitive early marker for AC-DILI. We also identified urinary metabolites, such as azelaic acid and 7-methylxanthine, with levels that significantly differed among the groups classified by ALT elevation level on day 8 after drug administration (P < 0.05). Lymphocyte proliferation in response to the drug was also observed. These findings demonstrate sequential changes in the process of AC-DILI, including metabolic changes, increased miR-122 level, increased liver enzyme activity, and enhanced lymphocyte proliferation after drug administration. In conclusion, this study provides potential biomarkers for AC-DILI based on currently known mechanisms using comprehensive multi-omics approaches.
Assuntos
Amoxicilina/efeitos adversos , Biomarcadores/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Ácido Clavulânico/efeitos adversos , Adulto , Alanina Transaminase/sangue , Amoxicilina/farmacocinética , Biomarcadores/sangue , Biomarcadores/urina , Proliferação de Células , Doença Hepática Induzida por Substâncias e Drogas/sangue , Doença Hepática Induzida por Substâncias e Drogas/urina , Ácido Clavulânico/farmacocinética , Demografia , Humanos , Linfócitos/metabolismo , Masculino , Metaboloma , MicroRNAs/sangue , Fatores de TempoRESUMO
Autosomal dominant disorders of skeletal and cranial development have been linked to fibroblast growth factor receptor (FGFR) 2 and FGFR3. Here we report two identical mutations in FGFR2 that cause craniosynostosis syndromes, Crouzon, Apert, and Pfeiffer in gastric carcinoma. A missense mutation (Ser267Pro) in exon IIIa and a splice site mutation (940-2A-->G) in exon IIIc were detected in gastric cancer patients. Interestingly, these heterozygous somatic mutations are identical to the germinal activating mutations in FGFR2 reported previously in craniosynostosis syndromes. In addition, the two novel mutations of FGFR3 in colorectal carcinomas were identified. All identified mutations occurred at highly conserved sequences, not only in the FGFR family of molecules, but also throughout evolution and clustered in the immunoglobulin-like loop-III domain, highlighting the functional importance of this domain. Our results indicate that FGFR2 and FGFR3, in addition to their potential role in skeletal dysplasias, play an important role in tumorigenesis.
Assuntos
Neoplasias Colorretais/genética , Mutação de Sentido Incorreto , Proteínas Tirosina Quinases , Receptores Proteína Tirosina Quinases/genética , Receptores de Fatores de Crescimento de Fibroblastos/genética , Neoplasias Gástricas/genética , Sequência de Aminoácidos , Animais , Sequência Conservada , Craniossinostoses/genética , Humanos , Camundongos , Dados de Sequência Molecular , Ratos , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos , Receptor Tipo 3 de Fator de Crescimento de FibroblastosRESUMO
We previously immortalized human oral keratinocytes by transfection with recombinant human papillomavirus type 16 (HPV-16) DNA and established two cell lines. These transfected cells were morphologically different from the normal counterpart, contained intact HPV-16 DNA in an integrated form, and expressed numerous viral genes. These cells contained lower levels of wild-type p53 protein and higher levels of c-myc mRNAs compared to normal cells. However, they proliferated only in keratinocyte growth medium containing a low level of calcium and were not tumorigenic in nude mice. A HPV-16-immortalized cell line was exposed to either 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone or N-methyl-N'-nitro-N-nitrosoguanidine. Four chemically transformed cell colonies were isolated. These cells proliferated well in Dulbecco's minimum essential medium containing a physiological level of calcium. They contained, similar to the immortalized counterpart, integrated HPV-16 sequences and lower levels of both wild-type p53 protein and DCC messages compared to normal cells. Among the chemically transformed cells, two colonies obtained from 4-(methyl-nitrosamino)-1-(3-pyridyl)-1-butanone exposure demonstrated an enhanced proliferation capacity in nude mice and transcribed a substantially higher amount of HPV-16 E6/E7, epidermal growth factor receptors, and c-myc genes compared with the immortalized counterpart. These experiments indicate that malignant transformation of oral keratinocytes can be caused by a sequential combined effect of "high risk" HPV and tobacco-related carcinogens.
