RESUMEN
The Kamioka Gravitational wave detector (KAGRA) cryogenic gravitational-wave observatory has commenced joint observations with the worldwide gravitational wave detector network. Precise calibration of the detector response is essential for accurately estimating parameters of gravitational wave sources. A photon calibrator is a crucial calibration tool used in laser interferometer gravitational-wave observatory, Virgo, and KAGRA, and it was utilized in joint observation 3 with GEO600 in Germany in April 2020. In this paper, KAGRA implemented three key enhancements: a high-power laser, a power stabilization system, and remote beam position control. KAGRA employs a 20 W laser divided into two beams that are injected onto the mirror surface. By utilizing a high-power laser, the response of the detector at kHz frequencies can be calibrated. To independently control the power of each laser beam, an optical follower servo was installed for power stabilization. The optical path of the photon calibrator's beam positions was controlled using pico-motors, allowing for the characterization of the detector's rotation response. Additionally, a telephoto camera and quadrant photodetectors were installed to monitor beam positions, and beam position control was implemented to optimize the mirror response. In this paper, we discuss the statistical errors associated with the measurement of relative power noise. We also address systematic errors related to the power calibration model of the photon calibrator and the simulation of elastic deformation effects using finite element analysis. Ultimately, we have successfully reduced the total systematic error from the photon calibrator to 2.0%.
RESUMEN
INTRODUCTION: Osteoblasts play essential roles in bone formation and regeneration, while they have low proliferation potential. Recently we established a procedure to directly convert human fibroblasts into osteoblasts (dOBs). Transduction of Runx2 (R), Osterix (X), Oct3/4 (O) and L-myc (L) genes followed by culturing under osteogenic conditions induced normal human fibroblasts to express osteoblast-specific genes and produce calcified bone matrix both in vitro and in vivo Intriguingly, a combination of only two factors, Oct3/4 and L-myc, significantly induced osteoblast-like phenotype in fibroblasts, but the mechanisms underlying the direct conversion remains to be unveiled. MATERIALS AND METHODS: We examined which Oct family genes and Myc family genes are capable of inducing osteoblast-like phenotypic conversion. RESULTS: As result Oct3/4, Oct6 and Oct9, among other Oct family members, had the capability, while N-myc was the most effective Myc family gene. The Oct9 plus N-myc was the best combination to induce direct conversion of human fibroblasts into osteoblast-like cells. DISCUSSION: The present findings may greatly contribute to the elucidation of the roles of the Oct and Myc proteins in osteoblast direct reprogramming. The results may also lead to establishment of novel regenerative therapy for various bone resorption diseases.
Asunto(s)
Fibroblastos/metabolismo , Genes myc , Proteínas de Transporte de Catión Orgánico/genética , Osteoblastos/metabolismo , Transducción Genética , Humanos , FenotipoRESUMEN
Bone morphogenetic protein 4 (BMP4) has potential as an anticancer agent. Recent studies have suggested that BMP4 inhibits the survival of cancer stem cells (CSCs) of neural and colon cancers. Here, we showed that BMP4 paracrinically inhibited tumor angiogenesis via the induction of Thrombospondin-1 (TSP1), and consequently suppressed tumor growth in vivo. Although HeLa (human cervical cancer), HCI-H460-LNM35 (highly metastatic human lung cancer) and B16 (murine melanoma) cells did not respond to the BMP4 treatment in vitro, the growth of xeno- and allografts of these cells was suppressed via reductions in tumor angiogenesis after intraperitoneal treatment with BMP4. When we assessed the mRNA expression of major angiogenesis-related factors in grafted tumors, we found that the expression of TSP1 was significantly upregulated by BMP4 administration. We then confirmed that BMP4 was less effective in suppressing the tumor growth of TSP1-knockdown cancer cells. Furthermore, we found that BMP4 reduced vascular endothelial growth factor (VEGF) expression in vivo in a TSP1-dependent manner, which indicates that BMP4 interfered with the stabilization of tumor angiogenesis. In conclusion, the BMP4/TSP1 loop paracrinically suppressed tumor angiogenesis in the tumor microenvironment, which subsequently reduced the growth of tumors. BMP4 may become an antitumor agent and open a new field of antiangiogenic therapy.
Asunto(s)
Proteína Morfogenética Ósea 4/metabolismo , Neoplasias/metabolismo , Neoplasias/patología , Neovascularización Patológica/metabolismo , Comunicación Paracrina , Trombospondina 1/metabolismo , Animales , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/metabolismo , Línea Celular Tumoral , Proliferación Celular , Células Endoteliales/metabolismo , Células HeLa , Humanos , Melanoma Experimental , Ratones , Transducción de Señal , Proteína Smad1/metabolismo , Proteína Smad5/metabolismo , Carga TumoralRESUMEN
The regenerating gene (Reg) was isolated originally as a gene specifically over-expressed in regenerating pancreatic islets and constitute a growth factor family. Reg gene product (Reg) is important in the pathophysiology of various human inflammatory diseases. Recently, the possible involvement of human REG in the regeneration of salivary ductal epithelial cells of patients with primary Sjögren's syndrome (SS) was reported. However, the expression of the REG family genes in minor salivary glands (MSG) and the occurrence of anti-REG Iα autoantibodies in SS patients were obscured. In this study, we examined the expression of REG family genes in the MSG of SS and screened anti-REG Iα autoantibodies in SS. The mRNA levels of REG family genes in MSG were quantified using real-time reverse transcription-polymerase chain reaction (RT-PCR) and REG Iα expression in the MSG was analysed by immunohistochemistry. The mRNA level of REG Iα in the MSG of SS patients was significantly higher than that of control. REG Iα protein was expressed highly in SS ductal epithelial cells. Anti-REG Iα autoantibodies in the sera were found in 11% of SS. All the MSG in the anti-REG Iα autoantibody-positive group showed REG Iα expression, whereas only 40% showed REG Iα expression in the anti-REG Iα autoantibody-negative group. The anti-REG Iα autoantibody-positive group showed significantly lower saliva secretion and a higher ratio of grade 4 (by Rubin-Holt) in sialography. These data suggest strongly that autoimmunity to REG Iα might play a role in the degeneration of MSG ductal epithelial cells in primary SS.
Asunto(s)
Enfermedades Autoinmunes/inmunología , Litostatina/inmunología , Síndrome de Sjögren/inmunología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Autoanticuerpos/biosíntesis , Autoanticuerpos/fisiología , Enfermedades Autoinmunes/complicaciones , Enfermedades Autoinmunes/genética , Niño , Femenino , Humanos , Interleucina-6/biosíntesis , Interleucina-6/genética , Interleucina-8/biosíntesis , Interleucina-8/genética , Litostatina/biosíntesis , Litostatina/genética , Masculino , Persona de Mediana Edad , Glándulas Salivales Menores/inmunología , Glándulas Salivales Menores/metabolismo , Síndrome de Sjögren/complicaciones , Síndrome de Sjögren/genética , Adulto JovenAsunto(s)
Neoplasias Pulmonares/patología , Linfoma de Células B de la Zona Marginal/patología , Biopsia con Aguja Fina , Diagnóstico Diferencial , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/cirugía , Linfoma de Células B de la Zona Marginal/diagnóstico , Linfoma de Células B de la Zona Marginal/cirugía , Masculino , Persona de Mediana Edad , Monitoreo IntraoperatorioAsunto(s)
Proteínas Portadoras/genética , Proteínas de Transporte de Membrana , Mutación , Osteocondrodisplasias/genética , Adolescente , Animales , Células COS , Niño , Femenino , Humanos , Japón , Masculino , Linaje , Factores de Transcripción , Cromosoma XRESUMEN
The in vivo induction mechanism of a preneoplastic marker enzyme, glutathione S-transferase P-form (GST-P), by a number of carcinogens and some noncarcinogens such as anti-oxidants [Proc. Natl. Acad. Sci. U.S.A. 85 (1984) 3964] has remained to be solved. Among the various administration routes tested, GST-P became immunohistochemically demonstrable in the liver centrilobular zone 3 after 24-48h on administration of prostaglandin J2's, 15-deoxy-Delta(12,14)-PGJ2, PGJ2 and Delta(12)-PGJ2 to male rats via the portal vein, whereby the animals had been pretreated with Soya oil intraperitoneally to exhaust fatty acid binding proteins. Unsaturated aldehydes, 4-hydroxynonenal, crotonaldehyde and acrolein, given by the same route induced putatively preneoplastic single cells positive for GST-P. As these lipid peroxidation end products are the substrates as well as inducers of the enzyme, its physiological function could be their detoxication. These results indicate that GST-P expression can be mediated through lipid peroxidation possibly accounting for induction observed with a wide variety of carcinogens. In addition, present method may also be of use as a direct, simple, rapid, and sensitive in vivo test in examination of other biological responses.