Assuntos
Carcinógenos/toxicidade , Transformação Celular Neoplásica , Queratinócitos/citologia , Metilnitronitrosoguanidina/toxicidade , Neoplasias Bucais/etiologia , Nicotiana , Nitrosaminas/toxicidade , Papillomaviridae , Plantas Tóxicas , Sequência de Bases , Divisão Celular , Linhagem Celular Transformada , Células Cultivadas , Neoplasias do Colo/genética , Primers do DNA , Receptores ErbB/genética , Éxons , Genes myc , Genes p53 , Genes ras , Humanos , Queratinócitos/efeitos dos fármacos , Masculino , Dados de Sequência Molecular , Neoplasias Bucais/induzido quimicamente , Neoplasias Bucais/microbiologia , Mutagênese , Oligonucleotídeos Antissenso , Reação em Cadeia da Polimerase , Fator de Crescimento Transformador alfa/genéticaRESUMO
A nested reverse transcription-PCR analysis of FGFR3 from human colorectal carcinomas revealed novel mutant transcripts caused by aberrant splicing and activation of cryptic splice sequences. Two aberrantly spliced transcripts were detected with high frequency in 50% of 36 primary tumors and in 60% of 10 human colorectal cancer cell lines. Most transcripts used normal splice sites but skipped or included exons 8 and 9. Two mutant transcripts arose from cryptic splice donor sites in exon 7 that spliced to exon 10. The predicted translation products would exhibit frameshifts and a premature termination codon in exon 10. We propose that dysregulation of mRNA splicing frequently generates an aberrant FGFR3 transcript that may confer a selectable advantage on clones of cells in colorectal tumorigenesis.
Assuntos
Processamento Alternativo/genética , Neoplasias Colorretais/genética , Regulação Neoplásica da Expressão Gênica , Proteínas Tirosina Quinases , RNA Mensageiro/genética , Receptores de Fatores de Crescimento de Fibroblastos/genética , Sequência de Aminoácidos , Códon sem Sentido , Neoplasias Colorretais/metabolismo , Regulação para Baixo , Éxons/genética , Mutação da Fase de Leitura , Humanos , Dados de Sequência Molecular , Terminação Traducional da Cadeia Peptídica , RNA Mensageiro/metabolismo , Receptor Tipo 3 de Fator de Crescimento de Fibroblastos , Receptores de Fatores de Crescimento de Fibroblastos/biossíntese , Células Tumorais CultivadasRESUMO
The presence of a di-unsaturated highly branched isoprenoid (HBI) lipid biomarker (diene II) in Southern Ocean sediments has previously been proposed as a proxy measure of palaeo Antarctic sea ice. Here we show that a source of diene II is the sympagic diatom Berkeleya adeliensis Medlin. Furthermore, the propensity for B. adeliensis to flourish in platelet ice is reflected by an offshore downward gradient in diene II concentration in >100 surface sediments from Antarctic coastal and near-coastal environments. Since platelet ice formation is strongly associated with super-cooled freshwater inflow, we further hypothesize that sedimentary diene II provides a potentially sensitive proxy indicator of landfast sea ice influenced by meltwater discharge from nearby glaciers and ice shelves, and re-examination of some previous diene II downcore records supports this hypothesis. The term IPSO25-Ice Proxy for the Southern Ocean with 25 carbon atoms-is proposed as a proxy name for diene II.
RESUMO
HPV-immortalized human oral keratinocytes can convert to tumorigenic cells when exposed to N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), but normal human oral keratinocytes cannot transform with a similar exposure. The different responses of these cells could be due to different genetic stability of cells. In as much as genetic stability is determined by cell cycle control and of repair of damaged DNA, we studied the effect of MNNG exposure upon cell cycle progression, expression of p53, WAF1/CIP1 and gadd45, and the mutation frequency of a shuttle vector pS189 in normal human oral keratinocytes, in HPV-immortalized oral keratinocytes, and in an oral cancer cell line expressing mutant p53. Normal cells demonstrated transient cell cycle arrest after exposure to MNNG, but the other tested cells did not. While MNNG exposure significantly increased the levels of intranuclear wt p53 protein and the expression of WAF1/CIP1 and gadd45 genes in normal cells, it did not alter them in the immortalized and cancer cells. The mutation frequency of pS189 plasmid was significantly lower in normal cells than in the other tested cells. These data indicate that malignant conversion of HPV-immortalized oral keratinocytes may, in part, be associated with the cells' genetic instability. The genetic instability may be due to cells' (1) inability to accumulate intranuclear wt p53 to a threshold level at which p53 upregulates the transcription of WAF1/CIP1 and gadd45, resulting in the loss of cell cycle control and (2) inefficient repair of DNA damage caused by genotoxic agents.