Asunto(s)
Biomarcadores de Tumor/biosíntesis , Carcinógenos/toxicidad , Glutatión Transferasa/biosíntesis , Peroxidación de Lípido , Hígado/efectos de los fármacos , Hígado/metabolismo , Proteínas de Neoplasias , Proteínas del Tejido Nervioso , Prostaglandina D2/análogos & derivados , Animales , Pruebas de Carcinogenicidad/métodos , Carcinógenos/administración & dosificación , Proteínas Portadoras/metabolismo , Proteína de Unión a los Ácidos Grasos 7 , Proteínas de Unión a Ácidos Grasos , Inyecciones Intravenosas , Peroxidación de Lípido/efectos de los fármacos , Neoplasias Hepáticas Experimentales/metabolismo , Masculino , Vena Porta , Lesiones Precancerosas/metabolismo , Prostaglandina D2/administración & dosificación , Prostaglandina D2/farmacología , Ratas , Ratas Sprague-Dawley , Aceite de Soja/administración & dosificaciónRESUMEN
We have recently reported a novel function for carbonyl reductase (CR), namely, its ability to modulate the metastatic potential of malignant mouse cells. Because there are currently no data addressing a similar function for CR in human cancers, the aim of this study was to assess a correlation between survival and metastasis, and CR level in epithelial ovarian cancer. Using anti-CR antibody, immunohistochemical staining was performed on 73 epithelial ovarian cancers, 13 borderline malignant tumours, and 25 benign ovarian tumours for a total of 111 specimens. The combined rate for strongly and weakly positive reactions for CR was 32.0% for benign tumours, 38.5% for borderline malignant tumours, and 61.6% for ovarian cancers. The CR-positive rate was 35.7% (weakly positive alone) for ovarian cancers with retroperitoneal lymph node (RLN) metastasis and 67.8% for those without RLN metastasis (P< 0.05). The 5-year survival rate was 62.7% for the patients with CR-negative cancer and 86.1% for those with CR-positive cancer (P< 0.05). The present results indicate that decreased CR expression in epithelial ovarian cancer is associated with RLN metastasis and poor survival.
Asunto(s)
Oxidorreductasas de Alcohol/biosíntesis , Biomarcadores de Tumor/análisis , Carcinoma/enzimología , Carcinoma/patología , Metástasis Linfática , Neoplasias Ováricas/enzimología , Neoplasias Ováricas/patología , Adulto , Oxidorreductasas de Alcohol/análisis , Carcinoma/tratamiento farmacológico , Femenino , Humanos , Estadificación de Neoplasias , Neoplasias Ováricas/tratamiento farmacológico , Pronóstico , Análisis de SupervivenciaRESUMEN
RB, p53 and p21(Sdi1/WAF1/Cip1) interact in the induction of G1 arrest. We established osteosarcoma cell lines in which a tetracycline-regulatable promoter controls the induction of RB, p53 and p21. By using these cell lines, we investigated whether RB, p53 or p21 regulates, in the same manner or differently, expression and function of E2F-1 and its responsive genes. E2F-1 gene products and transcripts of the E2F-responsive genes decreased in response to RB. Similar changes occurred to p53 and p21 when RB is present. However, in the absence of RB, some of the E2F-responsive genes decreased in response to p53 but not to p21. Thus, RB is a critical component for regulating the E2F-responsive genes, while p53 alone affects only a subset of these genes.
Asunto(s)
Proteínas Portadoras , Proteínas de Ciclo Celular , Ciclinas/metabolismo , Proteínas de Unión al ADN , Regulación de la Expresión Génica/fisiología , Proteína de Retinoblastoma/metabolismo , Factores de Transcripción/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Medio de Cultivo Libre de Suero/metabolismo , Inhibidor p21 de las Quinasas Dependientes de la Ciclina , Ciclinas/fisiología , Factores de Transcripción E2F , Factor de Transcripción E2F1 , Humanos , Proteína de Retinoblastoma/fisiología , Proteína 1 de Unión a Retinoblastoma , Factores de Transcripción/genética , Células Tumorales Cultivadas , Proteína p53 Supresora de Tumor/fisiologíaRESUMEN
Changes in intraluminal pressure in rat colon with aging and with the effects of dietary fiber were measured. A pressure sensor was inserted into the rat large intestine under endoscopic guidance. The intraluminal pressure curve in the colon was recorded, and the motility index was calculated by this curve. The rats were divided into three groups with a fiber-free diet, a cellulose diet (10% w/w), or a pectin diet (10% w/w). Intraluminal pressure was measured in the proximal, middle, and distal colon at 2, 4, 8, 12, and 16 months after birth. Intraluminal pressure in three sites increased with age and decreased in the latter half of the study. The motility index was lower during the course in the fiber groups, especially the pectin group more than the nonfiber group. This result suggests that long-term ingestion of dietary fiber might have a prophylactic effect on the development of diverticula.
Asunto(s)
Fibras de la Dieta , Intestino Grueso/fisiología , Factores de Edad , Animales , Fibras de la Dieta/administración & dosificación , Motilidad Gastrointestinal , Masculino , Presión , Ratas , Ratas Sprague-Dawley , Factores de TiempoRESUMEN
BACKGROUND: Complete hepatic venous isolation and extracorporeal charcoal hemoperfusion (HVI.CHP) can limit systemic exposure to high-dose chemotherapeutic agents when given by hepatic arterial infusion (HAI). The purpose of this study was to determine if the concomitant use of sodium thiosulfate (STS) could further expand the advantages of pharmacologic delivery of HVI.CHP for cisplatin (CDDP) during HAI chemotherapy. METHODS: CDDP (4mg/kg) was administered over 20 minutes via HAI under conditions of HVI.CHP in 14 mongrel dogs. HVI.CHP was performed for 30 minutes after initiation of HAI. During CDDP infusion, 7 dogs each received 400 mg/kg STS (a 100-fold molar ratio to CDDP) over 20 minutes via the prefilter (STS group) circuit line, while the remaining 7 dogs (controls) received no STS. Blood samples were taken serially from the prefilter circuit line (hepatic venous blood), postfilter line, and the left carotid artery (systemic blood). The free and total CDDP concentrations in these samples were determined by flameless atomic absorption spectrophotometry. RESULTS: During 20 minutes HAI of CDDP, the mean CDDP extraction ratios (ER) by CHP filter were always higher in the STS group than in the control group, regardless of the form (free or total) of CDDP. The differences between the STS and control groups in the extraction ratios of free and total CDDP were significant at all time points measured (P < .05). Consequently, systemic exposure to CDDP, as assessed by area under the time-concentration curve of total CDDP, was significantly lower in the STS group than in the control group (P < .05). CONCLUSIONS: These results indicated that concomitant STS infusion could further increase the effect of HVI.CHP on CDDP removal after HAI.
Asunto(s)
Carbón Orgánico/farmacocinética , Cisplatino/metabolismo , Circulación Extracorporea , Hemoperfusión , Venas Hepáticas/metabolismo , Tiosulfatos/farmacocinética , Animales , Perros , Femenino , Masculino , Espectrofotometría Atómica , Factores de TiempoRESUMEN
The localization of three glutathione S-transferase (GST) isoforms in the rat cochlea was examined using specific antibodies against each isoform. GST immunoreactivities were found in particular parts of the cochlea, including the intermediate cells and the basal cells of the stria vascularis and various types of fibrocytes in the spiral ligament. The different cell types showed varying combinations of GST isoforms. The GST immunopositive cells identified in the present study may play a central role in the metabolism and inactivation of endogenous and exogenous ototoxic compounds. The specific arrangements also indicated a possible contribution to the detoxification process in the form of a blood-labyrinth barrier.