Assuntos
Carcinógenos/toxicidade , Ciclinas/efeitos dos fármacos , Dano ao DNA , Queratinócitos/efeitos dos fármacos , Metilnitronitrosoguanidina/toxicidade , Papillomaviridae , Proteínas/efeitos dos fármacos , Proteína Supressora de Tumor p53/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Transformada , Núcleo Celular/metabolismo , Transformação Celular Neoplásica , Inibidor de Quinase Dependente de Ciclina p21 , Ciclinas/metabolismo , Vetores Genéticos/genética , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Queratinócitos/metabolismo , Boca/citologia , Mutação Puntual , Proteínas/metabolismo , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/metabolismo , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/metabolismo , Regulação para Cima , Proteínas GADD45RESUMO
We previously demonstrated neoplastic conversion of HPV-immortalized human oral keratinocytes by exposing cells to chemical carcinogens, but failed to transform normal human oral keratinocytes with same chemical carcinogens in vitro. Though the reason for different responses of normal and HPV-immortalized oral keratinocytes to chemical carcinogens remains speculative, the difference may be due to the capacity of normal cells and incapacity of HPV-immortalized cells for repairing damaged DNA induced by carcinogens. Since (1) the repair of damaged DNA takes place in G1/G2 phases of cell cycle, (2) wild type p53 plays major role in the induction of transient G1 and/or G2 arrests, and (3) the expression of gadd45 and gadd153 is also associated with the cell cycle arrest and DNA damage, we investigated transient cell cycle arrest and the expression of p53, gadd45 and gadd153 in normal human oral keratinocytes, HPV-immortalized oral keratinocytes, and an oral cancer cell line expressing mutant p53 after exposing cells to UV light. Normal cells demonstrated transient G1 arrest after exposure to UV light, but other tested cells did not. While UV-irradiation significantly increased the level of intranuclear wild type p53 protein in normal cells, it did not alter p53 protein levels in HPV-immortalized and oral cancer cells. The level of gadd45 transcripts was enhanced in all tested cells, but normal cells demonstrated higher increase in the level of gadd45 after UV-exposure compared to other tested cells. The level of gadd153 gene transcripts was only increased in normal oral keratinocytes after UV-irradiation. These data indicate that UV-induced transient G1 arrest in normal oral keratinocytes may be associated with both enhanced levels of intranuclear wild type p53 protein and gadd45 and gadd153 transcripts.
Assuntos
Proteínas Estimuladoras de Ligação a CCAAT , Regulação da Expressão Gênica/efeitos da radiação , Genes p53 , Queratinócitos/efeitos da radiação , Proteínas/genética , Fatores de Transcrição , Raios Ultravioleta , Northern Blotting , Western Blotting , Ciclo Celular/efeitos da radiação , Sobrevivência Celular/efeitos da radiação , Transformação Celular Viral , Células Cultivadas , Dano ao DNA , Imunofluorescência , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Queratinócitos/patologia , Boca/citologia , Papillomaviridae/fisiologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fator de Transcrição CHOP , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Proteína Supressora de Tumor p53/efeitos da radiação , Proteínas GADD45RESUMO
We previously immortalized normal human oral keratinocytes by transfection with recombinant HPV-16 DNA and subsequently exposed the cells to benzo(a)pyrene for 7 days. The exposure to benzo(a)pyrene modified the immortalized cells: the modified cells (HOK-16B-BaP) proliferated in an ordinary culture medium containing physiological calcium level (1.5 mM), but demonstrated only enhanced proliferation capacity without tumor formation in nude mice and failed to show in vitro anchorage-independency. In this study, we further modified the HOK-16B-BaP cells by subculturing the cells in a medium containing benzo(a)pyrene for 6 months. The cells were further modified with a chronic benzo(a)pyrene exposure and were termed HOK-16B-BaP-T cells (1) demonstrated a malignant phenotype in organotypic 'raft' culture, (2) showed in vitro anchorage-independency, (3) developed tumors in nude mice when injected subcutaneously, (4) contained a significantly higher copy number of intact and integrated HPV-16 DNA; (5) contained higher level of HPV-16 E6/E7 messages and E7 protein, (6) were more resistant to transforming growth factor-beta 1 and (7) secreted higher level of vascular endothelial growth factor with molecular weight of 56 kd than parental HOK-16B-BaP cells. However, the levels of p53 and ras proteins and the levels of p53, c-myc and c-fos transcripts in the HOK-16B-BaP-T cells were not different from those in the HOK-16B-BaP cells. The highly conserved coding regions of the p53, c-Ha-ras1, and c-Ki-ras2 genes of the tumor cells were not mutated. These data indicate that the HPV-immortalized human oral keratinocytes can convert to tumorigenic cells by chronic exposure to benzo(a)pyrene. The tumorigenic conversion seems to be associated with (1) the overexpression of viral oncogenes such as E6 and E7 genes, (2) the higher resistance of cells to transforming growth factor-beta 1 and (3) the high secretion of 56 kd vascular endothelial growth factor from the cells.