Asunto(s)
Cóclea/enzimología , Cóclea/ultraestructura , Glutatión Transferasa/metabolismo , Isoformas de Proteínas/metabolismo , Animales , Especificidad de Anticuerpos/inmunología , Barrera Hematoencefálica/fisiología , Inmunohistoquímica , Microscopía Confocal , Microscopía Electrónica , Neurotoxinas/farmacología , Ratas , Ratas WistarRESUMEN
An osteosarcoma cell line has been established from a soft tissue tumor that occurred spontaneously in a BALB / c mouse. This cell line showed ossification when transplanted into syngeneic mice. To examine the mechanism of bone formation, the expression of mRNAs for osteoblastic and chondroblastic markers and factors associated with ossification has been investigated. In culture, the cells exhibited a spindle shape in the growth phase, but had a polygonal shape in the stationary phase. Reverse transcription-polymerase chain reaction analysis showed that the cells expressed mRNAs for pro-alpha1(I) chain of type I collagen, alkaline phosphatase, osteopontin, osteocalcin, and core binding factor alpha1, suggesting differentiation into the stage of osteoblasts during the stationary phase. After transplantation, histological examination revealed small foci of pale blue material and basophilic networks that were scattered in the tumor tissues at one week. The former stained positive with alcian blue, suggesting a chondroid matrix. Pro-alpha1(II) chain of type II collagen mRNA was expressed at one week. A large part of tumors at two and three weeks consisted of basophilic networks, which stained positive via von Kossa's method, indicating a calcified woven bone. In situ hybridization analysis showed strong expression of osteopontin and osteocalcin mRNAs in tumor cells surrounding the bone matrix. Bone morphogenetic protein-6 and -7 mRNAs were detected in transplanted tumors, but not in cultured cells. These results suggest that the cell line has the properties of an osteoblastic lineage when cultured in vitro and has an ossifying ability through endochondral bone formation processes when transplanted in vivo.
Asunto(s)
Osteosarcoma/patología , Trasplante , Células Tumorales Cultivadas , Fosfatasa Alcalina/biosíntesis , Animales , Desarrollo Óseo/fisiología , Técnicas de Cultivo de Célula/métodos , Subunidades alfa del Factor de Unión al Sitio Principal , Proteínas de Unión al ADN/biosíntesis , Extremidades/diagnóstico por imagen , Femenino , Hibridación in Situ , Ratones , Ratones Endogámicos BALB C , Trasplante de Neoplasias , Osteocalcina/biosíntesis , Osteopontina , Procolágeno/biosíntesis , ARN Mensajero/metabolismo , Radiografía , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Sialoglicoproteínas/biosíntesis , Neoplasias de los Tejidos Blandos/patología , Factores de Tiempo , Factores de Transcripción/biosíntesisRESUMEN
Microsatellite polymorphism due to differences in CT dinucleotide repeats was demonstrated in intron 14 of the canine BRCA1 gene. Genotype analysis of 103 unrelated dogs from 30 different breeds detected the presence of five alleles, including 10 of the expected 15 genotypes. Gene frequencies were biased and all alleles with the exception of one were below 0.1. This polymorphism, which occurs at the intron of canine BRCA1 should prove to be a useful marker for detecting the loss of heterozygosity (LOH). One of the more notable findings of the present study was the detection of homozygotes of rare alleles. This finding identified an accumulation of rare alleles in specific canine breeds and demonstrated the usefulness of this characteristic for the biological study of dog evolution.
Asunto(s)
Neoplasias de la Mama/veterinaria , Repeticiones de Dinucleótido/genética , Enfermedades de los Perros/genética , Genes BRCA1/genética , Polimorfismo Genético , Animales , Neoplasias de la Mama/genética , ADN de Neoplasias/química , ADN de Neoplasias/genética , ADN de Neoplasias/aislamiento & purificación , Perros , Femenino , Intrones/genética , Reacción en Cadena de la Polimerasa/veterinaria , Análisis de Secuencia de ADN/veterinariaRESUMEN
A cDNA coding for feline liver xanthine dehydrogenase (XDH, EC 1.1.204) was amplified by RT-PCR and cloned for determining the sequence. The clones contained an open reading frame of 4002 base pairs encoding 1333 amino acid residues. The calculated molecular weight and isoelectric point were approximately 146 kDa and 7.0. Comparison of the deduced amino acid sequences indicated remarkable high homology, i.e., the amino acid residues of feline XDH shared approximately 90%, 87%, 87% and 86% identity with those of human, bovine, rat and mouse, respectively. The anino acid sequences of two putative iron-sulfur centers, one NAD binding site and one molybdenum binding site were well conserved among mammalian animals.
Asunto(s)
Gatos/metabolismo , Hígado/enzimología , Xantina Deshidrogenasa/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Bovinos , Clonación Molecular , ADN Complementario/química , ADN Complementario/genética , Humanos , Ratones , Datos de Secuencia Molecular , ARN/química , ARN/genética , ARN/aislamiento & purificación , Ratas , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/veterinaria , Alineación de Secuencia , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido , Xantina Deshidrogenasa/químicaRESUMEN
BACKGROUND: KMD-3213 is an alpha1A-adrenoceptor-selective antagonist currently being developed for the treatment of urinary outlet obstruction in patients with benign prostatic hyperplasia. In the present study, the uroselectivity of KMD-3213 was evaluated and compared with that of prazosin and tamsulosin in a decerebrate dog model. METHODS: Intercollicular decerebration was carried out in male mongrel dogs under anesthesia. The inhibitory effects of intravenously and intraduodenally administered compounds on the increase in intraurethral pressure (IUP) induced by electrical stimulation of the hypogastric nerve were estimated. Systemic blood pressure was measured simultaneously. RESULTS: The alpha1-antagonists tested produced a dose-dependent inhibition of the induced IUP response and decreased mean blood pressure (MBP). The ID50 of KMD-3213, tamsulosin and prazosin for IUP (dose required to inhibit the increase in IUP by 50%) was 3.15, 1.73 and 11.8 microg/kg i.v., respectively, and the ED20 for the hypotensive effect (dose required to reduce MBP by 20%) was 8.03, 0.59 and 2.46 microg/kg i.v., respectively. The data indicate that uroselectivity (ED20/ID50) of KMD-3213 is 12- and 7.5-fold higher than that of prazosin and tamsulosin, respectively. When the drugs were administered intraduodenally, KMD-3213 was sufficiently absorbed from the digestive tract and continued to demonstrate at least 3.8-fold higher uroselectivity than tamsulosin. CONCLUSION: Based on these findings, KMD-3213 appears to be an effective orally active compound for decreasing urethral resistance during micturition that does not induce any negative cardiovascular effects in patients with benign prostatic hyperplasia.
Asunto(s)
Antagonistas Adrenérgicos alfa/farmacología , Presión Sanguínea/efectos de los fármacos , Presión Sanguínea/fisiología , Estado de Descerebración/fisiopatología , Indoles/farmacología , Uretra/efectos de los fármacos , Uretra/fisiología , Animales , Perros , Masculino , Presión , PróstataRESUMEN
To clarify the carcinogenic factors--whether it is the kind of carcinogen or their length of exposure--that determine whether colorectal cancer develops from an adenoma or develops de novo in the absence of an adenoma, we histopathologically analyzed a total of 229 rat colon tumors induced by administration of 1,2-dimethyl-hydrazine (DMH) or N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) for three or 15 weeks. In the three-week-exposure groups, 71% of DMH-induced carcinomas and 82% of MNNG-induced carcinomas coexisted with low-grade dysplasia (adenomatous remnant). However, in the 15-week-exposure groups, lowgrade dysplasia was observed in only 10% of DMH-induced and 27% of MNNG-induced carcinomas. Even in the tumors smaller than 20 mm3, it was observed in only 10% of DMH-induced and 32% of MNNG-induced carcinomas. Furthermore, carcinomas without low-grade dysplasia predominated from the initial period of tumor occurrence. Next, we investigated association of K-ras and APC gene mutations with these carcinogenesis patterns in 80 tumors. K-ras mutations were not detected in any tumors induced by three weeks of exposure. However, in the 15-week-exposure groups, this mutation was observed in 57% of DMH-induced tumors and 13% of MNNG-induced tumors. APC mutations in the region homologous to the human mutation cluster region were observed in only 6% of tumors. Thus, our results suggest that the carcinogenesis patterns in rat colon are dependent on the length of exposure to carcinogen and that K-ras mutations were partly involved in a subset of them.