Assuntos
Benzo(a)pireno/toxicidade , Carcinoma de Células Escamosas/induzido quimicamente , Carcinoma de Células Escamosas/virologia , Cocarcinogênese , Neoplasias Bucais/etiologia , Papillomaviridae/patogenicidade , Animais , Sequência de Bases , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Divisão Celular/efeitos dos fármacos , Linhagem Celular Transformada , Primers do DNA , DNA Viral/análise , Fatores de Crescimento Endotelial/metabolismo , Genes fos , Genes myc , Genes ras , Humanos , Linfocinas/metabolismo , Camundongos , Camundongos Nus , Dados de Sequência Molecular , Neoplasias Bucais/genética , Neoplasias Bucais/patologia , Proteínas Oncogênicas Virais/genética , Papillomaviridae/genética , Proteínas E7 de Papillomavirus , RNA Viral/análise , Fator de Crescimento Transformador beta/farmacologia , Proteína Supressora de Tumor p53/genética , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio VascularRESUMO
Tectorigenin and tectoridin, isolated from the rhizomes of Korean Belamcanda chinensis (Iridaceae) which are used as Chinese traditional medicine for the treatment of inflammation, suppressed prostaglandin E2 production by rat peritoneal macrophages stimulated by the protein kinase C activator, 12-O-tetradecanoylphorbol 13-acetate (TPA), or the endomembrane Ca2+-ATPase inhibitor, thapsigargin. Tectorigenin inhibited prostaglandin E2 production more potently than tectoridin. Neither compound inhibited the release of radioactivity from [3H]arachidonic acid-labeled macrophages stimulated by TPA or thapsigargin. In addition, activities of isolated cyclooxygenase (COX)-1 and COX-2 were not inhibited by the two compounds. Western blot analysis revealed that the induction of COX-2 by TPA or thapsigargin was inhibited by the two compounds in parallel with the inhibition of prostaglandin E2 production. These findings suggest that one of the mechanisms of the anti-inflammatory activities of the rhizomes of Belamcanda chinensis is the inhibition of prostaglandin E2 production by tectorigenin and tectoridin due to the inhibition of the induction of COX-2 in the inflammatory cells.
Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Dinoprostona/metabolismo , Medicamentos de Ervas Chinesas/farmacologia , Isoenzimas/biossíntese , Isoflavonas/farmacologia , Macrófagos Peritoneais/efeitos dos fármacos , Prostaglandina-Endoperóxido Sintases/biossíntese , Animais , Ácido Araquidônico/metabolismo , Ciclo-Oxigenase 1 , Ciclo-Oxigenase 2 , Indução Enzimática/efeitos dos fármacos , Isoenzimas/análise , Isoenzimas/metabolismo , Macrófagos Peritoneais/metabolismo , Masculino , Proteínas de Membrana , Prostaglandina-Endoperóxido Sintases/análise , Prostaglandina-Endoperóxido Sintases/metabolismo , Ratos , Ratos Sprague-Dawley , Acetato de Tetradecanoilforbol/antagonistas & inibidores , Tapsigargina/antagonistas & inibidoresRESUMO
A phase Ilate/II trial of hyperfractionated (HFX) radiation therapy for non-small-cell carcinoma of the lung (NSCCL) was conducted by the Radiation Therapy Oncology Group (RTOG) between 1983 and 1987. Fractions of 1.2 Gy were administered twice daily with greater than or equal to 4 hours between fractions. Patients were randomized to receive minimum total doses of 60.0, 64.8, and 69.6 Gy. After acceptable risks of acute and late effects were found, 74.4 Gy and 79.2 Gy arms were added, and the lowest total dose arms were closed. No significant differences in the risks of acute or late effects in normal tissues were found among the 848 patients analyzed in the five arms; risks of severe or life-threatening pneumonitis were 2.6% for 60.0 to 64.8 Gy, 5.7% for 69.6 to 74.4 Gy, and 8.1% for 79.2 Gy. Among 350 patients who had the same criteria as Cancer and Leukemia Group B (CALGB) protocol 84-33 (American Joint Committee on Cancer Staging [AJCCS], 1984, stage III; Karnofsky performance status [KPS] 70 to 100; less than 6% weight loss), there was a dose response for survival: survival with 69.6 Gy (median, 13.0 months; 2 years, 29%) was significantly (P = .02) better than the lower total doses. There were no differences in survival among the three highest total-dose arms. Comparisons with results in similar patients treated with 60 Gy in 30 fractions of 2.0 Gy 5 days per week for 6 weeks suggest benefit from HFX radiation therapy with 69.6 Gy. Improvement in survival with HFX radiation therapy at 69.6 Gy total dose without increase in normal tissue effects, justifies phase III comparison with standard fractionation alone and combined with systemic chemotherapy in this common presentation of NSCCL.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/radioterapia , Neoplasias Pulmonares/radioterapia , Adulto , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma Pulmonar de Células não Pequenas/patologia , Relação Dose-Resposta à Radiação , Humanos , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Lesões por Radiação/etiologia , Dosagem Radioterapêutica , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
Somatic mutations in the transforming growth factor beta receptor type II (TGF-beta RII) gene have been observed in various human cancers showing microsatellite instability. Most of the mutations observed were additions or deletions of the mononucleotide repeat sequence present in TGF-beta RII coding region, suggesting that the TGF-beta RII may be a target gene of genomic instability in tumorigenesis. Recently, we reported germ-line frameshift mutations in the mononucleotide repeat sequence of the hMSH6 gene, which is believed to be one of the target genes of genomic instability in tumorigenesis, suggesting the possibility of germ-line mutation in mononucleotide repeat sequences. Moreover, one case of germ-line mutation in the TGF-beta RII gene was identified in a hereditary nonpolyposis colorectal cancer (HNPCC) kindred, indicating the involvement of TGF-beta RII inactivation in tumorigenesis of HNPCC. However, germ-line mutation analysis of all of the coding sequences and the mononucleotide repeat sequence of the TGF-beta RII in HNPCC patients has not yet been fully elucidated. Therefore, to further investigate the presence of germ-line mutations, we screened all of the coding region sequences and mononucleotide repeat sequence of TGF-beta RII from 35 HNPCC, 44 suspected HNPCC, and 45 sporadic early-onset colorectal cancer patients. However, no pathogenic mutations other than silent mutations, introgenic mutation, and polymorphisms were identified. Two silent mutations at codons 309 (ACG to ACA) and 340 (CAT to CAC) in the kinase domain located in exon 4 were detected. A 1-bp cytidine deletion was observed 6 bases from the 3' end of intron. Two polymorphisms were identified at codon 389 (AAC to AAT) and at the fourth-to-last base in intron 3. The polymorphism at codon 389 was more frequent in HNPCC (20%; 7 of 35) and suspected HNPCC patients (18%; 8 of 44) than in nonmalignant control group (10%; 5 of 50). Moreover, the frequency was significantly higher in early-onset colorectal cancer patients (31%; 14 of 45). This is the first report of a different frequency of polymorphism in HNPCC, suspected HNPCC, early-onset colorectal cancer patients, and healthy normal individuals. This result suggests that: (a) germ-line mutation of the TGF-beta RII gene may be a rare event during tumorigenesis in HNPCC and sporadic early-onset colorectal cancer; (b) the mononucleotide repeat sequence of the TGF-beta RII gene is an apparent target of genomic instability but not of germ-line mutation; and (c) the polymorphism of codon 389 (AAC to AAT) is frequent, especially in early-onset colorectal cancer patients, in which it is more frequent than in control group.