Asunto(s)
Carcinógenos/administración & dosificación , Carcinoma/inducido químicamente , Neoplasias del Colon/inducido químicamente , 1,2-Dimetilhidrazina/administración & dosificación , Animales , Carcinoma/genética , Carcinoma/patología , Neoplasias del Colon/genética , Neoplasias del Colon/patología , Genes APC/genética , Genes ras/genética , Metilnitronitrosoguanidina , Mutación , Ratas , Ratas Endogámicas F344 , Factores de TiempoRESUMEN
Benastatin A, isolated from Streptomyces bacteria, is reported to inhibit mammalian glutathione transferases (GSTs). Since GST inhibitors such as ethacrynic acid are suggested to induce apoptosis in some cell lines, the effect of benastatin A on the survival of mouse colon 26 adenocarcinoma cells was compared with that of ethacrynic acid. When cells in stationary phase were treated with benastatin A, viable cells were found to be dose-dependently decreased after 3 days. In the case of ethacrynic acid, this became apparent within 24 h. Electrophoretic analysis revealed DNA fragmentation, indicating that cell loss was due to apoptosis in both cases. The dominant GST in colon 26 cells was identified as the class Pi-form (GST-II), and the activities in crude extracts as well as purified GST-II were almost completely inhibited by 50 microM ethacrynic acid. Immunoblot and northern blot analyses revealed increased GST-II protein and mRNA levels in cells treated with ethacrynic acid. Benastatin A did not significantly affect the activity in the crude extract even at 20 microM, a 10-fold higher concentration than that which almost completely inhibited the activity of purified GST-II. However, GST activity and GST-II protein were decreased in colon 26 cells treated with benastatin A for 5 days, no significant activity being detected in the range of 16 - 20 microM. In addition, beta-actin and bax mRNAs were also decreased in a dose-dependent manner. Furthermore, flow cytometric analysis of colon 26 cells revealed that benastatin A blocked the cell cycle at the G1/G0 phase. Thus, benastatin A also induces apoptosis of colon 26 cells, but this is unlikely to be due to inhibition of GST activity.
Asunto(s)
Adenocarcinoma/patología , Apoptosis/efectos de los fármacos , Benzo(a)Antracenos/farmacología , Neoplasias del Colon/patología , Inhibidores Enzimáticos/farmacología , Naftacenos , Adenocarcinoma/tratamiento farmacológico , Adenocarcinoma/enzimología , Animales , Ciclo Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Neoplasias del Colon/tratamiento farmacológico , Neoplasias del Colon/enzimología , Ácido Etacrínico/farmacología , Gutatión-S-Transferasa pi , Glutatión Transferasa/antagonistas & inhibidores , Glutatión Transferasa/biosíntesis , Glutatión Transferasa/genética , Glutatión Transferasa/metabolismo , Isoenzimas/antagonistas & inhibidores , Isoenzimas/biosíntesis , Isoenzimas/genética , Isoenzimas/metabolismo , Ratones , ARN Mensajero/biosíntesis , ARN Mensajero/genética , Células Tumorales Cultivadas/efectos de los fármacosRESUMEN
The aim of this study was to evaluate the phase I aspects of super high-dose chemotherapy for advanced liver cancer with combined use of PIHP and PBSCT. In 4 patients with HCC and 1 patient with colonic liver metastases, peripheral blood stem cells (PBSC) were mobilized by either i.v. infusion of ETP (180 mg/m2/day for 3 days) or i.a. infusion of doxorubicin (100-120 mg/m2). In 3 (60%) of 5 patients, PBSC for PBSCT were harvested in effective quantities (CFU-GM > or = 2 x 10(5)/kg or CD 34 positive cells > or = 2 x 10(6)/kg). In these 3 patients, a repeated PIHP with either doxorubicin, 5-fluorouracil, or CDDP was carried out 4 weeks after the 1st PIHP. Thereafter, auto-PBSCT was intravenously administered 2 days after PIHP. In the repeated PIHP treatments, although anti-cancer drugs were administered at doses equivalent to or even higher than those administered at the 1st PIHP, bone marrow suppressions were transient and well tolerated. Fatal complications were not observed in any patients. These results indicate that with the combined use of PIHP and PBSCT, high-dose regional chemotherapy of the liver can be safely repeated without systemic toxicities.